Amelioration of Renal Inflammation, Endoplasmic Reticulum Stress and Apoptosis Underlies the Protective Effect of Low Dosage of Atorvastatin in Gentamicin-Induced Nephrotoxicity.

Krit Jaikumkao,Varanuj Chatsudthipong,Phatchawan Arjinajarn,Anusorn Lungkaphin,Anchalee Pongchaidecha,Keerati Wanchai,La-Ongdao Thongnak,Nipon Chattipakorn,Demetrios G Vavvas

doi:10.1371/journal.pone.0164528

Krit Jaikumkao, Varanuj Chatsudthipong + Show 7 more

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https://doi.org/10.1371/journal.pone.0164528

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Abstract

Gentamicin is a commonly used aminoglycoside antibiotic. However, its therapeutic use is limited by its nephrotoxicity. The mechanisms of gentamicin-induced nephrotoxicity are principally from renal inflammation and oxidative stress. Since atorvastatin, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, exerts lipid-lowering effects, antioxidant, anti-inflammatory as well as anti-apoptotic effects, this study aimed to investigate the protective effects of atorvastatin against gentamicin-induced nephrotoxicity. Male Sprague Dawley rats were used and nephrotoxicity was induced by intraperitoneal injection of gentamicin, 100 mg/kg/day, for 15 days. Atorvastatin, 10 mg/kg/day, was administered by orally gavage 30 min before gentamicin injection on day 1 to 15 (pretreatment) or on day 10 to15 (delayed treatment). For only atorvastatin treatment group, it was given on day 1 to 15. At the end of the experiment, kidney weight, blood urea nitrogen and serum creatinine as well as renal inflammation (NF-κB, TNFαR1, IL-6 and iNOS), renal fibrosis (TGFβ1), ER stress (calpain, GRP78, CHOP, and caspase 12) and apoptotic markers (cleaved caspase-3, Bax, and Bcl-2) as well as TUNEL assay were determined. Gentamicin-induced nephrotoxicity was confirmed by marked elevations in serum urea and creatinine, kidney hypertrophy, renal inflammation, fibrosis, ER stress and apoptosis and attenuation of creatinine clearance. Atorvastatin pre and delayed treatment significantly improved renal function and decreased renal NF-κB, TNFαR1, IL-6, iNOS and TGFβ1 expressions. They also attenuated calpain, GRP78, CHOP, caspase 12, Bax, and increased Bcl-2 expressions in gentamicin-treated rat. These results indicate that atorvastatin treatment could attenuate gentamicin-induced nephrotoxicity in rats, substantiated by the reduction of inflammation, ER stress and apoptosis. The effect of atorvastatin in protecting from renal damage induced by gentamicin seems to be more effective when it beginning given along with gentamicin or pretreatment.

Highlights

Nephrotoxicity is an adverse effect of gentamicin treatment, despite its positive therapeutic activity against both gram-positive and gram negative bacteria [1,2,3]
Pharm.Org, Thailand) with the volume of 700–800 μl for 15 days; (3) the atorvastatin group, Ator (Lek Pharmaceuticals d.d, Slovenia) dissolved in 500 μl of 0.9% normal saline solution at dose of 10 mg/kg/day was administered by gavage feeding once a day on day 1 to 15; (4) the atorvastatin pretreatment (Pre) group, Ator was administered by gavage 30 min before gentamicin treatment for 15 days; and (5) atorvastatin delayed treatment (Delayed) group, gentamicin was injected every day for 15 days and Ator was administered on days 10 to 15 by gavage 30 min before the gentamicin treatment
The apparent increase in serum BUN and creatinine levels and a significant decrease in creatinine clearance in gentamicin-treated group compared with the control or atorvastatin groups (P < 0.05) (Fig 2A, 2B and 2C) indicated that renal function impairment was induced by gentamicin treatment

Summary

Introduction

Nephrotoxicity is an adverse effect of gentamicin treatment, despite its positive therapeutic activity against both gram-positive and gram negative bacteria [1,2,3]. Renal inflammation is demonstrated by an infiltration of inflammatory cells such as monocytes and macrophages and the subsequent release of proinflammatory cytokines and activation of NF-κB in response to oxidative stress [1,3]. The accumulation of gentamicin in the endoplasmic reticulum (ER) may induce endoplasmic reticulum (ER) stress which activates the unfolded protein response (UPR) and cell cycle arrest [9]. When unfolded proteins accumulate, the ER chaperone immunoglobulin heavy-chain-binding protein (BiP; known as GRP78) expression is increased and dissociates from the ER receptors, leading to their activation and triggering the ER stress response [11]. The use of several agents with anti-oxidant, anti-inflammation and anti-apoptosis activities and ER stress inhibition or an agent that posses multiple mechanisms of action may successfully prevent or ameliorate gentamicin-induced nephrotoxicity

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