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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Kidney ischemia-reperfusion injury (IRI) activates cellular and soluble mediators that drive lung inflammatory cascades, tumor necrosis factor receptor 1 (TNFR1)-mediated programmed cell death, and microvascular barrier dysfunction, leading to acute lung injury. We hypothesized that lung microvascular endothelial cells (ECs), with their integral role in maintaining the lung-semipermeable barrier, were key cellular targets of TNFR1-mediated apoptosis during ischemic AKI. Male C57/BL6 mice and Sprague-Dawley rats underwent 60 min of bilateral renal pedicle occlusion (IRI) or sham laparotomy (sham) and were killed at 4 or 24 h. ⋯ Compared with vehicle, treatment of rat lung microvascular ECs with etanercept inhibited proinflammatory gene activation (E-selectin, intercellular adhesion molecule 1, interleukin 6, RhoB) and apoptosis during ischemic AKI. Ischemic AKI drives distinct proinflammatory and proapoptotic changes in the pulmonary EC transcriptome with TNFR1-dependent caspase activation and programmed cell death. Further investigation of potential EC mechanisms of kidney-lung crosstalk during AKI may identify potential therapeutic targets for this deadly disease.
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Apocynin (Apo) suppresses the generation of reactive oxygen species that are implicated in lipopolysaccharide (LPS)-induced lung injury (LPSLI). We thus hypothesized that Apo may attenuate LPSLI. In addition, we explored the cellular and molecular mechanisms of Apo treatment in LPSLI. ⋯ In addition, Apo attenuated the increase in lung weight, bronchoalveolar lavage fluid albumin content, and the histopathologic lung injury score. In conclusion, LPSLI is associated with increased inflammatory responses, apoptosis, and coagulation. The administration of Apo attenuates LPSLI through downregulation of the inflammatory responses and apoptosis.
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Aberrant activation of neutrophils during sepsis results in the widespread release of proinflammatory mediators, leading to multiorgan system failure and death. However, aberrant activation of neutrophils during sepsis results in the widespread release of harmful inflammatory mediators causing host tissue injuries that can lead to multiorgan system failure and death. ⋯ Second, β1 integrin (CD29) was highly upregulated on the neutrophils isolated from both septic patients and animals. Finally, conditional genetic ablation of β1 integrin from granulocytes also improved survival and bacterial clearance in septic animals Thus, our results indicate that expression of β1 integrin is important for modulating neutrophil trafficking during sepsis and that therapeutics designed against β1 integrins may be beneficial.
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Shen-Fu injection (SFI) following cardiac arrest exhibits cardioprotective effects, but its effect on myocardial dysfunction, a critical issue following resuscitation, is unclear. This study sought to examine whether SFI reduces postresuscitation myocardial dysfunction in a porcine model of cardiac arrest by modulating apoptosis. After 8 min of untreated ventricular fibrillation and 2 min of basic life support, 24 pigs were randomized divided into three groups, which received central venous injection of either Shen-Fu (SFI group; 1.0 mL/kg), epinephrine (EP group; 0.02 mg/kg), or saline (SA group). ⋯ Caspase 3-mediated apoptosis occurs following myocardial injury after cardiopulmonary resuscitation in pigs. Shen-Fu injection decreased myocardial injury; improved myocardial ultrastructure; inhibited Bcl-2, Bax, and caspase 3 expression; and reduced myocardial apoptosis. Therefore, SFI could significantly attenuate postresuscitation myocardial dysfunction by modulating apoptosis.
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Human C1 inhibitor (C1INH) prevents endotoxin shock via a direct interaction with Gram-negative bacterial lipopolysaccharide (LPS) and improves survival in animal models of sepsis. In this report, we further characterize the interaction of C1INH with LPS and whole live bacteria. We investigate C1INH interactions with LPS from five different strains of Gram-negative enteric bacteria known to participate in the pathogenesis of human sepsis. ⋯ The binding of both native and reactive center-cleaved, inactive C1INH results in inhibition of LPS-induced proinflammatory cytokine production. Furthermore, we demonstrate the ability of C1INH to bind at the surface of only a restricted number of whole live Gram-negative bacteria as well as mutant bacteria expressing a truncated LPS lacking the O-antigen. These data reveal the interaction of C1INH with a wide range of enteric bacterial LPS and strongly suggest that the interaction between C1INH and the surface of Gram-negative microorganisms is determined by the length of the polysaccharide chain of the endotoxin molecule.