Chlorogenic Acid Activates CFTR‐Mediated Cl^– Secretion in Mice and Humans

Abstract

Objectives Salubrious effects of the green coffee bean are purportedly secondary to high concentrations of chlorogenic acid. Chlorogenic acid has a molecular structure similar to bioflavonoids that activate transepithelial Cl- transport in sinonasal epithelia. In contrast to flavonoids, the drug is freely soluble in water. The objective of this study is to evaluate the Cl- secretory capability of chlorogenic acid and its potential as a therapeutic activator of mucus clearance in sinus disease. Study Design Basic research Setting Laboratory Subjects and Methods Chlorogenic acid was tested on primary murine nasal septal epithelial(MNSE)[CFTR+/+ and transgenic CFTR-/-] and human sinonasal epithelial(HSNE)[CFTR+/+ and F508del/F508del] cultures under pharmacologic conditions in Ussing chambers to evaluate effects on transepithelial Cl- transport. Cellular cAMP, phosphorylation of the CFTR regulatory domain(R-D), and CFTR mRNA transcription were also measured. Results Chlorogenic acid stimulated transepithelial Cl- secretion [(change in short-circuit current(ΔISC=μA/cm2)] in MNSE(13.1+/-0.9 vs. 0.1+/-0.1, p<0.05) and HSNE(34.3+/-0.9 vs. 0.0+/-0.1, p<0.05). The drug had a long duration until peak effect at 15-30 minutes after application. Significant inhibition with INH-172, as well as absent stimulation in cultures lacking functional CFTR, suggests effects are dependent on CFTR-mediated pathways. However, the absence of elevated cellular cAMP and phosphorylation the CFTR R-D indicates chlorogenic acid does not work through a PKA-dependent mechanism. Conclusion Chlorogenic acid is a water soluble agent that promotes CFTR-mediated Cl- transport in mouse and human sinonasal epithelium. Translating activators of mucociliary transport to clinical use provides a new therapeutic approach to sinus disease. Further in vivo evaluation is planned.

Characterization of primary rat nasal epithelial cultures in CFTR knockout rats as a model for CF sinus disease

“…With IACUC approval, the nasal septa of wild type (WT) (CFTR 1 / 1 ) and knockout (CFTR 2 / 2 ) rats were collected for this study using our previously described murine dissociation method and technique. 10,[32][33][34][35][36][37][38][39][40] Harvested tissue was subsequently transferred to 50-mL aliquots of dissociation media consisting of minimal essential medium (MEM) (Invitrogen, Carlsbad, California, U.S.A.); penicillin (60 IU/mL); streptomycin (60 lg/mL); 1.4 mg/mL Pronase (Roche Applied Science, Indianapolis, Indiana, U.S.A.); and 0.1 lg/mL DNase (Roche Applied Science), and then incubated in a 5% CO 2 chamber at 378C for 60 minutes, as previously described. 31 Termination of enzymatic dissociation was achieved using 5 mL of sterile 5% fetal bovine serum (Sigma Aldrich, St. Louis, Missouri, U.S.A.).…”

Innate immunity and chronic rhinosinusitis: What we have learned from animal models

“…The cystic fibrosis transmembrane conductance regulator (CFTR) mediates transepithelial Cl − transport, a critical step in regulating the viscosity of the ASL. In humans with mutations in the CFTR, mucous secretions become thick, resulting in poor mucociliary clearance and near universal CRS . As a single‐locus genetic disease, CF is an attractive condition to model by genetic manipulation in a laboratory animal.…”

“…Illing et al 32 Nasal septal epithelial cultures in vitro from CFTR 1/1 and CFTR -/mice were used to investigate chlorogenic acid-induced CFTR transport.…”

“…In humans with mutations in the CFTR, mucous secretions become thick, resulting in poor mucociliary clearance and near universal CRS. 32 As a single-locus genetic disease, CF is an attractive condition to model by genetic manipulation in a laboratory animal. Although CFTR mutations have been generated in mice, the outcome did not mirror the manifestations of CF in humans.…”

“…36 Although acquired defects in the CFTR may contribute to poor mucociliary clearance in human disease, augmenting the function of the CFTR to increase mucociliary clearance has been proposed as a potential therapeutic target and investigated using animal models. 32,39 Indeed, the small molecule resveratrol-stimulated CFTR-dependent Cl 2 ion secretion across the nasal epithelium in vivo, as assessed by nasal transepithelial potential difference. 24,40 Nasal septal epithelial cell cultures derived from mice can be a powerful model given the technology for targeted genetic manipulation.…”