NMMHC IIA inhibition impedes tissue factor expression and venous thrombosis via Akt/GSK3β-NF-κB signalling pathways in the endothelium

Thromb Haemost. 2015 Jul;114(1):173-85. doi: 10.1160/TH14-10-0880. Epub 2015 Apr 16.

Abstract

Non-muscle myosin heavy chain IIA (NMMHC IIA) has been shown to be involved in thrombus formation and inflammatory microparticle release in endothelial cells. However, the role of NMMHC IIA in regulating the expression of tissue factor (TF) and deep venous thrombosis remains to be elucidated. In the present study, endothelial cells were stimulated with tumour necrosis factor-α (TNF-α) to induce TF expression. Pretreatment with the NMMHC II inhibitor blebbistatin suppressed the mRNA and protein expressions as well as the procoagulant activity of TF in a dose-dependent manner. Blebbistatin enhanced Akt and GSK3β phosphorylation and inhibited NF-κB p65 nuclear translocation and IκBα degradation. These observations were similar to the effect of CHIR99021, a GSK3β inhibitor. TF downregulation by blebbistatin was antagonised by the PI3K inhibitor, wortmannin. Furthermore, siRNA knockdown of NMMHC IIA, but not IIB or IIC, inhibited TF expression, activated Akt/GSK3β and suppressed NF-κB signalling pathways, whereas the overexpression of NMMHC IIA increased TF expression. The binding of NMMHC IIA and TNF receptor 2 mediated signal internalisation in TNF-α-stimulated endothelial cells. Importantly, blebbistatin decreased endothelium NMMHC IIA and TF expression, deactivated GSK3β by inducing its phosphorylation, suppressed p65 nuclear translocation, and inhibited thrombus formation in a mouse deep venous thrombosis model.Our findings provide solid evidence that inhibition of NMMHC II, most likely NMMHC IIA, impedes TF expression and venous thrombosis via Akt/GSK3β-NF-κB signalling pathways in the endothelium both in vitro and in vivo. NMMHC IIA might be a potential novel target for the treatment of thrombotic disorders.

Keywords: NMMHC IIA; endothelium; signalling transduction; tissue factor; venous thrombosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Active Transport, Cell Nucleus
  • Animals
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Endothelial Cells / drug effects*
  • Endothelial Cells / enzymology
  • Fibrinolytic Agents / pharmacology*
  • Glycogen Synthase Kinase 3 / antagonists & inhibitors
  • Glycogen Synthase Kinase 3 / metabolism*
  • Glycogen Synthase Kinase 3 beta
  • HEK293 Cells
  • Heterocyclic Compounds, 4 or More Rings / pharmacology*
  • Humans
  • I-kappa B Proteins / metabolism
  • Mice, Inbred C57BL
  • Molecular Motor Proteins / antagonists & inhibitors*
  • Molecular Motor Proteins / genetics
  • Molecular Motor Proteins / metabolism
  • Myosin Heavy Chains / antagonists & inhibitors*
  • Myosin Heavy Chains / genetics
  • Myosin Heavy Chains / metabolism
  • NF-kappa B / metabolism*
  • Nonmuscle Myosin Type IIA / antagonists & inhibitors*
  • Nonmuscle Myosin Type IIA / genetics
  • Nonmuscle Myosin Type IIA / metabolism
  • Phosphorylation
  • Protein Kinase Inhibitors / pharmacology
  • Proto-Oncogene Proteins c-akt / antagonists & inhibitors
  • Proto-Oncogene Proteins c-akt / metabolism*
  • RNA Interference
  • Receptors, Tumor Necrosis Factor, Type II / metabolism
  • Signal Transduction / drug effects*
  • Thromboplastin / metabolism*
  • Transcription Factor RelA / metabolism
  • Transfection
  • Tumor Necrosis Factor-alpha / pharmacology
  • Venous Thrombosis / metabolism
  • Venous Thrombosis / prevention & control*

Substances

  • Fibrinolytic Agents
  • Heterocyclic Compounds, 4 or More Rings
  • I-kappa B Proteins
  • MYH9 protein, human
  • Molecular Motor Proteins
  • Myh9 protein, mouse
  • NF-kappa B
  • Protein Kinase Inhibitors
  • RELA protein, human
  • Receptors, Tumor Necrosis Factor, Type II
  • TNFRSF1B protein, human
  • Transcription Factor RelA
  • Tumor Necrosis Factor-alpha
  • blebbistatin
  • Thromboplastin
  • GSK3B protein, human
  • Glycogen Synthase Kinase 3 beta
  • Gsk3b protein, mouse
  • Proto-Oncogene Proteins c-akt
  • Glycogen Synthase Kinase 3
  • Nonmuscle Myosin Type IIA
  • Myosin Heavy Chains