Vasogenic edema due to tight junction disruption by matrix metalloproteinases in cerebral ischemia.
Level 5 - mechanism / opinion, no new human data
Narrative review of preclinical and mechanistic literature with no primary human data
PubMed 17613235 · doi:10.3171/foc.2007.22.5.5
What was done
This is a narrative review detailing the molecular mechanisms of blood-brain barrier (BBB) breakdown and vasogenic edema in cerebral ischemia, focusing on the roles of matrix metalloproteinases (MMPs), tight junction proteins, and basal lamina degradation.
What was found
The abstract reports no quantitative data or sample sizes. It describes a biphasic opening of the BBB after reperfusion injury: an early transient opening occurring several hours post-reperfusion mediated by constitutive MMP-2 (gelatinase A), followed 24 to 48 hours later by more severe damage driven by MMP-9 (gelatinase B) and MMP-3 (stromelysin-1). These proteases degrade tight junction proteins (occludin, claudin-5) and basal lamina components. Synthetic MMP inhibitors mitigate early BBB breakdown but fail during the late phase and impair recovery by halting MMP-dependent angiogenesis and neurogenesis.
Why it matters
It highlights the biphasic temporal dynamics of ischemic vascular injury and the therapeutic challenge of blocking vasogenic edema without compromising late neurovascular repair.
Limits
The abstract contains no primary human data, quantitative outcomes, or systematic literature search methodology, relying entirely on mechanistic and preclinical findings.
Cited by
- context Following an ischemic stroke, there is a biphasic breakdown of the blood-brain barrier at 2 hours and 3 days that correlates with two peaks of MMP-9 expression.