FP270 GENDER DIFFERENCE IN CISPLATIN-INDUCED NEPHROTOXICITY AND THE PROTECTIVE EFFECT OF STARCATION Min Jung Kong 1 , Jee In Kim 2 , Kwon Moo Park 1 1 School of Medicine, Kyungpook National University, Daegu, South Korea, Republic of Korea and 2 College of Medicine, Keimyung University, Daegu, South Korea, Republic of Korea INTRODUCTION: Recently, in various kidney diseases including acute kidney injury (AKI), gender difference has begun to attract attention. Mitochondria are essential intracellular organelle for the maintenance of cellular homeostasis. It has been reported that mitochondrial contents differ between gender and short-term calorie restriction confers resistance to the cells against cellular stress. Cis-diamminedichloroplatinum II (cisplatin) is a widely used anticancer drug. However, its nephrotoxicity limits its use. Here we investigated gender difference in cisplatin nephrotoxicity, if it exists, and the involvement of energy metabolism in this gender difference. METHODS: Some mice were starved for 48 hrs before cisplatin (10mg/kg BW) administration. Kidney injury was evaluated by blood urea nitrogen concentration and morphology. RESULTS: Cisplatin significantly increased blood urea nitrogen (BUN) concentration in both male and female mice and this increase was greater in the male mice than female mice. In consistency with BUN increase, kidney tubular damage occurred after cisplatin and this damage was greater in the male mice. Starvation before cisplatin injection significantly reduced kidney functional and morphological damage in both male and female mice. After cisplatin injection, severe oxidative stress was observed in the mitochondria of kidney tubule epithelial cells. This oxidative stress was significantly more severe in male mice compared with that in female mice and was reduced by starvation. Cisplatin treatment reduced the expression of PGC-1a, a key regulator of mitochondrial biogenesis, in the kidney. Before cisplatin injection, PGC- 1a level was greater in the kidney of female then that in male, and starvation increased PGC-1a level in both. Cisplatin-induced decreases of PGC-1a level and renal function were significant less in the female mice than in the male mice. Furthermore, Starvation reduced cisplatin-induced mitochondrial oxidative stress, and increased superoxide dismutase 2 (SOD2) and isocitrate dehydrogenase 2 (IDH2), a NADP-dependent antioxidant enzyme of mitochondria. In addition, female kidney presented higher SOD2 and IDH2 levels. CONCLUSIONS: These results indicate that there are gender differences on cisplatin nephrotoxicity and this gender difference is associated with mitochondrial antioxidative enzymes. FP271 A NEW ANIMAL MODEL TO STUDY ACUTE KIDNEY INJURY- TO-CHRONIC KIDNEY DISEASE TRANSITION Giampiero Andrea-Massaro 1 , Florence Costalas 1 , Laura Ramudo 1 , Cristina Cuesta-Apausa 1 , Ana I Morales-Martin 1 , Isabel Fuentes-Calvo 1 , Sandra M. Sancho-Martinez 1 , Francisco J. Lopez-Hernandez 1 , Carlos Martinez-Salgado 1 1 Institute of Biomedical Research of Salamanca, Salamanca, Spain INTRODUCTION: Acute kidney injury (AKI) represents a clinical problem due to its increasing prevalence and associations with further morbidities. Patients who suffer from AKI have a higher risk of developing chronic renal damage (CKD) in relation to the severity and frequency of their episodes. After AKI, incomplete or maladaptive repair can result in the development and progression into CKD. Although the complete process of AKI to CKD transition remains unclear, one mechanism promoting this transition is fibrosis, where functional tissue is replaced by connective tissue. Advanced fibrosis will result in the loss of both organ architecture and functionality. Hypothesising that three AKI-inducing renal insults, at discrete time intervals, would be able to promote CKD transition, we designed and characterized a new animal model. Over the course of the study, we examined the presence of histological damage (interstitial fibrosis) and monitored renal function. METHODS: Male Wistar rats were subjected to three AKI inducing-renal interventions. Animals were treated intraperitoneally with 5 mg/kg of cisplatin (CDDP5), while control groups received saline solution. When renal function had recovered (D8), a 60-minute unilateral ischemia-reperfusion (I/R60) was performed on the left kidney. Sham rats were subjected to a simulated surgery. Two weeks later, rats were administered with 3 mg/kg of cisplatin (CDDP3) intraperitoneally, while controls received saline. Blood and urine were collected at: D0 (basal); D4 (AKI development); D8 (normalized renal function after AKI); D9 (1 day after ischemia); D15 and every week thereafter. Renal function was analysed by plasma creatinine, glomerular filtration rate, blood urea and proteinuria using colorimetric methods. At D56 all animals were sacrificed, and kidney samples were stained with Masson  s trichrome (MT) and Sirius Red (SR) to analyse the degree of fibrosis. RESULTS: Our data show that after three renal insults, MT and SR staining revealed a progressive fibrosis increase in both kidneys in the triple injury group (CDDP5 - I/R60 - CDDP3), but not in the double or single injury groups. There are no differences in renal function after the last AKI in the triple injury group (CDDP5 - I/R60 - CDDP3) with respect to controls or the double or single injury groups. CONCLUSIONS: The presence of fibrosis in both kidneys in our triple injury experimental group demonstrates that a maladaptive and incomplete repair mechanism occurred following AKI, although renal function seems to remain normal. Our results show the potential of this in vivo experimental model to reproduce AKI-to- CKD transition. FP272 MASSIVE INTRAVASCULAR HEMOLYMASSIVE INTRAVASCULAR HEMOLYSIS INDUCES ACUTE KIDNEY INJURY IN A NRF2-DEPENDENT WAY Cristina V azquez-Carballo 1 , Melania Guerrero-Hue 1 , Cristina Garc  ıa-Caballero 1 , Alfonso Rubio-Navarro 1 , Carmen Herencia 1 , Eduardo Gutie ´ rrez 2 , Claudia Yuste 2 , Angel Sevillano 2 , Manuel Praga 2 , Javier Egea 3 , Pablo Cannata-Ortiz 4 , Isabel Cortegano 5 , Bele ´ n De Andre ´s 5 , Maria Luisa Gaspar 5 , Susana Cadenas 6 , Patricia Michalska 7 , Rafael Le on 7 , Alberto Ortiz 1 , Jes us Egido 1 , Juan Antonio Moreno 1 1 Instituto de Investigaci on Sanitaria - Fundaci on Jime ´nez D  ıaz, Madrid, Spain, 2 Hospital 12 de Octubre, Madrid, Spain, 3 IIS-Hospital Universitario de la Princesa, Madrid, Spain, 4 IIS-Fundacion Jimenez Diaz Universidad Autonoma de Madrid, Madrid, Spain, 5 Centro Nacional de Microbiologia Instituto de Salud Carlos III, Madrid, Spain, 6 Centro de Biolog  ıa Molecular "Severo Ochoa" (CSIC-UAM), Madrid, Spain and 7 Instituto Te ofilo Hernando, Madrid, Spain INTRODUCTION: Nuclear factor erythroid-2-related factor 2 (Nrf2) plays a central role in the defense against oxidative stress by activating the expression of several antioxidant proteins and phase 2 detoxifying enzymes. Massive intravascular hemolysis is a common -condition in several pathologies and it is associated with acute kidney injury (AKI). In this context, free haemoglobin (Hb) can exert harmful effect by accumulating in the kidney, where it becomes cytotoxic. We investigated the role of Nrf2 in intravascular hemolysis and whether activation of this transcription factor may protect from Hb-mediated AKI. METHODS: We performed an experimental model of intravascular hemolysis- associated AKI by intraperitoneal injection of phenylhydrazine and analyzed renal function, oxidative stress and cell death in wild type (C57BL/6) and Nrf2 knockout mice 24 hour after the hemolysis induction. We also evaluated the protective effect of sulforaphane, a Nrf2 inducer, in vivo and in cultured murine tubular epithelial cells. RESULTS: In our experimental model, Hb-released as a result of intravascular hemolysis promoted AKI, resulting in increased creatinine and BUN serum concentration, enhanced expression of tubular injury markers (Kim-1 and NGAL), cell death (TUNEL) and oxidative stress. These pathological effects were increased in Nrf2-deficient mice, which showed decreased expression of Nrf2-related antioxidant enzymes, including HO-1 and ferritin. Nrf2 activation with sulforaphane protected against Hb-toxicity in mice and cultured tubular epithelial cells, ameliorating renal function, kidney injury and reducing oxidative stress and cell death. These Nrf2-mediated effects were independent of hemolysis since Hb levels in plasma, urine and kidney were similar in wyld type or Nrf2 knockout mice or after sulforaphane treatment. CONCLUSIONS: Our study identifies Nrf2 as a key molecule in the protection against renal damage associated to hemolysis. Moreover, Nrf2 activation may be a potential therapeutic target to prevent loss of renal function in patients with severe intravascular hemolytic crisis. These findings provide new insights into novel aspects of Hb-toxicity and may have important pathogenic and therapeutic implications for intravascular hemolysis related diseases. FP273 AKT1 IS INVOLVED IN RENAL DAMAGE AND APOPTOSIS AFTER RENAL ISCHEMIA REPERFUSION INJURY IN MICE MODEL Il Young Kim 1 , June Hyun Kim 1 , Min Jeong Kim 1 , Dong Won Lee 1 , Soo Bong Lee 1 , Cheol Gu Hwang 2 , Miyeun Han 2 , Harin Rhee 2 , Sang Heon Song 2 , Eun Young Seong 2 , Ihm Soo Kwak 2 1 Pusan National University Yangsan Hospital, Yangsan, Republic of Korea and 2 Pusan National University Hospital, Busan, Republic of Korea INTRODUCTION: Renal ischemia-reperfusion injury (IRI) is one of the major causes of acute kidney injury. The Akt has been reported to be involved in renal IRI. However, which one of Akt isoforms plays important role in renal IRI were not fully understood. In this study, we investigated the role of Akt1 in renal IRI. METHODS: Fifteen male C57BL/6J mice were allocated to three groups (n = 5 per group): the sham group, the IRI group, and Akt1 knockout (KO) IRI group. Renal IRI was induced by clamping the left renal artery for 30 min followed by reperfusion. At the 48 h of reperfusion, the renal damage was assessed by histologic grading. Apoptosis was assessed by the TUNEL method and morphological criteria. Expression of cleaved caspase-3, -9, and bcl-2 was also evaluated. RESULTS: The IRI caused an increase in kidney volume. The Akt1 KO alleviated this change. Semi-quantitative assessment of the histological lesions showed that the IRI group developed marked structural damage (tubular necrosis, hemorrhage, cast formation, and inflammation) whereas significantly less damage was observed in the Akt1 KO IRI group. The IRI group showed an increase in TUNEL-positive cells that was accompanied by morphological evidence of apoptosis. In the Akt1 KO IRI group, only a i138 | Abstracts Abstracts Nephrology Dialysis Transplantation Downloaded from https://academic.oup.com/ndt/article/34/Supplement_1/gfz106.FP271/5516334 by guest on 22 February 2023