Influence of adiponectin on expression of monocyte chemotactic protein-1 induced by high glucose in rat proximal renal tubular epithelial cells

Abstract

Objective To observe the effect of adiponectin on the secretion of monocyte chemotactic protein(MCP-1) in rat proximal renal tubular epithelial cell(NRK-52E) in vitro. Methods Using DMEM medium with different concentrations of glucose and adiponectin to culture rat proximal tubular epithelial cells in vitro in five groups(four samples in each group, the experiment were repeated for 4 times): group A: DMEM medium with 5 mmol/L of glucose as control group; group B: DMEM medium with 30 mmol/L of glucose; group C: DMEM medium with 30 mmol/L of glucose and 1 mg/L of recombinant adiponectin; group D: DMEM medium with 30 mmol/L of glucose medium and 5 mg/L of recombinant adiponectin; group E: DMEM medium with 30 mmol/L of glucose medium and 10 mg/L of recombinant adiponectin. The reverse transcription time-polymerase chain reaction(RT-PCR) and Western blot methods were used to detect the expression of MCP-1 mRNA and protein in the 5 groups. The results were compared among the 5 groups. The t test was used when compared between two groups and analysis of variance was used in the comparison among multi-groups. Results The expression of MCP-1 mRNA in group A was 0.247±0.005, it was 0.691±0.009 in group B and was significantly higher than that in group A(t=72.03, P 0.05); it was 0.253±0.011 in group E and was similar with group A. There was significant differences in expression of MCP-1 mRNA among the groups with different concentrations of adiponectin(F=37.15, P<0.05). The expression of MCP-1 protein in group A was 10.25±0.03, it was 58.47±0.02 in group B and was significantly higher than that in group A (t=35.21, P<0.01); it was 35.86±0.05 in group C and was significantly lower than that in group B(t=48.26.21, P<0.05); it was 25.63±0.06 in group D and was significantly lower than that in group B(t=32.34, P<0.01); it was 21.53±0.03 in group E and was significantly lower than that in group B(F=42.26, P<0.05) and significantly higher than that in group A (t=64.28, P<0.01). There was significant differences in expression of MCP-1 protein among the groups with different concentrations of adiponectin(F=53.15, P<0.05). Conclusion Adiponectin could inhibit the highly expressed MCP-1 mRNA and protein induced by high glucose in rat proximal tubular epithelial cells in vitro in a dose-dependent manner. Key words: Diabetic nephropathies; Rats; Monocyte chemotactic protein 1; Adiponectin; Proximal renal tubular epithelial cell