Intracerebral haemorrhage: mechanisms of injury and therapeutic targets

The Histone Deacetylase Inhibitor Suberoylanilide Hydroxamic Acid (SAHA) Confers Acute Neuroprotection After Intracerebral Hemorrhage in Mice

Spontaneous intracerebral hemorrhage (ICH) is a stroke subtype with no effective treatment. Though ICH is known to induce severe neurological damage, the molecular mechanisms of neurological injury after ICH remain largely unclear. Given the emerging role of epigenetic mechanisms in neurodegeneration, the present study evaluated whether suberoylanilide hydroxamic acid (SAHA: vorinostat), a clinically well-tolerated pan-histone deacetylase inhibitor (HDACi), would attenuate neurological injury and improve functional outcomes in a preclinical model of ICH. Mice were administered with SAHA or vehicle after an induction of ICH and acute neuronal death, glial activation, and neurological outcomes were assessed. SAHA-treated mice exhibited less neurodegeneration with concomitant improvement in neurological outcomes than vehicle-treated mice. Furthermore, SAHA downregulated glial activation and the expression of heme oxygenase-1, a stress-inducible enzyme that plays critical roles in neurological damage after ICH. Altogether, the data strongly suggest the role of epigenetic mechanisms in inducing neurological injury after ICH and raise the possible clinical utility of SAHA for therapeutic intervention after ICH.

USP11, Deubiquitinating Enzyme, Associated with Neuronal Apoptosis Following Intracerebral Hemorrhage

Protein ubiquitination is a dynamic two-way process that can be reversed or regulated by deubiquitinating enzymes (DUB). USP11, located on the X chromosome, 6 is a member of USP subclass of the DUB family. Here, we demonstrate that USP11 may be involved in neuronal apoptosis in the processes of intracerebral hemorrhage (ICH). From the results of Western blot, immunohistochemistry, and immunofluorescence, we obtained a significant up-regulation of USP11 in neurons adjacent to the hematoma following ICH. Increasing USP11 level was found to be accompanied by the up-regulation of active caspase-3, Fas receptor (Fas), Fas ligand (FasL), and active caspase-8. Besides, USP11 co-localized well with active caspase-3 in neurons, indicating its potential role in neuronal apoptosis. What is more, knocking down USP11 by RNA-interference in PC12 cells reduced active caspase-3 expression. Thus, USP11 may play a role in promoting the brain secondary damage following ICH.

Role of lipocalin-2 in brain injury after intracerebral hemorrhage

Lipocalin-2 (LCN2) is a siderophore-binding protein involved in cellular iron transport and neuroinflammation. Both iron and inflammation are involved in brain injury after intracerebral hemorrhage (ICH) and this study examined the role of LCN2 in such injury. Male adult C57BL/6 wild-type (WT) or LCN2-deficient (LCN2(-/-)) mice had an intracerebral injection of autologous blood or FeCl2. Control animals had a sham operation or saline injection. T2-weighted magnetic resonance imaging and behavioral tests were performed at days 1, 3, 7, 14, and 28 after injection. In WT mice, brain LCN2 levels were increased in the ipsilateral basal ganglia after ICH or iron injection. Lipocalin-2-positive cells were astrocytes, microglia, neurons, and endothelial cells. Intracerebral hemorrhage resulted in a significant increase in ferritin expression in the ipsilateral basal ganglia. Compared with WT mice, ICH caused less ferritin upregulation, microglia activation, brain swelling, brain atrophy, and neurologic deficits in LCN2(-/-) mice (P<0.05). The size of the lesion induced by FeCl2 injection as well as the degree of brain swelling and blood-brain barrier disruption were also less in LCN2(-/-) mice (P<0.05). These results suggest a role of LCN2 in enhancing brain injury and iron toxicity after ICH.

Haemorrhage and hemicraniectomy: refining surgery for stroke

PURPOSE OF REVIEW

Intracerebral haemorrhage is a devastating cerebrovascular disease with no established treatment. Its course is often complicated by secondary haematoma expansion and perihemorrhagic oedema. Decompressive hemicraniectomy is effective in the treatment of space-occupying hemispheric ischaemic stroke. The purpose of this review is to assess the role of decompressive hemicraniectomy in intracerebral haemorrhage.

RECENT FINDINGS

After few small previous studies had suggested advantages by the combination of decompressive hemicraniectomy with haematoma removal, decompression on its own has been investigated within the last 5 years. Two case series and one case-control study in altogether 40 patients with severe spontaneous intracerebral haemorrhage have shown mortality rates ranging from 13 to 25% and favourable outcome from 40 to 65%.

SUMMARY

Decompressive hemicraniectomy appears to be a feasible and relatively well tolerated individual treatment option for selected patients with spontaneous intracerebral haemorrhage. Data are insufficient to judge potential benefits in outcome. A randomized trial is justified and mandatory.

Association between two promoter polymorphisms (rs1893219 and rs1893220) of MC2R gene and intracerebral hemorrhage in Korean population

The hypothalamic-pituitary-adrenal (HPA) axis has an important role in the pathogenesis of stroke. We investigated whether single nucleotide polymorphisms (SNPs) of melanocortin 2 receptor (MC2R), also known as adrenocorticotropic hormone (ACTH) receptor, were associated with the development of intracerebral hemorrhage (ICH) in Korean population. Two promoter SNPs [rs1893219 (-853A/G) and rs1893220 (-759G/T)] were genotyped in 145 ICH patients and 331 control subjects using direct sequencing. Multiple logistic regression models were used to determine odds ratios, 95% confidence intervals, and p-values. Two SNPs were associated with the development of ICH (rs1893219, p=0.003 in log-additive model, p=0.023 in dominant model, p=0.002 in recessive model; rs1893220, p=0.005 in log-additive model, p=0.021 in dominant model, p=0.003 in recessive model). The frequencies of the G allele of rs1893219 and the T allele of rs1893220 were decreased in ICH group compared to control group (p=0.003 and p=0.004, respectively). The frequencies of the AG and GT haplotypes comprised of rs1893219 and rs1893220 were also significantly different between the ICH and control groups (p=0.0026 and p=0.0034, respectively). These data suggest that the MC2R gene may contribute to the development of ICH.

Intracerebral Hematoma Contributes to Hydrocephalus After Intraventricular Hemorrhage via Aggravating Iron Accumulation

BACKGROUND AND PURPOSE

The intraventricular hemorrhage (IVH) secondary to intracerebral hemorrhage (ICH) was reported to be relevant to a higher incidence of hydrocephalus, which would result in poorer outcomes for patients with ICH. However, the mechanisms responsible for this relationship remain poorly characterized. Thus, this study was designed to further explore the development and progression of hydrocephalus after secondary IVH.

METHODS

Autologous blood injection model was induced to mimic ICH with ventricular extension (ICH/IVH) or primary IVH in Sprague-Dawley rats. Magnetic resonance imaging, Morris water maze, brain water content, Evans blue extravasation, immunohistochemistry staining, Western blot, iron determination, and electron microscopy were used in these rats. Then, deferoxamine treatment was used to clarify the involvement of iron in the development of hydrocephalus.

RESULTS

Despite the injection of equivalent blood volumes, ICH/IVH resulted in more significant ventricular dilation, ependymal cilia damage, and iron overload, as well as more severe early brain injury and neurological deficits compared with IVH alone. Systemic deferoxamine treatment more effectively reduced ventricular enlargement in ICH/IVH compared with primary IVH.

CONCLUSIONS

Our results show that ICH/IVH caused more significant chronic hydrocephalus and iron accumulation than primary IVH alone. Intracerebral hematoma plays a vital role in persistent iron overload and aggravated hydrocephalus after ICH/IVH.

Effect of therapeutic ultrasound on brain angiogenesis following intracerebral hemorrhage in rats

Intracerebral hemorrhage (ICH) can produce severe neurological deficits in stroke survivors. However, few effective approaches are available to improve the recovery from ICH. Given that therapeutic ultrasound exposure can enhance on angiogenesis in peripheral tissues, the present study was designed to examine the effects of therapeutic ultrasound exposure on the brain angiogenesis following ICH. To this end, we applied once daily therapeutic ultrasound treatment to rats for 7 consecutive days after intracranial infusion of vehicle (Sham control) or collagenase (ICH). Repeated exposure to the low intensity of therapeutic ultrasound decreased behavioral scores in ICH rats, but not in sham control rats. Such an effect was correlated with an increased number of vessel-like structures and microvessels and PCNA positive cells in vWF-positive blood vessels in perihematomal brain tissues at post-ICH day 7. Furthermore, immunohistochemistry and western blotting results showed that ICH trigged the expression of extracellular matrix (ECM)-related molecules, including collagen Is, III, and IV, as well as integrins αvβ3 and α5β1, and exposure to therapeutic ultrasound increased the expression of these molecules. Therefore, our results indicated that repeated exposure to a low intensity of therapeutic ultrasound can increase the expression of collagen and integrins of ECM-related molecules, promote the formation of a large number of vessel-like structure and capillaries around the hematoma, and accelerate the recovery of neurological function impaired by ICH.

Activation of Dopamine D2 Receptor Suppresses Neuroinflammation Through αB-Crystalline by Inhibition of NF-κB Nuclear Translocation in Experimental ICH Mice Model

BACKGROUND AND PURPOSE

Inflammatory injury plays a critical role in intracerebral hemorrhage (ICH)-induced secondary brain injury. Recently, dopamine D2 receptor (DRD2) is identified as an important component controlling innate immunity and inflammatory response in central nervous system, and αB-crystallin (CRYAB) is a potent negative regulator on inflammatory pathways. Here, we sought to investigate the role of DRD2 on neuroinflammation after experimental ICH and the potential mechanism mediated by CRYAB.

METHODS

Two hundred and twenty-four (224) male CD-1 mice were subjected to intrastriatal infusion of bacterial collagenase or autologous blood. Two DRD2 agonists quinpirole and ropinirole were administrated by daily intraperitoneal injection starting at 1 hour after ICH. DRD2 and CRYAB in vivo knockdown was performed 48 hours before ICH insult. Behavioral deficits and brain water content, Western blots, immunofluorescence staining, coimmunoprecipitation (Co-IP) assay, and proteome cytokine array were evaluated.

RESULTS

Endogenous DRD2 and CRYAB expressions were increased after ICH. DRD2 knockdown aggravated the neurobehavioral deficits and the pronounced cytokine expressions. DRD2 activation by quinpirole and ropinirole ameliorated neurological outcome, brain edema, interleukin-1β, and monocyte chemoattractant protein-1 expression, as well as microglia/macrophages activation, in the perihematomal region. These effects were abolished by pretreatment with CRYAB siRNAs. Quinpirole enhanced cytoplasmic binding activity between CRYAB and NF-κB and decreased nuclear NF-κB expression. Similar therapeutic benefits were observed using autologous blood injection model and intranasal delivery of quinpirole.

CONCLUSIONS

DRD2 may have anti-inflammatory effects after ICH. DRD2 agonists inhibited neuroinflammation and attenuated brain injury after ICH, which is probably mediated by CRYAB and enhanced cytoplasmic binding activity with NF-κB.

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

BACKGROUND AND PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Male-Specific Alleviation of Iron-Induced Striatal Injury by Inhibition of Autophagy

Men exhibit a worse survival rate than premenopausal women after intracerebral hemorrhage (ICH), however, no sex-specific management has been concerned. In a rat model involving infusion of ferrous citrate (FC) that simulates iron accumulation after hemorrhage, a higher degree of autophagy associated with higher injury severity was observed in striatum of males than in females. Since the imbalance between the levels of autophagy and energy demand may lead to cell death, we proposed that FC-induced autophagy is detrimental in a male specific manner and autophagy modulation affects injury severity in a sex-dependent manner. Rapamycin, an autophagy inducer, and conditional knockout gene of autophagy-related protein 7 (Atg7) in dopamine receptor D2 (DRD2) neurons were used to test our hypothesis using a mouse model with striatal FC infusion. The result showed that the levels of autophagic cell death and injury severity were higher in male than in female mice. Pre-treatment of FC-infused females with rapamycin increased the FC-induced behavioral deficit and DRD2 neuron death. However, DRD2 neuron-specific knockout of Atg7 decreased FC-induced injury severity and the number of TUNEL(+) DRD2 neurons in males. These results suggest that autophagy in FC-infusion males is overactive with maladaptive consequences and inhibition of autophagy decreases the severity of FC-induced striatal injury in males. These findings present prospects for male-specific therapeutic strategy that targets autophagy in patients suffering from iron overload.

Increased Expression of Mitochondrial Inner-Membrane Protein Mpv17 After Intracerebral Hemorrhage in Adult Rats

The Mpv17 gene encodes a mitochondrial inner-membrane protein that has been implicated in several cell activities. Almost all studies have previously indicated that loss of function or gene-inactivated in Mpv17 can induce the development of disease. Here, we explored the roles of Mpv17 protein in the pathophysiology of intracerebral hemorrhage (ICH). An ICH rat model was established and assessed by behavioral tests. Using western blot and immunohistochemistry, significant up-regulation of Mpv17 was found in neurons in brain areas surrounding the hematoma following ICH. The increase of Mpv17 expression was found to be accompanied by the enhanced expression of p53, Bax, cytochrome c (Cyt c) and active caspase-3, and decreased expression of Bcl-2 in the pathological process of rat ICH. Furthermore, immunofluorescent staining revealed that Mpv17 co-localized with p53, Bax and active caspase-3 in neurons, suggesting its biological function in the process of neuronal apoptosis. Our in vitro study, using Mpv17 RNA interference in primary cortical neurons, indicated that Mpv17 might exert its anti-apoptotic function in neuronal apoptosis. Thus, Mpv17 may play a role in protecting the brain from secondary damage following ICH.

Transplantation of Induced Pluripotent Stem Cells Alleviates Cerebral Inflammation and Neural Damage in Hemorrhagic Stroke

BACKGROUND

Little is known about the effects of induced pluripotent stem cell (iPSC) treatment on acute cerebral inflammation and injuries after intracerebral hemorrhage (ICH), though they have shown promising therapeutic potentials in ischemic stoke.

METHODS

An ICH model was established by stereotactic injection of collagenase VII into the left striatum of male Sprague-Dawley (SD) rats. Six hours later, ICH rats were randomly divided into two groups and received intracerebrally 10 μl of PBS with or without 1 × 10(6) of iPSCs. Subsequently, neural function of all ICH rats was assessed at days 1, 3, 7, 14, 28 and 42 after ICH. Inflammatory cells, cytokines and neural apoptosis in the rats' perihematomal regions, and brain water content were determined on day 2 or 3 post ICH. iPSC differentiation was determined on day 28 post ICH. Nissl(+) cells and glial fibrillary acidic protein (GFAP)(+) cells in the perihematoma and the survival rates of rats in two groups were determined on post-ICH day 42.

RESULTS

Compared with control animals, iPSCs treatment not only improved neurological function and survival rate, but also resulted in fewer intracephalic infiltrations of neutrophils and microglia, along with decreased interleukin (IL)-1β, IL-6 and tumour necrosis factor-alpha (TNF-α), and increased IL-10 in the perihematomal tissues of ICH rats. Furthermore, brain oedema formation, apoptosis, injured neurons and glial scar formation were decreased in iPSCs-transplanted rats.

CONCLUSIONS

Our findings indicate that iPSCs transplantation attenuate cerebral inflammatory reactions and neural injuries after ICH, and suggests that multiple mechanisms including inflammation modulation, neuroprotection and functional recovery might be involved simultaneously in the therapeutic benefit of iPSC treatment against hemorrhagic stroke.

The Effect of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells in a Collagenase-Induced Intracerebral Hemorrhage Rat Model

Intracerebral hemorrhage (ICH) is one of the devastating types of stroke. Human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) have potential benefits in recovery from brain damage following ICH. This study aimed to identify the beneficial effects of hUCB-MSCs and investigate whether they have anti-inflammatory effects on the ICH brain via neurotrophic factors or cytokines. hUCB-MSCs were transplanted into a collagenase-induced ICH rat model. At 2, 9, 16, and 30 days after ICH, rotarod and limb placement tests were performed to measure behavioral outcomes. ICH rats were sacrificed to evaluate the volume of lesion using H&E staining. Immunostaining was performed to investigate neurogenesis, angiogenesis, and anti-apoptosis at 4 weeks after transplantation. Inflammatory factors (TNF-α, COX-2, microglia, and neutrophils) were analyzed by immunofluorescence staining, RT-PCR, and Western blot at 3 days after transplantation. hUCB-MSCs were associated with neurological benefits and reduction in lesion volume. The hUCB-MSCs-treated group tended to reveal high levels of neurogenesis, angiogenesis, and anti-apoptosis (significant for angiogenesis). The expression levels of inflammatory factors tended to be reduced in the hUCB-MSCs-treated group compared with the controls. Our study suggests that hUCB-MSCs may improve neurological outcomes and modulate inflammation-associated immune cells and cytokines in ICH-induced inflammatory responses.

Serum hepcidin concentrations correlate with serum iron level and outcome in patients with intracerebral hemorrhage

Iron plays a detrimental role in the intracerebral hemorrhage (ICH)-induced brain damage, while hepcidin is the most important iron-regulated hormone. Here, we investigate the association between serum hepcidin and serum iron, outcome in patients with ICH. Serum samples of 81 cases with ICH were obtained on consecutive days to detect the levels of hepcidin, iron, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). The National Institutes of Health Stroke Scale score (NIHSS) was measured at admission and on days 7 and 30, and the modified Rankin Scale (mRS) score was evaluated at 3 months after ICH. Additionally, the correlations of serum hepcidin with serum iron and the mRS score were analyzed by a generalized linear model. Higher serum hepcidin levels were detected in patients with poor outcomes (P < 0.001), and the mRS score increased by a mean of 1.135 points (95% CI 1.021-1.247, P < 0.001) for every serum hepcidin quartile after adjusting for other prognostic variables. Pearson correlation analysis showed that serum hepcidin was negatively correlated with serum iron (r = -0.5301, P < 0.001), and a significantly lower concentration of serum iron was found in patients with poor outcomes (P = 0.007). Additionally, serum hepcidin was independently correlated with mRS scores of ICH patients (OR 1.115, 95% CI 0.995-1.249, P = 0.021). Our results suggest that serum hepcidin is closely related to the outcome of patients with ICH and may be a biological marker for outcome prediction.

Impaired adult hippocampal neurogenesis and cognitive ability in a mouse model of intrastriatal hemorrhage

Thrombin released by hematoma is an important mediator of the secondary injury of intracerebral hemorrhage (ICH), however, the effect of thrombin on adult neurogenesis and cognitive ability remains elusive. In this study, intrastriatal injection of 0.05 U thrombin didn't affect the neurogenesis at the subgranular zone (SGZ), which was distal to the injection site. 0.1 U thrombin increased the 5-bromo-2-deoxyuridine(+) (BrdU(+), S-phase proliferating cells)/doublecortin(+) (DCX(+), immature neurons) double labelled neurons, but decreased BrdU(+)/NeuN(+) double labelled mature neurons. Higher doses of thrombin (1 U, 2 U, and 5 U) significantly decreased the BrdU(+)/DCX(+) and BrdU(+)/NeuN(+) double labelled cells. After 1 U thrombin injection, cell apoptosis was found at the dentate gyrus of hippocampus at 3-24 h, but not 5 d post-injury. Thrombin infusion (1 U) induced spatial memory deficits in Morris water maze test; whereas, hirudin, the thrombin antagonist, significantly reversed both neurogenesis loss and spatial learning and memory impairment. In conclusion, at least at short term (5 days) after striatum ICH, the effect of high dose of thrombin on neurogenesis of SGZ, and the spatial learning and memory ability, is detrimental.

Detection of cerebral hemorrhage in rabbits by time-difference magnetic inductive phase shift spectroscopy

Cerebral hemorrhage, a difficult issue in clinical practice, is often detected and studied with computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). However, these expensive devices are not readily available in economically underdeveloped regions, and hence are unable to provide bedside and emergency on-site monitoring. The magnetic inductive phase shift (MIPS) is an emerging technology that may become a new tool to detect cerebral hemorrhage and to serve as an inexpensive partial substitute to medical imaging. In order to study a wider band of cerebral hemorrhage MIPS and to provide more useful information for measuring cerebral hemorrhage, we established a cerebral hemorrhage magnetic induction phase shift spectroscopy (MIPSS) detection system. Thirteen rabbits with five cerebral hemorrhage states were studied using a single coil-coil within a 1 MHz-200 MHz frequency range in linear sweep. A feature band (FB) with the highest detection sensitivity and the greatest stability was selected for further analysis and processing. In addition, a maximum conductivity cerebrospinal fluid (CSF) MRI was performed to verify and interpret the MIPSS result. The average phase shift change induced by a 3 ml injection of autologous blood under FB was -7.7503° ± 1.4204°, which was considerably larger than our previous work. Data analysis with a non-parametric statistical Friedman M test showed that in the FB, MIPSS could distinguish the five states of cerebral hemorrhage in rabbits, with a statistical significance of p<0.05. A B-F distribution profile was designed according to the MIPSS under FB that can provide instantaneous diagnostic information about the cerebral hemorrhage severity from a single set of measurements. The results illustrate that the MIPSS detection method is able to provide a new possibility for real-time monitoring and diagnosis of the severity of cerebral hemorrhage.

A new method to image heme-Fe, total Fe, and aggregated protein levels after intracerebral hemorrhage

An intracerebral hemorrhage (ICH) is a devastating stroke that results in high mortality and significant disability in survivors. Unfortunately, the underlying mechanisms of this injury are not yet fully understood. After the primary (mechanical) trauma, secondary degenerative events contribute to ongoing cell death in the peri-hematoma region. Oxidative stress is thought to be a key reason for this delayed injury, which is likely due to free-Fe-catalyzed free radical reactions. Unfortunately, this is difficult to prove with conventional biochemical assays that fail to differentiate between alterations that occur within the hematoma and peri-hematoma zone. This is a critical limitation, as the hematoma contains tissue severely damaged by the initial hemorrhage and is unsalvageable, whereas the peri-hematoma region is less damaged but at risk from secondary degenerative events. Such events include oxidative stress mediated by free Fe presumed to originate from hemoglobin breakdown. Therefore, minimizing the damage caused by oxidative stress following hemoglobin breakdown and Fe release is a major therapeutic target. However, the extent to which free Fe contributes to the pathogenesis of ICH remains unknown. This investigation used a novel imaging approach that employed resonance Raman spectroscopic mapping of hemoglobin, X-ray fluorescence microscopic mapping of total Fe, and Fourier transform infrared spectroscopic imaging of aggregated protein following ICH in rats. This multimodal spectroscopic approach was used to accurately define the hematoma/peri-hematoma boundary and quantify the Fe concentration and the relative aggregated protein content, as a marker of oxidative stress, within each region. The results revealed total Fe is substantially increased in the hematoma (0.90 μg cm(-2)), and a subtle but significant increase in Fe that is not in the chemical form of hemoglobin is present within the peri-hematoma zone (0.32 μg cm(-2)) within 1 day of ICH, relative to sham animals (0.22 μg cm(-2)). Levels of aggregated protein were significantly increased within both the hematoma (integrated band area 0.10 AU) and peri-hematoma zone (integrated band area 0.10 AU) relative to sham animals (integrated band area 0.056 AU), but no significant difference in aggregated protein content was observed between the hematoma and peri-hematoma zone. This result suggests that the chemical form of Fe and its ability to generate free radicals is likely to be a more critical predictor of tissue damage than the total Fe content of the tissue. Furthermore, this article describes a novel approach to colocalize nonheme Fe and aggregated protein in the peri-hematoma zone following ICH, a significant methodological advancement for the field.

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

BACKGROUND AND PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Hyperglycemia and Mortality Risk in Patients with Primary Intracerebral Hemorrhage: A Meta-Analysis

Hyperglycemia may be associated with worse functional outcomes in patients with primary intracerebral hemorrhage. We performed a systematic review and meta-analysis to investigate the relationship between hyperglycemia and mortality risk in patients with primary intracerebral hemorrhage. We searched PubMed and Embase databases for studies investigating the association between hyperglycemia and mortality risk in patients with primary intracerebral hemorrhage. We estimated the pooled relative risk (RR) with its 95% confidence interval (95% CI) to assess the impact of hyperglycemia on mortality risk. Seventeen studies with a total of 6527 primary intracerebral hemorrhage patients were included. Meta-analysis of those studies showed that hyperglycemia significantly increased risk of mortality in patients with primary intracerebral hemorrhage (RR = 2.36, 95% CI 1.79-3.12). Subgroup analysis by time of follow-up showed that hyperglycemia significantly increased risk of short-term mortality (RR = 3.97, 95% CI 2.13-7.43) and long-term mortality (RR = 1.53, 95% CI 1.14-2.05). The RR of mortality for per 1-mmol/L increment in glucose level was 1.14 (95% CI 1.06-1.22). In patients with primary intracerebral hemorrhage, hyperglycemia significantly increases risk of both short-term mortality and long-term mortality.

Stem cell-based therapies for intracerebral hemorrhage in animal model: a meta-analysis

Stem cell to be a new intervention for treating intracerebral hemorrhage (ICH) might benefit humans. Therefore, we collected animal studies to find the effect of this innovative treatment. In July 2014, we searched Medline (from 1950), Embase (from 1980), China Biology Medicine disk (from 1978) for studies on stem cells used for treating experimental ICH in animal models that reported neurobehavioral and structural outcome. We evaluated the quality of these studies and used a weighted mean difference random affects model for the meta-analysis. We have collected 30 studies from 650 publications identified through systematic review describing the effects of 5 different type of stem cells on 12 different neurobehavioral scales with 1101 rodents or monkeys. Although there is lack of uniformity of the evaluation methods, these researches showed consistent improvements both in neurobehavioral function and structural outcomes. Besides, the quality of these studies needs to be raised. In conclusion, stem cells hold extensive potential in treating ICH, which should be further evaluated with more evidence-based, high-quality animal studies.

Fingolimod alters inflammatory mediators and vascular permeability in intracerebral hemorrhage

Intracerebral hemorrhage (ICH) leads to high rates of death and disability. The pronounced inflammatory reactions that rapidly follow ICH contribute to disease progression. Our recent clinical trial demonstrated that oral administration of an immune modulator fingolimod restrained secondary injury derived from initial hematoma, but the mechanisms remain unknown. In this study, we aim to investigate the effects of fingolimod on inflammatory mediators and vascular permeability in the clinical trial of oral fingolimod for intracerebral hemorrhage (ICH). The results showed that fingolimod decreased the numbers of circulating CD4(+) T, CD8(+) T, CD19(+) B, NK, and NKT cells and they recovered quickly after the drug was stopped. The plasma ICAM level was decreased and IL-10 was increased by fingolimod. Interestingly, fingolimod protected vascular permeability as indicated by a decreased plasma level of MMP9 and the reduced rT1%. In conclusion, modulation of systemic inflammation by fingolimod demonstrates that it is an effective therapeutic agent for ICH. Fingolimod may prevent perihematomal edema enlargement by protecting vascular permeability.

Bone marrow mesenchymal stem cells ameliorate neurological deficits and blood-brain barrier dysfunction after intracerebral hemorrhage in spontaneously hypertensive rats

Spontaneous intracerebral hemorrhage (ICH) is a common and fatal subtype of stroke, with hypertension the most common cause of this disorder. Bone marrow derived mesenchymal stem cells (BM-MSCs) have been shown to elicit protective properties in stroke models. In the present study, male spontaneously hypertensive rats (SHR) were subjected to ICH by intracerebral injection with autologous blood, Wistar-Kyoto (WKY) rats were employed as control. The neurological function outcomes and blood-brain barrier (BBB) were assessed after BM-MSCs transplantation. Our results showed that BM-MSCs grafts via the tail vein significantly decreased the modified neurological severity score (mNSS) and the modified limb placing test (MLPT) score at 14 days after ICH, and the scores were gradually lowered till the end of test. Furthermore, BM-MSCs transplantation effectively attenuated the BBB permeability compared with the vehicle only group, as evidenced by the low level of Evans blue leakage in the BM-MSC group. In addition, we found that BM-MSCs grafts elevated the levels of tight junction associated protein occludin, and type IV collagen. Taken together, our results suggest that intravenously transplanted BM-MSCs exert therapeutic effects on ICH in spontaneously hypertensive rats. The underlying mechanisms are associated with the enhanced neurological function recovery and increased integrity of BBB. Our results provide the increased understanding of the underlying mechanisms and perspective of BMSCs in treatment for stroke.

Toxic role of prostaglandin E2 receptor EP1 after intracerebral hemorrhage in mice

Inflammatory mechanisms mediated by prostaglandins may contribute to the progression of intracerebral hemorrhage (ICH)-induced brain injury, but they are not fully understood. In this study, we examined the effect of prostaglandin E2 receptor EP1 (EP1R) activation and inhibition on brain injury in mouse models of ICH and investigated the underlying mechanism of action. ICH was induced by injecting collagenase, autologous blood, or thrombin into the striatum of middle-aged male and female mice and aged male mice. Effects of selective EP1R agonist ONO-DI-004, antagonist SC51089, and nonspecific Src family kinase inhibitor PP2 were evaluated by a combination of histologic, magnetic resonance imaging (MRI), immunofluorescence, molecular, cellular, and behavioral assessments. EP1R was expressed primarily in neurons and axons but not in astrocytes or microglia after ICH induced by collagenase. In middle-aged male mice subjected to collagenase-induced ICH, EP1R inhibition mitigated brain injury, brain edema, cell death, neuronal degeneration, neuroinflammation, and neurobehavioral deficits, whereas its activation exacerbated these outcomes. EP1R inhibition also was protective in middle-aged female mice and aged male mice after collagenase-induced ICH and in middle-aged male mice after blood- or thrombin-induced ICH. EP1R inhibition also reduced oxidative stress, white matter injury, and brain atrophy and improved functional outcomes. Histologic results were confirmed by MRI. Src kinase phosphorylation and matrix metalloproteinase-9 activity were increased by EP1R activation and decreased by EP1R inhibition. EP1R regulated matrix metalloproteinase-9 activity through Src kinase signaling, which mediated EP1R toxicity after collagenase-induced ICH. We conclude that prostaglandin E2 EP1R activation plays a toxic role after ICH through mechanisms that involve the Src kinases and the matrix metalloproteinase-9 signaling pathway. EP1R inhibition could be a novel therapeutic strategy to improve outcomes after ICH.

Lipocalin-2 in Stroke

Stroke is a leading cause of adult disability in the United States. However, limited number of molecularly targeted therapy exists for stroke. Recent studies have shown that Li-pocalin-2 (LCN2) is an acute phase protein mediating neuroinflammation after ischemic and hemorrhagic strokes. This review is an attempt to summarize some LCN2-related research findings and discuss its role in stroke.

Intercellular cross-talk in intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a devastating cerebrovascular disorder with high mortality and morbidity. Currently, there are few treatment strategies for ICH-induced brain injury. A recent increase in interest in the pathophysiology of ICH has led to elucidation of the pathways underlying ICH-induced brain injury, pathways where intercellular and hematoma to cell signaling play important roles. In this review, we summarize recent advances in ICH research focusing on intercellular and hematoma:cell cross-talk related to brain injury and recovery after ICH. This article is part of a Special Issue entitled SI: Cell Interactions In Stroke.

The role of the microglia in acute CNS injury

Microglia are considered the brain's resident immune cell involved in immune defense, immunocompetence, and phagocytosis. They maintain tissue homeostasis within the brain and spinal cord under normal condition and serves as its initial host defense system. However, when the central nervous system (CNS) faces injury, microglia respond through signaling molecules expressed or released by neighboring cells. Microglial responses are dual in nature. They induce a nonspecific immune response that may exacerbate CNS injury, especially in the acute stages, but are also essential to CNS recovery and repair. The full range of microglial mechanisms have yet to be clarified, but there is accumulating knowledge about microglial activation in acute CNS injury. Microglial responses require hours to days to fully develop, and may present a therapeutic target for intervention with a much longer window of opportunity compare to other neurological treatments. The challenge will be to find ways to selectively suppress the deleterious effects of microglial activation without compromising its beneficial functions. This review aims to provide an overview of the recent progress relating on the deleterious and beneficial effect of microglia in the setting of acute CNS injury and the potential therapeutic intervention against microglial activation to CNS injury.

Up-regulation of Glis2 involves in neuronal apoptosis after intracerebral hemorrhage in adult rats

The novel Krüppel-like zinc finger protein Gli-similar 2 (Glis2), one member of the transcription factors, is involved in controlling the flow of genetic information and the modulation of diverse cellular activities. Accumulating evidence has demonstrated its important roles in adult development and several diseases. However, information regarding the regulation and possible function of Glis2 in the central nervous system is still limited. In this study, we explored the roles of Glis2 during the pathophysiological process of intracerebral hemorrhage (ICH). An ICH rat model was established and assessed by behavioral tests. Expression of Glis2 was significantly up-regulated in brain areas surrounding the hematoma following ICH. Immunofluorescence showed that Glis2 was strikingly increased in neurons, but not astrocytes or microglia. Up-regulation of Glis2 was found to be accompanied by the increased expression of active caspase-3 and Bax and decreased expression of Bcl-2 in vivo and vitro studies. Moreover, knocking down Glis2 by RNA-interference in PC12 cells reduced active caspase-3 and Bax expression while increased Bcl-2. Collectively, we speculated that Glis2 might exert pro-apoptotic function in neurons following ICH.

Intracerebral hemorrhage in mouse models: therapeutic interventions and functional recovery

There has been strong pre-clinical research on mechanisms of initial cell death and tissue injury in intracerebral hemorrhage (ICH). This data has led to the evaluation of several therapeutics for neuroprotection or the mitigation of early tissue damage. Most of these studies have been done in the rat. Also, there has been little study of the mechanisms of tissue repair and recovery. This review examines the testing of candidate therapeutics in mouse models of ICH for their effect on tissue protection and repair. This review will help the readers compare it to the extensively researched rat model of ICH and thus enhance work that are pending in mouse model.

Intranasal delivery of hypoxia-preconditioned bone marrow-derived mesenchymal stem cells enhanced regenerative effects after intracerebral hemorrhagic stroke in mice

Intracerebral hemorrhagic stroke (ICH) causes high mortality and morbidity with very limited treatment options. Cell-based therapy has emerged as a novel approach to replace damaged brain tissues and promote regenerative processes. In this study we tested the hypothesis that intranasally delivered hypoxia-preconditioned BMSCs could reach the brain, promote tissue repair and improve functional recovery after ICH. Hemorrhagic stroke was induced in adult C57/B6 mice by injection of collagenase IV into the striatum. Animals were randomly divided into three groups: sham group, intranasal BMSC treatment group, and vehicle treatment group. BMSCs were pre-treated with hypoxic preconditioning (HP) and pre-labeled with Hoechst before transplantation. Behavior tests, including the mNSS score, rotarod test, adhesive removal test, and locomotor function evaluation were performed at varying days, up to 21days, after ICH to evaluate the therapeutic effects of BMSC transplantation. Western blots and immunohistochemistry were performed to analyze the neurotrophic effects. Intranasally delivered HP-BMSCs were identified in peri-injury regions. NeuN+/BrdU+ co-labeled cells were markedly increased around the hematoma region, and growth factors, including BDNF, GDNF, and VEGF were significantly upregulated in the ICH brain after BMSC treatment. The BMSC treatment group showed significant improvement in behavioral performance compared with the vehicle group. Our data also showed that intranasally delivered HP-BMSCs migrated to peri-injury regions and provided growth factors to increase neurogenesis after ICH. We conclude that intranasal administration of BMSC is an effective treatment for ICH, and that it enhanced neuroregenerative effects and promoted neurological functional recovery after ICH. Overall, the investigation supports the potential therapeutic strategy for BMSC transplantation therapy against hemorrhagic stroke.

Rosiglitazone infusion therapy following minimally invasive surgery for intracerebral hemorrhage evacuation decreases matrix metalloproteinase-9 and blood-brain barrier disruption in rabbits

Background

The objective of this study was to investigate the effects of Rosiglitazone (RSG) infusion therapy following minimally invasive surgery (MIS) for intracerebral hemorrhage(ICH) evacuation on perihematomal secondary brain damage as assessed by MMP-9 levels, blood–brain barrier (BBB) permeability and neurological function.

Methods

A total of 40 male rabbits (2.8–3.4 kg) was randomly assigned to a normal control group (NC group; 10 rabbits), a model control group (MC group; 10 rabbits), a minimally invasive treatment group (MIS group; 10 rabbits) or a combined MIS and RSG group (MIS + RSG group; 10 rabbits). ICH was induced in all the animals, except for the NC group. MIS was performed to evacuate ICH 6 hours after the successful preparation of the ICH model in the MIS and MIS + RSG groups. The animals in the MC group underwent the same procedures for ICH evacuation but without hematoma aspiration, and the NC group was subjected to sham surgical procedures. The neurological deficit scores (Purdy score) and ICH volumes were determined on days 1, 3 and 7. All of the animals were sacrificed on day 7, and the perihematomal brain tissue was removed to determine the levels of PPARγ, MMP-9, BBB permeability and brain water content (BWC).

Results

The Purdy score, perihematomal PPARγ levels, BBB permeability, and BWC were all significantly increased in the MC group compared to the NC group. After performing the MIS for evacuating the ICH, the Purdy score and the ICH volume were decreased on days 1, 3 and 7 compared to the MC group. A remarkable decrease in perihematomal levels of PPARγ, MMP-9, BBB permeability and BWC were observed. The MIS + RSG group displayed a remarkable increase in PPARγ as well as significant decrease in MMP-9, BBB permeability and BWC compared with the MIS group.

Conclusions

RSG infusion therapy following MIS for ICH treatment might be more efficacious for reducing the levels of MMP-9 and secondary brain damage than MIS therapy alone.

Deferoxamine reduces intracerebral hemorrhage-induced white matter damage in aged rats

Iron contributes to c-Jun N-terminal kinases (JNK) activation in young rats and white matter injury in piglets after intracerebral hemorrhage (ICH). In the present study, we examined the effect of deferoxamine on ICH-induced white matter injury and JNK activation and in aged rats. Male Fischer 344 rats (18months old) had either an intracaudate injection of 100μl of autologous blood or a needle insertion (sham). The rats were treated with deferoxamine or vehicle with different regimen (dosage, duration and time window). White matter injury and activation of JNK were examined. We found that a dose of DFX should be at more than 10mg/kg for a therapeutic duration more than 2days with a therapeutic time window of 12h to reduce ICH-induced white matter loss at 2months. ICH-induced white matter injury was associated with JNK activation. The protein levels of phosphorylated-JNK (P-JNK) were upregulated at day-1 after ICH and then gradually decreased. P-JNK immunoreactivity was mostly located in white matter bundles. ICH-induced JNK activation was reduced by DFX treatment. This study demonstrated that DFX can reduce ICH-induced JNK activation and white matter damage.

Measurement of perihematomal edema in intracerebral hemorrhage

BACKGROUND AND PURPOSE

Perihematomal edema (PHE) is a marker of secondary injury in intracerebral hemorrhage (ICH). PHE measurement on computed tomography (CT) is challenging, and the principles used to detect PHE have not been described fully. We developed a systematic approach for CT-based measurement of PHE.

METHODS

Two independent raters measured PHE volumes on baseline and 24-hour post-ICH CT scans of 20 primary supratentorial ICH subjects. Boundaries were outlined with an edge-detection tool and adjusted after inspection of the 3 orthogonal planes. PHE was delineated with the additional principle that it should be (a) more hypodense than the corresponding area in the contralateral hemisphere and (b) most hypodense immediately surrounding the hemorrhage. We examined intra- and interrater reliability using intraclass correlation coefficients and Bland-Altman plots for interrater consistency. CT-based PHE was also compared using magnetic resonance imaging-based PHE detection for 18 subjects.

RESULTS

Median PHE volumes were 22.7 cc at baseline and 20.4 cc at 24 hours post-ICH. There were no statistically significant differences in PHE measurements between raters. Interrater and intrarater reliability for PHE were excellent. At baseline and 24 hours, interrater intraclass correlation coefficients were 0.98 (0.96-1.00) and 0.98 (0.97-1.00); intrarater intraclass correlation coefficients were 0.99 (0.99-1.00) and 0.99 (0.98-1.00). Bland-Altman analysis showed the bias for PHE measurements at baseline and 24 hours, -0.5 cc (SD, 5.4) and -3.2 cc (SD, 5.0), was acceptably small. PHE volumes determined by CT and magnetic resonance imaging were similar (23.9±16.9 cc versus 23.9±16.0 cc, R(2) = 0.98, P<0.0001).

CONCLUSIONS

Our method measures PHE with excellent reliability at baseline and 24 hours post-ICH.

Increased frequency of circulating regulatory T cells in patients with acute cerebral hemorrhage

Cerebral hemorrhage (ICH) is a serious stroke subtype, currently lacking effective treatment. Recent research has shown that CD4(+)CD25(+)FOXP3(+) regulatory T cells (Tregs) play a key role in the immune response of ischemic stroke. However, Tregs in human hemorrhagic stroke are poorly investigated. In this study, a total of 90 ICH patients and 60 healthy controls were recruited. The frequency of circulating Tregs, plasma levels of TGF-β and IL-10, and the severity of neural dysfunction in ICH patients were investigated at different time points post ICH. We found that the peripheral frequency of Tregs in ICH patients was significantly increased, accompanied by boosted activated T cells. Importantly, the elevation of circulating Tregs in patients with severe dysfunction was much higher than that in less-severe patients, suggesting that disease severity affects circulating Tregs to exert regulatory function. Furthermore, both TGF-β and IL-10 that are related to the function of Tregs, were also increased in the peripheral blood of ICH patients. Our results demonstrate that Tregs-mediated immune imbalance might affect the development and severity of ICH, and suggest that Tregs may be used as tools and targets of cellular immunotherapy to effectively treat acute hemorrhagic stroke.

Neuroprotective effects of edaravone after intraventricular hemorrhage in rats

Intraventricular hemorrhage (IVH) is a severity factor and treatment target in intracerebral hemorrhage. This study aimed to investigate whether systemic edaravone, a free-radical scavenger, could attenuate the brain injury after IVH in a rat model. Our findings showed that an intraventricular injection of autologous whole blood resulted in acute brain edema, increased malondialdehyde level, and decreased superoxide dismutase enzyme activity. Immediate edaravone treatment after IVH can reduce IVH-induced brain edema and elevated lipid peroxidation. Furthermore, repeated edaravone treatment (immediately, 24 h, and 48 h after IVH) improved the IVH-induced learning and memory damage. These effects suggest that edaravone may be a potential therapeutic agent for IVH, especially those intracerebral hemorrhage patients with ventricular extension.

Iron-induced necrotic brain cell death in rats with different aerobic capacity

Brain iron overload has a key role in brain injury after intracerebral hemorrhage (ICH). Our recent study demonstrated that ICH-induced brain injury was greater in low capacity runner (LCR) than in high capacity runner (HCR) rats. The present study examines whether iron-induced brain injury differs between LCRs and HCRs. Adult male LCR and HCR rats had an intracaudate injection of iron or saline. Rats were euthanized at 2 and at 24 h after T2 magnetic resonance imaging, and the brains were used for immunostaining and Western blotting. LCRs had more hemispheric swelling, T2 lesion volumes, blood-brain barrier disruption, and neuronal death at 24 h after iron injection (p < 0.05). Many propidium iodide (PI)-positive cells, indicative of necrotic cell death, were observed in the ipsilateral basal ganglia of both HCRs and LCRs at 2 h after iron injection. PI fluorescence intensity was higher in LCRs than in HCRs. In addition, membrane attack complex (MAC) expression was increased at 2 h after iron injection and was higher in LCRs than in HCRs. The PI-positive cells co-localized with MAC-positive cells in the ipsilateral basal ganglia. Iron induces more severe necrotic brain cell death, brain swelling, and blood-brain barrier disruption in LCR rats, which may be related with complement activation and MAC formation.

Targeting secondary injury in intracerebral haemorrhage--perihaematomal oedema

Perihaematomal oedema (PHO) is an important pathophysiological marker of secondary injury in intracerebral haemorrhage (ICH). In this Review, we describe a novel method to conceptualize PHO formation within the framework of Starling's principle of movement of fluid across a capillary wall. We consider progression of PHO through three stages, characterized by ionic oedema (stage 1) and progressive vasogenic oedema (stages 2 and 3). In this context, possible modifiers of PHO volume and their value in identifying patients who would benefit from therapies that target secondary injury are discussed; the practicalities of using neuroimaging to measure PHO volume are also considered. We examine whether PHO can be used as a predictor of neurological outcome following ICH, and we provide an overview of emerging therapies. Our discussion emphasizes that PHO has clinical relevance both as a therapeutic target, owing to its augmentation of the mass effect of a haemorrhage, and as a surrogate marker for novel interventions that target secondary injury.

Necrostatin-1 ameliorates intracerebral hemorrhage-induced brain injury in mice through inhibiting RIP1/RIP3 pathway

Necroptosis is a recently discovered programmed necrosis, regulated by receptor interacting protein kinase 1 (RIP1) and RIP3 after death signal stimulation and could be specifically inhibited by necrostatin-1. The aim of this study was to investigate the role of RIP1 and RIP3 signal pathways in a mouse model of collagenase-induced intracerebral hemorrhage (ICH) and assess the effect of necrostatin-1 on brain injury after ICH. We found that RIP1 and RIP3 proteins were abundantly expressed and increased in mice brain after ICH. Necrostatin-1 pretreatment improved neurological function and attenuated brain edema in mice after ICH. Moreover, necrostatin-1 reduced RIP1-RIP3 interaction and propidium iodide (PI) positive cell death, and further inhibited microglia activation and pro-inflammatory mediator genes [tumor necrosis factor-a (TNF-α) and interleukin-1β (IL-1β)] expression after ICH. These findings indicate that RIP1/RIP3-mediated necroptosis is an important mechanism of cell death after ICH. Through inhibiting necroptosis, necrostatin-1 plays a protective role in reducing necrotic cell death after ICH. Necrostatin-1 is a promising therapeutic agent that protects cells from necroptosis and improves functional outcome.

Nerve regeneration and functional recovery by collagen-binding brain-derived neurotrophic factor in an intracerebral hemorrhage model

Brain-derived neurotrophic factor (BDNF) exerts therapeutic effects following intracerebral hemorrhage (ICH). However, it is difficult to maintain sufficient concentrations in the hemorrhage hemisphere. We demonstrated previously that BDNF fused to a collagen-binding domain (CBD) could bind to collagen in the ventricular ependyma and stimulate cell proliferation in the subventricular zone (SVZ). In this study, we verified the therapeutic effects of CBD-BDNF in the rat ICH model induced by bacterial collagenase by injecting CBD-BDNF into the lateral ventricle of ICH rats. The results demonstrated that CBD-BDNF was retained at high levels in the hemorrhage hemisphere, where it promoted neural regeneration and angiogenesis, reduced tissue loss, and improved functional recovery.

The Role of Circulating Tight Junction Proteins in Evaluating Blood Brain Barrier Disruption following Intracranial Hemorrhage

Brain injury after intracranial hemorrhage (ICH) results in significant morbidity and mortality. Blood brain barrier (BBB) disruption is a hallmark of ICH-induced brain injury; however, data mirroring BBB disruption in human ICH are scarce. The aim of this study was to assess the significance of circulating biomarkers in evaluating BBB disruption after ICH. Twenty-two patients with ICH were recruited in this study. Concentrations of the tight junction proteins (TJs) Claudin-5 (CLDN5), Occludin (OCLN), and zonula occludens 1 (ZO-1) and vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) were measured by using enzyme-linked immunosorbent assay in serum and cerebrospinal fluid (CSF) samples obtained from patients with ICH. The white blood cell (WBC) count in blood and CSF, albumin (ALB) levels in the CSF (ALBCSF), and the BBB ratio were significantly higher in the ICH than in controls (p < 0.05). Significantly higher levels of CLDN5, OCLN, ZO-1, MMP-9, and VEGF in CSF were observed in the ICH group; these biomarkers were also positively associated with BBB ratio (p < 0.05). Our data revealed that circulating TJs could be considered the potential biomarkers reflecting the integrity of the BBB in ICH.

Intracranial hemorrhage and novel anticoagulants for atrial fibrillation: what have we learned?

Intracranial hemorrhage (ICH) affects 0.2-0.5 % of atrial fibrillation (AF) patients taking a novel oral anticoagulant (NOAC) each year. About two thirds of ICHs are intracerebral and one quarter subdural. The 30-day case fatality of NOAC-associated ICH was similar to that of warfarin-associated ICH in two trials. Consistent predictors of ICH are increasing age, a history of prior stroke or TIA, and concomitant use of an antiplatelet drug. Compared to warfarin, the NOACs significantly reduce the risk of ICH by half (risk ratio = 0.44; 95 % CI: 0.37 to 0.51). Compared to aspirin, apixaban has a similar risk of ICH (risk ratio = 0.84; 95 % CI, 0.38 to 1.87). Current treatments for NOAC-associated ICH include nonactivated and activated prothrombin complex concentrate, which reverse the anticoagulant effects of the NOACs, but their effects on bleeding and patient outcome are not known. Future treatments for NOAC-associated ICH promise to include specific antidotes to dabigatran (e.g., aDabi-Fab, PER977) and factor Xa inhibitors (e.g., r-Antidote PRT064445, PER977).

Quercetin promotes neuronal and behavioral recovery by suppressing inflammatory response and apoptosis in a rat model of intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a common and devastating disease affecting millions of people worldwide annually. Exaggerated inflammation and apoptosis are two pivotal pathological processes for secondary brain injury after ICH. Quercetin, a flavonoid widely distributed in various herbs, fruits and vegetables, has been proved to improve neuronal functional recovery in spinal cord injury rats. However, the efficacy of quercetin in caring for post-ICH brain injury has not been investigated. In the present study, we established an ICH model by injecting type VII bacterial collagenase (0.5U) into the central striatum of male Sprague-Dawley rats. The animals were randomized to four groups: sham-operation group; ICH + vehicle group; ICH + 5 mg/kg quercetin group; and ICH + 50 mg/kg quercetin group. The expression levels of IL-1β, IL-4, IL-6 and TNF-α in the brain tissue were assayed by Real-time PCR, ELISA and Western Blot, and cell apoptosis was assayed by TUNEL and caspase-3 staining 3 days after model establishment. It was found that the lesion volume, the brain water content, the expression levels of the four inflammation markers and the number of apoptotic cells were reduced significantly in ICH rats receiving quercetin, especially in 50 mg/kg quercetin group. These results confirmed the therapeutic efficacy of quercetin in repairing brain injury, probably by inhibiting inflammatory response and apoptosis, thus promoting nerve functional restoration.

Effect of low voltage AC fields on cardiovascular implants

Coronary Artery Stents have been the preferred form of treatment for vascular occlusive disease, due to the minimally invasive surgical procedure, post-operative recovery time and cost, when compared to open coronary bypass surgery. The cellular response upon applying an AC electric field to type 316LM Stainless Steel stent mimics was investigated in this paper. The highest RBC adhesion was observed at voltages higher than 88 mV and lower than 74 mV. Their unique alignment along the lines of fracture on the stent surface at 88 mV was a phenomenon caused by an increase in electrical conductivity in these regions. Being able to control RBC adhesion may have various clinical implications such as inhibition of thrombus formation, and provide a basis to analyse whether electric fields may be applied to cancer therapy as well.

CX3CR1 signaling on monocytes is dispensable after intracerebral hemorrhage

Intracerebral hemorrhage is a subset of stroke for which there is no specific treatment. The Ly6Chi CCR2+ monocytes have been shown to contribute to acute injury after intracerebral hemorrhage. The other murine monocyte subset expresses CX3CR1 and lower Ly6C levels, and contributes to repair in other disease models. We hypothesized that the Ly6Clo CX3CR1+ monocytes would contribute to recovery after intracerebral hemorrhage. Intracerebral hemorrhage was modeled by blood injection in WT and CX3CR1-null bone marrow chimeras. Neurological outcomes and leukocyte recruitment were quantified at various time points. Functional outcomes were equal at 1, 3, 7, and 14 days after intracerebral hemorrhage in both genotypes. No differences were observed in leukocyte recruitment between genotypes on either 3 or 7 days after intracerebral hemorrhage. A few hundred Ly6Clo monocytes were found in the ipsilateral hemisphere in each genotype and they did not change over time. Peripherally derived CX3CR1+ monocytes were observed in the perihematomal brain 7 and 14 days after intracerebral hemorrhage. Our data suggests CX3CR1 signaling on monocytes does not play an influential role in acute injury or functional recovery after intracerebral hemorrhage and therefore CX3CR1 is not a therapeutic target to improve outcome after intracerebral hemorrhage.

Potential role of blood biomarkers in the management of nontraumatic intracerebral hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH), a subtype of stroke associated with high mortality and disability, accounts for 13% of all strokes. Basic and clinical research has contributed to our understanding of the complex pathophysiology of neuronal injury in ICH. Outcome rates, however, remain stable, and questions regarding acute management of ICH remain unanswered. Newer research is aiming at matching measured levels of serum proteins, enzymes, or cells to different stages of brain damage, suggesting that blood biomarkers may assist in acute diagnosis, therapeutic decisions, and prognostication. This paper provides an overview on the most promising blood biomarkers and their potential role in the diagnosis and management of spontaneous ICH.

SUMMARY

Information was collected from studies, reviews, and guidelines listed in PubMed up to November 2013 on blood biomarkers of nontraumatic ICH in humans. We describe the potential role and limitations of GFAP, S100B/RAGE, and ApoC-III as diagnostic biomarkers, β-​Amyloid as a biomarker for etiological classification, and 27 biomarkers for prognosis of mortality and functional outcome. Within the group of prognostic markers we discuss markers involved in coagulation processes (e.g., D-Dimers), neuroendocrine markers (e.g., copeptin), systemic metabolic markers (e.g., blood glucose levels), markers of inflammation (e.g., IL-6), as well as growth factors (e.g., VEGF), and others (e.g., glutamate). Some of those blood biomarkers are agents of pathologic processes associated with hemorrhagic stroke but also other diseases, whereas others play more distinct pathophysiological roles and help in understanding the basic mechanisms of brain damage and/or recovery in ICH.

KEY MESSAGES

Numerous blood biomarkers are associated with different pathophysiological pathways in ICH, and some of them promise to be useful in the management of ICH, eventually contributing additional information to current tools for diagnosis, therapy monitoring, risk stratification, or intervention. Up to date, however, no blood biomarker of ICH has been studied sufficiently to find its way into clinical routine yet; well-designed, large-scale, clinical studies addressing relevant clinical questions are needed. We suggest that the effectiveness of biomarker research in ICH might be improved by international cooperation and shared resources for large validation studies, such as provided by the consortium on stroke biomarker research (http://stroke-biomarkers.​com/page.php?title=Resources).

CHMP4B, ESCRT-III associating protein, associated with neuronal apoptosis following intracerebral hemorrhage

Charged multivesicular body protein (CHMP) represents a family of small helical proteins that contain an N-terminal basically charged region and a smaller C-terminal acidic region, which are highly conserved in all eukaryotes. CHMP4B, a core component of the endosomal sorting complex required for transport (ESCRT)-III, is requisite for endosomal sorting and other biological processes. Here, we demonstrate that CHMP4B may be involved in neuronal apoptosis in the processes of intracerebral hemorrhage (ICH). From the results of Western blot, immunohistochemistry and immunofluorescence, we obtained a significant up-regulation of CHMP4B in neurons adjacent to the hematoma following ICH. Increasing CHMP4B level was found to be accompanied by the up-regulation of Fas receptor (Fas), Fas ligand (FasL), active caspase-8, and active caspase-3. Besides, CHMP4B co-localized well with Fas and active caspase-3 in neurons, indicating its potential role in neuronal apoptosis. What's more, our in vitro study, using CHMP4B RNA interference in PC12 cells, further confirmed that CHMP4B might exert its pro-apoptotic function on neuronal apoptosis through extrinsic pathway. Thus, CHMP4B may play a role in promoting the brain damage following ICH.