Extracellular superoxide dismutase haplotypes and acute lung injury: reading into the genome to understand mortality?

Intersectin-1s: an important regulator of cellular and molecular pathways in lung injury

Abstract Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are severe syndromes resulting from the diffuse damage of the pulmonary parenchyma. ALI and ARDS are induced by a plethora of local or systemic insults, leading to the activation of multiple pathways responsible for injury, resolution, and repair or scarring of the lungs. Despite the large efforts aimed at exploring the roles of different pathways in humans and animal models and the great strides made in understanding the pathogenesis of ALI/ARDS, the only viable treatment options are still dependent on ventilator and cardiovascular support. Investigation of the pathophysiological mechanisms responsible for initiation and resolution or advancement toward lung scarring in ALI/ARDS animal models led to a better understanding of the disease's complexity and helped in elucidating the links between ALI and systemic multiorgan failure. Although animal models of ALI/ARDS have pointed out a variety of new ideas for study, there are still limited data regarding the initiating factors, the critical steps in the progression of the disease, and the central mechanisms dictating its resolution or progression to lung scarring. Recent studies link deficiency of intersectin-1s (ITSN-1s), a prosurvival protein of lung endothelial cells, to endothelial barrier dysfunction and pulmonary edema as well as to the repair/recovery from ALI. This review discusses the effects of ITSN-1s deficiency on pulmonary endothelium and its significance in the pathology of ALI/ARDS.

Integrating microRNAs into a system biology approach to acute lung injury

Acute lung injury (ALI), including the ventilator-induced lung injury (VILI) and the more severe acute respiratory distress syndrome (ARDS), are common and complex inflammatory lung diseases potentially affected by various genetic and nongenetic factors. Using the candidate gene approach, genetic variants associated with immune response and inflammatory pathways have been identified and implicated in ALI. Because gene expression is an intermediate phenotype that resides between the DNA sequence variation and the higher level cellular or whole-body phenotypes, the illustration of gene expression regulatory networks potentially could enhance understanding of disease susceptibility and the development of inflammatory lung syndromes. MicroRNAs (miRNAs) have emerged as a novel class of gene regulators that play critical roles in complex diseases including ALI. Comparisons of global miRNA profiles in animal models of ALI and VILI identified several miRNAs (eg, miR-146a and miR-155) previously implicated in immune response and inflammatory pathways. Therefore, via regulation of target genes in these biological processes and pathways, miRNAs potentially contribute to the development of ALI. Although this line of inquiry exists at a nascent stage, miRNAs have the potential to be critical components of a comprehensive model for inflammatory lung disease built by a systems biology approach that integrates genetic, genomic, proteomic, epigenetic as well as environmental stimuli information. Given their particularly recognized role in regulation of immune and inflammatory responses, miRNAs also serve as novel therapeutic targets and biomarkers for ALI/ARDS or VILI, thus facilitating the realization of personalized medicine for individuals with acute inflammatory lung disease.