Tissue Inhibitor of Metalloproteinase-3 (TIMP-3) induces FAS dependent apoptosis in human vascular smooth muscle cells

PLoS One. 2018 Apr 4;13(4):e0195116. doi: 10.1371/journal.pone.0195116. eCollection 2018.

Abstract

Over expression of Tissue Inhibitor of Metalloproteinases-3 (TIMP-3) in vascular smooth muscle cells (VSMCs) induces apoptosis and reduces neointima formation occurring after saphenous vein interposition grafting or coronary stenting. In studies to address the mechanism of TIMP-3-driven apoptosis in human VSMCs we find that TIMP-3 increased activation of caspase-8 and apoptosis was inhibited by expression of Cytokine response modifier A (CrmA) and dominant negative FAS-Associated protein with Death Domain (FADD). TIMP-3 induced apoptosis did not cause mitochondrial depolarisation, increase activation of caspase-9 and was not inhibited by over-expression of B-cell Lymphoma 2 (Bcl2), indicating a mitochondrial independent/type-I death receptor pathway. TIMP-3 increased levels of the First Apoptosis Signal receptor (FAS) and depletion of FAS with shRNA showed TIMP-3-induced apoptosis was FAS dependent. TIMP-3 induced formation of the Death-Inducing Signalling Complex (DISC), as detected by immunoprecipitation and by immunofluorescence. Cellular-FADD-like IL-1 converting enzyme-Like Inhibitory Protein (c-FLIP) localised with FAS at the cell periphery in the absence of TIMP-3 and this localisation was lost on TIMP-3 expression with c-FLIP adopting a perinuclear localisation. Although TIMP-3 inhibited FAS shedding, this did not increase total surface levels of FAS but instead increased FAS levels within localised regions at the cell surface. A Disintegrin And Metalloproteinase 17 (ADAM17) is inhibited by TIMP-3 and depletion of ADAM17 with shRNA significantly decreased FAS shedding. However ADAM17 depletion did not induce apoptosis or replicate the effects of TIMP-3 by increasing localised clustering of cell surface FAS. ADAM17-depleted cells could activate caspase-3 when expressing levels of TIMP-3 that were otherwise sub-apoptotic, suggesting a partial role for ADAM17 mediated ectodomain shedding in TIMP-3 mediated apoptosis. We conclude that TIMP-3 induced apoptosis in VSMCs is highly dependent on FAS and is associated with changes in FAS and c-FLIP localisation, but is not solely dependent on shedding of the FAS ectodomain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADAM17 Protein / antagonists & inhibitors
  • ADAM17 Protein / genetics
  • ADAM17 Protein / metabolism
  • Apoptosis* / drug effects
  • CASP8 and FADD-Like Apoptosis Regulating Protein / metabolism
  • Caspases / metabolism
  • Cells, Cultured
  • Disintegrins / antagonists & inhibitors
  • Disintegrins / metabolism
  • Humans
  • Membrane Potential, Mitochondrial / drug effects
  • Microscopy, Confocal
  • Muscle, Smooth, Vascular / cytology
  • Muscle, Smooth, Vascular / metabolism
  • RNA Interference
  • RNA, Small Interfering / metabolism
  • Staurosporine / pharmacology
  • Tissue Inhibitor of Metalloproteinase-3 / genetics
  • Tissue Inhibitor of Metalloproteinase-3 / metabolism*
  • fas Receptor / antagonists & inhibitors
  • fas Receptor / genetics
  • fas Receptor / metabolism*

Substances

  • CASP8 and FADD-Like Apoptosis Regulating Protein
  • Disintegrins
  • FAS protein, human
  • RNA, Small Interfering
  • Tissue Inhibitor of Metalloproteinase-3
  • fas Receptor
  • Caspases
  • ADAM17 Protein
  • Staurosporine