Epigallocatechin Gallate Induces the Demethylation of Actinin Alpha 4 to Inhibit Diabetic Nephropathy Renal Fibrosis via the NF-KB Signaling Pathway In Vitro.

UNLABELLED

Actinin alpha 4 () is expressed in the kidney podocytes. gene methylation in patients with diabetic nephropathy (DN) remains high. Underlying mechanism of epigallocatechin-3-gallate (EGCG) inducing demethylation, and its inhibitory effect on DN renal fibrosis remains unclear.

METHODS

Human podocyte cell line, HPC, was treated with high glucose to establish model of DN. The levels of cytokines, vascular endothelial growth factor (VEGF) and interleukin (IL)-8, and fibrosis markers, alpha smooth muscle actin (α-SMA) and fibronectin (FN), were determined using enzyme-linked immunosorbent assay. HPC cells were treated with EGCG, and cell viability was determined by MTT assay, ACTN4 gene methylation was analyzed by MSP. mRNA and protein expression levels were measured using RT-qPCR and Western blotting, respectively.

RESULTS

Actinin alpha 4 gene promoter was hypermethylated in the high glucose-treated groups. EGCG reversed the hypermethylated status of , along with the upregulation of ACTN4 levels and downregulation of DNA methyltransferase 1 (DNMT1), NF-κB p65, p-NF-κB p65, IκB-α, VEGF, IL-8, α-SMA, and FN levels (<.05).

CONCLUSION

Epigallocatechin-3-gallate reduced hypermethylation of in HPC cells by downregulating DNMT1 expression and restoring expression, contributing to the upregulation of the NF-KB p65, p-NF-KB p65, IKB-α, VEGF, IL-8, α-SMA, and FN levels (P<.05).