Exercise preconditioning mitigates brain injury after cerebral
ischemia-reperfusion in rats by restraining TIMP1
Abstract
Cerebral ischemic disease is the most common cerebrovascular disease,
especially ischemic stroke. Exercise has a protective function on brain
tissues following cerebral ischemia-reperfusion injury (CIRI), but its
preventive effect and mechanism in CIRI remain unclear. This research
aimed to investigate the effect and mechanism of exercise
preconditioning on CIRI. The middle cerebral artery occlusion (MCAO)
operation was prepared to set up CIRI rats. All rats were randomized
into the MCAO, exercise (exercise preconditioning plus MCAO operation),
vector (exercise preconditioning, MCAO operation plus intraventricular
injection of empty vector), and tissue inhibitor of metalloprotease 1
overexpression (OE-TIMP1) groups (exercise preconditioning, MCAO
operation plus intraventricular injection of OE-TIMP1). The results
indicated that exercise preconditioning effectively suppressed the brain
dysfunction and TIMP1 mRNA level in MCAO rats, which was partially
offset by OE-TIMP1. Also, the attenuation of exercise on the neuron
death status and the infarction size in MCAO rats was counteracted by
OE-TIMP1. This study also confirmed that exercise weakened apoptosis and
oxidative stress damage, with a notable increase of Bcl-2, superoxide
dismutase, and glutathione peroxidase production, and an evident
decrease of Bax, caspase 3, and malondialdehyde in MCAO rats, while the
effect was partially reversed after overexpressing TIMP1. Additionally,
the down-regulation of exercise on the protein levels of TIMP1,
hypoxia-inducible factor-alpha, vascular endothelial growth factor
receptor-2, VEGF, and Notch 1 in MCAO rats was partially reversed by
OE-TIMP1. Altogether, exercise preconditioning had protective effects on
CIRI by restraining TIMP1. This study provides new targets and
therapeutic strategies for the prevention of CIRI.