A ROS/GAS5/SIRT1 reinforcing feedback promotes oxidative stress-induced adipogenesis in bone marrow-derived mesenchymal stem cells during osteoporosis

BACKGROUND: LincGAS5 have been reported to regulate the progression of osteoporosis (OP). However, the relationship between LincGAS5 and reactive oxygen species (ROS) in osteoporosis were still unclear. METHODS: Bilateral ovariectomy (OVX) rat were established as OP model and verified by the Micro-computed tomography. The ROS level of BMSCs derived from OVX and control rat were detected by Immunofluorescence (IF) and flow cytometry. The role of GAS5, miR-23b-3p and SIRT1 on the osteogenic differentiation were dectected by ARS saining and ALP staining, while the The Oil Red O staining and flow cytometry (FCM) were hired to determine adipogenic differentiation of BMSCs under different treatment. The expression of GAS5,miR-23b-3p and SIRT1 in BMSCs was detected by RT-qPCR and the correlation among them was analyzed. In addition, Luciferase activity was used to detect whether miR-23b-3p combined with GAS5 and SIRT1 in OP mice BMSCs. RESULTS: We established the OVX rat model and found higher ROS level in BMSCs isolated from OVX rats. Meanwhile, GAS5 was down-regulated by ROS and remarkably lowly expressed in OVX rat comparing with the negative control. We confirmed GAS5 inhibited adipogenesis and promoted osteoporosis progression. Mechanically, GAS5 bound with miR-23b-3p and suppressed its biological function. We also identified that miR-23b-3p bound with Sirtuin 1 (SIRT1) and decreased its stability. Furthermore, SIRT1 suppressed ROS production in BMSCs, which in turn un-regulated GAS5 expression through ROS-GAS5 axis. CONCLUSION: We identified a negative feedback loop, ROS-GAS5-SIRT1, in osteoporosis progression. Our findings provided potential targets and biomarkers for osteoporosis prevention and treatment.