Tacrolimus inhibits Puromycin induced injury of podocytes by stabilizing the expression and distribution of podocin

Objective To investigate the effect of Puromycin(PAN) and Tacrolimus(FK506) on the expre-ssion of podocin in podocytes, and discuss the mechanism of FK506 in improving proteinuria caused by the damage of glomerular podocytes. Methods Mouse podocyte were cultured and divided into 3 groups, which were control group, PAN group and FK506 group, respectively.The changes of each group after 8 hours, 24 hours and 48 hours of treatment were detected by using phase-contrast microscope, and the expression and distribution of protein and mRNA were tested by adopting Western blot, quantitative real-time PCR and immunofluorescence technique. Results Compared with the control group(8.54±0.25, 8.27±0.07, 7.45±0.13) at each time point(8 hours, 24 hours and 48 hours), the soma size of the PAN group(6.41±0.22, 4.96±0.09, 3.76±0.16) was reduced.But in the FK506 group(7.67±0.06, 6.62±0.04, 5.57±0.27), it was increased at each time point(8 hours, 24 hours and 48 hours) compared with the PAN group.The podocytic process and the intercellular connection disappeared, and the distribution was significantly scattered.The mRNA (0.87±0.15, 0.78±0.15, 0.58±0.12)and protein (0.82±0.02, 0.62±0.03, 0.50±0.02) expressions of podocin increased in FK506 group and mRNA(0.63±0.12, 0.56±0.01, 0.48±0.02), protein(0.71±0.03, 0.46±0.01, 0.34±0.02) were observably reduced in PAN group at each time point(8 hours, 24 hours and 48 hours) and showed abnormal distribution in PAN group, compared with the control group[podocin mRNA(1.22±0.15, 1.18±0.06, 0.87±0.30), protein(0.86±0.03, 0.87±0.03, 0.61±0.07)]. Conclusions PAN attenuates the mRNA and protein expression of podocin by damaging podocytes, inversely, while FK506 protects potocyte injury by stabilizing the mRNA and protein expression of podocin, which maybe involve inhibition of proteinuria.It can be used as a target for the study and treatment of kidney diseases. Key words: Podocytes; Tacrolimus; Puromycin; Podocin