RESUMO
Ischemic-reperfusion injury (IRI) triggers an inflammatory response involving neutrophils/macrophages, lymphocytes and endothelial cells. Galectin-3 is a multi-functional lectin with a broad range of action such as promotion of neutrophil adhesion, induction of oxidative stress, mastocyte migration and degranulation, and production of pro-inflammatory cytokines. The aim of this study was evaluate the role of galectin-3 in the inflammation triggered by IRI. Galectin-3 knockout (KO) and wild type (wt) mice were subjected to 45 min of renal pedicle occlusion. Blood and kidney samples were collected at 6, 24, 48 and 120 h. Blood urea was analyzed enzymatically, while MCP-1, IL-6 and IL-1beta were studied by real-time PCR. Reactive oxygen species (ROS) was investigated by flow cytometry. Morphometric analyses were performed at 6, 24, 48 and 120 h after reperfusion. Urea peaked at 24 h, being significantly lower in knockout animals (wt = 264.4 +/- 85.21 mg/dl vs. gal-3 KO = 123.74 +/- 29.64 mg/dl, P = 0.001). Galectin-3 knockout animals presented less acute tubular necrosis and a more prominent tubular regeneration when compared with controls concurrently with lower expression of MCP-1, IL-6, IL-1beta, less macrophage infiltration and lower ROS production at early time points. Galectin-3 seems to play a role in renal IRI involving the secretion of macrophage-related chemokine, pro-inflammatory cytokines and ROS production.
Assuntos
DNA/genética , Galectina 3/genética , Expressão Gênica , Transplante de Rim/patologia , Rim/irrigação sanguínea , Traumatismo por Reperfusão/metabolismo , Animais , Autoantígenos , Biomarcadores , Quimiocina CCL2/biossíntese , Quimiocina CCL2/genética , Modelos Animais de Doenças , Citometria de Fluxo , Seguimentos , Galectina 3/biossíntese , Imuno-Histoquímica , Interleucina-1beta/biossíntese , Interleucina-1beta/genética , Interleucina-6/biossíntese , Interleucina-6/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Reação em Cadeia da Polimerase , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/patologiaRESUMO
BACKGROUND/AIMS: Recent evidence shows a critical role of the CD4+ T cell with the Th1/Th2 paradigm as a possible effector mechanism in ischemia and reperfusion injury. We hypothesize that a polarized Th1 activation response may negatively influence the renal IRI through its relationship with chemokine production (MCP-1) and with a protective tissue response (HO-1). METHODS: We subjected mice to renal ischemia for 45 min using IL-4 and IL-12 knockout C57BL/6. We then measured serum urea levels, performed histomorphometric analysis for tubular necrosis and regeneration, and evaluated the mRNA expression of HO-1, t-bet, Gata-3 and MCP-1 by real-time PCR at 24, 48 and 120 h after surgery. RESULTS/CONCLUSIONS: The IL-4 knockout mice had a statistically significant rise in serum urea levels post IRI compared with control animals. The IL-12-deficient mice were not affected. The IL-4-deficient mice had a statistically significant increase in tubular injury and impairment in cell regeneration. The IRI in IL-4-deficient mice was accompanied by higher levels of HO-1, t-bet and later up-regulation of MCP-1. These findings suggest that the deleterious effects of the Th1 cell involve increased production of chemokines such as MCP-1.
