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Relaxin and Matrix Metalloproteinase-9 in Angiotensin II-Induced Abdominal Aortic Aneurysms

Deborah A Howatt1, Maya Dajee2, Xiaojie Xie1,3

  • 1Saha Cardiovascular Research Center, University of Kentucky.

Circulation Journal : Official Journal of the Japanese Circulation Society
|April 20, 2017
PubMed
Abstract

Insights

Matrix metalloproteinase-9 (MMP-9) deficiency augmented angiotensin II-induced abdominal aortic aneurysms (AAA). Relaxin did not influence AAA, but affected MMP-9 expression in macrophages.

Area of Science:

  • Cardiovascular Research
  • Vascular Biology
  • Biochemistry

Background:

  • Abdominal aortic aneurysms (AAA) are a significant cause of mortality.
  • The roles of relaxin and matrix metalloproteinase-9 (MMP-9) in AAA pathogenesis are not fully understood.

Purpose of the Study:

  • To investigate the influence of relaxin and MMP-9 on angiotensin II (AngII)-induced AAA.
  • To elucidate the specific mechanisms by which these factors affect AAA development.

Main Methods:

  • AngII infusion in male C57BL/6 and apolipoprotein E knockout mice, with or without relaxin administration.
  • Analysis of MMP-9 mRNA expression in macrophages.
  • Assessment of AAA incidence and aortic rupture in MMP-9 deficient mice.

Main Results:

  • Relaxin did not affect AngII-induced AAA formation in either mouse strain.
  • AngII infusion decreased MMP-9 mRNA, while relaxin increased it in macrophages.
  • MMP-9 deficiency led to AAA formation without AngII and worsened AngII-induced aortic rupture and AAA incidence.

Conclusions:

  • MMP-9 deficiency significantly augmented AngII-induced AAA.
  • These findings highlight a critical role for MMP-9 in AAA progression and suggest potential therapeutic targets.
Keywords:
Abdominal aortic aneurysmMatrix metalloproteinaseRelaxin

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