Study on the mechanism of miR-23b-3p regulating osteogenic differentiation of renal interstitial fibroblasts and participating in Randall's plaque formation / 安徽医科大学学报

ABSTRACT

Objective To explore the effect of miR-23b-3p regulation on osteogenic differentiation of renal intersti-tial fibroblasts(hRIFs)on the formation of Randall plaque and its possible mechanism.Methods qRT-PCR was used to detect the expression levels of miR-23b-3p and osteogenic marker:myocyte enhancer factor 2C(MEF2C),osteocalcin(OCN),osteopontin(OPN),runt-related transcription factor 2(Runx2)mRNA in Randall plaque tis-sue of CaOx stone patients(RP)and normal papillary tissue of kidney tumor patients undergoing nephrectomy(nRP).Isolation and culture of human normal hRIFs were isolated and cultured in vitro.The miR-23b-3p overex-pression plasmid pSi-miR-23b-3p and its negative no-load plasmid pSi-NC,the MEF2C lentivirus overexpression plasmid Lv-MEF2C and the no-load plasmid Lv-NC were transfected into hRIFs cells,and the cells were induced to osteogenic differentiation for 14 days.The activity of alkaline phosphatase(ALP)was determined by ELISA.Aliz-arin red staining was used to observe the formation of mineralized nodules.The expression levels of miR-23b-3p and MEF2C,OCN,OPN,Runx2 mRNA were detected by qRT-PCR.The expression level of MEF2C protein was de-tected by Western blot.Dual luciferase reporter gene assay verified the targeting relationship between miR-23b-3p and MEF2C.Results ① Compared with the nRP group,miR-23b-3p was low expressed and MEF2C,OCN,OPN,and Runx2 were highly expressed in the RP group.② 14 days after osteogenic induction of hRIFs cells,the activity of ALP in cells significantly increased,the ability of cells to form mineralized nodules was enhanced,the expression level of miR-23b-3p significantly decreased,the mRNA expression levels of MEF2C,OCN,OPN,and Runx2 significantly increased,and the expression level of MEF2C protein significantly increased.③ Overexpres-sion of miR-23b-3p decreased the activity of ALP in hRIFs cells after osteogenic induction,inhibited the formation of mineralized nodules in cells,and down-regulated the mRNA expression levels of OCN,OPN,and Runx2 in cells.④ Overexpression of MEF2C reversed the inhibitory effect of miR-23b-3p overexpression on osteoblast differ-entiation of hRIFs cells.⑤ MEF2C was the downstream target gene of miR-23b-3p.Conclusion miR-23b-3p is underexpressed in RP tissues and during osteoblastic differentiation of hRIFs cells.Up-regulation of miR-23b-3p in-hibits osteogenic differentiation of hRIFs cells,and its mechanism may be related to targeted silencing MEF2C.