Abstract 551: Loss of ABCG1 Specifically in Pulmonary Type 2 Cells Results in Impaired Surfactant Lipid Metabolism

Cardiovascular disease (CVD) is the leading cause of death in the United States, and patients with pulmonary disease are at least 2-fold more likely to develop cardiovascular complications. Whole-body cholesterol balance is a complex and tightly regulated process. The sterol-transporter ATP Binding Cassette transporter G1 (ABCG1) is critical for maintaining normal cellular cholesterol and lipid homeostasis. After the liver and intestine, the lung is the 3rd most active lipid-secreting organ. Pulmonary alveolar proteinosis (PAP) is a rare lung disease characterized by the accumulation of surfactant lipids and proteins in the pulmonary alveoli resulting in respiratory distress. For almost all reported cases the underlying cause is unknown. Synthesis and secretion of surfactant in the lung is restricted to epithelial type 2 pneumocytes (T2 cells). However, subsequent clearance of surfactant from the hypophase is dependent upon both T2 cells and macrophages. Both T2 cells and macrophages express high levels o...