Hyperbaric Oxygen Reduces Infarction Volume and Hemorrhagic Transformation Through ATP/NAD+/Sirt1 Pathway in Hyperglycemic Middle Cerebral Artery Occlusion Rats

Neuroprotective potential for mitigating ischemia-reperfusion-induced damage

Reperfusion following cerebral ischemia causes both structural and functional damage to brain tissue and could aggravate a patient's condition; this phenomenon is known as cerebral ischemia-reperfusion injury. Current studies have elucidated the neuroprotective role of the sirtuin protein family (Sirtuins) in modulating cerebral ischemia-reperfusion injury. However, the potential of utilizing it as a novel intervention target to influence the prognosis of cerebral ischemia-reperfusion injury requires additional exploration. In this review, the origin and research progress of Sirtuins are summarized, suggesting the involvement of Sirtuins in diverse mechanisms that affect cerebral ischemia-reperfusion injury, including inflammation, oxidative stress, blood-brain barrier damage, apoptosis, pyroptosis, and autophagy. The therapeutic avenues related to Sirtuins that may improve the prognosis of cerebral ischemia-reperfusion injury were also investigated by modulating Sirtuins expression and affecting representative pathways, such as nuclear factor-kappa B signaling, oxidative stress mediated by adenosine monophosphate-activated protein kinase, and the forkhead box O. This review also summarizes the potential of endogenous substances, such as RNA and hormones, drugs, dietary supplements, and emerging therapies that regulate Sirtuins expression. This review also reveals that regulating Sirtuins mitigates cerebral ischemia-reperfusion injury when combined with other risk factors. While Sirtuins show promise as a potential target for the treatment of cerebral ischemia-reperfusion injury, most recent studies are based on rodent models with circadian rhythms that are distinct from those of humans, potentially influencing the efficacy of Sirtuins-targeting drug therapies. Overall, this review provides new insights into the role of Sirtuins in the pathology and treatment of cerebral ischemia-reperfusion injury.

Identification and analysis of key immunity-related genes in experimental ischemic stroke

The regulation of the immune system and the occurrence of inflammation are vital factors in the pathophysiology of ischemic stroke. This study aims to screen target molecules which play key roles in alleviating the brain injury following ischemic stroke via regulating neuroinflammation. Several bioinformatics methods were used to identify immune-related genes in ischemic stroke. A total of 218 genes were identified as differentially expressed genes within the GSE97537 dataset. By performing GO, KEGG, and GSEA analyses, DEGs were mainly enriched in pathways related to immunity and inflammation. By utilizing the MCODE plugin in conjunction with Cytoscape software, a total of six crucial genes were identified, including C1qb, C1qc, Fcer1g, Fcgr3a, Tyrobp, and CD14. Based on the above crucial genes, 13 miRNAs were predicted. Furthermore, 71 potential drugs with therapeutic properties that target the crucial genes were screened, including lovastatin, ASPIRIN, and PREDNISOLONE. Moreover, the results of RT-qPCR showed that compared with Sham group, the expressions of C1qb, C1qc, Fcer1g, Fcgr3a, Tyrobp, and CD14 in MCAO group were significantly increased, which was consistent with the expression trend of validation dataset and training dataset. In conclusion, immune-related genes may play a key role in ischemic stroke. In addition, six crucial genes were identified as potential biomarkers and 71 promising drugs were screened to treat ischemic stroke patients.

ROS exhaustion reverses the effects of hyperbaric oxygen on hemorrhagic transformation through reactivating microglia in post-stroke hyperglycemic mice

Acute ischemic stroke (AIS) is a major global health concern due to its high mortality and disability rates. Hemorrhagic transformation, a common complication of AIS, leads to poor prognosis yet lacks effective treatments. Preclinical studies indicate that hyperbaric oxygen (HBO) treatment within 12 h of AIS onset alleviates ischemia/reperfusion injuries, including hemorrhagic transformation. However, clinical trials have yielded conflicting results, suggesting some underlying mechanisms remain unclear. In this study, we confirmed that HBO treatments beginning within 1 h post reperfusion significantly alleviated the haemorrhage and neurological deficits in hyperglycemic transient middle cerebral arterial occlusion (tMCAO) mice, partly due to the inhibition of the NLRP3 inflammasome-mediated pro-inflammatory response in microglia. Notably, reactive oxygen species (ROS) mediate the anti-inflammatory and protective effect of early HBO treatment, as edaravone and N-Acetyl-L-Cysteine (NAC), two commonly used antioxidants, reversed the suppressive effect of HBO treatment on NLRP3 inflammasome-mediated inflammation in microglia. Furthermore, NAC countered the protective effect of early HBO treatment in tMCAO mice with hyperglycemia. These findings support that early HBO treatment is a promising intervention for AIS, however, caution is warranted when combining antioxidants with HBO treatment. Further assessments are needed to clarify the role of antioxidants in HBO therapy for AIS.

ADP-ribosylation, a multifaceted modification: Functions and mechanisms in aging and aging-related diseases

Aging, a complex biological process, plays key roles the development of multiple disorders referred as aging-related diseases involving cardiovascular diseases, stroke, neurodegenerative diseases, cancers, lipid metabolism-related diseases. ADP-ribosylation is a reversible modification onto proteins and nucleic acids to alter their structures and/or functions. Growing evidence support the importance of ADP-ribosylation and ADP-ribosylation-associated enzymes in aging and age-related diseases. In this review, we summarized ADP-ribosylation-associated proteins including ADP-ribosyl transferases, the ADP-ribosyl hydrolyses and ADP-ribose binding domains. Furthermore, we outlined the latest knowledge about regulation of ADP-ribosylation in the pathogenesis and progression of main aging-related diseases, organism aging and cellular senescence, and we also speculated the underlying mechanisms to better disclose this novel molecular network. Moreover, we discussed current issues and provided an outlook for future research, aiming to revealing the unknown bio-properties of ADP-ribosylation, and establishing a novel therapeutic perspective in aging-related diseases and health aging via targeting ADP-ribosylation.

Predictive model for the risk of hemorrhagic transformation after rt-PA intravenous thrombolysis in patients with acute ischemic stroke: A systematic review and meta-analysis

OBJECTIVE

To systematically review the risk prediction model of Hemorrhages Transformation (HT) after intravenous thrombolysis in patients with Acute Ischemic Stroke (AIS).

METHODS

Web of Science, The Cochrane Library, PubMed, Embase, CINAHL, CNKI, CBM, WanFang, and VIP were searched from inception to February 25, 2023 for literature related to the risk prediction model for HT after thrombolysis in AIS.

RESULTS

A total of 17 included studies contained 26 prediction models, and the AUC of all models at the time of modeling ranged from 0.662 to 0.9854, 16 models had AUC>0.8, indicating that the models had good predictive performance. However, most of the included studies were at risk of bias. the results of the Meta-analysis showed that atrial fibrillation (OR=2.72, 95% CI:1.98-3.73), NIHSS score (OR=1.09, 95% CI:1.07-1.11), glucose (OR=1.12, 95% CI:1.06-1.18), moderate to severe leukoaraiosis (OR=3.47, 95% CI:1.61-7.52), hyperdense middle cerebral artery sign (OR=2.35, 95% CI:1.10-4.98), large cerebral infarction (OR=7.57, 95% CI:2.09-27.43), and early signs of infarction (OR=4.80, 95% CI:1.74-13.25) were effective predictors of HT after intravenous thrombolysis in patients with AIS.

CONCLUSIONS

The performance of the models for HT after thrombolysis in patients with AIS in the Chinese population is good, but there is some risk of bias. Future post-intravenous HT conversion prediction models for AIS patients in the Chinese population should focus on predictors such as atrial fibrillation, NIHSS score, glucose, moderate to severe leukoaraiosis, hyperdense middle cerebral artery sign, massive cerebral infarction, and early signs of infarction.

Hyperbaric oxygen therapy for poststroke insomnia: a systematic review and meta-analysis protocol

INTRODUCTION

Insomnia stands as a frequent consequence of a cerebrovascular event, afflicting a substantial fraction of those who endure the aftermath of stroke. The ramifications of insomnia following a stroke can further exacerbate cognitive and behavioural anomalies while hindering the process of neurological convalescence. While several randomised controlled trials (RCTs) have scrutinised the effects of hyperbaric oxygen therapy (HBOT) on poststroke insomnia, the advantages and drawbacks persist in a state of ambiguity. We advocate for a systematic review and meta-analysis of randomised clinical trials to comprehensively evaluate the effectiveness and safety of HBOT in the context of poststroke insomnia.

METHODS AND ANALYSIS

A systematic search will be conducted from nine major databases (PubMed, Web of Science, EMBASE, VIP Information Database, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, China Biomedical Literature Database and Wanfang Database, Physiotherapy Evidence Database (PEDro)) for HBOT for poststroke insomnia of RCTs. The search procedures will adhere to a rigorous approach, commencing from the inception date of each database and continuing until 1 November 2023, with inquiries conducted exclusively in English and Chinese. The primary outcome will focus on the alteration in the quality of sleep while secondary outcomes will encompass the evaluation of adverse events and the rate of reoccurrence. The process of selecting studies, extracting data and evaluating the quality of research will be carried out independently by two reviewers. The quality of the included literature will be assessed using the tools of the Cochrane Collaboration. Meta-analysis will be performed by using RevMan V.5.4 and STATA V.16.0.b software. Finally, the quality of evidence will be assessed using the Grading of Recommendations, Assessment, Development and Evaluation method.

ETHICS AND DISSEMINATION

As all data are derived from published investigations via databases without direct patient contact, ethical approval is obviated in this study. The scientific studies will be published in professional academic publications.

PROSPERO REGISTRATION NUMBER

CRD42023468442.

Trifluoperazine regulates blood-brain barrier permeability via the MLCK/p-MLC pathway to promote ischemic stroke recovery

Blood-brain barrier (BBB) disruption following ischemic stroke (IS) can induce significant aftereffects. Elevated calmodulin (CaM) expression following stroke causes calcium overload-a key contributor to BBB collapse. Trifluoperazine (TFP), a CaM inhibitor, reduces CaM overexpression following IS. However, it remains unclear whether TFP participates in BBB repair after IS. We administered TFP to mice subjected to middle cerebral artery occlusion (MCAO) and bEnd.3 cells subjected to oxygen-glucose deprivation (OGD). TFP treatment in MCAO mice reduced cerebral CaM expression and infarct size and decreased BBB permeability. OGD-treated bEnd.3 cells showed significantly increased CaM protein levels and reduced tight junction (TJ) protein levels; these changes were reversed by TFP treatment. Our results found that TFP administration in mice inhibited actin contraction following cerebral ischemia-reperfusion by suppressing the MLCK/p-MLC pathway, thereby attenuating cell retraction, improving TJ protein integrity, and reducing BBB permeability. Consequently, this treatment may promote neurological function recovery after IS.

Influence of hyperbaric oxygen therapy-specialized care on limb motor function and mental state of cerebral infarction patients with hemiplegia

BACKGROUND

Currently, cerebral infarction (CI) is mainly treated by emergency craniotomy or conservative treatment. However, some studies have questioned the functional recovery of patients after hyperbaric oxygen therapy (HBOT)-specialized care.

OBJECTIVE

This paper mainly explores the influence of HBOT-specialized care on limb motor function (LMF) and mental state of CI patients with hemiplegia.

METHODS

The medical records of 113 CI patients with hemiplegia treated in our hospital from March 2020 to March 2022 were collected. Of these, 53 received routine care nursing (conventional group) and 60 cases were given HBOT-specialized care (research group). Patient general data, scores of Fugl-Meyer Assessment (FMA), National Institutes of Health Stroke Scale (NIHSS), Self-rating Anxiety/Depression Scale (SAS/SDS) and Barthel Index (BI), and nursing efficiency were comparatively analyzed.

RESULTS

The two groups showed comparability in general data. FMA and BI scores were increased in the research group after rehabilitation treatment, higher than the baseline and those of the conventional group, while NIHSS, SAS, and SDS scores were reduced, lower compared with baseline and those of the conventional group. In addition, significantly higher nursing efficiency was determined in the research group.

CONCLUSION

HBOT-specialized care has beneficial effects on LMF, mental state, negative emotions and self-care ability of CI patients with hemiplegia and can enhance nursing efficacy, which deserves clinical popularization.

Attention Deficit Hyperactivity Disorder Misdiagnosis: Why Medical Evaluation Should Be a Part of ADHD Assessment

INTRODUCTION

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that interferes with multiple aspects of daily functioning and is associated with impairments in several domains. It may affect academic, educational, vocational, social, emotional, interpersonal, and health domains, and worsen risks to health outcomes.

OBJECTIVE

To identify and discuss medical conditions that commonly present with symptoms resembling ADHD.

METHOD

This review is selective and not systematic. It is conducted through a focused literature search through PubMed, Google Scholar, and EMBASE. Search term included "ADHD misdiagnosis", "medical conditions with ADHD like symptoms", "ADHD AND medical problems".

EXCLUSION

giftedness, high IQ, and any article that does not list medical conditions. The limits applied were the following: the work must have been published in the past 20 years, be on humans, and be in the English language.

RESULTS

There are several medical conditions that can be misdiagnosed as ADHD and may show a similar presentation to ADHD, particularly with inattentive symptoms. Examples include, but are not limited to, absence seizure disorder, diabetes, thyroid dysfunction, sleep deprivation, post-concussion states, inflammatory bowel disease, iron deficiency states and anemia, and disordered breathing.

CONCLUSIONS

Our review suggests that a thorough medical evaluation should be conducted prior to the diagnosis of ADHD. Allied health professionals and psychologists who diagnose ADHD should seek medical clearance from a physician prior to making the ADHD diagnosis in order to reduce misdiagnosis rates and improve patient outcomes. ADHD diagnosis should follow guidelines and be carried out under a systematic standardized approach. A full medical evaluation should be conducted to assess for medical conditions that may look like ADHD or be associated with ADHD.

Selenium inhibits ferroptosis in hyperglycemic cerebral ischemia/reperfusion injury by stimulating the Hippo pathway

Hyperglycemia can exacerbate cerebral ischemia/reperfusion (I/R) injury, and the mechanism involves oxidative stress, apoptosis, autophagy and mitochondrial function. Our previous research showed that selenium (Se) could alleviate this injury. The aim of this study was to examine how selenium alleviates hyperglycemia-mediated exacerbation of cerebral I/R injury by regulating ferroptosis. Middle cerebral artery occlusion (MCAO) and reperfusion models were established in rats under hyperglycemic conditions. An in vitro model of hyperglycemic cerebral I/R injury was created with oxygen-glucose deprivation and reoxygenation (OGD/R) and high glucose was employed. The results showed that hyperglycemia exacerbated cerebral I/R injury, and sodium selenite pretreatment decreased infarct volume, edema and neuronal damage in the cortical penumbra. Moreover, sodium selenite pretreatment increased the survival rate of HT22 cells under OGD/R and high glucose conditions. Pretreatment with sodium selenite reduced the hyperglycemia mediated enhancement of ferroptosis. Furthermore, we observed that pretreatment with sodium selenite increased YAP and TAZ levels in the cytoplasm while decreasing YAP and TAZ levels in the nucleus. The Hippo pathway inhibitor XMU-MP-1 eliminated the inhibitory effect of sodium selenite on ferroptosis. The findings suggest that pretreatment with sodium selenite can regulate ferroptosis by activating the Hippo pathway, and minimize hyperglycemia-mediated exacerbation of cerebral I/R injury.

Sirtuins: Promising Therapeutic Targets to Treat Ischemic Stroke

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

Role of NAD+ and FAD in Ischemic Stroke Pathophysiology: An Epigenetic Nexus and Expanding Therapeutic Repertoire

The redox coenzymes viz., oxidized β-nicotinamide adenine dinucleotide (NAD⁺) and flavin adenine dinucleotide (FAD) by way of generation of optimal reducing power and cellular energy currency (ATP), control a staggering array of metabolic reactions. The prominent cellular contenders for NAD⁺ utilization, inter alia, are sirtuins (SIRTs) and poly(ADP-ribose) polymerase (PARP-1), which have been significantly implicated in ischemic stroke (IS) pathogenesis. NAD⁺ and FAD are also two crucial epigenetic enzyme-required metabolites mediating histone deacetylation and poly(ADP-ribosyl)ation through SIRTs and PARP-1 respectively, and demethylation through FAD-mediated lysine specific demethylase activity. These enzymes and post-translational modifications impinge on the components of neurovascular unit, primarily neurons, and elicit diverse functional upshots in an ischemic brain. These could be circumstantially linked with attendant cognitive deficits and behavioral outcomes in post-stroke epoch. Parsing out the contribution of NAD⁺/FAD-synthesizing and utilizing enzymes towards epigenetic remodeling in IS setting, together with their cognitive and behavioral associations, combined with possible therapeutic implications will form the crux of this review.

The relationship between diabetes mellitus and attention deficit hyperactivity disorder: A systematic review and meta-analysis

Background

This study aims to investigate the prevalence estimate of diabetes mellitus (DM) among people with attention deficit hyperactivity disorder (ADHD) as well as the prevalence of ADHD among those with DM. In addition, the impact of ADHD on glycemic control in patients with DM was also assessed using a systematic review and meta-analysis of currently available published data.

Materials and methods

The PubMed, Embase, Web of Science, and PsycInfo databases were searched for potential studies. Two reviewers independently selected studies according to the inclusion and exclusion criteria. All pooled analyses were conducted using the random-effects models on Review Manager 5.3.

Results

Seventeen observational studies were included. The pooled results showed an increase in the prevalence of DM among patients with ADHD versus those without ADHD [type 1 DM OR: 1.37 (95% CI: 1.17-1.61); type 2 DM OR: 2.05 (95% CI: 1.37-3.07)]. There was an overall 35% increase in the prevalence of ADHD among patients with type 1 DM [OR: 1.35 (95% CI: 1.08-1.73)]. Children with type 1 DM and ADHD had higher levels of hemoglobin A1c [standardized mean of differences: 0.67 (95% CI: 0.48-0.86)], and prevalence of hypoglycemic and ketoacidosis index compared with those without ADHD.

Conclusion

Our study revealed the bidirectional associations between ADHD and DM. Patients with ADHD and type 1 DM comorbidities were more likely to have poorer diabetes control. More studies are needed to confirm this association and elucidate the underlying mechanism.

Glucose to Platelet Ratio: A Potential Predictor of Hemorrhagic Transformation in Patients with Acute Ischemic Stroke

Glucose and platelet are two easily obtained clinical indicators; the present research aimed to demonstrate their association with hemorrhagic transformation (HT) in acute ischemic stroke (AIS) patients without thrombolytic or thrombectomy therapy. This was a single-center retrospective study. Patients who were diagnosed with HT after AIS were included in the HT group. Meanwhile, using the propensity score matching (PSM) approach, with a ratio of 1:2, matched patients without HT were included in the non-HT group. Serum G/P levels were measured on the first morning after admission (at least eight hours after the last meal). Characteristics were compared between the two groups. Multivariate logistic regression was used to determine the independent relationship between G/P and HT after AIS, with G/P being divided into quartiles. From January 2013 to March 2022, we consecutively included 643 AIS patients with HT (426/643 [66.25%] with HI and 217/643 [33.75%] with PH), and 1282 AIS patients without HT, at the First Affiliated Hospital of Wenzhou Medical University. The HT group had higher G/P levels than the non-HT group (0.04 ± 0.02 vs. 0.03 ± 0.02, p < 0.001). However, there was no difference in G/P levels between HI and PH subgroups (0.04 ± 0.02 vs. 0.04 ± 0.02, p > 0.05). Moreover, the G/P levels were divided into quartiles (Q1 ≤ 0.022; Q2 = 0.023−0.028; Q3 = 0.029−0.039; Q4 ≥ 0.040), with Q1 being settled as the reference layer. After controlling the confounders, multivariate regression analyses showed that the Q4 layer (Q4: G/P ≥ 0.040) was independently associated with elevated HT risk (odds ratio [OR] = 1.85, 95% CI = 1.31−2.63, p < 0.001). G/P levels on admission were independently associated with HT risk in AIS patients. In clinical practice, adequate attention should be paid to AIS patients with elevated G/P levels (G/P ≥ 0.040).

The application and perspective of hyperbaric oxygen therapy in acute ischemic stroke: From the bench to a starter?

Stroke has become a significant cause of death and disability globally. Along with the transition of the world's aging population, the incidence of acute ischemic stroke is increasing year by year. Even with effective treatment modalities, patients are not guaranteed to have a good prognosis. The treatment model combining intravenous thrombolysis/endovascular therapy and neuroprotection is gradually being recognized. After the clinical translation of pharmacological neuroprotective agents failed, non-pharmacological physical neuroprotective agents have rekindled hope. We performed a literature review using the National Center for Biotechnology Information (NCBI) PubMed database for studies that focused on the application of hyperbaric oxygen therapy in acute ischemic stroke. In this review, we present the history and mechanisms of hyperbaric oxygen therapy, focusing on the current status, outcomes, current challenges, perspective, safety, and complications of the application of hyperbaric oxygen in animal experiments and human clinical trials. Hyperbaric oxygen therapy, a non-pharmacological treatment, can improve the oxygenation level at the ischemic lesions in increased dissolved oxygen and oxygen diffusion radius to achieve salvage of neurological function, giving a new meaning to acute ischemic stroke.

Hyperbaric oxygen therapy for healthy aging: From mechanisms to therapeutics

Hyperbaric oxygen therapy (HBOT), a technique through which 100% oxygen is provided at a pressure higher than 1 atm absolute (ATA), has become a well-established treatment modality for multiple conditions. The noninvasive nature, favorable safety profile, and common clinical application of HBOT make it a competitive candidate for several new indications, one of them being aging and age-related diseases. In fact, despite the conventional wisdom that excessive oxygen accelerates aging, appropriate HBOT protocols without exceeding the toxicity threshold have shown great promise in therapies against aging. For one thing, an extensive body of basic research has expanded our mechanistic understanding of HBOT. Interestingly, the therapeutic targets of HBOT overlap considerably with those of aging and age-related diseases. For another, pre-clinical and small-scale clinical investigations have provided validated information on the efficacy of HBOT against aging from various aspects. However, a generally applicable protocol for HBOT to be utilized in therapies against aging needs to be defined as a subsequent step. It is high time to look back and summarize the recent advances concerning biological mechanisms and therapeutic implications of HBOT in promoting healthy aging and shed light on prospective directions. Here we provide the first comprehensive overview of HBOT in the field of aging and geriatric research, which allows the scientific community to be aware of the emerging tendency and move beyond conventional wisdom to scientific findings of translational value.

Nicotinamide Mononucleotide Adenylyltransferase 1 Regulates Cerebral Ischemia-Induced Blood-Brain Barrier Disruption Through NAD+/SIRT1 Signaling Pathway

The molecular mechanisms of blood-brain barrier (BBB) disruption in the early stage after ischemic stroke are poorly understood. In the present study, we investigated the potential role of nicotinamide mononucleotide adenylyltransferase 1 (NMNAT1) in ischemia-induced BBB damage using an animal middle cerebral artery occlusion (MCAO) model of ischemic stroke. Recombinant human NMNAT1 (rh-NMNAT1) was administered intranasally and Sirtuin 1 (SIRT1) siRNA was administered by intracerebroventricular injection. Our results indicate that rh-NMNAT1 reduced infarct volume, improved functional outcome, and decreased BBB permeability in mice after ischemic stroke. Furthermore, rh-NMNAT1 prevented the loss of tight junction proteins (occludin and claudin-5) and reduced cell apoptosis in ischemic microvessels. NMNAT1-mediated BBB permeability was correlated with the elevation of nicotinamide adenine dinucleotide (NAD⁺)/NADH ratio and SIRT1 level in brain microvascular endothelial cells. In addition, rh-NMNAT1 treatment significantly decreased the levels of acetylated nuclear factor-κB, acetylated p53, and matrix metalloproteinase-9 in ischemic microvessels. Moreover, the protective effects of rh-NMNAT1 could be reversed by SIRT1 siRNA. In conclusion, these findings indicate that rh-NMNAT1 protects BBB integrity after cerebral ischemia via the NAD⁺/SIRT1 signaling pathway in brain microvascular endothelial cells. NMNAT1 may be a novel potential therapeutic target for reducing BBB disruption after ischemic stroke.

Relationships Among Gut Microbiota, Ischemic Stroke and Its Risk Factors: Based on Research Evidence

Stroke is a highly lethal disease and disabling illness while ischemic stroke accounts for the majority of stroke. It has been found that inflammation plays a key role in the initiation and progression of stroke, and atherosclerotic plaque rupture is considered to be the leading cause of ischemic stroke. Furthermore, chronic inflammatory diseases, such as obesity, type 2 diabetes mellitus (T2DM) and hypertension, are also considered as the high-risk factors for stroke. Recently, the topic on how gut microbiota affects human health has aroused great concern. The initiation and progression of ischemic stroke has been found to have close relation with gut microbiota dysbiosis. Hence, this manuscript briefly summarizes the roles of gut microbiota in ischemic stroke and its related risk factors, and the practicability of preventing and alleviating ischemic stroke by reconstructing gut microbiota.

Bone marrow mesenchymal stem cells-derived exosomal microRNA-124-3p attenuates hypoxic-ischemic brain damage through depressing tumor necrosis factor receptor associated factor 6 in newborn rats

Mesenchymal stem cells (MSCs)-derived exosomes (Exo) are beneficial in the use of brain damages. Restrictively, the mechanism of Exo expressing miR-124-3p in hypoxic-ischemic brain damage (HIBD) is not completely comprehended. Thereupon, this work was put forward to reveal the action of bone marrow MSCs-derived Exo (BMSCs-Exo) expressing miR-124-3p in the illness. BMSCs were isolated and transfected with miR-124-3p agomir. Then, BMSCs-Exo were extracted and identified. The newborn HIBD rats were injected with miR-124-3p-modified BMSCs-Exo or tumor necrosis factor receptor associated factor 6 (TRAF6)-related vectors. Next, neurological functions, neuron pathological and structural damages, oxidative stress and neuronal apoptosis were observed. miR-124-3p and TRAF6 expression was tested, along with their targeting relationship. miR-124-3p was down-regulated, and TRAF6 was up-regulated in newborn HIBD rats. miR-124-3p targeted TRAF6. BMSCs-Exo improved neurological functions, alleviated neuron pathological and structural damages, suppressed oxidative stress and reduced neuronal apoptosis in newborn HIBD rats, whereas BMSCs-Exo-mediated effects were enhanced by restoring miR-124-3p. Silencing TRAF6 attenuated HIBD in newborn rats, but overexpression of TRAF6 reversed the protective role of miR-124-3p-overexpressing BMSCs-Exo. This work makes it comprehensive that up-regulated exosomal miR-124-3p ameliorates HIBD in newborn rats by targeting TRAF6, which replenishes the potential agents for curing HIBD.

microRNA-455-5p alleviates neuroinflammation in cerebral ischemia/reperfusion injury

Neuroinflammation is a major pathophysiological factor that results in the development of brain injury after cerebral ischemia/reperfusion. Downregulation of microRNA (miR)-455-5p after ischemic stroke has been considered a potential biomarker and therapeutic target for neuronal injury after ischemia. However, the role of miR-455-5p in the post-ischemia/reperfusion inflammatory response and the underlying mechanism have not been evaluated. In this study, mouse models of cerebral ischemia/reperfusion injury were established by transient occlusion of the middle cerebral artery for 1 hour followed by reperfusion. Agomir-455-5p, antagomir-455-5p, and their negative controls were injected intracerebroventricularly 2 hours before or 0 and 1 hour after middle cerebral artery occlusion (MCAO). The results showed that cerebral ischemia/reperfusion decreased miR-455-5p expression in the brain tissue and the peripheral blood. Agomir-455-5p pretreatment increased miR-455-5p expression in the brain tissue, reduced the cerebral infarct volume, and improved neurological function. Furthermore, primary cultured microglia were exposed to oxygen-glucose deprivation for 3 hours followed by 21 hours of reoxygenation to mimic cerebral ischemia/reperfusion. miR-455-5p reduced C-C chemokine receptor type 5 mRNA and protein levels, inhibited microglia activation, and reduced the production of the inflammatory factors tumor necrosis factor-α and interleukin-1β. These results suggest that miR-455-5p is a potential biomarker and therapeutic target for the treatment of cerebral ischemia/reperfusion injury and that it alleviates cerebral ischemia/reperfusion injury by inhibiting C-C chemokine receptor type 5 expression and reducing the neuroinflammatory response.

Effects and mechanisms of CTRP3 overexpression in secondary brain injury following intracerebral hemorrhage in rats

C1q/TNF-related protein-3 (CTRP3) is a novel adipokine that serves an important role in oxidative stress, anti-apoptosis, anti-inflammation and immune regulation. The aim of the present study was to investigate the protective role of CTRP3 against intracerebral hemorrhage (ICH)-induced brain injury. A model of autologous arterial blood-induced ICH was constructed in rats. Intracerebral infusion of a lentivirus carrying the CTRP3 gene was used to induce CTRP3 overexpression in the brain. The effects and mechanisms of CTRP3 overexpression on brain injury were investigated by detecting brain edema, blood-brain barrier (BBB) integrity, neurological function and inflammatory-associated factors 3 days after ICH. The present results demonstrated that CTRP3 overexpression ameliorated ICH-induced neurological dysfunction, decreased brain edema, maintained BBB integrity and attenuated inflammation. The protective effect of CTRP3 overexpression was associated with increased activation of silent information regulator 1 (SIRT1). In conclusion, the present study demonstrated that CTRP3 overexpression protected against ICH-induced brain injury in rats, potentially via activating the SIRT1 signaling pathway.

Hyperbaric Oxygen Treatment-From Mechanisms to Cognitive Improvement

Hyperbaric oxygen treatment (HBOT)—the medical use of oxygen at environmental pressure greater than one atmosphere absolute—is a very effective therapy for several approved clinical situations, such as carbon monoxide intoxication, incurable diabetes or radiation-injury wounds, and smoke inhalation. In recent years, it has also been used to improve cognition, neuro-wellness, and quality of life following brain trauma and stroke. This opens new avenues for the elderly, including the treatment of neurological and neurodegenerative diseases and improvement of cognition and brain metabolism in cases of mild cognitive impairment. Alongside its integration into clinics, basic research studies have elucidated HBOT’s mechanisms of action and its effects on cellular processes, transcription factors, mitochondrial function, oxidative stress, and inflammation. Therefore, HBOT is becoming a major player in 21st century research and clinical treatments. The following review will discuss the basic mechanisms of HBOT, and its effects on cellular processes, cognition, and brain disorders.

Integrative Role of Hyperbaric Oxygen Therapy on Healthspan, Age-Related Vascular Cognitive Impairment, and Dementia

Growing life expectancy will contribute to the on-going shift towards a world population increasingly comprised of elderly individuals. This demographic shift is associated with a rising prevalence of age-related diseases, among all age-related pathologies it has become crucial to understand the age-associated cognitive changes that remain a major risk factor for the development of vascular cognitive impairment and dementia (VCID). Furthermore, age-related Alzheimer's disease and other neurogenerative diseases with vascular etiology are the most prominent contributing factors for the loss of cognitive function observed in aging. Hyperbaric Oxygen Therapy (HBOT) achieves physiologic effects by increasing oxygen tension (PO2), raising oxygen tissue levels, decreasing intracranial pressure and relieving cerebral edema. Many of the beneficial effects of HBOT exert their protective effects at the level of the microcirculation. Furthermore, the microcirculation's exquisite pervasive presence across every tissue in the body, renders it uniquely able to influence the local environment of most tissues and organs, including the brain. As such, treatments aimed at restoring aging-induced functional and structural alterations of the cerebral microcirculation may potentially contribute to the amelioration of a range of age-related pathologies including vascular cognitive impairment, Alzheimer's disease, and vascular dementias. Despite the presented evidence, the efficacy and safety of HBOT for the treatment of age-related vascular cognitive impairment and dementia remains understudied. The present review aims to examine the existing evidence indicative of a potential therapeutic role for HBOT-induced hyperoxia against age-related cerebromicrovascular pathologies contributing to cognitive impairment, dementia and decreased healthspan in the elderly.

Emerging role of PARP-1 and PARthanatos in ischemic stroke

Cell death is a key feature of neurological diseases, including stroke and neurodegenerative disorders. Studies in a variety of ischemic/hypoxic mouse models demonstrate that poly(ADP-ribose) polymerase 1 (PARP-1)-dependent cell death, also named PARthanatos, plays a pivotal role in ischemic neuronal cell death and disease progress. PARthanatos has its unique triggers, processors, and executors that convey a highly orchestrated and programmed signaling cascade. In addition to its role in gene transcription, DNA damage repair, and energy homeostasis through PARylation of its various targets, PARP-1 activation in neuron and glia attributes to brain damage following ischemia/reperfusion. Pharmacological inhibition or genetic deletion of PARP-1 reduces infarct volume, eliminates inflammation, and improves recovery of neurological functions in stroke. Here, we reviewed the role of PARP-1 and PARthanatos in stroke and their therapeutic potential.

Blood-brain barrier dysfunction in ischemic stroke and diabetes: the underlying link, mechanisms and future possible therapeutic targets

Ischemic stroke caused by occlusion of cerebral artery is responsible for the majority of stroke that increases the morbidity and mortality worldwide. Diabetes mellitus (DM) is a crucial risk factor for ischemic stroke. Prolonged DM causes various microvascular and macrovascular changes, and blood-brain barrier (BBB) permeability that facilitates inflammatory response following stroke. In the acute phase following stroke, BBB disruption has been considered the initial step that induces neurological deficit and functional disabilities. Stroke outcomes are significantly worse among DM. In this article, we review stroke with diabetes-induce BBB damage, as well as underlying mechanism and possible therapeutic targets for stroke with diabetes.

Melatonin protects against focal cerebral ischemia-reperfusion injury in diabetic mice by ameliorating mitochondrial impairments: involvement of the Akt-SIRT3-SOD2 signaling pathway

Diabetic patients are more vulnerable to cerebral ischemia-reperfusion (CIR) injury and have a worse prognosis and higher mortality after ischemic stroke than non-diabetic counterparts. Melatonin can exert neuroprotective effects against CIR injury in nondiabetic animal models. However, its effects on diabetic CIR injury and the underlying mechanisms remain unclarified. Herein, we found that melatonin administration improved neurological deficit, cerebral infarct volume, brain edema, and cell viability, reduced mitochondrial swelling, reactive oxygen species generation, and cytoplasmic cytochrome C release, and increased mitochondrial antioxidant enzymes activities, adenosine triphosphate production, and mitochondrial membrane potential in both streptozotocin-induced diabetic mice and high glucose-treated HT22 cells. Importantly, melatonin also activated protein kinase B (Akt) and sirtuin 3 (SIRT3)/superoxide dismutase 2 (SOD2) signaling and upregulated mitochondrial biogenesis-related transcription factors. However, these effects were largely attenuated by LY294002 (a specific Akt signaling blocker) administration. Additionally, 3-TYP (a selective SIRT3 inhibitor) and SIRT3 siRNA inhibited the above protective effects of melatonin as well as the upregulation of SIRT3 and the decrease of SOD2 acetylation but did not affect the p-Akt/Akt ratio. Overall, we demonstrate that melatonin can alleviate CIR injury in diabetic mice by activating Akt-SIRT3-SOD2 signaling and subsequently improving mitochondrial damage.

Damage to the blood‑brain barrier and activation of neuroinflammation by focal cerebral ischemia under hyperglycemic condition

Hyperglycemia aggravates brain damage caused by cerebral ischemia/reperfusion (I/R) and increases the permeability of the blood‑brain barrier (BBB). However, there are relatively few studies on morphological changes of the BBB. The present study aimed to investigate the effect of hyperglycemia on BBB morphological changes following cerebral I/R injury. Streptozotocin‑induced hyperglycemic and citrate‑buffered saline‑injected normoglycemic rats were subjected to 30 min middle cerebral artery occlusion. Neurological deficits were evaluated. Brain infarct volume was assessed by 2,3,5‑triphenyltetrazolium chloride staining and BBB integrity was evaluated by Evans blue and IgG extravasation following 24 h reperfusion. Changes in tight junctions (TJ) and basement membrane (BM) proteins (claudin, occludin and zonula occludens‑1) were examined using immunohistochemistry and western blotting. Astrocytes, microglial cells and neutrophils were labeled with specific antibodies for immunohistochemistry after 1, 3 and 7 days of reperfusion. Hyperglycemia increased extravasations of Evan's blue and IgG and aggravated damage to TJ and BM proteins following I/R injury. Furthermore, hyperglycemia suppressed astrocyte activation and damaged astrocytic endfeet surrounding cerebral blood vessels following I/R. Hyperglycemia inhibited microglia activation and proliferation and increased neutrophil infiltration in the brain. It was concluded that hyperglycemia‑induced BBB leakage following I/R might be caused by damage to TJ and BM proteins and astrocytic endfeet. Furthermore, suppression of microglial cells and increased neutrophil infiltration to the brain may contribute to the detrimental effects of pre‑ischemic hyperglycemia on the outcome of cerebral ischemic stroke.

Xiao-Xu-Ming decoction prevented hemorrhagic transformation induced by acute hyperglycemia through inhibiting AGE-RAGE-mediated neuroinflammation

Stroke is one of the leading causes of death worldwide. Hemorrhagic transformation (HT) is a common serious complication of ischemic stroke (IS) and is related to poor prognosis. Hyperglycemia after stroke is associated with the occurrence of HT and seriously affects the clinical treatment of stroke. Our previous experiments demonstrated that the Xiao-Xu-Ming decoction effective components group (XXMD), which is a Chinese medicine formula reconstituted by active ingredients, has multiple pharmacological effects in the treatment of IS. However, the effects of XXMD on HT after IS remain unclear. Thus, we investigated the preventive effects of XXMD on hyperglycemia-induced HT and further explored the underlying mechanism. Acute hyperglycemia combined with the electrocoagulation cerebral ischemia model was used to establish the HT model. XXMD (37.5, 75, 150 mg/kg/d) was given by gavage for 5 days. Network pharmacology was used to predict potential targets and pathways of XXMD in HT occurrence, and further studies confirmed the related targets. The results showed that hyperglycemia aggravated neurological deficits and blood-brain barrier (BBB) disruption, leading to intracerebral hemorrhage. Pretreatment with XXMD improved neurological function and BBB integrity and inhibited HT occurrence. Network pharmacology revealed that AGE-RAGE-mediated neuroinflammation may be associated with hyperglycemia-induced HT. Further studies confirmed that hyperglycemia activated the AGE-RAGE signaling pathway, increased the expression of HMGB1, TLR4 and p-p65, and induced the release of inflammatory factors and neutrophil infiltration, leading to HT. XXMD could inhibit AGE-RAGE-mediated neuroinflammation. These findings indicated that pretreatment with XXMD alleviated hyperglycemia-induced HT, which may be associated with the inhibition of AGE-RAGE-mediated neuroinflammation. Therefore, XXMD may be a potential therapeutic drug for HT.

Rejuvenation Through Oxygen, More or Less

Modest modulation of oxygen intake, either by inducing mild intermittent hypoxia or hyperoxia appears to induce modest rejuvenative changes in mammals, in part, by activating key regulator hypoxia-induced factor 1a (HIF-1a). Interestingly both lower oxygen and transient higher oxygen levels induce this hypoxia regulator. Hyperbaric oxygen induces HIF-1a by the hyperoxic-hypoxic paradox that results from an overinduction of protective factors under intermittent hyperoxic conditions, leading to a state somewhat similar to that induced by hypoxia. A key difference being that SIRT1 is induced by hyperoxia, whereas it is reduced during hypoxia by the activity of HIF-1a. In a recent report, a small clinical trial employing 60 sessions of intermittent hyperbaric oxygen therapy (HBOT) studying old humans resulted in increased mean telomere length of immune cells including B cells, natural killer cells, T helper, and cytotoxic T lymphocytes. Moreover, there was a reduction in CD28^null senescent T helper and cytotoxic T cells. In a parallel report, HBOT has been reported to enhance cognition in older adults, especially attention and information processing speed through increased cerebral blood flow (CBF) in brain regions where CBF tends to decline with age. The durability of these beneficial changes is yet to be determined. These preliminary results require follow-up, including more extensive characterization of changes in aging-associated biomarkers. An interesting avenue of potential work is to elucidate potential connections between hypoxia and epigenetics, especially the induction of the master pluripotent regulatory factors, which when expressed transiently have been reported to ameliorate some aging biomarkers and pathologies.

TGR5 activation attenuates neuroinflammation via Pellino3 inhibition of caspase-8/NLRP3 after middle cerebral artery occlusion in rats

BACKGROUND

Nucleotide-binding oligomerization domain-like receptor pyrin domain-containing protein 3 (NLRP3) plays an important role in mediating inflammatory responses during ischemic stroke. Bile acid receptor Takeda-G-protein-receptor-5 (TGR5) has been identified as an important component in regulating brain inflammatory responses. In this study, we investigated the mechanism of TGR5 in alleviating neuroinflammation after middle cerebral artery occlusion (MCAO).

METHODS

Sprague-Dawley rats were subjected to MCAO and TGR5 agonist INT777 was administered intranasally 1 h after MCAO. Small interfering RNAs (siRNA) targeting TGR5 and Pellino3 were administered through intracerebroventricular injection 48 h before MCAO. Infarct volumes and neurologic scores were evaluated, and ELISA, flow cytometry, immunofluorescence staining, immunoblotting, and co-immunoprecipitation were used for the evaluations.

RESULTS

Endogenous TGR5 and Pellino3 levels increased after MCAO. TGR5 activation by INT777 significantly decreased pro-inflammatory cytokine, cleaved caspase-8, and NLRP3 levels, thereby reducing brain infarctions; both short- and long-term neurobehavioral assessments showed improvements. Ischemic damage induced the interaction of TGR5 with Pellino3. Knockdown of either TGR5 or Pellino3 increased the accumulation of cleaved caspase-8 and NLRP3, aggravated cerebral impairments, and abolished the anti-inflammatory effects of INT777 after MCAO.

CONCLUSIONS

TGR5 activation attenuated brain injury by inhibiting neuroinflammation after MCAO, which could be mediated by Pellino3 inhibition of caspase-8/NLRP3.

Sodium butyrate attenuated neuronal apoptosis via GPR41/Gβγ/PI3K/Akt pathway after MCAO in rats

Sodium butyrate, a short-chain fatty acid, is predominantly produced by gut microbiota fermentation of dietary fiber and serves as an important neuromodulator in the central nervous system. Recent experimental evidence has suggested that sodium butyrate may be an endogenous ligand for two orphan G protein-coupled receptors, GPR41 and GP43, which regulate apoptosis and inflammation in ischemia-related pathologies, including stroke. In the present study, we evaluated the potential efficacy and mechanism of action of short-chain fatty acids in a rat model of middle cerebral artery occlusion (MCAO). Fatty acids were intranasally administered 1 h post MCAO. Short-chain fatty acids, especially sodium butyrate, reduced infarct volume and improved neurological function at 24 and 72 h after MCAO. At 24 h, the effects of MCAO, increased apoptosis, were ameliorated after treatment with sodium butyrate, which increased the expressions of GPR41, PI3K and phosphorylated Akt. To confirm these mechanistic links and characterize the GPR active subunit, PC12 cells were subjected to oxygen-glucose deprivation and reoxygenation, and pharmacological and siRNA interventions were used to reverse efficacy. Taken together, intranasal administration of sodium butyrate activated PI3K/Akt via GPR41/Gβγ and attenuated neuronal apoptosis after MCAO.

A review on the neuroprotective effects of hyperbaric oxygen therapy

Hyperbaric oxygen therapy, intermittent breathing of 100% oxygen at a pressure upper than sea level, has been shown to be some of the neuroprotective effects and used therapeutically in a wide range of neurological disorders. This review summarizes current knowledge about the neuroprotective effects of hyperbaric oxygen therapy with their molecular mechanisms in different models of neurological disorders.

Ultrastructural studies of the neurovascular unit reveal enhanced endothelial transcytosis in hyperglycemia‐enhanced hemorrhagic transformation after stroke

Aims

Pre‐existing hyperglycemia (HG) aggravates the breakdown of blood–brain barrier (BBB) and increases the risk of hemorrhagic transformation (HT) after acute ischemic stroke in both animal models and patients. To date, HG‐induced ultrastructural changes of brain microvascular endothelial cells (BMECs) and the mechanisms underlying HG‐enhanced HT after ischemic stroke are poorly understood.

Methods

We used a mouse model of mild brain ischemia/reperfusion to investigate HG‐induced ultrastructural changes of BMECs that contribute to the impairment of BBB integrity after stroke. Adult male mice received systemic glucose administration 15 min before middle cerebral artery occlusion (MCAO) for 20 min. Ultrastructural characteristics of BMECs were evaluated using two‐dimensional and three‐dimensional electron microscopy and quantitatively analyzed.

Results

Mice with acute HG had exacerbated BBB disruption and larger brain infarcts compared to mice with normoglycemia (NG) after MCAO and 4 h of reperfusion, as assessed by brain extravasation of the Evans blue dye and microtubule‐associated protein 2 immunostaining. Electron microscopy further revealed that HG mice had more endothelial vesicles in the striatal neurovascular unit than NG mice, which may account for their deterioration of BBB impairment. In contrast with enhanced endothelial transcytosis, paracellular tight junction ultrastructure was not disrupted after this mild ischemia/reperfusion insult or altered upon HG. Consistent with the observed increase of endothelial vesicles, transcytosis‐related proteins caveolin‐1, clathrin, and hypoxia‐inducible factor (HIF)‐1α were upregulated by HG after MCAO and reperfusion.

Conclusion

Our study provides solid structural evidence to understand the role of endothelial transcytosis in HG‐elicited BBB hyperpermeability. Enhanced transcytosis occurs prior to the physical breakdown of BMECs and is a promising therapeutic target to preserve BBB integrity.

Functional MRI (fMRI) Evaluation of Hyperbaric Oxygen Therapy (HBOT) Efficacy in Chronic Cerebral Stroke: A Small Retrospective Consecutive Case Series

Topics: Functional Magnetic Resonance Imaging (fMRI) evaluation of HyberBaric Oxygen Therapy (HBOT) effects on chronic cerebral stroke Patients (Pts). Introduction: Our aim was to evaluate with fMRI, in a 3 Tesla system, the functional effects of HBOT on the Central Nervous System (CNS) in four Pts with established ischaemic and haemorrhagic cerebral strokes (2 Pts each). To our knowledge, no author used this Magnetic Resonance (MR) technique for this purpose, till now. Methods: All four Pts underwent a fMRI study before and after 40 HBOT sessions, with a time window of a few days. They carried out two language (text listening, silent word-verb generation) and two motor (hand and foot movements) tasks (30 s On-Off block paradigms). Results: After HBOT, all Pts reported a clinical improvement, mostly concerning language fluency and motor paresis. fMRI analysis demonstrated an increase in both the extent and the statistical significance of most of the examined eloquent areas. Conclusions: These changes were consistent with the clinical improvement in all Pts, suggesting a possible role of fMRI in revealing neuronal functional correlates of neuronal plasticity and HBOT-related neoangiogenesis. Although only four Pts were examined, fMRI proved to be a sensitive, non-invasive and reliable modality for monitoring neuronal functional changes before and after HBOT.

Notoginseng Leaf Triterpenes Ameliorates OGD/R-Induced Neuronal Injury via SIRT1/2/3-Foxo3a-MnSOD/PGC-1α Signaling Pathways Mediated by the NAMPT-NAD Pathway

Background

Cerebral ischemic stroke (CIS) is a common cerebrovascular disease whose main risks include necrosis, apoptosis, and cerebral infarction. But few therapeutic advances and prominent drugs seem to be of value for ischemic stroke in the clinic yet. In the previous study, notoginseng leaf triterpenes (PNGL) from Panax notoginseng stem and leaf have been confirmed to have neuroprotective effects against mitochondrial damages caused by cerebral ischemia in vivo. However, the potential mechanisms of mitochondrial protection have not been fully elaborated yet.

Methods

The oxygen and glucose deprivation and reperfusion (OGD/R)-induced SH-SY5Y cells were adopted to explore the neuroprotective effects and the potential mechanisms of PNGL in vitro. Cellular cytotoxicity was measured by MTT, viable mitochondrial staining, and antioxidant marker detection in vitro.Mitochondrial functions were analyzed by ATP content measurement, MMP determination, ROS, NAD, and NADH kit in vitro. And the inhibitor FK866 was adopted to verify the regulation of PNGL on the target NAMPT and its key downstream.

Results

In OGD/R models, treatment with PNGL strikingly alleviated ischemia injury, obviously preserved redox balance and excessive oxidative stress, inhibited mitochondrial damage, markedly alleviated energy metabolism dysfunction, improved neuronal mitochondrial functions, obviously reduced neuronal loss and apoptosis in vitro, and thus notedly raised neuronal survival under ischemia and hypoxia. Meanwhile, PNGL markedly increased the expression of nicotinamide phosphoribosyltransferase (NAMPT) in the ischemic regions and OGD/R-induced SH-SY5Y cells and regulated the downstream SIRT1/2-Foxo3a and SIRT1/3-MnSOD/PGC-1α pathways. And FK866 further verified that the protective effects of PNGL might be mediated by the NAMPT in vitro.

Conclusions

The mitochondrial protective effects of PNGL are, at least partly, mediated via the NAMPT-NAD+ and its downstream SIRT1/2/3-Foxo3a-MnSOD/PGC-1α signaling pathways. PNGL, as a new drug candidate, has a pivotal role in mitochondrial homeostasis and energy metabolism therapy via NAMPT against OGD-induced SH-SY5Y cell injury.

RiPerC Attenuates Cerebral Ischemia Injury through Regulation of miR-98/PIK3IP1/PI3K/AKT Signaling Pathway

Background

Cerebral ischemic stroke is a refractory disease which seriously endangers human health. Remote ischemic perconditioning (RiPerC) by which the sublethal ischemic stimulus is administered during the ischemic event is beneficial after an acute stroke. However, the regulatory mechanism of RiPerC that relieves cerebral ischemic injury is still not completely clear.

Methods

In the present study, we investigated the regulatory mechanism of RiPerC in a rat model of ischemia induced by the middle cerebral artery occlusion (MCAO). Forty-eight adult male Sprague-Dawley (SD) rats were injected intracerebroventricularly with miR-98 agomir, miR-98 antagomir, or their negative controls (agomir-NC, antagomir-NC) 2 h before MCAO or MCAO+RiPerC followed by animal behavior tests and infraction volume measurement at 24 h after MCAO. The expression of miR-98, PIK3IP1, and tight junction proteins in rat hippocampus and cerebral cortex tissues was detected by quantitative polymerase chain reaction (qPCR) and Western blot (WB). Enzyme-linked immunosorbent assay (ELISA) was used to assess the IL-1β, IL-6, and TNF-α levels in the rat serum.

Results

The results showed that in MCAO group, the expression of PIK3IP1 was upregulated, but decreased after RiPerC treatment. Then, we found that PIK3IP1 was a potential target of miR-98. Treatment with miR-98 agomir decreased the infraction volume, reduced brain edema, and improved neurological functions compared to control rats. But treating with miR-98 antagomir in RiPerC group, the protective effect on cerebral ischemia injury was canceled.

Conclusion

Our finding indicated that RiPerC inhibited the MCAO-induced expression of PIK3IP1 through upregulated miR-98, thereby reducing the apoptosis induced by PIK3IP1 through the PI3K/AKT signaling pathway, thus reducing the cerebral ischemia-reperfusion injury.

Executive Function and Diabetes: A Clinical Neuropsychology Perspective

Objective

Diabetes is a global public health concern. Management of diabetes depends on successful implementation of strategies to alleviate decline in executive functions (EFs), a characteristic of diabetes progression. In this review, we describe recent research on the relationship between diabetes and EF, summarize the existing evidence, and put forward future research directions and applications.

Methods

Herein, we provide an overview of recent studies, to elucidate the relationship between DM and EF. We identified new screening objectives, management tools, and intervention targets for diabetes management. We also discuss the implications for clinical practice.

Results

In both types 1 and 2 diabetes mellitus (DM), hyperglycemia substantially impairs EF in people of all age groups and ethnicities. Hypoglycemia can similarly impair EF. Interestingly, a decline in EF contributes to DM progression. Glucose dysregulation and EF decline exacerbate each other in a vicious cycle: poor blood glucose control, impaired EF, diabetes management task failure, then back to poor blood glucose control. Many pathophysiological indexes (e.g., obesity, metabolic index, inflammatory and immune factors), neuropsychological indexes (e.g., compliance, eating habits, physical exercise, sleep, and depression), and genetic factors are changed by this pathological interaction between DM and EF. These changes can provide insight into the pathophysiological mechanisms of diabetes-related EF decline.

Conclusion

Further studies, including large-scale prospective and randomized controlled trials, are needed to elucidate the mechanism of the interaction between diabetes and EF and to develop novel strategies for breaking this cycle.

An Extra Breath of Fresh Air: Hyperbaric Oxygenation as a Stroke Therapeutic

Stroke serves as a life-threatening disease and continues to face many challenges in the development of safe and effective therapeutic options. The use of hyperbaric oxygen therapy (HBOT) demonstrates pre-clinical effectiveness for the treatment of acute ischemic stroke and reports reductions in oxidative stress, inflammation, and neural apoptosis. These pathophysiological benefits contribute to improved functional recovery. Current pre-clinical and clinical studies are testing the applications of HBOT for stroke neuroprotection, including its use as a preconditioning regimen. Mild oxidative stress may be able to prime the brain to tolerate full extensive oxidative stress that occurs during a stroke, and HBOT preconditioning has displayed efficacy in establishing such ischemic tolerance. In this review, evidence on the use of HBOT following an ischemic stroke is examined, and the potential for HBOT preconditioning as a neuroprotective strategy. Additionally, HBOT as a stem cell preconditioning is also discussed as a promising strategy, thus maximizing the use of HBOT for ischemic stroke.

Molecular and Therapeutic Aspects of Hyperbaric Oxygen Therapy in Neurological Conditions

In hyperbaric oxygen therapy (HBOT), the subject is placed in a chamber containing 100% oxygen gas at a pressure of more than one atmosphere absolute. This treatment is used to hasten tissue recovery and improve its physiological aspects, by providing an increased supply of oxygen to the damaged tissue. In this review, we discuss the consequences of hypoxia, as well as the molecular and physiological processes that occur in subjects exposed to HBOT. We discuss the efficacy of HBOT in treating neurological conditions and neurodevelopmental disorders in both humans and animal models. We summarize by discussing the challenges in this field, and explore future directions that will allow the scientific community to better understand the molecular aspects and applications of HBOT for a wide variety of neurological conditions.

miR-183-5p alleviates early injury after intracerebral hemorrhage by inhibiting heme oxygenase-1 expression

Differences in microRNA (miRNA) expression after intracerebral hemorrhage (ICH) have been reported in human and animal models, and miRNAs are being investigated as a new treatment for inflammation and oxidative stress after ICH. In this study, we found that microRNA-183-5p expression was decreased in the mouse brain after ICH. To investigate the effect of miRNA-183-5p on injury and repair of brain tissue after ICH, saline, miRNA-183-5p agomir, or miRNA-183-5p antagomir were injected into the lateral ventricles of 8-week-old mice with collagenase-induced ICH. Three days after ICH, mice treated with exogenous miRNA-183-5p showed less brain edema, neurobehavioral defects, inflammation, oxidative stress, and ferrous deposition than control mice. In addition, by alternately treating mice with a heme oxygenase-1 (HO-1) inducer, a HO-1 inhibitor, a nuclear factor erythroid 2-related factor (Nrf2) activator, and Nrf2 knockout, we demonstrated an indirect, HO-1-dependent regulatory relationship between miRNA-183-5p and Nrf2. Our results indicate that miRNA-183-5p and HO-1 are promising therapeutic targets for controlling inflammation and oxidative damage after hemorrhagic stroke.

The Hyperoxic-Hypoxic Paradox

Effective metabolism is highly dependent on a narrow therapeutic range of oxygen. Accordingly, low levels of oxygen, or hypoxia, are one of the most powerful inducers of gene expression, metabolic changes, and regenerative processes, including angiogenesis and stimulation of stem cell proliferation, migration, and differentiation. The sensing of decreased oxygen levels (hypoxia) or increased oxygen levels (hyperoxia), occurs through specialized chemoreceptor cells and metabolic changes at the cellular level, which regulate the response. Interestingly, fluctuations in the free oxygen concentration rather than the absolute level of oxygen can be interpreted at the cellular level as a lack of oxygen. Thus, repeated intermittent hyperoxia can induce many of the mediators and cellular mechanisms that are usually induced during hypoxia. This is called the hyperoxic-hypoxic paradox (HHP). This article reviews oxygen physiology, the main cellular processes triggered by hypoxia, and the cascade of events triggered by the HHP.

The Hyperoxic-Hypoxic Paradox

Effective metabolism is highly dependent on a narrow therapeutic range of oxygen. Accordingly, low levels of oxygen, or hypoxia, are one of the most powerful inducers of gene expression, metabolic changes, and regenerative processes, including angiogenesis and stimulation of stem cell proliferation, migration, and differentiation. The sensing of decreased oxygen levels (hypoxia) or increased oxygen levels (hyperoxia), occurs through specialized chemoreceptor cells and metabolic changes at the cellular level, which regulate the response. Interestingly, fluctuations in the free oxygen concentration rather than the absolute level of oxygen can be interpreted at the cellular level as a lack of oxygen. Thus, repeated intermittent hyperoxia can induce many of the mediators and cellular mechanisms that are usually induced during hypoxia. This is called the hyperoxic-hypoxic paradox (HHP). This article reviews oxygen physiology, the main cellular processes triggered by hypoxia, and the cascade of events triggered by the HHP.

miR‑187‑3p inhibitor attenuates cerebral ischemia/reperfusion injury by regulating Seipin‑mediated autophagic flux

MicroRNAs (miRNAs/miRs) have been reported to affect ischemia/reperfusion (I/R)-induced cerebral damage. miRNAs cause post-transcriptional gene silencing by binding to the protein-coding sequence (CDS) of mRNAs. Seipin has a potential role in regulating autophagic flux. The present study investigated the involvement of miR-187-3p in Seipin expression, autophagic flux and apoptosis in vitro, as well as the underlying mechanism, using PC12 cells exposed to oxygen-glucose deprivation/reoxygenation (OGD/R), which mimicked the process of I/R. In comparison with control PC12 cells, OGD/R caused an increase in the level of miR-187-3p and a decrease in Seipin protein levels without changes in the level of Seipin mRNA. Using bioinformatics analysis, it was identified that miR-187-3p could bind to the CDS of Seipin. miR-187-3p inhibitor attenuated the reduction in Seipin protein expression in OGD/R-treated PC12 cells. Following OGD/R, autophagic flux was reduced and apoptosis was enhanced, which were attenuated by inhibition of miR-187-3p. Compared with OGD/R-treated PC12 cells, Seipin knockdown further impaired autophagic flux and promoted neuronal apoptosis, which were insensitive to inhibition of miR-187-3p. Furthermore, treatment with miR-187-3p inhibitor could decrease the infarction volume in a rat model of middle cerebral artery occlusion/reperfusion. The present findings indicated that miR-187-3p inhibitor attenuated ischemia-induced cerebral damage by rescuing Seipin expression to improve autophagic flux.

Hydrogen inhibits microglial activation and regulates microglial phenotype in a mouse middle cerebral artery occlusion model

Microglia participate in bi-directional control of brain repair after stroke. Previous studies have demonstrated that hydrogen protects brain after ischemia/reperfusion (I/R) by inhibiting inflammation, but the specific mechanism of anti-inflammatory effect of hydrogen is poorly understood. The goal of our study is to investigate whether inhalation of high concentration hydrogen (HCH) is able to attenuate I/R-induced microglia activation. Eighty C57B/L male mice were divided into four groups: sham, I/R, I/R + HCH and I/R + N₂/O₂ groups. Assessment of animals happened in “blind” matter. I/R was induced by occlusion of middle cerebral artery for one hour). After one hour, filament was withdrawn, which induced reperfusion. Hydrogen treated I/R animals inhaled mix of 66.7% H₂ balanced with O₂ for 90 minutes, starting immediately after initiation of reperfusion. Control animals (N₂/O₂) inhaled mix in which hydrogen was replaced with N₂ for the same time (90 minutes). The brain injury, such as brain infarction and development of brain edema, as well as neurobehavioral deficits were determined 23 hours after reperfusion. Effect of HCH on microglia activation in the ischemic penumbra was investigated by immunostaining also 23 hours after reperfusion. mRNA expression of inflammation related genes was detected by PCR. Our results showed that HCH attenuated brain injury and consequently reduced neurological dysfunction after I/R. Furthermore, we demonstrated that HCH directed microglia polarization towards anti-inflammatory M2 polarization. This study indicates hydrogen may exert neuroprotective effects by inhibiting the microglial activation and regulating microglial polarization. This study was conducted in agreement with the Animal Care and Use Committee (IACUC) and Institutional Animal Care guidelines regulation (Shanghai Jiao Tong University, China (approval No. A2015-011) in November 2015.

miR-18b attenuates cerebral ischemia/reperfusion injury through regulation of ANXA3 and PI3K/Akt signaling pathway

Recent, research has displayed that the disorders of miR-18b are related to ischemic stroke. Here, we aimed to investigate the underlying neuroprotective mechanism of miR-18b in cerebral ischemia/reperfusion (I/R) injury. Oxygen-glucose deprivation/reperfusion (OGDR) model in vitro and middle cerebral artery occlusion (MCAO) model in vivo were established to simulate cerebral I/R injury. RT-PCR, western blotting, CCK-8, TUNEL, and TTC staining assays were applied in this study to explore the effect of miR-18b on cerebral I/R injury. Results displayed that miR-18b expression was reduced after cerebral I/R injury. Besides, miR-18b showed neuroprotective effects on cerebral I/R injury both in vitro and in vivo, These neuroprotective effects included promoting cell viability, decreasing cell apoptosis, reducing the production of inflammatory cytokines in SH-SY 5Y cells after OGDR and depressing MCAO-induced infarct size, neurological deficits and apoptotic cells in mice. Moreover, miR-18b negatively regulated ANXA3 expression, and its neuroprotection on cerebral I/R injury was overturned by ANXA3. Additionally, increasing miR-18b or decreasing ANXA3 promoted the activation of the PI3K/Akt signaling pathway in SH-SY 5Y cells after cerebral I/R injury. In conclusion, these data indicate that miR-18b protects against cerebral I/R injury by inhibiting ANXA3 and activating PI3K/Akt pathway, which provides a promising therapeutic target for ischemic stroke therapy.

Activation of TGR5 protects blood brain barrier via the BRCA1/Sirt1 pathway after middle cerebral artery occlusion in rats

BACKGROUND

The disruption of the blood-brain barrier (BBB) plays a critical event in the pathogenesis of ischemia stroke. TGR5 is recognized as a potential target for the treatment for neurologic disorders.

METHODS

This study investigated the roles of TGR5 activation in attenuating BBB damage and underlying mechanisms after middle cerebral artery occlusion (MCAO). Sprague-Dawley rats were subjected to model of MCAO and TGR5 agonist, INT777, was administered intranasally. Small interfering RNA (siRNA) for TGR5 and BRCA1 were administered through intracerebroventricular injection 48 h before MCAO. Infarct volumes, brain water content, BBB permeability, neurological scores, Western blot, immunofluorescence staining and co- immunoprecipitation were evaluated.

RESULTS

Endogenous TGR5 and BRCA1 were upregulated in the injured hemisphere after MCAO and TGR5 expressed in endothelial cells. Treatment with INT777 alleviated brain water content and BBB permeability, reduced infarction volume and improved neurological scores at 24 h and 72 h after ischemia. INT777 administration increased BRCA1 and Sirt1 expression, as well as upregulated expressions of tight junction proteins. Ischemic damage induced interaction of TGR5 with BRCA1. TGR5 siRNA and BRCA1 siRNA significantly inhibited expressions of BRCA1 and Sirt1, aggravated BBB permeability and exacerbated stroke outcomes after MCAO. The protective effects of INT777 at 24 h after MCAO were also abolished by TGR5 siRNA or BRCA1 siRNA.

CONCLUSIONS

Our findings demonstrate that activating TGR5 could reduce BBB breakdown and improve neurological functions through BRCA1/Sirt1 signaling pathway after MCAO. TGR5 may serve as a potential new candidate to relieve brain injury after MCAO.

Ginsenoside-Rb1 for Ischemic Stroke: A Systematic Review and Meta-analysis of Preclinical Evidence and Possible Mechanisms

Background

Ischemic stroke is the most common type of stroke, while pharmacological therapy options are limited. Ginsenosides are the major bioactive compounds in Ginseng and have been found to have various pharmacological effects in the nervous system. In the present study, we sought to evaluate the effects of Ginsenoside-Rb1 (G-Rb1), an important ingredient of ginsenosides, and the probable neuroprotective mechanisms in experimental ischemic strokes.

Methods

Studies of G-Rb1 on ischemic stroke animal models were identified from 7 databases. No clinical trials were included in the analysis. The primary outcome measures were neurological function scores, infarct volume, evans blue content and/or brain water content (BWC). The second outcome measures were the possible neuroprotective mechanisms. All the data were analyzed by Rev Man 5.3.

Result

Pooled preclinical data showed that compared with the controls, G-Rb1 could improve neurological function (Zea Longa (n = 367, P < 0.01); mNSS (n = 70, P < 0.01); Water maze test (n = 48, P < 0.01); Bederson (n = 16, P < 0.01)), infarct area (TTC (n = 211, P < 0.01); HE (n = 26, P < 0.01)), as well as blood-brain barrier function (BWC (n = 64, P < 0.01); Evans blue content (n=26, P < 0.05)). It also can increase BDNF (n = 26, P < 0.01), Gap-43 (n = 16, P < 0.01), SOD (n = 30, P < 0.01), GSH (n = 16, P < 0.01), Nissl-positive cells (n = 12, P < 0.01), Nestin-positive cells (n = 10, P < 0.05), and reduce Caspase-3 (n = 36, P < 0.01), IL-1 (n = 32, P < 0.01), TNF-α (n = 72, P < 0.01), MDA (n = 18, P < 0.01), NO (n = 44, P < 0.01), NOX (n = 32, P < 0.05), ROS (n = 6, P < 0.05), NF-κB (P < 0.05) and TUNEL-positive cells (n = 52, P < 0.01).

Conclusion

Available findings demonstrated the preclinical evidence that G-Rb1 has a potential neuroprotective effect, largely through attenuating brain water content, promoting the bioactivities of neurogenesis, anti-apoptosis, anti-oxidative, anti-inflammatory, energy supplement and cerebral circulation.