Microarray-based analysis of ventilator-induced lung injury

Acute respiratory distress syndrome (ARDS) and acute lung injury (ALI) are a frequent cause of intensive care unit admission, affecting over 200,000 patients in the United States each year. Mechanical ventilation is a life-saving intervention in the setting of ARDS and ALI, but clinical trials have demonstrated that mechanical ventilation with excessive tidal volumes plays a role in promoting and perpetuating lung injury and leads to excess mortality. This process has been labeled ventilator-induced lung injury (VILI), but the molecular mechanisms driving this process and its interactions with predisposing risk factors such as sepsis and chemical injury remain incompletely understood. Genome-wide measurements of gene expression using microarray technology represent a powerful tool to examine the pathophysiology of VILI. Several recent studies have used this approach to study VILI in isolation and associated with endotoxin instillation or saline lavage. These studies and others examining gene expression profiles in epithelial cells subjected to cyclic stretch have provided novel insights on the molecular mechanisms underlying VILI. This review will summarize these findings and discuss implications for future studies.