Role of metalloproteinases and their inhibitors in the development of abdominal aortic aneurysm: current insights and systematic review of the literature

INTRODUCTION: Abdominal aortic aneurysm (AAA) represents a widespread chronic degenerative condition of the aorta, which affects up to 9% of the general population over 65 years of age. Metalloproteinases, that are proteins that are capable to regulate extracellular matrix (ECM) structure and function, are known to play a pivotal role in the degradation of aortic ECM and, then, in the formation of aortic aneurysms. EVIDENCE ACQUISITION: Medline, Scopus and Science Direct were searched from January 2010 to March 2016 using the key word: “Abdominal aortic aneurysm and MMP,” “Abdominal aortic aneurysm and TIMP,” “Abdominal Aortic Aneurysm and ADAM” and “Abdominal aortic aneurysm and ADAMTS.” We also evaluated the reference lists of retrieved studies to identify studies that had not been identified at first. EVIDENCE SYNTHESIS: Of the 1917 records found, 316 matched our inclusion criteria. After reading the full-text articles, we decided to exclude 245 manuscripts because of the following reasons: 1) no innovative or important content; 2) no multivariable analysis; 3) insufficient data; 4) no clear potential biases or strategies to solve them; 5) no clear end-points; and 6) inconsistent or arbitrary conclusions. The final set included 71 articles. CONCLUSIONS: This review explores the three main families of metalloproteinases, Matrix Metalloproteinase (MMP), A Disintegrin and Metalloprotease (ADAM), A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) and their related tissue inhibitors of metalloproteinases (TIMP), showing their specific role in the field of AAAs.