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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2009-1-19
pubmed:abstractText
Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases involved in brain development and the etiology of adult cerebral injuries. In this study, we determined the MMP-2 and 9 responses following hypoxic ischemia (HI) injury in the developing brain. First, we characterized the developmental changes of MMP activity in the rat brain from embryonic day 18 (E18) to postnatal day 120 (P120). MMP-2 activity was high from E18 to P3 and decreased with age (P< or =0.001), while MMP-9 activity was not detectable. MMP-2 immunoreactivity was closely associated with differentiating cortical plate and subplate neurons. Next, we characterized the proteolytic changes after unilateral HI brain injury in 3- (P3) and 21- (P21) day-old rats. Zymography revealed that in the P21 rat brain, MMP-9 activity (150 and 92 kDa forms) was increased at 6 h and remained elevated 24 h post-injury in the ipsilateral injured hemisphere (P< or =0.001), whereas there was a gradual increase in MMP-2 (65 kDa) activity, reaching a peak at 5 days (P< or =0.001). Similarly, quantitative real time polymerase chain reaction (qRT-PCR) indicated significant elevations in MMP-9 and MMP-2 mRNA expression in the injured cortex (P< or =0.05) and hippocampus (P< or =0.05) at 1 and 5 days post-injury, respectively in the P21 rat brain. In the P3 rat brain, zymography results revealed that both pro (92 kDa) and cleaved (87 kDa) MMP-9 activities were upregulated in the ipsilateral injured hemisphere from 6 h to 1 day after injury (P< or =0.001). In contrast, cleaved MMP-2 (60 kDa) was only moderately upregulated at 6 h (P< or =0.01), while pro MMP-2 (65 kDa) levels were unaffected. MMP-9 mRNA expression was also increased at 6 h (P< or =0.05) following injury at P3, whereas MMP-2 expression remained unchanged compared with the uninjured contralateral hemisphere. Immunohistochemistry indicated that MMP-9 protein expression was localized predominantly to neurons and peri-vascular astrocytes in the affected regions at early time points, whereas MMP-2 was present on reactive astrocytes surrounding the infarct at later time points. Together, these results indicate that MMP-2 may be primarily associated with the development and differentiation of cortical plate neurons and wound recovery processes. Conversely, MMP-9 appeared to be associated with more acute processes during the period of lesion development.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
158
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
732-44
pubmed:meshHeading
pubmed-meshheading:18809469-Age Factors, pubmed-meshheading:18809469-Analysis of Variance, pubmed-meshheading:18809469-Animals, pubmed-meshheading:18809469-Animals, Newborn, pubmed-meshheading:18809469-Cerebral Cortex, pubmed-meshheading:18809469-Disease Models, Animal, pubmed-meshheading:18809469-Embryo, Mammalian, pubmed-meshheading:18809469-Female, pubmed-meshheading:18809469-GAP-43 Protein, pubmed-meshheading:18809469-Gene Expression Regulation, Developmental, pubmed-meshheading:18809469-Glial Fibrillary Acidic Protein, pubmed-meshheading:18809469-Hypoxia-Ischemia, Brain, pubmed-meshheading:18809469-Male, pubmed-meshheading:18809469-Matrix Metalloproteinase 2, pubmed-meshheading:18809469-Matrix Metalloproteinase 9, pubmed-meshheading:18809469-Phosphopyruvate Hydratase, pubmed-meshheading:18809469-Pregnancy, pubmed-meshheading:18809469-Rats, pubmed-meshheading:18809469-Rats, Wistar, pubmed-meshheading:18809469-Time Factors
pubmed:year
2009
pubmed:articleTitle
Proteolytic activity during cortical development is distinct from that involved in hypoxic ischemic injury.
pubmed:affiliation
Liggins Institute, University of Auckland, 2-6 Park Avenue, Grafton, Auckland, New Zealand.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't