Immunohistochemistry of matrix metalloproteinases in reperfusion injury to rat brain: activation of MMP-9 linked to stromelysin-1 and microglia in cell cultures
Abstract
Reperfusion damages the blood-brain barrier (BBB). Matrix metalloproteinases (MMPs) are associated with the opening of the BBB, but their cellular localization and activation mechanisms are uncertain. We used immunohistochemistry to determine the cellular localization of the MMPs in reperfused rat brain, and cell cultures to study their activation. Spontaneously hypertensive rats (SHR) had a 90 min middle cerebral artery occlusion (MCAO) followed by reperfusion for times from 3 h to 21 days. Frozen sections were immunostained with antibodies to gelatinase A (MMP-2), stromelysin-1 (MMP-3), and gelatinase B (MMP-9). Sham-operated control rats showed MMP-2 immunostaining in astrocytic processes next to blood vessels. After 3 h of the onset of reperfusion MMP-2 immunostaining increased in astrocytes. At 24 h immunoreactivity for MMP-3 and MMP-9 appeared. MMP-3 co-localized with activated microglia (Ox-42+) and ischemic neurons (NeuN+). MMP-9 immunostaining was seen at 48 h in endothelial cells, neutrophils, and neurons. At 5 and 21 days intense MMP-2 staining was seen in reactive astrocytes around the ischemic core. Studies of activation of the MMP were done in lipopolysaccharide (LPS)-stimulated astrocyte and microglia cultures. Stimulated astrocytes produced an activated form of MMP-2. When microglia were stimulated, they activated MMP-9. Immunostaining showed MMP-3 in cultures of enriched microglial cells. The hydroxymate-type, MMP inhibitor, BB-1101, blocked the activation of MMP-2 and MMP-9 by LPS in mixed glial cultures. We propose that MMP-2 is normally present in astrocytic end feet, and that during ischemia MMP-9 and MMP-3 are produced. MMP-3 in microglia/macrophages may be activating proMMP-9. Our results show that a differential expression of MMPs by astrocytes, microglia, and endothelial cells at the blood vessels is involved in the proteolytic disruption of the BBB.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
In the delayed phase, microglial ROS, especially superoxide radical O2−, increase vascular permeability by stimulating MMP-2/MMP-3/MMP-9 production by microglia, astrocytes and endothelial cells, contributing to hemorrhagic transformation and vasogenic edema.
“In this phase, MMPs are important mediators: microglial ROS, especially superoxide radical O2−, increase vascular permeability also by stimulating MMP-2/MMP-3/MMP-9 production by microglia, astrocytes and ECs (Gottschall and Deb, 1996; Asahi et al., 2001; Rosenberg et al., 2001), contributing to hemorrhagic transformation and vasogenic edema.”
From The impact of microglial activation on blood-brain barrier in brain diseases (2014) · cites this paper as Rosenberg et al., 2001
The citation lists haven’t been fetched yet
References 23 · Cited by 388
- Authors
- Rosenberg, G. A., Cunningham, L. A., Wallace, J., Alexander, S., Estrada, E. Y., Grossetete, M., Razhagi, A., Miller, K., & Gearing, A.
- Affiliations
- University of New Mexico (US)
- Corresponding author
- Rosenberg, Gary A.
- Venue
- Brain Research
- Publisher
- Elsevier BV
- Published
- 2001-03
- Volume
- 893
- Issue
- 1-2
- Pages
- 104-112
- ISSN
- 0006-8993 (ISSN-L)
- OpenAlex
- W2090459889
- Cited by
- 388
- References
- 23
- Citations by year
- 2026: 4 · 2025: 5 · 2024: 2 · 2023: 2 · 2022: 9 · 2021: 14 · 2020: 5 · 2019: 10 · 2018: 7 · 2017: 11 · 2016: 11 · 2015: 19 · 2014: 16 · 2013: 20 · 2012: 26
- FWCI
- 8.33
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Brain Research (publishedVersion)
- PubMed (publishedVersion)
- Funders
- National Institutes of Health (5r01ns038655-03)
- National Institute of Neurological Disorders and Stroke (R01NS21169, R01 NS38655, R01NS021169)
- Topics
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Cancer Research › Protease and Inhibitor Mechanisms
- Life Sciences › Neuroscience › Neurology › Barrier Structure and Function Studies
- Life Sciences › Neuroscience › Neurology › Neuroinflammation and Neurodegeneration Mechanisms
- Keywords
- matrix metalloproteinases, ischemia-reperfusion injury, blood-brain barrier disruption, MMP-9, MMP-2, MMP-3, stromelysin-1, microglia, astrocytes, endothelial cells, neutrophils, ischemic stroke, middle cerebral artery occlusion, lipopolysaccharide stimulation
- MeSH terms
- Animals, Antigens, Neoplasm, Antigens, Surface, Blood Proteins, Blood-Brain Barrier, Brain, Cells, Cultured, Brain Ischemia, Enzyme Activation, Glial Fibrillary Acidic Protein, Immunohistochemistry, Membrane Glycoproteins, Rats, Inbred SHR, Reperfusion Injury, Antigens, CD, Rats, Sprague-Dawley, Microglia, Matrix Metalloproteinase 3, Matrix Metalloproteinase 2, Matrix Metalloproteinase 9, Matrix Metalloproteinases, Avian Proteins, Rats, Basigin
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
