Abstract: Objective To investigate the effect of exendin-4 on the expression of monocyte chemoattractant protein-1 (MCP-1)
and fibronectin (FN) in rat glomerular mesangial cells in vitro. Methods Rat glomerular mesangial cells were divided into 5
groups, namely control group, tumor necrosis factor-α (TNF-α) group (10 ng/ml), TNF-α (10 ng/ml)+E1 (1 nmol/L exendin-4)
group, TNF-α (10 ng/ml) + E5 (5 nmol/L exendin-4) group, and TNF-α (10 ng/ml) + E10 (10 nmol/L exendin-4) group. After
cultured 24 h or 48 h, RNA were extracted to determine the expression of MCP-1 with real-time PCR, the supernatant were
collected to determine the expression of MCP-1 and FN with ELISA. Results Compared with control group, the cells treated
with TNF-α for 24 h showed significantly increase the expression of MCP-1 and FN (P<0.01), exendin-4 significantly reduced
the expression of MCP-1 and FN in TNF-α+E5 group and TNF-α+E10 group (P<0.05). After 48 h incubation, the expression of
MCP-1 and FN increased significantly in TNF-α group (P<0.01), which was lowered by exendin-4 in TNF-α+E1,TNF-α+E5 and
TNF-α+E10 groups (P<0.05). Conclusion Exendin-4 has an intrinsic capability to concentration- and time-dependently inhibit
TNF-α-induced expression of MCP-1 and FN in rat mesangial cells, suggesting the beneficial effect of exendin-4 in preventing
and treating diabetic nephropathy.