Correlation of free radical level and apoptosis after intracerebral hemorrhage in rats

Magnesium sulfate in the management of acute ischemic stroke: A review of the literature and future directions

BACKGROUND

The management of acute ischemic stroke (AIS) was revolutionized within the last 15 years with the introduction of mechanical thrombectomy (MT) to standard of care. Despite the success of mechanical thrombectomy (MT) in achieving high recanalization rates for large vessel occlusion, functional independence post-treatment remains suboptimal. The current limitations of MT prompt evaluation of the role of adjunctive pharmacologic neuroprotective therapies to prevent excitotoxicity, cellular apoptosis, and inflammation that cause irreversible neuronal damage during AIS. Magnesium (MgSO4) provides an attractive neuroprotectant profile, having many different effects, and is inexpensive, readily available, and has a long-established safety and tolerability profile in the management of myocardial infarction and eclampsia.

OBSERVATIONS

This gap between technical success and patient outcomes is largely due to the inability to fully protect brain tissue from infarction during ischemia. MgSO4 has shown promise in preclinical studies for its neuroprotective properties, including blocking NMDA receptors, increasing cerebral blood flow, and stabilizing ion channels. However, clinical trials, such as FAST-MAG and IMAGES, failed to demonstrate significant benefits when MgSO4 was administered intravenously, due to delayed drug administration or delivery to target tissue. These trials highlighted the need for faster, more targeted drug delivery. Intra-arterial (IA) administration of MgSO4 via the catheter used in MT could address these limitations by delivering high doses directly to ischemic brain tissue, potentially enhancing neuroprotection while reducing systemic exposure. Preclinical studies and some clinical trials have demonstrated the safety and feasibility of IA, but not IA MgSO4. Further investigation is needed to assess its efficacy.

CONCLUSIONS

While past trials have not succeeded, IA administration of neuroprotective agents like MgSO4 may improve functional outcomes in stroke patients post-MT. Ongoing and future studies will determine if this approach can effectively complement reperfusion strategies, potentially ushering in a new era of stroke care.

Mechanism and treatment of intracerebral hemorrhage focus on mitochondrial permeability transition pore

Intracerebral hemorrhage (ICH) is the second most common subtype of stroke, characterized by high mortality and a poor prognosis. Despite various treatment methods, there has been limited improvement in the prognosis of ICH over the past decades. Therefore, it is imperative to identify a feasible treatment strategy for ICH. Mitochondria are organelles present in most eukaryotic cells and serve as the primary sites for aerobic respiration and energy production. Under unfavorable cellular conditions, mitochondria can induce changes in permeability through the opening of the mitochondrial permeability transition pore (mPTP), ultimately leading to mitochondrial dysfunction and contributing to various diseases. Recent studies have demonstrated that mPTP plays a role in the pathological processes associated with several neurodegenerative diseases including Parkinson's disease, Alzheimer's disease, Huntington's disease, ischemic stroke and ischemia-reperfusion injury, among others. However, there is limited research on mPTP involvement specifically in ICH. Therefore, this study comprehensively examines the pathological processes associated with mPTP in terms of oxidative stress, apoptosis, necrosis, autophagy, ferroptosis, and other related mechanisms to elucidate the potential mechanism underlying mPTP involvement in ICH. This research aims to provide novel insights for the treatment of secondary injury after ICH.

Targeting brain-peripheral immune responses for secondary brain injury after ischemic and hemorrhagic stroke

The notion that the central nervous system is an immunologically immune-exempt organ has changed over the past two decades, with increasing evidence of strong links and interactions between the central nervous system and the peripheral immune system, both in the healthy state and after ischemic and hemorrhagic stroke. Although primary injury after stroke is certainly important, the limited therapeutic efficacy, poor neurological prognosis and high mortality have led researchers to realize that secondary injury and damage may also play important roles in influencing long-term neurological prognosis and mortality and that the neuroinflammatory process in secondary injury is one of the most important influences on disease progression. Here, we summarize the interactions of the central nervous system with the peripheral immune system after ischemic and hemorrhagic stroke, in particular, how the central nervous system activates and recruits peripheral immune components, and we review recent advances in corresponding therapeutic approaches and clinical studies, emphasizing the importance of the role of the peripheral immune system in ischemic and hemorrhagic stroke.

Integrated Network Pharmacology and in vivo Experimental Validation Approach to Explore the Potential Antioxidant Effects of Annao Pingchong Decoction in Intracerebral Hemorrhage Rats

Background

Annao Pingchong decoction (ANPCD) is a traditional Chinese decoction which has definite effects on treating intracerebral hemorrhage (ICH) validated through clinical and experimental studies. However, the impact of ANPCD on oxidative stress (OS) after ICH remains unclear and is worth further investigating.

Aim

To investigate whether the therapeutic effects of ANPCD on ICH are related to alleviating OS damage and seek potential targets for its antioxidant effects.

Materials and Methods

The therapeutic candidate genes of ANPCD on ICH were identified through a comparison of the target genes of ANPCD, target genes of ICH and differentially expressed genes (DEGs). Protein-protein interaction (PPI) network analysis and functional enrichment analysis were combined with targets-related literature to select suitable antioxidant targets. The affinity between ANPCD and the selected target was verified using macromolecular docking. Subsequently, the effects of ANPCD on OS and the selected target were further investigated through in vivo experiments.

Results

Forty-eight candidate genes were screened, in which silent information regulator sirtuin 1 (SIRT1) is one of the core genes that has antioxidant effects and ICH significantly affected its expression. The good affinity between 6 compounds of ANPCD and SIRT1 was also demonstrated by macromolecular docking. The results of in vivo experiments demonstrated that ANPCD significantly decreased modified neurological severity scoring (mNSS) scores and serum MDA and 8-OHdG content in ICH rats, while significantly increasing serum SOD and CAT activity, complicated with the up-regulation of ANPCD on SIRT1, FOXO1, PGC-1α and Nrf2. Furthermore, ANPCD significantly decreased the apoptosis rate and the expression of apoptosis-related proteins (P53, cytochrome c and caspase-3).

Conclusion

ANPCD alleviates OS damage and apoptosis after ICH in rats. As a potential therapeutic target, SIRT1 can be effectively regulated by ANPCD, as are its downstream proteins.

A novel strategy of integrating network pharmacology and transcriptome reveals antiapoptotic mechanisms of Buyang Huanwu Decoction in treating intracerebral hemorrhage

ETHNOPHARMACOLOGICAL RELEVANCE

Buyang Huanwu Decoction (BYHWD), as a traditional Chinese medical prescription, has been used to treat intracerebral hemorrhage (ICH) for hundreds of years, but the antiapoptotic properties have not yet been studied.

AIM OF THE STUDY

This study aims to elucidate the antiapoptotic mechanism of BYHWD in ICH.

MATERIALS AND METHODS

The therapeutic effect of BYHWD on ICH was assessed by modified neurological severity scores (mNSS), foot fault, and histopathological staining. Then, we used a modified comprehensive strategy by integrating transcriptome and network pharmacology to reveal the underlying mechanism. TUNEL assay, qRT-PCR, and western blot were further applied to evaluate the antiapoptotic effect of BYHWD on ICH. Dual-luciferase reporter assay and plasmid transfections were implemented to validate the potential competing endogenous RNAs (ceRNA) mechanism of Sh2b3.

RESULTS

Network pharmacology analysis indicated that the regulation of the apoptotic process was the highest enriched GO term, and that MAP kinase activity, ERK1, and ERK2 cascade were strongly correlated. Transcriptome analysis screened 180 differentially expressed mRNAs, which were highly enriched in the immune system process and negative regulation of programmed cell death. By checking the literature, we found that Sh2b3 was of great importance to apoptosis by modulating MAPK cascades. TUNEL assay validated the anti-apoptotic effect of BYHWD. Moreover, BYHWD was proven to regulate the Sh2b3-mediated ERK1/2 signaling pathway in ICH mice by qRT-PCR and western blot. We further explored the lncRNA-miRNA-mRNA network underlying the therapeutic effect, among which 4933404O12Rik/miR-185-5p is the upstream regulatory mechanism of Sh2b3.

CONCLUSIONS

We explored the antiapoptotic mechanism of BYHWD in treating ICH by a novel integrated strategy, which involved the 4933404O12Rik/miR-185-5p/Sh2b3 ceRNAs axis.

Antioxidant Dimethyl Fumarate Temporarily but Not Chronically Improves Intracortical Microelectrode Performance

Intracortical microelectrode arrays (MEAs) can be used in a range of applications, from basic neuroscience research to providing an intimate interface with the brain as part of a brain-computer interface (BCI) system aimed at restoring function for people living with neurological disorders or injuries. Unfortunately, MEAs tend to fail prematurely, leading to a loss in functionality for many applications. An important contributing factor in MEA failure is oxidative stress resulting from chronically inflammatory-activated microglia and macrophages releasing reactive oxygen species (ROS) around the implant site. Antioxidants offer a means for mitigating oxidative stress and improving tissue health and MEA performance. Here, we investigate using the clinically available antioxidant dimethyl fumarate (DMF) to reduce the neuroinflammatory response and improve MEA performance in a rat MEA model. Daily treatment of DMF for 16 weeks resulted in a significant improvement in the recording capabilities of MEA devices during the sub-chronic (Weeks 5-11) phase (42% active electrode yield vs. 35% for control). However, these sub-chronic improvements were lost in the chronic implantation phase, as a more exacerbated neuroinflammatory response occurs in DMF-treated animals by 16 weeks post-implantation. Yet, neuroinflammation was indiscriminate between treatment and control groups during the sub-chronic phase. Although worse for chronic use, a temporary improvement (<12 weeks) in MEA performance is meaningful. Providing short-term improvement to MEA devices using DMF can allow for improved use for limited-duration studies. Further efforts should be taken to explore the mechanism behind a worsened neuroinflammatory response at the 16-week time point for DMF-treated animals and assess its usefulness for specific applications.

Role of lipocalin 2 in stroke

Stroke is the second leading cause of death worldwide; however, the treatment choices available to neurologists are limited in clinical practice. Lipocalin 2 (LCN2) is a secreted protein, belonging to the lipocalin superfamily, with multiple biological functions in mediating innate immune response, inflammatory response, iron-homeostasis, cell migration and differentiation, energy metabolism, and other processes in the body. LCN2 is expressed at low levels in the brain under normal physiological conditions, but its expression is significantly up-regulated in multiple acute stimulations and chronic pathologies. An up-regulation of LCN2 has been found in the blood/cerebrospinal fluid of patients with ischemic/hemorrhagic stroke, and could serve as a potential biomarker for the prediction of the severity of acute stroke. LCN2 activates reactive astrocytes and microglia, promotes neutrophil infiltration, amplifies post-stroke inflammation, promotes blood-brain barrier disruption, white matter injury, and neuronal death. Moreover, LCN2 is involved in brain injury induced by thrombin and erythrocyte lysates, as well as microvascular thrombosis after hemorrhage. In this paper, we review the role of LCN2 in the pathological processes of ischemic stroke; intracerebral hemorrhage; subarachnoid hemorrhage; and stroke-related brain diseases, such as vascular dementia and post-stroke depression, and their underlying mechanisms. We hope that this review will help elucidate the value of LCN2 as a therapeutic target in stroke.

Network Pharmacology Prediction and Experimental Verification for Anti-Ferroptosis of Edaravone After Experimental Intracerebral Hemorrhage

Neuronal ferroptosis plays an important role in secondary brain injuries after intracerebral hemorrhage (ICH). Edaravone (Eda) is a promising free radical scavenger that inhibits ferroptosis in neurological diseases. However, its protective effects and underlying mechanisms in ameliorating post-ICH ferroptosis remain unclear. We employed a network pharmacology approach to determine the core targets of Eda against ICH. Forty-two rats were subjected to successful striatal autologous whole blood injection (n=28) or sham operation (n=14). The 28 blood-injected rats were randomly assigned to either the Eda or vehicle group (n=14) for immediate administration and then for 3 consecutive days. Hemin-induced HT22 cells were used for in vitro studies. The effects of Eda in ICH on ferroptosis and the MEK/ERK pathway were investigated in vivo and in vitro. Network pharmacology-based analysis revealed that candidate targets of Eda-treated ICH might be related to ferroptosis; among which prostaglandin G/H synthase 2 (PTGS2) was a ferroptosis marker. In vivo experiments showed that Eda alleviated sensorimotor deficits and decreased PTGS2 expression (all p<0.05) after ICH. Eda rescued neuron pathological changes after ICH (increased NeuN⁺ cells and decreased FJC⁺ cells, all p<0.01). In vitro experiments showed that Eda reduced intracellular reactive oxygen species and reversed mitochondria damage. Eda repressed ferroptosis by decreasing malondialdehyde and iron deposition and by influencing ferroptosis-related protein expression (all p<0.05) in ICH rats and hemin-induced HT22 cells. Mechanically, Eda significantly suppressed phosphorylated-MEK and phosphorylated-ERK1/2 expression. These results indicate that Eda has protective effects on ICH injury through ferroptosis and MEK/ERK pathway suppression.

Potential role of IGF-1/GLP-1 signaling activation in intracerebral hemorrhage

IGF-1 and GLP-1 receptors are essential in all tissues, facilitating defense by upregulating anabolic processes. They are abundantly distributed throughout the central nervous system, promoting neuronal proliferation, survival, and differentiation. IGF-1/GLP-1 is a growth factor that stimulates neurons' development, reorganization, myelination, and survival. In primary and secondary brain injury, the IGF-1/GLP-1 receptors are impaired, resulting in further neuro complications such as cerebral tissue degradation, neuroinflammation, oxidative stress, and atrophy. Intracerebral hemorrhage (ICH) is a severe condition caused by a stroke for which there is currently no effective treatment. While some pre-clinical studies and medications are being developed as symptomatic therapies in clinical trials, there are specific pharmacological implications for improving post-operative conditions in patients with intensive treatment. Identifying the underlying molecular process and recognizing the worsening situation can assist researchers in developing effective therapeutic solutions to prevent post-hemorrhagic symptoms and the associated neural dysfunctions. As a result, in the current review, we have addressed the manifestations of the disease that are aggravated by the downregulation of IGF-1 and GLP-1 receptors, which can lead to ICH or other neurodegenerative disorders. Our review summarizes that IGF-1/GLP-1 activators may be useful for treating ICH and its related neurodegeneration.

Optimizing the Time Window of Minimally Invasive Stereotactic Surgery for Intracerebral Hemorrhage Evacuation Combined with Rosiglitazone Infusion Therapy in Rabbits

OBJECTIVE

This study aimed to explore the effects of minimally invasive surgery (MIS) in combination with rosiglitazone (RSG) on intracerebral hemorrhage (ICH) and determine the optimal time window.

METHODS

An ICH rabbit model was constructed using the injection of autologous arterial blood and then treated with RSG, MIS, and MIS combined with RSG at 6, 12, 18, and 24 hours. Thereafter, rabbits that underwent different treatments were used to measure the neurological deficit score, brain water content, and glutamate content. Expression of peroxisome proliferator-activated receptor γ (PPARγ) and CD36 in the different groups was detected using real-time quantitative polymerase chain reaction and Western blotting. In addition, oxidative stress-related and inflammation-related genes were examined.

RESULTS

Brain computed tomography indicated that an ICH rabbit model was successfully established. Compared to those in the control rabbits, the neurological deficit scores, brain water content, and glutamate content in the ICH rabbits were significantly increased at each time window (P < 0.05), while they were decreased at each time window after MIS combined with RSG treatment and declined to the lowest at 6 hours. Additionally, ICH significantly upregulated PPARγ and CD36 expression (P < 0.05). Moreover, superoxide dismutase content decreased after ICH, and nitric oxide synthase 2, tumor necrosis factor-alpha, interleukin-6, and interleukin-1 beta mRNA expression was upregulated, whereas MIS combined with RSG treatment reversed the levels caused by ICH.

CONCLUSIONS

Evacuation of MIS hematoma combined with RSG infusion at an early stage (6 hours) may attenuate secondary brain damage caused by ICH by regulating the PPARγ/CD36 pathway.

Secondary Brain Injury by Oxidative Stress After Cerebral Hemorrhage: Recent Advances

Intracerebral hemorrhage (ICH) is a clinical syndrome in which blood accumulates in the brain parenchyma because of a nontraumatic rupture of a blood vessel. Because of its high morbidity and mortality rate and the lack of effective therapy, the treatment of ICH has become a hot research topic. Meanwhile, Oxidative stress is one of the main causes of secondary brain injury(SBI) after ICH. Therefore, there is a need for an in-depth study of oxidative stress after ICH. This review will discuss the pathway and effects of oxidative stress after ICH and its relationship with inflammation and autophagy, as well as the current antioxidant therapy for ICH with a view to deriving better therapeutic tools or targets for ICH.

The Role of Mitochondrial Dynamin in Stroke

Stroke is one of the leading causes of death and disability in the world. However, the pathophysiological process of stroke is still not fully clarified. Mitochondria play an important role in promoting nerve survival and are an important drug target for the treatment of stroke. Mitochondrial dysfunction is one of the hallmarks of stroke. Mitochondria are in a state of continuous fission and fusion, which are termed as mitochondrial dynamics. Mitochondrial dynamics are very important for maintaining various functions of mitochondria. In this review, we will introduce the structure and functions of mitochondrial fission and fusion related proteins and discuss their role in the pathophysiologic process of stroke. A better understanding of mitochondrial dynamin in stroke will pave way for the development of new therapeutic options.

Oxidative Stress Following Intracerebral Hemorrhage: From Molecular Mechanisms to Therapeutic Targets

Intracerebral hemorrhage (ICH) is a highly fatal disease with mortality rate of approximately 50%. Oxidative stress (OS) is a prominent cause of brain injury in ICH. Important sources of reactive oxygen species after hemorrhage are mitochondria dysfunction, degradated products of erythrocytes, excitotoxic glutamate, activated microglia and infiltrated neutrophils. OS harms the central nervous system after ICH mainly through impacting inflammation, killing brain cells and exacerbating damage of the blood brain barrier. This review discusses the sources and the possible molecular mechanisms of OS in producing brain injury in ICH, and anti-OS strategies to ameliorate the devastation of ICH.

The Influence of Oxidative Stress on Neurological Outcomes in Spontaneous Intracerebral Hemorrhage

Spontaneous intracerebral hemorrhage (ICH) causes, besides the primary brain injury, a secondary brain injury (SBI), which is induced, amongst other things, by oxidative stress (OS) and inflammation, determining the patient's outcome. This study aims to assess the impact of OS in plasma and cerebrospinal fluid (CSF) on clinical outcomes in patients with ICH. A total of 19 ICH (volume > 30 cc) patients and 29 control patients were included. From day one until seven, blood and CSF samples were obtained, and ICH volume was calculated. OS markers, like malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione-sulfhydryl (GSH), and the total antioxidant status (TAS) were measured. Clinical data on treatment and outcome were determined. Patients with mRS ≤ 4 showed significantly elevated SOD and GSH-Px levels in plasma compared to patients with poor CO (p = 0.004; p = 0.002). Initial increased TAS in plasma and increased MDA in CSF were linked to an unfavorable outcome after six months (p = 0.06, r = 0.45; p = 0.05, r = 0.44). A higher ICH volume was associated with a worse outcome at week six (p = 0.04, r = 0.47). OS plays a significant role in SBI. Larger ICHs, elevated MDA in CSF, and TAS in plasma were associated with a detrimental outcome, whereas higher plasma-SOD and -GSH-Px were associated with a favorable outcome.

Acrolein Aggravates Secondary Brain Injury After Intracerebral Hemorrhage Through Drp1-Mediated Mitochondrial Oxidative Damage in Mice

Clinical advances in the treatment of intracranial hemorrhage (ICH) are restricted by the incomplete understanding of the molecular mechanisms contributing to secondary brain injury. Acrolein is a highly active unsaturated aldehyde which has been implicated in many nervous system diseases. Our results indicated a significant increase in the level of acrolein after ICH in mouse brain. In primary neurons, acrolein induced an increase in mitochondrial fragmentation, loss of mitochondrial membrane potential, generation of reactive oxidative species, and release of mitochondrial cytochrome c. Mechanistically, acrolein facilitated the translocation of dynamin-related protein1 (Drp1) from the cytoplasm onto the mitochondrial membrane and led to excessive mitochondrial fission. Further studies found that treatment with hydralazine (an acrolein scavenger) significantly reversed Drp1 translocation and the morphological damage of mitochondria after ICH. In parallel, the neural apoptosis, brain edema, and neurological functional deficits induced by ICH were also remarkably alleviated. In conclusion, our results identify acrolein as an important contributor to the secondary brain injury following ICH. Meanwhile, we uncovered a novel mechanism by which Drp1-mediated mitochondrial oxidative damage is involved in acrolein-induced brain injury.

Activating PPARγ Increases NQO1 and γ-GCS Expression via Nrf2 in Thrombin-activated Microglia

The present study aimed to explore the molecular mechanisms underlying the increase of nicotinamide adenine dinucleotide phosphate:quinine oxidoreductase 1 (NQO1) and γ-glutamylcysteine synthetase (γ-GCS) in brain tissues after intracerebral hemorrhage (ICH). The microglial cells obtained from newborn rats were cultured and then randomly divided into the normal control group (NC group), model control group (MC group), rosiglitazone (RSG) intervention group (RSG group), retinoic-acid intervention group (RSG+RA group), and sulforaphane group (RSG+SF group). The expression levels of NQO1, γ-GCS, and nuclear factor E2-related factor 2 (Nrf2) were measured by real-time polymerase chain reaction (RT-PCR) and Western blotting, respectively. The results showed that the levels of NQO1, γ-GCS and Nrf2 were significantly increased in the MC group and the RSG group as compared with those in the NC group (P<0.01). They were found to be markedly decreased in the RSG+RA group and increased in the RSG+SF group when compared with those in the MC group or the RSG group (P<0.01). The RSG+SF group displayed the highest levels of NQO1, γ-GCS, and Nrf2 among the five groups. In conclusion, a medium dose of RSG increased the anti-oxidative ability of thrombin-activated microglia by increasing the expression of NQO1 and γ-GCS. The molecular mechanisms underlying the increase of NQO1 and γ-GCS in thrombin-activated microglia may be associated with the activation of Nrf2.

Intracerebral Hemorrhage: Blood Components and Neurotoxicity

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

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.

Remote ischemic post-conditioning promotes hematoma resolution via AMPK-dependent immune regulation

Spontaneous intracerebral hemorrhage (ICH) produces the highest acute mortality and worst outcomes of all stroke subtypes. Hematoma volume is an independent determinant of ICH patient outcomes, making clot resolution a primary goal of clinical management. Herein, remote-limb ischemic post-conditioning (RIC), the repetitive inflation-deflation of a blood pressure cuff on a limb, accelerated hematoma resolution and improved neurological outcomes after ICH in mice. Parabiosis studies revealed RIC accelerated clot resolution via a humoral-mediated mechanism. Whereas RIC increased anti-inflammatory macrophage activation, myeloid cell depletion eliminated the beneficial effects of RIC after ICH. Myeloid-specific inactivation of the metabolic regulator, AMPKα1, attenuated RIC-induced anti-inflammatory macrophage polarization and delayed hematoma resolution, providing a molecular link between RIC and immune activation. Finally, chimera studies implicated myeloid CD36 expression in RIC-mediated neurological recovery after ICH. Thus, RIC, a clinically well-tolerated therapy, noninvasively modulates innate immune responses to improve ICH outcomes. Moreover, immunometabolic changes may provide pharmacodynamic blood biomarkers to clinically monitor the therapeutic efficacy of RIC.

Rosiglitazone pretreatment influences thrombin-induced anti-oxidative action via activating NQO1and γ-GCS in rat microglial cells

Objective To explore the molecular mechanism involved in rosiglitazone against secondary brain damage caused by cerebral hemorrhage, we pretreated thrombin-induced microglial cells by rosiglitazone and then investigated its effect on antioxidant-related genes NQO1and γ-GCS expression change. Methods Primary microglial cells were obtained from the brain tissue of newborn Sprague-Dawley (SD) rats and were randomly divided into three groups: the normal (control), thrombin stimulation (TH), thrombin-treated plus rosiglitazone (TH+RGZ). The expression of NQO1and γ-GCS was measured by immunocytochemistry, real-time PCR, and western blot analysis. Results The immunocytochemistry showed that the number of NQO1and γ-GCS stained cells in TH and TH+RGZ group increased compared to the control group. In addition, the expression of NQO1 and γ-GCS in TH+RGZ group remarkably increased in mRNA and protein level compared to TH only group (p < 0.01). Conclusion Rosiglitazone can increase thrombin-induced microglia anti-oxidative ability by increasing NQO1and γ-GCS expression, which can effectively reduce secondary injury after cerebral hemorrhage.

Treatment Strategies to Attenuate Perihematomal Edema in Patients With Intracerebral Hemorrhage

Spontaneous intracerebral hemorrhage (SICH) continues to be a significant cause of neurologic morbidity and mortality throughout the world. Although recent advances in the treatment of SICH have significantly decreased mortality rates, functional recovery has not been dramatically improved by any intervention to date. There are 2 predominant mechanisms of brain injury from intracerebral hemorrhage: mechanical injury from the primary hematoma (including growth of that hematoma), and secondary injury from perihematomal inflammation. For instance, in the hours to weeks after SICH as the hematoma is being degraded, thrombin and iron are released and can result in neurotoxicity, free radical damage, dysregulated coagulation, and harmful inflammatory cascades; this can clinically and radiologically manifest as perihematomal edema (PHE). PHE can contribute to mass effect, cause acute neurologic deterioration in patients, and has even been associated with poor long-term functional outcomes. PHE therefore lends itself to being a potential therapeutic target. In this article, we will review 1) the pathogenesis and time course of the development of PHE, and 2) the clinical series and trials exploring various methods, with a focus on minimally invasive surgical techniques, to reduce PHE and minimize secondary brain injury. Promising areas of continued research also will be discussed.

The Injury and Therapy of Reactive Oxygen Species in Intracerebral Hemorrhage Looking at Mitochondria

Intracerebral hemorrhage is an emerging major health problem often resulting in death or disability. Reactive oxygen species (ROS) have been identified as one of the major damaging factors in ischemic stroke. However, there is less discussion about ROS in hemorrhage stroke. Metabolic products of hemoglobin, excitatory amino acids, and inflammatory cells are all sources of ROS, and ROS harm the central nervous system through cell death and structural damage, especially disruption of the blood-brain barrier. We have considered the antioxidant system of the CNS itself and the drugs aiming to decrease ROS after ICH, and we find that mitochondria are key players in all of these aspects. Moreover, when the mitochondrial permeability transition pore opens, ROS-induced ROS release, which leads to extensive liberation of ROS and mitochondrial failure, occurs. Therefore, the mitochondrion may be a significant target for elucidating the problem of ROS in ICH; however, additional experimental support is required.

Intracerebral Hemorrhage, Oxidative Stress, and Antioxidant Therapy

Hemorrhagic stroke is a common and severe neurological disorder and is associated with high rates of mortality and morbidity, especially for intracerebral hemorrhage (ICH). Increasing evidence demonstrates that oxidative stress responses participate in the pathophysiological processes of secondary brain injury (SBI) following ICH. The mechanisms involved in interoperable systems include endoplasmic reticulum (ER) stress, neuronal apoptosis and necrosis, inflammation, and autophagy. In this review, we summarized some promising advances in the field of oxidative stress and ICH, including contained animal and human investigations. We also discussed the role of oxidative stress, systemic oxidative stress responses, and some research of potential therapeutic options aimed at reducing oxidative stress to protect the neuronal function after ICH, focusing on the challenges of translation between preclinical and clinical studies, and potential post-ICH antioxidative therapeutic approaches.

Effects of Danhong Injection (丹红注射液) and its main components on anticoagulation and fibrinolysis in cultured vein endothelial cells

OBJECTIVE

To observe the effects of Danhong Injection (丹红注射液) and its main components, including daiclzein and hydroxysafflor yellow A (HSYA), on the anticoagulation, fibrinolysis, anti-apoptosis in hypoxia model of vein endothelial cells (VECs).

METHODS

VECs were prepared and were put in a hypoxia environment, which consisted of mixed gas of 95% N and 5% CO mixed gas, when reached confluent culture. Five groups used different treatments, including normal control group, hypoxia group, daiclzein group, HSYA group and Danhong Injection group. The VECs were identified by fluorescence double labeling methods. The morphology was observed by a phase contrast microscopy. The effects of Danhong Injection, daiclzein and HSYA on 6 keto prostaglandin F1α (6-keto-PGF1α) level was measured by the method of radioimmunoassay (RIA). Superoxide dismutase (SOD) activity was tested by water soluble tetrazolium salt. The content of malondialdehyde (MDA) was measured by thiobarbituric acid. The activities of tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) were measured by the method of chromogenic substrate. The contents of endothelin (ET) and nitric oxide (NO) were detected by non-equilibrium RIA and enzymelinked immunosorbent assay. Cells apoptosis rate was determined by flow cytometry.

RESULTS

Compared with the normal control group, the floating cells number, PAI activity, ET and MDA contents, and cells apoptosis rate in the culture solution of hypoxia group were all significantly increased, whereas the 6-keto-PGF1α and NO contents, and t-PA and SOD activities were decreased significantly (P<0.01). Compared with the hypoxia group, Danhong Injection markedly increased the 6-keto-PGF1α content and SOD activity, regulated PAI and t-PA activities, ET and NO contents, and decreased MDA content and cells apoptosis rate (P<0.05 or P<0.01).

CONCLUSIONS

Danhong Injection and its main components played an important role in protecting primary VECs from hypoxic damage by regulating the secretion and vasomotor function of VECs. The function of Danhong Injection was most remarkable.

Oxidative Stress in Intracerebral Hemorrhage: Sources, Mechanisms, and Therapeutic Targets

Intracerebral hemorrhage (ICH) is associated with the highest mortality and morbidity despite only constituting approximately 10–15% of all strokes. Complex underlying mechanisms consisting of cytotoxic, excitotoxic, and inflammatory effects of intraparenchymal blood are responsible for its highly damaging effects. Oxidative stress (OS) also plays an important role in brain injury after ICH but attracts less attention than other factors. Increasing evidence has demonstrated that the metabolite axis of hemoglobin-heme-iron is the key contributor to oxidative brain damage after ICH, although other factors, such as neuroinflammation and prooxidases, are involved. This review will discuss the sources, possible molecular mechanisms, and potential therapeutic targets of OS in ICH.

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

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

Neuroinflammation after intracerebral hemorrhage

Spontaneous intracerebral hemorrhage (ICH) is a particularly severe type of stroke for which no specific treatment has been established yet. Although preclinical models of ICH have substantial methodological limitations, important insight into the pathophysiology has been gained. Mounting evidence suggests an important contribution of inflammatory mechanisms to brain damage and potential repair. Neuroinflammation evoked by intracerebral blood involves the activation of resident microglia, the infiltration of systemic immune cells and the production of cytokines, chemokines, extracellular proteases and reactive oxygen species (ROS). Previous studies focused on innate immunity including microglia, monocytes and granulocytes. More recently, the role of adaptive immune cells has received increasing attention. Little is currently known about the interactions among different immune cell populations in the setting of ICH. Nevertheless, immunomodulatory strategies are already being explored in ICH. To improve the chances of translation from preclinical models to patients, a better characterization of the neuroinflammation in patients is desirable.

New avenues for treatment of intracranial hemorrhage

OPINION STATEMENT

The mortality and morbidity from intracerebral hemorrhage (ICH) remain high despite advances in medical, neurologic, and surgical care during the past decade. The lessons learned from previous therapeutic trials in ICH, improved understanding of the pathophysiology of neuronal injury after ICH, and advances in imaging and pre-hospital assessment technologies provide optimism that more effective therapies for ICH are likely to emerge in the coming years. The potential new avenues for the treatment of ICH include a combination of increased utilization of minimally invasive surgical techniques with or without thrombolytic usage to evacuate or reduce the size of the hematoma; utilization of advanced imaging to improve selection of patients who are likely to benefit from reversal of coagulopathy or hemostatic therapy; ultra-early diagnosis and initiation of therapy in the ambulance; and the use of novel drugs to target the secondary injury mechanisms, including the inflammatory cascade, perihematomal edema reduction, and hemoglobin degradation products-mediated toxicity.

Involvement of GMRP1, a novel mediator of Akt pathway, in brain damage after intracerebral hemorrhage

GMRP1, also known as BTBD10, has been reported to inhibit apoptosis of neuronal and islet beta cells via Akt pathway. The present study attempted to investigate whether GMRP1 and its mediated Akt pathway were involved in brain injury of rats after intracerebral hemorrhage (ICH). Rat models of ICH had been established successfully. Western blotting was used to investigate the levels of GMRP1 protein in caudate nuclei tissues of hemorrhagic and contralateral sides at 6 h, day 1, day 3, day 5, day 7 after ICH. Phosphorylation of Akt was determined in caudate nuclei mentioned above. TUNEL assay was used to measure the cell apoptosis. GMRP1 protein levels, as well as phosphorylations of Akt, significantly decreased in caudate nuclei of hemorrhagic side, compared with those of contralateral side at day 1, day 3 after ICH. Enhanced cell apoptosis was observed in hemorrhagic side by TUNEL assay. We presented here evidence that decreased GMRP1-mediated Akt pathway contributed to cell apoptosis in hemorrhagic side, suggesting that GMRP1 played an important role in brain damage after ICH.

Early changes in GMRP1 after intracerebral hemorrhage: involvement in brain damage and cell apoptosis

Glucose metabolism-related protein 1 (GMRP1), also known as BTBD10, has been reported to inhibit apoptosis of neuronal and islet beta cells via the Akt pathway. The present study attempted to investigate whether GMRP1 and its mediated Akt pathway were involved in brain injury of rats after intracerebral hemorrhage (ICH). Rat models of ICH had been established successfully. Western blotting was used to investigate the levels of GMRP1 protein in the caudate nuclei tissues of the hemorrhagic and contralateral sides at 6 h, day 1, day 3, day 5, and day 7 after ICH. Phosphorylations of Akt was determined in caudate nuclei mentioned above. TUNEL assay was used to measure the cell apoptosis. GMRP1 protein levels, as well as phosphorylations of Akt, significantly decreased in caudate nuclei of the hemorrhagic side, compared with those of the contralateral side on day 1 and day 3 after ICH. Enhanced cell apoptosis was observed on the hemorrhagic side using TUNEL assay. We presented here evidence that a decreased GMRP1-mediated Akt pathway contributed to cell apoptosis on the hemorrhagic side, suggesting that GMRP1 plays an important role in brain damage after ICH.

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.

Relationship between cellular apoptosis and the expression of p75 neurotrophin receptor and tyrosine kinase A receptor in tissue surrounding haematoma in intracerebral haemorrhage

Cellular apoptosis and the expression of p75 neurotrophin receptor (p75(NTR)) and tyrosine kinase A receptor (TrkA) were investigated in the tissues surrounding haematoma in patients with intracerebral haemorrhage. Specimens of tissue from near the haematoma (haemorrhagic samples) and tissue from a distant site (control samples) were collected from 14 patients with basal ganglia haemorrhage undergoing surgical intervention. Cellular apoptosis was determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelling (TUNEL), and p75(NTR) and TrkA location, protein and gene expression were studied using immunohistochemistry, Western blot and real-time polymerase chain reaction, respectively. The percentage of apoptotic cells and expression of p75(NTR), but not of TrkA, were significantly higher in the haemorrhagic samples than in the control samples. There was a positive correlation between the percentage of TUNEL-positive cells and the percentage of p75(NTR)-positive cells. These results suggest that the p75(NTR)-dependent signal transduction pathway plays an important role in apoptosis after intracerebral haemorrhage.

Edaravone protects against apoptotic neuronal cell death and improves cerebral function after traumatic brain injury in rats

Edaravone is a novel free radical scavenger used clinically in patients with acute cerebral infarction; however, it has not been assessed in traumatic brain injury (TBI). We investigated the effects of edaravone on cerebral function and morphology following TBI. Rats received TBI with a pneumatic controlled injury device. Edaravone (3 mg/kg) or physiological saline was administered intravenously following TBI. Numbers of 8-OHdG-, 4-HNE-, and ssDNA-positive cells around the damaged area after TBI were significantly decreased in the edaravone group compared with the saline group (P < 0.01). There was a significant increase in neuronal cell number and improvement in cerebral dysfunction after TBI in the edaravone group compared with the saline group (P < 0.01). Edaravone administration following TBI inhibited free radical-induced neuronal degeneration and apoptotic cell death around the damaged area. In summary, edaravone treatment improved cerebral dysfunction following TBI, suggesting its potential as an effective clinical therapy.