Anti-Actived-Caspase-3 p17 Antibody (A30255)

Autophagy can be a pro-survival or a pro-death mechanism depending on the context. The role of autophagy in intracerebral hemorrhage (ICH) remains elusive. In this study, in vivo and in vitro experiments have been carried out to investigate the role of autophagy after ICH. Collagenase-induced ICH model in mouse was made for in vivo experiments. Primary cortical neurons cultures were exposed to hemin to mimic ICH in vitro. 3-Methyladenine (3-MA) and rapamycin (RAP) were administrated both in vivo and in vitro. We first measured brain water content and cell death after ICH in model. Expression of LC3, p62/SQSTM1 (p62), Beclin1, Caspase3 and Bcl-2, which have been found related to autophagy and apoptosis, were assessed both in vivo and in vitro. Furthermore, NF-κB was detected to explore the potential mechanisms. We found brain edema in ICH model in mouse and the number of Propidium Iodide (PI)-positive cells both in vivo and in vitro were decreased by 3-MA pretreated. Simultaneously, both in vivo and in vitro, 3-MA significantly decreased the expression of LC3-II and Beclin-1, and maintained p62 at high level after ICH. Furthermore, pretreatment with 3-MA downregulated the level of cleaved caspase-3 but upregulated the Bcl-2 level. Conversely, RAP pretreatment reversed all these results above. These data indicated that autophagy activation may deprave ICH induced brain injury in ICH model and neuro-damage may be related to regulating of NF-κB pathway and thereby promote inflammation and apoptosis, thus might provide novel therapeutic interventions for ICH.

Isoflurane exposure induces apoptosis in cultured cells and in the developing brain, while the underlying mechanism remains largely unclarified. This study was designed to determine whether the disruption of mitoK_ATP-mediated ATP balance was involved in the cytotoxicity of isoflurane. Human neuroglioma cells U251 and 7-day-old mice were treated with isoflurane. A specific mitoK_ATP antagonist 5-HD was used, and the cellular ATP levels, NAD⁺/NADH ratios, and mitochondrial transmembrane potential (ΔΨ_m) were measured. Our data showed that the blockage of mitoK_ATP by 5-HD mitigated the isoflurane-induced ΔΨ_m disruption, reactive oxygen species (ROS) accumulation, and apoptosis in U251 cells. Moreover, we found that the toxic effect of isoflurane was not observed in the first 2-h exposure; instead, the cellular ATP levels and NAD⁺/NADH ratios were markedly increased. The reduction of ATP levels and NAD⁺/NADH ratios was only detected after this initial phase. This dynamical effect of isoflurane was blocked by 5-HD. In contrast, a ROS scavenger NAC sustained the isoflurane-induced ATP elevation. Similar results were observed in animal studies. And again, 5-HD attenuated isoflurane-induced cognitive disorders in the Intellicage test, a system that assesses place learning behavior in a social environment. Our study uncovered a potential mechanism underlying isoflurane's toxicity with a therapeutic future.

Isoflurane, a commonly used volatile anesthetic, causes widespread neuronal apoptosis in the developing brain of rodents. Signal transducer and activator of transcription-3 (STAT3) signaling is crucial for cell survival during the neural network establishment period. The aim of this study was to determine whether isoflurane would target STAT3 to deliver its neurotoxicity. Mice at postnatal day 7 and primary cortical neurons cultured for 5 days were treated with isoflurane. Our data showed that isoflurane exposure downregulated the STAT3 survival pathway in the brain of mice and in primary neurons, whereas the mRNA levels of STAT3 remained unchanged after isoflurane exposure. We found that inhibiting the activity of calcineurin, which specifically promotes STAT3 degradation, alleviated isoflurane-induced neural apoptosis. Further studies showed that isoflurane increased calcineurin activity and that the inositol 1,4,5-trisphosphate-sensitive Ca(2+) channel was involved in these isoflurane-induced molecular cascades. These findings suggest that isoflurane-induced neurotoxicity may stem from STAT3 degradation, partially through the activation of calcineurin.

Polybrominated diphenyl ethers (PBDEs) are widely used flame retardants and are ubiquitous in the environment and human tissues. Recent evidence has demonstrated that PBDE-induced neurotoxicity is associated with neuronal apoptosis via interfering with the calcium ion (Ca²⁺) homeostasis; however, the underlying mechanisms remain elusive. Thus, we sought to investigate the role of Ca²⁺ homeostasis in PBDE-47-induced neuronal apoptosis. Here, we showed that PBDE-47 significantly decreased neuronal number while increased neuronal apoptosis in vitro and in vivo, as manifested by an increased percentage of Annexin V-positive staining cells and caspase-3 activation in human neuroblastoma SH-SY5Y cells and hippocampal neurons of rats. Further study identified that PBDE-47 elicited ΔΨ_m collapse following an early and sustained [Ca²⁺] _i, overload, as well as stimulated cytochrome c release from mitochondria into the cytosol in SH-SY5Y cells and rat hippocampal tissue. Interestingly, the extracellular Ca²⁺ chelator ethylene glycol-bis (2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) blocked PBDE-47-induced [Ca²⁺] _i elevation, ΔΨ_m collapse, cytochrome c release, and caspase-3 activation in SH-SY5Y cells, whereas the intracellular Ca²⁺ chelator 1,2-bis (2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM) had no influences on them, indicating that the [Ca²⁺] _i overload originates primarily from extracellular Ca²⁺ component rather than from intracellular calcium storage and that the increase in [Ca²⁺] _i is a major contributor to ΔΨ_m collapse and subsequent neuronal apoptosis. Overall, these findings suggest that PBDE-47 affects Ca²⁺ homeostasis as a crucial event in activation of neuronal death associated with mitochondria and provide novel insight into the mechanism of action underlying PBDE neurotoxicity.

Centrosome amplification is frequent in cancer, but the underlying mechanisms remain unclear. Here we report that disruption of the Kruppel-like factor 14 (KLF14) gene in mice causes centrosome amplification, aneuploidy and spontaneous tumorigenesis. Molecularly, KLF14 functions as a transcriptional repressor of Plk4, a polo-like kinase whose overexpression induces centrosome overduplication. Transient knockdown of KLF14 is sufficient to induce Plk4-directed centrosome amplification. Clinically, KLF14 transcription is significantly downregulated, whereas Plk4 transcription is upregulated in multiple types of cancers, and there exists an inverse correlation between KLF14 and Plk4 protein expression in human breast and colon cancers. Moreover, KLF14 depletion promotes AOM/DSS-induced colon tumorigenesis. Our findings reveal that KLF14 reduction serves as a mechanism leading to centrosome amplification and tumorigenesis. On the other hand, forced expression of KLF14 leads to mitotic catastrophe. Collectively, our findings identify KLF14 as a tumour suppressor and highlight its potential as biomarker and therapeutic target for cancer.

Evidence has shown that the activation of the autophagy pathway after experimental subarachnoid hemorrhage (SAH) protects against neuronal damage. Tert-butylhydroquinone (tBHQ), a commonly used nuclear factor erythroid 2-related factor 2 (Nrf2) activator, was found to significantly enhance autophagy activation. The aim of this study was to explore the effect of tBHQ treatment on early stage brain injury at 24 h after SAH. The results showed that tBHQ treatment failed to stimulate an effective anti-oxidative effect at 24 h after the SAH operation, but succeeded in ameliorating early brain injury, including alleviated brain edema, BBB disruption, neuronal degeneration and neurological deficits. Further exploration found that tBHQ treatment significantly increased the expression of Beclin-1 and the ratio of microtubule-associated protein 1 light chain 3 (LC3)-II to LC3-I, suggesting that autophagy was enhanced after tBHQ treatment. Moreover, tBHQ treatment restored Bcl-2 and Bax expression and reduced caspase-3 cleavage, suggesting the protective effect of tBHQ treatment in ameliorating brain injury after SAH. Furthermore, tBHQ enhanced autophagy activation, decreased neuronal degeneration and improved the neurological score after SAH in Nrf2-deficient mice. Taken together, these findings suggest that tBHQ treatment exerts neuro-protective effects against EBI following SAH by enhancing Nrf2-independent autophagy. Therefore, tBHQ is a promising therapeutic agent against EBI following SAH.

We investigated potential mechanisms of acute injury in pubertal mice testes after exposure to carbon ion radiation (CIR). Serum testosterone was measured following whole-body irradiation with a 2Gy carbon ion beam. Comparative proteomic profiling and Western blotting were applied to identify potential biomarkers and measure protein expression, and terminal dUTP nick end-labeling (TUNEL) was performed to detect apoptotic cells. Immunohistochemistry and immunofluorescence were used to investigate protein localization. Serum testosterone was lowest at 24h after CIR, and 10 differentially expressed proteins were identified at this time point that included eIF4E, an important regulator of initiation that combines with mTOR and 4EBP1 to control protein synthesis via the mTOR signaling pathway during proliferation and apoptosis. Protein expression and localization studies confirmed their association with acute injury following exposure to CIR. These three proteins may be useful molecular markers for detecting abnormal spermatogenesis following exposure to environmental and therapeutic radiation.

Nasopharyngeal carcinoma (NPC) is primarily treated by chemoradiation. However, how to promote radiation sensitivity in NPC remains a challenge. Salinomycin is potentially useful for the treatment of cancer. This study aimed to explore the radiosensitivity of salinomycin on human nasopharyngeal carcinoma cell line CNE-2. CNE-2 were treated with salinomycin or irradiation, alone or in combination. The cytotoxicity effects of salinomycin were measured using CCK-8 assay. Clonogenic survival assay was used to evaluate the effects of salinomycin on the radiosensitivity of CNE-2. The changes of cell cycle distribution and apoptosis were assayed using flow cytometry. The expression of Caspase3/Bax/Bal-2 was detected by Western blotting. DNA damage was detected via γ-H2AX foci counting. The results showed that salinomycin induced apoptosis and G2/M arrest, increased Bax and cleaved Caspase3, decreased Bcl-2 expression, and increased the formation of γ-H2AX nuclear foci. These data suggest that salinomycin may be a radiosensitizer for NPC radiotherapy.

Ultrasound-targeted microbubble destruction (UTMD) technique is thought to improve the chemotherapeutic agent delivery from microbubbles (MBs) in tumor tissues and reduce the side effects in non-tumor tissues. Multiple myeloma (MM) is a bone marrow cancer and remains to be an incurable disease. In this study, we used the UTMD technique to investigate the inhibitory effect of our developed novel reagent on MM cancer stem cells (CD138(-)CD34(-)MM CSCs) that are MM cells with CD138(-)CD34(-) phenotypes, responsible for MM-initiating potential, drug resistance and eventual relapse. The preparatory steps of novel reagent was first epirubicin (EPI)-loaded in the lipid MBs that was consisted of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000]-biotin, dipalmitoyl-phosphatidylglycerol and 25-NBD-cholesterol, then anti-ABCG2 monoclonal antibody (mAb) was conjugated onto the MB surface to form EPI-MBs+mAb. CD138(-)CD34(-)MM CSCs were isolated from human MM RPMI 8226 cell line by the magnetic associated cell sorting method. The results showed that the attenuated proliferation, migration and invasion ability, and increased apoptosis were observed when MM CSCs were incubated with a various agents. EPI-MBs+mAb combined with therapeutic ultrasound significantly promoted the MM CSC apoptosis compared with EPI, EPI-MBs alone or EPI-MBs+mAb without ultrasound exposure. These results suggest that the developed EPI-MBs+mAb combined with therapeutic ultrasound remarkably induced MM CSC apoptosis in vitro.

Recent studies have demonstrated that miR-34a expression is significantly upregulated and associated with apoptosis in nonalcoholic fatty liver disease (NAFLD). Carnosic acid (CA) is a novel antioxidant and a potential inhibitor of apoptosis in organ injury, including liver injury. This study aimed to investigate the signaling mechanisms underlying miR-34a expression and the antiapoptotic effect of CA in NAFLD. CA treatment significantly reduced the high-fat diet (HFD)-induced elevations in aminotransferase activity as well as in serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and malondialdehyde (MDA) levels but increased serum high-density lipoprotein cholesterol (HDL-C) and hepatic superoxide dismutase (SOD) levels. Moreover, CA treatment ameliorated the increase in cleaved caspase-3 caused by HFD exposure and completely reversed the HFD-induced decreases in manganese superoxide dismutase (MnSOD) and B-cell lymphoma-extra large expression. CA also counteracted the HFD- or palmitic acid (PA)-induced increases in caspase-3 and caspase-9 activity. Mechanistically, CA reversed the HFD- or PA-induced upregulation of miR-34a, which is the best-characterized regulator of SIRT1. Importantly, the decrease in miR-34a expression was closely associated with the activation of the SIRT1/p66shc pathway, which attenuates hepatocyte apoptosis in liver ischemia/reperfusion injury. A dual luciferase assay in L02 cells validated the modulation of SIRT1 by CA, which occurs at least partly via miR-34a. In addition, miR-34a overexpression was significantly counteracted by CA, which prevented the miR-34a-dependent repression of the SIRT1/p66shc pathway and apoptosis. Collectively, our results support a link between liver cell apoptosis and the miR-34a/SIRT1/p66shc pathway, which can be modulated by CA in NAFLD.

The role of NR4A1 in apoptosis is controversial. Pancreatic β-cells often face endoplasmic reticulum (ER) stress under adverse conditions such as high free fatty acid (FFA) concentrations and sustained hyperglycemia. Severe ER stress results in β-cell apoptosis. The aim of this study was to analyze the role of NR4A1 in ER stress-mediated β-cell apoptosis and to characterize the related mechanisms. We confirmed that upon treatment with the ER stress inducers thapsigargin (TG) or palmitic acid (PA), the mRNA and protein levels of NR4A1 rapidly increased in both MIN6 cells and mouse islets. NR4A1 overexpression in MIN6 cells conferred resistance to cell loss induced by TG or PA, as assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and TUNEL assays indicated that NR4A1 overexpression also protected against ER stress-induced apoptosis. This conclusion was further confirmed by experiments exploiting siRNA to knockdown NR4A1 expression in MIN6 cells or exploiting NR4A1 knock-out mice. NR4A1 overexpression in MIN6 cells reduced C/EBP homologous protein (CHOP) expression and Caspase3 activation induced by TG or PA. NR4A1 overexpression in MIN6 cells or mouse islets resulted in Survivin up-regulation. A critical regulatory element was identified in Survivin promoter (-1872 bp to -1866 bp) with a putative NR4A1 binding site; ChIP assays demonstrated that NR4A1 physically associates with the Survivin promoter. In conclusion, NR4A1 protects pancreatic β-cells against ER stress-mediated apoptosis by up-regulating Survivin expression and down-regulating CHOP expression, which we termed as "positive and negative regulation."

Forkhead box C2 (Foxc2) protein is a transcription factor in regulation of development, metabolism, and immunology. However, the regulatory mechanisms of Foxc2 on proliferation and apoptosis of preadipocytes are unclear. In this study, we found that high-fat-diet-induced obesity elevated the expression of Foxc2 and cyclin E after 6 weeks. Additionally, Foxc2 suppressed preadipocyte differentiation, increased cell counts and augmented G1-S transition of preadipocytes, along with the elevation of cyclin E expression and the reduction levels of p27 and p53. Furthermore, Foxc2 knockdown reduced early apoptotic cells with accompanying reduction of mitochondrial membrane potential and increased fragmentation of genomic DNA. We show that Foxc2 reduces the expression of Bax, caspase-9, and caspase-3 in both serum-starved and palmitic acid-induced cell apoptotic models, which confirms the anti-apoptotic role of Foxc2. Moreover, the protein kinase B (Akt)/mammalian target of rapamycin (mTOR)C1 signaling pathway and the ERK/mTORC1 signaling pathway were activated along with preadipocyte proliferation in response to Foxc2 overexpression, whereas apoptosis marker genes were downregulated during this process. Those effects were blocked by the interference of Foxc2 or signal pathways specific inhibitors. These data collectively reveal that Foxc2 enhances proliferation of preadipocytes and inhibits apoptosis of preadipocytes by activating the Akt/mTORC1 and ERK/mTORC1 signaling pathways.

Carnosic acid (CA), found in rosemary, has been reported to have antioxidant and antiadipogenic properties. Here, we investigate the molecular mechanism by which CA inhibits hydrogen peroxide (H2O2)-induced injury in HepG2 cells. Cells were pretreated with 2.5-10 μmol/L CA for 2 h and then exposed to 3 mmol/L H2O2 for an additional 4 h. CA dose-dependently increased cell viability and decreased lactate dehydrogenase activities. Pretreatment with CA completely attenuated the inhibited expression of manganese superoxide dismutase (MnSOD) and the B-cell lymphoma-extra large (Bcl-xL), and reduced glutathione activity caused by H2O2, whereas it reversed reactive oxygen species accumulation and the increase in cleaved caspase-3. Importantly, sirtuin 1 (SIRT1), a NAD(+)-dependent deacetylase, was significantly increased by CA. Considering the above results, we hypothesized that SIRT1 may play important roles in the protective effects of CA in injury induced by H2O2. As expected, SIRT1 suppression by Ex527 (6-chloro-2,3,4,9-tetrahydro-1H-carbazole-1-carboxamide) and siRNA-mediated SIRT1 silencing (si-SIRT1) significantly aggravated the H2O2-induced increased level of cleaved caspase-3 but greatly reduced the decreased expression of MnSOD and Bcl-xL. Furthermore, the positive regulatory effect of CA was inhibited by si-SIRT1. Collectively, the present study indicated that CA can alleviate H2O2-induced hepatocyte damage through the SIRT1 pathway.

O(2)-(2,4-dinitro-5-{[2-(12-en-28-b-d-galactopyranosyl-oleanolate-3-yl)-oxy-2-oxoethyl]amino}phenyl)1-(N-hydroxyethylmethylamino)diazen-1-ium-1,2-diolate (NOAD), a novel NO-releasing derivative of oleanolic acid (OA), is an active cytotoxic component. In this study, NOAD induced a rise in intracellular NO levels and showed cytotoxic effects which were prevented by hemoglobin (NO scavenger). Meanwhile, NOAD induced G2/M phase cell cycle arrest in a concentration-dependent manner. Analysis of the cell cycle regulatory proteins demonstrated that NOAD did not change the steady-state levels of cyclin A, cyclin B, cyclin E, Cdk2 and Cdk4, but decreased the protein levels of Cdk1 and Cdc25C. Meanwhile, the levels of phosphorylation of Cdc25C and Cdk1 were significantly increased by NOAD in a concentration-dependent manner. Moreover, NOAD modulated the phosphorylation of protein kinases Chk2. During the G2/M arrest, cyclin-dependent kinase inhibitors (CDKIs), p21(WAF1/CIP1) and p27(kip1) were increased in a concentration-dependent manner. In addition, NOAD also caused a marked increase in the apoptotic cells, as characterized by fragmented nuclei, sub G1 formation, the level of 8-OHDG increase and poly (ADP-ribose) polymerase (PARP) cleavage, which was associated with activation of caspase-3, caspase-8 and caspase-9. Up-regulation of Bax and down-regulation of Bcl-2 were also observed in Bel-7402 cells treated with NOAD. These data suggest that NOAD produces anti-tumor effect via induction of G2/M cell cycle arrest and apoptosis.

Paclitaxel, isolated from Taxus brevifolia, is considered to be an efficacious agent against a wide spectrum of human cancers, including human cervical cancer. However, dose-limiting toxicity and high cost limit its clinical application. Curcumin, a nontoxic food additive, has been reported to improve paclitaxel chemotherapy in mouse models of cervical cancer. However, the underlying mechanisms remain unclear. In this study, two human cervical cancer cell lines, CaSki [human papilloma virus (HPV)16-positive] and HeLa (HPV18-positive), were selected in which to investigate the effect of curcumin on the anticancer action of paclitaxel and further clarify the mechanisms. Flow cytometry and MTT analysis demonstrated that curcumin significantly promoted paclitaxel-induced apoptosis and cytotoxicity in the two cervical cell lines compared with that observed with paclitaxel alone (P<0.05). Reverse transcription-polymerase chain reaction indicated that the decline of HPV E6 and E7 gene expression induced by paclitaxel was also assisted by curcumin. The expression levels of p53 protein and cleaved caspase-3 were increased significantly in the curcumin plus paclitaxel-treated HeLa and CaSki cells compared with those in the cells treated with paclitaxel alone (P<0.01). Significant reductions in the levels of phosphorylation of IκBα and the p65-NF-κB subunit in CaSki cells treated with curcumin and paclitaxel were observed compared with those in cells treated with paclitaxel alone (P<0.05). This suggests that the combined effect of curcumin and paclitaxel was associated with the NF-κB-p53-caspase-3 pathway. In conclusion, curcumin has the ability to improve the paclitaxel-induced apoptosis of HPV-positive human cervical cancer cell lines via the NF-κB-p53-caspase-3 pathway. Curcumin in combination with paclitaxel may provide a superior therapeutic effect on human cervical cancer.

What is the central question of this study? What are the ultrastructural changes of the caecal mucosa and the status of epithelial cellular apoptosis and oxidative reactions in lactating goats after prolonged feeding with a high-concentrate diet? What is the main finding and its importance? High-concentrate diet results in ultrastructural damage to the caprine caecal epithelium. Increased oxidative and decreased antioxidative reactions are involved in the process of activating epithelial apoptosis in the caecal epithelium of goats fed a high-concentrate diet. Our results provide new insight into the relationship between abnormal fermentation in the hindgut and damage to the intestinal mucosal barrier. The effect of feeding a high-concentrate diet (HC) to lactating ruminants on their hindgut epithelial structure remains unknown. In this study, 12 lactating goats were randomly assigned to either HC (65% of dry matter as concentrate; n = 6) or a low-concentrate diet (LC; 35% of dry matter as concentrate; n = 6). After 10 weeks, the epithelial ultrastructure and cell apoptotic status in the caecal mucosa were determined by transmission electron microscopy and TUNEL, respectively. The results showed that the level of free lipopolysaccharide (P < 0.05), total volatile fatty acid concentrations (P < 0.1) and starch content (P < 0.05) in the caecal digesta were significantly increased in HC- compared with LC-fed goats. The HC-fed goats exhibited obvious epithelial cellular damage, with widened tight junction spaces, nuclear breakdown and mitochondrial swelling. Compared with their LC-fed counterparts, HC-fed goats showed greater apoptosis in the caecal epithelium, as evidenced by more TUNEL-positive apoptotic cells. Western blot analysis showed that there was no significant difference in activated caspase-3, Bax protein expression in caecal epithelial mucosa between HC- and LC-fed goats (P > 0.05). However, the level of malondialdehyde content in the caecal epithelium from HC-fed goats was markedly higher than that in LC-fed goats (P < 0.05), whereas the level of glutathione peroxidase and the superoxide dismutase activity were significantly decreased. Gene expressions of cytokines, including interleukin-1β, interleukin-6, interleukin-10, tumour necrosis factor-α and interferon-γ, as well as myeloperoxidase activity in the caecal mucosa did not show any significant difference between HC- and LC-fed goats. These results indicate that feeding a high-concentrate diet to lactating goats for a prolonged period results in abnormal fermentation and structural disruption in the hindgut, which is accompanied by greater cellular apoptosis and an enhanced oxidative stress response.

Methylmercury (MeHg) is an environmental toxin which induces cell death specific for the nervous systems. Here we show that MeHg causes neuronal cell death through the suppression of the tropomyosin receptor kinase A (TrkA) pathway, and that compounds activating the TrkA pathway prevent MeHg-induced nerve damage in vitro and in vivo. We first investigated the mechanism of MeHg-induced neurotoxicity in differentiating neurons using PC12 cells. Exposure to 100nM MeHg for 1day induced apoptosis in differentiating PC12 cells. Further, MeHg-induced apoptosis was preceded by inhibition of neurite extension, as determined by ELISA analyses of the neurite-specific protein neurofilament triplet H protein (NF-H). To determine the mechanism of MeHg-induced apoptosis, we evaluated the effects of MeHg on the TrkA pathway, which is known to regulate neuronal differentiation and viability. Western blot analysis demonstrated that, like the TrkA phosphorylation inhibitor K252a, MeHg inhibited phosphorylation of TrkA and its downstream effectors. Furthermore, GM1 ganglioside and its analog MCC-257, which enhance TrkA phosphorylation, overcame the effect of MeHg in neurons, supporting the involvement of the TrkA pathway in MeHg-induced nerve damage. Finally, we demonstrated that MCC-257 rescued the clinical sign and pathological changes in MeHg-exposed rats. These findings indicate that MeHg-induced apoptosis in neuron is triggered by inhibition of the TrkA pathway, and that GM1 ganglioside and MCC-257 effectively prevent MeHg-induced nerve damage.

The embryonic stem cell (ESC)-enriched miR-294/302 family and the somatic cell-enriched let-7 family stabilizes the self-renewing and differentiated cell fates, respectively. The mechanisms underlying these processes remain unknown. Here we show that among many pathways regulated by miR-294/302, the combinatorial suppression of epithelial-mesenchymal transition (EMT) and apoptotic pathways is sufficient in maintaining the self-renewal of ESCs. The silencing of ESC self-renewal by let-7 was accompanied by the upregulation of several EMT regulators and the induction of apoptosis. The ectopic activation of either EMT or apoptotic program is sufficient in silencing ESC self-renewal. However, only combined but not separate suppression of the two programs inhibited the silencing of ESC self-renewal by let-7 and several other differentiation-inducing miRNAs. These findings demonstrate that combined repression of the EMT and apoptotic pathways by miR-294/302 imposes a synergistic barrier to the silencing of ESC self-renewal, supporting a model whereby miRNAs regulate complicated cellular processes through synergistic repression of multiple targets or pathways.

The abnormal metabolism of cancer cells is a crucial feature of tumors and provides promising therapeutic targets for cancer treatments. Aerobic glycolysis in cancer cells, termed the Warburg effect, is a highlighted characteristic of cancer‑specific metabolism. However, the effect of glycolysis inhibition on hepatocarcinogenesis remains to be elucidated. In the present study, the effects of the glycolysis inhibitor 2‑deoxy‑D‑glucose (2‑DG) on the N‑diethylnitrosamine (DEN)‑induced rat hepatocarcinoma model and its underlying mechanisms were investigated. It was observed that 2‑DG significantly delayed hepatocarcinogenesis and effectively prolonged survival time in the DEN‑treated rats. The glycolysis inhibitor, 2‑DG prominently decreased cell proliferation and increased cell apoptosis in the DEN‑induced rat hepatoma and had no evident impact on the pericarcinomatous liver tissues. Further investigation revealed that 2‑DG resulted in a reduction of glycolysis products, the compensatory increase of hexokinase 2 expression and a decrease in 6‑phosphofructo‑2‑kinase, pyruvate kinase M2 and lactate dehydrogenase A expression in the hepatoma tissues. The inhibition of glycolysis further suppressed the tricarboxylic acid cycle, fatty acid and cholesterol biosynthesis and ATP production, while it promoted autophagic activation. In addition, the in vitro study demonstrated that hypoxia, an important factor in the tumor microenvironment, may assist in increasing 2‑DG‑induced inhibition of cell viability, cell cycle retardation and the decrease of colony formation ability in hepatoma cells. Taken together, the present results suggested that 2‑DG may inhibit hepatocarcinogenesis in the DEN‑treated rats via restricting cancer cell metabolism. This finding provides a promising measure in the prevention and treatment of hepatoma.

Levofloxacin, a fluoroquinolone, is a widely-used and effective antibiotic. However, various adverse side effects are associated with levofloxacin. The purpose of this study was to further explore the effects of levofloxacin on rat nucleus pulposus cells (NPCs). Inverted phase-contrast microscopy, flow cytometry and caspase-3 activity assays were used and revealed that serum deprivation induced apoptosis, which was markedly increased by levofloxacin in a dose-dependent manner. Simultaneously, levofloxacin decreased cell binding to type II collagen (COL2). Thus, levofloxacin-induced apoptosis exhibits characteristics of anoikis, the process by which cell death is triggered by separation from the extracellular matrix, which contains COL2. Furthermore, real-time quantitative RT-PCR was used to further confirm that levofloxacin downregulates COL2 expression in a dose-dependent manner. At last, western blot was used to find that levofloxacin increased the ratio of Bax/Bcl-2 and active caspase-3 in a dose-dependent manner. Levofloxacin therefore increases the effects of serum deprivation on anoikis by downregulating COL2 in rat NPCs in vitro via Bax/Bcl-2/caspase-3 pathway. This research provides a novel insight into the mechanisms of levofloxacin-induced toxicity and may potentially lead to a better understanding of the clinical effects of levofloxacin, especially in terms of intervertebral disc degeneration.

Intestinal ischemia-reperfusion (I/R) is a serious clinical dilemma with high morbidity and mortality. Remote organ damage, especially acute lung injury and liver injury are common complications that contribute to the high mortality rate. We previously demonstrated that activation of PKCβII is specifically involved in the primary injury of intestinal I/R. Considering the tissue-specific features of PKC activation, we hypothesized that some kind of PKC isoform may play important roles in the progression of secondary injury in the remote organ. Mice were studied in in vivo model of intestinal I/R. The activation of PKC isoforms were screened in the lung and liver. Interestingly, we found that PKCβII was also activated exclusively in the lung and liver after intestinal I/R. PKCβII suppression by a specific inhibitor, LY333531, significantly attenuated I/R-induced histologic damage, inflammatory cell infiltration, oxidative stress, and apoptosis in these organs, and also alleviated systemic inflammation. In addition, LY333531 markedly restrained p66shc activation, mitochondrial translocation, and binding to cytochrome-c. These resulted in the decrease of cytochrome-c release and caspase-3 cleavage, and an increase in glutathione and glutathione peroxidase. These data indicated that activated PKC isoform in the remote organ, specifically PKCβII, is the same as that in the intestine after intestinal I/R. PKCβII suppression protects against remote organ injury, which may be partially attributed to the p66shc-cytochrome-c axis. Combined with our previous study, the development of a specific inhibitor for prophylaxis against intestinal I/R is promising, to prevent multiple organ injury.

Cell death is closely related to autophagy under some circumstances; however, the effect of isoorientin (ISO) on autophagy and the interplay between apoptosis and autophagy in human hepatoblastoma cancer (HepG2) cells remains poorly understood. The present study showed that ISO induced autophagy, which was correlated with the formation of autophagic vacuoles and the overexpression of Beclin-1 and LC3-II. The autophagy inhibitor 3-methyladenine (3-MA) markedly inhibited apoptosis, and the apoptosis inhibitor ZVAD-fmk also decreased ISO-induced autophagy. In addition, the PI3K/Akt inhibitor LY294002 enhanced Beclin-1, LC3-II, and poly(ADP-ribose) polymerase (PARP) cleavage levels. Also, the reactive oxygen species (ROS) inhibitor N-acetyl-L-cysteine (NAC), the JNK inhibitor SP600125, and the p38 inhibitor SB203580 efficiently downregulated the levels of these proteins. Moreover, the p53 inhibitor pifithrin-α and the nuclear factor (NF)-κB inhibitor pyrrolidinedithiocarbamic acid (PDTC) clearly suppressed Beclin-1 and LC3-II and increased cytochrome c release, caspase-3 activation, and PARP cleavage. These results demonstrated for the first time that ISO simultaneously induced apoptosis and autophagy by ROS-related p53, PI3K/Akt, JNK, and p38 signaling pathways. Furthermore, ISO-induced apoptosis by activating the Fas receptor-mediated apoptotic pathway and suppressing the p53 and PI3K/Akt-dependent NF-κB signaling pathway, with the subsequent increase in the release of cytochrome c, caspase-3 activation, and PARP cleavage.

Paraspeckle protein 1 (PSPC1) was first identified as a structural protein of the subnuclear structure termed paraspeckle. However, the exact physiological functions of PSPC1 are still largely unknown. Previously, using a proteomic approach, we have shown that exposure to cisplatin can induce PSPC1 expression in HeLa cells, indicating the possible involvement for PSPC1 in the DNA damage response (DDR). In the current study, the role of PSPC1 in DDR was examined. First, it was found that cisplatin treatment could indeed induce the expression of PSPC1 protein. Abolishing PSPC1 expression by siRNA significantly inhibited cell growth, caused spontaneous cell death, and increased DNA damage. However, PSPC1 did not co-localize with γH2AX, 53BP1, or Rad51, indicating no direct involvement in DNA repair pathways mediated by these molecules. Interestingly, knockdown of PSPC1 disrupted the normal cell cycle distribution, with more cells entering the G2/M phase. Furthermore, while cisplatin induced G1/S arrest in HeLa cells, knockdown of PSPC1 caused cells to escape the G1/S checkpoint and enter mitosis, and resulted in more cell death. Taken together, these observations indicate a new role for PSPC1 in maintaining genome integrity during the DDR, particularly in the G1/S checkpoint.

Endogenously produced hydrogen sulfide (H2S) may have multiple functions in the brain including potent anti-inflammatory effects. Activated microglia can secrete various pro-inflammatory cytokines and neurotoxic mediators, which may contribute to hypoxic injuries in the developing brain. The aim of this study is to investigate the potential role of H2S in altering hypoxia-induced neurotoxicity via its anti-inflammatory actions as examined in vitro and in vivo models. Using the BV-2 microglial cell line, we found that sodium hydrosulfide (NaHS), a H2S donor, significantly inhibited hypoxia-induced microglial activation and suppressed subsequent pro-inflammatory factor release. In addition, treating murine primary cortical neurons with conditioned medium (CM) from hypoxia-stimulated microglia induced neuronal apoptosis, an effect that was reversed by CM treated with NaHS. Further, NaHS inhibited phosphorylation of the p65 subunit of NF-κB, phosphorylation of ERK and p38 but not JNK MAPK in these hypoxia-induced microglia. When administered in vivo to neonatal mice subjected to hypoxia, NaHS was found to attenuate neuron death, an effect that was associated with suppressed microglial activation, pro-inflammatory cytokines and NO levels. Taken together, H2S exerts neuroprotection against hypoxia-induced neurotoxicity through its anti-inflammatory effect in microglia. This effect appears to be attributable to inhibition of iNOS, NF-κB, ERK and p38 MAPK signaling pathways. Our results suggest a potential therapeutic application of H2S releasing drugs in hypoxic brain damage treatment.

Our group was the first one reporting that autophagy could be triggered by airborne fine particulate matter (PM) with a mean diameter of less than 2.5 μm (PM2.5) in human lung epithelial A549 cells, which could potentially lead to cell death. In the present study, we further explored the potential interactions between autophagy and apoptosis because it was well documented that PM2.5 could induce apoptosis in A549 cells. Much to our surprise, we found that PM2.5-exposure caused oxidative stress, resulting in activation of multiple cell death pathways in A549 cells, that is, the tumor necrosis factor-alpha (TNF-α)-induced pathway as evidenced by TNF-α secretion and activation of caspase-8 and -3, the intrinsic apoptosis pathway as evidenced by increased expression of pro-apoptotic protein Bax, decreased expression of anti-apoptotic protein Bcl-2, disruption of mitochondrial membrane potential, and activation of caspase-9 and -3, and autophagy as evidenced by an increased number of double-membrane vesicles, accompanied by increases of conversion and punctuation of microtubule-associated proteins light chain 3 (LC3) and expression of Beclin 1. It appears that reactive oxygen species (ROS) function as signaling molecules for all the three pathways because pretreatment with N-acetylcysteine, a scavenger of ROS, almost completely abolished TNF-α secretion and significantly reduced the number of apoptotic and autophagic cells. In another aspect, inhibiting autophagy with 3-methyladenine, a specific autophagy inhibitor, enhanced PM2.5-induced apoptosis and cytotoxicity. Intriguingly, neutralization of TNF-α with an anti-TNF-α special antibody not only abolished activation of caspase-8, but also drastically reduced LC3-II conversion. Thus, the present study has provided novel insights into the mechanism of cytotoxicity and even pathogenesis of diseases associated with PM2.5 exposure.

Apoptosis is a major mode of cell death occurring during ischemia-reperfusion (I/R) induced injury. The p66(Shc) adaptor protein, which is mediated by PKCβ, has an essential role in apoptosis under oxidative stress. This study aimed to investigate the role of PKCβ2/p66(Shc) pathway in intestinal I/R injury. In vivo, ischemia was induced by superior mesenteric artery occlusion in mice. Ruboxistaurin (PKCβ inhibitor) or normal saline was administered before ischemia. Then blood and gut tissues were collected after reperfusion for various measurements. In vitro, Caco-2 cells were challenged with hypoxia-reoxygenation (H/R) to simulate intestinal I/R. Translocation and activation of PKCβ2 were markedly induced in the I/R intestine. Ruboxistaurin significantly attenuated gut damage and decreased the serum levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Pharmacological blockade of PKCβ2 suppressed p66(Shc) overexpression and phosphorylation in the I/R intestine. Gene knockdown of PKCβ2 via small interfering RNA (siRNA) inhibited H/R-induced p66(Shc) overexpression and phosphorylation in Caco-2 cells. Phorbol 12-myristate 13-acetate (PMA), which stimulates PKCs, induced p66(Shc) phosphorylation and this was inhibited by ruboxistaurin and PKCβ2 siRNA. Ruboxistaurin attenuated gut oxidative stress after I/R by suppressing the decreased expression of manganese superoxide dismutase (MnSOD), the exhaustion of the glutathione (GSH) system, and the overproduction of malondialdehyde (MDA). As a consequence, ruboxistaurin inhibited intestinal mucosa apoptosis after I/R. Therefore, PKCβ2 inhibition protects mice from gut I/R injury by suppressing the adaptor p66(Shc)-mediated oxidative stress and subsequent apoptosis. This may represent a novel therapeutic approach for the prevention of intestinal I/R injury.

It has been documented in in vitro studies that zinc oxide nanoparticles (ZnO NPs) are capable of inducing oxidative stress, which plays a crucial role in ZnO NP-mediated apoptosis. However, the underlying molecular mechanism of apoptosis in neurocytes induced by ZnO NP exposure was not fully elucidated. In this study, we investigated the potential mechanisms of apoptosis provoked by ZnO NPs in cultured primary astrocytes by exploring the molecular signaling pathways triggered after ZnO NP exposure. ZnO NP exposure was found to reduce cell viability in MTT assays, increase lactate dehydrogenase (LDH) release, stimulate intracellular reactive oxygen species (ROS) generation, and elicit caspase-3 activation in a dose- and time-dependent manner. Apoptosis occurred after ZnO NP exposure as evidenced by nuclear condensation and poly(ADP-ribose) polymerase-1 (PARP) cleavage. A decrease in mitochondrial membrane potential (MMP) with a concomitant increase in the expression of Bax/Bcl-2 ratio suggested that the mitochondria also mediated the pathway involved in ZnO NP-induced apoptosis. In addition, exposure of the cultured cells to ZnO NPs led to phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-related kinase (ERK), and p38 mitogen-activated protein kinase (p38 MAPK). Moreover, JNK inhibitor (SP600125) significantly reduced ZnO NP-induced cleaved PARP and cleaved caspase-3 expression, but not ERK inhibitor (U0126) or p38 MAPK inhibitor (SB203580), indicating that JNK signaling pathway is involved in ZnO NP-induced apoptosis in primary astrocytes.

Previous research demonstrated that glutamate induces neuronal injury partially by increasing intracellular Ca(2+) concentrations ([Ca(2+)]i), and inducing oxidative stress, leading to a neurodegenerative disorder. However, the mechanism of glutamate-induced injury remains elusive. Gastrodin, a major active component of the traditional herbal agent Gastrodia elata (GE) Blume, has been recognized as a potential neuroprotective drug. In the current study, a classical injury model based on glutamate-induced cell death of rat pheochromocytoma (PC12) cells was used to investigate the neuroprotective effect of gastrodin, and its potential mechanisms involved. In this paper, the presence of gastrodin inhibits glutamate-induced oxidative stress as measured by the formation of reactive oxygen species (ROS), the level of malondialdehyde (MDA), mitochondrial membrane potential (MMP), and superoxide dismutase (SOD); gastrodin also prevents glutamate-induced [Ca(2+)]i influx, blocks the activation of the calmodulin-dependent kinase II (CaMKII) and the apoptosis signaling-regulating kinase-1 (ASK-1), inhibits phosphorylation of p38 mitogen-activated kinase (MAPK). Additionally, gastrodin blocked the expression of p53 phosphorylation, caspase-3 and cytochrome C, reduced bax/bcl-2 ratio induced by glutamate in PC12 cells. All these findings indicate that gastrodin protects PC12 cells from the apoptosis induced by glutamate through a new mechanism of the CaMKII/ASK-1/p38 MAPK/p53-signaling pathway.

20(S)-Ginsenoside Rh2 (GRh2) and ginsenoside Rg3 (GRg3) are members of the protopanaxadiol family and have been investigated for possible chemopreventive activity. This study explored the biological and apoptotic mechanisms induced by 20(S)-GRh2 in human acute leukaemia line-Reh cells. Reh cells were treated with different concentration of 20(S)-GRh2 in vitro. Cell viability was determined by Cell Counting Kit-8 and Annexin V/7-AAD assays. Mitochondrial membrane potential (MMP) was examined through JC-1 staining. Activation of caspases associated with the mitochondria-mediated apoptosis pathway was determined by Western blot. We observed that survival of Reh cells decreased after exposure to 20(S)-GRh2 in a concentration-dependent manner. Moreover, 20(S)-GRh2 can induce mitochondria depolarization of Reh cells as evident in the shift in JC-1 fluorescence from red to green. In addition, 20(S)-GRh2 induced the release of mitochondrial cytochrome c and activation of caspase-9 and caspase-3 in Reh cells. These results indicate that 20(S)-GRh2 could induce apoptosis through the mitochondrial pathway, demonstrating its potential as a chemotherapeutic agent for leukaemia therapy.

The collagen type II alpha 1 (COL2A1) mutation causes severe skeletal malformations, but the pathogenic mechanisms of how this occurs are unclear. To understand how this may happen, a col2a1 p.Gly1170Ser mutated mouse model was constructed and in homozygotes, the chondrodysplasia phenotype was observed. Misfolded procollagen was largely synthesized and retained in dilated endoplasmic reticulum and the endoplasmic reticulum stress (ERS)-unfolded protein response (UPR)-apoptosis cascade was activated. Apoptosis occurred prior to hypertrophy, prevented the formation of a hypertrophic zone, disrupted normal chondrogenic signaling pathways, and eventually caused chondrodysplasia. Heterozygotes had normal phenotypes and endoplasmic reticulum stress intensity was limited with no abnormal apoptosis detected. Our results suggest that earlier chondrocyte death was related to the ERS-UPR-apoptosis cascade and that this was the chief cause of chondrodysplaia. The col2a1 p.Gly1170Ser mutated mouse model offered a novel connection between misfolded collagen and skeletal malformation. Further investigation of this mouse mutant model can help us understand mechanisms of type II collagenopathies.

The present study aims to investigate the pharmacological effect of the exopolysaccharides from Aphanothece halophytica GR02 (EPSAH) on the HeLa human cervical cancer cell line. HeLa cells were cultured in RPMI-1640-10% FBS medium containing with or without different concentrations of EPSAH. Cell viability was assessed by methylthiazol tetrazolium (MTT) assay. Cell apoptosis was elevated with Wright-Giemsa staining, AO/EB double staining, and DNA fragmentation assay. Apoptosis-associated molecules from cultured HeLa cells were quantified using Western blot analysis. Our results suggest that EPASH induces apoptosis in HeLa cells by targeting a master unfolded protein response (UPR) regulator Grp78. Grp78 further promotes the expression of CHOP and downregulates expression of survivin, which leads to activate mitochondria-mediated downstream molecules and p53-survivin pathway, resulting in caspase-3 activation and causing apoptosis. These findings provide important clues for further evaluating the potential potency of EPSAH for use in cancer therapy.

Metal nanomaterial could effectively decrease tumour resistance to anti-cancer drugs. In this paper, we have explored the synergistic effect and mechanisms of zinc oxide nanoparticles (ZnO Nps) and isoorientin (ISO) on cytotoxicity in human hepatoma (HepG2) cells. The results showed that ZnO Nps could exert dose- and time-dependent cytotoxicity in HepG2 cells, and the combining treatment resulted in a greater cytotoxicity than single treatment. ZnO Nps could synergistically potentiate ISO to induce apoptosis through resulting in mitochondrial dysfunction, inhibiting the phosphorylation of Akt and ERK1/2, and enhancing the phosphorylation of JNK and P38. Additionally, ZnO Nps were uptaked by cells through endocytic pathway and it enhanced the cellular uptake of ISO, while no significant injury was found in normal liver cells after the combined treatment. These results suggest that the combination of metal nanoparticle with anti-cancer drugs may provide a promising alternative for novel cancer treatments.

Verapamil (Ver), an inhibitor of the multidrug resistance gene product, has been proved to be a promising combination partner with other anti-cancer agents including proteasome inhibitor bortezomib. Gambogic acid (GA) has been approved for Phase II clinical trials in cancer therapy in China. We have most recently reported that GA is a potent proteasome inhibitor, with anticancer efficiency comparable to bortezomib but much less toxicity. In the current study we investigated whether Ver can enhance the cytotoxicity of GA. We report that (i) the combination of Ver and GA results in synergistic cytotoxic effect and cell death induction in HepG2 and K562 cancer cell lines; (ii) a combinational treatment with Ver and GA induces caspase activation, endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) production; (iii) caspase inhibitor z-VAD blocks GA+Ver-induced apoptosis but not proteasome inhibition; (iv) cysteine-containing compound N-acetylcysteine (NAC) prevents GA+Ver-induced poly(ADP-ribose) polymerase cleavage and proteasome inhibition. These results demonstrate that Ver accelerates GA-induced cytotoxicity via enhancing proteasome inhibition and ROS production. These findings indicate that the natural product GA is a valuable candidate that can be used in combination with Ver, thus representing a compelling anticancer strategy.

The proteasome inhibitor-based combinational therapy has been reported to be an efficient cancer treatment. Our recent studies demonstrated that the natural compound gambogic acid (GA) is a tissue-specific proteasome inhibitor, comparable to bortezomib (Bor), and sensitizes malignant cells to the proteasome inhibitor MG132/MG262 both in vitro and in vivo. The aim of this study was to further extend our investigation by combining GA with the clinically used proteasome inhibitor Bor to test their combined efficacy against human hepatoma HepG2 and mouse hepatoma H22 cells. GA and Bor synergistically induced cytotoxicity and cell death in human HepG2 and mouse H22 cells, and accelerated proteasome inhibition, endoplasmic reticulum (ER) stress and caspase activation in HepG2 cancer cells. However, unexpectedly, GA did not enhance or even antagonized Bor-induced tumor growth inhibition in H22 allograft and HepG2 xenograft tumor models. These findings demonstrated that GA increased Bor activity in vitro but limited the efficacy of Bor in vivo. We suggest that the combination of GA and Bor be avoided when administering these drugs to patients.

Necroptosis was recently discovered as one form of programmed cell death (PCD) and could be specifically inhibited by necrostatin-1. The aim of this study was to examine the effect of necrostatin-1 on brain injury and investigate the role of necrostatin-1 on the other two types PCD (apoptosis and autophagic cell death) in a mouse intracerebral hemorrhage (ICH) model. Male ICR mice received an infusion of type IV collagenase to induce ICH or saline as control into the left striatum. In the presence of vehicle, 3-MA, zVAD, and necrostatin-1 were pretreated with a single intracerebroventricular (i.c.v.) injection in the ipsilateral ventricle 15 min before ICH, respectively. Compared with vehicle groups, necrostatin-1 treatment significantly reduced injury volume and propidium iodide-positive cells at 24 and 72 h after ICH. Immunoblotting analysis showed that necrostatin-1 treatment suppressed autophagic-associated proteins (LC3-II, Beclin-1) and maintained p62 at normal level at 24 and 72 h after ICH. In addition, necrostatin-1 treatment enhanced the protein level of Bcl-2 and decreased the protein level of cleaved caspase-3 and the Beclin-1/Bcl-2 ratio at 24 and 72 h after ICH. Moreover, both 3-MA and necrostatin-1 treatment could suppress cleaved caspase-3 and LC3-II production, whereas zVAD treatment could inhibit caspase-3 cleavage but increased LC3-II protein levels at 72 h after ICH. Taken together, the data demonstrated for the first time that the specific inhibitor necrostatin-1 suppressed apoptosis and autophagy to exert these neuroprotective effects after ICH and that there existed a cross-talk among necroptosis, apoptosis, and autophagy after ICH.

3-Oxo-29-noroleana-1,9(11),12-trien-2,20-dicarbonitrile (ONTD) is a novel synthetic derivative of glycyrrhetinic acid (GA), which has the ability to inhibit the proliferation of human hepatocellular carcinoma (HCC) cells. However, the mechanisms by which ONTD exerts its inhibitory effects remain elusive. The present study was conducted to investigate the cytotoxicity of ONTD in Bel-7402 cells and its molecular mechanisms. We found that ONTD depleted intracellular GSH, increased the level of ROS, and consequently induced mitochondrial permeability transition (MPT) leading to the release of apoptosis-inducing factor (AIF) and cytochrome c (Cyt c) to the cytosol. Mitochondrial alteration and subsequent apoptotic cell death in ONTD-treated Bel-7402 cells could be blocked by addition of exogenous antioxidants N-acetylcystein (NAC), GSH and the MTP inhibitor cyclosporin A (CsA). In addition, ONTD activated the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinases (MAPK) but not extracellular signal-regulated protein kinases (ERK 1/2). When the cells were exposed to SP600125 (a JNK inhibitor) and SB203580 (a p38 inhibitor), the deregulation of the expression of apoptotic proteins was attenuated. Furthermore, 40 mg/kg ONTD significantly reduced tumor weight (-70.62%, p<0.01) in the H22 tumor-bearing mouse model in vivo. Taken together, these findings provide the first experimental evidence supporting that ONTD could induce apoptosis of Bel-7402 cells via MAPK-mediated mitochondrial pathway and ONTD has the potential to be developed as a therapeutic agent for the treatment of HCC.

Salvianolic acid A (SalA) is a phenolic carboxylic acid derivative extracted from Salvia miltiorrhiza. It has many biological and pharmaceutical activities. The purpose of this study was to investigate the effect of SalA on concanavalin A (ConA)-induced acute hepatic injury in Kunming mice and to explore the role of SIRT1 in such an effect. The results showed that in vivo pretreatment with SalA significantly reduced ConA-induced elevation in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and decreased levels of the hepatotoxic cytokines such as interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α). Moreover, the SalA pretreatment ameliorated the increases in NF-κB and in cleaved caspase-3 caused by ConA exposure. Whereas, the pretreatment completely reversed expression of the B-cell lymphoma-extra large (Bcl-xL). More importantly, the SalA pretreatment significantly increased the expression of SIRT1, a NAD(+)-dependent deacetylase, which was known to attenuate acute hypoxia damage and metabolic liver diseases. In our study, the increase in SIRT1 was closely associated with down-regulation of the p66 isoform (p66shc) of growth factor adapter Shc at both protein and mRNA levels. In HepG2 cell culture, SalA pretreatment increased SIRT1 expression in a time and dose-dependent manner and such an increase was abrogated by siRNA knockdown of SIRT1. Additionally, inhibition of SIRT1 significantly reversed the decreased expression of p66shc, and attenuated SalA-induced p66shc down-regulation. Collectively, the present study indicated that SalA may be a potent activator of SIRT and that SalA can alleviate ConA-induced hepatitis through SIRT1-mediated repression of the p66shc pathway.

Perihematomal brain edema formation and consequent cell death contribute to second brain injury resulting in severe neurological deficits and sometimes delayed fatality after intracerebral hemorrhage (ICH). [Gly14]-Humanin (HNG), a variant of Humanin (HN) in which the 14th amino acid serine is replaced with glycine, reduced Alzheimer's disease-relevant insults and improved neurological deficits in an ischemia stroke model. In the study, we aimed to evaluate whether HNG posttreatment attenuated early brain injury after ICH and whether the protective effect was associated with regulation of apoptosis via phosphatidylinositol 3-kinase (PI3K)-Akt/GSK-3β signaling. Male ICR mice were subjected to infusion of Type IV collagenase (to induce ICH) of saline (for shams) into the left striatum. ICH animals received vehicle, HNG (1 or 2.5 μg in 100 μl saline) administration intraperitoneally 1h post injury. Compared with vehicle, HNG-2.5 μg treatment improved neurological outcome and reduced brain edema at 24 and 72 h after surgery (P<0.05), but wortmannin (15 μg/kg, 90 min before HNG-2.5 μg, intravenously) obliterated the effect. HNG-2.5 μg also reduced cell insults and injury volume at 24 and 72 h after surgery (P<0.05, vs. vehicle). Furthermore, HNG-2.5 μg treatment increased p-Akt and Bcl-2 and decreased p-GSK-3β, cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase expressions in the ipsilateral hemisphere (P<0.05, vs. vehicle), however, the effect was reversed by wortmannin. In conclusion, HNG treatment improved functional and morphological outcomes after experimental ICH in mice and the protective effect was associated with suppressing apoptosis through PI3K-Akt/GSK-3β signaling pathway.

Graphene oxide (GO) has attracted intensive interest in the biomedical field in recent years. We investigate whether the use of functional graphene oxide as an efficient delivery system for delivering specific molecular antitumor therapeutics in vivo could achieve a more excellent antitumor effect. Constitutive activation of signal transducer and activator of transcription 3 (Stat3) promotes survival in a wide spectrum of human cancers. In this paper, we study the in vivo behavior of graphene oxide chemically functionalized with polyethylenimine and polyethylene glycol (GO-PEI-PEG) as a plasmid-based Stat3-specific small interfering RNA (siRNA) carrier in mouse malignant melanoma. The in vivo results indicate significant regression in tumor growth and tumor weight after plasmid-based Stat3 siRNA delivered by GO-PEI-PEG treatment. Moreover, there was no significant side effect from GO-PEI-PEG treatment according to histological examination and blood chemistry analysis in mice. Thus, our work is the first success of using GO-PEI-PEG as a promising carrier for plasmid Stat3 siRNA delivery and down-regulation of Stat3 by a polymer-mediated vehicle and suggests the great promise of graphene in biomedical applications such as cancer treatment.

Isoorientin (ISO) (CAS RN: 4261-42-1) is a flavonoid compound that can be extracted from several plant species, such as Phyllostachys pubescens, Patrinia, and Drosophyllum lusitanicum. ISO is able to induce apoptosis through mitochondrial dysfunction and inhibition of PI3K/Akt signaling pathway in HepG2 cells, however, the effects of ISO on MAPK signaling pathways remain unknown. The present study investigated the effects of ISO on this pathway, and the roles of MAPK kinases on mitochondrial-mediated apoptosis in HepG2 cells. The results showed that ISO induced cell death in a dose- and time-dependent manner, and induction apoptosis is main cause for ISO-induced cytotoxicity in HepG2 cells. ISO significantly inhibited the levels of ERK1/2 kinase and increased the expression of JNK and p38 kinases. Furthermore, U0126 (an ERK1/2 inhibitor) significantly enhanced the ISO-induced the Bax/Bcl-2 ratio, the release of cytochrome c to the cytosol fraction, and the levels of cleaved caspase-3. While SP600125 (a JNK inhibitor) and SB203580 (a p38 inhibitor) markedly prevented the expression of these proteins induced by ISO. Furthermore, the ROS inhibitor (NAC) notably promoted the inhibited effect of ISO on the ERK1/2 kinase. NAC also suppressed the p-JNK and p-p38, but failed to reverse the effects of ISO. These results demonstrated for the first time that ISO induces apoptosis in HepG2 cells through inactivating ERK1/2 kinase and activating JNK and p38 kinases, and ROS stimulated by ISO is able to activate the MAPK singaling pathway as the upstream signaling molecules. Initiating event of the mitochondrial-mediated apoptosis induced by ISO is MAPK signals.

It is well established that both hematoporphyrin monomethyl ether-sonodynamic therapy (HMME-SDT) and doxorubicin (DOX) can induce cell apoptosis but each alone has its own limitations. To date, the combined effects of HMME-SDT and DOX on inducing cell apoptosis are little known and the mechanism for the combined effects remains poorly understood. In the present study, we reported the synergistic effects of HMME-SDT and DOX on inhibiting the proliferation of human cholangiocarcinoma QBC939 cells and investigated the mechanism of this synergy. The data from MTT assay, flow cytometer, Hoechst staining and cell arrest analysis showed that the combination of HMME-SDT and DOX exhibited higher inhibiting effects on proliferation of QBC939 cells than the sole application of HMME-SDT or DOX. In addition, the synergistic effects were shown to result from the DNA damage as demonstrated by single cell gel electrophoresis and DNA fragmentation. Furthermore, the expression of p53, Fas, Bax and activated caspase-3 protein was significantly upregulated in cells treated with HMME-SDT and DOX, whereas Bcl-2 protein was downregulated. Taken together, our data suggested that the application of HMME-SDT combined with DOX had better inhibiting effects on QBC939 cells and the effects were caused mainly by DNA damage.

Curcumin (diferuloylmethane) is a natural polyphenol product of the plant Curcuma longa and has a diversity of antitumor activities. T63, a new 4-arylidene curcumin analogue, was reported to inhibit proliferation of lung cancer cells. However, its precise molecular antitumor mechanisms have not been well elucidated. Here, we showed that T63 could significantly inhibit the proliferation of A549 and H460 human lung cell lines via induction of G0/G1 cell cycle arrest and apoptosis. We found that the reactive oxygen species (ROS)-activated FOXO3a cascade plays a central role in T63-induced cell proliferation inhibition. Mechanistically, enhancement of ROS production by T63 induced FOXO3a expression and nuclear translocation through activation of p38MAPK and inhibition of AKT, subsequently elevating the expression of FOXO3a target genes, including p21, p27, and Bim, and then increased the levels of activated caspase-3 and decreased the levels of cyclin D1. Moreover, the antioxidant N-acetylcysteine markedly blocked the above effects, and small interfering RNA-mediated knockdown of FOXO3a also significantly decreased T63-induced cell cycle arrest and apoptosis. In vivo experiments showed that T63 significantly suppressed the growth of A549 lung cancer xenograft tumors, associated with proliferation suppression and apoptosis induction in tumor tissues, without inducing any notable major organ-related toxicity. These data indicated that the novel curcumin analogue T63 is a potent antitumor agent that induces cell cycle arrest and apoptosis and has significant therapeutic potential for lung cancer.

Herbacetin (HER) is a natural flavonoid compound that can be extracted from Ramose Scouring Rush Herb, and its biological and pharmacological activities lack of corresponding attention. In this study, the apoptotic effect of HER against the human hepatoma cell line (HepG2) was investigated. The results showed that HepG2 cells apoptosis occurred in a dose-dependent manner within 48h incubated with HER, which was confirmed by DNA fragmentation, nuclear shrinkage, and poly (ADP-ribose) polymerase (PARP) cleavage. HER at 25-100μM induced a mitochondria-dependent apoptotic pathway associated with Bcl-2/Bax ratio decrease, mitochondrial membrane potential (ΔΨ) collapse, cytochrome c release, and caspase-3 activation. Increasing expression of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) was also observed in HER-treated cells. Furthermore, the addition of a ROS inhibitor (N-Acetyl-l-cysteine, NAC) significantly attenuated the apoptosis induced by HER and also blocked the expression of PGC-1α protein. Additionally, HER effectively inhibited the phosphorylation of Akt and the phosphatidylinositol-3 kinase (PI3K) inhibitor LY294002 increased the inhibition effect of HER on Akt phosphorylation. These findings provide evidences that HER induces HepG2 apoptosis in a ROS-mediated mitochondria-dependent manner that correlate with the inactivation of the PI3K/Akt pathway.

Angiogenesis inhibitors have long been considered desirable anticancer agents. However, it was found that many tumors could develop resistance to antiangiogenesis inhibitors. Antiangiogenic therapy results in metabolic stress. Autophagy is an important survival mechanism in cancer cells under metabolic stress; however, it remains unknown if autophagy contributes to antiangiogenesis resistance. In this study, we reported that bevacizumab treatment reduced the development of new blood vessels and inhibited cell growth in xenografts of hepatocellular carcinoma (HCC) tumors. Bevacizumab treatment also upregulated expression of the autophagy-related genes (Beclin1 and LC3) and increased autophagosome formation. Our in vitro studies demonstrated that autophagy inhibition significantly increased apoptosis of HCC cells during nutrient starvation or hypoxia. In addition, the combined treatment of an autophagy inhibitor and bevacizumab markedly inhibited the tumor growth of HCC xenografts, led to enhanced apoptosis, and impaired the proliferation of tumor cells compared with treatment with either drug alone. Furthermore, autophagy inhibition led to enhanced reactive oxygen species (ROS) generation in HCC cells exposed to nutrient starvation or hypoxia in vitro and increased DNA oxidative damage in vivo. Antioxidants reduced nutrient starvation or the hypoxia-induced cell death of HCC cells after autophagy inhibition. Our results suggest that autophagy modulates ROS generation and contributes to cell survival under metabolic stress. Therefore, autophagy inhibition may be a novel way of increasing the efficicacy of antiangiogenic agents in the treatment of HCC.

Apoptosis of lens epithelial cell (LEC) plays an important role in cataract formation, and its prevention may be one of the therapeutic strategies in treating cataract. This study used human lens epithelial cell (hLEC) line SRA01/04 to investigate the protective effect and mechanism of phycocyanin on glactose-induced apoptosis in hLEC. hLECs were cultured in D/F(12)-10% FBS medium containing 125mM d-galactose with or without phycocyanin. Cell viability was assessed by methylthiazol tetrazolium (MTT) assay. Cell apoptosis was elevated with Wright-Giemsa staining, AO/EB double staining, and DNA fragmentation assay. Mitochondrial apoptosis-associated molecules and unfolded protein response-associated molecules from cultured SRA01/04 cells were quantified using protein blot analysis. The results demonstrated that phycocyanin suppressed SRA01/04 cells' morphologic changes and apoptosis induced by d-galactose, inhibited the expression and activation of caspase 3, alternated the Bax/Bcl-2 ratio, and down-regulated the level of p53, GRP78, and CHOP in d-galactose-treated SRA01/04 cells. These results suggest that phycocyanin might suppress d-galactose-induced hLEC apoptosis through two pathways: mitochondrial pathway, involving p53 and Bcl-2 family protein expression, and unfolded protein response pathway, involving GRP78 and CHOP expression.

MicroRNAs, a class of small and non-encoding RNAs that transcriptionally or post-transcriptionally modulate the expression of their target genes, has been implicated as critical regulatory molecules in many cardiovascular diseases, including ischemia/reperfusion induced cardiac injury. Here, we report microRNA-145, a tumor suppressor miRNA, can protect cardiomyocytes from hydrogen peroxide H₂O₂-induced apoptosis through targeting the mitochondrial pathway. Quantitative real-time PCR (qPCR) demonstrated that the expression of miR-145 in either ischemia/reperfused mice myocardial tissues or H₂O₂-treated neonatal rat ventricle myocytes (NRVMs) was markedly down-regulated. Over-expression of miR-145 significantly inhibited the H₂O₂-induced cellular apoptosis, ROS production, mitochondrial structure disruption as well as the activation of key signaling proteins in mitochondrial apoptotic pathway. These protective effects of miR-145 were abrogated by over-expression of Bnip3, an initiation factor of the mitochondrial apoptotic pathway in cardiomyocytes. Finally, we utilized both luciferase reporter assay and western blot analysis to identify Bnip3 as a direct target of miR-145. Our results suggest miR-145 plays an important role in regulating mitochondrial apoptotic pathway in heart challenged with oxidative stress. MiR-145 may represent a potential therapeutic target for treatment of oxidative stress-associated cardiovascular diseases, such as myocardial ischemia/reperfusion injury.

Isoorientin (ISO) is a flavonoid compound that can be extracted from several plant species, such as Phyllostachys pubescens, Patrinia, and Drosophyllum lusitanicum; however, its biological activity remains poorly understood. The present study investigated the effects and putative mechanism of apoptosis induced by ISO in human hepatoblastoma cancer (HepG2) cells. The results showed that ISO induced cell death in a dose-dependent manner in HepG2 cells, but no toxicity in human liver cells (HL-7702) and buffalo rat liver cells (BRL-3A) treated with ISO at the indicated concentrations. ISO-induced cell death included apoptosis which characterized by the appearance of nuclear shrinkage, the cleavage of poly (ADP-ribose) polymerase (PARP) and DNA fragmentation. ISO significantly (p<0.01) increased the Bax/Bcl-2 ratio, disrupted the mitochondrial membrane potential (MMP), increased the release of cytochrome c, activated caspase-3, and enhanced intracellular levels of reactive oxygen species (ROS) and nitric oxide (NO). In addition, ISO effectively inhibited the phosphorylation of Akt and increased FoxO4 expression. The PI3K/Akt inhibitor LY294002 enhanced the apoptosis-inducing effect of ISO. However, LY294002 markedly quenched ROS and NO generation and diminished the protein expression of heme peroxidase enzyme (HO-1) and inducible nitric oxide synthase (iNOS). Furthermore, the addition of a ROS inhibitor (N-acetyl cysteine, NAC) or iNOS inhibitor (N-[3-(aminomethyl) benzyl] acetamidine, dihydrochloride, 1400W) significantly diminished the apoptosis induced by ISO and also blocked the phosphorylation of Akt. These results demonstrated for the first time that ISO induces apoptosis in HepG2 cells and indicate that this apoptosis might be mediated through mitochondrial dysfunction and PI3K/Akt signaling pathway, and has no toxicity in normal liver cells, suggesting that ISO may have good potential as a therapeutic and chemopreventive agent for liver cancer.

O(2)-(2,4-dinitro-5-{[2-(12-en-28-β-D- galactopyranosyl-oleanolate-3-yl) -oxy-2-oxoethyl]amino}phenyl)1-(N-hydroxyethylmethylamino)diazen-1-ium-1,2- diolate (NG), a novel PABA/NO-based derivative of oleanolic acid (OA), has been found to show potent antitumor activity both in vivo and in vitro. In the present study, NG could significantly reduce tumor volume and weight in the H22 solid tumor mouse model. Meanwhile, NG showed selective effects on the HepG2 cells including NO generation, cytotoxic effect and apoptosis, which were prevented by hemoglobin (NO scavenger). Moreover, NG-induced apoptosis of HepG2 cells was characteristic of intracellular reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential (Δψm) and enhanced Bax-to-Bcl-2 ratio. The release of apoptotic inducing factor (AIF) and cytochrome c (Cyt c) from mitochondria and the activation of caspase-3, 9 were also detected, indicating that NG may induce apoptosis through a mitochondrial-mediated pathway. Simultaneously, NG treatment could lead to the activation of the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 MAPK but not ERK1/2. Treatment with SP600125 (an inhibitor of JNK) and SB203580 (an inhibitor of p38) prior to NG was found to reverse NG-induced apoptosis. Moreover, it was found that antioxidant N-acetylcysteine (NAC) blocked the induction of apoptosis and partly reversed the activation of JNK and p38, up-regulation of Bax, down-regulation of Bcl-2 and the activation of caspase-3 in NG-treated cells. Taking together, these findings suggest that NO can be released from NG, which induces apoptosis through a ROS/MAPK-mediated mitochondrial pathway.

We investigate the cytoprotective effects and the molecular mechanism of genistein in oxidative stress-induced injury using an endothelial cell line (EA.hy926). An oxidative stress model was established by incubating endothelial cells with H₂O₂. According to the present results, genistein pretreatment protected endothelial cells against H₂O₂-induced decreases in cell viability and increases in apoptosis. Genistein also prevented the inhibition of B-cell lymphoma 2 and the activation of caspase-3 induced by H₂O₂. Genistein increased superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels and attenuated the decrease in these antioxidants during oxidative stress. We also found that genistein induced the promoter activity of both nuclear factor erythroid 2-related factor 2 (Nrf2) and PPARγ. Additionally, genistein induced the nuclear translocation of Nrf2 and PPARγ. While genistein caused the up-regulation of both Nrf2 and PPARγ, it also activated and up-regulated the protein expression and transcription of a downstream protein, haem oxygenase-1 (HO-1). Moreover, the use of Nrf2 small interfering RNA transfection and HO-1- or PPARγ-specific antagonists (Znpp and GW9662, respectively) blocked the protective effects of genistein on endothelial cell viability during oxidative stress. Therefore, we conclude that oxidative stress-induced endothelial cell injury can be attenuated by treatment with genistein, which functions via the regulation of the Nrf2 and PPARγ signalling pathway. Additionally, the endogenous antioxidants SOD, CAT and GSH appear to play a role in the antioxidant activity of genistein. The present findings suggest that the beneficial effects of genistein involving the activation of cytoprotective antioxidant genes may represent a novel strategy in the prevention and treatment of cardiovascular endothelial damage.

Oxaliplatin is one of the agents used against colorectal cancer. Using PEG-liposome encapsulated oxaliplatin may enhance the accumulation of drugs in tumor cells, inducing apoptosis. However, the mechanism of action of PEG-liposome encapsulated oxaliplatin remains unclear. SW480 human colorectal cancer cells were treated with empty PEG-liposomes, free oxaliplatin or PEG-liposomal oxaliplatin. Cell cycle and apoptosis were assessed using fluorescence confocal microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-fluorescein nick-end-labeling (TUNEL). Western blotting was used to analyze the expression of pro-apoptotic, anti-apoptotic and cyclin proteins. We found that PEG-liposomal oxaliplatin induced a stronger apoptotic response than empty PEG-liposomes or free oxaliplatin. Moreover, expression of Cyclin D1 increased, whereas expression of Cyclin A decreased after treatment with PEG-liposomal oxaliplatin. Furthermore, the cell cycle was arrested in the G1 phase. The results presented here indicate that PEG-liposome entrapment of oxaliplatin enhances the anticancer potency of the chemotherapeutic agent. The effect of PEG-liposomal oxaliplatin on apoptosis of SW480 human colorectal cancer cells may be through regulation of expression of Cyclin A or Cyclin D1, as well as pro-apoptotic and anti-apoptotic proteins.

Baohuoside I (also known as Icariside II) is a flavonoid isolated from Epimedium koreanum Nakai. Although Baohuoside I exhibits anti-inflammatory and anti-cancer activities, its molecular targets/pathways in human lung cancer cells are poorly understood. Therefore, in the present study, we investigated the usefulness of Baohuoside I as a potential apoptosis-inducing cytotoxic agent using human adenocarcinoma alveolar basal epithelial A549 cells as in vitro model. The apoptosis induced by Baohuoside I in A549 cells was confirmed by annexin V/propidium iodide double staining, cell cycle analysis and dUTP nick end labeling. Further research revealed that Baohuoside I accelerated apoptosis through the mitochondrial apoptotic pathway, involving the increment of BAX/Bcl-2 ratio, dissipation of mitochondrial membrane potential, transposition of cytochrome c, caspase 3 and caspase 9 activation, degradation of poly (ADP-ribose) polymerase and the over-production of reactive oxygen species (ROS). A pan-caspase inhibitor, Z-VAD-FMK, only partially prevented apoptosis induced by Baohuoside I, while NAC, a scavenger of ROS, diminished its effect more potently. In addition, the apoptotic effect of Baohuoside I was dependent on the activation of ROS downstream effectors, JNK and p38(MAPK), which could be almost abrogated by using inhibitors SB203580 (an inhibitor of p38(MAPK)) and SP600125 (an inhibitor of JNK). These findings suggested that Baohuoside I might exert its cytotoxic effect via the ROS/MAPK pathway.

Emerging evidence has indicated microRNAs are involved in tumor development and progression, acting as tumor suppressors or oncogenes. Here we report that miR-409-3p was significantly downregulated in gastric cancer (GC) cell lines and tissues. Overexpression of miR-409-3p in SGC-7901 gastric cancer cells dramatically suppressed cell proliferation and induced cell apoptosis both in vitro and in vivo. Furthermore, we demonstrate that the transcriptional regulator PHF10 was a target of miR-409-3p. Taken together, these findings suggest that miR-409-3p may function as a novel tumor suppressor in GC and its anti-oncogenic activity may involve the direct targeting and inhibition of PHF10.

Sertoli cell only syndrome (SCOS) is one of the main causes leading to the abnormal spermatogenesis. However, the mechanisms for abnormal spermatogenesis in SCOS are still unclear. Here, we analyzed the clinical testis samples of SCOS patients by two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF/TOF MS) to find the key factors contributing to SCOS. Thirteen differential proteins were identified in clinical testis samples between normal spermatogenesis group and SCOS group. Interestingly, in these differential proteins, Heterogeneous nuclear ribonucleoprotein L(HnRNPL) was suggested as a key regulator involved in apoptosis, death and growth of spermatogenic cells by String and Pubgene bioinformatic programs. Down-regulated HnRNPL in testis samples of SCOS patients was further confirmed by immunohistochemical staining and western blotting. Moreover, in vitro and in vivo experiments demonstrated that knockdown of HnRNPL led to inhibited proliferation, increased apoptosis of spermatogenic cell but decreased apoptosis of sertoli cells. Expression of carcinoembryonic antigen-related cell adhesion molecule 1 in GC-1 cells or expression of inducible nitric oxide synthases in TM4 sertoli cells, was found to be regulated by HnRNPL. Our study first shows HnRNPL as a key factor involved in the spermatogenesis by functional proteomic studies of azoospermia patients with sertoli cell only syndrome. This article is part of a Special Issue entitled: Proteomics: The clinical link.

Traumatic brain injury (TBI) is one of the leading causes of neurological disability in young adults. Edaravone, a novel synthetic small-molecule free-radical scavenger, has been shown to have a neuroprotective effect in both animal models of cerebral ischemia and stroke patients; however, the underlying mechanism is poorly understood. In this report, we investigated the potential mechanisms of edaravone treatment in a rat model of TBI. TBI was induced in the right cerebral cortex of male adult rats using Feeney's weight-drop method. Edaravone (0.75, 1.5, or 3 mg/kg) or vehicle (normal saline) was intravenously administered at 2 and 12 h after TBI. Edaravone treatment significantly decreased hippocampal CA3 neuron loss, reduced oxidative stress, and decreased neuronal programmed cell death compared to vehicle treatment. The protective effects of edaravone treatment were also related to the pathology of TBI on non-neuronal cells, as edaravone decreased astrocyte and glial activation. Lastly, edaravone treatment significantly reduced the presence of inflammatory cytokines, cerebral edema, blood-brain barrier (BBB) permeability, and, importantly, neurological deficits following TBI. Our results suggest that edaravone exerts a neuroprotective effect in the rat model of TBI. The likely mechanism is via inhibiting oxidative stress, leading to a decreased inflammatory response and glial activation, and thereby reducing neuronal death and improving neurological function.

ZL11n is a novel furoxan-based nitric oxide (NO)-releasing derivative of farnesylthiosalicylic acid. In this study, we examined the anticancer effects and the potential mechanism of action of ZL11n in vitro and in vivo. It was found that ZL11n exhibited a favorable, selective cytotoxic effect in the HepG2 cell line. The yield of NO in the ZL11n treated HepG2 cells was much higher than in the control group and the normal human liver L-02 cells. Furthermore, the NO concentration was correlated to the degree of cytotoxicity observed. The ZL11n-induced apoptosis was assessed by Annexin V-FITC/propidium iodide flow cytometry assay. ZL11n triggered the mitochondrial/caspase apoptotic pathway by decreasing mitochondrial membrane potential, cytochrome c release from mitochondrial, and reducing the Bcl-2-to-Bax ratio, in addition to activating the caspase cascade. Simultaneously, we found that ZL11n treatment led to an increase in JNK and ERK1/2 phosphorylation. Furthermore, treatment with SP600125 (a JNK inhibitor) and PD98059 (an ERK1/2 inhibitor) prior to ZL11n treatment was found to significantly reverse ZL11n-induced apoptosis. The in vivo findings also revealed that ZL11n significantly reduced tumor volume and weight in the H(22) solid tumor mouse model examined. In short, our findings suggest that ZL11n induced apoptosis through the coordination of the mitochondrial apoptotic pathway (activated by NO) and MAPKs signaling pathway (triggered by JNK or ERK).

BACKGROUND:

Proteasome inhibitor Carbobenzoxy-Leu-Leu-leucinal (MG132) induces the unfolded protein response (UPR) in oral squamous cell carcinoma (OSCC). X-box binding protein 1 (XBP1) is a key UPR component that regulates endoplasmic reticulum stress (ER) homeostasis. This study was aimed to investigate the activation of IRE1α-TRAF2-ASK1-JNK pathway by silencing the XBP1 expression in an OSCC cell line.

METHODS:

The XBP1 specific short hairpin RNA (shRNA) plasmid vector was constructed and then transfected into the Tca-8113 cells. The effect of XBP-1 gene silencing on IRE1α-TRAF2-ASK1-JNK pathway under MG132 induced endoplasmic reticulum stress in Tca-8113 were investigated by real-time RT-PCR or western blot. Cell apoptosis was detected by flow cytometry.

RESULTS:

XBP1 expression was reduced in transfected groups and MG132 groups. shRNA-XBP1 induces IRE1α-TRAF2-ASK1 signaling activation to activate pro-apoptotic ASK1-JNK signaling. Moreover, combined shRNA-XBP1 with MG132 further enhanced downregulated XBP1 expression and upregulated activation of ASK1-JNK signaling.

CONCLUSIONS:

Silencing XBP1 expression under MG132 induced ER stress block the XBP1 survival pathway and synergism with MG132 to promote Tca8113 cell apoptosis. These findings provide a therapeutic option in oral squamous cell carcinoma by inhibition of proteasome and XBP1 splicing.

Copyright © 2015 Elsevier Masson SAS. All rights reserved.

OBJECTIVE:

Local electrical stimulation (ES) was reported to protect the brain during ischaemic injury, while the protective effect of limb remote ischaemic postconditioning (RIPostC) was confirmed. The aim of this study was to explore whether remote peripheral nerve ES exerted neuroprotection and whether this procedure shared the same neuroprotective mechanism underlying RIPostC.

METHODS:

Stroke in Sprague-Dawley rats was induced by distal middle cerebral artery occlusion (dMCAO). Rats were divided into five groups: dMCAO, RIPostC, ES, nerve resection (NR) + ES and RIPostC+ES. Twenty-four hours after reperfusion, rats were examined for neurobehavioural function, including forelimb fault placing test, Ludmila Belayev 12 score test, and infarct volume. The expression of Bcl-2 and cleaved-caspase-3 in ischaemic cortex was assessed by Western blot.

RESULTS:

In forelimb fault placing test, as compared to the highest score in the stroke-only group, RIPostC, ES and RIPostC+ES groups showed a significantly (P < 0.01) lower score. The results were similar for the Ludmila Belayev 12 score test. The infarct volume of the treatment groups also exhibited significant (P < 0.01) reduction as compared to the stroke-only group. The volume of infarct tissue in the combination of RIPostC+ES was significantly less than RIPostC and ES alone (P < 0.05). Furthermore, NR blocked the ES's protection (P < 0.05) as compared to the ES group by using above-mentioned methods. Bcl-2 was upregulated, while cleaved-caspase-3 was downregulated in the experimental groups as compared to the control group. No difference was found among the experimental groups.

DISCUSSION:

Peripheral nerve ES appears to have a neuroprotective effect in a rat dMCAO model. This effect may indicate a neural protective mechanism underlying beneficial effect of RIPostC.

BACKGROUND INFORMATION:

Microtubule affinity-regulating kinase 4 (MARK4) deficiency has been reported to negatively regulate diet-induced obesity and to mitigate insulin resistance in knockout mice, and thus may play a role in metabolic syndrome. However, the details of the molecular mechanism have yet to be revealed and the impacts of MARK4 on apoptosis remain unexplored. This study investigated the role of Mark4 in the regulation of lipid accumulation and apoptosis in adipocytes and analysed signalling pathways involved.

RESULTS:

We found that Mark4 significantly up-regulated the expression of gene sterol regulatory element binding protein-1c (SREBP-1c), fatty acid synthase (FAS), acetyl-CoA carboxylase-α (ACCα) and peroxisome proliferator activated receptor-γ (PPARγ); and reduced the protein contents of adipose triglyceride lipase (ATGL), as evidenced by the dramatic increasing lipid droplet accumulation in 3T3-L1 cells. Furthermore, a terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) apoptosis assay showed that Mark4 triggered apoptosis of adipocytes; and apoptosis was confirmed by the decreased protein contents of B-cell lymphoma-2 (Bcl-2), full-length caspase-3 and full-length caspase-9, as well as the increased expression of Bax, cleaved caspase-3 and cleaved caspase-9. Analysis of special inhibitors allowed us to offer the following explanation for these impacts of Mark4: activation of Jun N-terminal kinase1 (JNK1) promoted both apoptosis and adipogenesis, whereas inhibition of the p38 mitogen-activated protein kinase (p38MAPK) pathway contributed to lipid accumulation alone.

CONCLUSIONS:

Mark4 promotes adipogenesis in 3T3-L1 adipocytes by activating the JNK1 and inhibiting the p38MAPK pathway, and triggers apoptosis by activating the JNK1 pathway. We conclude that anti-Mark4 therapy targetted to inhibit lipid accumulation and apoptosis of adipocytes shows potential as a novel therapeutic strategy for treatment of obesity-associated metabolic complications.

© 2014 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

BACKGROUND/AIMS:

Acute kidney injury (AKI) is a major complication of kidney transplantation, resulting in early graft dysfunction. Since diuretic acetazolamide (AZA) has been shown to improve contrast induced AKI, we hypothesized that AZA also protected against ischemia-reperfusion (I/R) caused AKI.

METHODS:

An in vivo mouse renal I/R injury model and an in vitro H2O2 stimulated HK-2 cell injury model were utilized to examine the renoprotective effect of AZA. Renal injury and blood flow were measured. Nitric oxide synthase (eNOS)/Nitric oxide (NO), cell apoptosis and hypoxia-inducible factor-1α (HIF-1α) changes were analyzed.

RESULTS:

AZA reduced kidney injury scores and improved renal function by decreasing serum creatinine and BUN levels after I/R. Impaired renal blood flow was restored by increasing eNOS activities and NO production, as indicated by Laser Doppler imaging. TUNEL staining presented that AZA reduced apoptotic cells due to attenuated caspase activation and increased Bcl-2/Bax ratio. Furthermore, HIF-1α induction by AZA was demonstrated. AZA also enhanced in vitro NO production, reduced cell apoptosis and increased HIF-1α expression. Knockdown of HIF-1α by RNAi confirmed that AZA exerted its protective role depending on HIF-1α. AZA's effects were significantly reduced by Akt inhibitor LY294002.

CONCLUSIONS:

The present study demonstrated that AZA exerted a renoprotective role against I/R induced AKI through activating HIF-1α and downstream pathways.

© 2013 S. Karger AG, Basel.

BACKGROUND AND OBJECTIVE:

Senescence marker protein 30 (SMP30) is assumed to behave as an anti-aging factor. Recently, we have demonstrated that deficiency of SMP30 exacerbates angiotensin II-induced cardiac hypertrophy, dysfunction and remodeling, suggesting that SMP30 may have a protective role in the heart. Thus, this study aimed to test the hypothesis that up-regulation of SMP30 inhibits cardiac adverse remodeling in response to angiotensin II.

METHODS:

We generated transgenic mice with cardiac-specific overexpression of SMP30 gene using α-myosin heavy chain promoter. Transgenic mice and wild-type littermate mice were subjected to continuous angiotensin II infusion (800 ng/kg/min).

RESULTS:

After 14 days, heart weight and left ventricular weight were lower in transgenic mice than in wild-type mice, although blood pressure was similarly elevated during angiotensin II infusion. Cardiac hypertrophy and diastolic dysfunction in response to angiotensin II were prevented in transgenic mice compared with wild-type mice. The degree of cardiac fibrosis by angiotensin II was lower in transgenic mice than in wild-type mice. Angiotensin II-induced generation of superoxide and subsequent cellular senescence were attenuated in transgenic mouse hearts compared with wild-type mice.

CONCLUSIONS:

Cardiac-specific overexpression of SMP30 inhibited angiotensin II-induced cardiac adverse remodeling. SMP30 has a cardio-protective role with anti-oxidative and anti-aging effects and could be a novel therapeutic target to prevent cardiac hypertrophy and remodeling due to hypertension.

Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

PURPOSE:

Gastric cancer (GC) remains a leading cause of death worldwide, and an elevated expression of osteopontin (OPN) may correlate with its poor survival. Alternative splicing of OPN can result in three isoforms, OPN-a, OPN-b and OPN-c. The aim of our current study is to examine the expression pattern and biological functions of OPN splice variants in GC.

METHODS:

Firstly, we evaluated the expression of OPN splice variants in 7 gastric cell lines, 101 pairs of GC tissues and their adjacent non-tumor tissues by Quantative real-time PCR (QT-PCR). Gain-of-function experiments were subsequently performed to determine their diverse roles in malignant behaviors of GC. Besides, their differential effects on the regulation of crucial downstream molecules were further explored in the anti-apoptotic and pro-metastatic process.

RESULTS:

We found that OPN-b is the dominant kind of OPN isoform in GC cell lines. Although the expression levels of three variants were all elevated in GC tissues, increased OPN-b or OPN-c expression could correlate with clinicopathological features. Functional analyses further showed that OPN-b most strongly promoted GC cell survival possibly by regulation of Bcl-2 family proteins and CD44v expressions. Moreover, OPN-c most effectively stimulated GC metastatic activity by increasing secretion of MMP-2, uPa, and IL-8.

CONCLUSIONS:

Our results suggest that OPN splice variants differentially exert clinicopathological features and biological functions in GC. Therefore, focusing on specific OPN isoform could be a novel direction for developing diagnostic and therapeutic approaches in GC.

OBJECTIVE:

To investigate the effect of mesenchymal stem cells isolated from Wharton jelly of umbilical cord (WJ-MSCs) on ameliorating damaged human endometrial stromal cells (ESCs).

DESIGN:

Experimental study.

SETTING:

University-affiliated hospital.

PATIENT(S):

Sixteen endometrial tissues were obtained from women undergoing hysterectomy. Eight umbilical cords were obtained from full-term deliveries.

INTERVENTION(S):

ESCs were cultured with mifepristone to get damaged ESCs, then damaged ESCs were co-cultured with WJ-MSCs.

MAIN OUTCOME MEASURE(S):

The proliferation of ESCs was investigated by Cell Counting Kit 8, and the percentage of apoptosis by annexin-V-fluorescein isothiocyanate binding. The mRNA and protein expression of vascular endothelial growth factor (VEGF) and caspases 3, 8, and 9 were determined by one-step quantitative real-time polymerase chain reaction and Western blot.

RESULT(S):

After exposure to mifepristone, the proliferation of ESCs decreased and the apoptosis percentage increased in a dose- and time-dependent manner. At a certain dose and duration, this damage continued even after the withdrawal of mifepristone at 48 hours. When the damaged ESCs were cocultured with WJ-MSCs, the proliferation of these damaged cells was significantly increased and apoptosis percentage decreased. In addition, the level of VEGF mRNA and protein decreased and that of caspases 3, 8, and 9 increased.

CONCLUSION(S):

WJ-MSCs may serve as a promising treatment approach to ameliorate endometrial damage.

Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

The activation of oncogenes and the inactivation of tumor suppressor genes by mutations or chronic hepatitis virus infections play key roles in the pathogenesis of hepatocellular carcinoma (HCC). Here we report that RN181, a really interesting new gene finger domain-containing protein, was down-regulated in highly malignant cell lines and in tumor cells of 139 HCC clinical samples in comparison with adjacent normal liver tissues. The expression of RN181 was strongly associated with the pathological grade of HCC. Alterations of the expression of RN181 by retrovirus-transduced up-regulation and short hairpin RNA-mediated down-regulation demonstrated the function of RN181 as a tumor suppressor because it decreased the proliferation and colony formation of HCC cells in vitro and inhibited tumor growth in vivo by suppressing cell proliferation and enhancing cell apoptosis in xenografted tumors. Proteomic analyses showed that RN181 regulates the expression of many proteins that are important in many cellular processes. Statistical analyses identified 33 proteins with consistent changes (≥2-fold) in RN181-transformed cells. Ten of these proteins were up-regulated by RN181, and 23 were down-regulated. Representative proteins were validated by western blotting. Interaction network investigations revealed that 20 RN181-regulated proteins could integrate several key biological processes such as survival, metabolism, and mitogen-activated protein kinase (MAPK) pathways. Remarkably, 11 of the 33 proteins are associated with MAPK signaling in one or more ways. RN181 suppressed the tyrosine phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) in cell lines and in tumor cells of xenografts and HCC clinical samples, and removing the suppression increased tumor growth.

CONCLUSION:

We have shown that RN181 suppresses the tumorigenesis of HCC through the inhibition of ERK/MAPK signaling in the liver. Our results provide new insights into the pathogenesis of HCC and may help with the development of novel therapeutic strategies.

Copyright © 2011 American Association for the Study of Liver Diseases.