Resveratrol Preconditioning Induces a Novel Extended Window of Ischemic Tolerance in the Mouse Brain

Abstract

Background and Purpose Prophylactic treatments that afford neuroprotection against stroke may emerge from the field of preconditioning. Resveratrol mimics ischemic preconditioning, reducing ischemic brain injury when administered two days prior to global ischemia in rats. This protection is linked to Sirt1 and enhanced mitochondrial function possibly through its repression of UCP2. BDNF is another neuroprotective protein associated with Sirt1. In this study we sought to identify the conditions of resveratrol preconditioning (RPC) that most robustly induce neuroprotection against focal ischemia in mice. Methods We tested four different RPC paradigms against a middle cerebral artery occlusion (MCAo) model of stroke. Infarct volume and neurological score were calculated 24 hours following MCAo. Sirt1-chromatin binding was evaluated by ChIP-qPCR. Percoll gradients were used to isolate synaptic fractions and changes in protein expression were determined via Western blot analysis. BDNF concentration was measured using a BDNF-specific ELISA assay. Results While repetitive RPC induced neuroprotection from MCAo, strikingly one application of RPC 14 days prior to MCAo showed the most robust protection, reducing infarct volume by 33% and improving neurological score by 28%. Fourteen days following RPC, Sirt1 protein was increased 1.5 fold and differentially bound to the UCP2 and BDNF promoter regions. Accordingly, synaptic UCP2 protein decreased by 23% and cortical BDNF concentration increased 26%. Conclusions RPC induces a novel extended window of ischemic tolerance in the brain that lasts for at least 14 days. Our data suggest that this tolerance may be mediated by Sirt1, through upregulation of BDNF and downregulation of UCP2.

Neuronal SIRT1 (Silent Information Regulator 2 Homologue 1) Regulates Glycolysis and Mediates Resveratrol-Induced Ischemic Tolerance

“…Resveratrol preconditioning was induced by treatment with trans -resveratrol (3,4’,5-trihydroxy- trans -stilbene, 10 mg/kg (Sigma) in 1.5% DMSO) or vehicle (1.5% DMSO) IP, 2 days prior to tMCAo performed as previously described 12 . Mice were anesthetized with 3% isoflurane in 100% O 2 and maintained at 37.0 °C through a rectal monitoring heating pad (Harvard Apparatus, Holliston, MA).…”

“…Twenty-four hours after tMCAo, animals were scored based on a neurobehavioral battery (body symmetry, gait, climbing, circling behavior, forelimb symmetry, compulsory circling, and whisker response) as previously described 12 . Focal score ranges from 0 – 28, where 0 is considered normal and 28 indicates extremely severe deficits.…”

“…Triphenyl tetrazolium chloride (TTC, Sigma) staining for infarct was performed as previously described 12 . Infarcted area and total ipsilateral area were measured using ImageJ software and infarct was calculated as a percentage of the total ipsilateral hemisphere.…”

“…What’s more, it is postulated that silent information regulator 2 homologue 1 (Sirt1) mediates at least some of these effects 4 . Adding to mechanistic complexity, Sirt1 is expressed in both brain and peripheral tissues and has been implicated in the regulation of inflammation 10 , cerebral blood flow 11 and neuronal functions 12 . It remains to be tested whether Sirt1 is essential for RPC-induced ischemic tolerance and if so, in which cell types.…”

Targeting ONOO^-/HMGB1/MMP-9 Signaling Cascades: Potential for Drug Development from Chinese Medicine to Attenuate Ischemic Brain Injury and Hemorrhagic Transformation Induced by Thrombolytic Treatment

“…Proteomic analysis revealed that resveratrol treatment in a rat MCAO model regulated various proteins related to oxidative stress and energy metabolism [133]. Pretreatment with resveratrol even 14 days before MCAO reduced the brain infarct volume by 33% in rats, which was mediated by silent mating type information regulation 2 homolog 1 (SIRT1) [134]. Nrf2 activation is another mechanism of resveratrol which mediates preconditioning protective effects in a rodent stroke model, possibly through upregulating antioxidant protein expression and maintaining mitochondrial coupling [135,136].…”