Vaspin deficiency failed to promote the proliferation of BMSCs in osteoarthritis.

Abstract

The aim of this study was to estimate the possible role of vaspin in the proliferation of bone mesenchymal stem cells (BMSCs) and its molecular mechanisms in the bone marrow microenvironment of osteoarthritis (OA). This study included 15 non-obese elderly patients with severe knee OA and 15 non-obese controls with femoral neck fracture. Patients all underwent hip or knee arthroplasty surgery to restore joint shape and function. Bone marrow samples were taken during surgery to estimate vaspin and transforming growth factor (TGF)-β1 levels by enzyme-linked immunosorbent assay and to observe the effect of vaspin on BMSCs proliferation by Cell Counting Kit-8. Real-time polymerase chain reaction and western blot were performed to evaluate the effect of vaspin on the genes and proteins of Akt involved in the PI3K/AKT signaling pathway. Bone marrow vaspin levels were significantly lower in OA patients compared to controls (P=.03). Furthermore, we found a significant correlation between vaspin and TGF-β1 concentrations in bone marrow (r=.60, P<.01). In addition, the in vitro studies indicated the proliferation of BMSCs was significantly promoted when the vaspin treatment concentration was 150ng/mL (P<.01). Meanwhile, we found that the Akt messenger RNA and pAkt protein levels in BMSCs were increased after vaspin treatment (P<.05). The findings of this study suggest there was abnormal expression of vaspin in OA bone marrow microenvironment, and vaspin likely had a mediator role in the proliferation of BMSCs, which may work by promoting the activation of the PI3K/AKT signaling pathway.