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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Notch signaling, a critical pathway in cell fate determination, is well known to be involved in immune and inflammatory reactions, whereas its role in acute lung injury (ALI) remains unclear. Here, we report that notch signal activity is upregulated in lung tissue harvested from an ALI mouse model (induced by zymosan). We showed that notch signal activity in lung tissue was increased 6 h after zymosan injection and peaked at 24 h. ⋯ In conclusion, the role of notch signaling is functionally significant in the development of ALI. Inhibition of notch signaling by pretreatment or posttreatment with DAPT likely exerts its effects in part by mediating the expression of proinflammatory and anti-inflammatory cytokines and influencing tissue neutrophil recruitment. These results also imply that notch inhibitors may help attenuate local inflammatory lung damage.
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Interleukin 1 receptor-like 1 (ST2) has been implicated as a negative regulator of Toll-like receptor signaling. We here sought to elucidate the role of ST2 in cytokine release and systemic infection caused by two common human sepsis pathogens, Streptococcus pneumoniae (gram-positive) and Klebsiella pneumoniae (gram-negative). ⋯ ST2 augments rather than inhibits cytokine release by blood leukocytes and splenocytes exposed to S. pneumoniae or K. pneumoniae, but plays a limited role in host defense during sepsis caused by these pathogens.
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Use of aspirin (acetylsalicylic acid [ASA]) was found to improve outcome in animal models of acute lung injury (ALI) or its more severe form, acute respiratory distress syndrome. In patients with acute respiratory distress syndrome, data indicating a protective effect of ASA are less convincing. We hypothesize that ASA in a high dose is superior to low-dose ASA in preventing lung injury. Also, the effect on lung injury of inhibiting platelet activation by clopidogrel was investigated. ⋯ High-dose ASA is superior to low-dose ASA, clopidogrel, and to a combination of clopidogrel and low-dose ASA in attenuating LPS-induced lung injury in mice, suggesting high-dose ASA to be the antiplatelet therapy of choice in further research on preventing ALI.
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Acute respiratory distress syndrome (ARDS) is a serious complication of sepsis and sepsis-associated ARDS is associated with significant morbidity and mortality. To date, no study has directly examined the epidemiology of ARDS in severe sepsis from the earliest presentation to the health care system, the Emergency Department (ED). ⋯ In patients presenting to the ED with severe sepsis, the rate of sepsis-associated ARDS development varied across the continuum of care. ARDS developed rapidly and was associated with significant mortality. Elevated serum lactate levels in the ED and a recently validated clinical prediction score were independently associated with the development of ARDS in severe sepsis.
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Sepsis is an acute inflammatory condition that can result in multiple organ failure and acute lung injury (ALI). Growth arrest-specific protein 6 (Gas6) is a broad regulator of the innate immune response involved with the NF-κB signaling pathway. We hypothesized that Gas6 could have a protective role in attenuating the severity of ALI and sepsis. ⋯ Moreover, rmGas6 reduced the in-vitro migration of differentiated human promyelocytic HL60 cells by 64%. Finally, the 10-day survival rate of mice subjected to CLP was increased from 31% in the vehicle group to 67% in the rmGas6 group (P<0.05). Thus, Gas6 has potential to be developed as a novel therapeutic agent to treat patients with sepsis and acute lung injury.