title: Contrasting roles for STAT4 and STAT6 signal transduction pathways in murine renal ischemia-reperfusion injury.
abstract: Recent data support a modulatory role for CD4 T cells in experimental renal ischemia-reperfusion injury (IRI). CD4 T cells can functionally differentiate to either a Th1 (IFN-gamma producing) or the counterbalancing Th2 (IL-4) phenotype. The enzymes signal transducers and activators of transcription (STAT) 4 and STAT6 regulate Th1 or Th2 differentiation and cytokine production, respectively. We therefore hypothesized that mice that were STAT4 deficient would be protected from renal IRI and that STAT6-deficient mice would have a more severe course. Intracellular cytokine staining of splenocytes from STAT4-/- or STAT6-/- exhibited distinct IFN-gamma and IL-4 cytokine expression profiles. STAT6-/- had markedly worse renal function and tubular injury postischemia compared with wild type. STAT4-/- had only mildly improved function. Renal phagocyte infiltration and ICAM-1 upregulation were similar in STAT4-/-, STAT6-/-, and wild type. To evaluate if the mechanism of the marked worsening in the STAT6-/- mice could be due to IL-4 deficiency, IL-4-deficient mice were studied and had similar postischemic phenotype to STAT6-/- mice. These data demonstrate that the STAT6 pathway has a major protective role in renal IRI. IL-4 deficiency is a likely mechanism underlying the STAT6 effect. A "yin-yang" role for inflammation is emerging in renal IRI, similar to recent observations in atherosclerosis.
authors.affiliation: Division of Nephrology, Johns Hopkins Univ. School of Medicine, Rm. 970, 720 Rutland Ave., Baltimore, MD 21205, USA.
authors.forename: Naoko
authors.initials: N
authors.lastname: Yokota
authors.forename: Melissa
authors.initials: M
authors.lastname: Burne-Taney
authors.forename: Lorraine
authors.initials: L
authors.lastname: Racusen
authors.forename: Hamid
authors.initials: H
authors.lastname: Rabb
mesh_terms: D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D015870:Gene Expression / Q000276:immunology; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics; D007371:Interferon-gamma / Q000235:genetics; D007375:Interleukin-1 / Q000235:genetics; D015847:Interleukin-4 / Q000235:genetics / Q000378:metabolism; D015850:Interleukin-6 / Q000235:genetics; D007668:Kidney / Q000276:immunology / Q000378:metabolism*; D007958:Leukocyte Count; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D009504:Neutrophils / Q000166:cytology / Q000201:enzymology; D009195:Peroxidase / Q000378:metabolism; D010641:Phenotype; D015427:Reperfusion Injury / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology*; D050797:STAT4 Transcription Factor; D050800:STAT6 Transcription Factor; D015398:Signal Transduction / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; D007375:Interleukin-1; D015850:Interleukin-6; D050797:STAT4 Transcription Factor; D050800:STAT6 Transcription Factor; C494091:Stat4 protein, mouse; C494100:Stat6 protein, mouse; D015534:Trans-Activators; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; D015847:Interleukin-4; D007371:Interferon-gamma; D009195:Peroxidase