A role of p38 mitogen-activated protein kinase in regulating expression of Peroxisome proliferator-activated receptors-γ in rat mesangial cells

Objective To investigate the relationship between p38MAPK and PPAR-γ,and to study the role of p38MAPK and PPAR-γ for diabetic nephropathy. Methods The expression of p38MAPK protein and PPAR-γ mRNA was investigated in rat mesangial cells line HBZY-1 that was incubated respectively with 25 mmol/L glucose,100 nmol/L insulin,100 μmol/L H_2O_2 and 100 mg/L AGEs. The relationship between p38MAPK and PPAR-γ expression was studied by using SB203580,a specific inhibitor of p38MAPK. Results p38MAPK had significantly higher expression,while the expression of PPAR-γ was significantly decreased in rat mesangial cells line HBZY-1 incubated with 25 mmol/L glucose,100 nmol/L insulin,100 μmol/L H_ 2 O_ 2 and 100 mg/L AGEs respectively. PPAR-γ activity was significantly reduced when p38MAPK was inhibited by SB203580. Conclusion p38MAPK is involved in development of diabetic nephropathy and may antagonize the expression of PPAR-γ. PPAR-γ activity might protect the function of kidney.