Depolarization of pacemaker potentials by caffeic acid phenethyl ester in interstitial cells of Cajal from the murine small intestine

2020 ◽  
Vol 98 (4) ◽  
pp. 201-210 ◽  
Author(s):  
Jeong Nam Kim ◽  
Byung Joo Kim

Interstitial cells of Cajal (ICCs) are pacemaker cells in the gastrointestinal (GI) tract and generate pacemaker potentials. In this study, we investigated the effects of caffeic acid phenethyl ester (CAPE) on the pacemaker potentials of ICCs from the mouse small or large intestine. Using the whole-cell patch-clamp configuration, we found that CAPE depolarized the pacemaker potentials of cultured ICCs from the murine small intestine in a dose-dependent manner. The estrogen receptor (ER) β antagonist PHTPP completely inhibited CAPE-induced depolarization, but the ERα antagonist BHPI did not. Intracellular GDP-β-S and pretreatment with Ca2+-free solution or thapsigargin also blocked CAPE-induced depolarization. To investigate the mechanisms of CAPE-mediated depolarization of ICCs, we used the nonselective cation channel (NSCC) inhibitor flufenamic acid, the Cl– channel blocker, mitogen-activated protein kinase (MAPK) inhibitors PD98059, SB203580, or SP600125, and PI3 kinase inhibitor LY294002. All inhibitors blocked the CAPE-induced pacemaker potential depolarization of ICCs. These results suggest that CAPE induces pacemaker potential depolarization through ERβ in a G protein, NSCC, Cl– channel, MAPK- and PI3 kinase dependent manner via intracellular and extracellular Ca2+ regulation in the murine small intestine. CAPE may therefore modulate GI motility by acting on ICCs in the murine small intestine.

2016 ◽  
Vol 38 (5) ◽  
pp. 1869-1882 ◽  
Author(s):  
Hyun Jung Kim ◽  
Jinhong Wie ◽  
Insuk So ◽  
Myeong Ho Jung ◽  
Ki-Tae Ha ◽  
...  

Background/Aims: ICCs are the pacemaker cells responsible for slow waves in gastrointestinal (GI) smooth muscle, and generate periodic pacemaker potentials in current-clamp mode. Methods: The effects of menthol on the pacemaker potentials of cultured interstitial cells of Cajal (ICCs) from mouse small intestine were studied using the whole cell patch clamp technique. Results: Menthol (1 - 10 μM) was found to induce membrane potential depolarization in a concentration-dependent manner. The effects of various TRP channel antagonists were examined to investigate the receptors involved. The addition of the TRPM8 antagonist, AMTB, did not block menthol-induced membrane potential depolarizations, but TRPA1 antagonists (A967079 or HC-030031) blocked the effects of menthol, as did intracellular GDPβS. Furthermore, external and internal Ca2+ levels were found to depolarize menthol-induced membrane potentials, whereas external Na+ was not. Y-27632 (a Rho kinase inhibitor), SC-560 (a selective COX 1 inhibitor), NS-398 (a selective COX 2 inhibitor), ozagrel (a thromboxane A2 synthase inhibitor) and SQ-29548 (highly selective thromboxane receptor antagonist) were used to investigate the involvements of Rho-kinase, cyclooxygenase (COX), and the thromboxane pathway in menthol-induced membrane potential depolarizations, and all inhibitors were found to block the effect of menthol. Conclusions: These results suggest that menthol-induced membrane potential depolarizations occur in a G-protein-, Ca2+-, Rho-kinase-, COX-, and thromboxane A2-dependent manner via TRPA1 receptor in cultured ICCs in murine small intestine. The study shows ICCs are targeted by menthol and that this interaction can affect intestinal motility.


Digestion ◽  
2019 ◽  
Vol 101 (3) ◽  
pp. 227-238 ◽  
Author(s):  
Jeong Nam Kim ◽  
Joo Hyun Nam ◽  
Jong Rok Lee ◽  
Sang Chan Kim ◽  
Young Kyu Kwon ◽  
...  

2015 ◽  
Vol 35 (6) ◽  
pp. 2422-2436 ◽  
Author(s):  
Huijin Gim ◽  
Joo Hyun Nam ◽  
Soojin Lee ◽  
Ji Hwan Shim ◽  
Hyun Jung Kim ◽  
...  

Background: Quercetin regulates gastrointestinal (GI) motor activity but the molecular mechanism involved has not been determined. The authors investigated the effects of quercetin, a flavonoid present in various foods, on the pacemaker activities of interstitial cells of Cajal (ICCs) in murine small intestine in vitro and on GI motility in vivo. Materials and Methods: Enzymatic digestion was used to dissociate ICCs from mouse small intestines. The whole-cell patch-clamp configuration was used to record pacemaker potentials in cultured ICCs in the absence or presence of quercetin and to record membrane currents of transient receptor potential melastatin (TRPM) 7 or transmembrane protein 16A (Tmem16A, anoctamin1 (ANO1)) overexpressed in human embryonic kidney (HEK) 293 cells. The in vivo effects of quercetin on GI motility were investigated by measuring the intestinal transit rates (ITRs) of Evans blue in normal mice. Results: Quercetin (100-200 μM) decreased the amplitudes and frequencies of pacemaker activity in a concentration-dependent manner in current clamp mode, but this action was blocked by naloxone (a pan-opioid receptor antagonist) and by GDPβS (a GTP-binding protein inhibitor). However, potassium channels were not involved in these inhibitory effects of quercetin. To study the quercetin signaling pathway, we examined the effects of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), an inhibitor of guanylate cyclase, and of RP-8-CPT-cGMPS, an inhibitor of protein kinase G (PKG). These inhibitors blocked the inhibitory effects of quercetin on pacemaker activities. Also, L-NAME (100 μM), a non-selective NO synthase (NOS) inhibitor, blocked the effects of quercetin on pacemaker activity and quercetin stimulated cGMP production. Furthermore, quercetin inhibited both Ca2+-activated Cl- channels (TMEM16A, ANO1) and TRPM7 channels. In vivo, quercetin (10-100 mg/kg, p.o.) decreased ITRs in normal mice in a dose-dependent manner. Conclusions: Quercetin inhibited ICC pacemaker activities by inhibiting TRPM7 and ANO1 via opioid receptor signaling pathways in cultured murine ICCs. The study shows quercetin attenuates GI tract motility, and suggests quercetin be considered the basis for the development of novel spasmolytic agents for the prevention or alleviation of GI motility dysfunctions.


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