TY - JOUR
T1 - Ano1, a Ca2+-activated Cl- channel, coordinates contractility in mouse intestine by Ca2+ transient coordination between interstitial cells of Cajal
AU - Singh, Raman Deep
AU - Gibbons, Simon J.
AU - Saravanaperumal, Siva Arumugam
AU - Du, Peng
AU - Hennig, Grant W.
AU - Eisenman, Seth T.
AU - Mazzone, Amelia
AU - Hayashi, Yujiro
AU - Cao, Chike
AU - Stoltz, Gary J.
AU - Ordog, Tamas
AU - Rock, Jason R.
AU - Harfe, Brian D.
AU - Szurszewski, Joseph H.
AU - Farrugia, Gianrico
N1 - Publisher Copyright:
© 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.
PY - 2014
Y1 - 2014
N2 - Interstitial cells of Cajal (ICC) are pacemaker cells that generate electrical activity to drive contractility in the gastrointestinal tract via ion channels.Ano1 (Tmem16a), aCa2+-activated Cl- channel, is an ion channel expressed in ICC. Genetic deletion of Ano1 in mice resulted in loss of slow waves in smooth muscle of small intestine. In this study, we show that Ano1 is required to maintain coordinated Ca2+ transients between myenteric ICC (ICC-MY) of small intestine. First, we found spontaneous Ca2+ transients in ICC-MY in both Ano1 WT and knockout (KO) mice. However, Ca2+ transients within the ICC-MY network in Ano1 KO mice were uncoordinated, while ICC-MY Ca2+ transients in Ano1 WT mice were rhythmic and coordinated. To confirm the role of Ano1 in the loss of Ca2+ transient coordination, we used pharmacological inhibitors of Ano1 activity and shRNA-mediated knock down of Ano1 expression in organotypic cultures of Ano1 WT small intestine. Coordinated Ca2+ transients became uncoordinated using both these approaches, supporting the conclusion that Ano1 is required to maintain coordination/rhythmicity of Ca2+ transients. We next determined the effect on smooth muscle contractility using spatiotemporal maps of contractile activity in Ano1 KO and WT tissues. Significantly decreased contractility that appeared to be non-rhythmic and uncoordinated was observed in Ano1 KO jejunum. In conclusion, Ano1 has a previously unidentified role in the regulation of coordinated gastrointestinal smooth muscle function through coordination of Ca2+ transients in ICC-MY.
AB - Interstitial cells of Cajal (ICC) are pacemaker cells that generate electrical activity to drive contractility in the gastrointestinal tract via ion channels.Ano1 (Tmem16a), aCa2+-activated Cl- channel, is an ion channel expressed in ICC. Genetic deletion of Ano1 in mice resulted in loss of slow waves in smooth muscle of small intestine. In this study, we show that Ano1 is required to maintain coordinated Ca2+ transients between myenteric ICC (ICC-MY) of small intestine. First, we found spontaneous Ca2+ transients in ICC-MY in both Ano1 WT and knockout (KO) mice. However, Ca2+ transients within the ICC-MY network in Ano1 KO mice were uncoordinated, while ICC-MY Ca2+ transients in Ano1 WT mice were rhythmic and coordinated. To confirm the role of Ano1 in the loss of Ca2+ transient coordination, we used pharmacological inhibitors of Ano1 activity and shRNA-mediated knock down of Ano1 expression in organotypic cultures of Ano1 WT small intestine. Coordinated Ca2+ transients became uncoordinated using both these approaches, supporting the conclusion that Ano1 is required to maintain coordination/rhythmicity of Ca2+ transients. We next determined the effect on smooth muscle contractility using spatiotemporal maps of contractile activity in Ano1 KO and WT tissues. Significantly decreased contractility that appeared to be non-rhythmic and uncoordinated was observed in Ano1 KO jejunum. In conclusion, Ano1 has a previously unidentified role in the regulation of coordinated gastrointestinal smooth muscle function through coordination of Ca2+ transients in ICC-MY.
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U2 - 10.1113/jphysiol.2014.277152
DO - 10.1113/jphysiol.2014.277152
M3 - Article
C2 - 25063822
AN - SCOPUS:84907851834
SN - 0022-3751
VL - 592
SP - 4051
EP - 4068
JO - Journal of Physiology
JF - Journal of Physiology
IS - 18
ER -