MicroRNA-200a-3p accelerates the progression of osteoporosis by targeting glutaminase to inhibit osteogenic differentiation of bone marrow mesenchymal stem cells

Abstract

To uncover the role of microRNA-200a-3p in regulating osteogenic differentiation of MSCs via targeting glutaminase, thus influencing the progression of OP. Serum level of microRNA-200a-3p in OP patients and healthy controls was determined by qRT-PCR. MicroRNA-200a-3p level in MSCs undergoing osteogenic differentiation for different days was examined as well. ALP activity, calcification nodules and relative levels of Bglap, Runx2 and OPN in MSCs overexpressing microRNA-200a-3p undergoing osteogenic differentiation were detected. Relative l-glutaminase uptake in MSCs undergoing osteogenic differentiation for different days was determined. After transfection of si-GLS in MSCs undergoing osteogenic differentiation, l-glutaminase uptake, ALP activity and relative levels of Bglap, Runx2 and OPN were detected. The potential binding relationship between microRNA-200a-3p and GLS was tested by dual-luciferase reporter gene assay. Finally, rescue experiments were conducted to elucidate the role of microRNA-200a-3p/GLS in osteogenic differentiation of MSCs. MicroRNA-200a-3p level was higher in serum of OP patients relative to controls. Its level in MSCs gradually decreased with the prolongation of osteogenic differentiation. Overexpression of microRNA-200a-3p reduced cell viability, ALP activity, number and volume of calcification nodule. The mRNA levels of Bglap, Runx2 and OPN were downregulated by overexpressed microRNA-200a-3p. The cell viability, ALP activity, number and volume of calcification nodule were reduced when microRNA-200a-3p was knocked down. The mRNA levels of Bglap, Runx2 and OPN were upregulated when transfected microRNA-200a-3p inhibitor. l-glutaminase uptake increased with the prolongation of osteogenic differentiation in MSCs. Knockdown of GLS attenuated l-glutaminase uptake and ALP activity, as well as downregulated Bglap, Runx2 and OPN. Besides, GLS was verified to directly bind to microRNA-200a-3p. GLS overexpression reversed the inhibitory effects of overexpressed microRNA-200a-3p on osteogenic differentiation of MSCs. MicroRNA-200a-3p suppresses osteogenic differentiation of MSCs via targeting glutaminase, thereafter accelerating the progression of OP.

Keywords: Glutaminase; MicroRNA-200a-3p; Osteogenic differentiation; Osteoporosis.