Anti-Bax Anticorps (A29688)

This study is aimed at investigating whether human umbilical cord mesenchymal stem cell- (hucMSC-) derived exosomes (hucMSC-exosomes) have a protective effect on acute myocardial infarction (AMI). Exosomes were characterized under transmission electron microscopy and the particles of exosomes were further examined through nanoparticle tracking analysis. Exosomes (400 μg protein) were intravenously administrated immediately following ligation of the left anterior descending (LAD) coronary artery in rats. Cardiac function was evaluated by echocardiography and apoptotic cells were counted using TUNEL staining. The cardiac fibrosis was assessed using Masson's trichrome staining. The Ki67 positive cells in ischemic myocardium were determined using immunohistochemistry. The effect of hucMSC-exosomes on blood vessel formation was evaluated through tube formation and migration of human umbilical vein endothelial cells (EA.hy926 cells). The results indicated that ligation of the LAD coronary artery reduced cardiac function and induced cardiomyocyte apoptosis. Administration of hucMSC-exosomes significantly improved cardiac systolic function and reduced cardiac fibrosis. Moreover, hucMSC-exosomes protected myocardial cells from apoptosis and promoted the tube formation and migration of EA.hy926 cells. It is concluded that hucMSC-exosomes improved cardiac systolic function by protecting myocardial cells from apoptosis and promoting angiogenesis. These effects of hucMSC-exosomes might be associated with regulating the expression of Bcl-2 family.

Dichlorodiphenoxytrichloroethane (DDT) is a known persistent organic pollutant and liver damage toxicant. However, there has been little emphasis on the mechanism underlying liver damage toxicity of DDT and the relevant effective inhibitors. Hence, the present study was conducted to explore the protective effects of vitamin C (VC) and vitamin E (VE) on the cytotoxicity of DDT in HL-7702 cells and elaborate the specific molecular mechanisms. The results demonstrated that p,p'-DDT exposure at over 10 µM depleted cell viability of HL-7702 cells and led to cell apoptotic. p,p'-DDT treatment elevated the level of reactive oxygen species (ROS) generation, induced mitochondrial membrane potential, and released cytochrome c into the cytosol, with subsequent elevations of Bax and p53, along with suppression of Bcl-2. In addition, the activations of caspase-3 and -8 were triggered. Furthermore, p,p'-DDT promoted the expressions of NF-κB and FasL. When the cells were exposed to the NF-κB inhibitor (PDTC), the up-regulated expression of FasL was attenuated. Strikingly, these alterations caused by DDT treatment were prevented or reversed by the addition of VC or VE, and the protective effects of co-treatment with VC and VE were higher than the single supplement with p,p'-DDT. Taken together, these findings provide novel experimental evidences supporting that VC or/and VE could reduce p,p'-DDT-induced cytotoxicity of HL-7702 cells via the ROS-mediated mitochondrial pathway and NF-κB/FasL pathway.

Musk has been traditionally used in East Asia to alleviate the symptoms of angina pectoris. However, it remains unclear as to whether muscone, the main active ingredient of musk, has any beneficial effects on persistent myocardial ischemia in vivo. The aim of the present study was to investigate whether muscone can improve cardiac function and attenuate myocardial remodeling following myocardial infarction (MI) in mice. Mice were subjected to permanent ligation of the left anterior descending coronary artery to induce MI, and then randomly treated with muscone (2 mg/kg/day) or the vehicle (normal saline) for 3 weeks. Sham-operated mice were used as controls and were also administered the vehicle (normal saline). Treatment with muscone significantly improved cardiac function and exercise tolerance, as evidenced by the decrease in the left ventricular end-systolic diameter, left ventricular end-diastolic diameter, as well as an increase in the left ventricular ejection fraction, left ventricular fractional shortening and time to exhaustion during swimming. Pathological and morphological assessments indicated that treatment with muscone alleviated myocardial fibrosis, collagen deposition and improved the heart weight/body weight ratio. Muscone inhibited the inflammatory response by reducing the expression of transforming growth factor (TGF)‑β1, tumor necrosis factor (TNF)-α, interleukin (IL)-1β and nuclear factor (NF)-κB. Treatment with muscone also reduced myocardial apoptosis by enhancing Bcl-2 and suppressing Bax expression. Muscone also induced the phosphorylation of protein kinase B (Akt) and endothelial nitric oxide synthase (eNOS). Our results demonstrate that muscone ameliorates cardiac remodeling and dysfunction induced by MI by exerting anti-fibrotic, anti-inflammatory and anti-apoptotic effects in the ischemic myocardium.

In this study, the anticancer effect of a newly synthesized flavonoid FV-429, against human breast cancer MDA-MB-231 cells, and the underlying mechanisms were investigated. FV-429 triggered the apoptosis and simultaneously inhibited the glycolysis of MDA-MB-231 cells. Both the HK II activity and its level in mitochondria were significantly down regulated by FV-429. Moreover, FV-429 weakened the interaction between HKII and VDAC, stimulated the detachment of HK II from the mitochondria, and resulted in the opening of the mitochondrial permeability transition pores. Thus FV-429 induced the mitochondrial-mediated apoptosis, showing increased Bax/Bcl-2 ratio, loss of mitochondrial membrane potential (MMP) and activation of caspase-3 and -9, cytochrome c (Cyt c) release, and apoptosis inducing factor (AIF) transposition. Further research revealed that the phosphorylation of mitochondrial HKII via Akt was responsible for the dissociation of HKII and the decreased HKII activity induced by FV-429. Taken together, FV-429 inhibited the phosphorylation of HKII, down-regulated its activity, and stimulated the release of HKII from the mitochondria, resulting the inhibited glycolysis and mitochondrial-mediated apoptosis. The studies provide a molecular basis for the development of flavonoid compounds as novel anticancer agents for breast cancer.

© 2015 Wiley Periodicals, Inc.

Mesenchymal stem cells (MSCs) have the potential to facilitate cardiac repair following acute myocardial infarction. However, MSC therapy is limited by apoptosis of the stem cells following transplantation. Hydrogen sulfide (H2S) has recently been proposed as an endogenous mediator of cell apoptosis in various systems. The aim of the present study was to investigate the mechanism underlying the antiapoptotic effect of the endogenous cystathionine γ-lyase (CSE)/H2S system in MSCs cultivated in conditions of hypoxia and serum deprivation (H/SD). Western blotting was performed in order to determine the expression of proteins associated with the mitochondrial injury pathway, endoplasmic reticulum stress and the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. It was demonstrated that H/SD is able to significantly induce apoptosis in MSCs. CSE overexpression, which enhances the endogenous H2S level, protects MSCs from H/SD-induced apoptosis via attenuation of the mitochondrial injury pathway, inhibition of endoplasmic reticulum stress and activation of the PI3K/Akt signaling pathway. In conclusion, the present findings suggest that modulation of the CSE/H2S system may a therapeutic approach with which to promote the viability of transplanted MSCs.

Recent studies have revealed that osthole, an active constituent isolated from the fruit of Cnidium monnieri (L.) Cusson, a traditional Chinese medicine, possesses anticancer activity. However, its effect on breast cancer cells so far has not been elucidated clearly. In the present study, we evaluated the effects of osthole on the proliferation, cell cycle and apoptosis of human breast cancer cells MDA-MB 435. We demonstrated that osthole is effective in inhibiting the proliferation of MDA-MB 435 cells, The mitochondrion-mediated apoptotic pathway was involved in apoptosis induced by osthole, as indicated by activation of caspase-9 and caspase-3 followed by PARP degradation. The mechanism underlying its effect on the induction of G1 phase arrest was due to the up-regulation of p53 and p21 and down-regulation of Cdk2 and cyclin D1 expression. Were observed taken together, these findings suggest that the anticancer efficacy of osthole is mediated via induction of cell cycle arrest and apoptosis in human breast cancer cells and osthole may be a potential chemotherapeutic agent against human breast 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.

Diabetic erectile dysfunction (ED) is a common complication in diabetes mellitus, and the efficacy of first-line therapies is not satisfactory. Recent studies revealed that corporal apoptosis was responsible for the nonresponsiveness of severe ED to phosphodiesterase type 5 inhibitors. Mitofusin 2 (Mfn2) is a versatile protein, regulating mitochondrial morphology and playing an important role in apoptosis. Several studies showed that expression of Mfn2 was decreased in STZ-induced diabetic rats' kidney, myocardium and retina, which was associated with diabetic nephropathy, cardiomyopathy and retinopathy respectively. In this study, our aim was to explore the expression of Mfn2 and apoptosis in diabetic rats' penes. We found that erectile function (ICP/MAP) elicited by electrical stimulation of cavernous nerve was markedly impaired in diabetic rats compared with the normal rats. The mRNA and protein levels of Mfn2 were found to be significantly reduced in diabetic rats' penile tissues. Compared with normal rats, the content of smooth muscle and B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein (Bax) ratio were dramatically decreased, and penile apoptotic index and expression of activated-caspase-3 were dramatically increased in diabetic rats. This data indicated that repression of Mfn2 in diabetic rats' penes might be associated with excessive apoptosis in diabetes-induced severe ED.

Recent studies have emphasized the importance of apoptosis in subarachnoid hemorrhage (SAH) and the subsequent early brain injury. However, the apoptotic pathways induced by SAH in different brain regions are not fully understood. We investigated gene expression levels of classical apoptosis-related molecules (caspase-3, bax, and bcl-2) following SAH in the hippocampus of male Wistar rats. Temporally specific changes were found in caspase-3 and bax messenger RNA only. Interestingly, we found increased expression of bax, but not caspase-3, in the prefrontal cortex, which indicates different molecular mechanisms of apoptosis in distinct brain regions. Most important, changes in expression were reversed by functional blockade of tumor necrosis factor-alpha, which has a critical role in brain injury. In addition, we found that apoptosis induced by SAH may be associated with a relative elevation of pro-brain derived neurotrophic factor.

PURPOSE:

In our previous studies, the protective activity of recombinant hirudin variant III (rHV3) against galactose-mediated lens epithelial cells damage was shown using human lens epithelial cell line. In this study, we applied similar methodology to primary rat lens epithelial cells (rLECs) to see whether the same effect and mechanism remain.

METHODS:

The rLECs were cultured in D/F(12)-10% fetal bovine serum (FBS) medium containing 50 mM d-galactose with or without rHV3. Cell viability was assessed by methylthiazol tetrazolium (MTT) assay. Reactive oxygen species (ROS) were detected with 2',7'-dichlorofluorescein (DCF). Levels of malondialdehyde (MDA) and free glutathione (GSH), activities of glutathione s-transferase (GST), catalase, superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) were measured using commercial quantification kits. Cell apoptosis was evaluated by DNA fragmentation assay and flow cytometric analysis. The gene expression of Bcl-2 and Bax was analyzed using reverse transcription-PCR (RT-PCR) and western blot.

RESULTS:

Cell viability, ROS, MDA and GSH levels, antioxidant enzymes were significantly altered when rHV3 was administrated. rHV3 also showed prevention of apoptosis of rLECs. In addition, rHV3 treatment significantly increased galactose-induced Bcl-2 downregulation, and decreased Bax upregulation.

CONCLUSIONS:

The protective effects of rHV3 may be due to effective recovery of the antioxidative defense system, resulting in antiapoptosis. In addition, rHV3 may be able to inhibit apoptosis of lens epithelial cells through the mitochondrial pathways of apoptosis by regulating Bcl-2 and Bax expression.

BACKGROUND:

Recently, 1,5-dicaffeoylquinic acid (1,5-DQA), a caffeoylquinic acid derivative isolated from Aster scaber, was found to have neuroprotective effects. However, the protective mechanisms of 1,5-DQA have not yet been clearly identified. The purpose of this study was to explore the protective mechanisms of 1,5-DQA on neuronal culture.

METHODS:

We investigated the neuroprotective effects of 1,5-DQA against amyloid β(1-42) (Aβ(42))-induced neurotoxicity in primary neuronal culture. To evaluate the neuroprotective effects of 1,5-DQA, primary cultured cortical neurons from neonate rats were pretreated with 1,5-DQA for 2 hours and then treated with 40 µmol/L Aβ(42) for 6 hours. Cell counting kit-8, Hoechst staining and Western blotting were used for detecting the protective mechanism. Comparisons between two groups were evaluated by independent t test, and multiple comparisons were analyzed by one-way analysis of variance (ANOVA).

RESULTS:

1,5-DQA treated neurons showed increased neuronal cell viability against Aβ(42) toxicity in a concentration-dependent manner, both phosphoinositide 3-kinase (PI3K)/Akt and extracellular regulated protein kinase 1/2 (Erk1/2) were activated by 1,5-DQA with stimulating their upstream tyrosine kinase A (Trk A). However, the neuroprotective effects of 1,5-DQA were blocked by LY294002, a PI3K inhibitor, but not by PD98059, an inhibitor of mitogen-activated protein kinase kinase. Furthermore, 1,5-DQA's anti-apoptotic potential was related to the enhanced inactivating phosphorylation of glycogen synthase kinase 3β (GSK3β) and the modulation of expression of apoptosis-related protein Bcl-2/Bax.

CONCLUSION:

These results suggest that 1,5-DQA prevents Aβ(42)-induced neurotoxicity through the activation of PI3K/Akt followed by the stimulation of Trk A, then the inhibition of GSK3β as well as the modulation of Bcl-2/Bax.