Intracerebral haemorrhage: mechanisms of injury and therapeutic targets

Intracranial Hypertension After Spontaneous Intracerebral Hemorrhage: A Systematic Review and Meta-analysis of Prevalence and Mortality Rate

The objective of this study was to determine the prevalence of intracranial hypertension (IHT) and the associated mortality rate in patients who suffered from primary intracerebral hemorrhage (ICH). A secondary objective was to assess predisposing factors to IHT development. We conducted a systematic literature search of major electronic databases (MEDLINE, EMBASE, and Cochrane Library), for studies that assessed intracranial pressure (ICP) monitoring in patients with acute ICH. Study level and outcome measures were extracted. The meta-analysis was performed using a random-effects model. A total of six studies comprising 381 patients were pooled to estimate the overall prevalence of any episode of IHT (ICP > 20 mmHg) after ICH. The pooled prevalence rate for any episode of IHT after ICH was 67% (95% CI 51-84%). Four studies comprising 239 patients were pooled in order to estimate the overall mortality rate associated with IHT. Pooled mortality rate was 50% (95% CI 24-76%). For both outcomes, heterogeneity was statistically significant, and risk of bias was nonsignificant. Reported variables correlated significantly with increased ICP were lower Glasgow Coma Scale score at admission, midline shift, hemorrhage volume, and hydrocephalus. The prevalence and mortality rates associated with IHT after ICH are high and may be underestimated. Predicting factors for the development of IHT reflect the magnitude of the primary injury. However, the results of present meta-analysis should be interpreted with caution due to methodological limitations such as selection bias of patients who had ICP monitoring, and lack of standardized IHT definition.

BM-MSC Transplantation Alleviates Intracerebral Hemorrhage-Induced Brain Injury, Promotes Astrocytes Vimentin Expression, and Enhances Astrocytes Antioxidation via the Cx43/Nrf2/HO-1 Axis

Intracerebral hemorrhage (ICH) is a particularly severe form of stroke, and reactive astrogliosis is a common response following injury to the central nervous system (CNS). Mesenchymal stem cells (MSCs) are reported to promote neurogenesis and alleviate the late side effects in injured brain regions. Gap junctions (Gjs) are abundant in the brain, where the richest connexin (Cx) is Cx43, most prominently expressed in astrocytes. Nuclear factor erythroid 2-related factor 2 (Nrf2) is an essential transcription factor regulating antioxidant reactions. Here, we aimed to explore whether bone marrow MSCs (BM-MSCs) could alleviate brain injury and protect astrocytes from apoptosis, by regulating Cx43 and Nrf2. We validated the effect of BM-MSC transplantation in an ICH model in vivo and in vitro and detected changes using immunofluorescence, as well as protein and mRNA expression of glial fibrillary acidic protein (GFAP), vimentin (VIM), Cx43, Nrf2, and heme oxygenase-1 (HO-1). Our results showed that BM-MSC transplantation attenuated brain injury after ICH and upregulated VIM expression in vivo and in vitro. Additionally, Cx43 upregulation and Nrf2 nuclear translocation were observed in astrocytes cocultured with BM-MSC. Knockdown of Cx43 by siRNA restrained Nrf2 nuclear translocation. Cx43 and Nrf2 had a connection as determined by immunofluorescence and coimmunoprecipitation. We demonstrated that astrocytes undergo astroglial-mesenchymal phenotype switching and have anti-apoptotic abilities after BM-MSC transplantation, where Cx43 upregulation triggers Nrf2 nuclear translocation and promotes its phase II enzyme expression. The Cx43/Nrf2 interaction of astrocytes after BM-MSC transplantation may provide an important therapeutic target in the management of ICH.

Lin28 is associated with astrocytic proliferation during intracerebral hemorrhage

As an evolutionarily conserved RNA-binding protein, LIN28 is known to be involved in the regulation of the translation and stability of a large number of mRNAs and the biogenesis of certain miRNAs. Increasing evidence indicates that LIN28 regulates many cellular processes, such as embryonic stem cell proliferation, cell fate succession, developmental timing, and oncogenesis. However, the expression and function of LIN28 after intracerebral hemorrhage (ICH) are still unclear. In this study, we performed an intracranial hemorrhage model in adult rats and western blot, immunohistochemistry, as well as immunofluorescence showed that LIN28 was obviously up-regulation in neurons adjacent to the hematoma after ICH. Besides, the transitory increase of LIN28 expression was paralleled with the up-regulation of proliferating cell nuclear antigen (PCNA) as well as GFAP. Hence, LIN28 might play an important role in astrocyte proliferation after ICH.

Chronic restraint stress exacerbates neurological deficits and disrupts the remodeling of the neurovascular unit in a mouse intracerebral hemorrhage model

Growing evidences have shown that patients recovering from stroke experience high and unremitting stress. Chronic restraint stress (CRS) has been found to exacerbate neurological impairments in an experimental focal cortical ischemia model. However, there have been no studies reporting the effect and mechanism of CRS on intracerebral hemorrhage (ICH). This study aimed to evaluate the effect of CRS on a mouse ICH model. Adult male C57BL mice were subjected to infusion of collagenase IV (to induce ICH) or saline (for sham) into the left striatum. After ICH, animals were stressed with application of CRS protocol for 21 days. Our results showed that CRS significantly exacerbated neurological deficits (Garcia test, corner turn test, and wire grip test) and the ipsilateral brain atrophy and reduced body weight gain after ICH. Immunofluorescence staining indicated that CRS exerted significant suppressive effects on neuron, astrocyte, vascular endothelial cell and pericyte and excessively activated microglia post ICH. All of the key cellular components mentioned above are involved in the neurovascular unit (NVU) remodeling in the peri-hemorrhagic region after ICH. Western blot results showed that matrix metalloproteinase (MMP)-9 and tight junction (TJ) proteins including zonula occludens-1, occludin and claudin-5 were increased after ICH, but MMP-9 protein was further up-regulated and TJ-related proteins were down-regulated by CRS. In addition, ICH-induced activation of endoplasmic reticulum stress and apoptosis were further strengthened by CRS. Collectively, CRS exacerbates neurological deficits and disrupts the remodeling of the peri-hemorrhagic NVU after ICH, which may be associated with TJ proteins degradation and excessive activation of MMP-9 and endoplasmic reticulum stress-apoptosis.LAY SUMMARYCRS exacerbates neurological deficits and disrupts the remodeling of the NVU in the recovery stage after ICH, which suggest that monitoring chronic stress levels in patients recovering from ICH may merit consideration in the future.

Remote Ischemic Conditioning for Intracerebral Hemorrhage (RICH-1): Rationale and Study Protocol for a Pilot Open-Label Randomized Controlled Trial

Background and rationale: Although many therapies have been investigated for intracerebral hemorrhage (ICH), none have succeeded in improving the functional outcomes. Remote ischemic conditioning (RIC) has been proven to promote hematoma resolution and improve neurological outcomes in an ICH model; whether it is safe and feasible in patients with ICH remains unknown. This trial aims to assess the safety, feasibility, and preliminary efficacy of RIC in patients with ICH and to plan for a phase-2 study. Methods: A proof-of-concept, assessor-blinded, pilot open-label randomized controlled trial will be carried out with patients with ICH within 24-48 h of ictus. All participants will be randomly allocated to the intervention group and the control group with a 1:1 ratio (n = 20) and will be treated with standard managements according to the guidelines. Participants allocated to the intervention group will receive RIC once daily for 7 consecutive days. Cranial computed tomography examinations will be performed at baseline, and on days 3, 7, and 14. Neurological outcomes will be assessed at baseline, and on days 1 to 14, 30, and 90. The primary outcome to be tested is safety. Secondary tested outcomes include changes of hematoma and perihematomal edema volume, incidence of hematoma expansion, functional outcomes, and frequency of adverse events. Discussions: This study will be the first proof-of-concept randomized controlled trial to ascertain the safety, feasibility, and preliminary efficacy of RIC in patients with ICH, results of which will provide parameters for future studies and provide insights into the treatment of ICH. Trial Registration: Clinicaltrials.gov, identifier: NCT03930940.

Antihyperthermic treatment decreases perihematomal hypodensity

OBJECTIVE

To investigate the effect on perihematomal hypodensity and outcome of a decrease in body temperature in the first 24 hours in patients with intracerebral hemorrhage (ICH).

METHODS

In this retrospective study on a prospectively registered database, among the 1,100 patients, 795 met all the inclusion criteria. Temperature variations in the first 24 hours and perihematomal hypodensity (PHHD) were recorded. Patients ≥37.5°C were treated with antihyperthermic drugs for at least 48 hours. The main objective was to determine the association among temperature variation, PHHD, and outcome at 3 months.

RESULTS

The decrease in temperature in the first 24 hours increased the possibility of good outcome 11-fold. Temperature decrease, lower PHHD volume, and a good outcome were observed in 31.8% of the patients who received antihyperthermic treatment.

CONCLUSION

The administration of early antihyperthermic treatment in patients with spontaneous ICH with a basal axillary temperature ≥37.5°C resulted in good outcome in a third of the treated patients.

Hydrochloride fasudil attenuates brain injury in ICH rats

Aim

The aim of this study was to investigate the neuroprotective effects of hydrochloride fasudil (HF) in rats following intracerebral hemorrhage (ICH).

Methods

Male Wistar rats were randomly divided into four groups: normal, sham-operated, ICH, and ICH/HF. ICH was induced by injection of non-anticoagulant autologous arterial blood into the right caudate nucleus. The levels of Rho-associated protein kinase 2 (ROCK2) mRNA and protein around the site of the hematoma were measured by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA), respectively. The levels of interleukin-6 and tumor necrosis factor-α in serum were detected by ELISA. The inflammatory cells and changes in the neuronal morphology around the hematoma were visualized using hematoxylin and eosin and Nissl staining. Brain edema was measured by comparing wet and dry brain weights.

Results

Following ICH, the levels of ROCK2 were significantly increased from day 1 to day 7. The levels of ROCK2 were significantly lower in rats treated with HF than in controls. The levels of inflammatory cytokines and brain water content were significantly higher in rats treated with HF than in controls. Administration of HF significantly reduced the levels of inflammatory cytokines and brain water content from day 1 to day 7. In the acute phase of ICH, a large number of neutrophils infiltrated the perihematomal areas. In comparison with the ICH group, the ICH/HF group showed markedly fewer infiltrating neutrophils on day 1. Nissl staining showed that ICH caused neuronal death and loss of neurons in the perihematomal areas at all time points and that treatment with HF significantly attenuated neuronal loss.

Conclusions

HF exerts neuroprotective effects in ICH rats by inhibiting the expression of ROCK2, reducing neutrophil infiltration and production of inflammatory cytokines, decreasing brain edema, and attenuating loss of neurons.

Bone marrow mesenchymal stem cells transplantation alleviates brain injury after intracerebral hemorrhage in mice through the Hippo signaling pathway

Intracerebral hemorrhage (ICH) is a common acute nervous system disease with high mortality and severe disability. Mesenchymal stem cells (MSCs) have been reported to promote neurogenesis and to alleviate side effects in areas of brain injury areas. The Hippo pathway regulates diverse cellular processes, including cell survival, proliferation, differentiation, and organ size. Here, we found that transplantation of bone marrow MSCs (BM-MSCs) into the brains of mice could alleviate ICH-mediated injury and protect astrocytes from apoptosis by regulating mammalian sterile 20-like kinase (MST)1 and Yes-associated protein (YAP). Knocking down of MST1 by si-RNA triggered YAP nuclear translocation. We further demonstrated that astrocytes undergo astroglial-mesenchymal phenotype switching and become capable of proliferating after BM-MSC transplantation via the Hippo signaling pathway. Together, our identification of the Hippo pathway in mediating the beneficial effects of BM-MSCs may provide a novel therapeutic target in the treatment and management of ICH.

Antithrombotics in intracerebral hemorrhage in the era of novel agents and antidotes: A review

BACKGROUND

Intracerebral hemorrhage (ICH)1 is characterized by the pathological accumulation of blood within the brain parenchyma, most commonly associated with hypertension, arteriovenous malformations, or trauma. However, it can also present in patients receiving antithrombotic drugs, either anticoagulants such as acenocoumarol/warfarin-novel oral anticoagulants or antiplatelets, for the prevention and treatment of thromboembolic disease.

OBJECTIVE

The purpose of this review is to present current bibliographic data regarding ICH irrespective of the cause, as well as post-hemorrhage use of antithrombotic agents. Moreover, this review attempts to provide guidelines concerning the termination, inversion, and of course resumption of antithrombotic therapy.

METHODS AND MATERIALS

We reviewed the most recently presented available data for patients who dealt with intracerebral hemorrhagic events while on antithrombotic agents (due to atrial fibrillation, prosthetic mechanical valves or recent/recurrent deep vein thrombosis). Furthermore, we examined and compared the thromboembolic risk, the bleeding risk, as well as the re-bleeding risk in two groups: patients receiving antithrombotic therapy versus patients not on antithrombotic therapy.

CONCLUSION

Antithrombotic therapy is of great importance when indicated, though it does not come without crucial side-effects, such as ICH. Optimal timing of withdrawal, reversal, and resumption of antithrombotic treatment should be determined by a multidisciplinary team consisting of a stroke specialist, a cardiologist, and a neurosurgeon, who will individually approach the needs and risks of each patient.

Intracerebral Hemorrhage Induced Brain Injury Is Mediated by the Interleukin-12 Receptor in Rats

BACKGROUND

IL-12 inhibition of the endothelial cell functions and angiogenesis is mediated by the cross-talk between the lymphocyte and the endothelial cells, which plays a key role in inhibiting the process of angiogenesis in the eyeballs and in malignant tumors.

METHODS

We established the intracerebral hemorrhage (ICH) rat model, and IL-12 receptor beta monoclonal antibody was injected into the ICH rats. Western blot, immunofluorescence and RT-qPCR were used to detect the gene expression. Brain water content, EB staining, Garcia test, Beam walking test and wire hanging test were used to assess the injury of brain in ICH rats.

RESULTS

IL-12 gene was significantly increase in hematoma border tissue of ICH rats, and IL-12 protein mainly localized in monocytes. Anti-IL-12 treatment with IL-12 monoclonal antibodies could not only significantly decrease the brain water content and EB content in brain tissues of ICH rats, but also significantly increase the score of the Garcia, Beam balance and the Wire hanging test in ICH rats. Moreover, anti-IL-12 treatment significantly decrease the expression of pro-inflammatory gene, inflammatory gene, p-JAK2/JAK2 and p-STAT4/STAT4 protein, but significantly increase the expression anti-inflammatory gene and CD31 protein, and M2 macrophage ratio in hematoma border tissues of ICH rats. In vitro, rmIL-12 inhibited the tube formation of brain microvascular endothelial cells (BMVES) in BMVES and bone marrow-derived monocytes (BMDM) co-culture systems, but not work in a separately cultured BMVES system. In addition, Fedratinib not only reduced p-JAK2/JAK2 and p-STAT4/STAT4 protein expression in BMDM after treating with b-FGF and rmIL-12, but also significantly increased the tube formation of BMVES in BMVES and BMDM co-culture systems after treating with b-FGF and rmIL-12.

CONCLUSION

Blockade of IL-12 receptor attenuated brain injury after ICH in rat by promoting angiogenesis, and the mechanism might be related to blocking IL-12 could inhibit M2 cell activation via the JAK2/STAT4 pathway.

MicroRNA and their target mRNAs change expression in whole blood of patients after intracerebral hemorrhage

Previous studies showed changes in mRNA levels in whole blood of rats and humans, and in miRNA in whole blood of rats following intracerebral hemorrhage (ICH). Thus, this study assessed miRNA and their putative mRNA targets in whole blood of humans following ICH. Whole transcriptome profiling identified altered miRNA and mRNA levels in ICH patients compared to matched controls. Target mRNAs of the differentially expressed miRNAs were identified, and functional analysis of the miRNA-mRNA targets was performed. Twenty-nine miRNAs (22 down, 7 up) and 250 target mRNAs (136 up, 114 down), and 7 small nucleolar RNA changed expression after ICH compared to controls (FDR < 0.05, and fold change ≥ |1.2|). These included Let7i, miR-146a-5p, miR210-5p, miR-93-5p, miR-221, miR-874, miR-17-3p, miR-378a-5p, miR-532-5p, mir-4707, miR-4450, mir-1183, Let-7d-3p, miR-3937, miR-4288, miR-4741, miR-92a-1-3p, miR-4514, mir-4658, mir-3689d-1, miR-4760-3p, and mir-3183. Pathway analysis showed regulated miRNAs/mRNAs were associated with toll-like receptor, natural killer cell, focal adhesion, TGF-β, phagosome, JAK-STAT, cytokine-cytokine receptor, chemokine, apoptosis, vascular smooth muscle, and RNA degradation signaling. Many of these pathways have been implicated in ICH. The differentially expressed miRNA and their putative mRNA targets and associated pathways may provide diagnostic biomarkers as well as point to therapeutic targets for ICH treatments in humans.

The emerging role of ferroptosis in inflammation

Ferroptosis is a newly discovered type of cell death triggered by intracellular phospholipid peroxidation that is morphologically, biologically and genetically distinct from other types of cell death. Ferroptosis is classified as regulated necrosis and is more immunogenic than apoptosis. To date, compelling evidence indicates that ferroptosis plays an important role in inflammation, and several antioxidants functioning as ferroptosis inhibitors have been shown to exert anti-inflammatory effects in experimental models of certain diseases. Our review provides an overview of the link between ferroptosis and inflammation; a better understanding of the mechanisms underlying ferroptosis and inflammation may hasten the development of promising therapeutic strategies involving ferroptosis inhibitors to address inflammation.

A Role for Endoplasmic Reticulum Stress in Intracerebral Hemorrhage

The endoplasmic reticulum (ER) is an intracellular organelle that performs multiple functions, such as lipid biosynthesis, protein folding, and maintaining intracellular calcium homeostasis. Thus, conditions wherein the ER is unable to fold proteins is defined as ER stress, and an inbuilt quality control mechanism, called the unfolded protein response (UPR), is activated during ER stress, which serves as a recovery system that inhibits protein synthesis. Further, based on the severity of ER stress, the response could involve both proapoptotic and antiapoptotic phases. Intracerebral hemorrhage (ICH) is the second most common subtype of cerebral stroke and many lines of evidence have suggested a role for the ER in major neurological disorders. The injury mechanism during ICH includes hematoma formation, which in turn leads to inflammation, elevated intracranial pressure, and edema. A proper understanding of the injury mechanism(s) is required to effectively treat ICH and closing the gap between our current understanding of ER stress mechanisms and ICH injury can lead to valuable advances in the clinical management of ICH.

A Comparison of Motor Functional Recovery and Brain Damage between Striatal Lesions Induced by Ischemia and Hemorrhage in Rats

BACKGROUND

The purpose of this study was to evaluate the natural recovery process and tissue injury associated with cerebral hemorrhage and cerebral infarction, which were induced to the same degree, in the striatum of rats.

METHODS

Male Wistar rats were divided into intracerebral hemorrhagic (ICH) and ischemia (ISC) groups, with the ICH group injected with a collagenase solution and the ISC group injected with an endothelin-1 solution. In the SHAM group, physiological saline was injected. Motor function was evaluated by the ladder and forelimb placing tests on the first day before surgery and the first, seventh, and 14th day after surgery. On day 15 after surgery, brain tissue was harvested and frozen sections were prepared. Nissl staining was performed, and the tissue loss, ventricular, and hemispheric volumes were analyzed.

RESULTS

On the first day of surgery, the ICH group had significantly decreased motor function compared with the ISC group. However, subsequent recovery of motor function was faster in the ICH group than that in the ISC group. In addition, tissue loss and hemispheric volumes were significantly higher in the ISC group than those in the ICH group, whereas the ventricular volume was significantly higher in the ICH group than that in the ISC group.

CONCLUSIONS

Collectively, our findings indicate that, in ICH and ISC where the brain damage involves the same site and is approximately the same size, motor function is recovered faster in ICH than that in ISC. As such, differences in secondary degeneration are likely affected.

Emerging promise of sulforaphane-mediated Nrf2 signaling cascade against neurological disorders

Neurological disorders represent a great challenge and are the leading cause of death and disability globally. Although numerous complicated mechanisms are involved in the progressions of chronic and acute neurodegenerative disorders, most of the diseases share mutual pathogenic features such as oxidative stress, mitochondrial dysfunction, neuroinflammation, protein misfolding, excitotoxicity, and neuronal damage, all of these are the common targets of nuclear factor erythroid 2 related factor 2 (Nrf2) signaling cascade. No cure has yet been discovered to tackle these disorders, so, intervention approaches targeting phytochemicals have been recommended as an alternative form of treatment. Sulforaphane is a sulfur-rich dietary phytochemical which has several activities such as antioxidant, anti-inflammatory, and anti-tumor via multiple targets and various mechanisms. Given its numerous actions, sulforaphane has drawn considerable attention for neurological disorders in recent years. Nrf2 is one of the most crucial targets of sulforaphane which has potential in regulating the series of cytoprotective enzyme expressions that have neuroprotective, antioxidative, and detoxification actions. Neurological disorders are auspicious candidates for Nrf2-targeted treatment strategy. Sulforaphane protects various neurological disorders by regulating the Nrf2 pathway. In this article, we recapitulate current studies of sulforaphane-mediated Nrf2 activation in the treatment of various neurological disorders.

Intracranial Pressure Monitoring-Aided Management Associated with Favorable Outcomes in Patients with Hypertension-Related Spontaneous Intracerebral Hemorrhage

To investigate the effect of intracranial pressure (ICP) monitoring on the functional outcome of patients with hypertension-related spontaneous intracerebral hemorrhage (ICH). We included 196 patients with Glasgow Coma Scale (GCS) scores of 3-12 in this observational study, of which 103 underwent ICP monitors. Binary and ordinal regression analyses were used to estimate the effect of ICP monitoring on the functional outcome. The rate of adverse events, blood pressure control, and length of hospitalization were compared between the two groups. ICP monitoring had a significant impact on the clinical outcome of patients by shifting the Extended Glasgow Outcome Scale (GOS-E) scores in a favorable direction (p = 0.027) and reducing mortality at discharge (p = 0.004) and 6 months later (p = 0.02). The rate of favorable outcome at 6 months was higher in the ICP-monitored group (p = 0.03). However, subgroup analysis showed that no relationship between ICP monitoring and clinical outcome was found for patients with GCS scores of 3-8. For patients with GCS scores of 9-12, the distribution of GOS-E scores at 6 months shifted in a favorable direction in the ICP-monitored group (p = 0.001). The rate of favorable outcome at 6 months was higher in the ICP-monitored group (p = 0.01). The mortality at discharge and 6 months later was also lower in the ICP-monitored group. Thus, our study supports the value of ICP monitoring in hypertension-related ICH patients with GCS scores of 3-12, especially those with GCS scores of 9-12.

Neuroprotective functions of calycosin against intracerebral hemorrhage-induced oxidative stress and neuroinflammation

Aim: To investigate whether calycosin affects the brain damages induced by intracerebral hemorrhage (ICH). Methods: ICH mouse model was established by injection of collagenase type VII. Results: 50 mg/kg calycosin showed significant inhibitory effects on ICH-induced brain impairment evaluated by modified neurologic severity scores and water content. In addition, the lesion volumes, blood accumulation and hemispheric enlargement were all dramatically reduced by calycosin treatment compared with those of vehicles. It was observed that calycosin repressed oxidative stress by enhancing Nrf2 anti-oxidative pathway and suppressed inflammation by blocking NACHT, NALP3 inflammasome and NF-κB pathway activation. Conclusion: Calycosin could protect the brain against the damages induced by ICH via inhibiting oxidative damages and inflammation.

Time Trends in Survival Following First Hemorrhagic or Ischemic Stroke Between 1991 and 2015 in the Rotterdam Study

Background and Purpose—

The introduction of stroke units and the implementation of evidence-based interventions have been a breakthrough in the management of patients with stroke over the past decade. Survival following stroke is an important indicator in monitoring stroke burden. Recent data on survival by stroke subtype in the general population is scarce. We assessed (1) recent temporal time trends in survival; (2) age-standardized death rates; (3) survival probabilities at 6 months, 1, 2, and 3 years following first hemorrhagic or ischemic stroke.

Methods—

Within the population-based Rotterdam Study between 1991 and 2015, we assessed time trends in survival among 162 with first-ever hemorrhagic and 988 patients with first-ever ischemic stroke across 3 time periods (1991–1998; 1999–2007; 2008–2015) using time-varying Cox regression model and calculated age-standardized death rates according to the European 2010 census population.

Results—

In the hemorrhagic stroke group, a total of 144 deaths occurred during 386 person-years. Following a hemorrhagic stroke, we observed similar mortality rates over the years with 30 per 100 person-years in 2015 compared with 25/100 person-years in 1991. Similarly, compared with the earliest study period (1991–1998), mortality rates remained unchanged in the latest study period (2008–2015; hazard ratio, 0.97 [95% CI, 0.61–1.57]; P =0.93). In the ischemic stroke group, a total of 711 deaths occurred during 4897 person-years. We observed a decline in mortality rates in 2015 (11 per 100 person-years) compared with 1991 (29/100 person-years). This translated to favorable trends in the latest study period 2008 to 2015 (hazard ratio, 0.71 [95% CI, 0.56–0.90]; P <0.01).

Conclusions—

Survival following ischemic stroke has improved over the past decade, while no change was observed in survival following hemorrhagic stroke.

Luteolin alleviates neuroinflammation via downregulating the TLR4/TRAF6/NF-κB pathway after intracerebral hemorrhage

The activation of microglia and inflammatory responses is essential for the process of intracerebral hemorrhage (ICH)-induced secondary brain injury (SBI). In this study, we investigated the effects of luteolin on ICH-induced SBI and the potential mechanisms. Autologous blood was injected to establish the ICH model in vivo, and oxyhemoglobin (OxyHb) was used to mimic the ICH model in vitro. We found that the administration of luteolin significantly improved motor and sensory impairments and inhibited neuronal cell degeneration in vivo. In the in vitro study, the decrease of the neuronal cell viability induced by activated microglia was alleviated by luteolin treatment. Furthermore, by antagonizing the activation of the Toll-like receptor 4 (TLR4)/TNF receptor-associated factor 6 (TRAF6)/nuclear transcription factor-κB (NF-κB) signaling pathway, the ICH-induced elevation of cytokine release was decreased after treatment with luteolin, which was confirmed both in vivo and in vitro. Additionally, we found that luteolin engaged with TRAF6 and inhibited the ubiquitination of TRAF6. Taken together, our findings demonstrate the neuroprotective effects of luteolin after ICH and the potential mechanisms, which suggest that luteolin is a potential therapeutic candidate for ICH treatment.

Histone Deacetylation 10 Alleviates Inflammation After Intracerebral Hemorrhage via the PTPN22/NLRP3 Pathway in Rats

The NOD-like receptor family Pyrin domain-containing 3 (NLRP3) inflammasome has a crucial role in the inflammatory process that occurs during intracerebral hemorrhage (ICH)-induced injury. Histone deacetylase 10 (HDAC10) is a newly identified class II histone deacetylase involved in immune responses. However, how HDAC10 affects the inflammatory response after ICH remains unknown. In this study, we investigated whether HDAC10 relieves ICH injury by suppressing NLRP3 inflammasome activation through the protein tyrosine phosphatase, nonreceptor type 22 (PTPN22) pathway. We induced ICH in Sprague-Dawley rats (healthy, male adult) with a single infusion of autologous blood. To knockdown HDAC10, we injected siRNA into the rats. To further explore the mechanisms underlying the role of HDAC10 in ICH injury, PTPN22 was silenced. HDAC10 levels were upregulated after ICH in humans and rats, and reached peak levels 24 h after ICH induction in rats. HDAC10 silencing aggravated ICH injury, as demonstrated by increased modified neurological severity scores, brain water content, Evans blue extravasation, and number of myeloperoxidase (MPO) cells, and the results of Nissl and H&E staining. Furthermore, HDAC10 knockdown increased the expression of PTPN22 and accentuated inflammatory responses mediated by the NLRP3 inflammasome. HDAC10 silencing increased NLRP3 inflammasome activation, and this was effectively reversed by PTPN22 knockdown using siRNA. Furthermore, HDAC10 silencing also promoted the interaction of PTPN22 and NLRP3. Our study demonstrated that HDAC10 silencing aggravated NLRP3-mediated inflammatory responses after ICH in rats via the PTPN22 pathway. These results suggest that regulating the NLRP3 inflammasome may be a novel method to ameliorate ICH injury.

MST4 Kinase Inhibitor Hesperadin Attenuates Autophagy and Behavioral Disorder via the MST4/AKT Pathway in Intracerebral Hemorrhage Mice

Background

The aim of this study was to explore the role of hesperadin in intracerebral hemorrhage (ICH) mice, with the involvement of the mammalian ste20-like kinase 4 (MST4)/AKT signaling pathway.

Methods

All mice were divided into four groups: sham group, sham+hesperidin group, ICH group, and ICH+hesperadin group. The effects of hesperadin were assessed on the basis of brain edema and neurobehavioral function. Furthermore, we observed MST4, AKT, phosphorylation of AKT (pAKT), and microtubule-associated protein light chain 3 (LC3) by western blotting. Protein localization of MST4 and LC3 was determined by immunofluorescence.

Results

The expression of MST4 was upregulated at 12 h and 24 h after ICH. Brain edema was significantly decreased and neurological function was improved in the hesperadin treatment group compared to the ICH group (P < 0.05). Hesperadin decreases the expressions of MST and increases pAKT after ICH. Autophagy significantly increased in the ICH group, while hesperadin reduced this increase.

Conclusion

Hesperadin provides neuroprotection against ICH by inhibiting the MST4/AKT signaling pathway.

Multinucleated Giant Cells in Experimental Intracerebral Hemorrhage

Macrophage phagocytosis plays an important role in hematoma clearance after intracerebral hemorrhage (ICH). This study examined the characteristics of multinucleated giant cells (MGCs), a group of macrophages with multiple nuclei, in a mouse ICH model. Whether MGCs could be increased by treatment with a CD47 blocking antibody and decreased by treatment with clodronate liposomes were also examined. ICH was induced via autologous blood injection. Male adult C57BL/6 mice in different groups had (1) ICH alone; (2) ICH with anti-CD47 blocking antibody or control IgG; and (3) ICH with anti-CD47 antibody combined with clodronate liposomes or control liposomes. The effect of anti-CD47 antibody on MGC formation was also tested in females. Brains were harvested at days 3 or 7 for brain histology. Many MGCs were found at day 3 post-ICH, but were reduced at day 7. MGCs phagocytosed many red blood cells and were heme oxygenase-1, ferritin, YM-1, and iNOS positive. CD47 blocking antibody injection increased MGC numbers in the peri-hematomal zone and in the hematoma in both sexes. Co-injection of clodronate liposomes depleted MGCs in both the hematoma core and the peri-hematomal area. In conclusion, MGCs represent a macrophage/microglia subtype with strong phagocytosis capacity. MGCs exhibited not only an M2 but also an M1 phenotype and appeared involved in hemoglobin degradation. Anti-CD47 antibody boosted the number of MGCs, which may contribute to enhance hematoma clearance. Understanding the exact roles of MGCs in ICH may reveal novel targets for ICH treatment.

Fully Automated Segmentation Algorithm for Perihematomal Edema Volumetry After Spontaneous Intracerebral Hemorrhage

Background and Purpose- Perihematomal edema (PHE) is a promising surrogate marker of secondary brain injury in patients with spontaneous intracerebral hemorrhage, but it can be challenging to accurately and rapidly quantify. The aims of this study are to derive and internally validate a fully automated segmentation algorithm for volumetric analysis of PHE. Methods- Inpatient computed tomography scans of 400 consecutive adults with spontaneous, supratentorial intracerebral hemorrhage enrolled in the Intracerebral Hemorrhage Outcomes Project (2009-2018) were separated into training (n=360) and test (n=40) datasets. A fully automated segmentation algorithm was derived from manual segmentations in the training dataset using convolutional neural networks, and its performance was compared with that of manual and semiautomated segmentation methods in the test dataset. Results- The mean volumetric dice similarity coefficients for the fully automated segmentation algorithm were 0.838±0.294 and 0.843±0.293 with manual and semiautomated segmentation methods as reference standards, respectively. PHE volumes derived from the fully automated versus manual (r=0.959; P<0.0001), fully automated versus semiautomated (r=0.960; P<0.0001), and semiautomated versus manual (r=0.961; P<0.0001) segmentation methods had strong between-group correlations. The fully automated segmentation algorithm (mean 18.0±1.8 seconds/scan) quantified PHE volumes at a significantly faster rate than both of the manual (mean 316.4±168.8 seconds/scan; P<0.0001) and semiautomated (mean 480.5±295.3 seconds/scan; P<0.0001) segmentation methods. Conclusions- The fully automated segmentation algorithm accurately quantified PHE volumes from computed tomography scans of supratentorial intracerebral hemorrhage patients with high fidelity and greater efficiency compared with manual and semiautomated segmentation methods. External validation of fully automated segmentation for assessment of PHE is warranted.

MicroRNA Regulatory Network as Biomarkers of Late Seizure in Patients with Spontaneous Intracerebral Hemorrhage

Approximately 15% of patients experience seizures after spontaneous intracerebral hemorrhage (ICH). The pathogenesis of seizures post-ICH is not well-known; however, iron deposition-related neuronal injury following hemoglobin breakdown may contribute. Profiling known miRNAs to identify biomarkers for post-ICH late seizures, we found 64 differentially expressed miRNA: 32 upregulated and 32 downregulated in seizure vs. non-seizure. Functional classification of upregulated miRNA for KEGG pathways and biological processes identified enrichment for cell cycle, protein modifications, and FoxO neurotrophin signaling pathways. No significant enrichment was found for downregulated miRNA. Molecular functions Gene Ontology (GO) terms enriched for upregulated miRNA are numerous, while downregulated miRNAs were associated with ion channel activity. RT-PCR confirmed two miRNAs, 4317 and 4325, were differentially expressed in patients who developed seizures at 1 year. MiR-4317 regulates SLC38A1, a glutamine-glutamate transporter. Integrated miRNA-mRNA network analysis identified COMMD6, APOBEC2, and RASSF6-involved in NF-kB regulation. Two miRNAs (miR-4317 and 4325) differentiated post-ICH late seizures vs. non-seizures at 1 year. The results suggest functional and miRNA-mRNA networks as potential biomarkers for post-ICH late seizures.

Excessive antibiotics use increased in-hospital mortality in intracerebral hemorrhage patients with stroke-associated infection

Intracerebral hemorrhage (ICH) is associated with higher incidence of stroke-associated infection (SAI) as well as antibiotic use. However, there were few methods for judging proper antibiotic use in clinical manner. We introduce an index of antibiotic use, called personal antibiotic use density (PAUD), to evaluate the relation between antibiotic use and prognosis of ICH patients with SAI. A total of 162 in 570 ICH patients were observed to diagnose as SAI. Comparing with the survival patients, PAUD, ICH volume, National Institutes of Health Stroke Scale (NIHSS) score and ICH score were significantly higher among those who died, while the Glasgow Coma Scale score and the length of stay were significantly lower (P < 0.05). PAUD was identified as an independent risk factor of in-hospital death (OR 2.396, 95% CI 1.412-4.067, P = 0.001). In-hospital mortality was significantly lower in the low (P = 0.027) and intermediate PAUD (P < 0.001) groups than that in the high PAUD group. Cumulative in-hospital survival was significantly higher in low and intermediate PAUD groups (log rank test, P < 0.001). PAUD correlated positively with NIHSS score (r = 0.224, P < 0.001) and in-hospital mortality (r = 0.268, P = 0.001). The study indicated that PAUD is closely related to in-hospital prognosis of ICH patients with SAI. Higher PAUD may not be associated with better prognosis, but instead, higher risk of death.

IL (Interleukin)-15 Bridges Astrocyte-Microglia Crosstalk and Exacerbates Brain Injury Following Intracerebral Hemorrhage

Background and Purpose- Microglia are among the first cells to respond to intracerebral hemorrhage (ICH), but the mechanisms that underlie their activity following ICH remain unclear. IL (interleukin)-15 is a proinflammatory cytokine that orchestrates homeostasis and the intensity of the immune response following central nervous system inflammatory events. The goal of this study was to investigate the role of IL-15 in ICH injury. Methods- Using brain slices of patients with ICH, we determined the presence and cellular source of IL-15. A transgenic mouse line with targeted expression of IL-15 in astrocytes was generated to determine the role of astrocytic IL-15 in ICH. The expression of IL-15 was controlled by a glial fibrillary acidic protein promoter (GFAP-IL-15^tg). ICH was induced by intraparenchymal injection of collagenase or autologous blood. Results- In patients with ICH and wild-type mice subjected to experimental ICH, we found a significant upregulation of IL-15 in astrocytes. In GFAP-IL-15^tg mice, we found that astrocyte-targeted expression of IL-15 exacerbated brain edema and neurological deficits following ICH. This aggravated ICH injury in GFAP-IL-15^tg mice is accompanied by increased microglial accumulation in close proximity to astrocytes in perihematomal tissues. Additionally, microglial expression of CD86, IL-1β, and TNF-α is markedly increased in GFAP-IL-15^tg mice following ICH. Furthermore, depletion of microglia using a colony stimulating factor 1 receptor inhibitor diminishes the exacerbation of ICH injury in GFAP-IL-15^tg mice. Conclusions- Our findings identify IL-15 as a mediator of the crosstalk between astrocytes and microglia that exacerbates brain injury following ICH.

Neuroinflammation after Intracerebral Hemorrhage and Potential Therapeutic Targets

Spontaneous intracerebral hemorrhage (ICH) is a catastrophic illness causing significant morbidity and mortality. Despite advances in surgical technique addressing primary brain injury caused by ICH, little progress has been made treating the subsequent inflammatory cascade. Pre-clinical studies have made advancements identifying components of neuroinflammation, including microglia, astrocytes, and T lymphocytes. After cerebral insult, inflammation is initially driven by the M1 microglia, secreting cytokines (e.g., interleukin-1β [IL-1β] and tumor necrosis factor-α) that are involved in the breakdown of the extracellular matrix, cellular integrity, and the blood brain barrier. Additionally, inflammatory factors recruit and induce differentiation of A1 reactive astrocytes and T helper 1 (Th1) cells, which contribute to the secretion of inflammatory cytokines, augmenting M1 polarization and potentiating inflammation. Within 7 days of ICH ictus, the M1 phenotype coverts to a M2 phenotype, key for hematoma removal, tissue healing, and overall resolution of inflammation. The secretion of anti-inflammatory cytokines (e.g., IL-4, IL-10) can drive Th2 cell differentiation. M2 polarization is maintained by the secretion of additional anti-inflammatory cytokines by the Th2 cells, suppressing M1 and Th1 phenotypes. Elucidating the timing and trigger of the anti-inflammatory phenotype may be integral in improving clinical outcomes. A challenge in current translational research is the absence of an equivalent disease animal model mirroring the patient population and comorbid pathophysiologic state. We review existing data and describe potential therapeutic targets around which we are creating a bench to bedside translational research model that better reflects the pathophysiology of ICH patients.

The Mitochondria-Derived Peptide Humanin Improves Recovery from Intracerebral Hemorrhage: Implication of Mitochondria Transfer and Microglia Phenotype Change

Astrocytes are an integral component of the neurovascular unit where they act as homeostatic regulators, especially after brain injuries, such as stroke. One process by which astrocytes modulate homeostasis is the release of functional mitochondria (Mt) that are taken up by other cells to improve their function. However, the mechanisms underlying the beneficial effect of Mt transfer are unclear and likely multifactorial. Using a cell culture system, we established that astrocytes release both intact Mt and humanin (HN), a small bioactive peptide normally transcribed from the Mt genome. Further experiments revealed that astrocyte-secreted Mt enter microglia, where they induce HN expression. Similar to the effect of HN alone, incorporation of Mt by microglia (1) upregulated expression of the transcription factor peroxisome proliferator-activated receptor gamma and its target genes (including mitochondrial superoxide dismutase), (2) enhanced phagocytic activity toward red blood cells (an in vitro model of hematoma clearance after intracerebral hemorrhage [ICH]), and (3) reduced proinflammatory responses. ICH induction in male mice caused profound HN loss in the affected hemisphere. Intravenously administered HN penetrated perihematoma brain tissue, reduced neurological deficits, and improved hematoma clearance, a function that normally requires microglia/macrophages. This study suggests that astrocytic Mt-derived HN could act as a beneficial secretory factor, including when transported within Mt to microglia, where it promotes a phagocytic/reparative phenotype. These findings also indicate that restoring HN levels in the injured brain could represent a translational target for ICH. These favorable biological responses to HN warrant studies on HN as therapeutic target for ICH.SIGNIFICANCE STATEMENT Astrocytes are critical for maintaining brain homeostasis. Here, we demonstrate that astrocytes secrete mitochondria (Mt) and the Mt-genome-encoded, small bioactive peptide humanin (HN). Mt incorporate into microglia, and both Mt and HN promote a "reparative" microglia phenotype characterized by enhanced phagocytosis and reduced proinflammatory responses. Treatment with HN improved outcomes in an animal model of intracerebral hemorrhage, suggesting that this process could have biological relevance to stroke pathogenesis.

Ghrelin attenuates secondary brain injury following intracerebral hemorrhage by inhibiting NLRP3 inflammasome activation and promoting Nrf2/ARE signaling pathway in mice

Ghrelin, a brain-gut peptide, has been proven to exert neuroprotection in different kinds of neurological diseases; however, its role and the potential molecular mechanisms in secondary brain injury (SBI) after intracerebral hemorrhage (ICH) are still unknown. In this study, we investigate whether treatment with ghrelin may attenuate SBI in a murine ICH model, and if so, whether the neuroprotective effects are due to the inhibition of nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (NLRP3) inflammasome activation and promotion of nuclear factor-E2-related factor 2 (Nrf2)/antioxidative response element (ARE) signaling pathway. Stereotactically intrastriatal infusion of autologous blood was performed to mimic ICH. Ghrelin was given intraperitoneally immediately following ICH and again 1 h later. Results showed that ghrelin attenuated neurobehavioral deficits, brain edema, hematoma volume, and perihematomal cell death post-ICH. Ghrelin inhibited the NLRP3 inflammasome activation and subsequently suppressed the neuroinflammatory response as evidenced by reduced microglia activation, neutrophil infiltration, and pro-inflammatory mediators release after ICH. Additionally, ghrelin alleviated ICH-induced oxidative stress according to the chemiluminescence of luminol and lucigenin, malondialdehyde (MDA) content, and total superoxide dismutase (SOD) activity assays. These changes were accompanied by upregulation of Nrf2 expression, Nrf2 nuclear accumulation, and enhanced Nrf2 DNA binding activity, as well as by increased expressions of Nrf2 downstream target antioxidative genes, including NAD(P)H quinine oxidoreductase-1 (NQO1), glutathione cysteine ligase regulatory subunit (GCLC), and glutathione cysteine ligase modulatory subunit (GCLM). Together, our data suggested that ghrelin protected against ICH-induced SBI by inhibiting NLRP3 inflammasome activation and promoting Nrf2/ARE signaling pathway.

The Role of Urocortins in Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) causes an accumulation of blood in the brain parenchyma that disrupts the normal neurological function of the brain. Despite extensive clinical trials, no medical or surgical therapy has shown to be effective in managing ICH, resulting in a poor prognosis for the patients. Urocortin (UCN) is a 40-amino-acid endogenous neuropeptide that belongs to the corticotropin-releasing hormone (CRH) family. The effect of UCN is activated by binding to two G-protein coupled receptors, CRH-R1 and CRH-R2, which are expressed in brain neurons and glial cells in various brain regions. Current research has shown that UCN exerts neuroprotective effects in ICH models via anti-inflammatory effects, which generally reduced brain edema and reduced blood-brain barrier disruption. These effects gradually help in the improvement of the neurological outcome, and thus, UCN may be a potential therapeutic target in the treatment of ICH. This review summarizes the data published to date on the role of UCN in ICH and the possible protective mechanisms underlined.

Comparison of epidemiological and clinical features between two chronological cohorts of patients with intracerebral hemorrhage

To investigate the differences in the epidemiological and clinical characteristics of patients with intracerebral hemorrhage (ICH) treated at our institution over the last few decades. Two chronological cohorts with ten-year-interval were established and epidemiological and clinical data were retrospectively collected from patients with ICH, and data were analyzed using SPSS 13.0. The time windows for the two cohorts were from January 1, 2010 to December 31, 2014 (2010-2014 cohort) and January 1, 2000 to December 31, 2004 (2000-2004 cohort). 1598 patients with ICH were enrolled: 360 patients in the 2000-2004 cohort and 1238 patients in the 2010-2014 cohort. ICH often occurred in patients aged from 45 to 75 years, without a sex bias, accounting for 69.6% of patients. Hypertension (60.7%) was still the main risk factors. Meanwhile, the risk factors of smoking (28.9%) and drinking (23.3%) were often present in male patients but not female patients (p ≤ 0.001). The incidence of pulmonary infection, the main complication during hospitalization, was 40.8% in the 2000-2004 cohort and 61.8% in the 2010-2014 cohort (p ≤ 0.001). Moreover, the incidence of gastrointestinal hemorrhage was 12.5% in the 2000-2004 cohort and 6.0% in the 2010-2014 cohort (p ≤ 0.001). The epidemiological and clinical features have changed over the past 10 years. The mortality was reduced but still high, as evidenced by the increased hospitalization rate of patients with ICH. Current preventions and therapeutic strategies for ICH are effective, but more strategies must be developed to improve the outcome of ICH and decrease the incidence of pulmonary infection.

MicroRNA-181c provides neuroprotection in an intracerebral hemorrhage model

Apoptosis is an important factor during the early stage of intracerebral hemorrhage. MiR-181c plays a key regulatory role in apoptosis. However, whether miR-181c is involved in apoptosis of prophase cells after intracerebral hemorrhage remains unclear. Therefore, in vitro and in vivo experiments were conducted to test this hypothesis. In vivo experiments: collagenase type VII was injected into the basal ganglia of adult Sprague-Dawley rats to establish an intracerebral hemorrhage model. MiR-181c mimic or inhibitor was injected in situ 4 hours after intracerebral hemorrhage. Neurological functional defects (neurological severity scores) were assessed 1, 7, and 14 days after model establishment. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling and western blot assay were conducted 14 days after model establishment. In vitro experiments: PC12 cells were cultured under oxygen-glucose deprivation, and hemins were added to simulate intracerebral hemorrhage in vitro. MiR-181c mimic or inhibitor was added to regulate miR-181c expression. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, luciferase reporter system, and western blot assay were performed. Experimental results revealed differences in miR-181c expression in brain tissues of both patients and rats with cerebral hemorrhage. In addition, in vitro experiments found that miR-181c overexpression could upregulate the Bcl-2/Bax ratio to inhibit apoptosis, while inhibition of miR-181c expression could reduce the Bcl-2/Bax ratio and aggravate apoptosis of cells. Regulation of apoptosis occurred through the phosphoinositide 3 kinase (PI3K)/Akt pathway by targeting of phosphatase and tensin homolog deleted on chromosome ten (PTEN). Higher miR-181c overexpression correlated with lower neurological severity scores, indicating better recovery of neurological function. In conclusion, miR-181c affects the prognosis of intracerebral hemorrhage by regulating apoptosis, and these effects might be directly mediated and regulated by targeting of the PTEN\PI3K/Akt pathway and Bcl-2/Bax ratio. Furthermore, these results indicated that miR-181c played a neuroprotective role in intracerebral hemorrhage by regulating apoptosis of nerve cells, thus providing a potential target for the prevention and treatment of intracerebral hemorrhage. Testing of human serum was authorized by the Ethics Committee of China Medical University (No. 2012-38-1) on February 20, 2012. The protocol was registered with the Chinese Clinical Trial Registry (Registration No. ChiCTR-COC-17013559). The animal study was approved by the Institutional Animal Care and Use Committee of China Medical University (approval No. 2017008) on March 8, 2017.

miR‑222 regulates brain injury and inflammation following intracerebral hemorrhage by targeting ITGB8

Intracerebral hemorrhage (ICH) is a disease associated with high mortality and morbidity. MicroRNAs (miRNAs) have been reported to be associated with the pathogenesis of numerous cerebrovascular diseases, including ICH. miR-222 has been revealed to play important roles in various physiological and pathological processes in cardiovascular diseases. However, its role in ICH remains largely unknown. The aim of the present study was to evaluate the potential effect of miR-222 on brain injury in ICH. The results revealed that the expression of miR-222 was significantly increased in ICH, and downregulation of miR-222 significantly reduced erythrocyte lysate-induced cell apoptosis by decreasing the levels of cleaved caspase-3, cleaved caspase-9 and Bax and increasing the level of Bcl-2. In addition, downregulation of miR-222 suppressed the inflammatory responses in erythrocyte lysate-induced microglia, and inhibited inflammation, brain water content and improved neurological functions in ICH mice. Mechanistically, integrin subunit β8 (ITGB8) was identified as a direct target of negative regulation by miR-222 in microglia cells, and up-regulation of ITGB8 led to the attenuation of inflammation and apoptosis. Collectively, the present findings indicated that miR-222 was a crucial regulator of inflammation via targeting of ITGB8, and represented a promising therapeutic strategy for ICH.

Pharmacokinetics and Acute Toxicity of a Histone Deacetylase Inhibitor, Scriptaid, and its Neuroprotective Effects in Mice After Intracranial Hemorrhage

BACKGROUND & OBJECTIVE

The pharmacokinetics and acute toxicity of a histone deacetylase inhibitor, Scriptaid, was unknown in the mouse. The aim of this study was to determine the pharmacokinetics, acute toxicity, and tissue distribution of Scriptaid, a new histone deacetylase inhibitor, in mice, and its neuroprotective efficacy in a mouse intracranial hemorrhage (ICH) model.

METHODS

The pharmacokinetics, acute toxicity, and tissue distribution were determined in C57BL/6 male and female mice after the intraperitoneal administration of a single dose. Behavioral tests, as well as investigations of brain atrophy and white matter injury, were used to evaluate the neuroprotective effect of Scriptaid after ICH. Western blotting was used to investigate if Scriptaid could offer antiinflammatory benefits after ICH.

RESULTS

No significant differences were observed in body weight or brain histopathology between the group that received Scriptaid at 50 mg/kg and the group that received dimethyl sulfoxide (control). The pharmacokinetics of Scriptaid in mice was nonlinear, and it was cleared rapidly at low doses and slowly at higher doses. Consistent with the pharmacokinetic data, Scriptaid was found to distribute in several tissues, including the spleen and kidneys. In the ICH model, we found that Scriptaid could reduce neurological deficits, brain atrophy, and white matter injury in a dose-dependent manner. Western blotting results demonstrated that Scriptaid could decrease the expression of pro-inflammatory cytokines IL1β and TNFα, as well as iNOS, after ICH.

CONCLUSION

These findings indicate that Scriptaid is safe and can alleviate brain injury after ICH, thereby providing a foundation for the pharmacological action of Scriptaid in the treatment of brain injury after ICH.

Comparison of perihematomal perfusion in deep and lobar intracerebral hemorrhage

PURPOSE

Hypoperfusion in the perihematomal rim is common in acute intracerebral hemorrhage (ICH) but its determinants remain incompletely characterized. Despite known biological differences between deep and lobar ICH, the association between ICH location and cerebral perfusion has not been investigated. We tested the hypothesis that perihematomal perfusion differs between deep and lobar ICH.

METHODS

Prospectively collected cohort of subjects with primary spontaneous ICH undergoing CT perfusion on admission. Cerebral blood flow (CBF), blood volume (CBV), and mean transit time (MTT) were measured in the manually outlined perihematomal low-density area. The association between perihematomal perfusion and ICH location was explored with multivariable linear regression.

RESULTS

A total of 155 patients were enrolled (59 with a lobar bleeding). In univariate analysis, median perihematomal CBF and CBV were lower in lobar ICH compared with deep ICH (23.8 vs 33.4 mL/100 g/min, p = 0.001 and 1.7 vs 2.3 mL/100 g, p = 0.001, respectively). Lobar ICH location remained inversely associated with CBF (β = - 0.17, p = 0.038) and CBV (β = - 0.19, p = 0.023) after adjustment for confounders in linear regression.

CONCLUSION

Lobar ICH location is inversely related with perihematomal CBF and CBV. Further studies are needed to confirm this association and define the underlying biological mechanisms.

Apelin-13/APJ system attenuates early brain injury via suppression of endoplasmic reticulum stress-associated TXNIP/NLRP3 inflammasome activation and oxidative stress in a AMPK-dependent manner after subarachnoid hemorrhage in rats

Background

Neuroinflammation and oxidative stress play important roles in early brain injury following subarachnoid hemorrhage (SAH). This study is the first to show that activation of apelin receptor (APJ) by apelin-13 could reduce endoplasmic reticulum (ER)-stress-associated inflammation and oxidative stress after SAH.

Methods

Apelin-13, apelin siRNA, APJ siRNA, and adenosine monophosphate-activated protein kinase (AMPK) inhibitor-dorsomorphin were used to investigate if the activation of APJ could provide neuroprotective effects after SAH. Brain water content, neurological functions, blood-brain barrier (BBB) integrity, and inflammatory molecules were evaluated at 24 h after SAH. Western blotting and immunofluorescence staining were applied to assess the expression of target proteins.

Results

The results showed that endogenous apelin, APJ, and p-AMPK levels were significantly increased and peaked in the brain 24 h after SAH. In addition, administration of exogenous apelin-13 significantly alleviated neurological functions, attenuated brain edema, preserved BBB integrity, and also improved long-term spatial learning and memory abilities after SAH. The underlying mechanism of the neuroprotective effects of apelin-13 is that it suppresses microglia activation, prevents ER stress from overactivation, and reduces the levels of thioredoxin-interacting protein (TXNIP), NOD-like receptor pyrin domain-containing 3 protein (NLRP3), Bip, cleaved caspase-1, IL-1β, TNFα, myeloperoxidase (MPO), and reactive oxygen species (ROS). Furthermore, the use of APJ siRNA and dorsomorphin abolished the neuroprotective effects of apelin-13 on neuroinflammation and oxidative stress.

Conclusions

Exogenous apelin-13 binding to APJ attenuates early brain injury by reducing ER stress-mediated oxidative stress and neuroinflammation, which is at least partly mediated by the AMPK/TXNIP/NLRP3 signaling pathway.

Loss of Endothelial Laminin α5 Exacerbates Hemorrhagic Brain Injury

Endothelial cells make laminin-411 and laminin-511. Although laminin-411 is well studied, the role of laminin-511 remains largely unknown due to the embryonic lethality of lama5-/- mutants. In this study, we generated endothelium-specific lama5 conditional knockout (α5-TKO) mice and investigated the biological functions of endothelial lama5 in blood-brain barrier (BBB) maintenance under homeostatic conditions and the pathogenesis of intracerebral hemorrhage (ICH). First, the BBB integrity of α5-TKO mice was measured under homeostatic conditions. Next, ICH was induced in α5-TKO mice and their littermate controls using the collagenase model. Various parameters, including injury volume, neuronal death, neurological score, brain edema, BBB integrity, inflammatory cell infiltration, and gliosis, were examined at various time points after injury. Under homeostatic conditions, comparable levels of IgG or exogenous tracers were detected in α5-TKO and control mice. Additionally, no differences in tight junction expression, pericyte coverage, and astrocyte polarity were found in these mice. After ICH, α5-TKO mice displayed enlarged injury volume, increased neuronal death, elevated BBB permeability, exacerbated infiltration of inflammatory cells (leukocytes, neutrophils, and mononuclear cells), aggravated gliosis, unchanged brain edema, and worse neurological function, compared to the controls. These findings suggest that endothelial lama5 is dispensable for BBB maintenance under homeostatic conditions but plays a beneficial role in ICH.

Perihematomal Edema After Intracerebral Hemorrhage in Patients With Active Malignancy

Background and Purpose- Patients with active malignancy are at risk for intracerebral hemorrhage (ICH). We aimed to characterize perihematomal edema (PHE) and hematoma volumes after spontaneous nontraumatic ICH in patients with cancer without central nervous system involvement. Methods- Patients with active malignancy who developed ICH were retrospectively identified through automated searches of institutional databases. Control patients were identified with ICH and without active cancer. Demographic and cancer-specific data were obtained by chart review. Hematoma and PHE volumes were determined using semiautomated methodology. Univariate and multivariate linear regression models were created to assess which variables were associated with hematoma and PHE expansion. Results- Patients with cancer (N=80) and controls (N=136) had similar demographics (all P>0.20), although hypertension was more prevalent among controls (P=0.004). Most patients with cancer had received recent chemotherapy (n=45, 56%) and had recurrence of malignancy (n=43, 54%). Patients with cancer were thrombocytopenic (median platelet count 90 000 [interquartile range, 17 500-211 500]), and most had undergone blood product transfusion (n=41, 51%), predominantly platelets (n=38, 48%). Thirty-day mortality was 36% (n=29). Patients with cancer had significantly increased PHE volumes (23.67 versus 8.61 mL; P=1.88×10^-9) and PHE-to-ICH volume ratios (2.26 versus 0.99; P=2.20×10^-16). In multivariate analyses, variables associated with PHE growth among patients with cancer were ICH volume (β=1.29 [95% CI, 1.58-1.30] P=1.30×10^-5) and platelet transfusion (β=15.67 [95% CI, 3.61-27.74] P=0.014). Variables associated with 30-day mortality were ICH volume (odds ratio, 1.06 [95% CI, 1.03-1.10] P=6.76×10^-5), PHE volume (odds ratio, 1.07 [95% CI, 1.04-1.09] P=7.40×10^-6), PHE growth (odds ratio, 1.05 [95% CI, 1.01-1.10] P=0.01), and platelet transfusion (odds ratio, 1.48 [95% CI, 1.22-1.79] P=0.0001). Conclusions- Patients with active cancer who develop ICH have increased PHE volumes. PHE growth was independent of thrombocytopenia but associated with blood product transfusion. Thirty-day mortality was associated with PHE and ICH volumes and blood product transfusion.

Association Between Eosinophilic Leukocyte Count and Hematoma Expansion in Acute Spontaneous Intracerebral Hemorrhage

Background/Objective: Hematoma expansion (HE) predicts poor outcome and is an appealing treatment target in spontaneous intracerebral hemorrhage (ICH). Clinical evidence has shown an association of HE with peripheral white blood cells (WBC) count, but the individual contributions of leukocyte subtypes between literatures are described inconsistently. Our aim was to determine the relationship between admission absolute and differential leukocyte counts and HE by using different growth definitions.

Methods: We analyzed spontaneous ICH patients who underwent baseline cranial computed tomography and blood sampling within 6 h of stroke onset in our institution between September 2013 and August 2018. Hematoma volume was calculated using a semiautomated 3-dimensional reconstruction algorithm. According to commonly used absolute or relative growth definitions (>6 mL, >12.5 mL, or >33%), we defined 5 types of HE. A propensity score-matching analysis was performed to evaluate the influence of complete blood count components on HE across the various growth definitions. The receiver operating characteristic analysis assessed the predictive ability of leukocyte counts for HE.

Results: A total of 1,066 patients were included, of whom 11–21% met the 5 HE definitions. After propensity score-matching, except using the definition of >12.5 mL growth or its combination with >33% growth, both WBC and neutrophil count were independently associated with reduced risk of HE (odds ratio [OR] for 10³ cells increase; OR, 0.86–0.99; all p < 0.05) after adjusting confounders in multivariate analyses. However, monocyte count was correlated with increased risk of HE under the usage of >12.5 mL expansion definition only (OR, 1.43; p = 0.024). There was no association between lymphocyte count and HE (all p > 0.05). Regardless of the growth definition, admission eosinophil count was directly associated with the risk of HE (OR, 6.92–31.60; all p < 0.05), and was the best predictive subtype with area under the curve 0.64, sensitivity 69.5%, and specificity 58.9% at the optimal cut-off value of 45 cells/μL.

Conclusions: Growth definition affects the relationship of HE with leukocyte subtypes counting. Eosinophil count robustly predicts HE, and may be a surrogate when using an inflammatory marker to help select acute ICH patients with high expansion risk for hemostasis treatment in clinical trial and practice.

Modified behavioural tests to detect white matter injury- induced motor deficits after intracerebral haemorrhage in mice

Motor function deficit induced by white matter injury (WMI) is one of the most severe complications of intracerebral haemorrhage (ICH). The degree of WMI is closely related to the prognosis of patients after ICH. However, the current behavioural assessment of motor function used in the ICH mouse model is mainly based on that for ischaemic stroke and lacks the behavioural methods that accurately respond to WMI. Here, a series of easy-to-implement behavioural tests were performed to detect motor deficits in mice after ICH. The results showed that the grip strength test and the modified pole test not only can better distinguish the degree of motor dysfunction between different volumes of blood ICH models than the Basso Mouse Scale and the beam walking test but can also accurately reflect the severity of WMI characterized by demyelination, axonal swelling and the latency of motor-evoked potential delay induced by ICH. In addition, after ICH, the results of grip tests and modified pole tests, rather than the Basso Mouse Scale and the beam walking test, were worse than those observed after intraventricular haemorrhage (IVH), which was used as a model of brain haemorrhage in non-white matter areas. These results indicate that the grip strength test and the modified pole test have advantages in detecting the degree of motor deficit induced by white matter injury after ICH in mice.

Gastrodin Attenuates Neuronal Apoptosis and Neurological Deficits after Experimental Intracerebral Hemorrhage

OBJECTIVE

Gastrodin, a glucoside of gastrodigenin, inhibits cerebral oxidant stress and apoptosis in multiple central nervous system injury, but its effect in intracerebral hemorrhage (ICH) remains unclear. This study investigated the effect of gastrodin on neuronal apoptosis and neurological deficits in rat ICH model.

METHODS

In vitro experiments were performed using hematoma lysate-induced cell damage model in primary cortical neurons. Rat ICH model was produced by a caudatum injection of collagenase. Gastrodin was intraperitoneal injected after 2 hours following ICH. Cell viability, brain water content, neurological score, western blot, and immunofluorescence experiments were performed.

RESULTS

Gastrodin significantly decreased hematoma lysate-induced reduction of cell viability and cell apoptosis in primary cortical neurons. Gastrodin significantly improved brain edema and neurological deficits post-ICH. Moreover, gastrodin administration significantly reduced levels of ROS, 8-OHDG, 3-Nitrotyrosine and MDA, while increased GSH-Px and SOD activity, and stimulated the upregulation of Keap1, Nrf2, and HO-1 signaling at 72 hours post-ICH. Furthermore, gastrodin significantly increased Bcl-2 expression, while reduced level of Bax, active caspase-3 and active caspase-9, also reduced the number of active caspase-3 or TUNEL positive neurons at 72 hours post-ICH.

CONCLUSION

These results suggest that gastrodin is neuroprotective after ICH and the mechanism may be associated with the inhibition of oxidative stress and neuronal apoptosis.

Statins for neuroprotection in spontaneous intracerebral hemorrhage

Statins, a common drug class for treatment of dyslipidemia, may be neuroprotective for spontaneous intracerebral hemorrhage (ICH) by targeting secondary brain injury pathways in the surrounding brain parenchyma. Statin-mediated neuroprotection may stem from downregulation of mevalonate and its derivatives, targeting key cell signaling pathways that control proliferation, adhesion, migration, cytokine production, and reactive oxygen species generation. Preclinical studies have consistently demonstrated the neuroprotective and recovery enhancement effects of statins, including improved neurologic function, reduced cerebral edema, increased angiogenesis and neurogenesis, accelerated hematoma clearance, and decreased inflammatory cell infiltration. Retrospective clinical studies have reported reduced perihematomal edema, lower mortality rates, and improved functional outcomes in patients who were taking statins before ICH. Several clinical studies have also observed lower mortality rates and improved functional outcomes in patients who were continued or initiated on statins after ICH. Subgroup analysis of a previous randomized trial has raised concerns of a potentially elevated risk of recurrent ICH in patients with previous hemorrhagic stroke who are administered statins. However, most statin trials failed to show an association between statin use and increased hemorrhagic stroke risk. Variable statin dosing, statin use in the pre-ICH setting, and selection biases have limited rigorous investigation of the effects of statins on post-ICH outcomes. Future prospective trials are needed to investigate the association between statin use and outcomes in ICH.

Intracerebral Hemorrhage: Blood Components and Neurotoxicity

Intracerebral hemorrhage (ICH) is a subtype of stroke which is associated with the highest mortality and morbidity rates of all strokes. Although it is a major public health problem, there is no effective treatment for ICH. As a consequence of ICH, various blood components accumulate in the brain parenchyma and are responsible for much of the secondary brain damage and ICH-induced neurological deficits. Therefore, the strategies that could attenuate the blood component-induced neurotoxicity and improve hematoma resolution are highly needed. The present article provides an overview of blood-induced brain injury after ICH and emphasizes the need to conduct further studies elucidating the mechanisms of hematoma resolution after ICH.

Role of cerebral glutamate in post-stroke epileptogenesis

Stroke is one of the most important causes of acquired epilepsy in the adult population. While factors such as cortical involvement and haemorrhage have been associated with increased seizure risk, the mechanisms underlying the development of epilepsy after stroke remain unclear. One hypothesised mechanism is an excitotoxic effect of abnormal glutamate release following a stroke. Cerebral extracellular glutamate levels are known to rise in the setting of acute stroke, and numerous studies have implicated glutamate in the pathogenesis of seizures and epilepsy, both through direct measurement of glutamate from the epileptic brain and by analysis of receptors and transporters central to glutamate homeostasis. While experimental evidence suggests the cellular injury induced by glutamate exposure may lead to development of an epileptic phenotype, there is little direct data linking the rise in glutamate during stroke with the later development of epilepsy. Clinical research in this field has been hampered by the lack of non-invasive methods to measure cerebral glutamate. However, with the increasing availability of 7T MRI technology, Magnetic Resonance Spectroscopy is able to better resolve glutamate from other chemical species at this field strength, and Glutamate Chemical Exchange Saturation Transfer (GluCEST) imaging has been applied to localise epileptic foci in non-lesional focal epilepsy. This review outlines the evidence implicating a pivotal role for cerebral glutamate in the development of post-stroke epilepsy, and exploring the role of MRI in studying glutamate as a biomarker and therefore its suitability as a molecular target for anti-epileptogenic therapies. We hypothesise that the rise in glutamate levels in the setting of acute stroke is a clinically relevant biomarker for the development of post-stroke epilepsy.

Over-Activated Proteasome Mediates Neuroinflammation on Acute Intracerebral Hemorrhage in Rats

Background: Neuroinflammation is a hallmark in intracerebral hemorrhage (ICH) that induces secondary brain injury, leading to neuronal cell death. ER stress-triggered apoptosis and proteostasis disruption caused neuroinflammation to play an important role in various neurological disorders. The consequences of ER stress and proteostasis disruption have rarely been studied during the course of ICH development. Methods: ICH was induced by collagenase VII-S intrastriatal infusion. Animals were sacrificed at 0, 3, 6, 24, and 72 h post-ICH. Rats were determined for body weight changes, hematoma volume, and neurological deficits. Brain tissues were harvested for molecular signaling analysis either for ELISA, immunoblotting, immunoprecipitation, RT-qPCR, protein aggregation, or for histological examination. A non-selective proteasome inhibitor, MG132, was administered into the right striatum three hours prior to ICH induction. Results: ICH-induced acute proteasome over-activation caused the early degradation of the endoplasmic reticulum (ER) chaperone GRP78 and IκB protein. These exacerbations were accompanied by the elevation of pro-apoptotic CCAAT-enhancer-binding protein homologous protein (CHOP) and pro-inflammatory cytokines expression via nuclear factor-kappa B (NF-κB) signal activation. Pre-treatment with proteasome inhibitor MG132 significantly ameliorated the ICH-induced ER stress/proteostasis disruption, pro-inflammatory cytokines, neuronal cells apoptosis, and neurological deficits. Conclusions: ICH induced rapid proteasome over-activation, leading to an exaggeration of the ER stress/proteostasis disruption, and neuroinflammation might be a critical event in acute ICH pathology.