Investigating the Role of CFTR in Human and Mouse Myometrium

Background: Abnormal cystic fibrosis transmembrane conductance regulator (CFTR) function in cystic fibrosis (CF) has been linked to airway smooth muscle abnormalities including bronchial hyperresponsiveness. However, a role for CFTR in other types of smooth muscle, including myometrium, remains largely unexplored. As CF life expectancy and the number of pregnancies increases, there is a need for an understanding of the potential role of CFTR in myometrial function. Methods: We investigated the role of CFTR in human and mouse myometrium. We used immunofluorescence to identify CFTR expression, and carried out contractility studies on spontaneously contracting term pregnant and non-pregnant mouse myometrium and term pregnant human myometrial biopsies from caesarean sections. Results: CFTR was found to be expressed in term pregnant mouse myometrium. Inhibition of CFTR, with the selective inhibitor CFTRinh-172, significantly reduced contractility in pregnant mouse and human myometrium in a concentration-dependent manner (44.89 +/- 11.02 term pregnant mouse, 9.23 +/- 4.75 term-pregnant human; maximal effect at 60 mu M expressed as a percentage of the pre-treatment control period). However, there was no effect of CFTRinh-172 in non-pregnant myometrium. Conclusion: These results demonstrate decreased myometrial function when CFTR is inhibited, which may have implications on pregnancy and labour outcome and therapeutic decisions for labour in CF patients.