Oxidative Stress in Ischemia/Reperfusion Injuries following Acute Ischemic Stroke

Zinc sulfide nanoparticles serve as gas slow-release bioreactors for H2S therapy of ischemic stroke

Stroke is one of the leading causes of death and disability in the world. Ischemic stroke causes overproduction of reactive oxygen/nitrogen species (RONS) after reperfusion, triggering inflammatory responses that further leads to cell damage. In order to develop novel neuroprotective materials, we synthesized zinc sulfide nanoparticles (ZnS NPs) to function as gas slow-release bioreactors, showcasing stable and sustained H2S release while effectively removing RONS. In cultured cells, ZnS NPs can reduce the oxidative damage caused by oxygen-glucose deprivation and reoxygenation (OGD/R), promote the expression of p-AMPK, enhance microglia M2 polarization, decrease inflammatory factors and reduce neuronal apoptosis. Additionally, it increases the proliferation and migration of endothelial cells, promoting the formation of new neurovascular units by regulating the protein of p-AKT. In mice with ischemic stroke induced by middle cerebral artery occlusion/reperfusion (MCAO/R), ZnS NPs significantly reduce the infarct area and restore the mobility of mice owing to the slow release of H2S. In summary, our results indicate that ZnS NPs can be used as H2S slow-release bioreactors, offering a potentially innovative approach to treat ischemia-reperfusion injury caused by stroke.

Caffeine improves hypoxia/reoxygenation induced neuronal cell injury through inhibiting cellular ferroptosis: an in vitro study

OBJECTIVE

Ferroptosis, a regulated cell death pathway driven by lipid peroxidation and iron overload, is implicated in neuronal injury caused by hypoxia/reoxygenation (H/R). Caffeine, a widely consumed psychoactive compound, has shown neuroprotective effects in various central nervous system disorders, but its role in regulating ferroptosis remains unclear. This study investigates the neuroprotective effects of caffeine on ferroptosis and its regulation of ACSL4, a key ferroptosis-related protein.

METHODS

Molecular docking was performed to evaluate the interaction between caffeine and ferroptosis-related proteins ACSL4 and GPX4. HT-22 cells were subjected to H/R to establish an in vitro injury model, followed by treatment with caffeine at varying concentrations. ACSL4 was silenced or overexpressed to explore its role in caffeine-mediated ferroptosis regulation. Cell viability, inflammatory cytokines, ferroptosis markers, and mitochondrial function were assessed.

RESULTS

Molecular docking revealed favorable binding affinities of caffeine with ACSL4 (-5.6 kcal/mol) and GPX4 (-4.6 kcal/mol). Caffeine treatment dose-dependently improved cell viability, reduced TNF-α, IL-1β, and IL-6 levels, and inhibited ferroptosis by downregulating ACSL4 and upregulating GPX4. Overexpression of ACSL4 reversed these protective effects, increasing lipid peroxidation markers (iron, Fe2+, ROS, and MDA) and reducing GSH levels and mitochondrial membrane potential. Conversely, silencing ACSL4 enhanced caffeine's protective effects, confirming its role as a critical target of caffeine-mediated ferroptosis inhibition.

CONCLUSION

Caffeine protects against H/R-induced neuronal injury by regulating ACSL4-mediated ferroptosis, reducing oxidative stress and inflammation. These findings highlight ACSL4 as a therapeutic target and provide mechanistic insights into caffeine's neuroprotective potential.

Differentially Expressed Genes in Rat Brain Regions with Different Degrees of Ischemic Damage

Ischemic stroke is a multifactorial disease that leads to brain tissue damage and severe neurological deficit. Transient middle cerebral artery occlusion (tMCAO) models are actively used for the molecular, genetic study of stroke. Previously, using high-throughput RNA sequencing (RNA-Seq), we revealed 3774 differentially expressed genes (DEGs) in the penumbra-associated region of the frontal cortex (FC) of rats 24 h after applying the tMCAO model. Here, we studied the gene expression pattern in the striatum that contained an ischemic focus. Striatum samples were obtained from the same rats from which we previously obtained FC samples. Therefore, we compared DEG profiles between two rat brain tissues 24 h after tMCAO. Tissues were selected based on magnetic resonance imaging (MRI) and histological examination (HE) data. As a result, 4409 DEGs were identified 24 h after tMCAO in striatum. Among them, 2609 DEGs were overlapped in the striatum and FC, whereas more than one thousand DEGs were specific for each studied tissue. Furthermore, 54 DEGs exhibited opposite changes at the mRNA level in the two brain tissues after tMCAO. Thus, the spatial regulation of the ischemic process in the ipsilateral hemisphere of rat brain at the transcriptome level was revealed. We believe that the targeted adjustment of the genome responses identified can be the key for the induction of regeneration processes in brain cells after stroke.

Glial Cell Reprogramming in Ischemic Stroke: A Review of Recent Advancements and Translational Challenges

Ischemic stroke, the second leading cause of death worldwide and the leading cause of long-term disabilities, presents a significant global health challenge, particularly in aging populations where the risk and severity of cerebrovascular events are significantly increased. The aftermath of stroke involves neuronal loss in the infarct core and reactive astrocyte proliferation, disrupting the neurovascular unit, especially in aged brains. Restoring the balance between neurons and non-neuronal cells within the perilesional area is crucial for post-stroke recovery. The aged post-stroke brain mounts a fulminant proliferative astroglial response, leading to gliotic scarring that prevents neural regeneration. While countless therapeutic techniques have been attempted for decades with limited success, alternative strategies aim to transform inhibitory gliotic tissue into an environment conducive to neuronal regeneration and axonal growth through genetic conversion of astrocytes into neurons. This concept gained momentum following discoveries that in vivo direct lineage reprogramming in the adult mammalian brain is a feasible strategy for reprogramming non-neuronal cells into neurons, circumventing the need for cell transplantation. Recent advancements in glial cell reprogramming, including transcription factor-based methods with factors like NeuroD1, Ascl1, and Neurogenin2, as well as small molecule-induced reprogramming and chemical induction, show promise in converting glial cells into functional neurons. These approaches leverage the brain's intrinsic plasticity for neuronal replacement and circuit restoration. However, applying these genetic conversion therapies in the aged, post-stroke brain faces significant challenges, such as the hostile inflammatory environment and compromised regenerative capacity. There is a critical need for safe and efficient delivery methods, including viral and non-viral vectors, to ensure targeted and sustained expression of reprogramming factors. Moreover, addressing the translational gap between preclinical successes and clinical applications is essential, emphasizing the necessity for robust stroke models that replicate human pathophysiology. Ethical considerations and biosafety concerns are critically evaluated, particularly regarding the long-term effects and potential risks of genetic reprogramming. By integrating recent research findings, this comprehensive review provides an in-depth understanding of the current landscape and future prospects of genetic conversion therapy for ischemic stroke rehabilitation, highlighting the potential to enhance personalized stroke management and regenerative strategies through innovative approaches.

Elemene mitigates oxidative stress and neuronal apoptosis induced by cerebral ischemia-reperfusion injury through the regulation of glutathione metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

Chinese materia medica (CMM) has a long history and extensive experience in treating ischemic stroke. Wen Ezhu, the rhizome of Curcuma wenyujin Y.H. Chen et C. Ling, is renowned for promoting blood circulation, dispersing blood stasis, alleviating pain, and eliminating masses. Promoting blood circulation and removing blood stasis are essential principles in Traditional Chinese Medicine for treating stroke. Consequently, Wen Ezhu is frequently used in clinical practice as a key CMM for treating stroke. The Elemene active fraction (ELE), a sesquiterpene compound extracted from Wen Ezhu, primarily consists of β-Elemene. It also contains β-Caryophyllene, γ-Elemene, and δ-Elemene isomers. ELE has shown potential pharmacological effects in various diseases, including ischemic stroke. However, its precise mechanism of action in treating stroke remains to be confirmed.

AIM OF THE STUDY

To explore the therapeutic potential of ELE in acute ischemic stroke and elucidate its underlying mechanisms.

MATERIALS AND METHODS

A rat model of middle cerebral artery occlusion reperfusion (MCAO/R) was used to evaluate ELE's effects. Therapeutic efficacy was assessed through mNSS scoring, magnetic resonance imaging (MRI), tetrazolium chloride (TTC) staining, Hematoxylin and eosin (H&E), and Nissl staining. Non-targeted metabolomics identified key pathways, confirmed using biochemical analysis, immunohistochemistry, and Western blotting. ROS levels and apoptosis-related proteins were also evaluated.

RESULTS

Our findings show that ELE administration significantly reduced the cerebral infarct area and lowered modified neurological severity scores (mNSS) in animals, indicating a strong neuroprotective effect. Metabolomics results highlight the glutathione (GSH) metabolic pathway as a key mechanism through which ELE exerts its therapeutic effects. Specifically, ELE upregulates glutathione reductase (GR) protein expression and downregulates glutathione peroxidase (GPX) expression. The regulatory process of ELE decreases oxidized glutathione (GSSG) levels and increases GSH levels, effectively reducing oxidative stress damage (lower reactive oxygen species levels) during CI/RI. This results in the downregulation of the pro-apoptotic protein Bax and the upregulation of the pro-survival protein Bcl-2, thus reducing neuronal apoptosis.

CONCLUSIONS

ELE protects neurons in MCAO/R rats through the GSH metabolism pathway, balancing GSH and GSSG levels to mitigate oxidative stress and enhance neuroprotection in cerebral ischemia/reperfusion injury.

Promotion of nitric oxide production: mechanisms, strategies, and possibilities

The discovery of nitric oxide (NO) and the role of endothelial cells (ECs) in its production has revolutionized medicine. NO can be produced by isoforms of NO synthases (NOS), including the neuronal (nNOS), inducible (iNOS), and endothelial isoforms (eNOS), and via the non-classical nitrate-nitrite-NO pathway. In particular, endothelium-derived NO, produced by eNOS, is essential for cardiovascular health. Endothelium-derived NO activates soluble guanylate cyclase (sGC) in vascular smooth muscle cells (VSMCs), elevating cyclic GMP (cGMP), causing vasodilation. Over the past four decades, the importance of this pathway in cardiovascular health has fueled the search for strategies to enhance NO bioavailability and/or preserve the outcomes of NO's actions. Currently approved approaches operate in three directions: 1) providing exogenous NO, 2) promoting sGC activity, and 3) preventing degradation of cGMP by inhibiting phosphodiesterase 5 activity. Despite clear benefits, these approaches face challenges such as the development of nitrate tolerance and endothelial dysfunction. This highlights the need for sustainable options that promote endogenous NO production. This review will focus on strategies to promote endogenous NO production. A detailed review of the mechanisms regulating eNOS activity will be first provided, followed by a review of strategies to promote endogenous NO production based on the levels of available preclinical and clinical evidence, and perspectives on future possibilities.

Pathophysiology of cerebral ischemia-reperfusion injury: An overview of oxidative stress and plant-based therapeutic approaches

Stroke is a debilitating neurological disorder that causes substantial morbidity and mortality on a global scale. Ischemic stroke, the most common type, occurs when the brain's blood supply is interrupted. Oxidative stress is a key factor in stroke pathology, contributing to inflammation and neuronal cell death. As a result, there is increasing interest in the potential of plant extracts, which have been used in traditional medicine for centuries and are generally considered safe, to serve as alternative or complementary treatments for stroke. The plant extracts can target multiple pathological processes, including oxidative stress, offering neuroprotective effects. The development of highly efficient, low-toxicity, and cost-effective natural products is crucial for enhancing stroke treatment options. In this review, we examine 60 plant extracts that have been focused on the studies published from year 2000 to 2024 along with the studies' experimental models, dosages, and results. The plant extracts hold promise in modulating cerebral ischemia-reperfusion injury through counteraction of relevant pathophysiologic processes such as oxidative stress.

Metabolomic and transcriptomic analyses revealed potential mechanisms of Anchusa italica Retz. in alleviating cerebral ischemia-reperfusion injury via Wnt/β-catenin pathway modulation

Anchusa italica Retz. (AIR), a traditional herbal remedy, is commonly applied in managing heart and brain disorders. However, its specific function and mechanism in acute cerebral ischemia-reperfusion injury (CIRI) are not fully understood. This research focused on the interventional effects and potential mechanisms of AIR extract (AIRE) in a rat model of CIRI. The model was established using the filament occlusion method, which involved blocking the middle cerebral artery for 1.5 h and then removing the filament to restore blood flow. Transcriptomic and metabolomic analyses were conducted to explore the molecular pathways and metabolites affected by AIRE. ATP level was measured using an ATP assay kit. Additionally, RT-qPCR and western blot tests were conducted to evaluate the influence of AIRE on the Wnt signaling pathway and mitochondrial function. Transcriptomic and metabolomic analyses indicated that AIRE regulated the Wnt signaling pathway in CIRI and modulated metabolites associated with mitochondrial energy metabolism, such as citrate and succinate. ATP assay result demonstrated that AIRE enhanced ATP production in CIRI. Further, RT-qPCR and western blot analyses revealed that AIRE activated the Wnt/β-catenin signaling pathway and corrected mitochondrial dysfunction. These results proposed that AIRE mitigated mitochondrial energy metabolism deficits in CIRI via the Wnt/β-catenin pathway. By restoring the balance of mitochondrial function and energy metabolism, AIRE might offer a potentially therapeutic strategy for addressing CIRI.

Nanocurcumin in myocardial infarction therapy: emerging trends and future directions

Myocardial infarction (MI) is the leading cause of morbidity and mortality worldwide. Curcumin has been observed to significantly reduce pathological processes associated with MI. Its clinical application is limited due to its low bioavailability, rapid degradation, and poor solubility. Advancements in nanotechnology can be used to enhance its therapeutic potentials in MI. Curcumin nano-formulation enhances its solubility, stability, and bioavailability, allowing more precise delivery to ischemic cardiac tissue. Curcumin nanoparticles have been observed to successfully reduce infarct size, maintain heart function by modulating essential molecular pathways in MI. Its liposomal formulations provide sustained release and higher tissue penetration with improved pharmacokinetics and enhanced therapeutic efficacy. Preclinical studies revealed that nanocurcumin drastically lower oxidative stress indicators, inflammatory cytokines, and cardiac damage. Micelles composed of polymers have demonstrated high biocompatibility and targeting capabilities with increased cardio-protective effects. Research and clinical trials are essential for comprehensive analysis and efficacy of curcumin-based nano-therapeutics in cardiovascular condition and lowering risk of MI.

Paraoxonase 1 ameliorates neurological symptoms and motor coordination impairment caused by cerebral ischemia-reperfusion injury

The anti-atherosclerotic effects of high-density lipoprotein (HDL) prevent the onset of cerebral infarction and provide cerebroprotective effects against ischemia-reperfusion injury. These inhibitory effects have been attributed to its antioxidant, anti-inflammatory, and antithrombotic properties. However, pharmacotherapeutic strategies to clinically realize these effects have not been demonstrated. Therefore, we aimed to develop paraoxonase 1 (PON1), a hydrolytic enzyme associated with HDL that exhibits antioxidant and anti-inflammatory effects, as a novel therapeutic agent against ischemia-reperfusion injury in cerebral infarction. We established a method to extract PON1 from human plasma with high purity and recovery while maintaining its activity. The purified PON1 exhibited antioxidant activity against human-derived LDL and HDL. Furthermore, PON1 actively suppressed the oxidation chain reaction by hydrolyzing lipid peroxides. The HDL-binding ability of PON1 was evaluated based on its activity in fractionated HDL from mice administered PON1 intravenously, which showed that most intravenously administered PON1 specifically bound to HDL. The cerebroprotective effect of intravenously administered PON1 was assessed using a mouse middle cerebral artery ischemia-reperfusion model by measuring infarct volume, long-term neurological scores, and walking time on a rotarod. Administration of PON1 after reperfusion reduced infarct volume 24 h after ischemia-reperfusion. Additionally, daily administration of PON1 for three days significantly improved neurological scores and walking time by approximately one month. Analysis of gene arrays in brain tissue indicated that PON1 suppresses biological functions and pathways associated with oxidative stress, inflammation, vascular dysfunction, thrombosis, and fibrosis. PON1 enhances the cerebroprotective effects of HDL and is a potential candidate for acute stroke therapy.

BAK ameliorated cerebral infarction/ischemia-reperfusion injury by activating AMPK/Nrf2 to inhibit TXNIP/NLRP3/caspase-1 axis

BACKGROUND

Cerebral ischemia/reperfusion (I/R) injury is a serious vascular disease with extremely high mortality and disability rate. Bakuchiol (BAK) was found in leaves and seeds of Psoralea corylifolia Linn and has been shown to decrease inflammation and reduce oxidative stress, while the mechanism of BAK in ameliorating cerebral I/R injury remains unclear.

METHODS

Middle cerebral artery occlusion reperfusion (MACO/R) was used to establish mouse model. The protective effect of BAK in MCAO/R mices was detected by performing neurological deficit testing, TTC staining, and H&E staining. Oxygen/glucose deprivation and reperfusion (OGD/R) was used to stimulate SH-SY5Y cells in vitro. Protein expression was detected by western blotting, gene expression was detected by quantitative real-time polymerase chain reaction and apoptosis was detected by immunofluorescence.

RESULTS

Our study indicated that BAK protected ischemia-reperfusion injury in MACO/R mice, and upregulated superoxide dismutase (SOD) and the catalase (CAT) enzyme activity. BAK also inhibited the expression of TNF-α, IL-1β, IL-6, and IL-18 and suppressed apoptosis and pyroptosis both in MACO/R mice and in OGD/R SH-SY5Y cells. Further results showed that BAK could suppress TXNIP, ASC, NLRP3, and caspase-1 mRNA levels to reverse assembly of inflammasome. And BAK could also upregulate the expression of phosphorylated AMP-activated protein kinase (AMPK) and nuclear factor erythroid 2-related factor (Nrf2). In addition, Nrf2 inhibitor ML385 reversed the BAK induced reduction of TXNIP, ASC, NLRP3, and the AMPK inhibitor also abolished BAK' the effect on the regulation of Nrf2, TXNIP, ASC, NLRP3, caspase-1, and pro-inflammatory cytokines. In conclusion, BAK, found in leaves and seeds of Psoralea corylifolia Linn, could ameliorated cerebral I/R injury through activating AMPK/Nrf2 to inhibit NLRP3 inflammasome, which might present new therapeutic strategy for cerebral I/R injury.

Predictive Value of Epicardial Adipose Tissue for Hemorrhagic Transformation and Functional Outcomes in Acute Ischemic Stroke Patients Undergoing Intravenous Thrombolysis Therapy

Purpose

Hemorrhagic transformation (HT) is a severe complication in patients with acute ischemic stroke (AIS) undergoing intravenous thrombolysis therapy (IVT). Epicardial adipose tissue (EAT) contributes to the development of AIS and the disruption of the blood-brain barrier. This study aims to investigate the relationship between EAT and the risk of HT, as well as functional outcomes, in AIS patients treated with IVT.

Patients and Methods

230 AIS patients were included. Epicardial adipose tissue volume (EATV) and EAT attenuation were measured from chest CT scans. Follow-up cranial CT or magnetic resonance imaging (MRI) assessed HT occurrence. Patients were stratified into groups based on the presence of HT or parenchymal hematoma (PH), and their 90-day functional outcomes (evaluated by the modified Rankin Scale).

Results

HT occurred in 52 (22.61%) patients, including 28 (12.17%) patients with PH, 85 (37.00%) patients had poor 90-day functional prognosis. Compared to the first quartile of EATV, the third quartile (OR 9.254, 95% CI 1.533-55.853) and the fourth quartile (OR 11.117, 95% CI 1.925-64.211) of EATV were independent predictors of HT; and EATV as a continuous variable (OR 1.022, 95% CI 1.005-1.040) was an independent risk factor for PH. Higher EAT attenuation was independently associated with poor prognosis (OR 1.170, 95% CI 1.056-1.297). The area under curve for predicting HT, PH and 90-day poor functional outcome was 0.705 (95% CI 0.632-0.778), 0.693 (95% CI 0.597-0.789), and 0.720 (95% CI 0.653-0.787).

Conclusion

The study demonstrates that EAT is associated with HT and poor 90-day outcomes in AIS patients undergoing IVT.

Aquaporin proteins: A promising frontier for therapeutic intervention in cerebral ischemic injury

Cerebral ischemic injury is characterized by reduced blood flow to the brain, remains a significant cause of morbidity and mortality worldwide. Despite improvements in therapeutic approaches, there is an urgent need to identify new targets to lessen the effects of ischemic stroke. Aquaporins, a family of water channel proteins, have recently come to light as promising candidates for therapeutic intervention in cerebral ischemic injury. There are 13 aquaporins identified, and AQP4 has been thoroughly involved with cerebral ischemia as it has been reported that modulation of AQP4 activity can offers a possible pathway for therapeutic intervention along with their role in pH, osmosis, ions, and the blood-brain barrier (BBB) as possible therapeutic targets for cerebral ischemia injury. The molecular pathways which can interacts with particular cellular pathways, participation in neuroinflammation, and possible interaction with additional proteins thought to be involved in the etiology of a stroke. Understanding these pathways offers crucial information on the diverse role of AQPs in cerebral ischemia, paving the door for the development of focused/targeted therapeutics.

Role of the transcription factor NRF2 in maintaining the integrity of the Blood-Brain Barrier

BACKGROUND

The Blood-Brain Barrier (BBB) is a complex and dynamic interface that regulates the exchange of molecules and cells between the blood and the central nervous system. It undergoes structural and functional throughout oxidative stress and inflammation, which may compromise its integrity and contribute to the pathogenesis of neurodegenerative diseases.

MAIN BODY

Maintaining BBB integrity is of utmost importance in preventing a wide range of neurological disorders. NRF2 is the main transcription factor that regulates cellular redox balance and inflammation-related gene expression. It has also demonstrated a potential role in regulating tight junction integrity and contributing to the inhibition of ECM remodeling, by reducing the expression of several metalloprotease family members involved in maintaining BBB function. Overall, we review current insights on the role of NRF2 in addressing protection against the effects of BBB dysfunction, discuss its involvement in BBB maintenance in different neuropathological diseases, as well as, some of its potential activators that have been used in vitro and in vivo animal models for preventing barrier dysfunction.

CONCLUSIONS

Thus, emerging evidence suggests that upregulation of NRF2 and its target genes could suppress oxidative stress, and neuroinflammation, restore BBB integrity, and increase its protection.

The Quest for Eternal Youth: Hallmarks of Aging and Rejuvenating Therapeutic Strategies

The impressive achievements made in the last century in extending the lifespan have led to a significant growth rate of elderly individuals in populations across the world and an exponential increase in the incidence of age-related conditions such as cardiovascular diseases, diabetes mellitus type 2, and neurodegenerative diseases. To date, geroscientists have identified 12 hallmarks of aging (genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, impaired macroautophagy, mitochondrial dysfunction, impaired nutrient sensing, cellular senescence, stem cell exhaustion, defective intercellular communication, chronic inflammation, and gut dysbiosis), intricately linked among each other, which can be targeted with senolytic or senomorphic drugs, as well as with more aggressive approaches such as cell-based therapies. To date, side effects seriously limit the use of these drugs. However, since rejuvenation is a dream of mankind, future research is expected to improve the tolerability of the available drugs and highlight novel strategies. In the meantime, the medical community, healthcare providers, and society should decide when to start these treatments and how to tailor them individually.

NaturalEssential Oils: A Promising Therapy Way for Treating Ischemic Stroke

Stroke is an acute cerebrovascular disease with high morbidity, mortality, and disability, making it the second leading cause of death worldwide. Ischemic stroke (IS) accounts for the majority of strokes, and its pathogenesis is complex, often involving complications and sequelae. Currently, conventional clinical approaches are ineffective, with few drugs available for intravenous thrombolysis and mechanical thrombolysis limited by a short time window. With the poor efficacy of monotherapy, the search for new complementary or alternative therapies has become the focus of researchers. In traditional medicine, Chinese aromatherapy has a long history of using aromatic medicines to treat IS. Natural essential oils (EOs), as the main pharmacological substances in aromatic drugs, are composed of different ratios of active metabolites with multi-targets and multi-components, which makes EOs have a wide range of pharmacological effects. Modern studies have also shown that EOs extracts and isolated monomers are beneficial for pathologically complex CIS. Therefore, this paper summarizes the EOs and monomers obtained from EOs that can prevent and treat IS in the last 20 years, and finds that EOs exert their anti-CIS effects mainly through anti-oxidative stress, anti-inflammation, anti-apoptosis, and inhibition of excitotoxicity. The amelioration of IS complications by natural EOs and their active monomer components for the treatment of IS are further discussed.

Keap1-independent GSK-3β/Nrf2 signaling mediates electroacupuncture inhibition of oxidative stress to induce cerebral ischemia-reperfusion tolerance

PURPOSE

Cerebral ischemia-reperfusion (CIR) injury is a devastating consequence of stroke characterized by oxidative stress-induced neuronal damage. Electroacupuncture (EA) has emerged as a potential therapeutic intervention for ischemic stroke, but its underlying mechanisms remain incompletely understood. This study aimed to elucidate whether EA exerts anti-oxidative stress effects against CIR injury by modulating the GSK-3β/Nrf2 pathway.

METHODS

CIR mouse models were established using the suture-occluded method and underwent EA pretreatment. Cognitive and neurologic function, cerebral infarct volume, and neuronal damage were assessed in mice. Oxidative stress levels and the expression of components of the GSK-3β/Nrf2 pathway in the cerebral cortex were measured. The regulatory effect of GSK-3β on Nrf2 and its role in electroacupuncture to alleviate oxygen-glucose deprivation/reoxygenation (OGD/R)-induced neuronal injury were investigated by modulating GSK-3β expression in HT22 hippocampal neuronal cells and electroacupuncture serum intervention. Ultimately, Nrf2 knockout mice, GSK-3β knockout mice, and wild-type mice treated with TBHQ (an Nrf2 activator) were utilized for further validation.

RESULTS

EA pretreatment improved cognitive impairment and neuronal damage induced by CIR injury. Mechanistically, EA inhibited oxidative stress in the cerebral cortex, manifested by reduced levels of reactive oxygen species and malondialdehyde, along with increased superoxide dismutase activity. Furthermore, EA upregulated the expression of Nrf2 and its downstream antioxidant enzymes HO-1 and NQO1, while Keap1 expression remained unaffected. In vitro, GSK-3β overexpression inhibited the protective effects of EA serum on OGD/R-induced neuronal damage. In vivo, knockout of either Nrf2 or Gsk-3β genes abolished the neuroprotective effects of EA, and TBHQ exerted effects similar to EA, confirming the significant role of GSK-3β/Nrf2 in mediating EA antioxidative effects.

CONCLUSION

EA exerts antioxidative stress effects against CIR injury by activating the GSK-3β/Nrf2 signaling pathway, independent of Keap1 regulation.

Unlocking the possibilities of therapeutic potential of silymarin and silibinin against neurodegenerative Diseases-A mechanistic overview

Silymarin, a bioflavonoid derived from the Silybum marianum plant, was discovered in 1960. It contains C25 and has been extensively used as a therapeutic agent against liver-related diseases caused by alcohol addiction, acute viral hepatitis, and toxins-inducing liver failure. Its efficacy stems from its role as a potent anti-oxidant and scavenger of free radicals, employed through various mechanisms. Additionally, silymarin or silybin possesses immunomodulatory characteristics, impacting immune-enhancing and immune-suppressive functions. Recently, silymarin has been recognized as a potential neuroprotective therapy for various neurological conditions, including Parkinson's and Alzheimer's diseases, along with conditions related to cerebral ischemia. Its hepatoprotective qualities, primarily due to its anti-oxidant and tissue-regenerating properties, are well-established. Silymarin also enhances health by modifying processes such as inflammation, β-amyloid accumulation, cellular estrogenic receptor mediation, and apoptotic machinery. While believed to reduce oxidative stress and support neuroprotective mechanisms, these effects represent just one aspect of the compound's multifaceted protective action. This review article further delves into the possibilities of potential therapeutic advancement of silymarin and silibinin for the management of neurodegenerative disorders via mechanics modules.

The role of oxidative stress in blood-brain barrier disruption during ischemic stroke: Antioxidants in clinical trials

Ischemic stroke is one of the leading causes of death and disability. Occlusion and reperfusion of cerebral blood vessels (i.e., ischemia/reperfusion (I/R) injury) generates reactive oxygen species (ROS) that contribute to brain cell death and dysfunction of the blood-brain barrier (BBB) via oxidative stress. BBB disruption influences the pathogenesis of ischemic stroke by contributing to cerebral edema, hemorrhagic transformation, and extravasation of circulating neurotoxic proteins. An improved understanding of mechanisms for ROS-associated alterations in BBB function during ischemia/reperfusion (I/R) injury can lead to improved treatment paradigms for ischemic stroke. Unfortunately, progress in developing ROS targeted therapeutics that are effective for stroke treatment has been slow. Here, we review how ROS are produced in response to I/R injury, their effects on BBB integrity (i.e., tight junction protein complexes, transporters), and the utilization of antioxidant treatments in ischemic stroke clinical trials. Overall, knowledge in this area provides a strong translational framework for discovery of novel drugs for stroke and/or improved strategies to mitigate I/R injury in stroke patients.

Application of Nanozymes and its Progress in the Treatment of Ischemic Stroke

Nanozymes are a new kind of material which has been applied since the beginning of this century, and its birth has promoted the development of chemistry, materials science, and biology. Nanozymes can be used as a substitute for natural enzyme and has a wide range of applications; therefore, it has attracted extensive attention from all sectors of the community, and the number of studies has constantly increasing. In this paper, we introduced the outstanding achievements in the field of nanozymes in recent years from the main function, the construction of nanozyme-based biosensors, and the treatment of ischemic stroke, and we also illustrated the internal mechanism and the catalytic principle. In the end, the obstacles and challenges in the future development of nanozymes were proposed.

Inflammaging and Brain Aging

Progress made by the medical community in increasing lifespans comes with the costs of increasing the incidence and prevalence of age-related diseases, neurodegenerative ones included. Aging is associated with a series of morphological changes at the tissue and cellular levels in the brain, as well as impairments in signaling pathways and gene transcription, which lead to synaptic dysfunction and cognitive decline. Although we are not able to pinpoint the exact differences between healthy aging and neurodegeneration, research increasingly highlights the involvement of neuroinflammation and chronic systemic inflammation (inflammaging) in the development of age-associated impairments via a series of pathogenic cascades, triggered by dysfunctions of the circadian clock, gut dysbiosis, immunosenescence, or impaired cholinergic signaling. In addition, gender differences in the susceptibility and course of neurodegeneration that appear to be mediated by glial cells emphasize the need for future research in this area and an individualized therapeutic approach. Although rejuvenation research is still in its very early infancy, accumulated knowledge on the various signaling pathways involved in promoting cellular senescence opens the perspective of interfering with these pathways and preventing or delaying senescence.

Blood-Brain Barrier Disruption and Imaging Assessment in Stroke

Disruption of the blood-brain barrier (BBB) is an important pathological hallmark of ischemic stroke. Blood-brain barrier disruption (BBBD) is a consequence of ischemia and may also exacerbate damage to brain parenchyma. Therefore, maintaining BBB integrity is critical for the central nervous system (CNS) homeostasis. This review offers a concise overview of BBB structure and function, along with the mechanisms underlying its impairment following a stroke. In addition, we review the recent imaging techniques employed to study blood-brain barrier permeability (BBBP) in the context of ischemic brain injury with the goal of providing imaging guidance for stroke diagnosis and treatment from the perspective of the BBBD. This knowledge is vital for developing strategies to safeguard the BBB during cerebral ischemia.

Ischemic Microenvironment-Targeted Bioinspired Lipoprotein Sequentially Penetrates Cerebral Ischemic Lesions to Rescue Ischemic Stroke

Reperfusion injury represents a significant impediment to recovery after recanalization in an ischemic stroke and can be alleviated by neuroprotectants. However, inadequate drug delivery to ischemic lesions impairs the therapeutic effects of neuroprotectants. To address this issue, an ischemic microenvironment-targeted bioinspired lipoprotein system encapsulating lipoic acid (LA@PHDL) is herein designed to sequentially penetrate ischemic lesions and be readily taken up by neurons and microglia. In transient middle cerebral artery occlusion (tMCAO) mouse models, LA@PHDL accumulates rapidly and preferentially in the ischemic brain, with a 2.29-fold higher than the nontargeted nanoplatform in the early stage. Furthermore, LA@PHDL effectively restores neurological function, reduces infarct volume to 17.70%, prevents brain cell necrosis and apoptosis, and attenuates inflammation in tMCAO mouse models. This design presents new opportunities for delivering neuroprotectants to cerebral ischemic lesions to improve the outcome of an ischemic stroke.

Rooted in therapeutics: comprehensive analyses of Cannabis sativa root extracts reveals potent antioxidant, anti-inflammatory, and bactericidal properties

Following the legalization of recreational Cannabis in Canada in 2018, the associated waste, including Cannabis roots, has significantly increased. Cannabis roots, comprising 30%-50% of the total plant, are often discarded despite their historical use in Ayurvedic medicine for treating inflammatory and infectious disorders. This study evaluates the phytochemical and therapeutic properties of Cannabis root extracts from a high tetrahydrocannabinolic acid, low cannabidiolic acid cultivar (variety Alien Gorilla Glue). We performed ultra high-performance liquid chromatography coupled with mass spectrometry (UPLC-QTOF-MS) to identify the chemical components of the Cannabis roots. Extracts using water, ethanol and acid-base solvents were tested for antioxidant activity through free radical scavenging, metal chelation, and lipoperoxidation inhibition assays. Mitochondrial membrane protection was assessed using flow cytometry with the MitoPerOx probe in THP-1 monocytic leukemia cells. Anti-inflammatory potential was evaluated by measuring interleukin-6 levels in lipopolysaccharide-stimulated THP-1 cells. Bactericidal/fungicidal efficacy against Escherichia coli, Staphylococcus aureus, and Candida albicans was determined using the p-iodonitrophenyltetrazolium assay. Additionally, we investigated the anticholinesterase activity of Cannabis root extracts, given the potential role of plant alkaloids in inhibiting cholinesterase, an enzyme targeted in Alzheimer's disease treatments. UPLC-QTOF-MS analysis suggested the presence of several phenolic compounds, cannabinoids, terpenoids, amino acids, and nitrogen-containing compounds. Our results indicated significant antioxidant, bactericidal, and anticholinesterase properties of Cannabis root extracts from both soil and hydroponic cultivation. Extracts showed strong antioxidant activity across multiple assays, protected mitochondrial membrane in THP-1 cells, and exhibited anti-inflammatory and bactericidal/fungicidal efficacy. Notably, soil-cultivated roots displayed superior anti-inflammatory effects. These findings demonstrate the remarkable antioxidant, anti-inflammatory, and anti-microbial activities of Cannabis roots, supporting their traditional uses and challenging their perception as mere waste. This study highlights the therapeutic potential of Cannabis roots extracts and suggests avenues for further research and application.

Unveiling citicoline's mechanisms and clinical relevance in the treatment of neuroinflammatory disorders

Citicoline, a compound produced naturally in small amounts in the human body, assumes a pivotal role in phosphatidylcholine synthesis, a dynamic constituent of membranes of neurons. Across diverse models of brain injury and neurodegeneration, citicoline has demonstrated its potential through neuroprotective and anti-inflammatory effects. This review aims to elucidate citicoline's anti-inflammatory mechanism and its clinical implications in conditions such as ischemic stroke, head trauma, glaucoma, and age-associated memory impairment. Citicoline's anti-inflammatory prowess is rooted in its ability to stabilize cellular membranes, thereby curbing the excessive release of glutamate-a pro-inflammatory neurotransmitter. Moreover, it actively diminishes free radicals and inflammatory cytokines productions, which could otherwise harm neurons and incite neuroinflammation. It also exhibits the potential to modulate microglia activity, the brain's resident immune cells, and hinder the activation of NF-κB, a transcription factor governing inflammatory genes. Clinical trials have subjected citicoline to rigorous scrutiny in patients grappling with acute ischemic stroke, head trauma, glaucoma, and age-related memory impairment. While findings from these trials are mixed, numerous studies suggest that citicoline could confer improvements in neurological function, disability reduction, expedited recovery, and cognitive decline prevention within these cohorts. Additionally, citicoline boasts a favorable safety profile and high tolerability. In summary, citicoline stands as a promising agent, wielding both neuroprotective and anti-inflammatory potential across a spectrum of neurological conditions. However, further research is imperative to delineate the optimal dosage, treatment duration, and underlying mechanisms. Moreover, identifying specific patient subgroups most likely to reap the benefits of citicoline as a new therapy remains a critical avenue for exploration.

Treatment of Acute and Long-COVID, Diabetes, Myocardial Infarction, and Alzheimer's Disease: The Potential Role of a Novel Nano-Compound-The Transdermal Glutathione-Cyclodextrin Complex

Oxidative stress (OS) occurs from excessive reactive oxygen species or a deficiency of antioxidants-primarily endogenous glutathione (GSH). There are many illnesses, from acute and post-COVID-19, diabetes, myocardial infarction to Alzheimer's disease, that are associated with OS. These dissimilar illnesses are, in order, viral infections, metabolic disorders, ischemic events, and neurodegenerative disorders. Evidence is presented that in many illnesses, (1) OS is an early initiator and significant promotor of their progressive pathophysiologic processes, (2) early reduction of OS may prevent later serious and irreversible complications, (3) GSH deficiency is associated with OS, (4) GSH can likely reduce OS and restore adaptive physiology, (5) effective administration of GSH can be accomplished with a novel nano-product, the GSH/cyclodextrin (GC) complex. OS is an overlooked pathological process of many illnesses. Significantly, with the GSH/cyclodextrin (GC) complex, therapeutic administration of GSH is now available to reduce OS. Finally, rigorous prospective studies are needed to confirm the efficacy of this therapeutic approach.

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.

Microcirculatory Impairment and Cerebral Injury in Hydrocephalus and the Effects of Cerebrospinal Fluid Diversion

BACKGROUND AND OBJECTIVES

Hydrocephalus is characterized by progressive enlargement of cerebral ventricles, resulting in impaired microvasculature and cerebral hypoperfusion. This study aimed to demonstrate the microvascular changes in hydrocephalic rats and the effects of cerebrospinal fluid (CSF) release on cerebral blood flow (CBF).

METHODS

On postnatal day 21 (P21), male Wistar rats were intracisternally injected with either a kaolin suspension or saline. On P47, Evan's ratio (ER) was measured using MRI. On P49, the arteriolar diameter and vascular density of the pia were quantified using a capillary video microscope. The CBF was measured using laser Doppler flowmetry. The expressions of NeuN and glial fibrillary acidic protein determined by immunochemical staining were correlated with the ER. The CBF and rotarod test performance were recorded before and after CSF release. The expressions of 4-hydroxynonenal (4-HNE) and c-caspase-3 were studied on P56.

RESULTS

Ventriculomegaly was induced to varying degrees, resulting in the stretching and abnormal narrowing of pial arterioles, which regressed with increasing ER. Quantitative analysis revealed significant decreases in the arteriolar diameter and vascular density in the hydrocephalic group compared with those in the control group. In addition, the CBF in the hydrocephalic group decreased to 30%-50% of that in the control group. In hydrocephalus, the neurons appear distorted, and the expression of 4-HNE and reactive astrogliosis increase in the cortex. After CSF was released, improvements in the CBF and rotarod test performance were inversely associated with the ER. In addition, the levels of 4-HNE and c-caspase-3 were further elevated.

CONCLUSION

Rapid ventricular dilatation is associated with severe microvascular distortion, vascular regression, cortical hypoperfusion, and cellular changes that impair the recovery of CBF and motor function after CSF release. Moreover, CSF release may induce reperfusion injury. This pathophysiology should be taken into account when treating hydrocephalus.

Research progress and challenges of stem cell therapy for ischemic stroke

Ischemic stroke is a significant global cause of death and disability. Currently, treatment options for acute ischemic stroke are limited to intravenous thrombolysis and mechanical recanalization. Therefore, novel neuroprotective strategies are imperative. Stem cell transplantation possesses the capabilities of differentiation, proliferation, neuronal replacement, nerve pathway reconstruction, secretion of nerve growth factors, and enhancement of the microenvironment; thus, it is a potential therapeutic approach for ischemic stroke. In addition, the immunomodulatory function of stem cells and the combined treatment of stem cells and exosomes exhibit a favorable protective effect on brain injury and neurological dysfunction following stroke. Meanwhile, the theory of microbiota-gut-brain axis provides us with a novel perspective for comprehending and managing neurological diseases. Lastly, stem cell transplantation has demonstrated promising outcomes not only in treating ischemic stroke but also in dealing with other neurological disorders, such as brain tumors. Furthermore, challenges related to the tissue source, delivery method, immune response, and timing of transplantation still need to be addressed to optimize the treatment.

Molecular Pathogenesis of Ischemic and Hemorrhagic Strokes: Background and Therapeutic Approaches

Stroke represents one of the neurological diseases most responsible for death and permanent disability in the world. Different factors, such as thrombus, emboli and atherosclerosis, take part in the intricate pathophysiology of stroke. Comprehending the molecular processes involved in this mechanism is crucial to developing new, specific and efficient treatments. Some common mechanisms are excitotoxicity and calcium overload, oxidative stress and neuroinflammation. Furthermore, non-coding RNAs (ncRNAs) are critical in pathophysiology and recovery after cerebral ischemia. ncRNAs, particularly microRNAs, and long non-coding RNAs (lncRNAs) are essential for angiogenesis and neuroprotection, and they have been suggested to be therapeutic, diagnostic and prognostic tools in cerebrovascular diseases, including stroke. This review summarizes the intricate molecular mechanisms underlying ischemic and hemorrhagic stroke and delves into the function of miRNAs in the development of brain damage. Furthermore, we will analyze new perspectives on treatment based on molecular mechanisms in addition to traditional stroke therapies.

In vivo protective effects of 6‑gingerol in cerebral ischemia involve preservation of antioxidant defenses and activation of anti‑apoptotic pathways

Stroke is an important medical problem in developing countries, characterized by a sudden disruption of blood supply to the brain, either through occlusion or hemorrhage. It is a major cause of neurological impairment, resulting in high medical costs. The present study examined the effect of 6-gingerol on morphological changes, antioxidant defenses, and the anti-apoptotic factors p38 mitogen-activated protein kinase (MAPK) and mitofusin (Mfn)2, in a rat model of focal cerebral ischemia. A total of 60 healthy male Wistar rats were randomly allocated into six groups: Control, right middle cerebral artery occlusion (Rt.MCAO) + vehicle, Rt.MCAO + piracetam, and Rt.MCAO + 6-Gin 5, 10 and 20 mg/kg BW groups. The results indicated that 6-gingerol treatment for a duration of 7 days reverses morphological alterations, enhances catalase and glutathione peroxidase activities, reduces Bax, caspase-3 and MAPK expression, and increases Bcl-xL and Mfn2 expression in the cortex and hippocampus. In conclusion, 6-gingerol demonstrated significant in vivo effectiveness in mitigating pathological changes induced by cerebral ischemia. This beneficial effect is attributed, at least in part, to preservation of antioxidant defenses and activation of anti-apoptotic pathways.

A novel HDAC8 inhibitor H7E exerts retinoprotective effects against glaucomatous injury via ameliorating aberrant Müller glia activation and oxidative stress

Glaucoma is considered a neurodegenerative disease characterized by progressive visual field defects that may lead to blindness. Although controlling intraocular pressure (IOP) is the mainstay of glaucoma treatment, some glaucoma patients have unmet needs due to unclear pathogenic mechanisms. Recently, there has been growing evidence that neuroinflammation is a potential target for the development of novel antiglaucoma agents. In this study, we investigated the protective effects and cellular mechanisms of H7E, a novel small molecule inhibits HDAC8, using in vitro and in vivo glaucoma-like models. Importantly, H7E mitigated extracellular MMP-9 activity and MCP-1 levels in glutamate- or S100B-stimulated reactive Müller glia. In addition, H7E inhibited the upregulation of inflammation- and proliferation-related signaling pathways, particularly the ERK and JNK MAPK pathways. Under conditions of oxidative damage, H7E prevents retinal cell death and reduces extracellular glutamate released from stressed Müller glia. In a mouse model of NMDA-induced retinal degeneration, H7E alleviated functional and structural defects within the inner retina as assessed by electroretinography and optical coherence tomography. Our results demonstrated that the newly identified compound H7E protects against glaucoma damage by specifically targeting HDAC8 activity in the retina. This protective effect is attributed to the inhibition of Müller glial activation and the prevention of retinal cell death caused by oxidative stress.

Overnutrition and Lipotoxicity: Impaired Efferocytosis and Chronic Inflammation as Precursors to Multifaceted Disease Pathogenesis

Overnutrition, driven by the consumption of high-fat, high-sugar diets, has reached epidemic proportions and poses a significant global health challenge. Prolonged overnutrition leads to the deposition of excessive lipids in adipose and non-adipose tissues, a condition known as lipotoxicity. The intricate interplay between overnutrition-induced lipotoxicity and the immune system plays a pivotal role in the pathogenesis of various diseases. This review aims to elucidate the consequences of impaired efferocytosis, caused by lipotoxicity-poisoned macrophages, leading to chronic inflammation and the subsequent development of severe infectious diseases, autoimmunity, and cancer, as well as chronic pulmonary and cardiovascular diseases. Chronic overnutrition promotes adipose tissue expansion which induces cellular stress and inflammatory responses, contributing to insulin resistance, dyslipidemia, and metabolic syndrome. Moreover, sustained exposure to lipotoxicity impairs the efferocytic capacity of macrophages, compromising their ability to efficiently engulf and remove dead cells. The unresolved chronic inflammation perpetuates a pro-inflammatory microenvironment, exacerbating tissue damage and promoting the development of various diseases. The interaction between overnutrition, lipotoxicity, and impaired efferocytosis highlights a critical pathway through which chronic inflammation emerges, facilitating the development of severe infectious diseases, autoimmunity, cancer, and chronic pulmonary and cardiovascular diseases. Understanding these intricate connections sheds light on potential therapeutic avenues to mitigate the detrimental effects of overnutrition and lipotoxicity on immune function and tissue homeostasis, thereby paving the way for novel interventions aimed at reducing the burden of these multifaceted diseases on global health.

Neuroprotective and Anti-Inflammatory Activities of Hybrid Small-Molecule SA-10 in Ischemia/Reperfusion-Induced Retinal Neuronal Injury Models

Embolism, hyperglycemia, high intraocular pressure-induced increased reactive oxygen species (ROS) production, and microglial activation result in endothelial/retinal ganglion cell death. Here, we conducted in vitro and in vivo ischemia/reperfusion (I/R) efficacy studies of a hybrid antioxidant-nitric oxide donor small molecule, SA-10, to assess its therapeutic potential for ocular stroke.

METHODS

To induce I/R injury and inflammation, we subjected R28 and primary microglial cells to oxygen glucose deprivation (OGD) for 6 h in vitro or treated these cells with a cocktail of TNF-α, IL-1β and IFN-γ for 1 h, followed by the addition of SA-10 (10 µM). Inhibition of microglial activation, ROS scavenging, cytoprotective and anti-inflammatory activities were measured. In vivo I/R-injured mouse retinas were treated with either PBS or SA-10 (2%) intravitreally, and pattern electroretinogram (ERG), spectral-domain optical coherence tomography, flash ERG and retinal immunocytochemistry were performed.

RESULTS

SA-10 significantly inhibited microglial activation and inflammation in vitro. Compared to the control, the compound SA-10 significantly attenuated cell death in both microglia (43% vs. 13%) and R28 cells (52% vs. 17%), decreased ROS (38% vs. 68%) production in retinal microglia cells, preserved neural retinal function and increased SOD1 in mouse eyes.

CONCLUSION

SA-10 is protective to retinal neurons by decreasing oxidative stress and inflammatory cytokines.

Research hotspots and frontiers of preconditioning in cerebral ischemia: A bibliometric analysis

Background

Preconditioning is a promising strategy against ischemic brain injury, and numerous studies in vitro and in vivo have demonstrated its neuroprotective effects. However, at present there is no bibliometric analysis of preconditioning in cerebral ischemia. Therefore, a comprehensive overview of the current status, hot spots, and emerging trends in this research field is necessary.

Materials and methods

Studies on preconditioning in cerebral ischemia from January 1999-December 2022 were retrieved from the Web of Science Core Collection (WOSCC) database. CiteSpace was used for data mining and visual analysis.

Results

A total of 1738 papers on preconditioning in cerebral ischemia were included in the study. The annual publications showed an upwards and then downwards trend but currently remain high in terms of annual publications. The US was the leading country, followed by China, the most active country in recent years. Capital Medical University published the largest number of articles. Perez-Pinzon, Miguel A contributed the most publications, while KITAGAWA K was the most cited author. The focus of the study covered three areas: (1) relevant diseases and experimental models, (2) types of preconditioning and stimuli, and (3) mechanisms of ischemic tolerance. Remote ischemic preconditioning, preconditioning of mesenchymal stem cells (MSCs), and inflammation are the frontiers of research in this field.

Conclusion

Our study provides a visual and scientific overview of research on preconditioning in cerebral ischemia, providing valuable information and new directions for researchers.

Vialinin A alleviates oxidative stress and neuronal injuries after ischaemic stroke by accelerating Keap1 degradation through inhibiting USP4-mediated deubiquitination

BACKGROUND

Oxidative stress is known as a hallmark of cerebral ischaemia‒reperfusion injury and it exacerbates the pathologic progression of ischaemic brain damage. Vialinin A, derived from a Chinese edible mushroom, possesses multiple pharmacological activities in cancer, Kawasaki disease, asthma and pathological scarring. Notably, vialinin A is an inhibitor of ubiquitin-specific peptidase 4 (USP4) that shows anti-inflammatory and antioxidative properties. However, the precise effect of vialinin A in ischaemic stroke, as well as its underlying mechanisms, remains largely unexplored.

PURPOSE

The present research focuses on the impacts of vialinin A on oxidative stress and explores the underlying mechanisms involved while also examining its potentiality as a therapeutic candidate for ischaemic stroke.

METHODS

Mouse ischaemic stroke was conducted by MCAO surgery. Vialinin A was administered via lateral ventricular injection at a dose of 2 mg/kg after reperfusion. Subsequent experiments were meticulously conducted at the appropriate time points. Stroke outcomes were evaluated by TTC staining, neurological score, Nissl staining and behavioural analysis. Co-IP assays were operated to examine the protein-protein interactions. Immunoblot analysis, qRT-PCR, and luciferase reporter assays were conducted to further investigate its underlying mechanisms.

RESULTS

In this study, we initially showed that administration of vialinin A alleviated cerebral ischaemia‒reperfusion injury-induced neurological deficits and neuronal apoptosis. Furthermore, vialinin A, which is an antioxidant, reduced oxidative stress injury, promoted the activation of the Keap1-Nrf2-ARE signaling pathway and increased the protein degradation of Keap1. The substantial neuroprotective effects of vialinin A against ischaemic stroke were compromised by the overexpression of USP4. Mechanistically, vialinin A inhibited the deubiquitinating enzymatic activity of USP4, leading to enhanced ubiquitination of Keap1 and subsequently promoting its degradation. This cascade caused the activation of Nrf2-dependent antioxidant response, culminating in a reduction of neuronal apoptosis and the amelioration of neurological dysfunction following ischaemic stroke.

CONCLUSIONS

This study demonstrates that inhibition of USP4 to activate Keap1-Nrf2-ARE signaling pathway may represent a mechanism by which vialinin A conferred protection against cerebral ischaemia‒reperfusion injury and sheds light on its promising prospects as a therapeutic intervention for ischaemic stroke.

A Comprehensive Review on the Significance of Cysteine in Various Metabolic Disorders; Particularly CVD, Diabetes, Renal Dysfunction, and Ischemic Stroke

Metabolic disorders have long been a challenge for medical professionals and are a leading cause of mortality in adults. Diabetes, cardiovascular disorders (CVD), renal dysfunction, and ischemic stroke are the most prevalent ailments contributing to a high mortality rate worldwide. Reactive oxygen species are one of the leading factors that act as a fundamental root cause of metabolic syndrome. All of these disorders have their respective treatments, which, to some degree, sabotage the pathological worsening of the disease and an inevitable death. However, they pose a perilous health hazard to humankind. Cysteine, a functional amino acid shows promise for the prevention and treatment of metabolic disorders, such as CVD, Diabetes mellitus, renal dysfunction, and ischemic stroke. In this review, we explored whether cysteine can eradicate reactive oxygen species and subsequently prevent and treat these diseases.

[Efficacy of Mexidol in combination with cerebral revascularization in the treatment of ischemic stroke]

Stroke is an acute life-threatening condition; its outcome is determined by the degree of damage to brain tissue, the quality and speed of medical care in the first minutes and hours after its occurrence. The main mechanism of brain tissue damage during both ischemia and reperfusion is oxidative stress. The review covers adverse influence oxidative stress at the cerebral ischemia and reperfusion periodes of ischemic stroke. The results of preclinical studies demonstrating the ability of Mexidol to neutralize the effects of free radicals and activate antioxidant protection are presented. Data from clinical studies of the use of Mexidol in combination with thrombolysis in patients with ischemic stroke are reviewed.

The Multitarget Action of Vitamins in the Ischemic Stroke

A stroke, also known as a cerebral hemorrhage, occurs when there is an interruption in the blood supply to a part of the brain, resulting in damage to brain cells. This issue is one of the leading causes of death in developed countries, currently killing about 5 million people annually. Individuals who survive ischemic stroke often face serious vision problems, paralysis, dementia, and other sequelae. The numerous efforts to prevent and/or treat stroke sequelae seem insufficient, which is concerning given the increasing global elderly population and the well-known association between aging and stroke risk. In this review, we aim to present and discuss the importance of vitamins in stroke prevention and/or incidence. Vitamins from diet or dietary supplements influence the body at various levels; they are a relevant factor but are reported only in isolated articles. This review reports and updates the multitarget role of vitamins involved in reducing stroke risk.

Blood-brain barrier permeability in the ischemic stroke: An update

Stroke is the second leading cause of death globally and the major cause of long-term disability. Among the types of strokes, ischemic stroke, which occurs due to obstruction of blood vessels responsible for cerebral irrigation, is considered the most prevalent, accounting for approximately 86 % of all stroke cases. This interruption of blood supply leads to a critical pathophysiological mechanism, including oxidative stress and neuroinflammation which are responsible for structural alterations of the blood-brain barrier (BBB). The increased BBB permeability associated with cerebral ischemia-reperfusion may contribute to a worse outcome after stroke. Thus, this narrative review aims to update the pathophysiological mechanisms involved in the increase in BBB permeability and to list the possible therapeutic strategies.

Hemorrhagic Coagulation Disorders and Ischemic Stroke: How to Reconcile Both?

Coagulation and fibrinolytic system disorders are conditions in which the blood's ability to clot is impaired, resulting in an increased risk of thrombosis or bleeding. Although these disorders are the expression of two opposing tendencies, they can often be associated with or be a consequence of each other, contributing to making the prognosis of acute cerebrovascular events more difficult. It is important to recognize those conditions that are characterized by dual alterations in the coagulation and fibrinolytic systems to reduce the prognostic impact of clinical conditions with difficult treatment and often unfortunate outcomes. Management of these individuals can be challenging, as clinicians must balance the need to prevent bleeding episodes with the potential risk of clot formation. Treatment decisions should be made on an individual basis, considering the specific bleeding disorder, its severity, and the patient's general medical condition. This review aims to deal with all those forms in which coagulation and fibrinolysis represent two sides of the same media in the correct management of patients with acute neurological syndrome. Precision medicine, personalized treatment, advanced anticoagulant strategies, and innovations in bleeding control represent future directions in the management of these complex pathologies in which stroke can be the evolution of two different acute events or be the first manifestation of an occult or unknown underlying pathology.

The Impact of Cerebral Ischemia on Antioxidant Enzymes Activity and Neuronal Damage in the Hippocampus

Cerebral ischemia and subsequent reperfusion, leading to reduced blood supply to specific brain areas, remain significant contributors to neurological damage, disability, and mortality. Among the vulnerable regions, the subcortical areas, including the hippocampus, are particularly susceptible to ischemia-induced injuries, with the extent of damage influenced by the different stages of ischemia. Neural tissue undergoes various changes and damage due to intricate biochemical reactions involving free radicals, oxidative stress, inflammatory responses, and glutamate toxicity. The consequences of these processes can result in irreversible harm. Notably, free radicals play a pivotal role in the neuropathological mechanisms following ischemia, contributing to oxidative stress. Therefore, the function of antioxidant enzymes after ischemia becomes crucial in preventing hippocampal damage caused by oxidative stress. This study explores hippocampal neuronal damage and enzymatic antioxidant activity during ischemia and reperfusion's early and late stages.

Signaling pathways in brain ischemia: Mechanisms and therapeutic implications

Ischemic stroke occurs when the arteries supplying blood to the brain are narrowed or blocked, inducing damage to brain tissue due to a lack of blood supply. One effective way to reduce brain damage and alleviate symptoms is to reopen blocked blood vessels in a timely manner and reduce neuronal damage. To achieve this, researchers have focused on identifying key cellular signaling pathways that can be targeted with drugs. These pathways include oxidative/nitrosative stress, excitatory amino acids and their receptors, inflammatory signaling molecules, metabolic pathways, ion channels, and other molecular events involved in stroke pathology. However, evidence suggests that solely focusing on protecting neurons may not yield satisfactory clinical results. Instead, researchers should consider the multifactorial and complex mechanisms underlying stroke pathology, including the interactions between different components of the neurovascular unit. Such an approach is more representative of the actual pathological process observed in clinical settings. This review summarizes recent research on the multiple molecular mechanisms and drug targets in ischemic stroke, as well as recent advances in novel therapeutic strategies. Finally, we discuss the challenges and future prospects of new strategies based on the biological characteristics of stroke.

Protein Carbonylation Contributes to Prothrombotic Fibrin Clot Phenotype in Acute Ischemic Stroke: Clinical Associations

BACKGROUND

Acute ischemic stroke (AIS) is associated with enhanced oxidative stress and unfavorably altered fibrin clot properties. We investigated determinants of plasma protein carbonylation (PC) in AIS, its impact on the prothrombotic state, and prognostic value during follow-up.

METHODS

We included 98 consecutive AIS patients aged 74±12 years (male:female ratio, 50:48 [51%:49%]) at the Neurology Center in Warsaw, Poland, between January and December 2014. As many as 74 (75.5%) patients underwent thrombolysis, and 24 were unsuitable for thrombolysis. We determined plasma PC, along with thrombin generation, fibrin clot permeability, and clot lysis time on admission, at 24 hours, and 3 months. Stroke severity was assessed using the National Institutes of Health Stroke Scale and stroke outcome with the modified Rankin Scale. Hemorrhagic transformation was assessed on the computed tomography scan within 48 hours from the symptom onset, while stroke-related mortality was evaluated at 3 months.

RESULTS

On admission, PC levels (median, 4.61 [3.81-5.70] nM/mg protein) were associated with the time since symptom onset (r=0.41; P<0.0001) and with the National Institutes of Health Stroke Scale score (P=0.36; P=0.0003). Higher PC levels on admission correlated with denser fibrin clot formation and prolonged clot lysis time but not with thrombin generation. In thrombolysed patients, lower PC levels were observed after 24 hours (-34%) and at 3 months (-23%; both P<0.001). PC levels at baseline and after 24 hours predicted the modified Rankin Scale score >2 at 3 months (OR, 1.90 [95% CI, 1.21-3.00]; OR, 2.19 [95% CI, 1.39-3.44], respectively). Higher PC at baseline predicted hemorrhagic transformation of stroke (OR, 1.95 [95% CI, 1.02-3.74]) and stroke-related mortality (OR, 2.02 [95% CI, 1.08-3.79]), while higher PC at 24 hours predicted solely stroke-related mortality (OR, 2.11 [95% CI, 1.28-3.46]).

CONCLUSIONS

Elevated plasma PC levels in patients with AIS, related to prothrombotic fibrin clot properties, are associated with stroke severity. Thrombolysis reduces the extent of PC. The current study suggests a prognostic value of PC in AIS.

Non-Excitatory Amino Acids, Melatonin, and Free Radicals: Examining the Role in Stroke and Aging

The aim of this review is to explore the relationship between melatonin, free radicals, and non-excitatory amino acids, and their role in stroke and aging. Melatonin has garnered significant attention in recent years due to its diverse physiological functions and potential therapeutic benefits by reducing oxidative stress, inflammation, and apoptosis. Melatonin has been found to mitigate ischemic brain damage caused by stroke. By scavenging free radicals and reducing oxidative damage, melatonin may help slow down the aging process and protect against age-related cognitive decline. Additionally, non-excitatory amino acids have been shown to possess neuroprotective properties, including antioxidant and anti-inflammatory in stroke and aging-related conditions. They can attenuate oxidative stress, modulate calcium homeostasis, and inhibit apoptosis, thereby safeguarding neurons against damage induced by stroke and aging processes. The intracellular accumulation of certain non-excitatory amino acids could promote harmful effects during hypoxia-ischemia episodes and thus, the blockade of the amino acid transporters involved in the process could be an alternative therapeutic strategy to reduce ischemic damage. On the other hand, the accumulation of free radicals, specifically mitochondrial reactive oxygen and nitrogen species, accelerates cellular senescence and contributes to age-related decline. Recent research suggests a complex interplay between melatonin, free radicals, and non-excitatory amino acids in stroke and aging. The neuroprotective actions of melatonin and non-excitatory amino acids converge on multiple pathways, including the regulation of calcium homeostasis, modulation of apoptosis, and reduction of inflammation. These mechanisms collectively contribute to the preservation of neuronal integrity and functions, making them promising targets for therapeutic interventions in stroke and age-related disorders.

Mitochondria in Huntington's disease: implications in pathogenesis and mitochondrial-targeted therapeutic strategies

Huntington's disease is a genetic disease caused by expanded CAG repeats on exon 1 of the huntingtin gene located on chromosome 4. Compelling evidence implicates impaired mitochondrial energetics, altered mitochondrial biogenesis and quality control, disturbed mitochondrial trafficking, oxidative stress and mitochondrial calcium dyshomeostasis in the pathogenesis of the disorder. Unfortunately, conventional mitochondrial-targeted molecules, such as cysteamine, creatine, coenzyme Q10, or triheptanoin, yielded negative or inconclusive results. However, future therapeutic strategies, aiming to restore mitochondrial biogenesis, improving the fission/fusion balance, and improving mitochondrial trafficking, could prove useful tools in improving the phenotype of Huntington's disease and, used in combination with genome-editing methods, could lead to a cure for the disease.

Assessment of the excretion of oxidative stress biomarkers and anabolic steroids based on sewage: A case study of college students and the general population

The use of wastewater-based epidemiology to evaluate the health and lifestyle of the population is a novel research interest. However, studies concerning the excretion of endogenous metabolites due to oxidative stress and the consumption of anabolic steroids have rarely been involved. In this study, we compared the effects of events such as final examination and sports meeting on the levels of four oxidative stress biomarkers (8-isoPGF_2α, HNE-MA, 8-OHdG, and HCY) and four prohibited anabolic steroids (Testosterone, Androstenedione, Boldenone, and Metandienone) in sewage, using university students and urban populations as studying target. It was found that the per capita mass load of the four oxidative stress biomarkers 8-isoPGF_2α, HNE-MA, 8-OHdG, and HCY in the sewage of Guangzhou urban area and university town were 256.6 ± 76.1, 9.4 ± 3.8, 1.1 ± 0.5, and 0.9 ± 0.4 mg/d/1000, respectively. The mean mass load of 8-isoPGF_2α was significantly higher than that before the COVID-19 pandemic (74.9 ± 29.6 mg/d/1000 people, P < 0.05). The per capita load levels of oxidative stress biomarkers were significantly higher (P < 0.05) during the 2022 exam week relative to the pre-exam period, indicating that the exams caused transient stress to students. The per capita mass load of androgenic steroids was 77.7 mg/d/1000 people. There was an increase in the per capita load level of androgenic steroids during the provincial sports meeting. In this study, we quantified the concentration of oxidative stress biomarkers and androgenic steroids in the sewage and better realized the application of WBE on the health level and lifestyle of the population during special events.

Early Hemorrhagic Transformation after Reperfusion Therapy in Patients with Acute Ischemic Stroke: Analysis of Risk Factors and Predictors

Background: The standard reperfusion therapy for acute ischemic stroke (AIS) is considered to be thrombolysis, but its application is limited by the high risk of hemorrhagic transformation (HT). This study aimed to analyze risk factors and predictors of early HT after reperfusion therapy (intravenous thrombolysis or mechanical thrombectomy). Material and methods: Patients with acute ischemic stroke who developed HT in the first 24 h after receiving rtPA thrombolysis or performing mechanical thrombectomy were retrospectively reviewed. They were divided into two groups, respectively, the early-HT group and the without-early-HT group based on cranial computed tomography performed at 24 h, regardless of the type of hemorrhagic transformation. Results: A total of 211 consecutive patients were enrolled in this study. Among these patients, 20.37% (n = 43; age: median 70.00 years; 51.2% males) had early HT. Multivariate analysis of independent risk factors associated with early HT found that male gender increased the risk by 2.7-fold, the presence of baseline high blood pressure by 2.4-fold, and high glycemic values by 1.2-fold. Higher values of NIHSS at 24 h increased the risk of hemorrhagic transformation by 1.18-fold, while higher values of ASPECTS at 24 h decreased the risk of hemorrhagic transformation by 0.6-fold. Conclusions: In our study, male gender, baseline high blood pressure, and high glycemic values, along with higher values of NIHSS were associated with the increased risk of early HT. Furthermore, the identification of early-HT predictors is critical in patients with AIS for the clinical outcome after reperfusion therapy. Predictive models to be used in the future to select more careful patients with a low risk of early HT need to be developed in order to minimize the impact of HT associated with reperfusion techniques.