Research Paper Volume 16, Issue 4 pp 3302—3331

Exosomes as nanostructures deliver miR-204 in alleviation of mitochondrial dysfunction in diabetic nephropathy through suppressing methyltransferase-like 7A-mediated CIDEC N6-methyladenosine methylation

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Figure 8. METTL7A silencing prevents DN progression by downregulating CIDEC m6A methylation in HG-induced HK-2 cells. (A, B) The expression of CIDEC in HK-2 cells using qRT-PCR and western blotting. (C) CIDEC m6A methylation level in HK-2 cells using MeRIP-qPCR. (AC) Data were expressed as mean ± standard deviation. #p < 0.05 and ##p < 0.01 vs. HG + si-NC group. (AC) HG-induced HK-2 cells were partially transfected with si-METTL7A or si-NC (negative control) for 48 h to explore the effects of METTL7A on CIDEC and its m6A methylation. (D) Determination of the interaction between METTL7A and CIDEC in HEK293T cells using RNA pulldown assay. (E, F) The expression of CIDEC in HK-2 cells using western blotting and qRT-PCR. (G, H) HK-2 cell viability and apoptosis using CCK-8 and flow cytometry, respectively. (I) The levels of MDA, SOD, GPX, and CAT in HK-2 cells using ELISA. (EI) Empty vector (control), si-CIDEC, or/and oe-METTL7A were transfected into HG-induced HK-2 cells to further determine the interaction between METTL7A and CIDEC in DN. Data were expressed as mean ± standard deviation. ##p < 0.01 vs. HG + vector group; ^^p < 0.01 vs. HG + si-CIDEC group. Abbreviations: METTL: methyltransferase-like; DN: diabetic nephropathy; CIDEC: cell death-inducing DFF45-like effector C; m6A: N6-methyladenosine; HG: high glucose; qRT-PCR: quantitative real-time polymerase chain reaction; MeRIP-qPCR: methylated RNA immunoprecipitation-PCR; CCK-8: cell counting kit-8; MDA: malondialdehyde; SOD: superoxide dismutase; GPX: glutathione peroxidase; CAT: catalase; ELISA: enzyme-linked immunosorbent assay.