Let-7i-5p regulates osteogenic differentiation of bone marrow mesenchymal stem cells induced by psoralen by targeting CKIP-1

AbstractPrevious studies have shown that psoralen can treat osteoporosis by inducing osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). CKIP-1 is an inhibitor of bone formation and plays a negative regulatory role in the osteogenic differentiation of BMSCs. MicroRNA (miRNA) is a kind of small single-stranded non-coding RNA, which regulates the occurrence and development process of cell proliferation, apoptosis, differentiation and metabolism. Studies have shown that miRNA can affect the proliferation and differentiation of BMSCs by targeting and regulating the expression of related genes. However, whether microRNA can regulate psoralen-induced osteogenic differentiation and its specific mechanisms remain unclear. The aim of this study was to identify miRNA target genes regulating the osteogenic differentiation of BMSCs induced by psoralen and further analyze the mechanism.miRNA microarray was performed to screen the differentially expressed mirnas induced by psoralen, and bioinformatics analysis and luciferase reporter gene assay were used to determine the target sites of let-7i-5p. The mechanism of let-7i-5p in psoralen induced osteogenic differentiation of BMSCs was investigated using in vitro overexpression or inhibition approaches.The results showed that miRNA microarray analysis and reverse transcription quantitative PCR further confirmed that let-7i-5p was up-regulated during the process of psoralin-induced osteogenic differentiation of BMSCs.Bioinformatics analysis and luciferase reporter gene assay confirmed CKIP-1 as a potential target of let-7i-5p.Overexpression of CKIP-1 by transfection with CKIP-1 mimetic significantly inhibited the expression of BMP, Runx2, and Smad1, while CKIP-1 inhibitor promoted their expression.Overexpression of let-7i-5p partially relieved the inhibitory effect of CKIP-1 on osteogenic differentiation of BMSCs.Our results suggest that let-7i-5p regulates psoralen-induced osteogenic differentiation of BMSCs by targeting CKIP-1, which provides a new therapeutic target for osteoporosis.