High serum levels of growth factors are associated with good outcome in intracerebral hemorrhage

Gene expression changes implicate specific peripheral immune responses to Deep and Lobar Intracerebral Hemorrhages in humans

The peripheral immune system response to Intracerebral Hemorrhage (ICH) may differ with ICH in different brain locations. Thus, we investigated peripheral blood mRNA expression of Deep ICH, Lobar ICH, and vascular risk factor-matched control subjects (n = 59). Deep ICH subjects usually had hypertension. Some Lobar ICH subjects had cerebral amyloid angiopathy (CAA). Genes and gene networks in Deep ICH and Lobar ICH were compared to controls. We found 774 differentially expressed genes (DEGs) and 2 co-expressed gene modules associated with Deep ICH, and 441 DEGs and 5 modules associated with Lobar ICH. Pathway enrichment showed some common immune/inflammatory responses between locations including Autophagy, T Cell Receptor, Inflammasome, and Neuroinflammation Signaling. Th2, Interferon, GP6, and BEX2 Signaling were unique to Deep ICH. Necroptosis Signaling, Protein Ubiquitination, Amyloid Processing, and various RNA Processing terms were unique to Lobar ICH. Finding amyloid processing pathways in blood of Lobar ICH patients suggests peripheral immune cells may participate in processes leading to perivascular/vascular amyloid in CAA vessels and/or are involved in its removal. This study identifies distinct peripheral blood transcriptome architectures in Deep and Lobar ICH, emphasizes the need for considering location in ICH studies/clinical trials, and presents potential location-specific treatment targets.

Combining modified Graeb score and intracerebral hemorrhage score to predict poor outcome in patients with spontaneous intracerebral hemorrhage undergoing surgical treatment

Objective

Spontaneous intracerebral hemorrhage (sICH) is a frequently encountered neurosurgical disease. The purpose of this study was to evaluate the relationship between modified Graeb Score (mGS) at admission and clinical outcomes of sICH and to investigate whether the combination of ICH score could improve the accuracy of outcome prediction.

Methods

We retrospectively reviewed the medical records of 511 patients who underwent surgery for sICH between January 2017 and June 2021. Patient outcome was evaluated by the Glasgow Outcome Scale (GOS) score at 3 months following sICH, where a GOS score of 1–3 was defined as a poor prognosis. Univariate and multivariate logistic regression analyses were conducted to determine risk factors for unfavorable clinical outcomes. Receiver operating characteristic (ROC) curve analysis was performed to detect the optimal cutoff value of mGS for predicting clinical outcomes. An ICH score combining mGS was created, and the performance of the ICH score combining mGS was assessed for discriminative ability.

Results

Multivariate analysis demonstrated that a higher mGS score was an independent predictor for poor prognosis (odds ratio [OR] 1.207, 95% confidence interval [CI], 1.130–1.290, p < 0.001). In ROC analysis, an optimal cutoff value of mGS to predict the clinical outcome at 3 months after sICH was 11 (p < 0.001). An increasing ICH-mGS score was associated with increased poor functional outcome. Combining ICH score with mGS resulted in an area under the curve (AUC) of 0.790, p < 0.001.

Conclusion

mGS was an independent risk factor for poor outcome and it had an additive predictive value for outcome in patients with sICH. Compared with the ICH score and mGS alone, the ICH score combined with mGS revealed a significantly higher discriminative ability for predicting postoperative outcome.

Association of Changed Serum Brain Biomarkers With Perihematomal Edema and Early Clinical Outcome in Primary ICH Patients

BACKGROUND

Perihematomal edema (PHE) following primary intracranial hemorrhages (ICHs) affects the patient outcome. Also, serum biomarkers such as S100 calcium-binding protein B (S100B) and glial fibrillary acidic protein (GFAP) have been associated with ICHs outcome. We aimed to investigate the association between these biomarkers and PHE in ICH patients.

METHODS

In this cross-sectional study, patients with primary ICH between January 2020 and August 2020 were evaluated. All participants underwent spiral brain computed tomography scans upon admission, and 48 to 72 hours later and quantification of initial hematoma volume was performed. Serum level of matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEGF), GFAP, and S100B on admission were measured by enzyme-linked immunosorbent assays. Acute clinical outcome was assessed by the modified-Rankin scale, National Institute of Health Stroke Scale (NIHSS), and ICH score.

RESULTS

Thirty-seven ICH patients (21 patients with a favorable outcome and 16 unfavorable) were studied. Compared with survival patients, nonsurvivor patients showed a higher serum level of MMP-9, VEGF, GFAP, and S100B ( P <0.05). Scores of absolute PHE, edema expansion distance, and PHE growth rate in the nonsurvivor group were higher than the survivors ( P <0.001). The regression model revealed that MMP-9, VEGF, ICH score, and hematoma volume were associated with the PHE growth rate. S100B and ICH score were associated with edema expansion distance.

CONCLUSIONS

Our data showed that the serum level of molecular biomarkers was associated with higher PHE volume and PHE scores were higher in nonsurvival patients, suggesting it may have a pathogenic role in developing PHE after ICH.

Prognostic molecular markers for motor recovery in acute hemorrhagic stroke: A systematic review

BACKGROUND AND AIMS

Molecular biomarkers are associated with poor prognosis in ischemic stroke individuals. However, it might not be generalizable to post-acute hemorrhagic stroke since the underlying mechanisms of this brain damage differ from those found in ischemic stroke. The main purpose of this review was to synthesize the potential predictive molecular biomarkers for motor recovery following acute hemorrhagic stroke.

MATERIALS AND METHODS

An electronic search was conducted by 2 independent reviewers in the following databases: PubMed (Medline), EMBASE, Web of Science, and CINAHL. We included studies that addressed the following: collected blood, urine, or cerebrospinal fluid samples within 72 h after hemorrhagic stroke and that reported the prognostic association with functional motor recovery for each molecular biomarker. Screening of titles, abstracts, and full texts and data extraction were undertaken independently by pairs of reviewers.

RESULTS

Twelve thousand, five hundred and sixty-four studies were identified and 218 were considered eligible. Finally, we included 70 studies, with 96 biomarkers analyzed, of which 61 were considered as independent prognostic biomarkers, and 10 presented controversial results.

CONCLUSION

This systematic review shows that motor functional recovery can be predicted by 61 independent prognostic molecular biomarkers assessed in the acute phase after a hemorrhagic stroke.

Expression and methylation status of vascular endothelial growth factor and thrombospondin-1 genes in congenital factor XIII-deficient patients with intracranial hemorrhage

Congenital factor XIII (FXIII) deficiency is one of the rarest bleeding disorders, with an incidence of one per 2 million persons. Intracranial hemorrhage (ICH), a major cause of mortality in FXIII deficiency, is reported to be associated with vascular endothelial growth factor (VEGF) and thrombospondin-1 (TSP-1). Therefore, we investigated the association of VEGF and TSP-1 expression and methylation patterns with ICH in congenital FXIII deficiency patients. This study was conducted on 40 participants with FXIII, 20 of whom experienced ICH (cases), and 20 who did not (controls). Methylation pattern, gene expression, and plasma protein level were assessed using bisulfite sequencing PCR, quantitative real-time PCR, and ELISA. We found a partially methylated pattern for both VEGF and TSP-1 (P > 0.05). VEGF mRNA levels of the case group were significantly higher than those of the control group (P < 0.05), whereas TSP-1 mRNA levels did not show significant upregulation (P > 0.05). Plasma VEGF and TSP-1 concentrations in the case group were higher, but not statistically significant (P > 0.05). Our findings showed no obvious correlation between VEGF or TSP-1 methylation patterns and expression, suggesting that their expression in FXIII deficiency may not solely be controlled by gene methylation.

Circulating granulocyte colony-stimulating factor and functional outcome after ischemic stroke: an observational study

Objectives: While granulocyte colony-stimulating factor (G-CSF) has shown beneficial effects in experimental ischemic stroke (IS), these effects have not been reproduced clinically. Small-to-medium-sized observational studies have reported varying associations for G-CSF with stroke severity and post-stroke functional outcome, prompting their investigation in a larger study.Methods: Endogenous serum G-CSF (S-GCSF) was measured in the acute phase and after 3 months in patients with IS (N = 435; 36% females; mean age, 57 years) from the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS). Stroke severity was scored according to the National Institutes of Health Stroke Scale (NIHSS), and the modified Rankin Scale (mRS) assessed functional outcomes at 3-month and 2-year post-stroke. Correlation and logistic regression analyses with confounder adjustments assessed the relationships.Results: The acute S-GCSF level was 23% higher than at 3-month post-stroke (p < 0.001). Acute G-CSF correlated weakly with stroke severity quintiles (r = 0.12, p = 0.013) and with high-sensitivity C-reactive protein (r = 0.29, p < 0.001). The association between S-GCSF (as quintiles, q) and poor functional outcome at 3 months (mRS 3-6; S-GCSF-q5 vs. S-GCSF-q1, age- and sex-adjusted odds ratio: 4.27, 95% confidence interval: 1.82-9.99; p = 0.001) withstood adjustment for cardiovascular risk factors and stroke subtype, but not additional correction for stroke severity. Post-stroke changes in S-GSCF and absolute 3-month S-GCSF were not associated with 3-month or 2-year functional outcomes.Discussion: Early post-stroke S-GCSF is increased in severe IS and associated with 3-month poor functional outcomes. The change in S-GCSF and the 3-month S-GCSF appear to be less-important, and S-GCSF likely reflects inflammation in large infarctions.

Inflammatory Markers in Severity of Intracerebral Hemorrhage II: A Follow Up Study

Introduction

Spontaneous intracerebral hemorrhage (ICH) results in significant morbidity and mortality. The pathogenesis of brain injury after ICH is thought to be due to mechanical damage followed by ischemic, cytotoxic, and inflammatory changes in the underlying and surrounding tissue. Various inflammatory and non-inflammatory biomarkers have been studied as predictors and potential therapeutic targets for intracerebral hemorrhage. Our prior study showed an association with low vascular endothelial growth factor (VEGF) levels and increased mortality. This current study looks to expand on our prior results and will look at the relationship between tumor necrosis factor alpha (TNFα), C-reactive protein (CRP), VEGF, Homocysteine (Hcy), and CRP to albumin ratio (CAR) in predicting outcomes and severity in spontaneous intracerebral hemorrhage.

Methods

We conducted a retrospective chart review of patients with spontaneous intracerebral hemorrhage with TNFα, CRP, VEGF, Hcy levels drawn on admission. Albumin and CRP levels on admission were used to calculate CAR. Ninety-nine patients were included in the study. Primary outcomes included death, early neurologic decline (END), and hemorrhage size. Secondary outcomes included late neurologic decline (LND), Glasgow Coma Scale (GCS) on admission, GCS on discharge, ICH score, change in hemorrhage size, need for surgical intervention, and length of ICU stay.

Results

A total of 99 patients were included in this study, with 42% requiring surgical intervention and an overall mortality of 16%. Basal ganglia hemorrhage was seen in 41% of patients. Hcy and CAR were significantly correlated with ICH size in basal ganglia patients (r-=0.36, p=0.03; r=0.43, p=0.03, respectively). CAR was significantly correlated with ICH score (r=0.33, p=0.007874). Admission VEGF levels less than 45 pg/ml had 8.4-fold increase in mortality (odds ratio [OR] 8.4545, p=0.0488). Patients with TNFα levels greater than 1.40 pg/ml had a 4.1-fold increase in mortality (OR 4.1, p=0.04)

Conclusion

Our study demonstrated that low levels (<45 pg/ml) of VEGF were associated with an 8.4-fold increase in mortality, supporting the neuroprotective effect of this protein. Elevated Hcy and CAR levels were associated with an increase in hemorrhage size in patients with basal ganglia hemorrhages. TNFα levels greater than 1.40 pg/ml were associated with a 4.1-fold increase in mortality, and this together with CAR being correlated with increased hemorrhage size and ICH score further demonstrate the inflammatory consequences after intracerebral hemorrhage. Future studies directed at lowering CRP, TNFα, and Hcy and/or increasing VEGF in intracerebral hemorrhage patients are needed and may be beneficial.

Different changes in granulocyte-colony stimulating factor and its correlation with inflammatory biomarkers in patients after traumatic brain injury

OBJECTIVE

This study analyzed changes in granulocyte-colony stimulating factor (G-CSF) and its correlation with leukocyte and neutrophil counts in patients after traumatic brain injury (TBI).

METHODS

Sixty TBI patients were included retrospectively. The serum levels of G-CSF, tumor necrosis factor-α (TNF-α), and peripheral leukocyte and neutrophil counts at different time points were measured and analyzed, and the 6-month functional outcomes were monitored.

RESULTS

The levels of G-CSF in mild and moderate TBI groups were higher than the control at the first three time points. G-CSF in the severe TBI group increased slowly and peaked at day 7, and was only significantly different from the control at day 7 and 14. The leukocyte and neutrophil counts of the mild group gradually decreased, but a second increase after day 4 was observed in the severe group. The cell counts were higher in the severe group compared to other groups. A positive correlation between G-CSF and leukocyte and neutrophil counts was observed in the severe group at day 1. G-CSF positively correlated with TNF-α in the severe group at day 4 and 7. In severe patients with a good outcome, G-CSF level at day 7 was significantly higher than those with a poor outcome.

CONCLUSION

The G-CSF levels in the severe TBI group exhibited a different pattern from those in the mild and moderate TBI groups, and these levels positively correlated with inflammatory biomarkers. Higher G-CSF levels in severe TBI at day 7 indicated a good outcome at 6 months.

The Stroke-Induced Blood-Brain Barrier Disruption: Current Progress of Inspection Technique, Mechanism, and Therapeutic Target

Stroke is one of the leading causes of mortality and morbidity worldwide. The blood-brain barrier (BBB) is a characteristic structure of microvessel within the brain. Under normal physiological conditions, the BBB plays a role in the prevention of harmful substances entering into the brain parenchyma within the central nervous system. However, stroke stimuli induce the breakdown of BBB leading to the influx of cytotoxic substances, vasogenic brain edema, and hemorrhagic transformation. Therefore, BBB disruption is a major complication, which needs to be addressed in order to improve clinical outcomes in stroke. In this review, we first discuss the structure and function of the BBB. Next, we discuss the progress of the techniques utilized to study BBB breakdown in in-vitro and in-vivo studies, along with biomarkers and imaging techniques in clinical settings. Lastly, we highlight the mechanisms of stroke-induced neuroinflammation and apoptotic process of endothelial cells causing BBB breakdown, and the potential therapeutic targets to protect BBB integrity after stroke. Secondary products arising from stroke-induced tissue damage provide transformation of myeloid cells such as microglia and macrophages to pro-inflammatory phenotype followed by further BBB disruption via neuroinflammation and apoptosis of endothelial cells. In contrast, these myeloid cells are also polarized to anti-inflammatory phenotype, repairing compromised BBB. Therefore, therapeutic strategies to induce anti-inflammatory phenotypes of the myeloid cells may protect BBB in order to improve clinical outcomes of stroke patients.

Significance of Serum Angiopoietin-2 in Patients with Hemorrhage in Adult-Onset Moyamoya Disease

Background

Moyamoya disease (MMD) is a progressive occlusive cerebrovascular disease that is characterized by abnormal angiogenesis at the base of the brain. This pathological abnormal angiogenesis is susceptible to disturbances, including spontaneous hemorrhage and vasogenic edema. However, the underlying mechanisms of pathological angiogenesis and occurrence of hemorrhage are unclear. Angiopoietins play a fundamental role in the pathophysiology of central nervous system disorders in angiogenesis. This study was aimed at examining whether angiopoietins are associated with formation of abnormal collateral vessels and the occurrence of hemorrhage in adult-onset moyamoya disease (HMMD).

Methods

A total of 27 consecutive adult patients with HMMD were enrolled from June 2011 to May 2017. Serum levels of angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) were examined by enzyme-linked immunosorbent assay. Patients with HMMD were compared with those with spontaneous hemorrhage (controls) and nonhemorrhagic-onset MMD (NHMMD).

Results

Serum Ang-2 levels were significantly higher in patients with adult HMMD than in those with spontaneous hemorrhage and NHMMD. The ROC curve identified that a baseline serum Ang-2 level > 1230 ng/ml may be associated with adult HMMD with 88.39% sensitivity and 70.37% specificity (area under the curve (AUC), 0.89; 95% CI, 0.808-0.973; P < 0.001). Moreover, serum Ang-2 levels were significantly elevated in stages II, III, and IV. In subgroup analysis of a high and low degree of moyamoya vessels, serum Ang-2 levels were significantly higher in the high moyamoya vessel group than in the low moyamoya vessel group. Serum Ang-2 levels were also significantly higher in the low moyamoya vessel group compared with the control group. Serum Ang-1 levels were not significantly different among the groups.

Conclusion

Increased serum Ang-2 levels may contribute to pathological abnormal angiogenesis and/or to the instability of vascular structure and function, thus causing brain hemorrhage in adult HMMD.

Dual Roles of Astrocyte-Derived Factors in Regulation of Blood-Brain Barrier Function after Brain Damage

The blood-brain barrier (BBB) is a major functional barrier in the central nervous system (CNS), and inhibits the extravasation of intravascular contents and transports various essential nutrients between the blood and the brain. After brain damage by traumatic brain injury, cerebral ischemia and several other CNS disorders, the functions of the BBB are disrupted, resulting in severe secondary damage including brain edema and inflammatory injury. Therefore, BBB protection and recovery are considered novel therapeutic strategies for reducing brain damage. Emerging evidence suggests key roles of astrocyte-derived factors in BBB disruption and recovery after brain damage. The astrocyte-derived vascular permeability factors include vascular endothelial growth factors, matrix metalloproteinases, nitric oxide, glutamate and endothelin-1, which enhance BBB permeability leading to BBB disruption. By contrast, the astrocyte-derived protective factors include angiopoietin-1, sonic hedgehog, glial-derived neurotrophic factor, retinoic acid and insulin-like growth factor-1 and apolipoprotein E which attenuate BBB permeability resulting in recovery of BBB function. In this review, the roles of these astrocyte-derived factors in BBB function are summarized, and their significance as therapeutic targets for BBB protection and recovery after brain damage are discussed.

Programmed Cell Death after Intracerebral Hemorrhage

Background:

Intracerebral hemorrhage (ICH) accounts for up to 15% of all strokes and is characterized by high rates of mortality and morbidity. The post-ICH brain injury can be distinguished in 1) primary, which are caused by disrup-tion and mechanical deformation of brain tissue due to hematoma growth and 2) secondary, which are induced by microglia activation, mitochondrial dysfunction, neurotransmitter and inflammatory mediator release. Although these events typically lead to necrosis, the occurrence of programmed cell death has also been reported after ICH.

Methods:

We reviewed recent publications describing advance in pre- and clinic ICH research.

Results:

At present, treatment of ICH patients is based on oral anticoagulant reversal, management of blood pressure and other medical complications. Several pre-clinical studies showed promising results and demonstrated that anti-oxidative and anti-inflammatory treatments reduced neuronal cell death, however, to date, all of these attempts have failed in randomized controlled clinical trials. Yet, the time frame of administration may be crucial in translation from animal to clinical studies. Furthermore, the latest pre-clinical research points toward the existence of other, apoptosis-unrelated forms kinds of pro-grammed cell death.

Conclusion:

Our review summarizes current knowledge of pathways leading to programmed cell death after ICH in addition to data from clinical trials. Some of the pre-clinical results have not yet demonstrated clinical confirmation, however they sig-nificantly contribute to our understanding of post-ICH pathology and can contribute to development of new therapeutic ap-proaches, decreasing mortality and improving ICH patients’ quality of life.

Inflammatory Markers and Severity of Intracerebral Hemorrhage

Background and purpose

The pathogenesis of brain injury after intracerebral hemorrhage is thought to be due to mechanical damage followed by ischemic, cytotoxic, and inflammatory changes in the underlying and surrounding tissue.In recent years, there has been a greater research interest into the various inflammatory biomarkers and growth factors that are secreted during intracerebral hemorrhage. The biomarkers investigated in this study are tumor necrosis factor alpha (TNF alpha), C-reactive protein (CRP), homocysteine (Hcy), and vascular endothelial growth factor (VEGF). The aim of this study was to further investigate the effects of these biomarkers in predicting the acute severity outcome of intracerebral hemorrhage (ICH).

Methods

We conducted a retrospective chart review of patients with spontaneous ICH with TNF alpha, CRP, VEGF, and Hcy levels drawn on admission. Forty-two patients with spontaneous ICH with at least one of the above labs were included in the study. Primary outcomes included death, Glasgow Coma Scale (GCS) on admission, early neurologic decline (END), and hemorrhage size. Secondary outcomes included GCS on discharge, ICH score, functional outcome risk stratification scale of intracerebral hemorrhage (FUNC score), change in hemorrhage size, need for surgical intervention, and length of intensive care unit (ICU) stay.

Results

Forty-two patients with spontaneous intracerebral hemorrhage (ICH) were analyzed, 12 patients (28.5%) required surgical intervention, and four patients (9.5%) died. Only low VEGF serum values were found to predict mortality. TNF alpha, CRP, Hcy, and VEGF levels in our patients with ICH were not found to predict early neurologic decline and were not correlated with GCS on admission, initial hemorrhage size, change in hemorrhage size, need for surgical intervention, ICH score, FUNC score, midline shift, and length of ICU stay. CRP and Hcy were elevated in 58% and 31% of patients tested, respectively. GCS on admission and ICH score were significantly associated with mortality.

Conclusion

After careful statistical review of the data obtained from this patient population, only low VEGF values were found to be a significant predictor of mortality. However, elevated CRP and Hcy levels were associated with a non-significant trend in hemorrhage size and mortality suggesting that CRP and Hcy-lowering therapies may decrease hemorrhagic stroke risk and severity.

Dynamic changes in growth factor levels over a 7-day period predict the functional outcomes of traumatic brain injury

Traumatic brain injury (TBI) can result in poor functional outcomes and death, and overall outcomes are varied. Growth factors, such as angiopoietin-1 (Ang-1), vascular endothelial growth factor (VEGF), and granulocyte-colony stimulating factor (G-CSF), play important roles in the neurological functions. This study investigated the relationship between serum growth factor levels and long-term outcomes after TBI. Blood samples from 55 patients were collected at 1, 3 and 7 days after TBI. Blood samples from 39 healthy controls were collected as a control group. Serum Ang-1, G-CSF, and VEGF levels were measured using ELISA. Patients were monitored for 3 months using the Glasgow Outcome Scale-Extended (GOSE). Patients having a GOSE score of > 5 at 3 months were categorized as a good outcome, and patients with a GOSE score of 1–5 were categorized as a bad outcome. Our data demonstrated that TBI patients showed significantly increased growth factor levels within 7 days compared with healthy controls. Serum levels of Ang-1 at 1 and 7 days and G-CSF levels at 7 days were significantly higher in patients with good outcomes than in patients with poor outcomes. VEGF levels at 7 days were remarkably higher in patients with poor outcomes than in patients with good outcomes. Receiver operating characteristic analysis showed that the best cut-off points of serum growth factor levels at 7 days to predict functional outcome were 1,333 pg/mL for VEGF, 447.2 pg/mL for G-CSF, and 90.6 ng/mL for Ang-1. These data suggest that patients with elevated levels of serum Ang-1, G-CSF, and decreased VEGF levels had a better prognosis in the acute phase of TBI (within 7 days). This study was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR1800018251) on September 7, 2018.

The potential role of vascular endothelial growth factor as a new biomarker in severe intracerebral hemorrhage

BACKGROUND

We studied the association between high serum levels of vascular endothelial growth factor (VEGF) and clinical outcomes of intracerebral hemorrhage (ICH) patients.

METHODS

Patients were divided into group A (<20 mL), group B (20-30 mL), and group C (>30 mL) based on the bleeding amount. ICH patients were also categorized into the mild group, moderate group (16-30), and severe group (31-45) based on the National Institutes of Health Stroke Scale (NIHSS). The serum levels of VEGF in acute ICH patients detected at 24, 48, and 72 hours were obtained using ELISA kit, and then compared with control group. Main clinical outcomes were evaluated using the modified Rankin scale at 90 days.

RESULTS

The serum levels of VEGF were significantly higher than those in the control group. The serum levels of VEGF in group C were specifically higher compared with those in other two groups. The severe group exhibited higher levels of VEGF than the other two groups. NIHSS scores in patients with good outcomes were lower than those with poor outcomes. Besides, VEGF levels in patients with good outcomes were much higher than those in patients with poor outcomes. ROC results indicated that the optimal cut-off value of VEGF at 72 hours for predicting good outcomes was 111.17 pg/mL with 91.5 sensitivity, 98.7 specificity, and an AUC of 0.952 Our results showed that higher serum levels of VEGF were associated with process of ICH.

CONCLUSION

VEGF could be a new marker in ICH for severity.

Paracrine Mechanisms of Intravenous Bone Marrow-Derived Mononuclear Stem Cells in Chronic Ischemic Stroke

Background

The emerging role of stem cell technology and transplantation has helped scientists to study their potential role in neural repair and regeneration. The fate of stem cells is determined by their niche, consisting of surrounding cells and the secreted trophic growth factors. This interim report evaluates the safety, feasibility and efficacy (if any) of bone marrow-derived mononuclear stem cells (BM-MNC) in chronic ischemic stroke by studying the release of serum vascular endothelial growth factor (VEGF) and brain-derived neurotrophic growth factor (BDNF).

Methods

Twenty stroke patients and 20 age-matched healthy controls were recruited with the following inclusion criteria: 3 months to 1.5 years from the index event, Medical Research Council (MRC) grade of hand muscles of at least 2, Brunnstrom stage 2-5, conscious, and comprehendible. They were randomized to one group receiving autologous BM-MNC (mean 60-70 million) and to another group receiving saline infusion (placebo). All patients were administered a neuromotor rehabilitation regime for 8 weeks. Clinical assessments [Fugl Meyer scale (FM), modified Barthel index (mBI), MRC grade, Ashworth tone scale] were carried out and serum VEGF and BDNF levels were assessed at baseline and at 8 weeks.

Results

No serious adverse events were observed during the study. There was no statistically significant clinical improvement between the groups (FM: 95% CI 15.2-5.35, p = 0.25; mBI: 95% CI 14.3-4.5, p = 0.31). VEGF and BDNF expression was found to be greater in group 1 compared to group 2 (VEGF: 442.1 vs. 400.3 pg/ml, p = 0.67; BDNF: 21.3 vs. 19.5 ng/ml) without any statistically significant difference.

Conclusion

Autologous mononuclear stem cell infusion is safe and tolerable by chronic ischemic stroke patients. The released growth factors (VEGF and BDNF) in the microenvironment could be due to the paracrine hypothesis of stem cell niche and neurorehabilitation regime.

Blood Biomarkers for Evaluation of Perinatal Encephalopathy

Recent research in identification of brain injury after trauma shows many possible blood biomarkers that may help identify the fetus and neonate with encephalopathy. Traumatic brain injury shares many common features with perinatal hypoxic-ischemic encephalopathy. Trauma has a hypoxic component, and one of the 1st physiologic consequences of moderate-severe traumatic brain injury is apnea. Trauma and hypoxia-ischemia initiate an excitotoxic cascade and free radical injury followed by the inflammatory cascade, producing injury in neurons, glial cells and white matter. Increased excitatory amino acids, lipid peroxidation products, and alteration in microRNAs and inflammatory markers are common to both traumatic brain injury and perinatal encephalopathy. The blood-brain barrier is disrupted in both leading to egress of substances normally only found in the central nervous system. Brain exosomes may represent ideal biomarker containers, as RNA and protein transported within the vesicles are protected from enzymatic degradation. Evaluation of fetal or neonatal brain derived exosomes that cross the blood-brain barrier and circulate peripherally has been referred to as the "liquid brain biopsy." A multiplex of serum biomarkers could improve upon the current imprecise methods of identifying fetal and neonatal brain injury such as fetal heart rate abnormalities, meconium, cord gases at delivery, and Apgar scores. Quantitative biomarker measurements of perinatal brain injury and recovery could lead to operative delivery only in the presence of significant fetal risk, triage to appropriate therapy after birth and measure the effectiveness of treatment.

Increased Endothelial Progenitor Cell Levels are Associated with Good Outcome in Intracerebral Hemorrhage

Circulating endothelial progenitor cells (EPCs) play a role in the regeneration of damaged brain tissue. However, the relationship between circulating EPC levels and functional recovery in intracerebral hemorrhage (ICH) has not yet been tested. Therefore, our aim was to study the influence of circulating EPCs on the outcome of ICH. Forty-six patients with primary ICH (males, 71.7%; age, 72.7 ± 10.8 years) were prospectively included in the study within 12 hours of symptom onset. The main outcome variable was good functional outcome at 12 months (modified Rankin scale ≤2), considering residual volume at 6 months as a secondary variable. Circulating EPC (CD34⁺/CD133⁺/KDR⁺) levels were measured by flow cytometry from blood samples obtained at admission, 72 hours and day 7. Our results indicate that patients with good outcome show higher EPC numbers at 72 hours and day 7 (all p < 0.001). However, only EPC levels at day 7 were independently associated with good functional outcome at 12 months (OR, 1.15; CI95%, 1.01–1.35) after adjustment by age, baseline stroke severity and ICH volume. Moreover, EPC levels at day 7 were negatively correlated to residual volume (r = −0.525; p = 0.005). In conclusion, these findings suggest that EPCs may play a role in the functional recovery of ICH patients.

Assessing blood granulocyte colony-stimulating factor as a potential biomarker of acute traumatic brain injury in mice and humans

Previous work has found that serum G-CSF was acutely elevated in mice 24h but not one week after controlled cortical impact (CCI). The purpose of this study was to investigate whether blood G-CSF correlates with the elevated brain cytokines in mice after CCI and also if it correlates with traumatic brain injury (TBI) in humans. Here, we found in mice undergoing CCI, a procedure that induces direct injury to the brain, that serum G-CSF correlated directly or indirectly with several brain cytokines, indicating it is a useful marker for the neuroinflammation of TBI. A pilot study in humans (phase I, n=19) confirmed that plasma G-CSF is acutely elevated on day 1 (p<0.001) of TBI and has returned to baseline by one week. In a second human sample (phase II) (n=80), we found plasma G-CSF peaks about 12h after arriving in the emergency department (41.6+/-5.4 pg/ml). Aging was weakly associated (p<0.05) with a less robust elevation in serum G-CSF, but there was no difference with gender. ISS, a measure of total severity of injury, correlated with the degree of elevation in serum G-CSF (r=.419; p<0.05), but severity of head injury (via AIS) did not. The latter may have been because of the statistically narrow range of head injuries among our cases and the high number of cases diagnosed with closed head injury (a non-codable diagnosis). In conclusion, plasma G-CSF may be a useful biomarker of TBI, correlating with neuroinflammation in the animal model and in the human studies with time since injury and total severity of injury. As such, it may be useful in determining whether TBI has occurred within the last 24h.

High Angiopoietin-1 levels predict a good functional outcome within 72 h of an aneurysmal subarachnoid hemorrhage: A prospective study from a single center

BACKGROUND

The consequences of aneurysmal subarachnoid hemorrhage (aSAH) are lifelong and fatal. Angiopoietin-1 (Ang-1) and Angiopoietin-2 (Ang-2) play an important role in the regulation of vascular structure and function. Our study examined the association between angiopoietin levels and functional outcomes among aSAH patients.

METHODS

We enrolled 37 aSAH patients and 39 controls (matched on age and sex) at the Department of Neurosurgery in Tianjin Medical University General Hospital. Serum Ang-1, Ang-2, and Tie-2 levels were collected at 8, 24, and 72 hours post-hemorrhage. After a 3-month follow-up period, patient outcomes were evaluated using the Glasgow Outcome Score (GOS). Logistic regression examined the association between angiopoietin levels and outcomes (good [GOS: 4-5] vs. poor [GOS: 1-3]).

RESULTS

aSAH patients had higher levels of Ang-1 at 8 hours post-hemorrhage compared to controls. Among aSAH patients, Ang-1 levels at 8, 24, and 72 hours post-hemorrhage were higher among patients with a good outcome. Compared to patients with low Ang-1 levels, high Ang-1 levels at 72 hours post-hemorrhage were associated with a good outcome.

CONCLUSIONS

High Ang-1 levels were associated with a good functional outcome after aSAH. Abnormal angiopoietin levels may disrupt the blood-brain barrier and contribute to functional outcomes in aSAH patients.

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).

Emerging experimental therapies for intracerebral hemorrhage: targeting mechanisms of secondary brain injury

Intracerebral hemorrhage (ICH) is associated with a higher degree of morbidity and mortality than other stroke subtypes. Despite this burden, currently approved treatments have demonstrated limited efficacy. To date, therapeutic strategies have principally targeted hematoma expansion and resultant mass effect. However, secondary mechanisms of brain injury are believed to be critical effectors of cell death and neurological outcome following ICH. This article reviews the pathophysiology of secondary brain injury relevant to ICH, examines pertinent experimental models, and highlights emerging therapeutic strategies. Treatment paradigms discussed include thrombin inhibitors, deferoxamine, minocycline, statins, granulocyte-colony stimulating factors, and therapeutic hypothermia. Despite promising experimental and preliminary human data, further studies are warranted prior to effective clinical translation.

Protection of Vascular Endothelial Growth Factor to Brain Edema Following Intracerebral Hemorrhage and Its Involved Mechanisms: Effect of Aquaporin-4

Vascular endothelial growth factor (VEGF) has protective effects on many neurological diseases. However, whether VEGF acts on brain edema following intracerebral hemorrhage (ICH) is largely unknown. Our previous study has shown aquaporin-4 (AQP4) plays an important role in brain edema elimination following ICH. Meanwhile, there is close relationship between VEGF and AQP4. In this study, we aimed to test effects of VEGF on brain edema following ICH and examine whether they were AQP4 dependent. Recombinant human VEGF165 (rhVEGF165) was injected intracerebroventricularly 1 d after ICH induced by microinjecting autologous whole blood into striatum. We detected perihemotomal AQP4 protein expression, then examined the effects of rhVEGF165 on perihemotomal brain edema at 1 d, 3 d, and 7 d after injection in wild type (AQP4^+/+) and AQP4 knock-out (AQP4^−/−) mice. Furthermore, we assessed the possible signal transduction pathways activated by VEGF to regulate AQP4 expression via astrocyte cultures. We found perihemotomal AQP4 protein expression was highly increased by rhVEGF165. RhVEGF165 alleviated perihemotomal brain edema in AQP4^+/+ mice at each time point, but had no effect on AQP4^−/− mice. Perihemotomal EB extravasation was increased by rhVEGF165 in AQP4^−/− mice, but not AQP4^+/+ mice. RhVEGF165 reduced neurological deficits and increased Nissl’s staining cells surrounding hemotoma in both types of mice and these effects were related to AQP4. RhVEGF165 up-regulated phospharylation of C-Jun amino-terminal kinase (p-JNK) and extracellular signal-regulated kinase (p-ERK) and AQP4 protein in cultured astrocytes. The latter was inhibited by JNK and ERK inhibitors. In conclusion, VEGF reduces neurological deficits, brain edema, and neuronal death surrounding hemotoma but has no influence on BBB permeability. These effects are closely related to AQP4 up-regulation, possibly through activating JNK and ERK pathways. The current study may present new insights to treatment of brain edema following ICH.

Increased circulating endothelial progenitor cells in patients with haemorrhagic and ischaemic stroke: the role of endothelin-1

Ischaemic stroke induces endothelial progenitor cell (EPC) mobilisation from bone marrow into peripheral blood. Circulating EPCs play an important role in post-injury regeneration of vasculature, whereas endothelial cells (ECs) have been shown to reflect endothelial damage and may be responsible for increased Endothelin-1 (ET-1) expression. We investigated herein the association between numbers of circulating ECs and EPCs, the levels of soluble factors regulating their migration and function, and the clinical outcome in patients with haemorrhagic (HS) or ischaemic stroke (IS). Sixteen patients with HS and eighteen with IS were assessed during the first 24h, day 3, and day 7 after stroke and compared them with twenty-three control subjects. We found elevated EPC and EC concentrations using flow cytometry and increase in VEGF, SDF-1, HGF, and ET-1 plasma levels by ELISA in the HS patients, while ET-1 mRNA expression in peripheral blood cells was elevated in the IS patients. Significant correlations were observed between EPCs or ECs and Big ET-1 protein or mRNA levels in HS but not in the IS patients. We suggest that ET-1 may play a role in pathophysiology of stroke and subsequent EPC mobilisation; however, further studies aimed at the precise elucidation of this issue are required.

Serum biomarkers of spontaneous intracerebral hemorrhage induced secondary brain injury

Intracerebral hemorrhage (ICH) is a devastating form of stroke associated with a high rate of morbidity and mortality. It is now believed that much of this damage occurs in the subacute period following the initial insult via a cascade of complex pathophysiologic pathways that continues to be investigated. Increased levels of certain serum proteins have been identified as biomarkers that may reflect or directly participate in the inflammation, blood brain barrier disruption, endothelial dysfunction, and neuronal and glial toxicity that occur during this secondary period of cerebral injury. Some of these biomarkers have the potential to serve as therapeutic targets or surrogate endpoints for future research or clinical trials. Others may someday augment current clinical techniques in diagnosis, risk-stratification, prognostication, treatment decision and measurement of therapeutic efficacy. While much work remains to be done, biomarkers show significant potential to expand clinical options and improve clinical management, thereby reducing mortality and improving functional outcomes in ICH patients.

Angiopoietins as promising biomarkers and potential therapeutic targets in brain injury

Traumatic brain injury (TBI) and sub-arachnoid hemorrhage (SAH) are major causes of long-term disability, mortality, and enormous economic costs to society. The full spectrum of neurological damage created by TBI or SAH is not usually manifested at the time of injury, but evolves gradually over the course of hours to days (or weeks) following these injuries. Angiopoietins, important regulators of vascular structure and function, are hallmark indicators of vascular injury and may therefore represent promising targets in the treatment of SAH and TBI. In animal models and human tissues, normal intracerebral and pial vessels show strong expression of Angiopoietin-1 (Ang-1), but only minimal expression or presentation of Angiopoietin-2 (Ang-2). After several types of neurotrauma, the ratios of Ang-1 and Ang-2 expression in brain microvessel are disturbed and appear to contribute to the remarkable loss of blood-brain barrier (BBB) in these injuries. Angiopoietins levels, and perhaps more importantly, Angiopoietin ratios (1:2) may have novel and important diagnostic and prognostic uses in TBI and SAH brain injury. Ang-1/2 evaluation in plasma, serum and cerebrospinal fluid may provide new therapeutic modalities which can modify 'secondary' forms of brain injury after TBI and SAH.

Temporal profile of molecular signatures associated with circulating endothelial progenitor cells in human ischemic stroke

Endothelial progenitor cells (EPC) have been associated with good functional outcome in ischemic stroke. From preclinical studies, it has been reported that EPC proliferation is mediated by several molecular markers, including vascular endothelial growth factor (VEGF), stromal cell-derived factor-1α (SDF-1α), and the activity of matrix metalloproteinase-9 (MMP-9). Therefore, our aim was to study the role of these molecular factors in EPC proliferation in human ischemic stroke. Forty-eight patients with first episode of nonlacunar ischemic stroke were prospectively included in the study within 12 hr of symptom onset. EPC colonies were classified as early-outgrowth colony forming unit-endothelial cell (CFU-EC) and quantified at admission, at 24 and 72 hr, at day 7, and at 3 months. At the same time, serum levels of VEGF, SDF-1α, and active MMP-9 were measured by ELISA. The primary endpoint was EPC increment during the first week, which was defined as the difference in the number of CFU-EC between day 7 and admission. We found that VEGF (r = 0.782), SDF-1α (r = 0.828), and active MMP-9 (r = 0.740) levels at 24 hr from stroke onset showed a strong correlation with EPC increment. Similar results were found for VEGF levels at 72 hr (r = 0.839) and at day 7 (r = 0.602) as well as for active MMP-9 levels at 72 hr (r = 0.442) and at day 7 (r = 0.474). In the multivariate analyses, serum levels of VEGF at 72 hr (B: 0.074, P < 0.0001) and SDF-1α at 24 hr (B: 0.049, P = 0.008) were independent factors for EPC increment during the first week of evolution. These findings suggest that VEGF and SDF-1α may mediate EPC proliferation in human ischemic stroke.

Angiopoietin-1 is associated with cerebral vasospasm and delayed cerebral ischemia in subarachnoid hemorrhage

Background

Angiopoietin-1 (Ang-1) and -2 (Ang-2) are keyplayers in the regulation of endothelial homeostasis and vascular proliferation. Angiopoietins may play an important role in the pathophysiology of cerebral vasospasm (CVS). Ang-1 and Ang-2 have not been investigated in this regard so far.

Methods

20 patients with subarachnoid hemorrhage (SAH) and 20 healthy controls (HC) were included in this prospective study. Blood samples were collected from days 1 to 7 and every other day thereafter. Ang-1 and Ang-2 were measured in serum samples using commercially available enzyme-linked immunosorbent assay. Transcranial Doppler sonography was performed to monitor the occurrence of cerebral vasospasm.

Results

SAH patients showed a significant drop of Ang-1 levels on day 2 and 3 post SAH compared to baseline and HC. Patients, who developed Doppler sonographic CVS, showed significantly lower levels of Ang-1 with a sustained decrease in contrast to patients without Doppler sonographic CVS, whose Ang-1 levels recovered in the later course of the disease. In patients developing cerebral ischemia attributable to vasospasm significantly lower Ang-1 levels have already been observed on the day of admission. Differences of Ang-2 between SAH patients and HC or patients with and without Doppler sonographic CVS were not statistically significant.

Conclusions

Ang-1, but not Ang-2, is significantly altered in patients suffering from SAH and especially in those experiencing CVS and cerebral ischemia. The loss of vascular integrity, regulated by Ang-1, might be in part responsible for the development of cerebral vasospasm and subsequent cerebral ischemia.

Cd34+ progenitor cells likely are involved in the good functional recovery after intracerebral hemorrhage in humans

Bone marrow-derived stem/progenitor cells (CD34(+) progenitor cells) were demonstrated to play an important role in the regeneration of damaged brain tissue. Our aim was to study the influence of CD34(+) progenitor cells in the outcome of intracerebral hemorrhage (ICH). Thirty-two patients with primary ICH (64.0% male, mean age 67.1 ± 10.8 years) were prospectively included in the study within 12 hr of symptom onset. The main outcome variable was good functional outcome at 3 months (modified Rankin scale ≤ 2). Circulating CD34(+) progenitor cell levels were measured by flow cytometry at admission and at 7 ± 1 days, and serum levels of growth factors (determined by ELISA) were measured at admission and at 24 and 72 hr. Circulating levels of CD34(+) progenitor cells at day 7 were independently associated with good functional outcome at 3 months (OR 1.17, CI95% 1.06-1.39, P = 0.012). On the other hand, CD34(+) progenitor cells at day 7 were negatively correlated with residual cavity volume at 3 months (r = -0.607, P = 0.001). Serum levels of vascular endothelial growth factor (r = 0.386), angiopoietin 1 (r = 0.518), brain-derived neurotrophic factor (r = 0.484), and stromal cell-derived factor-1α (r = 0.837) but not granulocyte-colony stimulating factor (r = -0.038) at 72 hr showed a strong correlation with CD34(+) progenitor cell levels at day 7. These findings suggest that CD34(+) progenitor cells may participate in the functional recovery of ICH patients.

Stress and traumatic brain injury: a behavioral, proteomics, and histological study

Psychological stress and traumatic brain injury (TBI) can both result in lasting neurobehavioral abnormalities. Post-traumatic stress disorder and blast induced TBI (bTBI) have become the most significant health issues in current military conflicts. Importantly, military bTBI virtually never occurs without stress. In this experiment, we assessed anxiety and spatial memory of rats at different time points after repeated exposure to stress alone or in combination with a single mild blast. At 2 months after injury or sham we analyzed the serum, prefrontal cortex (PFC), and hippocampus (HC) of all animals by proteomics and immunohistochemistry. Stressed sham animals showed an early increase in anxiety but no memory impairment at any measured time point. They had elevated levels of serum corticosterone (CORT) and hippocampal IL-6 but no other cellular or protein changes. Stressed injured animals had increased anxiety that returned to normal at 2 months and significant spatial memory impairment that lasted up to 2 months. They had elevated serum levels of CORT, CK-BB, NF-H, NSE, GFAP, and VEGF. Moreover, all of the measured protein markers were elevated in the HC and the PFC; rats had an increased number of TUNEL-positive cells in the HC and elevated GFAP and Iba1 immunoreactivity in the HC and the PFC. Our findings suggest that exposure to repeated stress alone causes a transient increase in anxiety and no significant memory impairment or cellular and molecular changes. In contrast, repeated stress and blast results in lasting behavioral, molecular, and cellular abnormalities characterized by memory impairment, neuronal and glial cell loss, inflammation, and gliosis. These findings may have implications in the development of diagnostic and therapeutic measures for conditions caused by stress or a combination of stress and bTBI.

A large screening of angiogenesis biomarkers and their association with neurological outcome after ischemic stroke

BACKGROUND

The induction of angiogenesis after stroke may enhance neurorestorative processes. Our aim was to examine the endogenous angiogenesis balance and their association with long-term clinical outcome in ischemic stroke patients.

METHODS

A total of 109 stroke subjects were included in the study. Firstly, plasma samples were obtained from control subjects (n = 26) and tPA-treated stroke patients (n = 29) at baseline (within 3h of symptoms onset), 1, 2, 12, 24h after tPA treatment, at discharge and 3 months after the ischemic event. Angiogenic promoters (PDGF-AA, PDGF-BB, HGF, FGF, KGF, HB-EGF, TPO, VEGF, VEGFR-1, VEGFR-2 and SDF-1α) and inhibitors (endostatin, angiostatin, thrombospondin-1 and thrombospondin-2) were analyzed by Searchlight(®) technology or ELISA. Additionally, baseline and 24h endostatin plasma level was determined in a new set of stroke patients (n = 80). Clinical parameters (NIHSS, mRS, mortality and hemorrhagic transformation events) were assessed to evaluate outcome.

RESULTS

Baseline PDGF-BB, endostatin and thrombospondin-2 levels were higher in stroke patients than in controls (p < 0.05). A pro-angiogenic balance was associated with lower NIHSS scores and less intracranial hemorrhagic complications. Interestingly, a high baseline endostatin level was associated to long-term functional dependency (mRS > 2; p = 0.004). Finally, a baseline endostatin cut-off point of 184 ng/mL was an independent predictor of functional dependency at three months in the multiple logistic regression with an odds ratio of 8.9 (95% CI: 2.7-28.8; p = 0.0002).

CONCLUSIONS

Our results indicate that an early pro-angiogenic balance is associated with mild short-term neurological deficit, while an acute anti-angiogenesis status determined by high endostatin plasma level predicts a worse long-term functional outcome.

Exploring neuroprotective drug therapies for intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a devastating neurological disorder with high mortality and poor prognosis, for which virtually no effective drug therapies are available at present. Experimental animal models, based on intrastriatal injection of collagenase or autologous blood, have enabled great advances in elucidation of cellular/molecular events contributing to brain pathogenesis associated with ICH. Many lines of evidence indicate that blood constituents, including hemoglobin-derived products as well as proteases such as thrombin, play important roles in the pathogenic events. Inflammatory reactions involving neutrophils, activated microglia, and production of proinflammatory cytokines also constitute a critical aspect of pathology leading to neurodegeneration and tissue damage. Efforts are continuing to find drugs that potentially alleviate pathological and neurological outcomes of ICH. Various drugs that possess antioxidative, anti-inflammatory or neurotrophic/neuroprotective properties have been demonstrated to produce therapeutic effects on ICH animal models. Drugs already in clinical use such as minocycline, statins, and several nuclear receptor ligands are among the list of effective drugs, but whether they also show therapeutic efficacy in human ICH patients remains unproven. Here, current knowledge of ICH pathogenesis and problems arising with respect to exploration of new drug candidates are discussed.

A functional variant in the 3'-UTR of angiopoietin-1 might reduce stroke risk by interfering with the binding efficiency of microRNA 211

Angiopoietin-1 is a vascular strengthening factor during vascular development and a protective factor for pathological vascular inflammation and leakage. Brain vascular leaking and inflammation are two important pathological processes of stroke; therefore, we hypothesized that variants of the microRNA-binding site in angiopoietin-1 would affect its expression and confer a risk of stroke. To test our hypothesis, a predicted microRNA-binding site was found in the 3'-UTR of angiopoietin-1 using bioinformatics; variant rs2507800 was identified to be located in the miR-211-binding site of angiopoietin-1. Secondly, the effects of the identified variant on angiopoietin-1 translation were assessed using a luciferase reporter assay and ELISA. We found that the A allele of rs2507800 suppressed angiopoietin-1 translation by facilitating miR-211 binding, but not the T allele. Subjects carrying the TT genotype had higher plasma angiopoietin-1 levels than those with the A allele. Finally, the association of the variant with stroke was tested in 438 stroke patients and 890 controls, and replicated in an independent population of 1791 stroke patients and 1843 controls. The TT genotype resulted in a significant reduction in overall stroke risk {OR, 0.51 [95% confidence interval (CI), 0.36-0.74], P = 0.0003}, ischemic stroke [OR, 0.56 (95% CI, 0.36-0.85), P = 0.007] and hemorrhagic stroke [OR, 0.46 (95% CI, 0.26-0.80), P = 0.007]. These results were confirmed in an independent study. Our results provide evidence that the TT genotype (rs2507800) in the 3'-UTR of angiopoietin-1 might reduce the risk of stroke by interfering with miR-211 binding.