Legend: A549 cells expressing Rat GFP-Na,K-ATPase α-1 under steady-state conditions and then stimulated with Forskolin
Patients with acute lung injury have lung edema accumulation and impaired alveolar fluid reabsorption (AFR) which is associated with increased mortality. Alveolar fluid reabsorption is effected by vectorial Na+ transport via apical Na+ channels and basolateral Na,K-ATPase of the alveolar epithelium. We and others have reported that β-adrenergic agonists upregulate the Na,K-ATPase in alveolar epithelial cells by increasing the traffic and recruitment of Na,K-ATPase containing vesicles into the cell membrane, resulting in increased catalytic activity. Moreover, GPCR-mediated upregulation of the Na,K-ATPase resulted in increased alveolar fluid clearance in normal lungs and in rodent models of lung injury. We are investigating fundamental aspects of Na,K-ATPase regulation and active Na+ transport in lungs which will help with the design of new strategies to increase lung edema clearance.