Involvement of native TRPC3 proteins in ATP-dependent expression of VCAM-1 and monocyte adherence in coronary artery endothelial cells

Arterioscler Thromb Vasc Biol. 2008 Nov;28(11):2049-55. doi: 10.1161/ATVBAHA.108.175356. Epub 2008 Sep 11.


Background- Vascular cell adhesion molecule-1 (VCAM-1) is critical in monocyte recruitment to the endothelium, a key event in development of atherosclerotic lesions. Stimulation of human coronary artery endothelial cells (HCAECs) with ATP positively modulates VCAM-1 expression and function through a mechanism involving Ca(2+) signaling. We here examined the role of Ca(2+) influx and native TRPC3 channels in that mechanism.

Methods and results: Omission of extracellular Ca(2+) or pretreatment of cells with channel blockers markedly reduced ATP-induced VCAM-1 and monocyte adhesion. Using a siRNA strategy and real-time fluorescence, we found that native TRPC3 proteins contribute to constitutive and ATP-regulated Ca(2+) influx. ATP-dependent upregulation of VCAM-1 was accompanied by an increase in basal cation entry and TRPC3 expression. Notably, TRPC3 knock-down resulted in a dramatic reduction of ATP-induced VCAM-1 and monocyte adhesion.

Conclusions: These findings indicate that in HCAECs, native TRPC3 proteins form channels that contribute to constitutive and ATP-dependent Ca(2+) influx, and that TRPC3 expression and function are fundamental to support VCAM-1 expression and monocyte binding. This is the first evidence to date relating native TRPC3 proteins with regulated expression of cell adhesion molecules in coronary endothelium, and suggests a potential pathophysiological role of TRPC3 in coronary artery disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism*
  • Calcium Channel Blockers / pharmacology
  • Calcium Signaling* / drug effects
  • Cell Adhesion* / drug effects
  • Cells, Cultured
  • Coronary Artery Disease / metabolism
  • Coronary Vessels / drug effects
  • Coronary Vessels / metabolism*
  • Endothelial Cells / drug effects
  • Endothelial Cells / metabolism*
  • Humans
  • Monocytes / drug effects
  • Monocytes / metabolism*
  • RNA Interference
  • RNA, Small Interfering / metabolism
  • TRPC Cation Channels / genetics
  • TRPC Cation Channels / metabolism*
  • Time Factors
  • Tumor Necrosis Factor-alpha / metabolism
  • U937 Cells
  • Up-Regulation
  • Vascular Cell Adhesion Molecule-1 / metabolism*


  • Calcium Channel Blockers
  • RNA, Small Interfering
  • TRPC Cation Channels
  • TRPC3 cation channel
  • Tumor Necrosis Factor-alpha
  • Vascular Cell Adhesion Molecule-1
  • Adenosine Triphosphate