Loss of MURC/Cavin-4 induces JNK and MMP-9 activity enhancement in vascular smooth muscle cells and exacerbates abdominal aortic aneurysm

Biochem Biophys Res Commun. 2017 Jun 3;487(3):587-593. doi: 10.1016/j.bbrc.2017.04.096. Epub 2017 Apr 19.

Abstract

Abdominal aortic aneurysm (AAA) is relatively common in elderly patients with atherosclerosis. MURC (muscle-restricted coiled-coil protein)/Cavin-4 modulating the caveolae function of muscle cells is expressed in cardiomyocytes, skeletal muscle cells and smooth muscle cells. Here, we show a novel functional role of MURC/Cavin-4 in vascular smooth muscle cells (VSMCs) and AAA development. Both wild-type (WT) and MURC/Cavin-4 knockout (MURC-/-) mice subjected to periaortic application of CaCl2 developed AAAs. Six weeks after CaCl2 treatment, internal and external aortic diameters were significantly increased in MURC-/- AAAs compared with WT AAAs, which were accompanied by advanced fibrosis in the tunica media of MURC-/- AAAs. The activity of JNK and matrix metalloproteinase (MMP) -2 and -9 were increased in MURC-/- AAAs compared with WT AAAs at 5 days after CaCl2 treatment. At 6 weeks after CaCl2 treatment, MURC-/- AAAs exhibited attenuated JNK activity compared with WT AAAs. There was no difference in the activity of MMP-2 or -9 between saline and CaCl2 treatments. In MURC/Cavin-4-knockdown VSMCs, TNFα-induced activity of JNK and MMP-9 was enhanced compared with control VSMCs. Furthermore, WT, MURC-/-, apolipoprotein E-/- (ApoE-/-), and MURC/Cavin-4 and ApoE double-knockout (MURC-/-ApoE-/-) mice were subjected to angiotensin II (Ang II) infusion. In both ApoE-/- and MURC-/-ApoE-/- mice infused for 4 weeks with Ang II, AAAs were promoted. The internal aortic diameter was significantly increased in Ang II-infused MURC-/-ApoE-/- mice compared with Ang II-infused ApoE-/- mice. In MURC/Cavin-4-knockdown VSMCs, Ang II-induced activity of JNK and MMP-9 was enhanced compared with control VSMCs. Our results suggest that MURC/Cavin-4 in VSMCs modulates AAA progression at the early stage via the activation of JNK and MMP-9. MURC/Cavin-4 is a potential therapeutic target against AAA progression.

Keywords: Aneurysm; Angiotensin II; Caveolae; Jun amino-terminal kinases (JNK); Matrix metalloproteinase (MMP); Vascular smooth muscle cells (VSMCs).

MeSH terms

  • Animals
  • Aortic Aneurysm, Abdominal / metabolism*
  • Aortic Aneurysm, Abdominal / pathology
  • Apolipoproteins E / deficiency
  • Apolipoproteins E / metabolism
  • JNK Mitogen-Activated Protein Kinases / metabolism*
  • Matrix Metalloproteinase 9 / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Muscle Proteins / deficiency*
  • Muscle Proteins / metabolism*
  • Muscle, Smooth, Vascular / metabolism*
  • Muscle, Smooth, Vascular / pathology

Substances

  • Apolipoproteins E
  • Cavin4 protein, mouse
  • Muscle Proteins
  • JNK Mitogen-Activated Protein Kinases
  • Matrix Metalloproteinase 9