Collagen type V a2 (COL5A2) is decreased in steroid-induced necrosis of the femoral head.

Collagen is essential for bone adhesion and formation. In the present study, proteomic analysis suggested that collagen type V a2 (COL5A2) was significantly decreased in the necrotic area of patients with steroid-induced necrosis of the femoral head (ONFH). In vitro, the effects of methylprednisolone (MP) on the proliferation and differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs) were investigated. The expression of the osteogenic-related proteins, Runx2, alkaline phosphatase (ALP), osteocalcin (OC) and COL5A2 was significantly downregulated post-MP treatment. In vivo analyses revealed that post-MP treatment, rats showed typical signs of ONFH by micro-CT scanning and hematoxylin and eosin (H&E) staining. Immunohistochemical staining demonstrated that the expression of COL5A2 and vascular endothelial growth factor (VEGF) was significantly decreased post-MP treatment. In conclusion, the expression COL5A2 was lower in patients with steroid-induced ONFH, hence COL5A2 may be a promising therapeutic target for steroid induced ONFH treatment.