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Abstract Background Reactive oxygen species (ROS) often promote acute brain injury after stroke, but their roles in the recovery phase have not been well studied. We tested the hypothesis that ROS activity mediated by NADPH oxidase 2 (NOX2) contributes to acute brain injury but promotes functional recovery during the delayed phase, which is linked with neuroinflammation, autophagy, angiogenesis, and the PI3K/Akt signaling pathway. Methods We used the NOX2 inhibitor apocynin to study the role of NOX2 in brain injury and functional recovery in a middle cerebral artery occlusion (MCAO) stroke mouse model. Infarct size, neurological deficits and behavior were evaluated on days 3, 7, 10 and 14 after reperfusion. In addition, dynamic NOX2-induced ROS levels were measured by dihydroethidium (DHE) staining. Autophagy, inflammasomes, and angiogenesis were measured by immunofluorescence staining and western blotting. RNA sequencing was performed, and bioinformatics technology was used to analyze differentially expressed genes (DEGs), as well as the enrichment of biological functions and signaling pathways in ischemia penumbra at 7 days after reperfusion. Then, Akt pathway-related proteins were further evaluated by western blotting. Results Our results showed that apocynin injection attenuated infarct size and mortality 3 days after stroke but promoted mortality and blocked functional recovery from 5 to 14 days after stroke. DHE staining showed that ROS levels were increased at 3 days after reperfusion and then gradually declined in WT mice, and these levels were significantly reduced by the NOX2 inhibitor apocynin. RNA-Seq analysis indicated that apocynin activated the immune response under hypoxic conditions. The immunofluorescence and western blot results demonstrated that apocynin inhibited the NLRP3 inflammasome and promoted angiogenesis at 3 days but promoted the NLRP3 inflammasome and inhibited angiogenesis at 7 and 14 days after stroke, which was mediated by regulating autophagy activation. Furthermore, RNA-Seq and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that apocynin injection resulted in PI3K–Akt signaling pathway enrichment after 7 days of MCAO. We then used an animal model to show that apocynin decreased the protein levels of phosphorylated PI3K and Akt and NF-κB p65, confirming that the PI3K–Akt–NF-κB pathway is involved in apocynin-mediated activation of inflammation and inhibition of angiogenesis. Conclusions NOX2-induced ROS production is a double-edged sword that exacerbates brain injury in the acute phase but promotes functional recovery. This effect appears to be achieved by inhibiting NLRP3 inflammasome activation and promoting angiogenesis via autophagy activation.

Aim: This study aimed to explore the mechanisms of transient receptor potential (TRP) channels on the immune microenvironment and develop a TRP‐related signature for predicting prognosis, immunotherapy response, and drug sensitivity in gliomas. Methods: Based on the unsupervised clustering algorithm, we identified novel TRP channel clusters and investigated their biological function, immune microenvironment, and genomic heterogeneity. In vitro and in vivo experiments revealed the association between TRPV2 and macrophages. Subsequently, based on 96 machine learning algorithms and six independent glioma cohorts, we constructed a machine learning‐based TRP channel signature (MLTS). The performance of the MLTS in predicting prognosis, immunotherapy response, and drug sensitivity was evaluated. Results: Patients with high expression levels of TRP channel genes had worse prognoses, higher tumor mutation burden, and more activated immunosuppressive microenvironment. Meanwhile, TRPV2 was identified as the most essential regulator in TRP channels. TRPV2 activation could promote macrophages migration toward malignant cells and alleviate glioma prognosis. Furthermore, MLTS could work independently of common clinical features and present stable and superior prediction performance. Conclusion: This study investigated the comprehensive effect of TRP channel genes in gliomas and provided a promising tool for designing effective, precise treatment strategies. [ABSTRACT FROM AUTHOR]

BackgroundCardiac arrest/cardiopulmonary resuscitation (CA/CPR) represents one of the devastating medical emergencies and is associated with high mortality and neuro-disability. Post-cardiac arrest syndrome (PCAS) is mechanistically ascribed to acute systemic ischemia/reperfusion(I/R) injury. The lncRNA/microRNA/mRNA networks have been found to play crucial roles in the pathogenesis of the hypoxia-responsive diseases. Nonetheless, the precise molecular mechanisms by which lncRNA/miRNA/mRNA axes are involved in the astrocyte–microglia crosstalk in CA/CPR have not been fully elucidated.MethodsWe collected and purified the exosomes from the blood of CA/CPR patients and supernatant of OGD/R-stimulated astrocytes. On the basis of microarray analysis, bioinformatic study, and luciferase activity determination, we speculated that lncRNA GAS5/miR-137 is implicated in the astrocyte–microglia crosstalk under the insult of systemic I/R injury. The regulation of lncRNA GAS5/miR-137 on INPP4B was examined by cellular transfection in OGD/R cell culture and by lateral ventricle injection with miR-137 agomir in CA/CPR mice model. Flow cytometry and immunofluorescence staining were performed to detect the microglial apoptosis, M1/M2 phenotype transformation, and neuroinflammation. Neurological scoring and behavior tests were conducted in CA/CPR group, with miR-137 agomir lateral-ventricle infusion and in their controls.ResultsIn all the micRNAs, miR-137 was among the top 10 micRNAs that experienced greatest changes, in both the blood of CA/CPR patients and supernatant of OGD/R-stimulated astrocytes. Bioinformatic analysis revealed that miR-137 was sponged by lncRNA GAS5, targeting INPP4B, and the result was confirmed by Luciferase activity assay. qRT-PCR and Western blotting showed that lncRNA GAS5 and INPP4B were over-expressed whereas miR-137 was downregulated in the blood of CA/CPR patients, OGD/R-stimulated astrocytes, and brain tissue of CA/CPR mice. Silencing lncRNA GAS5 suppressed INPP4B expression, but over-expression of miR-137 negatively modulated its expression. Western blotting exhibited that PI3K and Akt phosphorylation was increased when lncRNA GAS5 was silenced or miR-137 was over-expressed. However, PI3K and Akt phosphorylation was notably suppressed in the absence of miR-137, almost reversing their phosphorylation in the silencing lncRNA GAS5 group. Then we found that GAS5 siRNA or miR-137 mimic significantly increased cell viability and alleviated apoptosis after OGD/R injury. Furthermore, over-expression of miR-137 attenuated microglial apoptosis and neuroinflammation in CA/CPR mice model, exhibiting significantly better behavioral tests after CA/CPR.ConclusionLncRNA GAS5/miR-137 may be involved in the astrocyte–microglia communication that inhibits PI3K/Akt signaling activation via regulation of INPP4B during CA/CPR.

Aims: Mitochondria‐associated endoplasmic reticulum membranes (MAMs) serve as a crucial bridge connecting the endoplasmic reticulum (ER) and mitochondria within cells. Vesicle‐associated membrane protein‐associated protein B (VAPB) and protein tyrosine phosphatase interacting protein 51 (PTPIP51) are responsible for the formation and stability of MAMs, which have been implicated in the pathogenesis of various diseases. However, the role of MAMs in ischemic stroke (IS) remains unclear. We aimed to investigate the role of MAMs tethering protein VAPB‐PTPIP51 in experimental cerebral ischemia. Methods: We simulated cerebral ischemia–reperfusion injury (CIRI) by using a mouse middle cerebral artery occlusion (MCAO) model. Results: We observed a decrease in VAPB‐PTPIP51 expression in the brain tissue. Our findings suggested compromised MAMs after MCAO, as a decreased mitochondria–ER contact (MERC) coverage and an increased distance were observed through the transmission electron microscope (TEM). Upon VAPB or PTPIP51 knockdown, the damage to MAMs was exacerbated, accompanied by excessive autophagy activation and increased reactive oxygen species (ROS) production, resulting in an enlarged infarct area and exacerbated neurological deficits. Notably, we observed that this damage was concomitant with the inhibition of the PI3K/AKT/mTOR pathway and was successfully mitigated by the treatment with the PI3K activator. Conclusions: Our findings suggest that the downregulation of VAPB‐PTPIP51 expression after IS mediates structural damage to MAMs. This may exacerbate CIRI by inhibiting the PI3K pathway and activating autophagy, thus providing new therapeutic targets for IS. [ABSTRACT FROM AUTHOR]

Aims: The crosstalk between ferroptosis and neuroinflammation considerably impacts the pathogenesis of cerebral ischemia–reperfusion injury (CIRI). Neutral polysaccharide from Gastrodia elata (NPGE) has shown significant effects against oxidative stress and inflammation. This study investigated the potential effects of NPGE on CIRI neuropathology. Methods: The effects of NPGE were studied in a mouse model of ischemic stroke (IS) and in oxygen–glucose deprivation/reperfusion (OGD/R)‐induced HT22 cells. Results: NPGE treatment decreased neurological deficits, reduced infarct volume, and alleviated cerebral edema in IS mice, and promoted the survival of OGD/R‐induced HT22 cells. Mechanistically, NPGE treatment alleviated neuronal ferroptosis by upregulating GPX4 levels, lowering reactive oxygen species (ROS), malondialdehyde (MDA), and Fe2+ excessive hoarding, and meliorating GSH levels and SOD activity. Additionally, it inhibited neuroinflammation by down‐regulating the level of IL‐1β, IL‐6, TNF‐α, NLRP3, and HMGB1. Meanwhile, NPGE treatment alleviated ferroptosis and inflammation in erastin‐stimulated HT22 cells. Furthermore, NPGE up‐regulated the expression of NRF2 and HO‐1 and promoted the translocation of NRF2 into the nucleus. Using the NRF2 inhibitor brusatol, we verified that NRF2/HO‐1 signaling mediated the anti‐ferroptotic and anti‐inflammatory properties of NPGE. Conclusion: Collectively, our results demonstrate the protective effects of NPGE and highlight its therapeutic potential as a drug component for CIRI treatment. [ABSTRACT FROM AUTHOR]

Aims: Cell death, except for cuproptosis, in gliomas has been extensively studied, providing novel targets for immunotherapy by reshaping the tumor immune microenvironment through multiple mechanisms. This study aimed to explore the effect of cuproptosis on the immune microenvironment and its predictive power in prognosis and immunotherapy response. Methods: Eight glioma cohorts were included in this study. We employed the unsupervised clustering algorithm to identify novel cuproptosis clusters and described their immune microenvironmental characteristics, mutation landscape, and altered signaling pathways. We verified the correlation among FDX1, SLC31A1, and macrophage infiltration in 56 glioma tissues. Next, based on multicenter cohorts and 10 machine learning algorithms, we constructed an artificial intelligence–driven cuproptosis‐related signature named CuproScore. Results: Our findings suggested that glioma patients with high levels of cuproptosis had a worse prognosis owing to immunosuppression caused by unique immune escape mechanisms. Meanwhile, we experimentally validated the positive association between cuproptosis and macrophages and its tumor‐promoting mechanism in vitro. Furthermore, our CuproScore exhibited powerful and robust prognostic predictive ability. It was also capable of predicting response to immunotherapy and chemotherapy drug sensitivity. Conclusions: Cuproptosis facilitates immune activation but promotes immune escape. The CuproScore could predict prognosis and immunotherapy response in gliomas. [ABSTRACT FROM AUTHOR]