Therapeutic potential of phosphatidylinositol 3-kinase inhibitors in inflammatory respiratory disease.

The phosphoinositide 3-kinase(s) (PI3K) are a family of proteins that catalyze the phosphorylation of the 3-OH position of phosphoinositides and generate lipids that control a wide variety of intracellular signaling pathways. They are classified into three families according to their structure and substrate specificity and are thought to have distinct biological roles. Recent studies suggested that numerous components of the PI3K pathway play a crucial role in the expression and activation of inflammatory mediators, inflammatory cell recruitment, immune cell function, airway remodeling, and corticosteroid insensitivity in chronic inflammatory respiratory disease. Selective PI3K inhibitors have been developed that reduce inflammation and some characteristics of disease in experimental animal models. Targeting specific PI3K isoforms that may be overexpressed or overactive in disease should allow for selective treatment of respiratory diseases. Encouraging data from animal models, primary cells and clinical studies in other diseases suggest that inhibitors of PI3K/Akt may prove to be useful novel therapies in the treatment of asthma and chronic obstructive pulmonary disease.