Bone marrow fatty acids affect osteoblastic differentiation through miR-92b-3p in the early stages of postmenopausal osteoporosis

Osteoporosis is partially caused by dysfunctions in the commitment, differentiation or survival of osteoblasts. Bone marrow fatty acids affect bone resorption and formation. In this study, we aimed to explore the role of fatty acids in the early stages of postmenopausal osteoporosis and determine whether they influence osteogenic differentiation through microRNAs. A quantitative analysis of bone marrow fatty acids early after ovariectomy or sham surgery in a rat osteoporotic model was performed using gas chromatography/mass spectrometry. The results showed that palmitoleate was significantly decreased on postoperative day 3 while both pentadecanoate and palmitoleate were significantly decreased on postoperative day 5 in rats in the ovariectomized group compared with those in the sham group. Palmitoleate promotes osteogenic differentiation, whereas pentadecanoate inhibits this process. Palmitoleate levels were higher than those of pentadecanoate; therefore, the early overall effect of significant bone marrow fatty acid changes was a decrease in osteogenic differentiation. We also found that miR-92b-3p inhibited osteoblastogenesis via the miR-92b-3p/phosphatase and tensin homolog regulatory axis. Palmitoleate, pentadecanoate, and palmitate influenced the osteoblastogenesis of MC3T3-E1 cells through miR92b-3p. Taken together, we propose that miR-92b-3p mediates the effect of bone marrow fatty acids on osteoblast differentiation in the early stages of osteoporosis. These findings may provide molecular insights for the treatment of osteoporosis.

Automated summary

Osteoporosis is partly caused by dysfunctions in osteoblasts' commitment, differentiation, or survival. Bone marrow fatty acids can affect bone resorption and formation. This study aims to investigate the role of fatty acids in the early stages of postmenopausal osteoporosis and determine if they influence osteogenic differentiation through microRNAs. The results showed a decrease in palmitoleate on postoperative day 3 and a decrease in both pentadecanoate and palmitoleate on postoperative day 5 in the ovariectomized rat group. Palmitoleate promotes osteogenic differentiation, while pentadecanoate inhibits it. miR-92b-3p was found to inhibit osteoblastogenesis. Palmitoleate, pentadecanoate, and palmitate influenced the osteoblastogenesis of MC3T3-E1 cells through miR-92b-3p. It is proposed that miR-92b-3p mediates the effect of bone marrow fatty acids on osteoblast differentiation in the early stages of osteoporosis, providing potential molecular insights for its treatment.