Matrix metalloproteinases inhibition provides neuroprotection against hypoxia-ischemia in the developing brain.
The present study was designed to investigate the role of matrix metalloproteinases (MMPs) in the immature brain and the long term effects of early MMPs inhibition after hypoxic-ischemic (HI) injury. HI was induced by unilateral ligation of the right carotid artery followed by hypoxia (8% O(2) for 2 h) in P7 rat pups. GM6001, a broad spectrum MMPs inhibitor, was injected (50 mg/kg or 100 mg/kg) intraperitoneally at 2 h and 24 h after HI injury. Blood-brain barrier (BBB) integrity, brain edema, MMP-2/-9 activity, TIMP-1/-2 and tight junction protein (TJP) level were evaluated using IgG staining, Evan's blue extravasation, brain water content, zymography and western blot. Doxycycline, another MMPs inhibitor, was injected (10 mg/kg or 30 mg/kg) intraperitoneally at 2 h after HI, then BBB integrity and brain edema were measured at 48 h post-HI using brain water content measurement and IgG staining. The long-term effects of early MMPs inhibition (GM6001, 100 mg/kg) were evaluated by neurobehavioral tests, body weight, and brain atrophy measurement. GM6001 attenuated brain edema and BBB disruption at the dosage of 100 mg/kg. MMP-2 activity increased at 24 h and peaked at 48 h after HI, whereas MMP-9 activity peaked at 24 h and tapered by 48 h after HI. MMP-9/-2 activities were significantly attenuated by GM6001 at 24 h and 48 h after HI. The degradation of TJPs (ZO-1 and occludin) at 48 h after HI was reversed by GM6001 treatment. Early MMPs inhibition had long-term effects that attenuated ipsilateral brain tissue loss, and improved neurobehavioral outcomes after HI. These results suggest that early MMPs inhibition with a broad-spectrum inhibitor provides both acute and long-term neuroprotection in the developing brain by reducing TJPs degradation, preserving BBB integrity, and ameliorating brain edema after neonatal HI injury.
Chen
Wanqiu
W
Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, California, USA.
Hartman
Richard
R
Ayer
Robert
R
Marcantonio
Suzanne
S
Kamper
Joel
J
Tang
Jiping
J
Zhang
John H
JH
D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001284:Atrophy / Q000517:prevention & control; D001812:Blood-Brain Barrier / Q000187:drug effects; D001929:Brain Edema / Q000209:etiology / Q000517:prevention & control; D004151:Dipeptides / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D020925:Hypoxia-Ischemia, Brain / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D018782:Maze Learning / Q000187:drug effects; D008565:Membrane Proteins / Q000378:metabolism; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors*; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D010750:Phosphoproteins / Q000378:metabolism; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000235:genetics / Q000378:metabolism; D062826:Zonula Occludens-1 Protein
D004151:Dipeptides; D008565:Membrane Proteins; C078131:N-(2(R)-2-(hydroxamidocarbonylmethyl)-4-methylpentanoyl)-L-tryptophan methylamide; D018696:Neuroprotective Agents; D010750:Phosphoproteins; D019715:Tissue Inhibitor of Metalloproteinase-1; C569044:Tjp1 protein, rat; D062826:Zonula Occludens-1 Protein; D019716:Tissue Inhibitor of Metalloproteinase-2; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9