Preischemic induction of TNF-alpha by physical exercise reduces blood-brain barrier dysfunction in stroke.
This study explores the neuroprotective action of tumor necrosis factor-alpha (TNF-alpha) induced during physical exercise, which, consequently, reduces matrix metalloproteinase-9 (MMP-9) activity and ameliorates blood-brain barrier (BBB) dysfunction in association with extracellular signal-regulated kinase 1 and 2 (ERK1/2) phosphorylation. Adult male Sprague-Dawley rats were subjected to exercise on a treadmill for 3 weeks. A 2-h middle cerebral artery occlusion and reperfusion was administered to exercised and nonexercised animals to induce stroke. Exercised ischemic rats were subjected to TNF-alpha inhibition and ERK1/2 by TNF-alpha antibody or UO126. Nissl staining of coronal sections revealed the infarct volume. Evans blue extravasation and water content evaluated BBB function. Western blot was performed to analyze protein expression of TNF-alpha, ERK1/2, phosphorylated ERK1/2, the basal laminar protein collagen IV, and MMP-9. The activity of MMP-9 was determined by gelatin zymography. Tumor necrosis factor-alpha expression and ERK1/2 phosphorylation were upregulated during exercise. Infarct volume, brain edema, and Evans blue extravasation all significantly decreased in exercised ischemic rats. Collagen IV production increased in exercised rats and remained high after stroke, whereas MMP-9 protein level and activity decreased. These results were negated and returned toward nonexercised values once TNF-alpha or ERK1/2 was blocked. We concluded that preischemic, exercise-induced TNF-alpha markedly decreases BBB dysfunction by using the ERK1/2 pathway.
Guo
Miao
M
Department of Neurosurgery, The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900, USA.
Lin
Victoria
V
Davis
William
W
Huang
Tao
T
Carranza
Aaron
A
Sprague
Shane
S
Reyes
Raul
R
Jimenez
David
D
Ding
Yuchuan
Y
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001812:Blood-Brain Barrier / Q000378:metabolism* / Q000473:pathology; D002070:Butadienes / Q000494:pharmacology; D024141:Collagen Type IV / Q000096:biosynthesis; D003337:Corpus Callosum / Q000378:metabolism* / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D010805:Physical Conditioning, Animal; D051381:Rats; D017207:Rats, Sprague-Dawley; D020521:Stroke / Q000378:metabolism* / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D015854:Up-Regulation / Q000187:drug effects
D000906:Antibodies; D002070:Butadienes; D024141:Collagen Type IV; D004791:Enzyme Inhibitors; D009570:Nitriles; D014409:Tumor Necrosis Factor-alpha; C113580:U 0126; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020780:Matrix Metalloproteinase 9