MicroRNA-532-5p is implicated in the regulation of osteoporosis by forkhead box O1 and osteoblast differentiation.

Background: MicroRNAs (miRNAs) are critical regulators in osteogenesis and cartilage formation. This study was designed to investigate whether miR-532-5p plays a role in the regulation of osteoporosis.

Methods: Osteoporotic fractures (OP group, n = 10) or osteoarthritis without osteoporosis (control group, n = 10) were selected as subjects in this study. Quantitative analysis of gene expression was performed by RT-PCR. Western blot was used to determine the expression levels of protein forkhead O1 (FOXO1). Bioinformatics analyses and luciferase reporter assay were used to verify the downstream target of miR-532-5p.

Results: Compared with the non-osteoporotic controls, miR-532-5p was upregulated in osteoporotic samples, and expression of miR-532-5p was downregulated in the osteogenic C2C12 cell model. Overexpression of miR-532-5p resulted in decreased expression levels of key osteoblast markers, including alkaline phosphatase (ALP), osteocalcin (OC), and collagen type I alpha 1 (COL1A1). The inhibitory results of miR-532-5p were reversed. MiR-532-5p contained a putative FOXO1 binding site. Moreover, miR-532-5p inhibited the expression of FOXO1, and overexpression of FOXO1 inhibited the effect of miR-532-5p on osteoblast markers.

Conclusions: MiR-532-5p can provide references to osteoporosis by regulating the expression of FOXO1 and osteoblast differentiation. MiR-532-5p might serve as a therapeutic target for osteoporosis.