The non-excitable smooth muscle: calcium signaling and phenotypic switching during vascular disease

Pflugers Arch. 2008 Aug;456(5):769-85. doi: 10.1007/s00424-008-0491-8. Epub 2008 Mar 26.

Abstract

Calcium (Ca(2+)) is a highly versatile second messenger that controls vascular smooth muscle cell (VSMC) contraction, proliferation, and migration. By means of Ca(2+) permeable channels, Ca(2+) pumps and channels conducting other ions such as potassium and chloride, VSMC keep intracellular Ca(2+) levels under tight control. In healthy quiescent contractile VSMC, two important components of the Ca(2+) signaling pathways that regulate VSMC contraction are the plasma membrane voltage-operated Ca(2+) channel of the high voltage-activated type (L-type) and the sarcoplasmic reticulum Ca(2+) release channel, Ryanodine Receptor (RyR). Injury to the vessel wall is accompanied by VSMC phenotype switch from a contractile quiescent to a proliferative motile phenotype (synthetic phenotype) and by alteration of many components of VSMC Ca(2+) signaling pathways. Specifically, this switch that culminates in a VSMC phenotype reminiscent of a non-excitable cell is characterized by loss of L-type channels expression and increased expression of the low voltage-activated (T-type) Ca(2+) channels and the canonical transient receptor potential (TRPC) channels. The expression levels of intracellular Ca(2+) release channels, pumps and Ca(2+)-activated proteins are also altered: the proliferative VSMC lose the RyR3 and the sarcoplasmic/endoplasmic reticulum Ca(2+) ATPase isoform 2a pump and reciprocally regulate isoforms of the ca(2+)/calmodulin-dependent protein kinase II. This review focuses on the changes in expression of Ca(2+) signaling proteins associated with VSMC proliferation both in vitro and in vivo. The physiological implications of the altered expression of these Ca(2+) signaling molecules, their contribution to VSMC dysfunction during vascular disease and their potential as targets for drug therapy will be discussed.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Calcium Channels / metabolism
  • Calcium Signaling / physiology*
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2 / metabolism
  • Inositol 1,4,5-Trisphosphate Receptors / metabolism
  • Muscle Contraction / physiology
  • Muscle, Smooth / cytology
  • Muscle, Smooth / physiology*
  • Myocytes, Smooth Muscle / physiology*
  • Phenotype*
  • Plasma Membrane Calcium-Transporting ATPases / metabolism
  • Potassium Channels / metabolism
  • Ryanodine Receptor Calcium Release Channel / metabolism
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases / metabolism
  • TRPC Cation Channels / metabolism
  • Vascular Diseases / physiopathology*

Substances

  • Calcium Channels
  • Inositol 1,4,5-Trisphosphate Receptors
  • Potassium Channels
  • Ryanodine Receptor Calcium Release Channel
  • TRPC Cation Channels
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2
  • Plasma Membrane Calcium-Transporting ATPases
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases
  • Calcium