This study aimed to examine the protective effects of
aliskiren on
gentamicin-induced nephropathy. Rats were injected with
gentamicin (100 mg/kg per day) for 14 days.
Aliskiren was infused for two weeks. Human proximal tubular epithelial cell lines (HK-2) were cultured with
gentamicin in the absence or presence of
aliskiren. Inflammatory profibrotic and apoptotic markers were evaluated in vivo and in vitro.
Aliskiren treatment attenuated the decreased
creatinine clearance, increased fractional
sodium excretion, glomerulosclerosis and tubulointerstitial
fibrosis and counteracted the increased ED-1 expression in
gentamicin-treated rats. The levels of inflammatory
cytokines (TNF-α, IL-1β and IFN-γ) and adhesion molecules (MCP-1, ICAM-1 and VCAM-1) increased in the
gentamicin-treated kidneys. These changes were restored by
aliskiren co-treatment.
Aliskiren effectively reversed
transforming growth factor-β-induced fibrotic responses such as induction of α-smooth muscle actin in
gentamicin-treated rat kidneys. Along with these changes,
aliskiren also attenuated the increase in nuclear factor κB and phosphorylated
extracellular signal-regulated kinase (pERK 1/2) levels in HK-2 cells cultured with
gentamicin. In addition,
aliskiren decreased the number of TUNEL-positive nuclei and reduced the expression of proapoptotic markers in
gentamicin-treated HK-2 cells. These findings suggest that
aliskiren attenuates
gentamicin-induced nephropathy by suppression of inflammatory, profibrotic and apoptotic factors through inhibition of the nuclear factor κB, Smads and
mitogen-activated protein kinase signaling pathways.