CCL2 and type 2 diabetes mellitus: Furthermore, both western blotting (Figure 3(d)) and immunohistochemistry (Figure 3(e)) confirmed that SCFAs reversed the T2D-induced downregulation of GPR43 and upregulation of β-arrestin-2 and inhibited p-NF-κBp65 and MCP-1 expression, suggesting that SCFAs have a protective effect on DN by regulating GPR43-β-arrestin-2 and inhibiting the activation of NF-κB signaling.