title: [Impact of stromal interaction molecule 1 silencing on cell cycle of endothelial progenitor cells].
abstract: OBJECTIVE
  To investigate the effect of stromal interaction molecule 1 (STIM1) silencing on EPCs cell cycle.
  
  
  METHODS
  Rat bone marrow derived endothelial progenitor cells (EPCs) were isolated and cultured in L-DMEM with 20% FBS. Ad-si/rSTIM1 and Ad-hSTIM1 were then transfected into EPCs and the expression of STIM1 mRNA was detected by RT-PCR. The cell cycle was determined using flow cytometry analysis and intracellular free Ca2+ was measured using LSCM. Co-immunoprecipitation was performed to examine the interaction between STIM1 and TRPC1. Protein levels of inositol 1, 4, 5-trisphosphate were analyzed with ELISA assay.
  
  
  RESULTS
  Forty-eight hours after transfection, the expression of STIM1 mRNA was significantly downregulated (0.37 +/- 0.02 vs. 1.00 +/- 0.02, P < 0.05) and intracellular free Ca2+ level was significantly reduced (34.07 +/- 4.10 vs. 86.51 +/- 14.12, P < 0.05) in Ad-si/rSTIM1 group compared with control group. The cell cycle was arrested at G1 phase [(90.91 +/- 1.10)% vs. (77.10 +/- 0.56)%, P < 0.05] and the store-operated channel entry was strikingly inhibited in EPCs after treatment with Ad-si/rSTIM1. However, cotransfection of Ad-hSTIM1 with Ad-si/rSTIM1 significantly reversed these responses. Interestingly, co-immunoprecipitation study showed that STIM1 co-precipitated with TRPC1, and IP3 levels measured by ELISA were similar among three groups (P > 0.05).
  
  
  CONCLUSIONS
  siRNA-mediated knockdown of STIM1 inhibited EPCs proliferation by reducing intracellular free Ca2+ through TRPC1-SOC signaling pathway.
authors.affiliation: Cardiovascular Research Institute of Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Kuang
authors.forename: Lan
authors.initials: L
authors.lastname: Huang
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.forename: Meng-Yang
authors.initials: MY
authors.lastname: Deng
authors.forename: Kui
authors.initials: K
authors.lastname: Wang
authors.forename: De-Hui
authors.initials: DH
authors.lastname: Qian
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D002453:Cell Cycle; D049109:Cell Proliferation; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology*; D020868:Gene Silencing; D005822:Genetic Vectors; D008565:Membrane Proteins / Q000235:genetics*; D009363:Neoplasm Proteins / Q000235:genetics*; D034741:RNA, Small Interfering; D051381:Rats; D013234:Stem Cells / Q000166:cytology*; D000071737:Stromal Interaction Molecule 1; D014162:Transfection; D050051:Transient Receptor Potential Channels / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D009363:Neoplasm Proteins; D034741:RNA, Small Interfering; C103530:STIM1 protein, human; D000071737:Stromal Interaction Molecule 1; D050051:Transient Receptor Potential Channels