Osteoarthritis (OA) is a commonly known prevalent joint disease, with limited therapeutic methods. This study aimed to investigate the functions of miRNA-132 (miR-132) in the modulation of PTEN/PI3K/AKT signaling pathway in the development and progression of osteoarthritis.
Eight male osteoarthritic patients and eight healthy males were recruited. Male Sprague Dawley (SD) rats were used for cellular experiments. QRT-PCR was performed to detect the expression levels of miR-132, PTEN, PI3K and AKT. MTT assay and apoptosis assay were carried out to measure the cell proliferation rate and cell apoptosis rate, respectively. Western blotting was employed to detect the protein expression of related RNAs and inflammatory factors.
In osteoarthritic patients, the expression level of miR-132 was decreased, compared with that in the normal group. Over-expression of miR-132 elevated cell proliferation and decreased apoptosis of chondrocytes. Down-regulation of miR-132 decreased cell proliferation and induced apoptosis in chondrocytes. In addition, down-regulation of miR-132 promoted the expression of Bax protein and activated caspase-3/9, increased inflammation divisors. PTEN inhibitor antagonized the destructive effect of the miR-132 inhibitor on cell proliferation of chondrocytes. PI3K inhibitor increased the destructive effect of the miR-132 inhibitor on osteoarthritis.
In conclusion, miR-132 is an important regulator of osteoarthritis in chondrocytes through the PTEN/PI3K/AKT signaling pathway.