Pathophysiology and Therapeutic Potential of NADPH Oxidases in Ischemic Stroke-Induced Oxidative Stress

Novel diagnostic biomarkers of oxidative stress, ferroptosis, immune infiltration characteristics and experimental validation in ischemic stroke

Ischemic stroke (IS) is a prominent type of cerebrovascular disease leading to death and disability in an aging society and is closely related to oxidative stress. Gene expression profiling (GSE222551) was derived from Gene Expression Omnibus (GEO), and 1934 oxidative stress (OS) genes were obtained from the GeneCards database. Subsequently, we identified 149 differentially expressed genes related to OS (DEOSGs). Finally, PTGS2, FOS, and RYR1 were identified as diagnostic markers of IS. Moreover, GSE16561 was used to validate the DEOSGs. Two diagnostic genes (PTGS2 and FOS) were significantly highly expressed, while RYR1 was significantly lowly expressed in the IS group. Remarkably, immune infiltration characteristics of these three genes were analyzed, and we found that PTGS2, FOS, and RYR1 were mainly correlated with Mast cells activated, Neutrophils, and Plasma cells, respectively. Next, we intersected three DEOSGs with the ferroptosis gene set, the findings revealed that only PTGS2 was a differentially expressed gene of ferroptosis. High PTGS2 expression levels in the infarcted cortex of middle cerebral artery occlusion (MCAO) rats were confirmed by immunofluorescence (IF), western blotting (WB), and Immunohistochemistry (IHC). Inhibition of PTGS2 clearly improved the neurological outcome of rats by decreasing infarct volume, neurological problems, and modified neurological severity scores following IS compared with the controls. The protective effect of silencing PTGS2 may be related to anti-oxidative stress and ferroptosis. In conclusion, this work may provide a new perspective for the research of IS, and further research based on PTGS2 may be a breakthrough.

Role of NLRP3 Inflammasome in Stroke Pathobiology: Current Therapeutic Avenues and Future Perspective

Neuroinflammation is a key pathophysiological feature of stroke-associated brain injury. A local innate immune response triggers neuroinflammation following a stroke via activating inflammasomes. The nucleotide-binding oligomerization domain leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) inflammasome has been heavily implicated in stroke pathobiology. Following a stroke, several stimuli have been suggested to trigger the assembly of the NLRP3 inflammasome. Recent studies have advanced the understanding and revealed several new players regulating NLRP3 inflammasome-mediated neuroinflammation. This article discussed recent advancements in NLRP3 assembly and highlighted stroke-induced mitochondrial dysfunction as a major checkpoint to regulating NLRP3 activation. The NLRP3 inflammasome activation leads to caspase-1-dependent maturation and release of IL-1β, IL-18, and gasdermin D. In addition, genetic or pharmacological inhibition of the NLRP3 inflammasome activation and downstream signaling has been shown to attenuate brain infarction and improve the neurological outcome in experimental models of stroke. Several drug-like small molecules targeting the NLRP3 inflammasome are in different phases of development as novel therapeutics for various inflammatory conditions, including stroke. Understanding how these molecules interfere with NLRP3 inflammasome assembly is paramount for their better optimization and/or development of newer NLRP3 inhibitors. In this review, we summarized the assembly of the NLRP3 inflammasome and discussed the recent advances in understanding the upstream regulators of NLRP3 inflammasome-mediated neuroinflammation following stroke. Additionally, we critically examined the role of the NLRP3 inflammasome-mediated signaling in stroke pathophysiology and the development of therapeutic modalities to target the NLRP3 inflammasome-related signaling for stroke treatment.

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

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

Genome editing approaches with CRISPR/Cas9: the association of NOX4 expression in breast cancer patients and effectiveness evaluation of different strategies of CRISPR/Cas9 to knockout Nox4 in cancer cells

BACKGROUND

The increasing prevalence of cancer detection necessitated practical strategies to deliver highly accurate, beneficial, and dependable processed information together with experimental results. We deleted the cancer biomarker NOX4 using three novel genetic knockout (KO) methods. Homology-directed repair (HDR), Dual allele HITI (Du-HITI) and CRISPR-excision were utilized in this study.

METHODS

The predictive value of the NOX4 expression profile was assessed using a combined hazard ratio (HR) with a 95% confidence interval (CI). With a 95% confidence interval, a pooled odd ratio (OR) was used to calculate the relationship between NOX4 expression patterns and cancer metastasis. There were 1060 tumor patients in all sixteen research that made up this meta-analysis. To stop the NOX4 from being transcribed, we employed three different CRISPR/Cas9-mediated knockdown methods. The expression of RNA was assessed using RT-PCR. We employed the CCK-8 assay, colony formation assays, and the invasion transwell test for our experiments measuring cell proliferation and invasion. Using a sphere-formation test, the stemness was determined. Luciferase reporter tests were carried out to verify molecular adhesion. Utilizing RT-qPCR, MTT, and a colony formation assay, the functional effects of NOX4 genetic mutation in CRISPR-excision, CRISPR-HDR, and CRISPR du-HITI knockdown cell lines of breast cancer were verified.

RESULTS

There were 1060 malignant tumors in the 16 studies that made up this meta-analysis. In the meta-analysis, higher NOX4 expression was linked to both a shorter overall survival rate (HR = 1.93, 95% CI 1.49-2.49, P < 0.001) and a higher percentage of lymph node metastases (OR = 3.22, 95% CI 2.18-4.29, P < 0.001). In breast carcinoma cells, it was discovered that NOX4 was overexpressed, and this increase was linked to a poor prognosis. The gain and loss-of-function assays showed enhanced NOX4 breast carcinoma cell proliferation, sphere-forming capacity, and tumor development. To activate transcription, the transcriptional factor E2F1 also attaches to the promoter region of the Nanog gene. The treatment group (NOX4 ablation) had substantially more significant levels of proapoptotic gene expression than the control group (P < 0.01). Additionally, compared to control cells, mutant cells expressed fewer antiapoptotic genes (P < 0.001). The du-HITI technique incorporated a reporter and a transcription termination marker into the two target alleles. Both donor vector preparation and cell selection were substantially simpler using this approach than with "CRISPR HDR" or "CRISPR excision." Furthermore, single-cell knockouts for both genotypes were created when this method was applied in the initial transfection experiment.

CONCLUSIONS

The NOX4 Knockout cell lines generated in this research may be used for additional analytical studies to reveal the entire spectrum of NOX4 activities. The du-HITI method described in this study was easy to employ and could produce homozygous individuals who were knockout for a specific protein of interest.

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.

Reperfusion and cytoprotective agents are a mutually beneficial pair in ischaemic stroke therapy: an overview of pathophysiology, pharmacological targets and candidate drugs focusing on excitotoxicity and free radical

Stroke is the second-leading cause of death and the leading cause of disability in much of the world. In particular, China faces the greatest challenge from stroke, since the population is aged quickly. In decades of clinical trials, no neuroprotectant has had reproducible efficacy on primary clinical end points, because reperfusion is probably a necessity for neuroprotection to be clinically beneficial. Fortunately, the success of thrombolysis and endovascular thrombectomy has taken us into a reperfusion era of acute ischaemic stroke (AIS) therapy. Brain cytoprotective agents can prevent detrimental effects of ischaemia, and therefore 'freeze' ischaemic penumbra before reperfusion, extend the time window for reperfusion therapy. Because reperfusion often leads to reperfusion injury, including haemorrhagic transformation, brain oedema, infarct progression and neurological worsening, cytoprotective agents will enhance the efficacy and safety of reperfusion therapy by preventing or reducing reperfusion injuries. Therefore, reperfusion and cytoprotective agents are a mutually beneficial pair in AIS therapy. In this review, we outline critical pathophysiological events causing cell death within the penumbra after ischaemia or ischaemia/reperfusion in the acute phase of AIS, focusing on excitotoxicity and free radicals. We discuss key pharmacological targets for cytoprotective therapy and evaluate the recent advances of cytoprotective agents going through clinical trials, highlighting multitarget cytoprotective agents that intervene at multiple levels of the ischaemic and reperfusion cascade.

Potential Role of Natural Antioxidants in Countering Reperfusion Injury in Acute Myocardial Infarction and Ischemic Stroke

Stroke and acute myocardial infarction are leading causes of mortality worldwide. The latter accounts for approximately 9 million deaths annually. In turn, ischemic stroke is a significant contributor to adult physical disability globally. While reperfusion is crucial for tissue recovery, it can paradoxically exacerbate damage through oxidative stress (OS), inflammation, and cell death. Therefore, it is imperative to explore diverse approaches aimed at minimizing ischemia/reperfusion injury to enhance clinical outcomes. OS primarily arises from an excessive generation of reactive oxygen species (ROS) and/or decreased endogenous antioxidant potential. Natural antioxidant compounds can counteract the injury mechanisms linked to ROS. While promising preclinical results, based on monotherapies, account for protective effects against tissue injury by ROS, translating these models into human applications has yielded controversial evidence. However, since the wide spectrum of antioxidants having diverse chemical characteristics offers varied biological actions on cell signaling pathways, multitherapy has emerged as a valuable therapeutic resource. Moreover, the combination of antioxidants in multitherapy holds significant potential for synergistic effects. This study was designed with the aim of providing an updated overview of natural antioxidants suitable for preventing myocardial and cerebral ischemia/reperfusion injuries.

The Promise of Niacin in Neurology

Niacin (vitamin B3) is an essential nutrient that treats pellagra, and prior to the advent of statins, niacin was commonly used to counter dyslipidemia. Recent evidence has posited niacin as a promising therapeutic for several neurological disorders. In this review, we discuss the biochemistry of niacin, including its homeostatic roles in NAD+ supplementation and metabolism. Niacin also has roles outside of metabolism, largely through engaging hydroxycarboxylic acid receptor 2 (Hcar2). These receptor-mediated activities of niacin include regulation of immune responses, phagocytosis of myelin debris after demyelination or of amyloid beta in models of Alzheimer's disease, and cholesterol efflux from cells. We describe the neurological disorders in which niacin has been investigated or has been proposed as a candidate medication. These are multiple sclerosis, Alzheimer's disease, Parkinson's disease, glioblastoma and amyotrophic lateral sclerosis. Finally, we explore the proposed mechanisms through which niacin may ameliorate neuropathology. While several questions remain, the prospect of niacin as a therapeutic to alleviate neurological impairment is promising.

OL-FS13 Alleviates Cerebral Ischemia-reperfusion Injury by Inhibiting miR-21-3p Expression

BACKGROUND

OL-FS13, a neuroprotective peptide derived from Odorrana livida, can alleviate cerebral ischemia-reperfusion (CI/R) injury, although the specific underlying mechanism remains to be further explored.

OBJECTIVE

The effect of miR-21-3p on the neural-protective effects of OL-FS13 was examined.

METHODS

In this study, the multiple genome sequencing analysis, double luciferase experiment, RT-qPCR, and Western blotting were used to explore the mechanism of OL-FS13.

RESULTS

Showed that over-expression of miR-21-3p against the protective effects of OL-FS13 on oxygen- glucose deprivation/re-oxygenation (OGD/R)-damaged pheochromocytoma (PC12) cells and in CI/R-injured rats. miR-21-3p was then found to target calcium/calmodulin-dependent protein kinase 2 (CAMKK2), and its overexpression inhibited the expression of CAMKK2 and phosphorylation of its downstream adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK), thereby inhibiting the therapeutic effects of OL-FS13 on OGD/R and CI/R. Inhibition of CAMKK2 also antagonized up-regulated of nuclear factor erythroid 2-related factor 2 (Nrf-2) by OL-FS13, thereby abolishing the antioxidant activity of the peptide.

CONCLUSION

Our results showed that OL-FS13 alleviated OGD/R and CI/R by inhibiting miR-21-3p to activate the CAMKK2/AMPK/Nrf-2 axis.

Discovery and validation of Ferroptosis-related molecular patterns and immune characteristics in Alzheimer's disease

Background

To date, the pathogenesis of Alzheimer's disease is still not fully elucidated. Much evidence suggests that Ferroptosis plays a crucial role in the pathogenesis of AD, but little is known about its molecular immunological mechanisms. Therefore, this study aims to comprehensively analyse and explore the molecular mechanisms and immunological features of Ferroptosis-related genes in the pathogenesis of AD.

Materials and methods

We obtained the brain tissue dataset for AD from the GEO database and downloaded the Ferroptosis-related gene set from FerrDb for analysis. The most relevant Hub genes for AD were obtained using two machine learning algorithms (Least absolute shrinkage and selection operator (LASSO) and multiple support vector machine recursive feature elimination (mSVM-RFE)). The study of the Hub gene was divided into two parts. In the first part, AD patients were genotyped by unsupervised cluster analysis, and the different clusters' immune characteristics were analysed. A PCA approach was used to quantify the FRGscore. In the second part: we elucidate the biological functions involved in the Hub genes and their role in the immune microenvironment by integrating algorithms (GSEA, GSVA and CIBERSORT). Analysis of Hub gene-based drug regulatory networks and mRNA-miRNA-lncRNA regulatory networks using Cytoscape. Hub genes were further analysed using logistic regression models.

Results

Based on two machine learning algorithms, we obtained a total of 10 Hub genes. Unsupervised clustering successfully identified two different clusters, and immune infiltration analysis showed a significantly higher degree of immune infiltration in type A than in type B, indicating that type A may be at the peak of AD neuroinflammation. Secondly, a Hub gene-based Gene-Drug regulatory network and a ceRNA regulatory network were successfully constructed. Finally, a logistic regression algorithm-based AD diagnosis model and Nomogram diagram were developed.

Conclusion

Our study provides new insights into the role of Ferroptosis-related molecular patterns and immune mechanisms in AD, as well as providing a theoretical basis for the addition of diagnostic markers for AD.

Pathophysiology of Ischemic Stroke: Noncoding RNA Role in Oxidative Stress

Stroke is a neurological disease that causes significant disability and death worldwide. Ischemic stroke accounts for 75% of all strokes. The pathophysiological processes underlying ischemic stroke include oxidative stress, the toxicity of excitatory amino acids, ion disorder, enhanced apoptosis, and inflammation. Noncoding RNAs (ncRNAs) may have a vital role in regulating the pathophysiological processes of ischemic stroke, as confirmed by the altered expression of ncRNAs in blood samples from acute ischemic stroke patients, animal models, and oxygen-glucose-deprived (OGD) cell models. Due to specific changes in expression, ncRNAs can potentially be biomarkers for the diagnosis, treatment, and prognosis of ischemic stroke. As an important brain cell component, glial cells mediate the occurrence and progression of oxidative stress after ischemic stroke, and ncRNAs are an irreplaceable part of this mechanism. This review highlights the impact of ncRNAs in the oxidative stress process of ischemic stroke. It focuses on specific ncRNAs that underlie the pathophysiology of ischemic stroke and have potential as diagnostic biomarkers and therapeutic targets.

Identification of changed proteins by retinoic acid in cerebral ischemic damage: a proteomic study

Ischemic stroke is a severe neurodegenerative disease with a high mortality rate. Retinoic acid is a representative metabolite of vitamin A. It has many beneficial effects including anti-inflammatory, anti-apoptotic, and neuroprotective effects. The purpose of this study is to identify specific proteins that are regulated by retinoic acid in ischemic stroke. Middle cerebral artery occlusion (MCAO) was performed to induce focal cerebral ischemia. Retinoic acid (5 mg/kg) or vehicle was injected intraperitoneally into male rats for four days prior to MCAO operation. Neurobehavioral tests were performed 24 hr after MCAO and the cerebral cortex was collected for proteomic study. Retinoic acid alleviates neurobehavioral deficits and histopathological changes caused by MCAO. Furthermore, we identified various proteins that were altered by retinoic acid in MCAO damage. Among these identified proteins, adenosylhomocysteinase, isocitrate dehydrogenase [NAD+] subunit α, glycerol-3-phosphate dehydrogenase, Rab GDP dissociation inhibitor β, and apolipoprotein A1 were down-regulated in MCAO animals with vehicle treatment, whereas retinoic acid treatment alleviated these reductions. However, heat shock protein 60 was up-regulated in MCAO animals with vehicle, while retinoic acid treatment attenuated this increase. The changes in these expressions were confirmed by reverse transcription-PCR. These proteins regulate cell metabolism and mediate stress responses. Our results demonstrated that retinoic acid attenuates the neuronal damage by MCAO and regulates the various protein expressions that are involved in the survival of cells. Thus, we can suggest that retinoic acid exerts neuroprotective effects on focal cerebral ischemia by modulation of specific proteins.

OL-FS13 alleviates experimental cerebral ischemia-reperfusion injury

Cerebral ischemia-reperfusion (I/R) is the main cause of neurological injury after stroke. However, existing treatments for I/R injury are relatively poor, and relevant drugs need to be further explored. Amphibians have received increasing attention as a resource bank of bioactive peptides. However, reports on neuroprotective peptides from amphibians remain extremely rare. Here, we identified a new neuroprotective peptide (OL-FS13, amino acid sequence: FSLLLTWWRRRVC) from the odorous frog species Odorrana livida using a constructed cDNA library. OL-FS13 significantly improving infarct volume, behavioral and histological abnormalities in rats, and also showed neuroprotective activities in PC12 cell (by oxygen glucose deprivation/reoxygenation, OGD/R). Mechanistically, OL-FS13 increased the level of antioxidative enzymes to resist oxidative stress and alleviated endoplasmic reticulum (ER) stress induced by I/R and OGD/R. The use of ML385 (Nrf2 inhibitor) indicated that OL-FS13 relieved nerve damage caused by oxidative and ER stress by increasing the nuclear displacement of Nrf2. Collectively, this research provides a novel drug candidate for the clinical cerebral I/R curation.

Mechanisms Underlying Curcumin-Induced Neuroprotection in Cerebral Ischemia

Ischemic stroke is the leading cause of death and disability worldwide, and restoring the blood flow to ischemic brain tissues is currently the main therapeutic strategy. However, reperfusion after brain ischemia leads to excessive reactive oxygen species production, inflammatory cell recruitment, the release of inflammatory mediators, cell death, mitochondrial dysfunction, endoplasmic reticulum stress, and blood–brain barrier damage; these pathological mechanisms will further aggravate brain tissue injury, ultimately affecting the recovery of neurological functions. It has attracted the attention of researchers to develop drugs with multitarget intervention effects for individuals with cerebral ischemia. A large number of studies have established that curcumin plays a significant neuroprotective role in cerebral ischemia via various mechanisms, including antioxidation, anti-inflammation, anti-apoptosis, protection of the blood–brain barrier, and restoration of mitochondrial function and structure, restoring cerebral circulation, reducing infarct volume, improving brain edema, promoting blood–brain barrier repair, and improving the neurological functions. Therefore, summarizing the results from the latest literature and identifying the potential mechanisms of action of curcumin in cerebral ischemia will serve as a basis and guidance for the clinical applications of curcumin in the future.

Neuronal Death Mechanisms and Therapeutic Strategy in Ischemic Stroke

Ischemic stroke caused by intracranial vascular occlusion has become increasingly prevalent with considerable mortality and disability, which gravely burdens the global economy. Current relatively effective clinical treatments are limited to intravenous alteplase and thrombectomy. Even so, patients still benefit little due to the short therapeutic window and the risk of ischemia/reperfusion injury. It is therefore urgent to figure out the neuronal death mechanisms following ischemic stroke in order to develop new neuroprotective strategies. Regarding the pathogenesis, multiple pathological events trigger the activation of cell death pathways. Particular attention should be devoted to excitotoxicity, oxidative stress, and inflammatory responses. Thus, in this article, we first review the principal mechanisms underlying neuronal death mediated by these significant events, such as intrinsic and extrinsic apoptosis, ferroptosis, parthanatos, pyroptosis, necroptosis, and autophagic cell death. Then, we further discuss the possibility of interventions targeting these pathological events and summarize the present pharmacological achievements.

The correlation of lncRNA SNHG16 with inflammatory cytokines, adhesion molecules, disease severity, and prognosis in acute ischemic stroke patients

Background

Long non‐coding RNA small nucleolar RNA host gene 16 (lncRNA SNHG16) is involved in the pathogenesis of acute ischemic stroke (AIS) through the regulation of brain endothelial cell viability, inflammation, atherosclerotic plaque formation, and neural apoptosis. This study aimed to evaluate the prognostic value of lncRNA SNHG16 in AIS patients.

Methods

Newly diagnosed AIS patients (N = 120) were serially recruited. Their lncRNA SNHG16 expressions in peripheral blood mononuclear cells (PBMCs) were detected by reverse transcription‐quantitative polymerase chain reaction (RT‐qPCR); serum inflammatory cytokines and adhesion molecules were determined using enzyme‐linked immunosorbent assay (ELISA). The accumulating recurrence‐free survival (RFS) and overall survival (OS) were analyzed. Moreover, controls (N = 60) were recruited and their lncRNA SNHG16 expressions in PBMCs were detected.

Results

LncRNA SNHG16 was declined in AIS patients compared to controls (p < 0.001). Moreover, lncRNA SNHG16 was not related to any comorbidities in AIS patients (all p > 0.05). Interestingly, lncRNA SNHG16 was negatively related to tumor necrosis factor alpha (TNF‐α) (p < 0.001), interleukin 6 (IL‐6) (p = 0.013), and intracellular cell adhesion molecule‐1 (ICAM‐1) (p = 0.024), while positively correlated with interleukin 10 (IL‐10) (p = 0.022) in AIS patients. Besides, lncRNA SNHG16 was inversely associated with the National Institutes of Health Stroke Scale (NIHSS) score in AIS patients (p = 0.003). During the follow‐up period, in 14 (11.7%) patients occurred recurrence and 5 (4.2%) patients died. Unexpectedly, lncRNA SNHG16 was not associated with accumulating RFS (p = 0.103) or OS (p = 0.150) in AIS patients.

Conclusion

LncRNA SNHG16 relates to lower inflammatory cytokines, adhesion molecules, and milder disease severity, but fails to predict prognosis in AIS patients.

Insight Into the Mechanism of Exercise Preconditioning in Ischemic Stroke

Exercise preconditioning has attracted extensive attention to induce endogenous neuroprotection and has become the hotspot in neurotherapy. The training exercise is given multiple times before cerebral ischemia, effectively inducing ischemic tolerance and alleviating secondary brain damage post-stroke. Compared with other preconditioning methods, the main advantages of exercise include easy clinical operation and being readily accepted by patients. However, the specific mechanism behind exercise preconditioning to ameliorate brain injury is complex. It involves multi-pathway and multi-target regulation, including regulation of inflammatory response, oxidative stress, apoptosis inhibition, and neurogenesis promotion. The current review summarizes the recent studies on the mechanism of neuroprotection induced by exercise, providing the theoretical basis of applying exercise therapy to prevent and treat ischemic stroke. In addition, we highlight the various limitations and future challenges of translational medicine from fundamental study to clinical application.

Inhibition of Autophagy Facilitates XY03-EA-Mediated Neuroprotection against the Cerebral Ischemia/Reperfusion Injury in Rats

Objective. L-3-n-Butylphthalide (NBP) is used to treat moderate and severe acute ischemia stroke. A previous screening study indicates that XY03-EA, a novel derivative of NBP, is more potent than NBP in the oxyradical scavenging capacity. In this study, in vivo and in vitro ischemia/reperfusion (I/R) models were used to test whether the XY03-EA offered therapeutic benefits in the ischemic stroke and explore the underlying mechanism of action. Methods. For this purpose, behavioral scores, cerebral infarct volume, cerebral blood flow, oxidative stress levels, inflammatory factor expression, energy metabolism levels, and autophagy activation were estimated in the rat middle cerebral artery occlusion and reperfusion (MCAO/R) model. The nonhuman primate MCAO/R model was conducted to validate the therapeutic effect of XY03-EA applied for 3 weeks. The neurological deficit score (NDS) progression rate and the infarct volume were continuously recorded on days 3, 7, 14, and 21. The PC-12 cell OGD/R model was used to assess the cell survival rate, reactive oxygen species (ROS) levels, the expression of autophagy execution molecules, and the activation of autophagy-related signaling pathways. Results. XY03-EA decreased the cerebral injuries and NDS by increasing cerebral blood flow, improving brain energy metabolism, accelerating ROS clearance, suppressing inflammatory responses, and inhibiting autophagy in the MCAO/R model rats. In the nonhuman primate MCAO/R model, the treatment of XY03-EA for 3 weeks could significantly inhibit the NDS progression rate and indicate a positive trend to reduce the infarct volume in a dose-dependent way. Mechanistically, XY03-EA inhibited ROS-dependent autophagy activation and thereby protected the PC-12 cells from the autophagic cell death induced by OGD/R. Conclusions. In this study, we found that XY03-EA alleviated the cerebral I/R injuries in rats and nonhuman primates. Our results demonstrated that XY03-EA exerted neuroprotective effects against the ROS-mediated autophagic neurocyte death and had great potential for the treatment of ischemic stroke.

Nrf2 protects against cerebral ischemia-reperfusion injury by suppressing programmed necrosis and inflammatory signaling pathways

Background

The NOD-like receptor family pyrin domain-containing 3 (NLRP3) -mediated neuroinflammation is linked to neuronal necroptosis in cerebral ischemia-reperfusion (I/R) injury, especially in cerebral ischemic penumbra. This study was designed to investigate the regulation of nuclear factor E2-related factor-2 (Nrf2) on NLRP3 inflammasome in necroptosis signal pathway induced by I/R injury.

Methods

We investigated the mechanisms of Nrf2-negative regulation in necroptosis signaling pathway by using middle cerebral artery occlusion (MCAO) with Q-VD-OPH injected intraperitoneally. The protein level of the NLRP3 inflammasome was detected by western blot with Nrf2 knockdown and overexpression. NLRP3 inflammasome activation was Reactive oxygen species (ROS) dependent, and the protein level was regulated when N-acetylcysteine (NAC) and adenosine triphosphate (ATP) were selected as tools for regulating ROS.

Results

We demonstrated the negative regulation of Nrf2 on NLRP3 inflammasome activation in Q-VD-OPH-induced necroptosis in cerebral artery I/R injury through Lentivirus-mediated RNA Interferenc, which mediated knockdown and overexpression of Nrf2. NLRP3 inflammasome activation was sensitive to both ATP-mediated ROS level increases and NAC-mediated ROS inhibition, suggesting that ROS is associated with the activation of NLRP3 inflammasome in necroptosis. In addition, Nrf2-induced NAD(P)H quinone dehydrogenase 1 (NQO1) was involved in the inhibition of NLRP3 inflammasome activation. These results suggest that Nrf2 regulates NQO1 to attenuate ROS, which negatively regulates NLRP3 inflammasome.

Conclusions

Nrf2/NQO1 was an inhibitor of ROS-induced NLRP3 inflammasome activation in Q-VD-OPH-induced necroptosis following cerebral I/R injury. Therefore, NLRP3 inflammasome could be a potential therapeutic target for cerebral ischemia.

RS4673 and pon1 level in blood plasma - new prospects in prediction and early diagnostics of anthracycline-mediated cardiotoxicity

The purpose of this study was to research the effectiveness of molecular genetic tests based on the determination of the rs4673 CYBA polymorphism (c.242C>T) and the level of paraoxonase 1 (PON1) in the blood plasma of patients with breast cancer (BC) for predicting and diagnosing anthracycline-mediated cardiotoxicity (AMC). The genotyping of rs4673 CYBA (c.242C>T) and the study of the PON1 level in the blood plasma of 280 patients of the Caucasian type with a histologically verified diagnosis of breast cancer, who received complex treatment on the basis of the National Medical Research Center of Oncology, were carried out. Based on the results of observation for at least 8 months, two groups were identified: group 1 (257 people) without diagnosed cardiovascular changes; group 2 (23 people) - patients with subacute and early chronic AMC. It was found that carriers of the rs4673 polymorphism increase the likelihood of developing AMC by 6.8 times (p = 0.001). In the blood plasma of both groups of patients, an increase in the level of PON1 was described after the fourth course compared to the initial level (group 1 - p = 0.036, group 2 - p = 0.048). The level of the studied enzyme was higher in the blood plasma of patients with diagnosed AMC compared with patients without cardiovascular complications (before chemotherapy - p = 0.001, after the fourth course - p = 0.023). The test based on the measurement of the concentration of PON1 in the blood plasma of patients after the fourth course of chemotherapy was distinguished by high quality metrics: sensitivity - 100%, specificity - 70.8%, area under the ROC-curve (AUC) - 0.825 with a threshold level of PON1 equal to 2, 9 ng/μL. The presence of the T/T genotype caused a high level of PON1 in the blood plasma after the fourth course of chemotherapy (p = 0.012). The results of our work are of undoubted practical importance, since they allow us to obtain data on the prognosis and diagnosis of a patient in a short time, which can later be verified using clinical and instrumental methods.

N-Acetyl-Aspartyl-Glutamate in Brain Health and Disease

N-acetyl-aspartyl-glutamate (NAAG) is the most abundant dipeptide in the brain, where it acts as a neuromodulator of glutamatergic synapses by activating presynaptic metabotropic glutamate receptor 3 (mGluR3). Recent data suggest that NAAG is selectively localized to postsynaptic dendrites in glutamatergic synapses and that it works as a retrograde neurotransmitter. NAAG is released in response to glutamate and provides the postsynaptic neuron with a feedback mechanisms to inhibit excessive glutamate signaling. A key regulator of synaptically available NAAG is rapid degradation by the extracellular enzyme glutamate carboxypeptidase II (GCPII). Increasing endogenous NAAG—for instance by inhibiting GCPII—is a promising treatment option for many brain disorders where glutamatergic excitotoxicity plays a role. The main effect of NAAG occurs through increased mGluR3 activation and thereby reduced glutamate release. In the present review, we summarize the transmitter role of NAAG and discuss the involvement of NAAG in normal brain physiology. We further present the suggested roles of NAAG in various neurological and psychiatric diseases and discuss the therapeutic potential of strategies aiming to enhance NAAG levels.

Unifying mechanism behind the onset of acquired epilepsy

Acquired epilepsy (AE) can result from a number of brain insults and neurological diseases with wide etiological diversity sharing one common outcome of brain epileptiform activity. This implies that despite their disparity, all these initiating pathologies affect the same fundamental brain functions underlying network excitability. Identifying such mechanisms and their availability as therapeutic targets would help develop an effective strategy for epileptogenesis prevention. In this opinion article, we propose that the vicious cycle of NADPH oxidase (NOX)-mediated oxidative stress and glucose hypometabolism is the underlying cause of AE, as available data reveal a critical role for both pathologies in epileptogenesis and the process of seizure initiation. Altogether, here we present a novel view on the mechanisms behind the onset of AE and identify therapeutic targets for potential clinical applications.

Oxidative Stress in the Brain: Basic Concepts and Treatment Strategies in Stroke

The production of free radicals is inevitably associated with metabolism and other enzymatic processes. Under physiological conditions, however, free radicals are effectively eliminated by numerous antioxidant mechanisms. Oxidative stress occurs due to an imbalance between the production and elimination of free radicals under pathological conditions. Oxidative stress is also associated with ageing. The brain is prone to oxidative damage because of its high metabolic activity and high vulnerability to ischemic damage. Oxidative stress, thus, plays a major role in the pathophysiology of both acute and chronic pathologies in the brain, such as stroke, traumatic brain injury or neurodegenerative diseases. The goal of this article is to summarize the basic concepts of oxidative stress and its significance in brain pathologies, as well as to discuss treatment strategies for dealing with oxidative stress in stroke.

Expression of Endothelial NOX5 Alters the Integrity of the Blood-Brain Barrier and Causes Loss of Memory in Aging Mice

Blood-Brain barrier (BBB) disruption is a hallmark of central nervous system (CNS) dysfunction, and oxidative stress is one of the molecular mechanisms that may underlie this process. NADPH oxidases (NOX) are involved in oxidative stress-mediated vascular dysfunction and participate in the pathophysiology of its target organs. The NADPH oxidase 5 (NOX5) isoform is absent in rodents, and although little is known about the role it may play in disrupting the BBB, it has recently been implicated in experimental stroke. Our aim was to investigate the role of NADPH oxidase 5 (NOX5) in promoting vascular alterations and to identify its impact on the cognitive status of aged mice. No differences were detected in the arterial blood pressure or body weight between knock-in mice expressing endothelial NOX5 and the control mice. The Morris water maze test showed memory impairments in the aged knock-in mice expressing NOX5 compared with their control littermates. For assessing the BBB integrity, we studied the protein expression of two tight junction (TJ) proteins: Zonula occludens-1 (ZO-1) and occludin. Compared to the control animals, Aged NOX5 mice exhibited reduced levels of both proteins, demonstrating an alteration of the BBB integrity. Our data indicate that vascular NOX5 may favor behavioral changes with aging through oxidative stress-mediated BBB breakdown.

The critical roles of histone deacetylase 3 in the pathogenesis of solid organ injury

Histone deacetylase 3 (HDAC3) plays a crucial role in chromatin remodeling, which, in turn, regulates gene transcription. Hence, HDAC3 has been implicated in various diseases, including ischemic injury, fibrosis, neurodegeneration, infections, and inflammatory conditions. In addition, HDAC3 plays vital roles under physiological conditions by regulating circadian rhythms, metabolism, and development. In this review, we summarize the current knowledge of the physiological functions of HDAC3 and its role in organ injury. We also discuss the therapeutic value of HDAC3 in various diseases.

Salivary Biomarkers of Oxidative Stress and Inflammation in Stroke Patients: From Basic Research to Clinical Practice

Cerebral stroke is a serious worldwide health problem, as can be seen by the global epidemic of the disease. In this disorder, when the blood flow is compromised by ruptures or blocked arteries, sudden death of neurons is observed as a result of a lack of oxygen and nutrients. Numerous severe problems and frequent complications also exist in stroke patients; therefore, there is an urgent need to develop new therapeutic, diagnostic, and prognostic methods for the disease. At present, the diagnosis of stroke is based on a neurological examination, medical history, and neuroimaging, due to the fact that rapid and noninvasive diagnostic tests are unavailable. Nevertheless, oxidative stress and inflammation are considered key factors in stroke pathogenesis. Oxygen free radicals are responsible for oxidation of lipids, proteins, and DNA/RNA, which in turn contributes to oxidative damage of the brain. Toxic products of the oxidation reactions act cytostatically on the cell by damaging cell membranes and leading to neuronal death by apoptosis or necrosis. Thus, it seems that redox/inflammatory biomarkers might be used in the diagnosis of the disease. Nowadays, saliva is of increasing interest in clinical laboratory medicine. Redox biomarkers could be obtained easily, noninvasively, cheaply, and stress-free from saliva. This minireview is aimed at presenting the current knowledge concerning the use of salivary biomarkers of oxidative stress and inflammation in the diagnosis and prognosis of stroke.