Abstract:

【Abstract】  Objective: To investigate the effect of fasudil (a specific Rho-kinase inhibitor) on angiotensin (Ang) II-induced autophagy in podocytes. Methodology: The conditionally immortalized human podocytes (AB8/13) were incubated with various concentrations of AngII (10-8 to 10-6 mol/l) for 24h or  with 10-7 mol/lAng II for  different times (0, 6, 12, 24 and 36 hours), together  with or without autophagy inhibitor 3-methyladenine (3-MA) and various concentrations of fasudil (10-8 to 10-6 mol/l) in vitro. The protein expression of LC3B and Beclin-1 were detected by immunofluorescence and western blotting. Results: The proteins expression of LC3B and Beclin-1 were up-regulated significantly by Ang II in a dose- and time- dependent manner. The optimal concentration of Ang II was 10-7mol/l and the optimal time was at 24h in which AngII enhanced LC3B and Beclin-1 protein expression to the maximum . The stimulation of podocytes with Ang II increased LC3B and Beclin-1 expression that was prevented by 3-MA. The expression enhancement of LC3B and Beclin-1 by AngII were reduced  significantly by fasudil in a dose- dependent manner, although fasudil alone does not induce autophagy. The optimal inhibitory  concentration of fasudial was 10-7mol/l.  Conclusion: The autophagy of podocytes can be induced by Ang II and inhibited  by fasudil, which suggests that Rho-kinase pathway may mediate Ang II induced the autophagy of podocytes.

Key words: Angiotensin II, autophagy, Rho-kinase,  podocytes, 3-methyladenine