Characterising Signalling Pathways In Cystic Fibrosis

MCT Research Talks

Cystic Fibrosis (CF) is a progressive, genetic disease that causes persistent lung infections and limits the ability to breathe over time. CF is caused by mutations in the Cystic Fibrosis Transmembrane Regulator (CFTR) gene which encodes a chloride channel responsible for helping conduct chloride and other ions across epithelial membranes. Loss of functional CFTR channel disrupts ionic homeostasis resulting in mucus production that clogs the lungs and results in a vicious cycle of chronic infection/inflammation. There are almost 2,000 different variants in the CFTR gene and 70 % of CF patients contain a mutation at position 508, which results in the loss of Phe508 and disruption of the folding pathway of CFTR. ΔF508 CFTR is a trafficking mutant that is retained in the endoplasmic reticulum (ER) and unable to reach the plasma membrane and function correctly as a chloride channel. The Coppinger research lab is focused on understanding the basic mechanisms of CF disease with a focus on the ΔF508 mutation and translating these findings into diagnostics/therapies. We are particularly interested in two areas of research 1. Using basic science technologies to identify novel signalling pathways in CF to discover new CFTR corrector therapies in ΔF508 CF models. We have recently discovered the PI3K/Akt/mTOR signalling pathway to be dysregulated in CF models and a possible therapeutic avenue worth further exploration in CF. Additionally, we are interested in 2. Investigating how diminished ΔF508 CFTR activity leads to heightened inflammatory cell recruitment and CF airway pathogenesis. Exosomes are nanovesicles (40–100 nm) actively secreted by cells and are crucial mediators of intercellular communications. We hypothesised that exosomes may be released from ΔF508 CF patient bronchial cells/fluids and play a role in regulating immune cell function. Preliminary data has confirmed this hypothesis and also indicated exosomal signatures may possibly serve as markers of disease progression in CF. These studies are in collaboration between several groups at the National Children’s Research Centre, Royal College of Surgeons in Ireland, Beaumont Hospital University College Dublin, Cystic Fibrosis Unit, St Vincent’s Hospital.

Judith Coppinger and her team: Mark Ward and Zivile Useckaite