CR6-interacting factor-1 contributes to osteoclastogenesis by inducing receptor activator of nuclear factor κB ligand after radiation

Figure 2 Overexpression of CR6-interacting factor-1 in bone marrow mesenchymal stem/stromal cells increases receptor activator of nuclear factor κB ligand secretion and osteoclastogenesis. A: Western blot analysis of CR6-interacting factor-1 (Crif1) expression in mouse bone marrow mesenchymal stem/stromal cells (BM-MSCs). Mouse BM-MSCs were transfected with a Crif1 lentiviral overexpression vector; B: Real-time quantitative polymerase chain reaction analysis of receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) mRNA expression in BM-MSCs and Crif1-overexpressing BM-MSCs. BM-MSCs and Crif1-overexpressing BM-MSCs were cocultured with RAW264.7, respectively; C: RANKL/OPG ratio based on real-time quantitative polymerase chain reaction results; D: Enzyme linked immunosorbent assay analysis of RANKL protein levels in coculture supernatant medium; E: Enzyme linked immunosorbent assay analysis of OPG protein levels in coculture supernatant medium; F: RANKL/OPG ratio in coculture supernatant medium; G: Tartrate-resistant acid phosphatase staining of RAW264.7 cells after 7 d of coculture; H: Average number of tartrate-resistant acid phosphatase-positive cells/well (arrow) from RAW264.7 cells in coculture. ^aP < 0.05, ^bP < 0.01, and the bars represent the mean ± SD. OPG: Osteoprotegerin; RANKL: Receptor activator of nuclear factor κB ligand; Crif1: CR6-interacting factor-1; BM-MSCs: Bone marrow mesenchymal stem/stromal cells; BM-MSCs-OV: Crif1-overexpressing BM-MSCs.