Shock : molecular, cellular, and systemic pathobiological aspects and therapeutic approaches : the official journal the Shock Society, the European Shock Society, the Brazilian Shock Society, the International Federation of Shock Societies
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Exocytosis of neutrophil granules contributes to acute lung injury (ALI) induced by infection or inflammation, suggesting that inhibition of neutrophil exocytosis in vivo could be a viable therapeutic strategy. This study was conducted to determine the effect of a cell-permeable fusion protein that inhibits neutrophil exocytosis (TAT-SNAP-23) on ALI using an immune complex deposition model in rats. The effect of inhibition of neutrophil exocytosis by intravenous administration of TAT-SNAP-23 on ALI was assessed by albumin leakage, neutrophil infiltration, lung histology, and proteomic analysis of bronchoalveolar lavage fluid (BALF). ⋯ Proteomic analysis of BALF revealed that components of the complement and coagulation pathways were significantly reduced in BALF from TAT-SNAP-23-treated animals. Our results indicate that administration of a TAT-fusion protein that inhibits neutrophil exocytosis reduces in vivo ALI. Targeting neutrophil exocytosis is a potential therapeutic strategy to ameliorate ALI.
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Postconditioning prevents cardiomyocytes from ischemia/reperfusion-induced apoptosis. However, little is known about the molecular mechanisms that mediate the cardioprotective effect of postconditioning. ⋯ In addition, p53 is involved in the regulatory role of postconditioning in PUMA expression. Our data reveal a cardioprotective pathway of postconditioning in which it represses PUMA.
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The mechanisms contributing to hypoxia in lung contusion (LC) remain unclear and not temporally associated with the peak onset of acute inflammation. We investigated the role of oxidative stress in alteration of pulmonary arterial (PA) reactivity following LC. In addition, the role of antioxidants in reversing this process was examined. ⋯ SOD1 and 2 mRNA were upregulated, and soluble guanylyl cyclase mRNA was downregulated 24 h after LC. Immunohistochemistry and mass spectrometry revealed that levels of 3-nitrotyrosine were increased markedly at 4 h following LC consistent with superoxide generation and formation of peroxynitrite. Collectively, these data suggest that consumption of NO due to excess superoxide resulting in peroxynitrite formation leads to diminished vascular reactivity following LC.
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A recent study showed that the injection of mitochondria isolated from a nonischemic region mitigated myocardial injury. We tested the protective effects of infusing isolated mitochondria on the reperfusion injury in the liver of rats. A partial liver ischemia-reperfusion (I/R) model in male Wistar rats was used. ⋯ Our results show that the elevation of serum alanine aminotransferase (414.3 ± 67.1 vs. 208.8 ± 30.2 U/L), the necrosis of hepatocytes on hematoxylin-eosin staining, increase in positive counts in TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) staining (59.5% ± 4.4% vs. 24.6% ± 9.1%), the expression of cytosolic cytochrome c, cleaved caspase 9, and 4-hydroxynonenal were all reduced in the I/R-mito group, compared with the I/R-vehicle group. The membrane potential of the isolated mitochondria measured by JC-1 fluorescence remained high, and the infused mitochondria were distributed in the liver parenchyma at 240 min after reperfusion. These results demonstrate that an intrasplenic infusion of viable mitochondria isolated from the donor before reperfusion significantly reduced I/R injury in the liver.
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The aim of the present study was to examine the effect and possible mechanism of salvianolic acid B (SalB) on pulmonary microcirculation disturbance induced by lipopolysaccharide (LPS) in rat. Male Sprague-Dawley rats were subjected to thoracotomy under continuous anesthesia and mechanical ventilation. Albumin leakage from pulmonary capillary and the numbers of leukocytes adherent to the pulmonary capillary wall were determined for 60 min by an upright microscope upon LPS (2 mg · kg(-1) · h(-1)) infusion with or without administration of SalB (5 mg · kg(-1) · h(-1)). ⋯ In addition, LPS increased pulmonary tissue wet-to-dry weight ratio and tumor necrosis factor α and interleukin 8 levels in plasma and bronchoalveolar lavage fluid enhanced the expression of E-selectin, intercellular adhesion molecule 1, myeloperoxidase, MMP-2, and MMP-9, whereas it decreased the expression of AQP-1 and AQP-5 in pulmonary tissue, all of which were attenuated by SalB pretreatment. Salvianolic acid B pretreatment improves pulmonary microcirculation disturbance and lung injury on LPS exposure. More studies are required to evaluate the potential of SalB as an option for protecting lung from endotoxemia.