Induction of C-Mip by IL-17 Plays an Important Role in Adriamycin-Induced Podocyte Damage.

BACKGROUND/AIMS: Although the disturbance of T lymphocyte and glomerular podocyte exerts a crucial function in the pathogenesis of proteinuria, the potential link is still unclear.

METHODS

The balance of Treg and Th17 cells, and the expression of IL-17/IL-17R and c-mip were investigated in adrimycin-induced nephropathy (AN) mice. The effect and mechanism of IL-17 on podocyte were explored in cultured podocytes.

RESULTS

The proportion of Th17 cells in peripheral blood mononuclear cells, the amount of IL-17 in serum and kidney cortical homogenates, and the expression of IL-17R and c-mip in glomerular podocyte were increased obviously in AN mice. In cultured podocytes, recombinant IL-17 led to an induction of apoptosis and cytoskeletal disorganization, an overproduction of c-mip while down-regulation of phosphor-nephrin, and an increased binding of c-mip to NF-κB/RelA. Silence of c-mip prevented podocyte apoptosis and reduction of phosphor-nephrin by prompting nuclear translocation of NF-κB/RelA in IL-17 treated cells. Persistent activation of NF-κB up-regulated pro-survival protein Bcl-2 and decreased podocyte apoptosis, but had no effect on phosphor-nephrin level.

CONCLUSION

These findings demonstrated that induction of IL-17 released by Th17 cells plays a key role in podocytopathy most likely through down-regulation of phosphor-nephrin and Bcl-2 level via overproduction of c-mip.