Vascular endothelial growth factor expression and regulation of murine collagen-induced arthritis

Objective The expression and function of the angiogenic factor,vascular endothelial growth factor (VEGF) during the evolution of type Ⅱ collagen induced arthritis (CIA) were examined.Methods Passive immunization was taken to induce CIA and arthritis index was evaluated.The VEGF and vWF proteins were measured by ELISA.The VEGF and vWF were visualized by immunohistochemistry.The expression of VEGF mRNA was analyzed by RT PCR and Southern blotting.Results The VEGF and vWF levels reached a maximum on day 4 after the onset of arthritis and then gradually declined,neovascularization thus correlated temporally with both VEGF expression and footpad swelling.The VEGF transcripts,especially the 279 bp and 304 bp forms,were constitutively expressied in joint tissues.Conclusion The VEGF plays a crucial role during an early stage of arthritis development,affecting both neovascularization and the progression of experimentally induced synovitis.