CCL2 and obesity due to melanocortin 4 receptor deficiency: In serum and synovial fluid, eight obesity-induced inflammatory cytokines (VEGF, MIP-1α, MIP-2, IP-10, IL-1α, TNF-α, MCP-1, and leptin) and LPS were increased in the DIO-KOA group compared with the control group (Figure 3).