Anti-MAP1LC3A Antibody (A30841)

Folic acid (FA) is an extremely important nutrient for brain formation and development. FA deficiency is highly linked to brain degeneration and age-related diseases, which are also associated with autophagic activities and circadian rhythm in hippocampal neurons. However, little is known how autophagy- and circadian-related genes in hippocampal neurons are regulated under FA deficiency. Here, hippocampal neuroncells (HT-22) were employed to determine the effect of FA deprivation (FD) on the expression of relevant genes and to reveal the potential role of glucocorticoid receptor (GR). FD increased autophagic activities in HT-22 cells, associated with significantly (P<0.05) enhanced GR activation indicated by higher ratio of GR phosphorylation. Out of 17 autophagy-related genes determined, 8 was significantly (P<0.05) up-regulated in FD group, which includes ATG2b, ATG3, ATG4c, ATG5, ATG10, ATG12, ATG13 and ATG14. Meanwhile, 4 out of 7 circadian-related genes detected, Clock, Cry1, Cry2 and Per2, were significantly (P<0.05) up-regulated. The protein content of autophagy markers, LC3A and LC3B, was also increased significantly (P<0.05). ChIP assay showed that FD promoted (P<0.05) GR binding to the promoter sequence of ATG3 and Per2. Moreover, MeDIP analysis demonstrated significant (P<0.05) hypomethylation in the promoter sequence of ATG12, ATG13 and Per2 genes. Together, we speculate that FD increases the transcription of autophagy- and circadian-related genes through, at least partly, GR-mediated pathway. Our results provide a basis for future investigations into the intracellular regulatory network in response to folate deficiency.

This study investigated the relevance between pulp vitality and autophagy in aged human dental pulp cells (HDPCs) and whether peroxisome proliferator-activated receptor gamma (PPARγ) affects autophagy regulation for homeostasis in the aging progress. In vivo experiments were used in human and Sprague-Dawley rat teeth obtained from young and adult individuals. Aging- and autophagy-related molecules were determined by immunohistochemistry and hematoxylin and eosin staining. HDPCs were serially subcultured until spontaneously arrested for in vitro aging, and the replication deficiency adenovirus was introduced for PPARγ overexpression. Subsequently, the effect of PPARγ on regulation of autophagy molecules, mitochondria activity, and cell viability was assessed using Western blotting, confocal microscopy, and the MTT assay, respectively. In adult pulp tissue, autophagy molecules (autophagy protein 5, microtubule-associated protein 1A/1B light chain, and Beclin-1) were increased, but aging-related (PPARγ and heme oxygenase 1 [HO-1]) and dentinogenesis (dentin sialophosphoprotein and dentin matrix acidic phosphoprotein) molecules were decreased. In aged HDPCs, autophagy and intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 were increased, while PPARγ and HO-1 were decreased. Under stimulation with lipopolysaccharide, autophagy- and aging-related molecules were differentially expressed between young and aged cells. PPARγ induced HO-1 and autophagy molecules but reduced inflammatory molecules in aged cells. In addition, PPARγ activated strong mitochondrial activity and cell viability in aging cells. Inhibition of HO-1 by tin protoporphyrin IX exacerbated autophagy and mitochondrial activity as well as cell viability in young cells. This study indicates that PPARγ maintains pulp homeostasis through the regulation of autophagy molecules during the life span of HDPCs.