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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Streptococcal toxic shock syndrome is most frequently associated with Streptococcus pyogenes of the M1 serotype. Simvastatin protects against M1 protein-induced acute lung damage, although downstream mechanisms remain elusive. Herein, we hypothesized that geranylgeranylation might regulate proinflammatory effects in M1 protein-induced lung injury. ⋯ Notably, GGTI-2133 abolished M1 protein-induced gene expression of CXC chemokines in alveolar macrophages. These novel findings indicate that geranylgeranyl transferase is an important regulator of neutrophil recruitment and CXC chemokine production in the lung. Thus, targeting geranylgeranyl transferase might be a potent way to ameliorate streptococcal M1 protein-triggered acute lung injury.
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Sepsis is primarily a disease of the aged, with 65% of sepsis cases reported in patients older than 65 years and 80% of deaths due to sepsis occurring in this age group. Klotho knockout mice (Klotho mice) are a mouse model of accelerated aging and shortened life span. The purpose of the study was to elucidate the immunological changes occurring in Klotho mice during sepsis. ⋯ Both flow cytometric and immunohistological analyses showed a dramatic increase in caspase 3-positive cells in the thymus and spleen of Klotho-CLP mice (P < 0.01). Serum concentrations of interleukin 6, tumor necrosis factor α, and interleukin 10 were higher in Klotho-CLP mice than in WT-CLP mice. Hypercytokinemia with impaired bacterial clearance and increased apoptosis of lymphocytes may be related to poor survival in Klotho-septic mice.
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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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Chronic lung diseases cause serious morbidity and mortality, and effective treatments are limited. Induced pluripotent stem cells (iPSCs) lacking the reprogramming factor c-Myc (3-gene iPSCs) can be used as ideal tools for cell-based therapy because of their low level of tumorigenicity. In this study, we investigated whether 3-gene iPSC transplantation could rescue bleomycin-induced pulmonary fibrosis. ⋯ Furthermore, IP-10 neutralization via treatment with IP-10-neutralizing antibodies ameliorated the reparative effect of either 3-gene iPSCs or iPSC-CM on collagen content, neutrophil and monocyte accumulation, pulmonary fibrosis, and recipient survival. Intravenous delivery of 3-gene iPSCs/iPSC-CM alleviated the severity of histopathologic and physiologic impairment in bleomycin-induced lung fibrosis. The protective mechanism was partially mediated by the early moderation of inflammation, reduced levels of cytokines and chemokines that mediate inflammation and fibrosis, and an increased production of antifibrotic IP-10 in the injured lungs.