MMP‐12 knockout mouse: Is it a relevant animal model to study the role of MMP‐12 in post‐stroke brain damage?

Abstract

We recently reported for the first time the detrimental role of matrix metalloproteinase (MMP)‐12 on post‐stroke brain damage. We hypothesize that the post‐stroke MMPs dysregulation is similar across species and the genetic deletion of MMP‐12 does not affect the post‐stroke expression of other MMPs. We tested our hypothesis by determining the pre‐ and post‐ischemic expression profile of MMPs in MMP‐12 knockout and respective wild type mice. Focal cerebral ischemia was induced in MMP‐12 knockout and wild type mice by middle cerebral artery occlusion procedure by insertion of a monofilament suture. One hour after ischemia, reperfusion was initiated by removing the monofilament. One‐day after reperfusion, ischemic brain tissues from various groups of mice were collected for real‐time PCR analysis and PCR analysis followed by agarose gel electrophoresis. Although the post‐stroke regulation of several MMPs was altered in wild type mice, huge upregulation of MMP‐12 (~763 fold over sham) was noticed in mice similar to rats as reported earlier by our group. Unlike in rats, MMP‐8 was prominently upregulated (~280 fold over sham) in ischemic mice brains. As expected, MMP‐12 expression is absent in the ischemic brains of MMP‐12 knockout mice. Except the expression of MMP‐9, the expression of several other MMPs such as MMP‐1a, −2, −8, −10, −15, −16, −17, −21 and −28 was altered in the ischemic brain of MMP‐12 knockout mice as compared to wild type mice under similar experimental conditions. In addition, the expression of various MMPs in MMP‐12 knockout mice under non‐ischemic conditions was altered as compared to the wild type mice that did not subject to ischemia. Based on our results, we conclude that the mice with genetic deletion of MMP‐12 are constitutive in nature that warrants the attention of their use in elucidating the role of MMP‐12 in post‐stroke brain damage.Support or Funding InformationThis work was supported in part by the OSF HealthCare Foundation and OSF Illinois Neurological Institute, Peoria, IL.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.