Description of Research Expertise

Research interests
-Membrane protein and phospholipid trafficking in lung epithelial cells
-Control of lung lipoprotein synthesis and secretion
-Lipid and protein oxidation in ischemia-reperfusion injury.

Research interests

Oxidant stress and antioxidant defense, oxidant mediated cell signaling, peroxiredoxins as antioxidant enzymes, endothelial cell mechanotransduction, ischemia-reperfusion injury, membrane protein and phospholipid trafficking in lung epithelial cells, lung surfactant phospholipid turnover.

Key words

Oxidants, antioxidant enzymes, cell signaling, endothelial cells, mechanotransduction, antioxidant enzymes, ischemia-reperfusion, lung surfactant, phospholipids.

Research description

Oxidant stress is being increasingly recognized as a mechanism for tissue injury. The range of pathologies includes diseases associated with ischemia/reperfusion, tissue inflammation, and exposure to redox active toxins including environmental pollutants. My laboratory utilizes the breathing of oxygen at high concentrations and exposure to the herbicide paraquat as models of oxidant stress. The special focus is on lung injury and especially on biochemical manifestations of lipid and protein oxidation. Additional emphasis is placed upon the role of antioxidant enzymes with a special focus on the recently described novel peroxidases that constitute the peroxiredoxin family. Reactive oxygen species are involved not only in tissue pathology but are now recognized as important signaling molecules. Our laboratory studies the role of ROS in signaling during the early phases of tissue ischemia. The basis for the signaling effect is altered mechanotransduction of the endothelial cells related to loss of shear stress with ischemia. These events result in a signaling cascade leading to release of NO and tissue angiogenesis.

A second area of research relates to lung surfactant, a phospholipid protein complex that is secreted by the lung alveolar epithelium and serves to promote lung stability by reducing the surface tension at the air-liquid interface in the alveolar space. The surfactant components following secretion are endocytosed and reprocessed intracellularly, thus constituting a secretion-recycling pathway. Current interest in our laboratory is in the role of peroxiredoxin 6 as a novel phospholipase A2 enzyme that is involved in the degradation of internalized surfactant phospholipids and in the provision of substrate for phospholipid resynthesis.