ToxSci Advance Access originally published online on January 27, 2008
Toxicological Sciences 2008 102(2):433-443; doi:10.1093/toxsci/kfn008
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Role of Tissue Kallikrein in Prevention and Recovery of Gentamicin-Induced Renal Injury
* Department of Biology, Charleston Southern University, 9200 University Boulevard, Charleston, South Carolina 29406
Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, 171 Ashley Avenue, South Carolina 29425
1 To whom correspondence should be addressed. Fax: 843-863-7290. E-mail: gbledsoe{at}csuniv.edu.
Received November 14, 2007; accepted December 20, 2007
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Abstract |
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Gentamicin is an aminoglycoside antibiotic that induces severe nephrotoxicity and acute renal failure. In the current project, we investigated the protective effects of tissue kallikrein (TK) protein administration (1 µg/h via osmotic minipumps) on kidney damage, apoptosis, and inflammation both during and after a 10-day regimen of gentamicin (80 mg/kg body weight/day sc) in Sprague-Dawley rats. TK infusion during gentamicin treatment significantly attenuated drug-induced renal dysfunction, cortical damage, and apoptosis. Moreover, TK reduced inflammatory cell accumulation in conjunction with diminished superoxide production and decreased expression of tumor necrosis factor-
, monocyte chemoattractant protein-1, and intercellular adhesion molecule-1. The protective effects of TK were blocked by coinfusion of icatibant (1.3 µg/h), indicating a kinin B2 receptor–mediated signaling event. After cessation of gentamicin treatment, TK infusion for 2 weeks completely restored kidney histology and morphology comparable to that of saline-treated animals. Furthermore, TK reduced gentamicin-induced renal dysfunction and fibrosis as evidenced by decreased myofibroblast and collagen accumulation in the kidney. In vitro, gentamicin increased the number of apoptotic cells and caspase-3 activity, but decreased phosphorylation of the prosurvival kinase Akt, in immortalized rat proximal tubular cells; addition of TK and bradykinin prevented these effects. In conclusion, our findings indicate that kallikrein/kinin prevents and promotes recovery of gentamicin-induced renal injury by inhibiting apoptosis, inflammatory cell recruitment, and fibrotic lesions through suppression of oxidative stress and proinflammatory mediator expression in animals during and after gentamicin treatment.
Key Words: aminoglycoside; apoptosis; fibrosis; inflammation; kidney.