Expression of protease-activated receptors (PARs) in OLN-93 oligodendroglial cells and mechanism of PAR-1-induced calcium signaling

Yingfei Wang, C. Richter-Landsberg, G. Reiser

Research output: Contribution to journalArticle

34 Scopus citations

Abstract

Protease-activated receptors (PARs) are a group of four members of the superfamily of G protein-coupled receptors that transduce cell signaling by proteolytic activity of extracellular serine proteases, such as thrombin. Possible expression and functions of PARs in oligodendrocytes, the myelin forming cells of the CNS, are still unclear. Here, the oligodendrocyte cell line OLN-93 was used to investigate the signaling of PARs. By reverse transcription-polymerase chain reaction (RT-PCR), immunostaining and Ca 2+ imaging studies, we demonstrate that OLN-93 cells functionally express PAR-1. PAR-3 seems to be expressed without apparent activity, and PAR-2 and PAR-4 cannot be detected. Short-term stimulation of the OLN-93 cells with PAR-1 agonists, such as thrombin, trypsin and PAR-1 activating peptide, dose-dependently induced a transient rise of [Ca2+]i. Concentration-effect curves display a sigmoidal concentration dependence. Elevation of [Ca2+]i induced by PAR-1 mainly resulted from Ca2+ release from intracellular stores. Studies on the effects of pertussis toxin (PTX), phospholipase C antagonist and 2-APB, showed that in OLN-93 cells (i) the calcium signaling cascade from PAR-1 was mediated through PTX-insensitive G proteins, (ii) activation of phospholipase C and liberation of InsP3 were events upstream of the Ca2+ release from the stores. In addition, the present study analyzed PAR-1 desensitization caused by exposure to thrombin, trypsin, and PAR-1 activating peptide, elucidated the influence of the protease cathepsin G on PAR-1 activation, and also characterized PAR-1 desensitization. This is the first study, which shows that OLN-93 oligodendrocytes functionally express PAR-1, and identifies the receptor coupling to mobilization of intracellular calcium. Moreover, the expression of PAR-1 was demonstrated by RT-PCR in primary oligodendrocytes from rat brain.

Original languageEnglish (US)
Pages (from-to)69-82
Number of pages14
JournalNeuroscience
Volume126
Issue number1
DOIs
StatePublished - May 24 2004

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Keywords

  • 2′,3′-cyclic nucleotide 3′-phosphodiesterase
  • AP
  • CNP
  • DMEM
  • Dulbecco's Modified Eagle medium
  • GAPDH
  • activating peptide
  • base pair
  • bp
  • calcium signaling
  • cathepsin G
  • protease-activated receptors
  • thrombin
  • trypsin

ASJC Scopus subject areas

  • Neuroscience(all)

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