Fas System Activation in Perihematomal Areas After Spontaneous Intracerebral Hemorrhage

Multiplexing Biosensor for the Detection of Extracellular Vesicles as Biomarkers of Tissue Damage and Recovery after Ischemic Stroke

The inflammatory, reparative and regenerative mechanisms activated in ischemic stroke patients immediately after the event cooperate in the response to injury, in the restoration of functions and in brain remodeling even weeks after the event and can be sustained by the rehabilitation treatment. Nonetheless, patients' response to treatments is difficult to predict because of the lack of specific measurable markers of recovery, which could be complementary to clinical scales in the evaluation of patients. Considering that Extracellular Vesicles (EVs) are carriers of multiple molecules involved in the response to stroke injury, in the present study, we have identified a panel of EV-associated molecules that (i) confirm the crucial involvement of EVs in the processes that follow ischemic stroke, (ii) could possibly profile ischemic stroke patients at the beginning of the rehabilitation program, (iii) could be used in predicting patients' response to treatment. By means of a multiplexing Surface Plasmon Resonance imaging biosensor, subacute ischemic stroke patients were proven to have increased expression of vascular endothelial growth factor receptor 2 (VEGFR2) and translocator protein (TSPO) on the surface of small EVs in blood. Besides, microglia EVs and endothelial EVs were shown to be significantly involved in the intercellular communications that occur more than 10 days after ischemic stroke, thus being potential tools for the profiling of patients in the subacute phase after ischemic stroke and in the prediction of their recovery.

Elevated soluble fas blood concentrations in patients dying from spontaneous intracerebral hemorrhage

BACKGROUND

Several studies of spontaneous intracerebral hemorrhage (SICH) patients have shown apoptotic changes in brain samples after hematoma evacuation. However, there have been no data on the association between blood concentrations of soluble fas (sFas) (the main surface death receptor of the extrinsic apoptosis pathway) and the prognosis of spontaneous intracranial hypotension (SIH) patients.

AIM

To determine whether there is an association between blood sFas concentrations and SICH patient mortality.

METHODS

We included patients with severe and supratentorial SIH. Severe was defined as having Glasgow Coma Scale < 9. We determined serum sFas concentrations at the time of severe SICH diagnosis.

RESULTS

We found that non-surviving patients (n = 36) compared to surviving patients (n = 39) had higher ICH score (P = 0.001), higher midline shift (P = 0.004), higher serum sFas concentrations (P < 0.001), and lower rate of early hematoma evacuation (P = 0.04). Multiple logistic regression analysis showed an association between serum sFas concentrations and 30-d mortality (odds ratio = 1.070; 95% confidence interval = 1.014-1.129; P = 0.01) controlling for ICH score, midline shift, and early hematoma evacuation.

CONCLUSION

The association of blood sFas concentrations and SICH patient mortality is a novel finding in our study.

The Role of Caspase Family in Acute Brain Injury: The Potential Therapeutic Targets in the Future

The caspase family is commonly involved in the pathophysiology of acute brain injury (ABI) through complex apoptotic, pyroptotic, and inflammatory pathways. Current translational strategies for caspase modulation in ABI primarily focus on caspase inhibitors. Because there are no caspase-inhibiting drugs approved for clinical use on the market, the development of caspase inhibitors remains an attractive challenge for researchers and clinicians. Therefore, we conducted the present review with the aim of providing a comprehensive introduction of caspases in ABI. In this review, we summarized the available evidence and potential mechanisms regarding the biological function of caspases. We also reviewed the therapeutic effects of caspase inhibitors on ABI and its subsequent complications. However, various important issues remain unclear, prompting further verification of the efficacy and safety regarding clinical application of caspase inhibitors. We believe that our work will be helpful to further understand the critical role of the caspase family and will provide novel therapeutic potential for ABI treatment.

Mortality prediction of patients with spontaneous intracerebral hemorrhage by serum soluble Fas ligand concentrations

BACKGROUND

A study of patients with spontaneous intracerebral hemorrhage (SIH) found a higher content of Fas ligand in the perihematomic brain area compared to healthy brain areas. The objective of this study was to analyze whether blood soluble Fas ligand (sFasL) concentrations could be used to estimate the prognosis of SIH patients.

METHODS

Observational and prospective study performed in five Spanish Intensive Care Units. Patients with severe supratentorial SIH, defined as Glasgow Coma Scale (GCS) <9, were included. Serum sFasL levels were determined at the time of diagnosis of severe SIH. Mortality at 30 days was the end-point study.

RESULTS

Surviving SIH patients (n = 41) compared to nonsurvivors (n = 38) showed lower serum sFasL levels (p < 0.001). The area under curve of mortality prediction for serum sFasL levels was 0.79 (95% CI = 0.70-0.89; p < 0.001). Multiple logistic regression analysis found an association of serum sFasL concentrations with 30-day mortality (ORo = 1,034; 95% CI = 1,010-1,058; p = 0,006) after controlling for midline shift, early hematoma evacuation, and intracerebral hemorrhage score.

CONCLUSIONS

The capability of serum sFasL to predict SIH patient mortality is the main novel finding of our study.

ABBREVIATIONS

APACHE II: Acute Physiology and Chronic Health Evaluation; aPTT: activated partial thromboplastin time; FIO₂: fraction of inspired oxygen; GCS: Glasgow Coma Scale; ICU: Intensive Care Unit; INR: international normalized ratio; PaO₂: pressure of arterial oxygen.

Incremental Accuracy of Blood Biomarkers for Predicting Clinical Outcomes After Intracerebral Hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) is associated with high mortality, morbidity, and recurrence. Studies have reported the accuracy of several blood biomarkers in predicting clinical outcomes; however, their independent contribution in prediction remains to be established.

AIM

To investigate the incremental accuracy in predicting clinical outcomes in patients with ICH in a north Indian population using blood-based biomarkers.

METHODS

In this study, a total of 250 ICH cases were recruited within 72 hours of onset. Baseline clinical and CT scan measurement were recorded. Homocysteine (HCY), C-reactive protein (CRP), matrix metalloproteinase-9 (MMP9), E-selectin (SELE), and P-selectin (SELP) levels were measured through ELISA. Telephonic follow-up was done by using mRS scale at three months.

RESULTS

The mean age of cohort was 54.9 (SD±12.8) years with 64.8% patients being male. A total of 109 (43.6%) deaths were observed over three months follow-up. Area under the receiver operating characteristics curve-(AUROC) for 90-day mortality were 0.55 (HCY), 0.62 (CRP), 0.57 (MMP9), 0.60 (SELE) and 0.53 (SELP) and for poor outcome at 90-day (mRS: 3-6) were 0.60 (HCY), 0.62 (CRP), 0.54 (MMP9), 0.67 (SELE) and 0.54 (SELP). In multivariable model including age, ICH volume, IVH and GCS at admission, serum SELE (p=0.004) significant for poor outcome with improved AUROC (0.86) and HCY (p=0.04), CRP (p=0.003) & MMP9 (p=0.02) for mortality with least Akaike's Information Criterion-(AIC) (1060.5).

CONCLUSIONS

Our findings suggest that the serum SELE is a significant predictor of poor outcome and HCY, CRP & MMP9 for Mortality in patients with ICH in the north Indian population.

Galectin-9 Promotes Neuronal Restoration via Binding TLR-4 in a Rat Intracerebral Hemorrhage Model

Intracerebral hemorrhage (ICH) is a devastating disease with high rates of mortality and morbidity. Galactose lectin-9 (Gal-9) belongs to the family of β-galactoside-binding lectins, which has been shown to play a vital role in immune tolerance and inflammation. However, the function of Gal-9 in ICH has not been fully studied in details. Several experiments were carried out to explore the role of Gal-9 in the late period of ICH. Primarily, ICH models were established in male adult Sprague Dawley (SD) rats. Next, the relative protein levels of Gal-9 at different time points after ICH were examined and the result showed that the level of Gal-9 increased and peaked at the 7th day after ICH. Then we found that when the content of Gal-9 increased, both the number of M2-type microglia and the corresponding anti-inflammatory factors also increased. Through co-immunoprecipitation (CO-IP) analysis, it was found that Gal-9 combines with Toll-like receptor-4 (TLR-4) during the period of the recovery after ICH. TUNEL staining and Fluoro-Jade B staining (FJB) proved that the amount of cell death decreased with the increase of Gal-9 content. Additionally, several behavioral experiments also demonstrated that when the level of Gal-9 increased, the motor, sensory, learning, and memory abilities of the rats recovered better compared to the ICH group. In short, this study illustrated that Gal-9 takes a crucial role after ICH. Enhancing Gal-9 could alleviate brain injury and promote the recovery of ICH-induced injury, so that Gal-9 may exploit a new pathway for clinical treatment of ICH.

Activated WNK3 induced by intracerebral hemorrhage deteriorates brain injury maybe via WNK3/SPAK/NKCC1 pathway

BACKGROUND

Intracerebral hemorrhage (ICH) is the common brain diseases in middle-aged and elderly people, with high disability and/or mortality rate, and is a serious public health concern. Both WNK3 kinase and the WNK3/SPAK/NKCC1 signaling pathway play an integral role in maintaining normal cell homeostasis. However, their role and underlying mechanisms in ICH-induced secondary brain injury (SBI) have yet to be elucidated.

METHODS

We established an ICH model using male Sprague-Dawley (SD) rats by injecting autologous arterial blood into the unilateral basal ganglia. To establish ICH model in vitro, oxyhemoglobin (OxyHb; 20 μM) and neurons were cultured for 6 h at 37 °C, 5% CO₂ atmosphere. To investigate the role of WNK3 and the WNK3/SPAK/NKCC1 signaling pathway in SBI, after genetic interventions, rotation and water maze test, brain edema and neuroinflammation were detected, and terminal-deoxynucleoitidyl transferase mediated dUTP nick end labeling (TUNEL), Fluoro-Jade C (FJC), and Nissl staining were performed.

RESULTS

Our data showed that WNK3 expression in brain tissue were upregulated after ICH induction. In addition, silencing of WNK3 reduced neuronal apoptosis, and inflammatory responses in rats that underwent ICH. Inhibition of WNK3 expression reduced the damaged blood-brain barrier (BBB), alleviated the impaired degree of cerebral edema, and improved disruptive neurobehavioral cognition caused by ICH. Moreover, overexpression of WNK3 had the opposite effects. Finally, WNK3/SPAK/NKCC1 signaling pathway may be involved in the above-mentioned processes.

CONCLUSIONS

In conclusion, our findings showed that WNK3 and WNK3/SPAK/NKCC1 signaling pathway play a vital biological function in ICH-induced SBI. Depletion of WNK3 attenuated brain injury after ICH both in vivo and in vitro. Thus, WNK3 and WNK3/SPAK/NKCC1 signaling pathway are potential targets for treating SBI after ICH.

Exploration of MST1-Mediated Secondary Brain Injury Induced by Intracerebral Hemorrhage in Rats via Hippo Signaling Pathway

Intracerebral hemorrhage (ICH) is a serious public health problem which causes high rates of disability and mortality in adults. Cell apoptosis is a sign of secondary brain injury (SBI) following ICH. Mammalian sterile 20-like kinase-1 (MST1), an apoptosis-promoting kinase, is a part of the Hippo signaling pathway and involved in cell death, oxidative stress, and inflammation. However, the role and underlying mechanism of MST1 in SBI induced by ICH have not yet been fully explained. The main purpose of present research was to explore the role of MST1 and its potential mechanism in SBI after ICH. An ICH model was established by injecting autologous blood into the right basal ganglia in male SD rats. We found that MST1 phosphorylation was significantly increased in brain tissues of rats after ICH. Additionally, inhibition of MST1 phosphorylation by a chemical inhibitor (Xmu-mp-1) and genetic knockdown could effectively reduce the activation of P-LATS1 and P-YAP which are downstream proteins of MST1 and decrease neuronal cell death and inflammation reaction in ICH rats. Furthermore, the decreased of MST1 phosphorylation reduced brain edema, blood-brain barrier (BBB) damage, and neurobehavioral impairment during ICH. Over-expression of MST1 resulted in opposite effects. Finally, deletion of MST1 significantly reduced neuronal apoptosis in vitro. In summary, our study revealed that MST1 played an important role in the SBI following ICH, and inhibition of MST1 could alleviate ICH-induced SBI. Therefore, MST1 may be considered as a potential therapeutic target for SBI following ICH.

Role for RIP1 in mediating necroptosis in experimental intracerebral hemorrhage model both in vivo and in vitro

Cell death is a hallmark of second brain injury after intracerebral hemorrhage (ICH); however, the mechanism still has not been fully illustrated. In this study, we explored whether necroptosis, a type of regulated necrosis, has an essential role in brain injury after ICH. We found that inhibiting receptor-interacting protein 1 (RIP1) – a core element of the necroptotic pathway – by a specific chemical inhibitor or genetic knockdown attenuated brain injury in a rat model of ICH. Furthermore, necroptosis of cultured neurons could be induced by conditioned medium from microglia stimulated with oxygen hemoglobin, and this effect could be inhibited by TNF-α inhibitor, indicating that TNF-α secreted from activated microglia is an important factor in inducing necroptosis of neurons. Undoubtedly, overexpression of RIP1 increased conditioned medium-induced necroptosis in vitro, but this effect was partially diminished in mutation of serine kinase phosphorylation site of RIP1, showing that phosphorylation of RIP1 is the essential molecular mechanism of necroptosis, which was activated in the in vitro model of ICH. Collectively, our investigation identified that necroptosis is an important mechanism of cell death in brain injury after ICH, and inhibition of necroptosis may be a potential therapeutic intervention of ICH.

Stroke increases the risk of hip fracture: a systematic review and meta-analysis

Many studies have investigated the association between stroke and hip fracture risk, but the precise association was still unclear due to insufficient statistical power in single studies with relatively small sample size. Thus, we firstly conducted a meta-analysis of all published studies to precisely estimate the relationship of stroke with hip fracture risk. The strength for this relationship was weighed by pooled relative risks (RRs) with 95 % confidence intervals (95 % CIs) after adjustment for confounding variables. Stratified analyses by study design and ethnicity and sensitivity analysis were also performed. Two investigators independently performed a comprehensive literature search in databases of PubMed, Embase, and Wanfang for eligible articles. A Bayesian meta-analysis was also performed to get a more precise assessment of the relationship. Eleven relevant studies from 10 publications were finally included into our meta-analysis according to the inclusion criteria. Overall, stroke significantly and independently increased the risk of hip fracture (RR = 2.06, 95 % CI 1.68-2.52, P < 0.001). Bayesian meta-analysis showed that stroke was also associated with an over two-fold increased risk of hip fracture (RR = 2.11, 95 % CI 1.62-2.75). In stratified analysis, stroke could increase the risk of hip fracture in Caucasians (RR = 2.36, 95 % CI 1.83-3.05, P < 0.001). These data support the notion that stroke is an independent risk factor for hip fracture, and patients with stroke have a two-fold increased risk of hip fracture than those without stroke.

Stages of the Inflammatory Response in Pathology and Tissue Repair after Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a major health concern, with high rates of mortality and morbidity and no highly effective clinical interventions. Basic research in animal models of ICH has provided insight into its complex pathology, in particular revealing the role of inflammation in driving neuronal death and neurologic deficits after hemorrhage. The response to ICH occurs in four distinct phases: (1) initial tissue damage and local activation of inflammatory factors, (2) inflammation-driven breakdown of the blood-brain barrier, (3) recruitment of circulating inflammatory cells and subsequent secondary immunopathology, and (4) engagement of tissue repair responses that promote tissue repair and restoration of neurologic function. The development of CNS inflammation occurs over many days after initial hemorrhage and thus may represent an ideal target for treatment of the disease, but further research is required to identify the mechanisms that promote engagement of inflammatory versus anti-inflammatory pathways. In this review, the authors examine how experimental models of ICH have uncovered critical mediators of pathology in each of the four stages of the inflammatory response, and focus on the role of the immune system in these processes.

Functional outcome after intracerebral haemorrhage – a review of the potential role of antiapoptotic agents

Intracerebral haemorrhage (ICH) is the second most common form of stroke and is associated with greater mortality and morbidity compared with ischaemic stroke. The current ICH management strategies, which mainly target primary injury mechanisms, have not been shown to improve patient’s functional outcome. Consequently, multimodality treatment approaches that will focus on both primary and secondary pathophysiology have been suggested. During the last decade, a proliferation of experimental studies has demonstrated the role of apoptosis in secondary neuronal loss at the periphery of the clot after ICH. Subsequently, the value of certain antiapoptotic agents in reducing neuronal death and improving functional outcome following ICH was evaluated in animal models. Preliminary evidence from those studies strongly supports the potential role of antiapoptotic agents in reducing neuronal death and improving functional outcome after intracerebral haemorrhage. Expectedly, the ongoing and subsequent clinical trials will substantiate these findings and provide clear information on the most potent and safe antiapoptotic agents, their appropriate dosage, and temporal window of action, thereby making them suitable for the multimodality treatment approach.

Predictive value of serum caspase-cleaved cytokeratin-18 concentrations after acute intracerebral hemorrhage

BACKGROUND

Caspase-cleaved Cytokeratin-18 (CCCK-18) is released during apoptosis. Serum CCCK-18 concentrations are associated with prognosis of some critical illness. We investigated the potential relationships between serum CCCK-18 concentrations and disease severity and long-term clinical outcomes after intracerebral hemorrhage.

METHODS

Serum CCCK-18 concentrations were determined in a total of 102 patients and 102 controls. Multivariate models were used to predict high concentration of CCCK-18 and 6-month clinical outcomes. The predictive values were evaluated based on areas under receiver operating curve.

RESULTS

Compared with controls, serum CCCK-18 concentrations were increased in patients (245.8±108.3U/l vs. 23.6±18.1U/l, P<0.001). National Institute of Health Stroke Scale scores [odds ratio (OR), 1.164; 95% confidence interval (CI), 1.027-1.320; P=0.003] and hematoma volumes (OR, 1.079; 95% CI, 1.018-1.205; P=0.008) were independent predictors of high concentration of CCCK-18. CCCK-18 was identified as an independent predictor of 6-month mortality (OR, 1.019; 95% CI, 1.010-1.038; P=0.013) and 6-month unfavorable outcome (OR, 1.017; 95% CI, 1.008-1.029; P=0.032) and possessed high predictive values.

CONCLUSION

Increased serum CCCK-18 concentrations are associated with disease severity and clinical outcomes, suggesting that CCCK represent a novel prognostic predictive biomarker after intracerebral hemorrhage.

Effects of local hypothermia on neuronal cell apoptosis after intracerebral hemorrhage in rats

OBJECTIVES

Intracerebral hemorrhage (ICH) is a devastating subtype of stroke that is characterized by significant morbidity and mortality. Thus far, there is no effective treatment option for spontaneous ICH. In this study, we aimed to investigate the effects of local hypothermia on brain injuries after ICH.

MEASUREMENTS

Bacterial collagenase was used to induce ICH stroke in male Wistar rats. We assessed the effects of normothermia and 4 hours of local hypothermia (~33.2°C) initiated 1 hour after collagenase infusion on the neurological outcomes and brain water content at 1 and 3 days after ICH. The pathological changes of neuronal ultrastructure were examined with transmission electron microscopy. Furthermore, the expression levels of apoptotic molecules and matrix metalloproteinases-9 (MMP-9) were determined using western blotting and immunohistochemical staining. Results :Local hypothermia tends to reduce neurological deficits compared with the normothermic group at day 3 after ICH. Transmission electron microscopy reveals that local hypothermia significantly improves the ultrastructural outcomes at 1 and 3 days after ICH. In addition, local hypothermia markedly reduces edema formation and the expression levels of MMP-9 and apoptotic signal.

CONCLUSION

These data suggest that local hypothermia induces a reduction in the brain edema and partly reduces neurological deficits along with marked inhibitory effects on MMP-9 and cell apoptosis after ICH.

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).

Association between plasma levels of hyaluronic acid and functional outcome in acute stroke patients

Background

Activation of hyaluronic acid (HA) and associated enzyme synthesis has been demonstrated in experimental stroke animal models. Our study aimed to investigate the plasma levels of HA in acute stroke patients and the associations between HA levels and functional outcome.

Methods

This was a multicenter case–control study. Acute stroke patients and age- and sex-matched non-stroke controls were recruited. Plasma levels of HA in acute stroke patients were determined at <48 hours and at 48 to 72 hours after stroke onset by standard ELISA. Favorable functional outcome was defined as modified Rankin scale ≤2 at 3 months after stroke.

Results

The study included 206 acute stroke patients, including 43 who had intracerebral hemorrhage and 163 who had ischemic stroke, and 159 controls. The plasma levels of HA in the acute stroke patients were significantly higher than those in the controls (219.7 ± 203.4 ng/ml for <48 hours and 343.1 ± 710.3 ng/ml for 48 to 72 hours versus 170.4 ± 127.9 ng/ml in the controls; both P < 0.05). For intracerebral hemorrhage patients, HA ≤500 ng/ml (<48 hours) was an independent favorable outcome predictor (P = 0.016). For ischemic stroke patients, an inverted U-shaped association between plasma HA (48 to 72 hours) and outcome was noted, indicating that ischemic stroke patients with too high or too low plasma HA levels tended to have an unfavorable outcome.

Conclusion

HA plasma level was elevated in patients with acute stroke, and can predict 3-month functional outcome, particularly for patients with intracerebral hemorrhage.

Necrostatin-1 reduces neurovascular injury after intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is the most common form of hemorrhagic stroke, accounting for 15% of all strokes. ICH has the highest acute mortality and the worst long-term prognosis of all stroke subtypes. Unfortunately, the dearth of clinically effective treatment options makes ICH the least treatable form of stroke, emphasizing the need for novel therapeutic targets. Recent work by our laboratory identified a novel role for the necroptosis inhibitor, necrostatin-1, in limiting neurovascular injury in tissue culture models of hemorrhagic injury. In the present study, we tested the hypothesis that necrostatin-1 reduces neurovascular injury after collagenase-induced ICH in mice. Necrostatin-1 significantly reduced hematoma volume by 54% at 72 h after-ICH, as compared to either sham-injured mice or mice administered an inactive, structural analogue of necrostatin-1. Necrostatin-1 also limited cell death by 48%, reduced blood-brain barrier opening by 51%, attenuated edema development to sham levels, and improved neurobehavioral outcomes after ICH. These data suggest a potential clinical utility for necrostatin-1 and/or novel necroptosis inhibitors as an adjunct therapy to reduce neurological injury and improve patient outcomes after ICH.

Inflammation in intracerebral hemorrhage: from mechanisms to clinical translation

Intracerebral hemorrhage (ICH) accounts for 10-15% of all strokes and is associated with high mortality and morbidity. Currently, no effective medical treatment is available to improve functional outcomes in patients with ICH. Potential therapies targeting secondary brain injury are arousing a great deal of interest in translational studies. Increasing evidence has shown that inflammation is the key contributor of ICH-induced secondary brain injury. Inflammation progresses in response to various stimuli produced after ICH. Hematoma components initiate inflammatory signaling via activation of microglia, subsequently releasing proinflammatory cytokines and chemokines to attract peripheral inflammatory infiltration. Hemoglobin (Hb), heme, and iron released after red blood cell lysis aggravate ICH-induced inflammatory injury. Danger associated molecular patterns such as high mobility group box 1 protein, released from damaged or dead cells, trigger inflammation in the late stage of ICH. Preclinical studies have identified inflammatory signaling pathways that are involved in microglial activation, leukocyte infiltration, toll-like receptor (TLR) activation, and danger associated molecular pattern regulation in ICH. Recent advances in understanding the pathogenesis of ICH-induced inflammatory injury have facilitated the identification of several novel therapeutic targets for the treatment of ICH. This review summarizes recent progress concerning the mechanisms underlying ICH-induced inflammation. We focus on the inflammatory signaling pathways involved in microglial activation and TLR signaling, and explore potential therapeutic interventions by targeting the removal of hematoma components and inhibition of TLR signaling.

Homocysteine and C-reactive protein associated with progression and prognosis of intracranial branch atheromatous disease

BACKGROUND AND OBJECTIVES

C-reactive protein (CRP) is a biomarker of inflammation and a sensitive predictor of stroke, and high homocysteine (Hcy) is also associated with stroke. However, the roles of CRP and Hcy in the pathogenesis, progression and prognosis of branch atheromatous disease (BAD) and lipohyalinotic degeneration (LD) are largely unknown. We sought to determine the relation between them in Chinese patients.

METHODS

According to the lesion presences shown by diffusion-weighted imaging (DWI), we retrospectively recruited a cohort of 308 patients with a diagnosis of BAD and LD from a total of 1458 consecutive patients with acute ischemic stroke. Progression was defined as worsening by > or  = 1-point in the NIHSS for motor function within the first 5 days. Good outcome was deemed as Modified Rankin Scale (mRS) ≤ 2 and poor outcome was mRS > 2 recorded at one month after onset.

RESULTS

This study comprised a total of 179 patients with BAD and 129 patients with LD. Subjects in patients with LD significantly had an elevated Hcy (p = 0.030), a lower NIHSS score on admission (p<0.001) and mRS score at one month after ictus (p<0.001) than those in patients with BAD. Elevated Hcy (P = 0.004) and increased CRP (P = 0.025) were associated with progression in patients with BAD, and CRP (p = 0.006) and diabetes mellitus (p = 0.011) were found to be associated with poor outcome in patients with BAD. However, no association was observed in patients with LD on progression and prognosis. After multivariate logistic regression analysis, elevated Hcy (p = 0.002) remained the only independent predictor for the progression, and increased CRP (p = 0.027) and smoking (p = 0.012) became the independent predictors for the poor outcome in patients with BAD.

CONCLUSIONS

In patients with BAD, elevated Hcy and increased CRP may independently predict progression and prognosis, respectively.

The protective role of oxymatrine on neuronal cell apoptosis in the hemorrhagic rat brain

ETHNOPHARMACOLOGICAL RELEVANCE

Oxymatrine is extracted from the traditional Chinese herb Sophora flavescens Ait, possesses anti-inflammatory, anti-oxidative and anti-apoptotic properties, and has been used for the treatment of chronic viral hepatitis and many other diseases.

AIMS OF THE STUDY

This study aimed to investigate the effects of oxymatrine on inflammatory response mediated by Toll-like receptor4 (TLR4) and nuclear factor kappa-B (NF-κB), oxidative injury induced by 12/15 lipoxygenase (12/15-LOX), phosphorylated p38 mitogen activated protein kinase (phosphor-p38 MAPK) and cytosolic phospholipase A2 (cPLA2), and neuronal cell apoptosis in rat brain with intracerebral hemorrhage (ICH).

MATERIALS AND METHODS

Wistar rats were treated intraperitoneally with 60 or 120mg/kg of oxymatrine daily for 5 days following ICH. The rats were sacrificed at hour 2, 6, 12, 24, 48, 72, and 120 after ICH. The gene expressions of TLR-4 and NF-κB, the levels of TNF-alpha, interleukin-1beta, interleukin-6, 12/15-LOX, phospho-p38 MAPK and cPLA2, and the number of apoptotic neuronal cells in rat brain were determined.

RESULTS

Oxymatrine at 120mg/kg significantly suppressed gene expressions of TLR-4 and NF-κB, decreased levels of TNF-alpha, interleukin-1beta and interleukin-6, inhibited synthesis of 12/15-LOX, phospho-p38 MAPK and cPLA2 protein, and mitigated apoptotic neuronal changes following ICH in rat.

CONCLUSION

Oxymatrine at 120mg/kg following ICH inhibits inflammatory responses, oxidative injury, and neuronal cell apoptosis in rats.

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.

Intracerebral haemorrhage: mechanisms of injury and therapeutic targets

Intracerebral haemorrhage accounts for about 10-15% of all strokes and is associated with high mortality and morbidity. No successful phase 3 clinical trials for this disorder have been completed. In the past 6 years, the number of preclinical and clinical studies focused on intracerebral haemorrhage has risen. Important advances have been made in animal models of this disorder and in our understanding of mechanisms underlying brain injury after haemorrhage. Several therapeutic targets have subsequently been identified that are now being pursued in clinical trials. Many clinical trials have been based on limited preclinical data, and guidelines to justify taking preclinical results to the clinic are needed.

VAP-1/SSAO plasma activity and brain expression in human hemorrhagic stroke

BACKGROUND

Vascular adhesion protein-1 (VAP-1) is a cell surface and circulating enzyme that belongs to the semicarbazide-sensitive amine oxidase (SSAO) family, which oxidatively deaminates primary amines and is implicated in leukocyte extravasation. Our aim was to investigate the alteration of soluble VAP-1/SSAO activity in plasma samples after acute intracerebral hemorrhage (ICH) and its presence in human ICH brain tissue.

METHODS

VAP-1/SSAO activity was determined in plasma of 66 ICH patients and 58 healthy controls. In addition, we assessed the expression of VAP-1/SSAO in postmortem brain tissue from hemorrhagic stroke patients by Western blot and immunohistochemistry.

RESULTS

We observed significantly higher levels of plasma VAP-1/SSAO activity in patients with ICH compared to matched elderly controls (p = 0.001). Plasma VAP-1/SSAO activity <2.7 pmol/min·mg and baseline ICH volume <17 ml were independent predictors of neurological improvement after 48 h (OR 6.8, 95% CI 1.14-41.67, p = 0.035, and OR 10.64, 95% CI 1.1-100, p = 0.041, respectively), after adjustment for baseline stroke severity. We also found that membrane-bound VAP-1/SSAO levels were lower in the perihematoma region than in the corresponding contralateral brain areas of patients deceased due to ICH (p = 0.024).

CONCLUSIONS

Our data demonstrate that plasma VAP-1/SSAO activity is increased in ICH and predicts neurological outcome, suggesting a possible contribution of the soluble protein in secondary brain damage. Furthermore, anti-VAP-1/SSAO strategies might be a promising approach to prevent neurological worsening following ICH.

Perihematomal pathological changes in neurons and astrocytes following acute cerebral hemorrhage

We aim to investigate the pathological temporospatial characteristics of brain cell injury in the perihematomal areas. Brain autopsy samples from 44 consecutive cases of intracerebral hemorrhage were processed and analyzed following immunohistochemical staining for neurofilament (NF) and glial fibrillary acidic protein (GFAP). NF and GFAP positive cells were scored and graded according to the distance from the hematoma and the time from the onset of hematoma formation. The tissues from the same region on the contralateral side of the brain were used as controls. Neurons in the perihematomal areas exhibited pyknosis or swollen necrosis, while astrocytes were swollen. Morphological abnormalities pertaining to NF appearance were attenuated with increasing distance from the hematoma wall, but were exacerbated with prolonged bleeding time. The level of NF staining abnormality was positively correlated with time from the onset of hematoma within 7 days of intracerebral hemorrhage. In contrast, the intensity of GFAP staining was negatively correlated with time from the onset of hematoma formation. This immunoreactivity was significantly higher closer to hematoma. Taken together, these data indicate that pathological alterations in neurons and astrocytes in the perihematomal area change with time from the onset of hematoma formation.

Emerging topics and new perspectives on HLA-G

Following the Fifth International Conference on non-classical HLA-G antigens (HLA-G), held in Paris in July 2009, we selected some topics which focus on emerging aspects in the setting of HLA-G functions. In particular, HLA-G molecules could play a role in: (1) various inflammatory disorders, such as multiple sclerosis, intracerebral hemorrhage, gastrointestinal, skin and rheumatic diseases, and asthma, where they may act as immunoregulatory factors; (2) the mechanisms to escape immune surveillance utilized by several viruses, such as human cytomegalovirus, herpes simplex virus type 1, rabies virus, hepatitis C virus, influenza virus type A and human immunodeficiency virus 1 (HIV-1); and (3) cytokine/chemokine network and stem cell transplantation, since they seem to modulate cell migration by the downregulation of chemokine receptor expression and mesenchymal stem cell activity blocking of effector cell functions and the generation of regulatory T cells. However, the immunomodulatory circuits mediated by HLA-G proteins still remain to be clarified.

Qingkailing injection attenuates apoptosis and neurologic deficits in a rat model of intracerebral hemorrhage

AIM OF THE STUDY

Traditional Chinese herb Angong Niuhuang Pill (AGNHP) is a famous preparation for neurological diseases; Qingkailing injection (QKL), an extract of AGNHP has similar clinical applications. This investigation was designed to further elucidate the neuroprotective effect of QKL on intracerebral hemorrhage (ICH).

MATERIALS AND METHODS

ICH was produced in adult Sprague-Dawley rats by injection of collagenase IV. Three incremental doses of QKL injection including low-(0.5 ml/kg), moderate-(1 ml/kg) and high-dosage (2 ml/kg) were administered twice, 3 and 12h following ICH. TUNEL and caspase-3 activity were measured at 1d after ICH, and apomorphine-induced rotation was evaluated at 1d, 7d, 14 d and 28 d.

RESULTS

Administration of high-dose QKL inhibited TUNEL positive cells (p<0.05) and caspase-3 activity (p<0.05) at 1d following ICH, and reduced apomorphine-induced rotation at 1d (p<0.01), 7d, 14 d and 28 d (p<0.05), compared with the controls. However, QKL in a low or moderate dose had no such effect.

CONCLUSION

QKL reduced brain damage of intracerebral hemorrhage through inhibiting apoptosis, which suggested a potential intervention for ICH patients.

Molecular biomarkers in stroke diagnosis and prognosis

Serum biomarkers related to the cascade of inflammatory, hemostatic, glial and neuronal perturbations have been identifed to diagnose and characterize intracerebral hemorrhage and cerebral ischemia. Interpretation of most markers is confounded by their latent rise, blood-brain barrier effects, the heterogeneity of etiologies and the wide range of normal values, limiting their application for early diagnosis, lesion size estimation and long-term outcome prediction. Certain hemostatic and inflammatory constituents have been found to predict response to thrombolysis and worsening due to infarct progression and secondary hemorrhage, offering a potential role for improved treatment selection and individualization of therapy. Biomarkers will become increasingly relevant for developing targets for neuroprotective therapies, monitoring response to treatment and as surrogate end points for treatment trials.

Hemin-induced necroptosis involves glutathione depletion in mouse astrocytes

Intracerebral hemorrhage (ICH) is a devastating neurological injury associated with significant mortality. Astrocytic inflammation may contribute to the pathogenesis of ICH, although the underlying cellular mechanisms remain unclear. In this study, the hemoglobin oxidation by-product, hemin, concentration dependently induced necroptotic cell death in cortical astrocytes within 5 h of treatment. Hemin-induced cell death was preceded by increased inflammatory gene expression (COX-2, IL-1beta, TNF-alpha, iNOS). Inhibition of the NF-kappaB transcription factor reversed inflammatory gene expression and attenuated cell death after hemin treatment, suggesting a possible role for inflammatory mediators in astrocytic injury. Superoxide production paralleled the increase in iNOS expression, and inhibition of either iNOS (aminoguanidine or iminopiperdine) or superoxide (apocynin) significantly reduced cell death. Similarly, reduced formation of peroxynitrite, the damaging product of nitric oxide and superoxide, significantly reduced hemin injury. Hemin-induced peroxidative injury was associated with a rapid depletion of intracellular glutathione (GSH), culminating in lipid peroxidation and cell death, effects that were reduced by cotreatment with exogenous GSH, N-acetyl-L-cysteine, or the glutathione peroxidase mimetic ebselen. Together, these studies suggest a novel role for GSH depletion in necroptotic astrocyte injury after a hemorrhagic injury and indicate that therapeutic targeting of GSH may exert a beneficial effect after ICH.