Conditional genetic deletion of Ano1 in interstitial cells of Cajal impairs Ca 2+ transients and slow waves in adult mouse small intestine

作者：John Malysz, Simon J. Gibbons, Siva Arumugam Saravanaperumal, Peng Du, Seth T. Eisenman, Chike Cao, Uhtaek Oh, Dieter Saur, Sabine Klein, Tamás Ördög, Gianrico Farrugia · 发表于：American Journal of Physiology-Gastrointestinal and Liver Physiology · 年份：2016 · DOI：10.1152/ajpgi.00363.2016 · 被引用次数：91 · 研究领域：Gastrointestinal motility and disorders、Ion Transport and Channel Regulation、Diet and metabolism studies

Myenteric plexus interstitial cells of Cajal (ICC-MY) in the small intestine are Kit + electrical pacemakers that express the Ano1/TMEM16A Ca 2+ -activated Cl – channel, whose functions in the gastrointestinal tract remain incompletely understood. In this study, an inducible Cre-LoxP-based approach was used to advance the understanding of Ano1 in ICC-MY of adult mouse small intestine. Kit CreERT2/+ ;Ano1 Fl/Fl mice were treated with tamoxifen or vehicle, and small intestines (mucosa free) were examined. Quantitative RT-PCR demonstrated ~50% reduction in Ano1 mRNA in intestines of conditional knockouts (cKOs) compared with vehicle-treated controls. Whole mount immunohistochemistry showed a mosaic/patchy pattern loss of Ano1 protein in ICC networks. Ca 2+ transients in ICC-MY network of cKOs displayed reduced duration compared with highly synchronized controls and showed synchronized and desynchronized profiles. When matched, the rank order for Ano1 expression in Ca 2+ signal imaged fields of view was as follows: vehicle controls>>>cKO(synchronized)>cKO(desynchronized). Maintenance of Ca 2+ transients’ synchronicity despite high loss of Ano1 indicates a large functional reserve of Ano1 in the ICC-MY network. Slow waves in cKOs displayed reduced duration and increased inter-slow-wave interval and occurred in regular- and irregular-amplitude oscillating patterns. The latter activity suggested ongoing interaction by independent interacting oscillators. Lack of slow wav...