ARDS and knowledge translation

XB130 deficiency enhances lipopolysaccharide-induced septic response and acute lung injury

XB130 is a novel oncoprotein that promotes cancer cell survival, proliferation and migration. Its physiological function in vivo is largely unknown. The objective of this study was to determine the role of XB130 in lipopolysaccharide (LPS)-induced septic responses and acute lung injury. LPS was intraperitoneally administrated to Xb130 knockout (KO) and wild type (WT) mice. There was a significant weight loss in KO mice at Day 2 and significantly higher disease scores during the 7 days of observation. The levels of tumor necrosis factor-alpha, monocyte chemoattractant protein-1, interleukin-6 and interleukin-10 in the serum were significantly higher in KO mice at Day 2. In KO mice there were a significantly higher lung injury score, higher wet/dry lung weight ratio, more apoptotic cells and less proliferative cells in the lung. Macrophage infiltration was significantly elevated in the lung of KO mice. There was significantly increased number of p-GSK-3β positive cells in KO mice, which were mainly neutrophils and macrophages. XB130 is expressed in alveolar type I and type II cells in the lung. The expression in these cells was significantly reduced after LPS challenge. XB130 deficiency delayed the recovery from systemic septic responses, and the presence of XB130 in the alveolar epithelial cells may provide protective mechanisms by reducing cell death and promoting cell proliferation, and reducing pulmonary permeability.

PTX3 as a potential biomarker of acute lung injury: supporting evidence from animal experimentation

OBJECTIVE

Increased expression of long pentraxin 3 (PTX3) has been found in patients with sepsis or acute respiratory distress syndrome. Tissue factor (TF) activation plays an important role in the pathogenesis of acute lung injury. The present study sought to determine the relationship between PTX3 expression and TF activation in acute lung injury.

METHODS

Lung injury was induced by intratracheal instillation of lipopolysaccharide (LPS) in mice, and the PTX3 expression, TF activation and lung injury were determined. We also treated the lung injury with an anti-human tissue factor monoclonal antibody in human tissue factor knock-in (hTF-KI) mice.

RESULTS

Balb/c mice were challenged with increasing doses of LPS. After 24 h, PTX3 protein in the bronchioalveolar lavage fluid was increased in parallel with the severity of lung injury, and correlated with tissue factor (TF) activity. The expression and distribution of PTX3 and TF were further documented in detail 6 h after LPS (5 mg/kg) instillation. Treatment with anti-human TF monoclonal antibody dramatically attenuated LPS-induced lung injury, alveolar fibrin deposition and inflammatory cell infiltration in"humanized" hTF-KI mice 6 h after LPS challenge. The PTX3 expression was significantly decreased by the anti-coagulant therapy.

CONCLUSION

These results support the clinical finding that PTX3 may be a useful biomarker to the reflect severity of lung injury and provide effective therapies. The interplay between PTX3 and TF could be a potential mechanism that mediates lung injury.