5-lipoxygenase inhibitor zileuton attenuates ischemic brain damage: involvement of matrix metalloproteinase 9

Matrix metalloproteinase-9 (MMP-9) activity increases in the brain during the first day after focal ischemia and might be involved in the pathogenesis of tissue damage. We previously showed MMP-9 in the extracellular space of brain parenchyma along with neutrophil recruitment after ischemia. In the present study, we tested whether neutrophils were a direct source of enhanced MMP-9 in the ischemic brain. Neutrophil infiltration was prevented either by injecting an antibody against ICAM-1, which abrogates neutrophil adhesion to the endothelial vessel wall, or by inducing neutropenia. One-hour intraluminal middle cerebral artery occlusion with reperfusion was induced, and studies were performed at 24 hours. Circulating neutrophils expressed 95-kDa MMP-9 and dimers, and infiltrated neutrophils stained positive for MMP-9. The expression of MMP-9 (mainly 95-kDa proform and dimers and, to a lesser extent, 88-kDa form) increased in brain after ischemia/reperfusion. Treatments preventing neutrophil infiltration failed to preclude the ischemia-induced increase in 88-kDa MMP-9 form and gelatinase activity in neurons and blood vessels. However, these treatments prevented the major increase in 95-kDa MMP-9 form and dimers. We conclude that neutrophil infiltration highly contributes to enhanced MMP-9 in the ischemic brain by releasing MMP-9 proform, which might participate in the tissular inflammatory reaction.

Download Full-text

Matrix Metalloproteinase-9 Levels are Associated with Brain Lesion and Persistent Venous Occlusion in Patients with Cerebral Venous Thrombosis

Thrombosis and Haemostasis ◽

10.1055/s-0041-1726094 ◽

2021 ◽

Author(s):

Diana Aguiar de Sousa ◽

Maria Conceição Pereira-Santos ◽

Ana Serra-Caetano ◽

Lia Lucas Neto ◽

Ana Luísa Sousa ◽

...

Keyword(s):

Matrix Metalloproteinase ◽

Venous Thrombosis ◽

Brain Damage ◽

Cerebral Venous Thrombosis ◽

Brain Lesion ◽

Venous Occlusion ◽

Matrix Metalloproteinase 9 ◽

Enzyme Linked Immunosorbent Assay ◽

Venous Recanalization ◽

Metalloproteinase 9

Abstract Background Elucidating mechanisms of brain damage in cerebral venous thrombosis (CVT) would be instrumental to develop targeted therapies and improve prognosis prediction. Matrix metalloproteinase-9 (MMP-9), a gelatinase that degrades major components of the basal lamina, has been associated to blood–brain barrier disruption. We aimed to assess, in patients with CVT, the temporal change in serum concentrations of MMP-9 and its association with key imaging and clinical outcomes. Methods Pathophysiology of Venous Infarction—PRediction of InfarctiOn and RecanalIzaTion in CVT (PRIORITy-CVT) was a multicenter prospective cohort study of patients with newly diagnosed CVT. Serial collection of peripheral blood samples performed on day 1, 3, and 8, and standardized magnetic resonance imaging on day 1, 8, and 90. MMP-9 was quantified using enzyme-linked immunosorbent assay in 59 patients and 22 healthy controls. Primary outcomes were parenchymal brain lesion, early evolution of brain lesion, early recanalization, and functional outcome on day 90. Results CVT patients with parenchymal brain lesion had higher baseline concentrations of MMP-9 compared with controls (adjusted p = 0.001). The area under receiver operating characteristic curve value for MMP-9 for predicting brain lesion was 0.71 (95% confidence interval [CI]: 0.57–0.85, p = 0.009). Patients with venous recanalization showed early decline of circulating MMP-9 and significantly lower levels on day 8 (p = 0.021). Higher MMP-9 on day 8 was associated with persistent venous occlusion (odds ratio: 1.20 [per 20 ng/mL], 95% CI: 1.02–1.43, p = 0.030). Conclusion We report a novel relationship among MMP-9, parenchymal brain damage, and early venous recanalization, suggesting that circulating MMP-9 is a dynamic marker of brain tissue damage in patients with CVT.

Download Full-text

Leukocyte-derived matrix metalloproteinase-9 mediates blood-brain barrier breakdown and is proinflammatory after transient focal cerebral ischemia

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.01275.2004 ◽

2005 ◽

Vol 289 (2) ◽

pp. H558-H568 ◽

Cited By ~ 282

Author(s):

Jeffrey M. Gidday ◽

Yvan G. Gasche ◽

Jean-C. Copin ◽

Aarti R. Shah ◽

Ronald S. Perez ◽

...

Keyword(s):

Matrix Metalloproteinase ◽

Blood Brain Barrier ◽

Matrix Metalloproteinase 9 ◽

Leukocyte Recruitment ◽

Brain Barrier ◽

Ischemic Brain ◽

Blood Brain ◽

Cellular Source ◽

The Brain ◽

Metalloproteinase 9

Results of recent studies reveal vascular and neuroprotective effects of matrix metalloproteinase-9 (MMP-9) inhibition and MMP-9 gene deletion in experimental stroke. However, the cellular source of MMP-9 produced in the ischemic brain and the mechanistic basis of MMP-9-mediated brain injury require elucidation. In the present study, we used MMP-9−/−mice and chimeric knockouts lacking either MMP-9 in leukocytes or in resident brain cells to test the hypothesis that MMP-9 released from leukocytes recruited to the brain during postischemic reperfusion contributes to this injury phenotype. We also tested the hypothesis that MMP-9 promotes leukocyte recruitment to the ischemic brain and thus is proinflammatory. The extent of blood-brain barrier (BBB) breakdown, the neurological deficit, and the volume of infarction resulting from transient focal stroke were abrogated to a similar extent in MMP-9−/−mice and in chimeras lacking leukocytic MMP-9 but not in chimeras with MMP-9-containing leukocytes. Zymography and Western blot analysis from these chimeras confirmed that the elevated MMP-9 expression in the brain at 24 h of reperfusion is derived largely from leukocytes. MMP-9−/−mice exhibited a reduction in leukocyte-endothelial adherence and a reduction in the number of neutrophils plugging capillaries and infiltrating the ischemic brain during reperfusion; microvessel immunopositivity for collagen IV was also preserved in these animals. These latter results document proinflammatory actions of MMP-9 in the ischemic brain. Overall, our findings implicate leukocytes, most likely neutrophils, as a key cellular source of MMP-9, which, in turn, promotes leukocyte recruitment, causes BBB breakdown secondary to microvascular basal lamina proteolysis, and ultimately contributes to neuronal injury after transient focal stroke.

Download Full-text