Critical involvement of Th1-related cytokines in renal injuries induced by ischemia and reperfusion Vanessa Nunes de Paiva a , Rebecca M.M. Monteiro a,b , Vilmar de Paiva Marques c , Marcos Antonio Cenedeze a , Vicente de P.A. Teixeira c , Marlene A. dos Reis c , Alvaro Pacheco-Silva a,d , Niels O.S. Câmara a,b, ⁎ a Laboratory of Clinical and Experimental Immunology. Nephrology Division, Department of Medicine - Universidade Federal de São Paulo UNIFESP-EPM, São Paulo, Brazil b Laboratory of Transplantation Immunobiology, Department of Immunology, Universidade de São Paulo, São Paulo, Brazil c Department of Pathology, Universidade Federal do Triangulo Mineiro, Uberaba, Minas Gerais, Brazil d IEP, Hospital Israelita Albert Einstein, São Paulo, Brazil abstract article info Article history: Received 10 April 2008 Accepted 13 November 2008 Keywords: Acute renal failure Ischemia and reperfusion injury Cytokines IL-12 Interferon gamma IL-6 HO-1 Renal ischemia and reperfusion injury (IRI) is considered an inflammatory syndrome. To move forward in its pathogenesis, we exploited the role of several cytokines on renal damages triggered by IRI. Specifically to evaluate the role of Th1 immune profile in this system, IL-12, IFN-γ, and IFN-γ/IL-12 deficient (KO) mice on C57BL/6 background and their controls were subjected to IRI. In each group, blood and kidney samples were harvested. Renal function was evaluated by serum creatinine and renal morphometric analyses. Gene expression of IL-6 and HO-1 were also investigated by Q-PCR. IFN-γ KO animals presented the highest impairment in renal function compared to controls. Conversely, IL-12 KO animals were absolutely protected and, in a lesser extent, IFN-γ/IL-12 KO double knockout was also protected from IRI. Gene expression analyses showed higher expression of HO-1, a cytoprotective gene, and IL-6, a pro-inflammatory cytokine, in IFN-γ deficient animals subjected to IRI. Our results confirm that Th1 related cytokines such as IL-12 and IFN-γ are critically involved in renal ischemia and reperfusion injury. © 2008 Elsevier B.V. All rights reserved. 1. Introduction Acute renal failure (ARF) is an inflammatory consequence of a sudden and transient interruption of blood flow in the kidneys [1,2] and remains as a common issue in the clinical practice, lacking satisfactory therapeutic options. Despite diagnostic and treatment advances, the mortality and morbidity rates remain unchanged for the last decades [3]. Ischemia reperfusion injury (IRI) has an important role in its pathogenesis, in native organs and in transplanted grafts [4]. ARF pathogenesis is multifaceted, as the sudden interruption of blood flow to the kidneys unleashes inflammation and innate immune responses such as production of reactive oxygen species, complement and neutrophils activation, up-regulation of adhesion molecules and tubular cell death. Nevertheless it is known that more specific immune response plays a crucial role in this process [5]. In the last years, leucocytes have been shown to have a role in the pathogenesis of IRI, and at this time, many studies focused on neutrophils infiltration [6]. The role of lymphocytes emerged in IRI after the observation that treatment with anti-ICAM-1 elicits protec- tion in renal graft human receptors. It was observed that delayed graft function (DGF) rates were smaller than those from untreated patients receiving the contra-lateral organ [7]. In an experimental study, mice that received anti-ICAM-1 at the moment of renal ischemia presented a protection, with decreased functional damage of the organ [8], showing that both leukocytes and adhesion molecules play critical roles in ARF. From these studies to now, many groups have reported the participation of TCD4 + and TCD8 + lymphocytes in renal and other organs subjected to IRI [9–11]. One of these reports focused on nu/nu mice that had been adoptively transferred with an enriched CD4+ T cell population obtained from mice that were deficient in either CD28 or IFN-γ. They found that both CD28 and IFN-γ are important components of CD4 + T cell-mediated renal injury following IRI, as adoptively transferred mice had no increase in serum creatinine levels compared with nontransferred nu/nu mice [11]. Experiments with B cell deficient mice reported the involvement of these cells on the pathogenesis of IRI, since they presented an improvement of renal function and less tubular injury when sub- jected to IRI, compared to wild type [12]. However, it was observed that RAG-1 deficient mice, which lack B and T cells were not protected from IRI [13]. On the other hand, Yokota-Ikeda et al. tested the effect of depletion of T cells in an experimental IRI model using thymectomized mice or T cell-depleting monoclonal antibodies (GK1.5, 2.43, 30.H12). International Immunopharmacology 9 (2009) 668–672 Abbreviations: IRI, Ischemia and Reperfusion Injury; ARF, Acute Renal Failure; DGF, Delayed Graft Function; HO-1, Heme Oxygenase-1. ⁎ Corresponding author. Immunology Division, Department of Immunology, Institute of Biomedical Science, Universidade de São Paulo, São Paulo, Brazil. Av. Prof Lineu Prestes, 1730, 05508-900 São Paulo, SP, Brazil. Tel.: +55 11 30917388; fax: +55 11 3091 7224. E-mail address: niels@icb.usp.br (N.O.S. Câmara). 1567-5769/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.intimp.2008.11.012 Contents lists available at ScienceDirect International Immunopharmacology journal homepage: www.elsevier.com/locate/intimp