DNA Methyltransferase Inhibitor 5-AZA-DC Regulates TGFβ1-Mediated Alteration of Neuroglial Cell Functions after Oxidative Stress

Abstract

5-AZA-DC is an efficient methylation inhibitor that inhibits methylation of target DNA. In this study, we explored the effects of 5-AZA-DC on the regulation of TGFβ1 on target genes in neuroglial cell, as well as neuroglial cell functions under oxidative stress. The oxidative stress was constructed by editing CRISPR/Cas9 for knock out Ang-1 and ApoE4 genes. Cells were subjected to TGFβ1OE (or shTGFβ1) transfection and/or 5-AZA-DC intervention. Results showed that under oxidative stress, both TGFβ1OE and shTGFβ1 transfection raised DNMT1, but reduced TGFβ1, PTEN, and TSC2 expressions in neuroglial cells. TGFβ1 directly bind to the promoter of PTEN gene. 5-AZA-DC intervention lowered DNMT1 and raised TGFβ1 expression, as well as promoted the binding between TGFβ1 and promoter of PTEN. TGFβ1OE caused a significant increase in the DNA demethylation level of PTEN promoter, while 5-AZA-DC intervention reduced the DNA demethylation level of PTEN promoter. Under oxidative stress, TGFβ1OE (or shTGFβ1) transfection inhibited neuroglial cell proliferation, migration, and invasion, promoted cell apoptosis. 5-AZA-DC intervention alleviated TGFβ1OE (or shTGFβ1) transfection caused neuroglial cell proliferation, migration, and invasion inhibition, as well as cell apoptosis. To conclude, these results suggest that 5-AZA-DC can be used as a potential drug for epigenetic therapy on oxidative stress damage in neuroglial cells. The findings of this research provide theoretical basis and research ideas for methylation drug intervention and TGFβ1 gene as a possible precise target of glial oxidative stress diagnosis and treatment.