Sulforaphane preconditioning of the Nrf2/HO-1 defense pathway protects the cerebral vasculature against blood–brain barrier disruption and neurological deficits in stroke

• Published in: Free radical biology & medicine Vol. 65; pp. 1012 - 1022
• Main Authors: Alfieri, Alessio, Srivastava, Salil, Siow, Richard C.M, Cash, Diana, Modo, Michel, Duchen, Michael R, Fraser, Paul A, Williams, Steven C.R, Mann, Giovanni E
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-12-2013
• Subjects: Animals; antioxidants; astrocytes; blood-brain barrier; Blood-Brain Barrier - drug effects; Blood-Brain Barrier - metabolism; Blood-Brain Barrier - pathology; brain; Cerebral Arteries - drug effects; Cerebral Arteries - enzymology; death; defense mechanisms; edema; endothelium; Gene Expression; heme oxygenase (biliverdin-producing); Heme Oxygenase-1 - genetics; Heme Oxygenase-1 - metabolism; infarction; Infarction, Middle Cerebral Artery - drug therapy; Infarction, Middle Cerebral Artery - metabolism; Isothiocyanates - pharmacology; Isothiocyanates - therapeutic use; magnetic resonance imaging; Male; Membrane Proteins - genetics; Membrane Proteins - metabolism; Microvessels - enzymology; Neuroprotective Agents - pharmacology; Neuroprotective Agents - therapeutic use; NF-E2-Related Factor 2 - genetics; NF-E2-Related Factor 2 - metabolism; nutritional intervention; Oxidative Stress; protein synthesis; Psychomotor Disorders - metabolism; Psychomotor Disorders - prevention & control; rats; Rats, Sprague-Dawley; Reperfusion Injury - metabolism; Reperfusion Injury - prevention & control; Signal Transduction; stroke; Up-Regulation; MCAo; BBB; HO; Heme oxygenase; 3,3′-diaminobenzidine; peroxiredoxin 1; Iba1; Gliovascular complex; Blood–brain barrier; Nrf2; RNS; Sulforaphane; rat endothelial cell antigen-1; ionized calcium binding adaptor molecule 1; reactive oxygen species; reactive nitrogen species; antioxidant response element; Stroke; DAB; DAPI; RECA-1; Kelch-like ECH associated protein 1; GFAP; ARE; 4,6-diamidino-2-phenylindole; ROS; Keap1; Preconditioning; Prx1; glial fibrillary acidic protein; nuclear factor erythroid 2-related factor 2; middle cerebral artery occlusion
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/j.freeradbiomed.2013.08.190

Disruption of the blood–brain barrier (BBB) and cerebral edema are the major pathogenic mechanisms leading to neurological dysfunction and death after ischemic stroke. The brain protects itself against infarction via activation of endogenous antioxidant defense mechanisms, and we here report the first evidence that sulforaphane-mediated preactivation of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream target heme oxygenase-1 (HO-1) in the cerebral vasculature protects the brain against stroke. To induce ischemic stroke, Sprague-Dawley rats were subjected to 70min middle cerebral artery occlusion (MCAo) followed by 4, 24, or 72h reperfusion. Nrf2 and HO-1 protein expression was upregulated in cerebral microvessels of peri-infarct regions after 4–72h, with HO-1 preferentially associated with perivascular astrocytes rather than the cerebrovascular endothelium. In naïve rats, treatment with sulforaphane increased Nrf2 expression in cerebral microvessels after 24h. Upregulation of Nrf2 by sulforaphane treatment prior to transient MCAo (1h) was associated with increased HO-1 expression in perivascular astrocytes in peri-infarct regions and cerebral endothelium in the infarct core. BBB disruption, lesion progression, as analyzed by MRI, and neurological deficits were reduced by sulforaphane pretreatment. As sulforaphane pretreatment led to a moderate increase in peroxynitrite generation, we suggest that hormetic preconditioning underlies sulforaphane-mediated protection against stroke. In conclusion, we propose that pharmacological or dietary interventions aimed to precondition the brain via activation of the Nrf2 defense pathway in the cerebral microvasculature provide a novel therapeutic approach for preventing BBB breakdown and neurological dysfunction in stroke.