White matter damage and the effect of matrix metalloproteinases in type 2 diabetic mice after stroke

Jieli Chen1, Xu Cui, Alex Zacharek

  • 1Neurology Research, Henry Ford Hospital, Detroit, MI 48202, USA. jieli@neuro.hfh.edu

Stroke
|January 4, 2011
PubMed
Abstract

Insights

Diabetes mellitus exacerbates stroke outcomes, causing more severe white matter damage and brain hemorrhage in mice. Increased matrix metalloproteinase-9 (MMP-9) activity appears to worsen this white matter injury after stroke.

Area of Science:

  • Neuroscience
  • Endocrinology
  • Pathology

Background:

  • Diabetes mellitus is a known risk factor for ischemic stroke, leading to poorer patient outcomes.
  • Limited research exists on the specific impact of diabetes on white matter (WM) damage post-stroke.

Purpose of the Study:

  • To investigate the extent and mechanisms of white matter damage in mice with diabetes mellitus following stroke.

Main Methods:

  • Utilized type 2 diabetes mellitus mice (db/db) and non-diabetic controls, subjected to middle cerebral artery occlusion (MCAO).
  • Assessed functional outcomes, performed immunostaining, zymography, Western blot, and PCR.
  • Employed in vitro cultures of oligodendrocytes and cortical neurons under high glucose conditions.

Main Results:

  • Diabetic mice showed larger lesion volumes, increased brain hemorrhage, and worsened neurological deficits post-stroke.
  • Significant reductions in WM markers (Bielshowsky silver, luxol fast blue, APP, NG2) and elevated matrix metalloproteinase-9 (MMP-9) activity were observed in diabetic stroke brains.
  • In vitro, high glucose increased apoptosis and MMP levels in neurons and oligodendrocytes, while MMP inhibition reduced cell death.

Conclusions:

  • Diabetes mellitus significantly increases brain hemorrhage and exacerbates white matter injury after stroke in mice.
  • Upregulation of MMP-9 in diabetic conditions may be a key factor contributing to more severe white matter damage post-stroke.

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