A small-molecule-inducible Nrf2-mediated antioxidant response provides effective prophylaxis against cerebral ischemia in vivo

Iron homeostasis and ferroptosis in human diseases: mechanisms and therapeutic prospects

Iron, an essential mineral in the body, is involved in numerous physiological processes, making the maintenance of iron homeostasis crucial for overall health. Both iron overload and deficiency can cause various disorders and human diseases. Ferroptosis, a form of cell death dependent on iron, is characterized by the extensive peroxidation of lipids. Unlike other kinds of classical unprogrammed cell death, ferroptosis is primarily linked to disruptions in iron metabolism, lipid peroxidation, and antioxidant system imbalance. Ferroptosis is regulated through transcription, translation, and post-translational modifications, which affect cellular sensitivity to ferroptosis. Over the past decade or so, numerous diseases have been linked to ferroptosis as part of their etiology, including cancers, metabolic disorders, autoimmune diseases, central nervous system diseases, cardiovascular diseases, and musculoskeletal diseases. Ferroptosis-related proteins have become attractive targets for many major human diseases that are currently incurable, and some ferroptosis regulators have shown therapeutic effects in clinical trials although further validation of their clinical potential is needed. Therefore, in-depth analysis of ferroptosis and its potential molecular mechanisms in human diseases may offer additional strategies for clinical prevention and treatment. In this review, we discuss the physiological significance of iron homeostasis in the body, the potential contribution of ferroptosis to the etiology and development of human diseases, along with the evidence supporting targeting ferroptosis as a therapeutic approach. Importantly, we evaluate recent potential therapeutic targets and promising interventions, providing guidance for future targeted treatment therapies against human diseases.

Metformin ameliorates neuroinflammatory environment for neurons and astrocytes during in vitro and in vivo stroke and tobacco smoke chemical exposure: Role of Nrf2 activation

Despite the protective nature of the blood-brain barrier (BBB) and brain-protecting tissues, some types of CNS injury or stress can cause cerebral cytokine production and profound alterations in brain function. Neuroinflammation, which can also be accompanied by increased cerebral cytokine production, has a remarkable impact on the pathogenesis of many neurological illnesses, including loss of BBB integrity and ischemic stroke, yet effective treatment choices for these diseases are currently lacking. Although little is known about the brain effects of Metformin (MF), a commonly prescribed first-line antidiabetic drug, prior research suggested that it may be useful in preventing BBB deterioration and the increased risk of stroke caused by tobacco smoking (TS). Therefore, reducing neuroinflammation by escalating anti-inflammatory cytokine production and declining pro-inflammatory cytokine production could prove an effective therapeutic strategy for ischemic stroke. Hence, the current investigation was planned to explore the potential role of MF against stroke and TS-induced neuroinflammation and reactive oxygen species (ROS) production. Our studies revealed that MF suppressed releasing pro-inflammatory mediators like tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) by aiming at the nuclear factor kappa B (NF-κB) signaling pathway in primary neurons and astrocytes. MF also upregulated anti-inflammatory mediators, like interleukin-10 (IL-10), and interleukin-4 (IL-4), by upregulating the Nrf2-ARE signaling pathway. Adolescent mice receiving MF along with TS exposure also showed a notable decrease in NF-κB expression compared to the mice not treated with MF and significantly decreased the level of TNF-α, IL-1β, MCP-1, and MIP-2 and increased the levels of IL-10 and IL-4 through the activation of Nrf2-ARE signaling pathway. These results suggest that MF has anti-neuroinflammatory effects via inhibiting NF-κB signaling by activating Nrf2-ARE. These studies support that MF could be a strong candidate drug for treating and or preventing TS-induced neuroinflammation and ischemic stroke.

Exploring Research Trend and Hotspots on Oxidative Stress in Ischemic Stroke (2001-2022): Insights from Bibliometric

Oxidative stress is widely involved in the pathological process of ischemic stroke and ischemia-reperfusion. Several research have demonstrated that eliminating or reducing oxidative stress can alleviate the pathological changes of ischemic stroke. However, current clinical antioxidant treatment did not always perform as expected. This bibliometric research aims to identify research trends, topics, hotspots, and evolution on oxidative stress in the field of ischemic stroke, and to find potentially antioxidant strategies in future clinical treatment. Relevant publications were searched from the Web of Science (WOS) Core Collection databases (2001-2022). VOSviewer was used to visualize and analyze the development trends and hotspots. In the field of oxidative stress and ischemic stroke, the number of publications increased significantly from 2001 to 2022. China and the USA were the leading countries for publication output. The most prolific institutions were Stanford University. Journal of Cerebral Blood Flow and Metabolism and Stroke were the most cited journals. The research topics in this field include inflammation with oxidative stress, mitochondrial damage with oxidative stress, oxidative stress in reperfusion injury, oxidative stress in cognitive impairment and basic research and clinical translation of oxidative stress. Moreover, "NLRP3 inflammasome," "autophagy," "mitophagy," "miRNA," "ferroptosis," and "signaling pathway" are the emerging research hotspots in recent years. At present, multi-target regulation focusing on multi-mechanism crosstalk has progressed across this period, while challenges come from the transformation of basic research to clinical application. New detection technology and new nanomaterials are expected to integrate oxidative stress into the clinical treatment of ischemic stroke better.

LRRK2 kinase activity restricts NRF2-dependent mitochondrial protection in microglia

Mounting evidence supports a critical role for central nervous system (CNS) glial cells in neuroinflammation and neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's Disease (PD), Multiple Sclerosis (MS), as well as neurovascular ischemic stroke. Previously, we found that loss of the PD-associated gene leucine-rich repeat kinase 2 (Lrrk2) in macrophages, peripheral innate immune cells, induced mitochondrial stress and elevated basal expression of type I interferon (IFN) stimulated genes (ISGs) due to chronic mitochondrial DNA engagement with the cGAS/STING DNA sensing pathway. Here, we report that loss of LRRK2 results in a paradoxical response in microglial cells, a CNS-specific macrophage population. In primary murine microglia and microglial cell lines, loss of Lrrk2 reduces tonic IFN signaling leading to a reduction in ISG expression. Consistent with reduced type I IFN, mitochondria from Lrrk2 KO microglia are protected from stress and have elevated metabolism. These protective phenotypes involve upregulation of NRF2, an important transcription factor in the response to oxidative stress and are restricted by LRRK2 kinase activity. Collectively, these findings illustrate a dichotomous role for LRRK2 within different immune cell populations and give insight into the fundamental differences between immune regulation in the CNS and the periphery.

Interaction between RNF4 and SART3 is associated with the risk of schizophrenia

The pathogenesis of schizophrenia (SCZ) is heavily influenced by genetic factors. Ring finger protein 4 (RNF4) and squamous cell carcinoma antigen recognized by T cells 3 (SART3) are thought to be involved in nervous system growth and development via oxidative stress pathways. Moreover, they have previously been linked to SCZ. Yet the role of RNF4 and SART3 in SCZ remains unclear. Here, we investigated how these two genes are involved in SCZ by studying their variants observed in patients. We first observed significantly elevated mRNA levels of RNF4 and SART3 in the peripheral blood in both first-episode (n = 30) and chronic (n = 30) SCZ patients compared to controls (n = 60). Next, we targeted-sequenced three single nucleotide polymorphisms (SNPs) in SART3 and six SNPs in RNF4 for association with SCZ using the genomic DNA extracted from peripheral blood leukocytes from SCZ participants (n = 392) and controls (n = 572). We observed a combination of SNPs that included rs1203860, rs2282765 (both in RNF4), and rs2287550 (in SART3) was associated with increased risk of SCZ, suggesting common pathogenic mechanisms between these two genes. We then conducted experiments in HEK293T cells to better understand the interaction between RNF4 and SART3. We observed that SART3 lowered the expression of RNF4 through ubiquitination and downregulated the expression of nuclear factor E2-related factor 2 (NRF2), a downstream factor of RNF4, implicating the existence of a possible shared regulatory mechanism for RNF4 and SART3. In conclusion, our study provides evidence that the interaction between RNF4 and SART3 contributes to the risk of SCZ. The findings shed light on the underlying molecular mechanisms of SCZ and may lead to the development of new therapies and interventions for this disorder.

Dose-dependent renoprotective effect of vanillic acid on methotrexate-induced nephrotoxicity via its anti-apoptosis, antioxidant, and anti-inflammatory properties

Methotrexate-induced nephrotoxicity is a medical emergency which is associated with a variety of side effects. Vanillic acid (VA), as an antioxidant, removes free radical oxygen to protect cell defense. Therefore, this study investigated VA's beneficial effects on nephrotoxicity induced by methotrexate through its anti-apoptosis, antioxidant, and anti-inflammatory properties. Our study included five groups of male Wistar rats (n = 8): sham, MTX (Methotrexate) group: rats receiving methotrexate (20 mg/kg, intraperitoneally) on Day 2. Moreover, the remaining groups consisted of animals that received vanillic acid (25, 50, and 100 mg/kg, orally for seven days) plus MTX on the 2nd day. The rats were deeply anesthetized on the eighth day to obtain blood and renal tissue samples. The results showed that MTX can increase blood urea nitrogen and creatinine. However, VA (50 and 100 mg/kg) improved renal function as approved by histological findings. Compared with MTX-treated rats, VA enhanced the contents of total antioxidant capacity (TAC) and reduced renal malondialdehyde (MDA). Moreover, VA reduced mRNA expressions of caspase-3 and Bcl-2-associated x protein (Bax) and caused mRNA overexpression of the renal B-cell lymphoma-2 (Bcl-2), and Nrf-2 (Nuclear factor erythroid 2-related factor 2) compared to the MTX group. Also, VA administration significantly reduced inflammatory agents. Overall, VA protects the kidneys against methotrexate-induced nephrotoxicity via anti-apoptosis, antioxidant, and anti-inflammatory properties. Our results revealed that the most effective dose of VA was 100 mg/kg.

Beneficial effect of lupeol and metformin in mouse model of intracerebroventricular streptozotocin induced dementia

This study examines the effectiveness of lupeol and metformin in a mouse model of dementia generated by intracerebroventricular streptozotocin (i.c.v., STZ). Dementia was induced in Swiss mice with the i.c.v. administration of STZ at a dosage of 3 mg/kg on the first and third day. The assessment of dementia involved an examination of the Morris Water Maze (MWM) performance, as well as a number of biochemical and histological studies. STZ treatment resulted in significant decrease in MWM performance; various biochemical alterations (increase in brain acetyl cholinesterase (AChE) activity, thiobarbituric acid reactive species (TBARS), nitrite/nitrate, and reduction in nuclear factor erythroid 2 related factor-2 (Nrf-2), reduced glutathione (GSH) levels) and neuroinflammation [increased myeloperoxidase (MPO) activity & neutrophil infiltration]. The administration of Lupeol (50 mg/kg & 100 mg/kg; p.o.) and Metformin (150 mg/kg & 300 mg/kg; p.o.) demonstrated a considerable reduction in the behavioral, biochemical, and histological alterations produced by STZ. Low dose combination of lupeol (50 mg/kg; p.o.) and Metformin (150 mg/kg; p.o.) produced more pronounced effect than that of high doses of either agent alone. It is concluded that Lupeol and Metformin has shown efficacy in dementia with possible synergism between the two and can be explored as potential therapeutic agents for managing dementia of Alzheimer's disease (AD) type.

The cell-specific roles of Nrf2 in acute and chronic phases of ischemic stroke

Ischemic stroke refers to the sudden loss of blood flow in a specific area of the brain. It is the fifth leading cause of mortality and the leading cause of permanent disability. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) controls the production of several antioxidants and protective proteins and it has been investigated as a possible pharmaceutical target for reducing harmful oxidative events in brain ischemia. Each cell type exhibits different roles and behaviors in different phases post-stroke, which is comprehensive yet important to understand to optimize management strategies and goals for care for stroke patients. In this review, we comprehensively summarize the protective effects of Nrf2 in experimental ischemic stroke, emphasizing the role of Nrf2 in different cell types including neurons, astrocytes, oligodendrocytes, microglia, and endothelial cells during acute and chronic phases of stroke and providing insights on the neuroprotective role of Nrf2 on each cell type throughout the long term of stroke care. We also highlight the importance of targeting Nrf2 in clinical settings while considering a variety of important factors such as age, drug dosage, delivery route, and time of administration.

Caffeic acid alleviates cerebral ischemic injury in rats by resisting ferroptosis via Nrf2 signaling pathway

There are few effective and safe neuroprotective agents for the treatment of ischemic stroke currently. Caffeic acid is a phenolic acid that widely exists in a number of plant species. Previous studies show that caffeic acid ameliorates brain injury in rats after cerebral ischemia/reperfusion. In this study we explored the protective mechanisms of caffeic acid against oxidative stress and ferroptosis in permanent cerebral ischemia. Ischemia stroke was induced on rats by permanent middle cerebral artery occlusion (pMCAO). Caffeic acid (0.4, 2, 10 mg·kg-1·d-1, i.g.) was administered to the rats for 3 consecutive days before or after the surgery. We showed that either pre-pMCAO or post-pMCAO administration of caffeic acid (2 mg·kg-1·d-1) effectively reduced the infarct volume and improved neurological outcome. The therapeutic time window could last to 2 h after pMCAO. We found that caffeic acid administration significantly reduced oxidative damage as well as neuroinflammation, and enhanced antioxidant capacity in pMCAO rat brain. We further demonstrated that caffeic acid down-regulated TFR1 and ACSL4, and up-regulated glutathione production through Nrf2 signaling pathway to resist ferroptosis in pMCAO rat brain and in oxygen glucose deprivation/reoxygenation (OGD/R)-treated SK-N-SH cells in vitro. Application of ML385, an Nrf2 inhibitor, blocked the neuroprotective effects of caffeic acid in both in vivo and in vitro models, evidenced by excessive accumulation of iron ions and inactivation of the ferroptosis defense system. In conclusion, caffeic acid inhibits oxidative stress-mediated neuronal death in pMCAO rat brain by regulating ferroptosis via Nrf2 signaling pathway. Caffeic acid might serve as a potential treatment to relieve brain injury after cerebral ischemia. Caffeic acid significantly attenuated cerebral ischemic injury and resisted ferroptosis both in vivo and in vitro. The regulation of Nrf2 by caffeic acid initiated the transcription of downstream target genes, which were shown to be anti-inflammatory, antioxidative and antiferroptotic. The effects of caffeic acid on neuroinflammation and ferroptosis in cerebral ischemia were explored in a primary microglia-neuron coculture system. Caffeic acid played a role in reducing neuroinflammation and resisting ferroptosis through the Nrf2 signaling pathway, which further suggested that caffeic acid might be a potential therapeutic method for alleviating brain injury after cerebral ischemia.

Gulf War toxicant-induced reductions in dendritic arbors and spine densities of dentate granule cells are improved by treatment with a Nrf2 activator

Gulf War Illness (GWI) is a chronic multi-symptom disorder affecting approximately 30 % of Veterans deployed to the Persian Gulf from 1990 to 91. GWI encompasses a wide spectrum of symptoms which frequently include neurological problems such as learning and memory impairments, mood disorders, and an increased incidence of neurodegenerative disorders. Combined exposure to both reversible and irreversible acetylcholinesterase (AChE) inhibitors has been identified as a likely risk factor for GWI. It is possible that the exposures affected connectivity in the brain, and it was also unknown whether this could benefit from treatment. We assessed chronic changes in dendritic architecture in granule cells of the dentate gyrus following exposure to pyridostigmine bromide (PB, 0.7 mg/kg), chlorpyrifos (CPF, 12.5 mg/kg), and N,N-diethyl-m-toluamide (DEET, 7.5 mg/kg) in male C57Bl/6J mice. We also evaluated the therapeutic effects of dietary administration for eight weeks of 1 % tert-butylhydroquinone (tBHQ), a Nrf2 activator, on long-term neuronal morphology. We found that Gulf War toxicant exposure resulted in reduced dendritic length and branching as well as overall spine density in dentate granule cells at 14 weeks post-exposure and that these effects were ameliorated by treatment with tBHQ. These findings indicate that Gulf War toxicant exposure results in chronic changes to dentate granule cell morphology and that modulation of neuroprotective transcription factors such as Nrf2 may improve long-term neuronal health in the hippocampus.

Neuroprotection during Thrombectomy for Acute Ischemic Stroke: A Review of Future Therapies

Stroke is a major cause of death and disability worldwide. Endovascular thrombectomy has been impactful in decreasing mortality. However, many clinical results continue to show suboptimal functional outcomes despite high recanalization rates. This gap in recanalization and symptomatic improvement suggests a need for adjunctive therapies in post-thrombectomy care. With greater insight into ischemia-reperfusion injury, recent preclinical testing of neuroprotective agents has shifted towards preventing oxidative stress through upregulation of antioxidants and downstream effectors, with positive results. Advances in multiple neuroprotective therapies, including uric acid, activated protein C, nerinetide, otaplimastat, imatinib, verapamil, butylphthalide, edaravone, nelonemdaz, ApTOLL, regional hypothermia, remote ischemic conditioning, normobaric oxygen, and especially nuclear factor erythroid 2-related factor 2, have promising evidence for improving stroke care. Sedation and blood pressure management in endovascular thrombectomy also play crucial roles in improved stroke outcomes. A hand-in-hand approach with both endovascular therapy and neuroprotection may be the key to targeting disability due to stroke.

Food Polyphenols as Preventive Medicine

Reactive oxygen species (ROS) are the initiators in foods and in the stomach of oxidized dietary lipids, proteins, and lipid-oxidation end-products (ALEs), inducing in humans the development of several chronic diseases and cancer. Epidemiological, human clinical and animal studies supported the role of dietary polyphenols and derivatives in prevention of development of such chronic diseases. There is much evidence that polyphenols/derivatives at the right timing and concentration, which is critical, acts mostly in the aerobic stomach and generally in the gastrointestinal tract as reducing agents, scavengers of free radicals, trappers of reactive carbonyls, modulators of enzyme activity, generators of beneficial gut microbiota and effectors of cellular signaling. In the blood system, at low concentration, they act as generators of electrophiles and low concentration of H2O2, acting mostly as cellular signaling, activating the PI3K/Akt-mediated Nrf2/eNOS pathways and inhibiting the inflammatory transcription factor NF-κB, inducing the cells, organs and organism for eustress, adaptation and surviving.

Emerging trends and hotspots of Nuclear factor erythroid 2-related factor 2 in nervous system diseases

BACKGROUND

The Nuclear factor erythroid 2-related factor 2 (NRF2) transcription factor has attracted much attention in the context of neurological diseases. However, none of the studies have systematically clarified this field's research hotspots and evolution rules.

AIM

To investigate the research hotspots, evolution patterns, and future research trends in this field in recent years.

METHODS

We conducted a comprehensive literature search in the Web of Science Core Collection database using the following methods: (((((TS=(NFE2 L2)) OR TS=(Nfe2 L2 protein, mouse)) OR TS=(NF-E2-Related Factor 2)) OR TS=(NRF2)) OR TS=(NFE2L2)) OR TS=(Nuclear factor erythroid2-related factor 2) AND (((((((TS=(neurological diseases)) OR TS=(neurological disorder)) OR TS=(brain disorder)) OR TS=(brain injury)) OR TS=(central nervous system disease)) OR TS=(CNS disease)) OR TS=(central nervous system disorder)) OR TS=(CNS disorder) AND Language = English from 2010 to 2022. There are just two forms of literature available: Articles and reviews. Data were processed with the software Cite-Space (version 6.1. R6).

RESULTS

We analyzed 1884 articles from 200 schools in 72 countries/regions. Since 2015, the number of publications in this field has increased rapidly. China has the largest number of publications, but the articles published in the United States have better centrality and H-index. Among the top ten authors with the most published papers, five of them are from China, and the author with the most published papers is Wang Handong. The institution with the most articles was Nanjing University. To their credit, three of the top 10 most cited articles were written by Chinese scholars. The keyword co-occurrence map showed that "oxidative stress", "NRF2", "activation", "expression" and "brain" were the five most frequently used keywords.

CONCLUSION

Research on the role of NRF2 in neurological diseases continues unabated. Researchers in developed countries published more influential papers, while Chinese scholars provided the largest number of articles. There have been numerous studies on the mechanism of NRF2 transcription factor in neurological diseases. NRF2 is also emerging as a potentially effective target for the treatment of neurological diseases. However, despite decades of research, our knowledge of NRF2 transcription factor in nervous system diseases is still limited. Further studies are needed in the future.

Nrf2 and Ferroptosis: A New Research Direction for Ischemic Stroke

Ischemic stroke (IS) is one of the leading causes of death and morbidity worldwide. As a novel form of cell death, ferroptosis is an important mechanism of ischemic stroke. Nuclear factor E2-related factor 2 (Nrf2) is the primary regulator of cellular antioxidant response. In addition to alleviating ischemic stroke nerve damage by reducing oxidative stress, Nrf2 regulates genes associated with ferroptosis, suggesting that Nrf2 may inhibit ferroptosis after ischemic stroke. However, the specific pathway of Nrf2 on ferroptosis in the field of ischemic stroke remains unclear. Therefore, this paper provides a concise overview of the mechanisms underlying ferroptosis, with a particular focus on the regulatory role of Nrf2. The discussion highlights the potential connections between Nrf2 and the mitigation of oxidative stress, regulation of iron metabolism, modulation of the interplay between ferroptosis and inflammation, as well as apoptosis. This paper focuses on the specific pathway of Nrf2 regulation of ferroptosis after ischemic stroke, providing scientific research ideas for further research on the treatment of ischemic stroke.

1,8-Cineole Alleviates OGD/R-Induced Oxidative Damage and Restores Mitochondrial Function by Promoting the Nrf2 Pathway

This study examined the effects of 1,8-cineole on reducing oxidative stress injury and restoring mitochondrial function in oxygen-glucose deprivation and reoxygenation (OGD/R) HT22 cells via the nuclear factor erythrocyte 2 related factor 2 (Nrf2) pathway. The optimal concentration of 1,8-cineole to reduce OGD/R injury was screened via cell morphology, cell survival rate, and lactate dehydrogenase (LDH) leakage rate. Oxidative damage was observed by measuring superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), catalase (CAT) activities, and reactive oxygen species (ROS), glutathione (GSH), protein carbonyl, malondialdehyde (MDA), lipid peroxidation (LPO) content, and 8-hydroxy-2 deoxyguanosine (8-OHDG) expression. Mitochondrial function was observed by mitochondrial membrane potential (MMP) and ATPase activity. Nrf2 pathways were observed by the expression levels of total Nrf2, nucleus Nrf2, reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H): quinone oxidoreductase 1 (NQO1) and heme oxygenase-1 (HO-1), the mRNA levels of HO-1 and NQO1. Among different concentrations of 1,8-cineole for promoting HT22 cell proliferation and attenuated OGD/R injury, 10 µmol/L 1,8-cineole was the best. After 1,8-cineole treatment, SOD, GSH-PX, and CAT activities and GSH content increased, while ROS, MDA, LPO, protein carbonyl, and 8-OHDG levels decreased. 1,8-Cineole could restore MMP and increase mitochondrial enzyme activity. It could also increase the total Nrf2, nucleus Nrf2, NQO1, and HO-1, and Nrf2 inhibitor brusatol reduced the effect of 1,8-cineole. Immunofluorescence assay showed that 1,8-cineole could facilitate the transfer of Nrf2 into the nucleus. 1,8-cineole increased the mRNA levels of NQO1 and HO-1. The above results showed that 1,8-cineole could alleviate OGD/R-induced oxidative damage and restores mitochondrial function by activating the Nrf2 signal pathway.

Neuroprotective Effects of Phenolic Antioxidant Tert-butylhydroquinone (tBHQ) in Brain Diseases

Human life and health are gravely threatened by brain diseases. The onset and progression of the illnesses are influenced by a variety of factors, including pathogenic causes, environmental factors, mental issues, etc. According to scientific studies, neuroinflammation and oxidative stress play a significant role in the development and incidence of brain diseases by producing pro-inflammatory cytokines and oxidative tissue damage to induce inflammation and apoptosis. Neuroinflammation, oxidative stress, and oxidative stress-related changes are inseparable factors in the etiology of several brain diseases. Numerous neurodegenerative diseases have undergone substantial research into the therapeutic alternatives that target oxidative stress, the function of oxidative stress, and the possible therapeutic use of antioxidants. Formerly, tBHQ is a synthetic phenolic antioxidant, which has been widely used as a food additive. According to recent researches, tBHQ can suppress the processes that lead to neuroinflammation and oxidative stress, which offers a fresh approach to treating brain diseases. In order to achieve the goal of decreasing inflammation and apoptosis, tBHQ is a specialized nuclear factor erythroid 2-related factor (Nrf2) activator that decreases oxidative stress and enhances antioxidant status by upregulating the Nrf2 gene and reducing nuclear factor kappa-B (NF-κB) activity. This article reviews the effects of tBHQ on neuroinflammation and oxidative stress in recent years and looks into how tBHQ inhibits neuroinflammation and oxidative stress through human, animal, and cell experiments to play a neuroprotective role in Alzheimer's disease (AD), stroke, depression, and Parkinson's disease (PD). It is anticipated that this article will be useful as a reference for upcoming research and the creation of drugs to treat brain diseases.

Sirtuins: Promising Therapeutic Targets to Treat Ischemic Stroke

Stroke is a major cause of mortality and disability globally, with ischemic stroke (IS) accounting for over 80% of all stroke cases. The pathological process of IS involves numerous signal molecules, among which are the highly conserved nicotinamide adenine dinucleotide (NAD+)-dependent enzymes known as sirtuins (SIRTs). SIRTs modulate various biological processes, including cell differentiation, energy metabolism, DNA repair, inflammation, and oxidative stress. Importantly, several studies have reported a correlation between SIRTs and IS. This review introduces the general aspects of SIRTs, including their distribution, subcellular location, enzyme activity, and substrate. We also discuss their regulatory roles and potential mechanisms in IS. Finally, we describe the current therapeutic methods based on SIRTs, such as pharmacotherapy, non-pharmacological therapeutic/rehabilitative interventions, epigenetic regulators, potential molecules, and stem cell-derived exosome therapy. The data collected in this study will potentially contribute to both clinical and fundamental research on SIRTs, geared towards developing effective therapeutic candidates for future treatment of IS.

Prolactin-induced neuroprotection against excitotoxicity is mediated via PI3K/AKT and GSK3β/NF-κB in primary cultures of hippocampal neurons

Prolactin (PRL) is a polypeptide hormone that has been reported to play a significant role in neuroprotection against neuronal excitotoxicity produced by glutamate (Glu) or kainic acid (KA) in both, in vitro and in vivo models. However, the molecular mechanisms involved in PRL's neuroprotective effects in the hippocampus have not been completely elucidated. The aim of the present study was to assess the signaling pathways involved in PRL neuroprotection against excitotoxicity. Primary rat hippocampal neuronal cell cultures were used to assess PRL-induced signaling pathway activation. The effects of PRL on neuronal viability, as well as its effects on activation of key regulatory pathways, phosphoinositide 3-kinases/Protein Kinase B (PI3K/AKT) and glycogen synthase kinase 3β / nuclear factor kappa B (GSK3β/NF-κB), were evaluated under conditions of Glutamate-induced excitotoxicity. Additionally, the effect on downstream regulated genes such as Bcl-2 and Nrf2, was assessed. Here, we show that the PI3K/AKT signaling pathway is activated by PRL treatment during excitotoxicity, promoting neuronal survival through upregulation of active AKT and GSK3β/NF-κB, resulting in induction of Bcl-2 and Nrf2 gene expression. Inhibition of the PI3K/AKT signaling pathway abrogated the protective effect of PRL against Glu-induced neuronal death. Overall, results indicate that the neuroprotective actions of PRL are mediated in part, by the activation of the AKT pathway and survival genes. Our data support the idea that PRL could be useful as a potential neuroprotective agent in different neurological and neurodegenerative diseases.

A comprehensive review of stroke-related signaling pathways and treatment in western medicine and traditional Chinese medicine

This review provides insight into the complex network of signaling pathways and mechanisms involved in stroke pathophysiology. It summarizes the historical progress of stroke-related signaling pathways, identifying potential interactions between them and emphasizing that stroke is a complex network disease. Of particular interest are the Hippo signaling pathway and ferroptosis signaling pathway, which remain understudied areas of research, and are therefore a focus of the review. The involvement of multiple signaling pathways, including Sonic Hedgehog (SHH), nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE), hypoxia-inducible factor-1α (HIF-1α), PI3K/AKT, JAK/STAT, and AMPK in pathophysiological mechanisms such as oxidative stress and apoptosis, highlights the complexity of stroke. The review also delves into the details of traditional Chinese medicine (TCM) therapies such as Rehmanniae and Astragalus, providing an analysis of the recent status of western medicine in the treatment of stroke and the advantages and disadvantages of TCM and western medicine in stroke treatment. The review proposes that since stroke is a network disease, TCM has the potential and advantages of a multi-target and multi-pathway mechanism of action in the treatment of stroke. Therefore, it is suggested that future research should explore more treasures of TCM and develop new therapies from the perspective of stroke as a network disease.

Buyang Huanwu decoction alleviates oxidative injury of cerebral ischemia-reperfusion through PKCε/Nrf2 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ischemic stroke is a significant risk factor for human health, and Buyang Huanwu Decoction is a classical and famous Chinese formula for treating it, but without clear pharmacological mechanism.

AIM OF THE STUDY

The aim of this study was to investigate that the molecular mechanism of BYHWD activation of the PKCε/Nrf2 signaling pathway to attenuate cerebral ischemia-reperfusion (I/R) oxidative damage.

MATERIALS AND METHODS

The MCAO method was used to establish a brain I/R injury model in SD rats, and neurological deficits were evaluated by neurological function score. Neuronal damage was observed by Nissl staining and immunofluorescence detection of MAP2 expression. Oxidative damage was observed by ROS, SOD, GSH-PX, MDA, and 8-OHdG. Changes in mitochondrial membrane potential were detected by using the fluorescent probe JC-1. The Western blot analysis detected protein expression of PKCε, P-PKCε, total Nrf2, nuclear Nrf2, HO-1, and NQO1.

RESULTS

BYHWD significantly enhanced neural function, reduced neuronal damage, inhibited the production of ROS, decreased MDA and 8-OHdG levels, increased SOD and GSH-PX activity to reduce oxidative damage, and restored mitochondrial membrane potential. BYHWD and Nrf2 activator TBHQ increased total Nrf2, nucleus Nrf2 protein expression, and its downstream HO-1 and NQO1 proteins, and the administration of the Nrf2 inhibitor brusatol reduced the enhancing effect of BYHWD. Meanwhile, BYHWD increased the expression of PKCε and P-PKCε and the administration of the PKCε inhibitor εV1-2 reduced the effect of BYHWD in increasing the expression of PKCε, P-PKCε, nuclear Nrf2, and HO-1, as well as promoting the effect of Nrf2 translocation to the nucleus.

CONCLUSION

This study marks the first to demonstrate that BYHWD ameliorates oxidative damage and attenuates brain I/R injury by activating the PKCε/Nrf2/HO-1 pathway.

Nrf2 is expressed more extensively in neurons than in astrocytes following an acute epileptic seizure in rats

The modulation of the nuclear factor erythroid 2-like 2 (Nrf2) activity has been reported to be implicated in the pathology of various neurological disorders, including epilepsy. Previous studies have demonstrated that Nrf2 is activated in the post-status epilepticus rat model; however, the spatiotemporal as well as cell type-specific expression of Nrf2 following brief epileptic seizures remains unclear. Here, we evaluated how an acute epileptic seizure affected the expression of Nrf2 and its downstream genes in the rats' cortex and the hippocampus up to 1 week following the induced seizure. We found that after a pentylenetetrazol-induced seizure, Nrf2 significantly increased at 24 h at the mRNA level and 3 h at the protein level in the cortex. In the hippocampus, the Nrf2 mRNA level peaked at 3 h after the seizure, and no significant changes were observed in the protein level. Interestingly, the mRNA level of Nrf2 downstream genes peaked at 3-6 h after seizure in both the cortex and the hippocampus. A significant increase in the expression of Nrf2 was observed in the neuronal population of CA1 and CA3 regions of the hippocampus, as well as in the cortex. Moreover, we observed no change in the co-localization of Nrf2 with astrocytes neither in the cortex nor in CA1 and CA3. Our results revealed that following a brief acute epileptic seizure, the expression of Nrf2 and its downstream genes is transiently increased and peaked at early timepoints after the seizure predominantly in the hippocampus, and this expression is restricted to the neuronal population.

The Effect and Mechanism of Syringa pinnatifolia Hemsl. Ligans on Cerebral Ischemia-Reperfusion Injury and Oxidative Stress in Mice

Lignans are the main components of Syringa pinnatifolia Hemsl. (SP). Previous studies have shown that SP lignans (SPL) can considerably improve CCl₄-induced acute liver injury in mice by the anti-oxidative stress (OS) mechanism. In this study, we investigated the antioxidant effects of SPL on cerebral ischemia/reperfusion injury (CIRI) and its underlying molecular mechanism. We developed a middle cerebral artery occlusion/reperfusion (MCAO/R) model in mice to achieve CIRI and orally administered SPL daily for 1-3 days. We evaluated neurological function deficits and performed hematoxylin and eosin staining. We further calculated the infarct volume. Malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the brain were detected using corresponding kits. The transcription and protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), and NAD(P)H quinone dehydrogenase 1 (NQO1) in brain tissues were analyzed by real-time reverse transcription polymerase chain reaction and western blotting, respectively. The results showed that SPL could remarkably ameliorate neurological functions and pathological damage in brain tissues, reducing the cerebral infarct volume. It also increased the SOD and GPx activities decreased the MDA levels as well as inhibited the expression of (NOX)2 and NOX4. We also found that the mRNA and protein levels of Nrf2, HO-1, and NQO1 in the CIRI mice increased transiently and peaked at 24 h of reperfusion, and then began to decline. SPL could reverse decreasing Nrf2 and HO-1 levels after 24 h. In conclusion, SPL can alleviate CIRI and OS by activating the Nrf2/HO-1 pathway.

Electroacupuncture Pretreatment at Zusanli (ST36) Ameliorates Hepatic Ischemia/Reperfusion Injury in Mice by Reducing Oxidative Stress via Activating Vagus Nerve-Dependent Nrf2 Pathway

Background and Purpose

Current pharmacological approaches to prevent hepatic ischemia/reperfusion injury (IRI) are limited. To mitigate hepatic injury, more research is needed to improve the understanding of hepatic IRI. Depending on traditional Chinese medicine (TCM) theory, acupuncture therapy has been used for the treatment of ischemic diseases with good efficacy. However, the efficacy and mechanism of acupuncture for hepatic IRI are still unclear.

Methods

Blood provided to the left and middle lobe of mice livers was blocked with a non-invasive clamp and then the clamps were removed for reperfusion to establish a liver IRI model. Quantitative proteomics approach was used to evaluate the impact of EA pretreatment on liver tissue proteome in the IRI group. Serum biochemistry was used to detect liver injury, inflammation, and oxidative stress levels. H&E staining and TUNEL staining were used to detect hepatocyte injury and apoptosis. Immunohistochemistry and ELISA were used to detect the degree of inflammatory cell infiltration and the level of inflammation. The anti-inflammatory and antioxidant capacities were detected by Quantitative RT-PCR and Western blotting.

Results

We found that EA at Zusanli (ST36) has a protective effect on hepatic IRI in mice by alleviating oxidative stress, hepatocyte death, and inflammation response. Nuclear factor E2-related factor 2 (Nrf2) as a crucial target was regulated by EA and was then successfully validated. The Nrf2 inhibitor ML385 and cervical vagotomy eliminated the protective effect in the EA treatment group.

Conclusion

This study firstly demonstrated that EA pretreatment at ST36 significantly ameliorates hepatic IRI in mice by inhibiting oxidative stress via activating the Nrf2 signal pathway, which was vagus nerve-dependent.

Chebulic Acid Prevents Hypoxia Insult via Nrf2/ARE Pathway in Ischemic Stroke

Excessive reactive oxygen species (ROS) production contributes to brain ischemia/reperfusion (I/R) injury through many mechanisms including inflammation, apoptosis, and cellular necrosis. Chebulic acid (CA) isolated from Terminalia chebula has been found to have various biological effects, such as antioxidants. In this study, we investigated the mechanism of the anti-hypoxic neuroprotective effect of CA in vitro and in vivo. The results showed that CA could protect against oxygen-glucose deprivation/reoxygenation (OGD/R) induced neurotoxicity in SH-SY5Y cells, as evidenced by the enhancement of cell viability and improvement of total superoxide dismutase (T-SOD) in SH-SY5Y cells. CA also attenuated OGD/R-induced elevations of malondialdehyde (MDA) and ROS in SH-SY5Y cells. Nuclear factor-E2-related factor 2 (Nrf2) is one of the key regulators of endogenous antioxidant defense. CA acted as antioxidants indirectly by upregulating antioxidant-responsive-element (ARE) and Nrf2 nuclear translocation to relieve OGD/R-induced oxidative damage. Furthermore, the results showed that CA treatment resulted in a significant decrease in ischemic infarct volume and improved performance in the motor ability of mice 24 h after stroke. This study provides a new niche targeting drug to oppose ischemic stroke and reveals the promising potential of CA for the control of ischemic stroke in humans.

Role of Nrf2 in aging, Alzheimer's and other neurodegenerative diseases

Nuclear Factor-Erythroid Factor 2 (Nrf2) is an important transcription factor that regulates the expression of large number of genes in healthy and disease states. Nrf2 is made up of 605 amino acids and contains 7 conserved regions known as Nrf2-ECH homology domains. Nrf2 regulates the expression of several key components of oxidative stress, mitochondrial biogenesis, mitophagy, autophagy and mitochondrial function in all organs of the human body, in the peripheral and central nervous systems. Mounting evidence also suggests that altered expression of Nrf2 is largely involved in aging, neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, Huntington's diseases, Amyotrophic lateral sclerosis, Stroke, Multiple sclerosis and others. The purpose of this article is to detail the essential role of Nrf2 in oxidative stress, antioxidative defense, detoxification, inflammatory responses, transcription factors, proteasomal and autophagic/mitophagic degradation, and metabolism in aging and neurodegenerative diseases. This article also highlights the Nrf2 structural and functional activities in healthy and disease states, and also discusses the current status of Nrf2 research and therapeutic strategies to treat aging and neurodegenerative diseases.

Tert-butylhydroquinone abrogates fructose-induced insulin resistance in rats via mitigation of oxidant stress, NFkB-mediated inflammation in the liver but not the skeletal muscle of high fructose drinking rats

The effect of 21% fructose drinking water (FDW) (w/v) on some parameters of metabolic syndrome, hepatic, and skeletal muscular histology of rats was studied using standard techniques. Twenty male albino rats were divided into four groups of 5 rats each in this in vivo study. Group I received distilled water, group 2 received FDW, group 3 received FDW and metformin (300 mg/kg body weight daily, orally), group 4 received FDW and 1% tert-butylhydroquinone feed. FDW changed the serum leptin, triacylglycerol, very low-density lipoprotein, and C-reactive protein levels of the rats, inducing hypertriglyceridemia, oxidative stress, and inflammation in their liver (but not the skeletal muscle) and insulin resistance which were modulated with metformin and tBHQ as corroborated by liver and muscle histology. The study reveals the potentials of metformin and tBHQ in mitigating hepatic and skeletal muscular morphological changes arising from exposure to high fructose drinks. PRACTICAL APPLICATIONS: There has been an increase in the global consumption of fructose (either as a sweetner in beverages or soft and carbonated drinks) in the last few decades and this has been positively correlated with the global increase in metabolic complications. Regular intake of fructose contributes to the pathogenesis of lipid disorders, oxidant stress, and chronic inflammation, which are linked with the metabolic syndrome components (MetS) (obesity, insulin resistance, and cardiovascular diseases) as well as increased morbidity and mortality. Given that the approaches that have been applied to treat the MetS have not been able to totally arrest it, currenty study which showed that tBHQ abrogated fructose-induced insulin resistance, dyslipidemia, hepatic, and skeletal muscular pathology in the rats places tBHQ in the spotlight as a nutraceutical that could be of relevance in mitigating high dietary fructose-induced hepatic and skeletal muscular pathology.

Nrf2 Regulates Oxidative Stress and Its Role in Cerebral Ischemic Stroke

Cerebral ischemic stroke is characterized by acute ischemia in a certain part of the brain, which leads to brain cells necrosis, apoptosis, ferroptosis, pyroptosis, etc. At present, there are limited effective clinical treatments for cerebral ischemic stroke, and the recovery of cerebral blood circulation will lead to cerebral ischemia-reperfusion injury (CIRI). Cerebral ischemic stroke involves many pathological processes such as oxidative stress, inflammation, and mitochondrial dysfunction. Nuclear factor erythroid 2-related factor 2 (Nrf2), as one of the most critical antioxidant transcription factors in cells, can coordinate various cytoprotective factors to inhibit oxidative stress. Targeting Nrf2 is considered as a potential strategy to prevent and treat cerebral ischemia injury. During cerebral ischemia, Nrf2 participates in signaling pathways such as Keap1, PI3K/AKT, MAPK, NF-κB, and HO-1, and then alleviates cerebral ischemia injury or CIRI by inhibiting oxidative stress, anti-inflammation, maintaining mitochondrial homeostasis, protecting the blood-brain barrier, and inhibiting ferroptosis. In this review, we have discussed the structure of Nrf2, the mechanisms of Nrf2 in cerebral ischemic stroke, the related research on the treatment of cerebral ischemia through the Nrf2 signaling pathway in recent years, and expounded the important role and future potential of the Nrf2 pathway in cerebral ischemic stroke.

New insights in ferroptosis: Potential therapeutic targets for the treatment of ischemic stroke

Stroke is a common disease in clinical practice, which seriously endangers people's physical and mental health. The neurovascular unit (NVU) plays a key role in the occurrence and development of ischemic stroke. Different from other classical types of cell death such as apoptosis, necrosis, autophagy, and pyroptosis, ferroptosis is an iron-dependent lipid peroxidation-driven new form of cell death. Interestingly, the function of NVU and stroke development can be regulated by activating or inhibiting ferroptosis. This review systematically describes the NVU in ischemic stroke, provides a comprehensive overview of the regulatory mechanisms and key regulators of ferroptosis, and uncovers the role of ferroptosis in the NVU and the progression of ischemic stroke. We further discuss the latest progress in the intervention of ferroptosis as a therapeutic target for ischemic stroke and summarize the research progress and regulatory mechanism of ferroptosis inhibitors on stroke. In conclusion, ferroptosis, as a new form of cell death, plays a key role in ischemic stroke and is expected to become a new therapeutic target for this disease.

The Role of Concomitant Nrf2 Targeting and Stem Cell Therapy in Cerebrovascular Disease

Despite the reality that a death from cerebrovascular accident occurs every 3.5 min in the United States, there are few therapeutic options which are typically limited to a narrow window of opportunity in time for damage mitigation and recovery. Novel therapies have targeted pathological processes secondary to the initial insult, such as oxidative damage and peripheral inflammation. One of the greatest challenges to therapy is the frequently permanent damage within the CNS, attributed to a lack of sufficient neurogenesis. Thus, recent use of cell-based therapies for stroke have shown promising results. Unfortunately, stroke-induced inflammatory and oxidative damage limit the therapeutic potential of these stem cells. Nuclear factor erythroid 2-related factor 2 (Nrf2) has been implicated in endogenous antioxidant and anti-inflammatory activity, thus presenting an attractive target for novel therapeutics to enhance stem cell therapy and promote neurogenesis. This review assesses the current literature on the concomitant use of stem cell therapy and Nrf2 targeting via pharmaceutical and natural agents, highlighting the need to elucidate both upstream and downstream pathways in optimizing Nrf2 treatments in the setting of cerebrovascular disease.

Tert-butylhydroquinone prevents neuroinflammation and relieves depression via regulation of NLRP3 signaling in mice

Depression is a common psychiatric disorder, which seriously affects people's health and quality of life. Current treatments, which mainly focus on neurotransmitter levels, are not effective in many patients. Recent studies have shown that neuroinflammation has certain correlation with the pathogenesis of depression. Tert-butylhydroquinone (TBHQ) is an antioxidant with an anti-inflammatory effect. The present study evaluated the effects of TBHQ on the improvement of depression-like behaviors induced by lipopolysaccharide (LPS) in mice and its possible mechanism. Behavioral test results showed that TBHQ treatment could significantly improve the depression-like behaviors of mice. Western blot results showed that TBHQ treatment inhibited the protein expression of NLRP3, Caspase-1, IL-1β, and IL-18, which induced by LPS. Immunofluorescence staining results showed that TBHQ treatment inhibited the activation of microglia induced by LPS. These results suggested that, by inhibiting LPS-induced neuroinflammation and microglia activation, TBHQ could effectively improve LPS-induced inflammation-related depression-like behavior through modulating the NLRP3 signaling pathway.

Geraniin Protects against Cerebral Ischemia/Reperfusion Injury by Suppressing Oxidative Stress and Neuronal Apoptosis via Regulation of the Nrf2/HO-1 Pathway

Geraniin, a polyphenol isolated from Phyllanthus amarus, possesses extensive biological and pharmaceutical activities. In this study, we investigated the protective effect against cerebral ischemia/reperfusion (I/R) injury of geraniin and explored its potential mechanism. Middle cerebral artery occlusion/reperfusion (MCAO/R) was used to simulate cerebral I/R injury in vivo, and oxygen-glucose deprivation/reoxygenation (OGD/R) was applied to establish an in vitro model of cerebral I/R injury. In this study, we performed TTC and HE staining and adopted a neurological score method to evaluate the neuroprotective effect of geraniin in vivo and used the CCK-8 assay to assess this effect in vitro. Indices of reactive oxidation capacity were measured in vivo and in vitro to verify the antioxidant capacity of geraniin. TUNEL staining and flow cytometry were applied to measure the apoptosis rate, and Western blotting was performed to assess the expression of apoptosis-related proteins. Finally, the expression of Nrf2 and HO-1 was evaluated in vivo and in vitro by Western blotting. Geraniin significantly reduced the infarct volume, decreased neurological deficit scores, alleviated pathological changes in neurons, and increased the cell survival rate. Geraniin increased the activity of superoxide dismutase (SOD) and decreased the activity of lactate dehydrogenase (LDH) and the contents of malondialdehyde (MDA), nitric oxide (NO), and neuronal nitric oxide synthase (nNOS) in vivo and in vitro. In addition, geraniin significantly reduced the apoptosis. Furthermore, geraniin also evidently increased Nrf2 (total and nuclear) and HO-1 protein expression in vivo and in vitro. Collectively, these results imply that geraniin may exert a protective effect against cerebral I/R injury by suppressing oxidative stress and neuronal apoptosis. The mechanism underlying the protective effect of geraniin is associated with activation of the Nrf2/HO-1 pathway. Our results indicate that geraniin may be a potential drug candidate for the treatment of ischemic stroke.

RETRACTED: TRIM21 deficiency confers protection from OGD/R-induced oxidative and inflammatory damage in cultured hippocampal neurons through regulation of the Keap1/Nrf2 pathway

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The authors have requested that this paper be retracted as they were unable to repeat some results reported in this paper under the same conditions. In Figure 1D, they found that TRIM21 siRNA-1 could not silence the expression of TIRM21. Therefore, the subsequent results were no longer reliable. The authors apologize for any inconvenience this retraction may cause for readers.

Activation of AdipoR1 with rCTRP9 Preserves BBB Integrity through the APPL1/AMPK/Nrf2 Signaling Pathway in ICH Mice

Background

The disruption of the blood brain barrier (BBB) is the key factor leading to neurological impairment after intracerebral hemorrhage (ICH) injury. Adiponectin receptor 1 (AdipoR1) has an important effect contributing to the integrity of BBB. As a homologue of adiponectin, recombinant C1q/TNF-related protein 9 (rCTRP9) has neuroprotective effect in cerebrovascular diseases. The aim of this study was to investigate the protective effect of AdipoR1 activation with rCTRP9 on BBB integrity after ICH injury and the potential mechanisms.

Methods

177 male mice were subjected in this study. ICH was induced by injecting collagenase into the right basal ganglia. rCTRP9 was treated intranasally at 1 hour after ICH. Selective siRNA was administered prior to ICH. Western blot, immunofluorescence staining, neurobehavioral tests, and BBB permeability were evaluated.

Results

ICH increased the expression of endogenous AdipoR1 and CTRP9. Administration of rCTRP9 ameliorated neurological deficits and reduced the BBB permeability at 24 hours in ICH mice. Furthermore, rCTRP9 promoted the expression of AdipoR1, APPL1, p-AMPK, Nrf2, and tight junctional proteins. The intervention of specific siRNA of AdipoR1, APPL1, and p-AMPK reversed the protective effects of rCTRP9.

Conclusions

Activation of AdipoR1 with rCTRP9 improved neurological functions and preserved BBB integrity through the APPL1/AMPK/Nrf2 signaling pathway in ICH mice. Therefore, CTRP9 could serve as a promising therapeutic method to alleviate BBB injury following ICH in patients.

Systematic Review of Calcium Channels and Intracellular Calcium Signaling: Relevance to Pesticide Neurotoxicity

Pesticides of different chemical classes exert their toxic effects on the nervous system by acting on the different regulatory mechanisms of calcium (Ca2+) homeostasis. Pesticides have been shown to alter Ca2+ homeostasis, mainly by increasing its intracellular concentration above physiological levels. The pesticide-induced Ca2+ overload occurs through two main mechanisms: the entry of Ca2+ from the extracellular medium through the different types of Ca2+ channels present in the plasma membrane or its release into the cytoplasm from intracellular stocks, mainly from the endoplasmic reticulum. It has also been observed that intracellular increases in the Ca2+ concentrations are maintained over time, because pesticides inhibit the enzymes involved in reducing its levels. Thus, the alteration of Ca2+ levels can lead to the activation of various signaling pathways that generate oxidative stress, neuroinflammation and, finally, neuronal death. In this review, we also discuss some proposed strategies to counteract the detrimental effects of pesticides on Ca2+ homeostasis.

The Antioxidant Transcription Factor Nrf2 in Cardiac Ischemia-Reperfusion Injury

Nuclear factor erythroid-2 related factor 2 (Nrf2) is a transcription factor that controls cellular defense responses against toxic and oxidative stress by modulating the expression of genes involved in antioxidant response and drug detoxification. In addition to maintaining redox homeostasis, Nrf2 is also involved in various cellular processes including metabolism and inflammation. Nrf2 activity is tightly regulated at the transcriptional, post-transcriptional and post-translational levels, which allows cells to quickly respond to pathological stress. In the present review, we describe the molecular mechanisms underlying the transcriptional regulation of Nrf2. We also focus on the impact of Nrf2 in cardiac ischemia-reperfusion injury, a condition that stimulates the overproduction of reactive oxygen species. Finally, we analyze the protective effect of several natural and synthetic compounds that induce Nrf2 activation and protect against ischemia-reperfusion injury in the heart and other organs, and their potential clinical application.

Epigenetic Regulations of Microglia/Macrophage Polarization in Ischemic Stroke

Ischemic stroke is one of the leading causes of death and disability worldwide. Microglia/macrophages (MMs)-mediated neuroinflammation contributes significantly to the pathological process of ischemic brain injury. Microglia, serving as resident innate immune cells in the central nervous system, undergo pro-inflammatory phenotype or anti-inflammatory phenotype in response to the microenvironmental changes after cerebral ischemia. Emerging evidence suggests that epigenetics modifications, reversible modifications of the phenotype without changing the DNA sequence, could play a pivotal role in regulation of MM polarization. However, the knowledge of the mechanism of epigenetic regulations of MM polarization after cerebral ischemia is still limited. In this review, we present the recent advances in the mechanisms of epigenetics involved in regulating MM polarization, including histone modification, non-coding RNA, and DNA methylation. In addition, we discuss the potential of epigenetic-mediated MM polarization as diagnostic and therapeutic targets for ischemic stroke. It is valuable to identify the underlying mechanisms between epigenetics and MM polarization, which may provide a promising treatment strategy for neuronal damage after cerebral ischemia.

Systems Biology and Chemoinformatics-Based Strategies to Explore the Biological Mechanism of Fugui Wenyang Decoction in Treating Vascular Dementia Rats

OBJECTIVE

To explore the biological mechanism of Fugui Wenyang Decoction (FGWYD) in treating vascular dementia (VD) rats based on systems pharmacology, proteomics, and a multidirectional pharmacology integration strategy.

METHODS

Chemoinformatics was utilized to construct and analyze the FGWYD-VD protein-protein interaction (PPI) network. Then, the total protein in the brain tissue of the infarcted side of the rat was extracted for protein identification, pattern identification, and protein quantitative analysis. The differentially expressed proteins are analyzed by bioinformatics. Finally, the important proteins in the oxidative stress-related biological process proteins and indicators were detected through experimental pharmacology to verify the findings of systems biology and chemoinformatics.

RESULTS

There were a total of 73 FGWYD components with 245 FGWYD and 145 VD genes. The results of GO enrichment analysis and pathway enrichment analysis showed that MBHD may regulate the inflammation module, oxidative stress, the synaptic plasticity regulation module, and the neuronal apoptosis section module. Compared with the sham operation group, there were 23 upregulated proteins and 17 downregulated proteins in the model group (P < 0.05). Compared with the model group, there were 16 upregulated proteins and 10 downregulated proteins in the FGWYD group (P < 0.05). Bioinformatics analysis shows that those proteins were closely related to processes such as inflammation, oxidative stress, neuronal apoptosis, neuronal growth and differentiation, signaling pathways, and transcriptional regulation. Multidirectional pharmacology further verified the neuroprotective mechanism of the Nrf2/HO-1 pathway in FGWYD treatment of VD.

CONCLUSION

The mechanism of FGWYD in the treatment of VD may be related to inflammation, oxidative stress, angiogenesis, and neuronal apoptosis.

The Nrf2 Pathway in Ischemic Stroke: A Review

Ischemic stroke, characterized by the sudden loss of blood flow in specific area(s) of the brain, is the leading cause of permanent disability and is among the leading causes of death worldwide. The only approved pharmacological treatment for acute ischemic stroke (intravenous thrombolysis with recombinant tissue plasminogen activator) has significant clinical limitations and does not consider the complex set of events taking place after the onset of ischemic stroke (ischemic cascade), which is characterized by significant pro-oxidative events. The transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2), which regulates the expression of a great number of antioxidant and/or defense proteins, has been pointed as a potential pharmacological target involved in the mitigation of deleterious oxidative events taking place at the ischemic cascade. This review summarizes studies concerning the protective role of Nrf2 in experimental models of ischemic stroke, emphasizing molecular events resulting from ischemic stroke that are, in parallel, modulated by Nrf2. Considering the acute nature of ischemic stroke, we discuss the challenges in using a putative pharmacological strategy (Nrf2 activator) that relies upon transcription, translation and metabolically active cells in treating ischemic stroke patients.

Potential therapeutic effects of Nrf2 activators on intracranial hemorrhage

Intracranial hemorrhage (ICH) is a devastating disease which induces high mortality and poor outcomes including severe neurological dysfunctions. ICH pathology is divided into two types: primary brain injury (PBI) and secondary brain injury (SBI). Although there are numerous preclinical studies documenting neuroprotective agents in experimental ICH models, no effective drugs have been developed for clinical use due to complicated ICH pathology. Oxidative and inflammatory stresses play central roles in the onset and progression of brain injury after ICH, especially SBI. Nrf2 is a crucial transcription factor in the anti-oxidative stress defense system. Under normal conditions, Nrf2 is tightly regulated by the Keap1. Under ICH pathological conditions, such as overproduction of reactive oxygen species (ROS), Nrf2 is translocated into the nucleus where it up-regulates the expression of several anti-oxidative phase II enzymes such as heme oxygenase-1 (HO-1). Recently, many reports have suggested the therapeutic potential of Nrf2 activators (including natural or synthesized compounds) for treating neurodegenerative diseases. Moreover, several Nrf2 activators attenuate ischemic stroke-induced brain injury in several animal models. This review summarizes the efficacy of several Nrf2 activators in ICH animal models. In the future, Nrf2 activators might be approved for the treatment of ICH patients.

Crosstalk between Oxidative Stress and Ferroptosis/Oxytosis in Ischemic Stroke: Possible Targets and Molecular Mechanisms

Oxidative stress is a key cause of ischemic stroke and an initiator of neuronal dysfunction and death, mainly through the overproduction of peroxides and the depletion of antioxidants. Ferroptosis/oxytosis is a unique, oxidative stress-induced cell death pathway characterized by lipid peroxidation and glutathione depletion. Both oxidative stress and ferroptosis/oxytosis have common molecular pathways. This review summarizes the possible targets and the mechanisms underlying the crosstalk between oxidative stress and ferroptosis/oxytosis in ischemic stroke. This knowledge might help to further understand the pathophysiology of ischemic stroke and open new perspectives for the treatment of ischemic stroke.

Traumatic Brain Injury: Mechanistic Insight on Pathophysiology and Potential Therapeutic Targets

Traumatic brain injury (TBI) causes brain damage, which involves primary and secondary injury mechanisms. Primary injury causes local brain damage, while secondary damage begins with inflammatory activity followed by disruption of the blood-brain barrier (BBB), peripheral blood cells infiltration, brain edema, and the discharge of numerous immune mediators including chemotactic factors and interleukins. TBI alters molecular signaling, cell structures, and functions. Besides tissue damage such as axonal damage, contusions, and hemorrhage, TBI in general interrupts brain physiology including cognition, decision-making, memory, attention, and speech capability. Regardless of the deep understanding of the pathophysiology of TBI, the underlying mechanisms still need to be assessed with a desired therapeutic agent to control the consequences of TBI. The current review gives a brief outline of the pathophysiological mechanism of TBI and various biochemical pathways involved in brain injury, pharmacological treatment approaches, and novel targets for therapy.

The Role of Non-Coding RNAs in the Neuroprotective Effects of Glutathione

The establishment of antioxidative defense systems might have been mandatory for most living beings with aerobic metabolisms, because oxygen consumption produces adverse byproducts known as reactive oxygen species (ROS). The brain is especially vulnerable to the effect of ROS, since the brain has large amounts of unsaturated fatty acids, which are a target of lipid oxidation, as well as comparably high-energy consumption compared to other organs that results in ROS release from mitochondria. Thus, dysregulation of the synthesis and/or metabolism of antioxidants-particularly glutathione (GSH), which is one of the most important antioxidants in the human body-caused oxidative stress states that resulted in critical diseases, including neurodegenerative diseases in the brain. GSH plays crucial roles not only as an antioxidant but also as an enzyme cofactor, cysteine storage form, the major redox buffer, and a neuromodulator in the central nervous system. The levels of GSH are precisely regulated by uptake systems for GSH precursors as well as GSH biosynthesis and metabolism. The rapid advance of RNA sequencing technologies has contributed to the discovery of numerous non-coding RNAs with a wide range of functions. Recent lines of evidence show that several types of non-coding RNAs, including microRNA, long non-coding RNA and circular RNA, are abundantly expressed in the brain, and their activation or inhibition could contribute to neuroprotection through the regulation of GSH synthesis and/or metabolism. Interestingly, these non-coding RNAs play key roles in gene regulation and growing evidence indicates that non-coding RNAs interact with each other and are co-regulated. In this review, we focus on how the non-coding RNAs modulate the level of GSH and modify the oxidative stress states in the brain.

Sinomenine activation of Nrf2 signaling prevents inflammation and cerebral injury in a mouse model of ischemic stroke

Sinomenine (SINO), which is used clinically to treat rheumatoid arthritis and neuralgia, is derived from the root and stems of Sinomenium acutum. SINO has been reported to exert analgesic, sedative and anti-inflammatory effects, and provides a protective role against shock and organ damage. Studies have suggested that SINO primarily exerts it anti-inflammatory function by inhibiting NF-κB signaling. There is also evidence to indicate that SINO may regulate inflammation Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling. The present study aimed to investigate whether the anti-inflammatory and cerebral protective effects of SINO were induced through Nrf2 both in vitro and in vivo. The results revealed that SINO significantly upregulated Nrf2 protein expression levels, increased Nrf2 nuclear translocation and the upregulated the protein expression levels of downstream factors. The treatment of a middle cerebral artery occlusion model mice with SINO effectively reduced cerebral damage and inflammation, and restored the balance in cerebral oxidative stress. In addition, SINO treatment also promoted Nrf2-dependent microglia M1/M2 polarization and inhibited the phosphorylation of IκBα as well as NF-κB nuclear translocation. This revealed an important upstream event that contributed to its anti-inflammatory and cerebral tissue protective effects. In conclusion, the findings of the present study identified a novel pathway through which SINO may exert its anti-inflammatory and cerebral protective functions, and provided a molecular basis for the potential applications of SINO in the treatment of cerebral inflammatory disorders.

Functional predication of differentially expressed circRNAs/lncRNAs in the prefrontal cortex of Nrf2-knockout mice

In the central nervous system, nuclear factor erythroid-2-related factor 2 (Nrf2) protects neurons from oxidant injury, thereby ameliorating neurodegeneration. We explored the key circular RNAs (circRNAs) and long non-coding RNAs (lncRNAs) involved in Nrf2-induced neuroprotection. We used microarrays to examine the circRNAs (DEcircRNAs), lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) differentially expressed between Nrf2 (+/+) and Nrf2 (-/-) mice and identified DEcircRNA/DElncRNA-miRNA-DEmRNA interaction networks. In total, 197 DEcircRNAs, 685 DElncRNAs and 356 DEmRNAs were identified in prefrontal cortical tissues from Nrf2 (-/-) mice. The expression patterns of selected DEcircRNAs (except for mmu_circ_0003404) and DElncRNAs in qRT-PCR analyses were generally consistent with the microarray analysis results. Functional annotation of the DEmRNAs in the DEcircRNA/DElncRNA-miRNA-DEmRNA networks indicated that five non-coding RNAs (mmu_circ_0000233, ENSMUST00000204847, NONMMUT024778, NONMMUT132160 and NONMMUT132168) may contribute to Nrf2 activity, with the help of mmu_circ_0015035 and NONMMUT127961. The results also revealed that four non-coding RNAs (cicRNA.20127, mmu_circ_0012936, ENSMUST00000194077 and NONMMUT109267) may influence glutathione metabolism. Additionally, 44 DEcircRNAs and 7 DElncRNAs were found to possess coding potential. These findings provide clues to the molecular pathways through which Nrf2 protects neurons.

Sulforaphane Protects Piglet Brains from Neonatal Hypoxic-Ischemic Injury

The striatal, primary sensorimotor cortical, and thalamic neurons are highly vulnerable to hypoxia-ischemia (HI) in term newborns. In a piglet model of HI that exhibits similar selective regional vulnerability, we tested the hypothesis that early treatment with sulforaphane, an activator of the Nrf2 transcription factor, protects vulnerable neurons from HI injury. Anesthetized piglets (aged 3-7 days) were subjected to 45 min of hypoxia and 7 min of airway occlusion. At 15 min after resuscitation, the piglets received intravenous vehicle or sulforaphane. At 4 days of recovery, the density of viable neurons in the putamen of vehicle-treated piglets was 31 ± 34% (±SD) that of sham-operated controls. Treatment with sulforaphane significantly increased viability to 77 ± 31%. In the sensorimotor cortex, neuronal viability was also increased; it was 59 ± 35% in the vehicle-treated and 89 ± 15% in the sulforaphane-treated animals. Treatment with sulforaphane increased the nuclear Nrf2 and γ-glu-tamylcysteine synthetase expression at 6 h of recovery in these regions. We conclude that systemic administration of sulforaphane 15 min after HI can induce the translocation of Nrf2 to the nucleus, increase expression of an enzyme involved in glutathione synthesis, and salvage neurons in the highly vulnerable putamen and sensorimotor cortex in a large-animal model of HI. Therefore, targeting Nrf2 activation soon after recovery from HI is a feasible approach for neuroprotection in the newborn brain.

Effect of the unfolded protein response and oxidative stress on mutagenesis in CSF3R: a model for evolution of severe congenital neutropenia to myelodysplastic syndrome/acute myeloid leukemia

Severe congenital neutropenia (SCN) is a rare blood disorder characterised by abnormally low levels of circulating neutrophils. The most common recurrent mutations that cause SCN involve neutrophil elastase (ELANE). The treatment of choice for SCN is the administration of granulocyte-colony stimulating factor (G-CSF), which increases the neutrophil number and improves the survival and quality of life. Long-term survival is however linked to the development of myelodysplastic syndrome/acute myeloid leukemia (MDS/AML). About 70% of MDS/AML patients acquire nonsense mutations affecting the cytoplasmic domain of CSF3R (the G-CSF receptor). About 70% of SCN patients with AML harbour additional mutations in RUNX1. We hypothesised that this coding region of CSF3R constitutes a hotspot vulnerable to mutations resulting from excessive oxidative stress or endoplasmic reticulum (ER) stress. We used the murine Ba/F3 cell line to measure the effect of induced oxidative or ER stress on the mutation rate in our hypothesised hotspot of the exogenous human CSF3R, the corresponding region in the endogenous Csf3r, and Runx1. Ba/F3 cells transduced with the cDNA for partial C-terminal of CSF3R fused in-frame with a green fluorescent protein (GFP) tag were subjected to stress-inducing treatment for 30 days (~51 doubling times). The amplicon-based targeted deep sequencing data for days 15 and 30 samples show that although there was increased mutagenesis observed in all the three genes of interest (partial CSF3R, Csf3r and Runx1), there were more mutations in the GFP region compared with the partial CSF3R region. Our findings also indicate that there is no correlation between the stress-inducing chemical treatments and mutagenesis in Ba/F3 cells. Our data suggest that oxidative or ER stress induction does not promote genomic instability, affecting partial C-terminal of the transduced CSF3R, the endogenous Csf3R and the endogenous Runx1 in Ba/F3 cells that could account for these targets to being mutational hotspots. We conclude that other mechanisms to acquire mutations of CSF3R that help drive the evolution of SCN to MDS/AML.

Tim-3 deteriorates neuroinflammatory and neurocyte apoptosis after subarachnoid hemorrhage through the Nrf2/HMGB1 signaling pathway in rats

Inflammation is known to play an important role in early brain injury (EBI) after subarachnoid hemorrhage (SAH). T cell immunoglobulin and mucin domain-3 (Tim-3) has emerged as a critical regulator of adaptive and innate immune responses, and has been identified to play a vital role in certain inflammatory diseases; The present study explored the effect of Tim-3 on inflammatory responses and detailed mechanism in EBI following SAH. We investigated the effects of Tim-3 on SAH models established by endovascular puncture method in Sprague–Dawley rats. The present studies revealed that SAH induced a significant inflammatory response and significantly increased Tim-3 expression. Tim-3-AAV administration aggravated neurocyte apoptosis, brain edema, blood-brain barrier permeability, and neurological dysfunction; significantly inhibited Nrf2 expression; and increased HMGB1 expression and secretion of pro-inflammatory cytokines, such as tumor necrosis factor alpha, interleukin (IL)-1 beta, IL-17, and IL-18. However, Tim-3 siRNA or NK252 administration abolished the pro-inflammatory effects of Tim-3. Our results indicate a function for Tim-3 as a molecular player that links neuroinflammation and brain damage after SAH. We reveal that Tim-3 overexpression deteriorates neuroinflammatory and neurocyte apoptosis after subarachnoid hemorrhage through the Nrf2/HMGB1 signaling pathway in rats.