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

Hypothermia protects the integrity of corticospinal tracts and alleviates mitochondria injury after intracerebral hemorrhage in mice

Disruption of corticospinal tracts (CST) is a leading factor for motor impairments following intracerebral hemorrhage (ICH) in the striatum. Previous studies have shown that therapeutic hypothermia (HT) improves outcomes of ICH patients. However, whether HT has a direct protection effect on the CST integrity and the underlying mechanisms remain largely unknown. In this study, we employed a chemogenetics approach to selectively activate bilateral warm-sensitive neurons in the preoptic areas to induce a hypothermia-like state. We then assessed effects of HT treatment on the integrity of CST and motor functional recovery after ICH. Our results showed that HT treatment significantly alleviated axonal degeneration around the hematoma and the CST axons at remote midbrain region, ultimately promoted skilled motor function recovery. Anterograde and retrograde tracing revealed that HT treatment protected the integrity of the CST over an extended period. Mechanistically, HT treatment prevented mitochondrial swelling in degenerated axons around the hematoma, alleviated mitochondrial impairment by reducing mitochondrial ROS accumulation and improving mitochondrial membrane potential in primarily cultured cortical neurons with oxyhemoglobin treatment. Serving as a proof of principle, our study provided novel insights into the application of HT to improve functional recovery after ICH.

Icariin improves oxidative stress injury during ischemic stroke via inhibiting mPTP opening

BACKGROUND

Ischemic stroke presents a significant threat to human health due to its high disability rate and mortality. Currently, the clinical treatment drug, rt-PA, has a narrow therapeutic window and carries a high risk of bleeding. There is an urgent need to find new effective therapeutic drugs for ischemic stroke. Icariin (ICA), a key ingredient in the traditional Chinese medicine Epimedium, undergoes metabolism in vivo to produce Icaritin (ICT). While ICA has been reported to inhibit neuronal apoptosis after cerebral ischemia-reperfusion (I/R), yet its underlying mechanism remains unclear.

METHODS

PC-12 cells were treated with 200 µM H2O2 for 8 h to establish a vitro model of oxidative damage. After administration of ICT, cell viability was detected by Thiazolyl blue tetrazolium Bromide (MTT) assay, reactive oxygen species (ROS) and apoptosis level, mPTP status and mitochondrial membrane potential (MMP) were detected by flow cytometry and immunofluorescence. Apoptosis and mitochondrial permeability transition pore (mPTP) related proteins were assessed by Western blotting. Middle cerebral artery occlusion (MCAO) model was used to establish I/R injury in vivo. After the treatment of ICA, the neurological function was scored by ZeaLonga socres; the infarct volume was observed by 2,3,5-Triphenyltetrazolium chloride (TTC) staining; HE and Nissl staining were used to detect the pathological state of the ischemic cortex; the expression changes of mPTP and apoptosis related proteins were detected by Western blotting.

RESULTS

In vitro: ICT effectively improved H2O2-induced oxidative injury through decreasing the ROS level, inhibiting mPTP opening and apoptosis. In addition, the protective effects of ICT were not enhanced when it was co-treated with mPTP inhibitor Cyclosporin A (CsA), but reversed when combined with mPTP activator Lonidamine (LND). In vivo: Rats after MCAO shown cortical infarct volume of 32-40%, severe neurological impairment, while mPTP opening and apoptosis were obviously increased. Those damage caused was improved by the administration of ICA and CsA.

CONCLUSIONS

ICA improves cerebral ischemia-reperfusion injury by inhibiting mPTP opening, making it a potential candidate drug for the treatment of ischemic stroke.

The Role of Oxidative Stress in the Progression of Secondary Brain Injury Following Germinal Matrix Hemorrhage

Germinal matrix hemorrhage (GMH) can be a fatal condition responsible for the death of 1.7% of all neonates in the USA. The majority of GMH survivors develop long-term sequalae with debilitating comorbidities. Higher grade GMH is associated with higher mortality rates and higher prevalence of comorbidities. The pathophysiology of GMH can be broken down into two main titles: faulty hemodynamic autoregulation and structural weakness at the level of tissues and cells. Prematurity is the most significant risk factor for GMH, and it predisposes to both major pathophysiological mechanisms of the condition. Secondary brain injury is an important determinant of survival and comorbidities following GMH. Mechanisms of brain injury secondary to GMH include apoptosis, necrosis, neuroinflammation, and oxidative stress. This review will have a special focus on the mechanisms of oxidative stress following GMH, including but not limited to inflammation, mitochondrial reactive oxygen species, glutamate toxicity, and hemoglobin metabolic products. In addition, this review will explore treatment options of GMH, especially targeted therapy.

Biological role of mitochondrial TLR4-mediated NF-κB signaling pathway in central nervous system injury

Previous studies suggested that central nervous system injury is often accompanied by the activation of Toll-like receptor 4/NF-κB pathway, which leads to the upregulation of proapoptotic gene expression, causes mitochondrial oxidative stress, and further aggravates the inflammatory response to induce cell apoptosis. Subsequent studies have shown that NF-κB and IκBα can directly act on mitochondria. Therefore, elucidation of the specific mechanisms of NF-κB and IκBα in mitochondria may help to discover new therapeutic targets for central nervous system injury. Recent studies have suggested that NF-κB (especially RelA) in mitochondria can inhibit mitochondrial respiration or DNA expression, leading to mitochondrial dysfunction. IκBα silencing will cause reactive oxygen species storm and initiate the mitochondrial apoptosis pathway. Other research results suggest that RelA can regulate mitochondrial respiration and energy metabolism balance by interacting with p53 and STAT3, thus initiating the mitochondrial protection mechanism. IκBα can also inhibit apoptosis in mitochondria by interacting with VDAC1 and other molecules. Regulating the biological role of NF-κB signaling pathway in mitochondria by targeting key proteins such as p53, STAT3, and VDAC1 may help maintain the balance of mitochondrial respiration and energy metabolism, thereby protecting nerve cells and reducing inflammatory storms and death caused by ischemia and hypoxia.

Celastrol Ameliorates Neuronal Mitochondrial Dysfunction Induced by Intracerebral Hemorrhage via Targeting cAMP-Activated Exchange Protein-1

Mitochondrial dysfunction contributes to the development of secondary brain injury (SBI) following intracerebral hemorrhage (ICH) and represents a promising therapeutic target. Celastrol, the primary active component of Tripterygium wilfordii, is a natural product that exhibits mitochondrial and neuronal protection in various cell types. This study aims to investigate the neuroprotective effects of celastrol against ICH-induced SBI and explore its underlying mechanisms. Celastrol improves neurobehavioral and cognitive abilities in mice with autologous blood-induced ICH, reduces neuronal death in vivo and in vitro, and promotes mitochondrial function recovery in neurons. Single-cell nuclear sequencing reveals that the cyclic adenosine monophosphate (cAMP)/cAMP-activated exchange protein-1 (EPAC-1) signaling pathways are impacted by celastrol. Celastrol binds to cNMP (a domain of EPAC-1) to inhibit its interaction with voltage-dependent anion-selective channel protein 1 (VDAC1) and blocks the opening of mitochondrial permeability transition pores. After neuron-specific knockout of EPAC1, the neuroprotective effects of celastrol are diminished. In summary, this study demonstrates that celastrol, through its interaction with EPAC-1, ameliorates mitochondrial dysfunction in neurons, thus potentially improving SBI induced by ICH. These findings suggest that targeting EPAC-1 with celastrol can be a promising therapeutic approach for treating ICH-induced SBI.

Association between dietary total antioxidant capacity and the risk of stroke: a nested case-control study

BACKGROUND

Oxidative stress after ischemic stroke contribute to neuronal cell injury. Unhealthy and unbalanced dietary patterns can increase the risk of several diseases, including stroke and cardiometabolic ones. However, the association between dietary total antioxidant capacity (DTAC) of antioxidant and stroke is controversial. Our study aimed to establish a correlation between DTAC and its impact on the occurrence of stroke.

METHODS

This nested case-control study included 79 stroke cases and 158 healthy controls. We used data from the Fasa Adults Cohort Study (FACS) comprising 10,035 individuals at baseline. To assess the nutritional status of each individual, a 125-item food frequency questionnaire (FFQ) has been used to evaluate their dietary habits and intakes over the past year. DTAC was calculated using the ferric-reducing antioxidant power (FRAP) international databases. The stroke was confirmed by an experienced neurologist using standard imaging methods. Conditional logistic regression analyses were performed to evaluate the association between DTAC and stroke.

RESULTS

The assessment of DTAC revealed that there was no statistically significant distinction between cases (mean ± SD: 5.31 ± 2.65) and controls (5.16 ± 2.80) with a p-value of 0.95. Even after adjusting for the potentially important confounding factors such as age, sex, event time, energy intake, smoking, hypertension, and diabetes, the association remains non-significant (adjusted odds ratio (OR) = 1.06, 95% CI: 0.94, 1.20, p-value = 0.33).

CONCLUSIONS

Our results did not confirm a significant link between DTAC and stroke risk. These findings emphasize the intricate interplay of factors influencing stroke risk and highlight the need for further research to unravel these relationships more comprehensively.

Mitophagy in intracerebral hemorrhage: a new target for therapeutic intervention

Intracerebral hemorrhage is a life-threatening condition with a high fatality rate and severe sequelae. However, there is currently no treatment available for intracerebral hemorrhage, unlike for other stroke subtypes. Recent studies have indicated that mitochondrial dysfunction and mitophagy likely relate to the pathophysiology of intracerebral hemorrhage. Mitophagy, or selective autophagy of mitochondria, is an essential pathway to preserve mitochondrial homeostasis by clearing up damaged mitochondria. Mitophagy markedly contributes to the reduction of secondary brain injury caused by mitochondrial dysfunction after intracerebral hemorrhage. This review provides an overview of the mitochondrial dysfunction that occurs after intracerebral hemorrhage and the underlying mechanisms regarding how mitophagy regulates it, and discusses the new direction of therapeutic strategies targeting mitophagy for intracerebral hemorrhage, aiming to determine the close connection between mitophagy and intracerebral hemorrhage and identify new therapies to modulate mitophagy after intracerebral hemorrhage. In conclusion, although only a small number of drugs modulating mitophagy in intracerebral hemorrhage have been found thus far, most of which are in the preclinical stage and require further investigation, mitophagy is still a very valid and promising therapeutic target for intracerebral hemorrhage in the long run.

Connection between oxidative stress and subcellular organelle in subarachnoid hemorrhage: Novel mechanisms and therapeutic implications

Spontaneous subarachnoid hemorrhage (SAH) is one of the most devastating forms of stroke, with limited treatment modalities and poor patient outcomes. Previous studies have proposed multiple prognostic factors; however, relative research on treatment has not yet yielded favorable clinical outcomes. Moreover, recent studies have suggested that early brain injury (EBI) occurring within 72 h after SAH may contribute to its poor clinical outcomes. Oxidative stress is recognized as one of the main mechanisms of EBI, which causes damage to various subcellular organelles, including the mitochondria, nucleus, endoplasmic reticulum (ER), and lysosomes. This could lead to significant impairment of numerous cellular functions, such as energy supply, protein synthesis, and autophagy, which may directly contribute to the development of EBI and poor long-term prognostic outcomes. In this review, the mechanisms underlying the connection between oxidative stress and subcellular organelles after SAH are discussed, and promising therapeutic options based on these mechanisms are summarized.

The Neuroprotective Effects and Probable Mechanisms of Everolimus in a Rat Model of Intracerebral Hemorrhage

Mammalian target of rapamycin (mTOR) is a central regulator of cellular growth and homeostasis. Changes in mTOR activity are often observed in many neurological diseases, such as stroke. Intracerebral hemorrhage (ICH) is associated with high mortality and morbidity. However, there are currently no treatments that have been shown to enhance outcomes following ICH, so new treatments are urgently required. In this study, a selective mTOR inhibitor, everolimus, was applied to investigate the outcome after ICH and the possible underlying mechanism. The ICH model was established by autologous blood injection. Everolimus (50 and 100 µg/kg) was administered intraperitoneally for 14 consecutive days' post-operation. The neurological functions were examined at 3, 7, and 14 days' post-ICH. Samples of brain tissue were collected to perform histopathological and immunohistochemical (NF-k-positive cell) examinations. Besides, the striatum was used to evaluate parameters related to oxidative stress (superoxide dismutase (SOD) activity, malondialdehyde (MDA), and total thiol levels) and inflammation markers (TNF-α and NO). Everolimus ameliorated ICH-induced neurological deficits. In addition, treatment with everolimus reduced infarct volume and NF-k-β positive cells as compared to the ICH group. Furthermore, everolimus significantly increased total thiol content and SOD activity while significantly reducing MDA, NO, and TNF- levels as compared to the ICH group. Collectively, our investigation showed that everolimus improves ICH outcome and modulates oxidative stress and inflammation after ICH. Treatment with rapamycin reduced neurological deficient, oxidative stress, and inflammation in a rat model of intracerebral hemorrhage.

Targeting redox imbalance in neurodegeneration: characterizing the role of GLP-1 receptor agonists

Reactive oxygen species (ROS) have emerged as essential signaling molecules regulating cell survival, death, inflammation, differentiation, growth, and immune response. Environmental factors, genetic factors, or many pathological condition such as diabetes increase the level of ROS generation by elevating the production of advanced glycation end products, reducing free radical scavengers, increasing mitochondrial oxidative stress, and by interfering with DAG-PKC-NADPH oxidase and xanthine oxidase pathways. Oxidative stress, and therefore the accumulation of intracellular ROS, determines the deregulation of several proteins and caspases, damages DNA and RNA, and interferes with normal neuronal function. Furthermore, ROS play an essential role in the polymerization, phosphorylation, and aggregation of tau and amyloid-beta, key mediators of cognitive function decline. At the neuronal level, ROS interfere with the DNA methylation pattern and various apoptotic factors related to cell death, promoting neurodegeneration. Only few drugs are able to quench ROS production in neurons. The cross-linking pathways between diabetes and dementia suggest that antidiabetic medications can potentially treat dementia. Among antidiabetic drugs, glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been found to reduce ROS generation and ameliorate mitochondrial function, protein aggregation, neuroinflammation, synaptic plasticity, learning, and memory. The incretin hormone glucagon-like peptide-1 (GLP-1) is produced by the enteroendocrine L cells in the distal intestine after food ingestion. Upon interacting with its receptor (GLP-1R), it regulates blood glucose levels by inducing insulin secretion, inhibiting glucagon production, and slowing gastric emptying. No study has evidenced a specific GLP-1RA pathway that quenches ROS production. Here we summarize the effects of GLP-1RAs against ROS overproduction and discuss the putative efficacy of Exendin-4, Lixisenatide, and Liraglutide in treating dementia by decreasing ROS.

Pharmacological Inhibition of Ferroptosis as a Therapeutic Target for Neurodegenerative Diseases and Strokes

Emerging evidence suggests that ferroptosis, a unique regulated cell death modality that is morphologically and mechanistically different from other forms of cell death, plays a vital role in the pathophysiological process of neurodegenerative diseases, and strokes. Accumulating evidence supports ferroptosis as a critical factor of neurodegenerative diseases and strokes, and pharmacological inhibition of ferroptosis as a therapeutic target for these diseases. In this review article, the core mechanisms of ferroptosis are overviewed and the roles of ferroptosis in neurodegenerative diseases and strokes are described. Finally, the emerging findings in treating neurodegenerative diseases and strokes through pharmacological inhibition of ferroptosis are described. This review demonstrates that pharmacological inhibition of ferroptosis by bioactive small-molecule compounds (ferroptosis inhibitors) could be effective for treatments of these diseases, and highlights a potential promising therapeutic avenue that could be used to prevent neurodegenerative diseases and strokes. This review article will shed light on developing novel therapeutic regimens by pharmacological inhibition of ferroptosis to slow down the progression of these diseases in the future.

P7C3-A20 Attenuates Microglial Inflammation and Brain Injury after ICH through Activating the NAD+/Sirt3 Pathway

Intracerebral hemorrhage (ICH) is lethal but lacks effective therapies. Nicotinamide adenine dinucleotide (NAD⁺) is a central metabolite indispensable for a broader range of fundamental intracellular biological functions. Reduction of NAD⁺ usually occurs after acute brain insults, and supplementation of NAD⁺ has been proven neuroprotective. P7C3-A20 is a novel compound featuring its ability to facilitate the flux of NAD⁺. In this study, we sought to determine the potential therapeutic value of P7C3-A20 in ICH. In collagenase-induced ICH mouse models, we found that P7C3-A20 treatment could diminish lesion volume, reduce blood-brain barrier (BBB) damage, mitigate brain edema, attenuate neural apoptosis, and improve neurological outcomes after ICH. Further, RNA sequencing and subsequent experiments revealed that ICH-induced neuroinflammation and microglial proinflammatory activities were significantly suppressed following P7C3-A20 treatment. Mitochondrial damage is an important trigger of inflammatory response. We examined mitochondrial morphology and function and found that P7C3-A20 could attenuate OxyHb-induced impairment of mitochondrial dynamics and functions in vitro. Mechanistically, Sirt3, an NAD⁺-dependent deacetylase located in mitochondria, was then found to play a vital role in the protection of P7C3-A20 against mitochondrial damage and inflammatory response. In rescue experiments, P7C3-A20 failed to exert those protective effects in microglia-specific Sirt3 conditional knockout (CKO) mice. Finally, preclinical research revealed a correlation between the plasma NAD⁺ level and the neurological outcome in ICH patients. These results demonstrate that P7C3-A20 is a promising therapeutic agent for neuroinflammatory injury after ICH and exerts protective actions, at least partly, in a Sirt3-dependent manner.

Endothelial cell TRPA1 activity exacerbates cerebral hemorrhage during severe hypertension

Introduction: Hypoxia-induced dilation of cerebral arteries orchestrated by Ca2+-permeable transient receptor potential ankyrin 1 (TRPA1) cation channels on endothelial cells is neuroprotective during ischemic stroke, but it is unknown if the channel has a similar impact during hemorrhagic stroke. TRPA1 channels are endogenously activated by lipid peroxide metabolites generated by reactive oxygen species (ROS). Uncontrolled hypertension, a primary risk factor for the development of hemorrhagic stroke, is associated with increased ROS production and oxidative stress. Therefore, we hypothesized that TRPA1 channel activity is increased during hemorrhagic stroke. Methods: Severe, chronic hypertension was induced in control (Trpa1 fl/fl) and endothelial cell-specific TRPA1 knockout (Trpa1-ecKO) mice using a combination of chronic angiotensin II administration, a high-salt diet, and the addition of a nitric oxide synthase inhibitor to drinking water. Blood pressure was measured in awake, freely-moving mice using surgically placed radiotelemetry transmitters. TRPA1-dependent cerebral artery dilation was evaluated with pressure myography, and expression of TRPA1 and NADPH oxidase (NOX) isoforms in arteries from both groups was determined using PCR and Western blotting techniques. In addition, ROS generation capacity was evaluated using a lucigenin assay. Histology was performed to examine intracerebral hemorrhage lesion size and location. Results: All animals became hypertensive, and a majority developed intracerebral hemorrhages or died of unknown causes. Baseline blood pressure and responses to the hypertensive stimulus did not differ between groups. Expression of TRPA1 in cerebral arteries from control mice was not altered after 28 days of treatment, but expression of three NOX isoforms and the capacity for ROS generation was increased in hypertensive animals. NOX-dependent activation of TRPA1 channels dilated cerebral arteries from hypertensive animals to a greater extent compared with controls. The number of intracerebral hemorrhage lesions in hypertensive animals did not differ between control and Trpa1-ecKO animals but were significantly smaller in Trpa1-ecKO mice. Morbidity and mortality did not differ between groups. Discussion: We conclude that endothelial cell TRPA1 channel activity increases cerebral blood flow during hypertension resulting in increased extravasation of blood during intracerebral hemorrhage events; however, this effect does not impact overall survival. Our data suggest that blocking TRPA1 channels may not be helpful for treating hypertension-associated hemorrhagic stroke in a clinical setting.

Two Argan Oil Phytosterols, Schottenol and Spinasterol, Attenuate Oxidative Stress and Restore LPS-Dysregulated Peroxisomal Functions in Acox1-/- and Wild-Type BV-2 Microglial Cells

Oxidative stress and inflammation are the key players in neuroinflammation, in which microglia dysfunction plays a central role. Previous studies suggest that argan oil attenuates oxidative stress, inflammation, and peroxisome dysfunction in mouse brains. In this study, we explored the effects of two major argan oil (AO) phytosterols, Schottenol (Schot) and Spinasterol (Spina), on oxidative stress, inflammation, and peroxisomal dysfunction in two murine microglial BV-2 cell lines, wild-ype (Wt) and Acyl-CoA oxidase 1 (Acox1)-deficient cells challenged with LPS treatment. Herein, we used an MTT test to reveal no cytotoxicity for both phytosterols with concentrations up to 5 µM. In the LPS-activated microglial cells, cotreatment with each of these phytosterols caused a significant decrease in intracellular ROS production and the NO level released in the culture medium. Additionally, Schot and Spina were able to attenuate the LPS-dependent strong induction of Il-1β and Tnf-α mRNA levels, as well as the iNos gene and protein expression in both Wt and Acox1-/- microglial cells. On the other hand, LPS treatment impacted both the peroxisomal antioxidant capacity and the fatty acid oxidation pathway. However, both Schot and Spina treatments enhanced ACOX1 activity in the Wt BV-2 cells and normalized the catalase activity in both Wt and Acox1-/- microglial cells. These data suggest that Schot and Spina can protect cells from oxidative stress and inflammation and their harmful consequences for peroxisomal functions and the homeostasis of microglial cells. Collectively, our work provides a compelling argument for the protective mechanisms of two major argan oil phytosterols against LPS-induced brain neuroinflammation.

Stroke: Molecular mechanisms and therapies: Update on recent developments

Stroke, a neurological disease, is one of the leading causes of death worldwide, resulting in long-term disability in most survivors. Annual stroke costs in the United States alone were estimated at $46 billion recently. Stroke pathophysiology is complex, involving multiple causal factors, among which atherosclerosis, thrombus, and embolus are prevalent. The molecular mechanisms involved in the pathophysiology are essential to understanding targeted drug development. Some common mechanisms are excitotoxicity and calcium overload, oxidative stress, and neuroinflammation. In addition, various modifiable and non-modifiable risk factors increase the chances of stroke manifolds. Once a patient encounters a stroke, complete restoration of motor ability and cognitive skills is often rare. Therefore, shaping therapeutic strategies is paramount for finding a viable therapeutic agent. Apart from tPA, an FDA-approved therapy that is applied in most stroke cases, many other therapeutic strategies have been met with limited success. Stroke therapies often involve a combination of multiple strategies to restore the patient's normal function. Certain drugs like Gamma-aminobutyric receptor agonists (GABA), Glutamate Receptor inhibitors, Sodium, and Calcium channel blockers, and fibrinogen-depleting agents have shown promise in stroke treatment. Recently, a drug, DM199, a recombinant (synthetic) form of a naturally occurring protein called human tissue kallikrein-1 (KLK1), has shown great potential in treating stroke with fewer side effects. Furthermore, DM199 has been found to overcome the limitations presented when using tPA and/or mechanical thrombectomy. Cell-based therapies like Neural Stem Cells, Hematopoietic stem cells (HSCs), and Human umbilical cord blood-derived mesenchymal stem cells (HUCB-MSCs) are also being explored as a treatment of choice for stroke. These therapeutic agents come with merits and demerits, but continuous research and efforts are being made to develop the best therapeutic strategies to minimize the damage post-stroke and restore complete neurological function in stroke patients.

The Role of Mitochondria-Targeting miRNAs in Intracerebral Hemorrhage

Non-traumatic intracerebral hemorrhage (ICH) is the most common type of hemorrhagic stroke, most often occurring between the ages of 45 and 60. Arterial hypertension (AH) is most often the cause of ICH, followed by atherosclerosis, blood diseases, inflammatory changes in cerebral vessels, intoxication and vitamin deficiencies. Cerebral hemorrhage can occur by diapedesis or as a result of a ruptured vessel. AH is difficult to treat, requires surgery and can lead to disability or death. One of the important directions in the study of the pathogenesis of ICH is mitochondrial dysfunction and its regulation. The key role of mitochondrial dysfunction in AH and atherosclerosis, as well as in the development of brain damage after hemorrhage, has been acknowledged. MicroRNAs (miRNAs) are a class of non-coding RNAs (about 18-22 nucleotides) that regulate a variety of biological processes including cell differentiation, proliferation, apoptosis, etc., primarily through gene repression. There is growing evidence to support dysregulated miRNAs in various cardiovascular diseases, including ICH. Further, the realization of miRNAs within mitochondrial compartment has challenged the traditional knowledge of signaling pathways involved in the regulatory network of cardiovascular diseases. However, the role of miRNAs in mitochondrial dysfunction for ICH is still under-appreciated, with comparatively much lesser studies and investigations reported, than those in other cardiovascular diseases. In this review, we summarize the up-to-date findings on the published role miRNAs in mitochondrial function for ICH, and the potential use of miRNAs in clinical settings, such as potential therapeutic targets and non-invasive diagnostic/prognostic biomarker tools.

Advancement of epigenetics in stroke

A wide plethora of intervention procedures, tissue plasminogen activators, mechanical thrombectomy, and several neuroprotective drugs were reported in stroke research over the last decennium. However, against this vivid background of newly emerging pieces of evidence, there is little to no advancement in the overall functional outcomes. With the advancement of epigenetic tools and technologies associated with intervention medicine, stroke research has entered a new fertile. The stroke involves an overabundance of inflammatory responses arising in part due to the body's immune response to brain injury. Neuroinflammation contributes to significant neuronal cell death and the development of functional impairment and even death in stroke patients. Recent studies have demonstrated that epigenetics plays a key role in post-stroke conditions, leading to inflammatory responses and alteration of the microenvironment within the injured tissue. In this review, we summarize the progress of epigenetics which provides an overview of recent advancements on the emerging key role of secondary brain injury in stroke. We also discuss potential epigenetic therapies related to clinical practice.

Transplantation of Astrocytic Mitochondria Modulates Neuronal Antioxidant Defense and Neuroplasticity and Promotes Functional Recovery after Intracerebral Hemorrhage

Astrocytes release functional mitochondria (Mt) that play regulatory and prosurvival functions on entering adjacent cells. We recently demonstrated that these released Mts could enter microglia to promote their reparative/prophagocytic phenotype that assists in hematoma cleanup and neurological recovery after intracerebral hemorrhage (ICH). However, the relevance of astrocytic Mt transfer into neurons in protecting brain after ICH is unclear. Here, we found that ICH causes a robust increase in superoxide generation and elevated oxidative damage that coincides with loss of the mitochondrial enzyme manganese superoxide dismutase (Mn-SOD). The damaging effect of ICH was reversed by intravenous transplantation of astrocytic Mt, which on entering the brain (and neurons), restored Mn-SOD levels and reduced neurological deficits in male mice subjected to ICH. Using an in vitro ICH-like injury model in cultured neurons, we established that astrocytic Mt on entering neurons prevented reactive oxygen species-induced oxidative stress and neuronal death by restoring neuronal Mn-SOD levels while at the same time promoted neurite extension and upregulation of synaptogenesis-related gene expression. Furthermore, we found that Mt genome-encoded small peptide humanin, which is normally abundant in Mt, could simulate Mt-transfer effect on neuronal Mn-SOD expression, oxidative stress, and neuroplasticity under ICH-like injury. This study demonstrates that adoptive astrocytic Mt transfer enhances neuronal Mn-SOD-mediated antioxidative defense and neuroplasticity in the brain, which potentiate functional recovery following ICH.SIGNIFICANCE STATEMENT Mitochondrial dysfunction and antioxidant defense play essential roles in brain damage after ICH. Astrocytes release functional Mt that enters adjacent cells to help brain homeostatic function. Here, we show that systemic transplantation of astrocytic Mt restores ICH-impaired neuronal antioxidative defense, enhances neurite outgrowth, and improves stroke recovery after ICH. Our study suggests that systemic transplantation of astrocytic Mt could be considered as a novel and potentially promising strategy for ICH treatment.

The Effect of Polyphenols on Kidney Disease: Targeting Mitochondria

Mitochondrial function, including oxidative phosphorylation (OXPHOS), mitochondrial biogenesis, and mitochondria dynamics, are essential for the maintenance of renal health. Through modulation of mitochondrial function, the kidneys are able to sustain or recover acute kidney injury (AKI), chronic kidney disease (CKD), nephrotoxicity, nephropathy, and ischemia perfusion. Therapeutic improvement in mitochondrial function in the kidneys is related to the regulation of adenosine triphosphate (ATP) production, free radicals scavenging, decline in apoptosis, and inflammation. Dietary antioxidants, notably polyphenols present in fruits, vegetables, and plants, have attracted attention as effective dietary and pharmacological interventions. Considerable evidence shows that polyphenols protect against mitochondrial damage in different experimental models of kidney disease. Mechanistically, polyphenols regulate the mitochondrial redox status, apoptosis, and multiple intercellular signaling pathways. Therefore, this review attempts to focus on the role of polyphenols in the prevention or treatment of kidney disease and explore the molecular mechanisms associated with their pharmacological activity.

Emerging Mechanisms and Targeted Therapy of Ferroptosis in Neurological Diseases and Neuro-oncology

Ferroptosis is a novel type of cell death characterized by iron-dependent lipid peroxidation that involves a variety of biological processes, such as iron metabolism, lipid metabolism, and oxidative stress. A growing body of research suggests that ferroptosis is associated with cancer and neurodegenerative diseases, such as glioblastoma, Alzheimer's disease, Parkinson's disease, and stroke. Building on these findings, we can selectively induce ferroptosis for the treatment of certain cancers, or we can treat neurodegenerative diseases by inhibiting ferroptosis. This review summarizes the relevant advances in ferroptosis, the regulatory mechanisms of ferroptosis, the participation of ferroptosis in brain tumors and neurodegenerative diseases, and the corresponding drug therapies to provide new potential targets for its treatment.

Energy Metabolism on Mitochondrial Maturation and Its Effects on Cardiomyocyte Cell Fate

Alterations in energy metabolism play a major role in the lineage of cardiomyocytes, such as the dramatic changes that occur in the transition from neonate to newborn. As cardiomyocytes mature, they shift from a primarily glycolytic state to a mitochondrial oxidative metabolic state. Metabolic intermediates and metabolites may have epigenetic and transcriptional roles in controlling cell fate by increasing mitochondrial biogenesis. In the maturing cardiomyocyte, such as in the postnatal heart, fatty acid oxidation increases in conjunction with increased mitochondrial biogenesis driven by the transcriptional coregulator PGC1-α. PGC1-α is necessary for mitochondrial biogenesis in the heart at birth, with deficiencies leading to postnatal cardiomyopathy. While stem cell therapy as a treatment for heart failure requires further investigation, studies suggest that adult stem cells may secrete cardioprotective factors which may regulate cardiomyocyte differentiation and survival. This review will discuss how metabolism influences mitochondrial biogenesis and how mitochondrial biogenesis influences cell fate, particularly in the context of the developing cardiomyocyte. The implications of energy metabolism on stem cell differentiation into cardiomyocytes and how this may be utilized as a therapy against heart failure and cardiovascular disease will also be discussed.

Targeting Oxidative Stress and Inflammatory Response for Blood-Brain Barrier Protection in Intracerebral Hemorrhage

Significance: Blood-brain barrier (BBB) disruption is a major pathological change after intracerebral hemorrhage (ICH) and is both the cause and result of oxidative stress and of the immune response post-ICH. These processes contribute to ICH-induced brain injury. Recent Advances: After the breakdown of cerebral vessels, blood components, including erythrocytes and their metabolites, thrombin, and fibrinogen, can access the cerebral parenchyma through the compromised BBB, triggering oxidative stress and inflammatory cascades. These aggravate BBB disruption and contribute to further infiltration of blood components, resulting in a vicious cycle that exacerbates brain edema and neurological injury after ICH. Experimental and clinical studies have highlighted the role of BBB disruption in ICH-induced brain injury. Critical Issues: In this review, we focus on the strategies to protect the BBB in ICH. Specifically, we summarize the evidence and the underlying mechanisms, including the ICH-induced process of oxidative stress and inflammatory response, and we highlight the potential therapeutic targets to protect BBB integrity after ICH. Future Directions: Future studies should probe the mechanism of ferroptosis as well as oxidative stress-inflammation coupling in BBB disruption after ICH and investigate the effects of antioxidants and immunomodulatory agents in more ICH clinical trials. Antioxid. Redox Signal. 37, 115-134.

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.

Rational Design of a Theranostic Agent Triggered by Endogenous Nitric Oxide in a Cellular Model of Alzheimer's Disease

Oxidative damage caused by upregulated nitric oxide (NO) plays an important role in the pathogenesis of Alzheimer's disease (AD). Currently, stimulus-triggered theranostic agents have received much attention due to benefits on disease imaging and targeted therapeutic effects. However, the development of a theranostic agent triggered by NO for AD remains unexplored. Herein, through the mechanism analysis of the reaction between a fluorophore of 9,14-diphenyl-9,14-dihydrodibenzo[a,c]phenazine (DPAC) and NO, which we occasionally found and thereafter structure optimization of DPAC, a theranostic agent DPAC-(peg)₄-memantine was fabricated. In an AD cellular model, DPAC-(peg)₄-memantine exhibits NO sensing ability for AD imaging. Meanwhile, DPAC-(peg)₄-memantine shows improved therapeutic by targeted drug release triggered by NO and sustained therapeutic effects owing to the synergetic antioxidative abilities via the anti-AD drug and NO scavenging. This work provides an unprecedented avenue for the studies on not only AD but also other diseases with NO upregulation.

Artemisinin upregulates neural cell adhesion molecule L1 to attenuate neurological deficits after intracerebral hemorrhage in mice

BACKGROUND AND PURPOSE

Intracerebral hemorrhage (ICH) is a subtype of stroke and results in neurological deficits in patients without any effective treatments. Artemisinin (ART), a well-known antimalarial Chinese medicine, exerts multiple essential roles in the central and peripheral nervous system due to its antioxidative and anti-inflammation properties. Neural cell adhesion molecule L1 (L1CAM, L1) is considered to be implicated in neural development, functional maintenance, and neuroprotection during disease. However, whether these two essential molecules are neuroprotective in ICH remains unclear.

METHODS

Therefore, the present study investigated the influence of ART on the recovery of neurological deficits in a mouse model of ICH induced by collagenase and the underlying mechanism.

RESULTS

It was revealed that ART is capable of upregulating L1 expression to alleviate brain edema, reduce oxidative stress, and inhibit inflammation to alleviate ICH-induced brain injury to improve the neurological outcome in mice suffering from ICH.

CONCLUSION

These results may lay the foundation for ART to be a novel candidate treatment for ICH.

Targeting the multifaceted roles of mitochondria in intracerebral hemorrhage and therapeutic prospects

Intracerebral hemorrhage (ICH) is a severe, life-threatening subtype of stoke that constitutes a crucial health and socioeconomic problem worldwide. However, the current clinical treatment can only reduce the mortality of patients to a certain extent, but cannot ameliorate neurological dysfunction and has a high recurrence rate. Increasing evidence has demonstrated that mitochondrial dysfunction occurs in the early stages of brain injury and participates in all stages of secondary brain injury (SBI) after ICH. As the energy source of cells, various pathobiological processes that lead to SBI closely interact with the mitochondria, such as oxidative stress, calcium overload, and neuronal injury. In this review, we discussed the structure and function of mitochondria and the abnormal morphological changes after ICH. In addition, we discussed recent research on the involvement of mitochondrial dynamics in the pathological process of SBI after ICH and introduced the pathological variations and related molecular mechanisms of mitochondrial dysfunction in the occurrence of brain injury. Finally, we summarized the latest progress in mitochondrion-targeted agents for ICH, which provides a direction for the development of emerging therapeutic strategies targeting the mitochondria after ICH.

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.

Sevoflurane Improves Hemorrhagic Shock and Resuscitation-Induced Cognitive Impairments and Mitochondrial Dysfunctions through SIRT1-Mediated Autophagy

Cerebral ischemia reperfusion injury (IRI) induced by hemorrhagic shock and reperfusion (HSR) is the main cause of death following trauma. Previous studies indicated the neuroprotective effect of sevoflurane postconditioning (SP) in cerebral IRI. However, the mechanisms still remain elusive. Cerebral IRI models with SP were established by using HSR with C57BL/6 mice (male, 3-month-old) in vivo and by using oxygen glucose deprivation and reoxygenation (OGD/R) with HT22 cells in vitro. Postoperative cognition was evaluated by the Morris water maze, novel object recognition, and elevated plus maze tests. The role of SIRT1 was determined by using siRNA, a sensitive inhibitor (EX527), or an overexpression shRNA-GFP lentivirus. IRI caused significant disabilities of spatial learning and memory associated with enhanced cerebral infarct and neuronal apoptosis, which were effectively attenuated by SP. IRI also made a significant decrease of SIRT1 accompanied by oxidative stress, mitochondria dysfunction, and inactivated autophagy. SP or genetically overexpressing SIRT1 significantly suppressed defective autophagy, mitochondrial oxidative injury, and neuronal death caused by HSR or OGD/R. However, genetic suppression or pharmacological inhibition of SIRT1 significantly reversed the impact of SP treatment on mitochondrial DNA transcription ability and autophagy. Our results demonstrate that the loss of SIRT1 causes a sequential chain of mitochondrial dysfunction, defective autophagy, and neuronal apoptosis after IRI in the preclinical stroke models. Sevoflurane postconditioning treatment could effectively attenuate pathophysiological signatures induced by noxious stimuli, which maybe mediated by SIRT1.

The Novel Nrf2 Activator Omaveloxolone Regulates Microglia Phenotype and Ameliorates Secondary Brain Injury after Intracerebral Hemorrhage in Mice

The polarization of microglia is recognized as a crucial factor in reducing neuroinflammation and promoting hematoma clearance after intracerebral hemorrhage (ICH). Previous studies have revealed that redox components participate in the regulation of microglial polarization. Recently, the novel Nrf2 activator omaveloxolone (Omav) has been validated to improve neurological function in patients with neurodegenerative disorders by regulating antioxidant responses. In this study, we examined the efficacy of Omav in ICH. Omav significantly promoted Nrf2 nuclear accumulation and the expression of HO-1 and NQO1 in BV2 cells. In addition, both in vitro and in vivo experiments showed that Omav treatment inhibited M1-like activation and promoted the activation of the M2-like microglial phenotype. Omav inhibited OxyHb-induced ROS generation and preserved the function of mitochondria in BV2 cells. Intraperitoneal administration of Omav improved sensorimotor function in the ICH mouse model. Importantly, these effects were blocked by pretreatment with ML385, a selective inhibitor of Nrf2. Collectively, Omav modulated microglial polarization by activating Nrf2 and inhibiting ROS generation in ICH models, suggesting that it might be a promising drug candidate for the treatment of ICH.

Association of Maternal Diabetes and Autism Spectrum Disorders in Offspring: a Study in a Rodent Model of Autism

The present study investigated that maternal type 1 diabetes may contribute to autism pathogenesis in offspring, and that insulin therapy during pregnancy may prevent the onset of autism. As evidenced, selected brain biomarkers representing the accepted etiological mechanism of autism in newborn rats from diabetic mothers and diabetic mothers receiving insulin therapy compared to the propionic acid (PPA) rodent model of autism were screened. Female Wistar rats with a controlled fertility cycle were randomly divided into three groups: a control group, a group treated with a single dose of 65 mg/kg streptozotocin (STZ) to induce type 1 diabetes (T1D), and a group treated with a single dose of STZ to induce T1D along with insulin therapy. Neonatal rats from these groups were divided into four experimental groups of six animals each: the control group, oral buffered PPA-treated group administered a neurotoxic dose of 250 mg/kg PPA for 3 days to induce autism, neonatal rats from mothers with T1D, and neonatal rats from mothers with T1D receiving insulin therapy. Biochemical parameters of oxidative stress, neuroinflammation, and glutamate excitotoxicity were examined in brain homogenates from all neonatal rats. The development of pathogenic bacteria was monitored in stool samples from all rat groups. Descriptive analyses of changes in fecal microbiota and overgrowth of Clostridium species were performed in diabetic mothers, diabetic mothers treated with insulin therapy, and their offspring. Clostridium species may induce autism-relevant behaviors in offspring from mothers with T1D. Maternal T1D without insulin therapy increased lipid peroxidation levels, reduced GST activity, and lower offspring' vitamin C and GSH levels. Increased IL-6 levels and reduced GABA levels were detected in brain homogenates from neonatal rats whose mothers had T1D. Interestingly, insulin therapy reduced MDA and IL-6 levels and increased GST, GSH, and vitamin C levels in brain homogenates of neonatal rats from mothers with T1D receiving insulin therapy compared to the PPA-treated group. Based on our results, the PPA-treated group and neonatal rats from mothers with T1D exhibited similar results. These findings suggest that neonatal rats from mothers with T1D may develop autism-relevant biochemical autistic features and that insulin therapy may ameliorate oxidative stress, poor detoxification, inflammation, and excitotoxicity as ascertained mechanisms involved in the etiology of autism.

Mitochondrial Quality Control: A Pathophysiological Mechanism and Therapeutic Target for Stroke

Stroke is a devastating disease with high mortality and disability rates. Previous research has established that mitochondria, as major regulators, are both influenced by stroke, and further regulated the development of poststroke injury. Mitochondria are involved in several biological processes such as energy generation, calcium homeostasis, immune response, apoptosis regulation, and reactive oxygen species (ROS) generation. Meanwhile, mitochondria can evolve into various quality control systems, including mitochondrial dynamics (fission and fusion) and mitophagy, to maintain the homeostasis of the mitochondrial network. Various activities of mitochondrial fission and fusion are associated with mitochondrial integrity and neurological injury after stroke. Additionally, proper mitophagy seems to be neuroprotective for its effect on eliminating the damaged mitochondria, while excessive mitophagy disturbs energy generation and mitochondria-associated signal pathways. The balance between mitochondrial dynamics and mitophagy is more crucial than the absolute level of each process. A neurovascular unit (NVU) is a multidimensional system by which cells release multiple mediators and regulate diverse signaling pathways across the whole neurovascular network in a way with a high dynamic interaction. The turbulence of mitochondrial quality control (MQC) could lead to NVU dysfunctions, including neuron death, neuroglial activation, blood–brain barrier (BBB) disruption, and neuroinflammation. However, the exact changes and effects of MQC on the NVU after stroke have yet to be fully illustrated. In this review, we will discuss the updated mechanisms of MQC and the pathophysiology of mitochondrial dynamics and mitophagy after stroke. We highlight the regulation of MQC as a potential therapeutic target for both ischemic and hemorrhagic stroke.

Ferroptosis in Intracerebral Hemorrhage: A Panoramic Perspective of the Metabolism, Mechanism and Theranostics

Iron is one of the most crucial elements in the human body. In recent years, a kind of programmed, non-apoptotic cell death closely related to iron metabolism-called ferroptosis- has aroused much interest among many scientists. Ferroptosis also interacts with other pathways involved in cell death including iron abnormality, the cystine/glutamate antiporter and lipid peroxidation. Together these pathological pathways exert great impacts on intracerebral hemorrhage (ICH), a lethal cerebrovascular disease with a high incidence rate and mortality rate. Furthermore, the ferroptosis also affects different brain cells (neurons and neuroglial cells) and different organelles (mitochondria and endoplasmic reticulum). Clinical treatments for ferroptosis in ICH have been closely investigated recently. This perspective provides a comprehensive summary of ferroptosis mechanisms after ICH and its interaction with other cell death patterns. Understanding the role of ferroptosis in ICH will open new windows for the future treatments and preventions for ICH and other intracerebral diseases.

The critical role of glutathione redox homeostasis towards oxidation in ermanin-induced melanogenesis

Vitiligo is a depigmented disease featured as diagnosis simplicity and cure difficulty. Its occurrence and development are associated with a variety of factors, including oxidative stress, heredity and immunity, etc. Existing drugs for the treatment of vitiligo are to reduce the death of melanocytes and induce pigment accumulation as the main treatment strategy. Ermanin, a member of the flavonoids, is extracted from bee glue which is wildly used to treat vitiligo in traditional Chinese medicine. Therefore, this article discusses the relationship between melanogenesis and glutathione redox homeostasis by ermanin via biochemical and free radical approaches in vivo and in vitro. In this study, we found that ermanin effectively increased the melanin content at the in vivo model (zebrafish). Moreover, the melanin levels at the in vitro models (B16F10 cells and primary melanocytes) were also increased significantly accompanied with a shift of glutathione redox homeostasis towards oxidation. Ermanin also significantly enhanced the activity of tyrosinase. Meanwhile, ermanin increased the expression levels of TYR, TRP-1, and DCT genes, while ROS accumulation and glutathione depletion mediated the accumulation of pigments caused by ermanin, which increased the production of pigments and regulated the expression mRNA levels of TYR and DCT genes. From the perspective of pigment production regulation pathways, western blot showed that the pigment accumulation caused by ermanin was closely related to the CREB-MITF pathways, it activated CREB, TYR, TRP-1, and DCT proteins. The use of CREB specific inhibitor 666-15 and MITF inhibitor ML329 confirmed that the pigment accumulation caused by ermanin was positively correlated with CREB and MITF proteins. Our findings revealed the potential mechanisms by which ermanin promoted the production of melanin through activated CREB-MITF signaling pathway and glutathione redox homeostasis towards oxidation function as a signal are beneficial to melanin production and will help develop novel therapeutic approaches for vitiligo.

Microglia Phenotype and Intracerebral Hemorrhage: A Balance of Yin and Yang

Intracerebral hemorrhage (ICH) features extremely high rates of morbidity and mortality, with no specific and effective therapy. And local inflammation caused by the over-activated immune cells seriously damages the recovery of neurological function after ICH. Fortunately, immune intervention to microglia has provided new methods and ideas for ICH treatment. Microglia, as the resident immune cells in the brain, play vital roles in both tissue damage and repair processes after ICH. The perihematomal activated microglia not only arouse acute inflammatory responses, oxidative stress, excitotoxicity, and cytotoxicity to cause neuron death, but also show another phenotype that inhibit inflammation, clear hematoma and promote tissue regeneration. The proportion of microglia phenotypes determines the progression of brain tissue damage or repair after ICH. Therefore, microglia may be a promising and imperative therapeutic target for ICH. In this review, we discuss the dual functions of microglia in the brain after an ICH from immunological perspective, elaborate on the activation mechanism of perihematomal microglia, and summarize related therapeutic drugs researches.

Inflammation and Oxidative Stress: Potential Targets for Improving Prognosis After Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) has a high mortality rate and causes long-term disability in many patients, often associated with cognitive impairment. However, the pathogenesis of delayed brain dysfunction after SAH is not fully understood. A growing body of evidence suggests that neuroinflammation and oxidative stress play a negative role in neurofunctional deficits. Red blood cells and hemoglobin, immune cells, proinflammatory cytokines, and peroxidases are directly or indirectly involved in the regulation of neuroinflammation and oxidative stress in the central nervous system after SAH. This review explores the role of various cellular and acellular components in secondary inflammation and oxidative stress after SAH, and aims to provide new ideas for clinical treatment to improve the prognosis of SAH.

Upregulation of AQP4 Improves Blood-Brain Barrier Integrity and Perihematomal Edema Following Intracerebral Hemorrhage

In intracerebral hemorrhage (ICH), delayed secondary neural damages largely occur from perihematomal edema (PHE) resulting from the disruption of the blood-brain barrier (BBB). PHE is often considered the principal cause of morbidity and mortality in patients with ICH. Nevertheless, the main cellular mechanism as well as the specific BBB component involved in the formation of PHE after ICH remains elusive. Herein, we evaluated the role of AQP4, a water channel expressed on the astrocytes of the BBB, in the formation of PHE in ICH. The static and dynamic functions of the BBB were evaluated by analyzing the microstructure and leakage assay. Protein changes in the PHE lesion were analyzed and the control mechanism of AQP4 expression by reactive oxygen species was also investigated. Delayed PHE formation due to BBB disruption after ICH was confirmed by the decreased coverage of multiple BBB components and increased dynamic leakages. Microstructure assay showed that among the BBB components, AQP4 showed a markedly decreased expression in the PHE lesions. The decrease in AQP4 was due to microenvironmental ROS derived from the hemorrhage and was restored by treatment with ROS scavenger. AQP4-deficient mice had significantly larger PHE lesions and unfavorable survival outcomes compared with wild-type mice. Our data identify AQP4 as a specific BBB-modulating target for alleviating PHE in ICH. Further comprehensive studies are needed to form the preclinical basis for the use of AQP4 enhancers as BBB modulators for preventing delayed cerebral edema after ICH.

Natural products targeting mitochondria: emerging therapeutics for age-associated neurological disorders

Mitochondria are the primary source of energy production in the brain thereby supporting most of its activity. However, mitochondria become inefficient and dysfunctional with age and to a greater extent in neurological disorders. Thus, mitochondria represent an emerging drug target for many age-associated neurological disorders. This review summarizes recent advances (covering from 2010 to May 2020) in the use of natural products from plant, animal, and microbial sources as potential neuroprotective agents to restore mitochondrial function. Natural products from diverse classes of chemical structures are discussed and organized according to their mechanism of action on mitochondria in terms of modulation of biogenesis, dynamics, bioenergetics, calcium homeostasis, and membrane potential, as well as inhibition of the oxytosis/ferroptosis pathway. This analysis emphasizes the significant value of natural products for mitochondrial pharmacology as well as the opportunities and challenges for the discovery and development of future neurotherapeutics.

Zhuyu Annao decoction promotes angiogenesis in mice with cerebral hemorrhage by inhibiting the activity of PHD3

Some traditional Chinese decoctions, such as Zhuyu Annao, exert favorable therapeutic effects on acute cerebral hemorrhage, hemorrhagic stroke, and other neurological diseases, but the underlying mechanism remains unclear. This study aimed to determine whether Zhuyu Annao decoction (ZYAND) protects the injured brain by promoting angiogenesis following intracerebral hemorrhage (ICH) and elucidate its specific mechanism. The effect of ZYAND on the nervous system of mice after ICH was explored through behavioral experiments, such as the Morris water maze and Rotarod tests, and its effects on oxidative stress were explored by detecting several oxidative stress markers, including malondialdehyde, nitric oxide, glutathione peroxidase, and superoxide dismutase. Real-time quantitative RT-PCR and WB were used to detect the effects of ZYAND on the levels of prolyl hydroxylase domain 3 (PHD3), hypoxia-inducible factor-1α (HIF-1α), and vascular endothelial growth factor (VEGF) in the brain tissues of mice. The effect of ZYAND on the NF-κB signaling pathway was detected using a luciferase reporter gene. A human umbilical cord vascular endothelial cell angiogenesis experiment was performed to determine whether ZYAND promotes angiogenesis. The Morris water maze test and other behavioral experiments verified that ZYAND improved the neurobehavior of mice after ICH. ZYAND activated the PHD3/HIF-1α signaling pathway, inhibiting the oxidative damage caused by ICH. In angiogenesis experiments, it was found that ZYAND promoted VEGF-induced angiogenesis by upregulating the expression of HIF-1α, and NF-κB signaling regulated the expression of HIF-1α by inhibiting PHD3. ZYAND exerts a reparative effect on brain tissue damaged after ICH through the NF-κB/ PHD3/HIF-1α/VEGF signaling axis.

Mesenchymal Stem Cells Transplantation in Intracerebral Hemorrhage: Application and Challenges

Intracerebral hemorrhage (ICH) is one of the leading causes of death and long-term disability worldwide. Mesenchymal stem cell (MSC) therapies have demonstrated improved outcomes for treating ICH-induced neuronal defects, and the neural network reconstruction and neurological function recovery were enhanced in rodent ICH models through the mechanisms of neurogenesis, angiogenesis, anti-inflammation, and anti-apoptosis. However, many key issues associated with the survival, differentiation, and safety of grafted MSCs after ICH remain to be resolved, which hinder the clinical translation of MSC therapy. Herein, we reviewed an overview of the research status of MSC transplantation after ICH in different species including rodents, swine, monkey, and human, and the challenges for MSC-mediated ICH recovery from pathological microenvironment have been summarized. Furthermore, some efficient strategies for the outcome improvement of MSC transplantation were proposed.

Mechanisms of Oxidative Stress and Therapeutic Targets following Intracerebral Hemorrhage

Oxidative stress (OS) is induced by the accumulation of reactive oxygen species (ROS) following intracerebral hemorrhage (ICH) and plays an important role in secondary brain injury caused by the inflammatory response, apoptosis, autophagy, and blood-brain barrier (BBB) disruption. This review summarizes the current state of knowledge regarding the pathogenic mechanisms of brain injury after ICH, markers for detecting OS, and therapeutic strategies that target OS to mitigate brain injury.

GDF11 alleviates secondary brain injury after intracerebral hemorrhage via attenuating mitochondrial dynamic abnormality and dysfunction

Intracerebral hemorrhage (ICH) is a serious public health problem with high rates of death and disability. The neuroprotective effect of Growth Differentiation Factor 11 (GDF11) in ICH has been initially proved by our previous study. Oxidative stress (OS) plays crucial roles in mediating subsequent damage of ICH. However, whether and how mitochondrial dynamic events and function participated in ICH pathophysiology, and how mitochondrial function and OS interreacted in the neuroprotective process of GDF11 in ICH remains unclarified. Based on the rat model of ICH and in vitro cell model, we demonstrated that GDF11 could alleviate ICH induced neurological deficits, brain edema, OS status, neuronal apoptosis and inflammatory reaction. In addition, mitochondrial functional and structural impairments were obviously restored by GDF11. Treatment with antioxidant protected against erythrocyte homogenate (EH) induced cell injury by restoring OS status and mitochondrial fusion fission imbalance, which was similar to the effect of GDF11 treatment. Further, inhibition of mitochondrial division with Mdivi-1 attenuated mitochondrial functional defects and neuronal damages. In conclusion, our results for the first time proposed that GDF11 protected the post-ICH secondary injury by suppressing the feedback loop between mitochondrial ROS production and mitochondrial dynamic alteration, resulting in attenuated mitochondrial function and amelioration of neural damage.

A Selenium Nanocomposite Protects the Mouse Brain from Oxidative Injury Following Intracerebral Hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) is a common neurological crisis leading to high mortality and morbidity. Oxidative stress-induced secondary injury plays a critical role in neurological deterioration. Previously, we synthesized a porous Se@SiO2 nanocomposite and identified their therapeutic role in osteonecrosis of the femoral head. Whether this nanocomposite is neuroprotective remains to be elucidated.

METHODS

A porous Se@SiO2 nanocomposite was synthesized, and its biosafety was determined using a CCK-8 assay. The neuroprotective effect was evaluated by TUNEL staining, and intracellular ROS were detected with a DCFH-DA probe in SH-SY5Y cells exposed to hemin. Furthermore, the effect of the nanocomposite on cell apoptosis, brain edema and blood-brain barrier permeability were evaluated in a collagenase-induced ICH mouse model. The potential mechanism was also explored.

RESULTS

The results demonstrated that Se@SiO2 treatment significantly improved neurological function, increased glutathione peroxidase activity and downregulated malonaldehyde levels. The proportion of apoptotic cells, brain edema and blood-brain barrier permeability were reduced significantly in ICH mice treated with Se@SiO2 compared to vehicle-treated mice. In vitro, Se@SiO2 protected SH-SY5Y cells from hemin-induced apoptosis by preventing intracellular reactive oxygen species accumulation.

CONCLUSION

These results suggested that the porous Se@SiO2 nanocomposite exerted neuroprotection by suppressing oxidative stress. Se@SiO2 may be a potential candidate for the clinical treatment of ICH and oxidative stress-related brain injuries.

Mitochondria: Novel Mechanisms and Therapeutic Targets for Secondary Brain Injury After Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a destructive form of stroke that often results in death or disability. However, the survivors usually experience sequelae of neurological impairments and psychiatric disorders, which affect their daily functionality and working capacity. The recent MISTIE III and STICH II trials have confirmed that early surgical clearance of hematomas does not improve the prognosis of survivors of ICH, so it is vital to find the intervention target of secondary brain injury (SBI) after ICH. Mitochondrial dysfunction, which may be induced by oxidative stress, neuroinflammation, and autophagy, among others, is considered to be a novel pathological mechanism of ICH. Moreover, mitochondria play an important role in promoting neuronal survival and improving neurological function after a hemorrhagic stroke. This review summarizes the mitochondrial mechanism involved in cell death, reactive oxygen species (ROS) production, inflammatory activation, blood–brain barrier (BBB) disruption, and brain edema underlying ICH. We emphasize the potential of mitochondrial protection as a potential therapeutic target for SBI after stroke and provide valuable insight into clinical strategies.

Neuroinflammation and Precision Medicine in Pediatric Neurocritical Care: Multi-Modal Monitoring of Immunometabolic Dysfunction

The understanding of molecular biology in neurocritical care (NCC) is expanding rapidly and recognizing the important contribution of neuroinflammation, specifically changes in immunometabolism, towards pathological disease processes encountered across all illnesses in the NCC. Additionally, the importance of individualized inflammatory responses has been emphasized, acknowledging that not all individuals have the same mechanisms contributing towards their presentation. By understanding cellular processes that drive disease, we can make better personalized therapy decisions to improve patient outcomes. While the understanding of these cellular processes is evolving, the ability to measure such cellular responses at bedside to make acute care decisions is lacking. In this overview, we review cellular mechanisms involved in pathological neuroinflammation with a focus on immunometabolic dysfunction and review non-invasive bedside tools that have the potential to measure indirect and direct markers of shifts in cellular metabolism related to neuroinflammation. These tools include near-infrared spectroscopy, transcranial doppler, elastography, electroencephalography, magnetic resonance imaging and spectroscopy, and cytokine analysis. Additionally, we review the importance of genetic testing in providing information about unique metabolic profiles to guide individualized interpretation of bedside data. Together in tandem, these modalities have the potential to provide real time information and guide more informed treatment decisions.

Ferroptosis, a Regulated Neuronal Cell Death Type After Intracerebral Hemorrhage

Ferroptosis is a term that describes one form of regulated non-apoptotic cell death. It is triggered by the iron-dependent accumulation of lipid peroxides. Emerging evidence suggests a link between ferroptosis and the pathophysiological processes of neurological disorders, including stroke, degenerative diseases, neurotrauma, and cancer. Hemorrhagic stroke, also known as intracerebral hemorrhage (ICH), belongs to a devastating illness for its high level in morbidity and mortality. Currently, there are few established treatments and limited knowledge about the mechanisms of post-ICH neuronal death. The secondary brain damage after ICH is mainly attributed to oxidative stress and hemoglobin lysate, including iron, which leads to irreversible damage to neurons. Therefore, ferroptosis is becoming a common trend in research of neuronal death after ICH. Accumulative data suggest that the inhibition of ferroptosis may effectively prevent neuronal ferroptosis, thereby reducing secondary brain damage after ICH in animal models. Ferroptosis has a close relationship with oxidative damage and iron metabolism. This review reveals the pathological pathways and regulation mechanism of ferroptosis following ICH and then offers potential intervention strategies to mitigate neuron death and dysfunction after ICH.

Antioxidant and hepatorenal protective effects of bee pollen fractions against propionic acid-induced autistic feature in rats

In the brain, propionic acid (PA) can cross cell membranes and accumulate within cells, leading to intracellular acidification, which may alter neurotransmitter release (NT), communication between neurons, and behavior. Such elevation in levels of PA constitutes a neurodevelopmental metabolic disorder called propionic acidemia, which could clinically manifest as autism. The purpose of this study was to investigate the protective effects of different fractions of bee pollen (BP) on PA-induced autism in rats, and to evaluate their effects on the expression of liver and renal biomarkers. Groups of rats received treatments of different fractions of BP at a dose of 250 mg/kg of body weight/day for a period of 1 month. Normal control group I and group II were orally administered with phosphate-buffered saline and propionic acid, respectively, for 3 days. BP contains various health-promoting phenolic components. Different fractions of BP administered pre- and post-treatment with PA showed significant reduction in the levels of liver and renal biomarkers (p < .05). Also, a significant enhancement in the levels of glutathione S-transferase (GST), catalase CAT), and ascorbic acid (VIT C) was observed. Supplementation with BP significantly reduced biochemical changes in the liver, kidneys, and brain of rats with PA-induced toxicity. It exhibited protective effects against oxidative damage and reactive oxygen species produced by PA-induced adverse reactions in rats. Taken together, our study shows that BP possesses protective effects in PA-induced liver and kidney damage.

The effect of melatonin on reduction in the need for sedative agents and duration of mechanical ventilation in traumatic intracranial hemorrhage patients: a randomized controlled trial

Purpose

This study aimed to determine the effect of exogenous melatonin on the number of sedative drugs and the duration of mechanical ventilation in traumatic intracranial hemorrhage patients in ICU.

Methods

This double-blind randomized clinical trial study was conducted in the ICU wards of Golestan Hospital, Ahvaz, Iran, from September 2017 to March 2018. In this study, 52 patients with intracerebral hemorrhage were selected by convenient sampling (26 patients in each group) and were randomly assigned to two groups of melatonin and control. Sedation and pain management package was applied to both groups. Outcomes: Amount of the sedative and opioid drug; mechanical ventilation time; ICU staying time; Glasgow Coma Score; hemodynamic parameters.

Results

There was no significant difference between them in terms of demographic characteristics. Cumulative doses of morphine and mechanical ventilation time were significant in two groups. (P < 0.05) The mean length of ICU staying was not significant. Glasgow Coma Score on the 6th day was significant in two groups (P < 0.05). Diastolic blood pressure was significant between groups (P < 0.001).

Conclusion

This study presented that morphine consumption and mechanical ventilation time were significantly lower in the melatonin group than in the control. Also, rise in GCS in the melatonin group was faster in the melatonin group than in the control. The use of melatonin can be recommended for patients with ICH in the ICU for better outcomes.

Activation of Nrf2 by Natural Bioactive Compounds: A Promising Approach for Stroke?

Stroke represents one of the main causes of disability and death worldwide. The pathological subtypes of stroke are ischemic stroke, the most frequent, and hemorrhagic stroke. Nrf2 is a transcription factor that regulates redox homeostasis. In stress conditions, Nrf2 translocates inside the nucleus and induces the transcription of enzymes involved in counteracting oxidative stress, endobiotic and xenobiotic metabolism, regulators of inflammation, and others. Different natural compounds, including food and plant-derived components, were shown to be able to activate Nrf2, mediating an antioxidant response. Some of these compounds were tested in stroke experimental models showing several beneficial actions. In this review, we focused on the studies that evidenced the positive effects of natural bioactive compounds in stroke experimental models through the activation of Nrf2 pathway. Interestingly, different natural compounds can activate Nrf2 through multiple pathways, inducing a strong antioxidant response associated with the beneficial effects against stroke. According to several studies, the combination of different bioactive compounds can lead to a better neuroprotection. In conclusion, natural bioactive compounds may represent new therapeutic strategies against stroke.