Activation of Chloride Secretion by Isoflavone Genistein in Endometrial Epithelial Cells

Abstract

Background /Aim: Genistein, the most active isoflavone found primarily in soybeans, alters ion transport functions in intestinal and airway epithelia. The present study aims to investigate the acute effects and mechanisms of action of genistein in immortalized porcine endometrial epithelial cells. Methods: Ussing chamber technique was used for transepithelial electrical measurements. Results: Genistein increased short-circuit currents (I_sc) which were inhibited by glibenclamide, NPPB, CFTRinh-172, DIDS or bumetanide, but not amiloride. In experiments with amphotericin B-permeabilized monolayers, genistein activated the apical Cl^- current and barium-sensitive basolateral K⁺ current while inhibiting the apical K⁺ current. Genistein failed to increase the I_sc in the presence of forskolin or IBMX, but did increase the I_sc in UTP. Pretreatment with genistein also abolished the increase in the I_sc when induced by forskolin, IBMX or UTP. However, Ca²⁺-chelating BAPTA-AM did not affect the genistein-induced increase in the I_sc. The genistein-stimulated I_sc was reduced by tyrosine kinase inhibitors, tyrphostin A23 or AG490. However, vanadate, a tyrosine phosphatase inhibitor, failed to inhibit the genistein response. Estrogen receptor antagonist ICI182,780 did not alter the genistein's action. Conclusion: The soy isoflavone, genistein, stimulates Cl^- secretion in endometrial epithelial cells possibly via a direct activation of CFTR which appears to be modulated through a tyrosine kinase-dependent pathway. The present findings may be of benefit for the therapeutic application of genistein in the treatment of electrolyte transport disorders in the epithelia.

Soy isoflavones improves endometrial barrier through tight junction gene expression

“…This observation may correlate with our previous study demonstrating an acute effect of Ge on stimulation of chloride secretion in endometrial cells (Deachapunya & Poonyachoti 2013). Thus, the reduction in transcellular resistance caused by the opening of chloride ion-conductive pathway may account for the Ge-induced decrease in TER, albeit the TER is mainly dependent on the paracellular pathway (Madara et al 1988).…”

“…This study demonstrated that Ge and Di at specific concentrations affected the barrier function by alterations in TJ permeability in immortalized glandular epithelial monolayer, which have previously represented as an effective model for evaluating the effect of phytoestrogen on electrolyte transport (Deachapunya & Poonyachoti 2013). The underlying mechanism of these effects was thought to be relevant to alterations in TJ proteins, claudins, and ZO expression, as the genomic effects of these two isoflavonoids have been reported to affect the transcription level of these TJs proteins in intestinal epithelial cells (Suzuki & Hara 2009).…”

“…Since our recent study using the PEG cells that demonstrated the Ge stimulation of anion secretion via a tyrosine kinase-dependent pathway (Deachapunya & Poonyachoti 2013), it is possible that the tyrosine kinase-mediated phosphorylation of TJ protein is relevant to Ge effect on regulating TJs expression and function. The phosphorylation status of TJ protein has been suggested to determine TJs structure and function (Rao et al 1997).…”

“…In previous studies, the immortalized porcine glandular endometrial epithelial cell culture (PEG) was characterized and represented as the normal cell culture for examining the effects of Ge and Di on the epithelial function (Palmer et al 2008, Deachapunya & Poonyachoti 2013. Thus, in this study, we aimed to investigate whether the soy isoflavones, Ge or Di, alter the endometrial barrier function in the PEG cells as determined by TER and FITC-dextran flux (FD-4).…”

Nobiletin Stimulates Chloride Secretion in Human Bronchial Epithelia via a cAMP/PKA-Dependent Pathway

“…A similar stimulatory effect on CFTR channel activity was also observed by another citrus-derived flavonoid, tangeretin [7]. Because of its therapeutic potential in treating CF [41], the best-known and studied flavonoid, which can stimulate CFTR-dependent Cl - secretion, is genistein [42]. Genistein is a potent activator of CFTR and ∆F508 CFTR in human airway epithelial cell lines [43].…”