Dimethyl fumarate confers neuroprotection by casein kinase 2 phosphorylation of Nrf2 in murine intracerebral hemorrhage.

Edema formation, inflammation and increased blood-brain barrier permeability contribute to poor outcomes after intracerebral hemorrhage (ICH). This study examined the therapeutic effect of dimethyl fumarate (DMF), a fumaric acid ester that activates nuclear factor erythroid-2 related factor 2 (Nrf2) and Nrf2 heterodimerization effector protein musculo-aponeurotic fibrosarcoma-G (MAFG) in a murine ICH model. Male CD-1 mice (n=176) were subjected to intrastriatal infusion of bacterial collagenase (n=126), autologous blood (n=18) or sham surgery (n=32). Four (4) animals not subjected to ICH (naive) were also included in the study. After ICH, animals either received vehicle, dimethyl fumarate (10 mg or 100 mg/kg) or casein kinase 2 inhibitor (E)-3-(2,3,4,5-tetrabromophenyl)acrylic acid (TBCA). Thirty-two mice also received scrambled siRNA or MAFG siRNA 24h before ICH. Brain water content and neurological function were evaluated. Dimethyl fumarate reduced Evans blue dye extravasation, decreased brain water content, and improved neurological deficits at 24 and 72 h after ICH. Casein kinase 2 inhibitor TBCA and MAFG siRNA prevented the effect of dimethyl fumarate on brain edema and neurological function. After ICH, ICAM-1 levels increased and casein kinase 2 levels decreased. Dimethyl fumarate reduced ICAM-1 but enhanced casein kinase 2 levels. Again, casein kinase 2 inhibitor TBCA and MAFG siRNA abolished the effect of dimethyl fumarate on ICAM-1 and casein kinase 2. Dimethyl fumarate preserved pNrf2 and MAFG expression in the nuclear lysate after ICH and the effect of dimethyl fumarate was abolished by casein kinase 2 inhibitor TBCA and MAFG siRNA. Dimethyl fumarate reduced microglia activation in peri-hematoma areas after ICH. The protective effect of dimethyl fumarate on brain edema and neurological function was also observed in a blood injection mouse model. Dimethyl fumarate ameliorated inflammation, reduced blood-brain barrier permeability, and improved neurological outcomes by casein kinase 2 and Nrf2 signaling pathways after experimental ICH in mice.

Iniaghe LO ，Krafft PR ，Klebe DW ，Omogbai EKI ，Zhang JH ，Tang J ... -  《-》

Dimethyl Fumarate Protects Brain From Damage Produced by Intracerebral Hemorrhage by Mechanism Involving Nrf2.

Intracerebral hemorrhage (ICH) represents a devastating form of stroke for which there is no effective treatment. This preclinical study was designed to evaluate dimethyl fumarate (DMF), a substance recently approved for the treatment of multiple sclerosis, as therapy for ICH. We hypothesized that DMF through activating the master regulator of cellular self-defense responses, transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), would act as effective treatment for ICH-mediated damage. Male rats and mice, including Nrf2 knockouts, were subjected to intracerebral injection of blood (to mimic ICH) and then treated with DMF. Neurological deficit, brain edema, gene induction profile and hematoma resolution were evaluated. Phagocytic functions of primary microglia in culture were used to study hematoma resolution. Treatment with DMF induced Nrf2-target genes, improved hematoma resolution, reduced brain edema, and ultimately enhanced neurological recovery in rats and wild-type, but not Nrf2 knockout, mice. Most importantly, the treatment of ICH with DMF showed a 24 h window of therapeutic opportunity. A clinically relevant dose of DMF demonstrates potent therapeutic efficacy and impressive 24 h therapeutic window of opportunity. This study merits further evaluation of this compound as potential treatment for ICH in humans.

Zhao X ，Sun G ，Zhang J ，Ting SM ，Gonzales N ，Aronowski J ... -  《-》

The effect of monascin on hematoma clearance and edema after intracerebral hemorrhage in rats.

Intracerebral hemorrhage (ICH) is a particularly devastating form of stroke with high mortality and morbidity. Hematomas are the primary cause of neurologic deficits associated with ICH. The products of hematoma are recognized as neurotoxins and the main contributors to edema formation and tissue damage after ICH. Finding a means to efficiently promote absorption of hematoma is a novel clinical challenge for ICH. Peroxisome proliferator-activated receptor gamma (PPARγ) and nuclear factor erythroid 2-related factor 2 (Nrf2), had been shown that, can take potential roles in the endogenous hematoma clearance. However, monascin, a novel natural Nrf2 activator with PPARγ agonist, has not been reported to play a role in ICH. This study was designed to evaluate the effect of monascin on neurological deficits, hematoma clearance and edema extinction in a model of ICH in rats. 164 adult male Sprague-Dawley (SD) rats were randomly divided into sham; vehicle; monascin groups with low dosages (1mg/kg/day), middle dosages (5mg/kg/day) and high dosages (10mg/kg/day) respectively. Animals were euthanized at 1, 3 and 7days following neurological evaluation after surgery. We examined the effect of monascin on the brain water contents, blood brain barrier (BBB) permeability and hemoglobin levels, meanwhile reassessed the volume of hematoma and edema around the hematoma by Magnetic Resonance Imaging (MRI) in each group. The high dosage of monascin significantly improved neurological deficits, reduced the volume of hematoma in 1-7days after ICH, decreased BBB permeability and edema formation in 1-3days following ICH. Our study demonstrated that the high dosage of monascin played a neuroprotective role in ICH through reducing BBB permeability, edema and hematoma volume.

Wang J ，Wang G ，Yi J ，Xu Y ，Duan S ，Li T ，Sun XG ，Dong L ... -  《-》

Methylene blue offers neuroprotection after intracerebral hemorrhage in rats through the PI3K/Akt/GSK3β signaling pathway.

Inflammation and apoptosis are two key factors contributing to secondary brain injury after intracerebral hemorrhage (ICH). In the present study, we explored the neuroprotective role of methylene blue (MB) in ICH rats and studied the potential mechanisms involved. Rats were subjected to local injection of collagenase IV in the striatum or sham surgery. We observed that MB treatment could exert a neuroprotective effect on ICH by promoting neurological scores, decreasing the brain water content, alleviating brain-blood barrier disruption, and improving the histological damages in the perihematomal areas. Furthermore, we demonstrated that the various mechanisms underlying MB's neuroprotective effects linked to inhibited apoptosis and inhibited neuroinflammation. In addition, wortmannin, a selective inhibitor of phosphoinositide 3-kinase (PI3K), could reverse the antiapoptotic and anti-inflammatory effects of MB, which suggested that the PI3K-Akt pathway played an important role. In conclusion, these data suggested that MB could inhibit apoptosis and ameliorate neuroinflammation after ICH, and its neuroprotective effects might be exerted via the activation of the PI3K/Akt/GSK3β pathway.

Chen C ，Zhou F ，Zeng L ，Jiang Z ，Hu Z ... -  《-》

Carvacrol alleviates cerebral edema by modulating AQP4 expression after intracerebral hemorrhage in mice.

Carvacrol is a natural compound extracted from many plants of the family Lamiaceae. Previous studies have demonstrated that carvacrol has potential neuroprotective effects in central nervous system diseases such as Alzheimer's disease and cerebral ischemia. In this study, we investigated the preclinical effect of carvacrol on cerebral edema after intracerebral hemorrhage (ICH) using a bacterial collagenase-induced ICH mouse model. Mice were randomly divided into sham (n=43), vehicle-treated (n=51), and carvacrol-treated groups (n=101). In carvacrol-treated group, carvacrol was administrated to mice at 0h, 1h, or 3h after ICH induction. Carvacrol was injected intraperitoneally with single doses of 10, 25, 50, or 100mg/kg. Neurologic dysfunctions, brain water content, aquaporins (AQPs) mRNAs level and AQP4 protein expression in the perihematomal area were evaluated post ICH. Our results showed that carvacrol administration improved neurological deficits after day 3 following ICH (p<0.05). Carvacrol reduced cerebral edema and Evans Blue leakage at day 3 (p<0.05). We also found that carvacrol treatment decreased AQP4 mRNA in a dose-dependent manner at 24h. Furthermore, AQP4 protein expression in the perihematomal area was reduced by carvacrol significantly at day 3 after ICH (p<0.05). Our findings suggest that carvacrol may exert its protective effect on ICH injury by ameliorating AQP4-mediated cerebral edema.

Zhong Z ，Wang B ，Dai M ，Sun Y ，Sun Q ，Yang G ，Bian L ... -  《-》