title: A bout of treadmill exercise increases matrix metalloproteinase-9 activity in the rat hippocampus.
abstract: Regular exercise induces a variety of structural changes in the hippocampus of rodents, although the underlying mechanisms remain obscure. Particularly, the possible involvement of molecules regulating the remodeling of the extracellular matrix (ECM) is under-studied. Matrix metalloproteinase-9 (MMP-9), an extracellular protease, plays a critical role in regulating neuronal plasticity by remodeling the ECM in the brain. The current study used gel zymography to examine for changes in the proteolytic activity of MMP-9 in the rat hippocampus following a bout of treadmill exercise at mild (10m/min) or moderate (25m/min) intensity. We found that MMP-9 activity was significantly increased at 12h after mild treadmill exercise. However, the activity of MMP-2 and the expression level of the tissue inhibitor of metalloproteinase-1 (TIMP-1) were unchanged following exercise. These findings suggest that exercise triggers MMP-9 activation in the hippocampus, which might be a new molecular mechanism of exercise-induced hippocampal plasticity.
authors.affiliation: Laboratory of Behavioral Physiology, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan. Electronic address: t-nishijima@tmu.ac.jp.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nishijima
authors.affiliation: Laboratory of Behavioral Physiology, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Kawakami
authors.affiliation: Laboratory of Behavioral Physiology, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kita
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D006624:Hippocampus / Q000201:enzymology*; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D010805:Physical Conditioning, Animal; D017208:Rats, Wistar; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism
chemical_list: D019715:Tissue Inhibitor of Metalloproteinase-1; D020778:Matrix Metalloproteinase 2; C522363:Mmp2 protein, rat; D020780:Matrix Metalloproteinase 9; C572337:Mmp9 protein, rat
keywords: Exercise; Extracellular matrix; Gel zymography; Hippocampus; MMP-9