OBJECTIVE: To examine the temporal relationship of pulmonary TNF-alpha production to acute lung injury (ALI) during hemorrhagic shock (HS). METHODS: HS was induced in mice by removal of 30% of calculated total blood volume. Lung TNF-alpha was measured by ELISA. Lung neutrophil accumulation was detected by immunofluorescent staining, and pulmonary microvascular permeability was assessed using Evans blue dye. RESULTS: While HS induced a slight and transient increase in lung TNF-alpha, neutrophil accumulation preceded the change in lung TNF-alpha. However, lung neutrophil accumulation and the increase in microvascular permeability were abrogated in TNF-alpha knockout mice, and both were restored by administration of low dose TNF-alpha to TNF-alpha knockout mice prior to HS. Both neutrophil accumulation and microvascular leak were abrogated in p55 TNF-alpha receptor knockout mice, while p75 TNF-alpha receptor knockout mice behaved similar to wild type. CONCLUSION: A low level of pulmonary TNF-alpha is sufficient to mediate HS-induced acute lung injury and that the p55 TNF-alpha receptor plays a dominant role in regulating the pulmonary inflammatory response to HS. The results suggest that anti-TNF-alpha strategies for the control of the pulmonary inflammatory response to HS can be directed toward antagonizing the p55 TNF-alpha receptor.
OBJECTIVE: To examine the temporal relationship of pulmonary TNF-alpha production to acute lung injury (ALI) during hemorrhagic shock (HS). METHODS: HS was induced in mice by removal of 30% of calculated total blood volume. Lung TNF-alpha was measured by ELISA. Lung neutrophil accumulation was detected by immunofluorescent staining, and pulmonary microvascular permeability was assessed using Evans blue dye. RESULTS: While HS induced a slight and transient increase in lung TNF-alpha, neutrophil accumulation preceded the change in lung TNF-alpha. However, lung neutrophil accumulation and the increase in microvascular permeability were abrogated in TNF-alpha knockout mice, and both were restored by administration of low dose TNF-alpha to TNF-alpha knockout mice prior to HS. Both neutrophil accumulation and microvascular leak were abrogated in p55TNF-alpha receptor knockout mice, while p75TNF-alpha receptor knockout mice behaved similar to wild type. CONCLUSION: A low level of pulmonary TNF-alpha is sufficient to mediate HS-induced acute lung injury and that the p55TNF-alpha receptor plays a dominant role in regulating the pulmonary inflammatory response to HS. The results suggest that anti-TNF-alpha strategies for the control of the pulmonary inflammatory response to HS can be directed toward antagonizing the p55TNF-alpha receptor.
Authors: Anirban Banerjee; Ernest E Moore; Nathan J McLaughlin; Luis Lee; Wilbert L Jones; Jeffrey L Johnson; Trevor L Nydam; Christopher C Silliman Journal: Shock Date: 2013-04 Impact factor: 3.454