Functional evaluation of the cystic fibrosis transmembrane conductance regulator in the endocervix

Abstract

The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is an apical membrane chloride/bicarbonate ion channel in epithelial cells. Mutations in CFTR cause cystic fibrosis (CF), a disease characterized by thickened mucus secretions and is associated with subfertility and infertility. CFTR function has been well characterized in vitro and in vivo in airway and other epithelia studies. However, little is known about CFTR function in the cervix in health and its contribution to cyclic regulation of fertility from endocervical mucus changes. Contributing to this research gap is the lack of information on effect of sex steroid hormones on CFTR expression in cervix epithelial cells across the menstrual cycle. Herein we demonstrate hormonal regulation of CFTR expression in endocervical cells both in vitro and in vivo, and that conditionally reprogrammed endocervical epithelial cells can be used to interrogate CFTR ion channel function. CFTR activity was demonstrated in vitro using electrophysiology methods and functionally inhibited with the CFTR-specific inhibitors inh-172 and GlyH-101. We also report that CFTR expression is increased by estradiol in the macaque cervix both in vitro and in vivo in Rhesus macaques treated with artificial menstrual cycles. Estrogen upregulation of CFTR is blocked in vivo by co-treatment with progesterone. Our findings provide the most comprehensive evidence to date that steroid hormones drive changes in CFTR expression. These data are integral to understanding the role of CFTR as a fertility regulator in the endocervix. Summary: CFTR is hormonally regulated and functional in the macaque endocervix.

Transcriptional profiling of mucus production and modification in rhesus macaque endocervical cells under hormonal regulation

“…However, our sample size was limited by resources and ethical considerations, and with endocervical cells harvested from four NHPs, our small sample size may have contributed to lower sensitivity in detecting significant DEGs. While we have demonstrated hormonal control of CFTR expression in prior studies, 71 our CFTR changes here did not meet statistical significance even though expression changes trended in the same direction. There was a much closer association with E2 and P4 treated cells (Figure 4) than those in hormone-free culture, and as a hypothesis generating study, we analyzed a larger "hit" panel, recognizing that there will also be more false positives.…”

New Insights and Potential Therapeutic Interventions in Metabolic Diseases

“…Another example of a genetic metabolic disease is cystic fibrosis (CF), which is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene ( Figure 1 ) [ 60 ]. CFTR is a chloride channel that is involved in regulating ion transport across cell membranes, and mutations in this gene lead to abnormal fluid secretion in the lungs, pancreas, and other organs.…”

Changes of androgen and corticosterone metabolites excretion and conversion in cystic fibrosis

“…CFTR expression is multifactorially regulated, and many mechanisms (including hormonal control) cause tissue-specific regulation induced by this gene. A recent study has found that estrogens can increase the presence of CFTR in the uterine epithelium of the oviductal mucosa ( 4 , 5 ). Elements of the glucocorticoid response have been found in the CFTR promoter, and treatment with glucocorticoid changes the expression and activity of CFTR ( 6 ).…”