TITLE:
DNA Methyltransferase Inhibitors Induce Cerebral Dopamine Neurotrophic Factor Expression in C6 Glioma Cells
AUTHORS:
Sumeya Z. Mukhtar, Lennard P. Niles
KEYWORDS:
CDNF, MANF, 5-Azacytidine, 5-Aza-2’-deoxycytidine, Zebularine, Gene Expression
JOURNAL NAME:
American Journal of Molecular Biology,
Vol.13 No.3,
July
21,
2023
ABSTRACT: Cerebral dopamine neurotrophic factor (CDNF) and mesencephalic astrocyte-derived neurotrophic factor (MANF) are involved in neuroprotection and mitigating endoplasmic reticulum (ER) stress in the brain and peripheral organs. In earlier work, an increase in histone acetylation, following treatment with an epigenetic modulator, valproic acid, was associated with induction of CDNF and MANF in cultured cells and rat brain. These findings prompted an investigation of the effects of DNA methyltransferase (DNMT) inhibitors, which can alter epigenetic function, on the expression of CDNF and MANF. Rat C6 glioma cells were treated with a micromolar range of DNMT inhibitors: 5-aza-2’-deoxycytidine (DAC or decitabine), 5-azacytidine (AZA) or zebularine (ZEB) for 24 h. Subsequently, qPCR analysis was used to examine the mRNA expression of DNMT1, ten-eleven translocation methylcytosine dioxygenase 2 (TET-2), CDNF and MANF. A significant dose-dependent decrease in DNMT1 mRNA levels, together with a significant increase in TET-2 expression, was observed following treatment with AZA or DAC. Importantly, DAC, AZA and ZEB caused a significant dose-dependent increase in CDNF mRNA levels. In contrast, MANF mRNA expression decreased following treatment with AZA, with no significant effects observed with DAC or ZEB. Western analysis revealed no significant changes in CDNF protein levels following treatment with DAC for 24 h. The significant increase in CDNF expression, following treatment with DNMT1 inhibitors, suggests that DNA methylation is involved in the regulation of this neurotrophic factor. Clarification of the epigenetic or other mechanisms underlying the regulation of CDNF may provide novel therapeutic approaches in neurodegenerative and ER stress-related disorders.