Multimodal imaging reveals temporal and spatial microglia and matrix metalloproteinase activity after experimental stroke

J Cereb Blood Flow Metab. 2015 Nov;35(11):1711-21. doi: 10.1038/jcbfm.2015.149. Epub 2015 Jul 1.

Abstract

Stroke is the most common cause of death and disability from neurologic disease in humans. Activation of microglia and matrix metalloproteinases (MMPs) is involved in positively and negatively affecting stroke outcome. Novel, noninvasive, multimodal imaging methods visualizing microglial and MMP alterations were employed. The spatio-temporal dynamics of these parameters were studied in relation to blood flow changes. Micro positron emission tomography (μPET) using [(18)F]BR-351 showed MMP activity within the first days after transient middle cerebral artery occlusion (tMCAo), followed by increased [(18)F]DPA-714 uptake as a marker for microglia activation with a maximum at 14 days after tMCAo. The inflammatory response was spatially located in the infarct core and in adjacent (penumbral) tissue. For the first time, multimodal imaging based on PET, single photon emission computed tomography, and magnetic resonance imaging revealed insight into the spatio-temporal distribution of critical parameters of poststroke inflammation. This allows further evaluation of novel treatment paradigms targeting the postischemic inflammation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Immunohistochemistry
  • Infarction, Middle Cerebral Artery / diagnostic imaging
  • Infarction, Middle Cerebral Artery / metabolism
  • Magnetic Resonance Imaging
  • Matrix Metalloproteinases / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Microglia / diagnostic imaging*
  • Microglia / pathology
  • Multimodal Imaging / methods*
  • Neuroimaging / methods*
  • Positron-Emission Tomography
  • Pyrazoles
  • Pyrimidines
  • Radiopharmaceuticals
  • Stroke / diagnostic imaging*
  • Stroke / enzymology*
  • Stroke / pathology
  • Technetium Tc 99m Exametazime
  • Tomography, Emission-Computed, Single-Photon

Substances

  • N,N-diethyl-2-(2-(4-(2-fluoroethoxy)phenyl)-5,7-dimethylpyrazolo(1,5-a)pyrimidin-3-yl)acetamide
  • Pyrazoles
  • Pyrimidines
  • Radiopharmaceuticals
  • Technetium Tc 99m Exametazime
  • Matrix Metalloproteinases