Endophilin A2 Influences Volume-Regulated Chloride Current by Mediating ClC-3 Trafficking in Vascular Smooth Muscle Cells

Circ J. 2016 Oct 25;80(11):2397-2406. doi: 10.1253/circj.CJ-16-0793. Epub 2016 Oct 19.


Background: Previous research has demonstrated that ClC-3 is responsible for volume-regulated Cl-current (ICl.vol) in vascular smooth muscle cells (VSMCs). However, it is still not clear whether and how ClC-3 is transported to cell membranes, resulting in alteration ofICl.vol.Methods and Results:Volume-regulated chloride current (ICl.vol) was recorded by whole-cell patch clamp recording, and Western blotting and co-immunoprecipitation were performed to examine protein expression and protein-protein interaction. Live cell imaging was used to observe ClC-3 transporting. The results showed that an overexpression of endophilin A2 could increaseICl.vol, while endophilin A2 knockdown decreasedICl.vol. In addition, the SH3 domain of endophilin A2 mediated its interaction with ClC-3 and promotes ClC-3 transportation from the cytoplasm to cell membranes. The regulation of ClC-3 channel activity was also verified in basilar arterial smooth muscle cells (BASMCs) isolated from endophilin A2 transgenic mice. Moreover, endophilin A2 increase VSMCs proliferation induced by endothelin-1 or hypo-osmolarity.

Conclusions: The present study identified endophilin A2 as a ClC-3 channel partner, which serves as a new ClC-3 trafficking insight in regulatingICl.volin VSMCs. This study provides a new mechanism by which endophilin A2 regulates ClC-3 channel activity, and sheds light on how ClC-3 is transported to cell membranes to play its critical role as a chloride channel in VSMCs function, which may be involved in cardiovascular diseases. (Circ J 2016; 80: 2397-2406).

MeSH terms

  • Acyltransferases / genetics
  • Acyltransferases / metabolism*
  • Animals
  • Cell Membrane / genetics
  • Cell Membrane / metabolism*
  • Chloride Channels / genetics
  • Chloride Channels / metabolism*
  • Chlorides / metabolism*
  • Ion Transport
  • Membrane Potentials*
  • Mice
  • Mice, Knockout
  • Muscle, Smooth, Vascular / metabolism*
  • Myocytes, Smooth Muscle / metabolism*
  • Protein Transport


  • Chloride Channels
  • Chlorides
  • ClC-3 channel
  • Acyltransferases
  • 2-acylglycerophosphate acyltransferase