Apoptotic process in cystic fibrosis cells

Cystic fibrosis (CF) is a recessively inherited disease caused by genetic lesions in CF transmembrane conductance regulator (CFTR) gene. CF is characterized by exaggerated inflammation, progressive tissue damage, and chronic bacterial colonization, mainly in the respiratory tract. The mechanisms underlying these pathological changes are increasingly well understood. However, apoptotic dysfunction in CF disease is still debated since studies report controversial results. Nonetheless, it is clear that apoptosis participates to onset of pathology and concerns various types of cells with variable susceptibility. Apoptosis is a physiological process necessary for the preservation of homeostasis of epithelial organization and function for clearance of inflammatory cells. Increased susceptibility to apoptosis in epithelial cells and failed apoptosis in neutrophils would contribute to the self-perpetuating inflammatory cycle in CF. Also, retention of mutated CFTR in the endoplasmic reticulum participates to inflammation which may trigger apoptosis. Independently of the sensibility to apoptosis of CF cells, it has been shown that clearance of apoptotic cells, due in part to decrease in efferocytosis, is flawed and that accumulation of such cells may contribute to ongoing inflammation in CF patients. Despite great advance in understanding CF pathophysiology, there is still no cure for the disease. The most recent therapeutic strategies are directed to target CFTR protein using cell and gene therapy as well as pharmacotherapy.