View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector http://www.kidney-international.org original article & 2011 International Society of Nephrology Amelioration of cisplatin nephrotoxicity by genetic or pharmacologic blockade of prostaglandin synthesis Zhanjun Jia1,2, Ningning Wang1,2, Toshinori Aoyagi1, Haiping Wang1, Haiying Liu1 and Tianxin Yang1 1Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA Nephrotoxicity is a common complication of cisplatin Cis-diamminedichloroplatinum (cisplatin), an inorganic chemotherapy that limits its clinical use. Here, we determined molecule, is one of the simplest and most effective whether arachidonic acid metabolism has a role in the chemotherapeutic agents and is widely used for treatment pathogenesis of cisplatin nephrotoxicity in mice. Three days of various types of solid tumors, including testicular, ovarian, following cisplatin injection, wild-type mice displayed renal head, neck, and uterine cervical carcinoma and nonsmall cell functional and structural abnormalities consistent with lung carcinoma.1–4 Unfortunately, its clinical use is limited by nephrotoxicity accompanied by elevated circulating and severe side effects in normal tissues. Nephrotoxicity is a renal levels of TNF-a and renal levels of IL-1b,subunitsof frequent adverse effect with about 25–35% patients displaying NADPH oxidase, thiobarbituric acid-reactive substances, and decline of renal function after a single dose of cisplatin.5 PGE2. These indices of kidney injury, inflammation, oxidative Despite intensive investigation, the mechanisms underlying stress, and arachidonate metabolism were all diminished in cisplatin-induced nephrotoxicity are not fully understood. microsomal prostaglandin E synthase-1 (mPGES-1) null mice; After administration, cisplatin is taken up in renal a phenotype recapitulated by treatment of wild-type mice tubular cells at high concentrations, leading to tubular with the COX-2 inhibitor celecoxib. Following cisplatin injury and cell death. The signaling mechanisms res- administration, there was paralleled induction of COX-2 and ponsible for cisplatin-induced cytotoxicity appear to be mPGES-1 in renal parenchymal cells. Interestingly, mPGES-1 multifactorial, involving inflammation, oxidative stress, and null mice were not protected from acute kidney injury caused caspase.4 by ischemia–reperfusion or endotoxin. Hence, our results Prostaglandin E2 (PGE2), a major product of arachidonic suggest the activation of COX-2/mPGES-1 pathway in renal acid (AA) metabolism, has an established role in mediating 6 parenchymal cells may selectively mediate cisplatin-induced pain and inflammatory responses. The biosynthesis of PGE2 renal injury. This may offer a novel therapeutic target for requires three sequential steps of the cyclooxygenase (COX) management of the adverse effect of cisplatin chemotherapy. pathway: the release of AA from membrane glyceropho- Kidney International (2011) 79, 77–88; doi:10.1038/ki.2010.331; spholipids by phospholipase A2, conversion of AA to the published online 15 September 2010 unstable intermediate PGH2 by COX-1 or COX-2, and finally KEYWORDS: cisplatin; cyclooxygenase-2; cytokines; microsomal isomerization of PGH2 to PGE2 by prostaglandin E synthase prostaglandin E synthase-1; nephrotoxicity (PGES).7,8 To date, at least three major forms of PGES have been cloned and characterized: membrane-associated PGES (mPGES)-1, mPGES-2, and cytosolic PGES.8 mPGES-1 is a 16-kDa membrane-bound protein encoded by a 2.0-kb transcript. Similar to COX-2, mPGES-1 expression in inflammatory cells is highly inducible in macrophages in vitro9,10 and in the spleen and lung in vivo11–13 in response to proinflammatory stimuli. Moreover, mPGES-1-deficient mice exhibit blunted pain and inflammatory responses.9,14 mPGES-1 has also be implicated to have a key role in a 15 Correspondence: Tianxin Yang, Department of Internal Medicine, University number of chronic inflammatory diseases. Owing to the of Utah and VA Medical Center, 30 N 1900 E, Room 4R312, Salt Lake City, cardiovascular consequences of COX-2 inhibitors, mPGES-1 Utah 84132, USA. E-mail: [email protected] has been considered as a promising target for the next 2These authors contributed equally to this work. generation of analgesic drugs. Here, we describe a novel role Received 6 September 2009; revised 11 June 2010; accepted 29 June of mPGES-1 and COX-2 in the pathogenesis of cisplatin 2010; published online 15 September 2010 nephrotoxicity. Kidney International (2011) 79, 77–88 77 original article Z Jia et al.: mPGES-1 and cisplatin nephrotoxicity RESULTS were subjected to cisplatin treatment and the severity of renal mPGES-1 deletion attenuates cisplatin-induced renal dysfunction was reflected by blood urine nitrogen (BUN) and dysfunction and tubular damage plasma creatinine (Cr). At baseline, the values of BUN and To investigate the role of mPGES-1 in cisplatin nephro- plasma Cr were similar between the genotypes. Cisplatin toxicity, mPGES-1 wild-type (WT) and knockout (KO) mice treatment remarkably elevated BUN and plasma Cr in WT mice. These increases were attenuated by 80% for plasma Control Cr and 38% for BUN in the KO mice (Figure 1). Grossly, the Cisplatin degree of kidney swelling secondary to cisplatin-induced P <0.01 P <0.01 renal injury appeared similar between the genotypes 200 (Figure 2a) as confirmed by the similar increase in kidney wet weight (WT: 0.283±0.027 vs 0.162±0.013 g, Po0.05; 150 P<0.01 KO: 0.279±0.023 vs 0.171±0.015 g, Po0.05). However, 100 following cisplatin treatment, the WT kidney became pale and ischemic contrasting to the normal appearance of the KO BUN (mg/dl) 50 kidney (Figure 2a). Microscopically, at baseline, there was no 0 obvious difference in the renal morphology between the WT KO genotypes. While, following cisplatin treatment, WT mice displayed severe renal pathological changes characterized 2.5 P <0.01 P <0.01 by distortion of the overall renal morphology, dilation 2 of renal tubules, and appearance of protein cast, most of 1.5 which were significantly attenuated in the KO mice (Figure 2b). The difference in the renal injury between the geno- 1 P<0.05 types was further reflected by the semiquantitative histolo- 0.5 gical damage score (Figure 2c). Acute renal failure is often Plasma Cr (mg/dl) 0 associated to fluid retention, leading to a fall in hematocrit. WT KO We found that hematocrit significantly decreased in WT Figure 1 | Assessment of renal function after cisplatin treatment. mice after cisplatin treatment and this decrease was less in Blood urine nitrogen (BUN) (a) and plasma creatinine (Cr) (b)in the KO mice (Figure 3a). Interestingly, the body weight membrane-associated prostaglandin E synthase-1 (mPGES-1) þ / þ loss, which reflects the general or gastrointestinal toxicity and À/À mice at 72 h following treatment with vehicle or cisplatin. Wild-type (WT)/vehicle: N ¼ 6; knockout (KO)/vehicle: N ¼ 6; WT/ of cisplatin, was not different between the genotypes cisplatin: N ¼ 16; KO/cisplatin: N ¼ 16. Data are mean±s.e. (Figure 3b). WT KO WT control WT cisplatin Control KO control KO cisplatin P <0.01 4 3.5 3 Cisplatin 2.5 2 1.5 damage 1 0.5 Score of tubular 0 WT KO Figure 2 | Morphological analysis of cisplatin-induced renal injury in membrane-associated prostaglandin E synthase-1 (mPGES-1) þ / þ and À/À mice. (a) Gross kidney appearance. (b) Hematoxylin and eosin staining (magnification: Â 200 shown) of renal cortex. (c) Renal injury score in cisplatin-treated mPGES-1 þ / þ and À/À mice. Wild-type (WT)/vehicle: N ¼ 6; knockout (KO)/vehicle: N ¼ 6; WT/cisplatin: N ¼ 9; KO/cisplatin: N ¼ 10. N ¼ 9 per group. Data are mean±s.e. 78 Kidney International (2011) 79, 77–88 Z Jia et al.: mPGES-1 and cisplatin nephrotoxicity original article mPGES-1 deletion attenuates cisplatin-induced process.16 Therefore, our emphasis was placed on analysis of renal expression of cytokines the activation of TNF-a in response to cisplatin treatment. Activation of proinflammatory cytokine release is well known Immunoblotting demonstrated a marked increase in the total 16 to contribute to cisplatin nephrotoxicity. In particular, protein abundance of renal TNF-a in cisplatin-treated WT tumor necrosis factor-a (TNF-a) is shown to have a central mice and this increase was significantly attenuated in the role in the activation of the cytokine response in this disease KO mice (Figure 4a). This result was confirmed at mRNA level using quantitative reverse transcriptase (qRT)-PCR Control P <0.01 (Figure 4b). Moreover, circulating TNF-a levels were Cisplatin measured by using enzyme-linked immunosorbent assay. 60 P<0.01 P<0.05 Consistent with the gene expression data, the increases in 55 plasma TNF-a concentrations were less in the KO mice than 50 in WT controls (Figure 4c). Renal interleukin (IL)-1b mRNA 45 Hct (%) expression exhibited similar patterns of changes as TNF-a 40 (Figure 4d). 35 WT KO mPGES-1 deletion attenuates cisplatin-induced ROS 24 h 48 h 72 h production 0 In addition to inflammation, oxidative stress is another –1 important factor involved in the pathogenesis of cisplatin nephrotoxicity. Therefore, we evaluated the effect of mPGES- –2 1 deletion on cisplatin-induced oxidative stress. The level of –3 kidney thiobarbituric acid-reactive substances (TBARS), an index of reactive oxygen species (ROS) generation, signifi- –4 WT KO cantly increased in WT mice after cisplatin treatment Body weight decrease –5 compared with day 0 (g) and this increase was completely abolished in the KO mice –6 (Figure 5a). The increased ROS generation in cisplatin- treated WT mice was associated with elevated renal expres- Figure 3 | Effects of cisplatin-treatment on hematocrit (Hct) and phox phox body weight. Changes in hematocrit (Hct) (a) and body weight (b) sion of p47 (Figure 5b) and gp91 (Figure 5c), the two in membrane-associated prostaglandin E synthase-1 (mPGES-1) major subunits of NADPH oxidase, but not NOX-1 (Figure þ / þ and À/À mice following treatment with vehicle or cisplatin.