VAMP8/endobrevin is overexpressed in hyperreactive human platelets: suggested role for platelet microRNA

J Thromb Haemost. 2010 Feb;8(2):369-78. doi: 10.1111/j.1538-7836.2009.03700.x. Epub 2009 Nov 23.


Background: Variation in platelet reactivity contributes to disorders of hemostasis and thrombosis, but the molecular mechanisms are not well understood.

Objectives: To discover associations between interindividual platelet variability and the responsible platelet genes, and to begin to define the molecular mechanisms altering platelet gene expression.

Subjects/methods: Two hundred and eighty-eight healthy subjects were phenotyped for platelet responsiveness. Platelet RNA from subjects demonstrating hyperreactivity (n=18) and hyporeactivity (n=11) was used to screen the human transcriptome.

Results: Distinctly different mRNA profiles were observed between subjects with differing platelet reactivity. Increased levels of mRNA for VAMP8/endobrevin, a critical v-SNARE involved in platelet granule secretion, were associated with platelet hyperreactivity (Q=0.0275). Validation studies of microarray results showed 4.8-fold higher mean VAMP8 mRNA levels in hyperreactive than hyporeactive platelets (P=0.0023). VAMP8 protein levels varied 13-fold among platelets from these normal subjects, and were 2.5-fold higher in hyperreactive platelets (P=0.05). Among our cohort of 288 subjects, a VAMP8 single-nucleotide polymorphism (rs1010) was associated with platelet reactivity in an age-dependent manner (P<0.003). MicroRNA-96 was predicted to bind to the 3'-untranslated regionof VAMP8 mRNA and was detected in platelets. Overexpression of microRNA-96 in VAMP8-expressing cell lines caused a dose-dependent decrease in VAMP8 protein and mRNA, suggesting a role in VAMP8 mRNA degradation.

Conclusions: These findings support a role for VAMP8/endobrevin in the heterogeneity of platelet reactivity, and suggest a role for microRNA-96 in the regulation of VAMP8 expression.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions
  • Adult
  • Age Factors
  • Binding Sites
  • Blood Platelets / metabolism*
  • Epinephrine
  • Female
  • Gene Expression Profiling / methods
  • Genotype
  • HCT116 Cells
  • Humans
  • Male
  • MicroRNAs / blood*
  • Oligonucleotide Array Sequence Analysis
  • Phenotype
  • Platelet Aggregation / genetics*
  • Polymorphism, Single Nucleotide*
  • R-SNARE Proteins / blood
  • R-SNARE Proteins / genetics*
  • RNA, Messenger / blood
  • Reproducibility of Results
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transfection
  • Up-Regulation
  • Young Adult


  • 3' Untranslated Regions
  • MIRN96 microRNA, human
  • MicroRNAs
  • R-SNARE Proteins
  • RNA, Messenger
  • VAMP8 protein, human
  • Epinephrine