Apoptosis In Cortical Neurons Research Articles

Embryonic exposure to 6:2 fluorotelomer alcohol mediates autism spectrum disorder-like behavior by dysfunctional microbe-gut-brain axis in mice

6:2 fluorotelomer alcohol (6:2 FTOH) is considered an emerging contaminant as a substitute for perfluoroalkyl and polyfluoroalkyl substances. Autism spectrum disorder (ASD) is a highly heterogeneous childhood neurodevelopmental disorder, the prevalence of which has been significantly increasing globally, possibly due to rising exposure to environmental pollutants. Additionally, the microbe-gut-brain axis plays a crucial role in the development of ASD. The purpose of study was to investigate the impact of embryonic 6:2 FTOH exposure on neurological development in mice and explore the potential involvement of the microbe-gut-brain. Pregnant mice were orally administered 6:2 FTOH from gestation day 8.5 until delivery, and follow-up testing was performed on day 22 post-delivery. The findings revealed that embryonic exposure to 6:2 FTOH led to ASD-like symptoms, cortical neuron apoptosis, glial cell activation, and abnormal synapse formation in mice. Furthermore, impairment of colonic barrier function, inflammatory response, and dysbiosis in gut microbiota were observed. Interestingly, supplementation with Lactobacillus rhamnosus GG during embryonic development mitigated these adverse outcomes. This study enhances our understanding of how environmental pollutants can impact neurological development in children and provides valuable insights for clinical prevention, diagnosis, and treatment strategies for non-genetic ASD.

Protein Kinase C-Delta Mediates Cell Cycle Reentry and Apoptosis Induced by Amyloid-Beta Peptide in Post-Mitotic Cortical Neurons.

Amyloid-beta peptide (Aβ) is a neurotoxic constituent of senile plaques in the brains of Alzheimer's disease (AD) patients. The detailed mechanisms by which protein kinase C-delta (PKCδ) contributes to Aβ toxicity is not yet entirely understood. Using fully differentiated primary rat cortical neurons, we found that inhibition of Aβ25-35-induced PKCδ increased cell viability with restoration of neuronal morphology. Using cyclin D1, proliferating cell nuclear antigen (PCNA), and histone H3 phosphorylated at Ser-10 (p-Histone H3) as the respective markers for the G1-, S-, and G2/M-phases, PKCδ inhibition mitigated cell cycle reentry (CCR) and subsequent caspase-3 cleavage induced by both Aβ25-35 and Aβ1-42 in the post-mitotic cortical neurons. Upstream of PKCδ, signal transducers and activators of transcription (STAT)-3 mediated PKCδ induction, CCR, and caspase-3 cleavage upon Aβ exposure. Downstream of PKCδ, aberrant neuronal CCR was triggered by overactivating cyclin-dependent kinase-5 (CDK5) via calpain2-dependent p35 cleavage into p25. Finally, PKCδ and CDK5 also contributed to Aβ25-35 induction of p53-upregulated modulator of apoptosis (PUMA) in cortical neurons. Together, we demonstrated that, in the post-mitotic neurons exposed to Aβs, STAT3-dependent PKCδ expression triggers calpain2-mediated p35 cleavage into p25 to overactivate CDK5, thus leading to aberrant CCR, PUMA induction, caspase-3 cleavage, and ultimately apoptosis.

Genipin 1-O-β-D-gentiobioside ameliorates CUMS-induced prefrontal cortex neuron neuronal apoptosis by modulating HIPK2 SUMOylation

BackgroundDepression is a common mental illness with more than 280 million sufferers worldwide. Inflammation, particularly the c-Jun amino-terminal kinase (JNK) pathway, contributes to depression development and neuronal apoptosis. Gardenia is a herb with therapeutic effects on depression that has been shown to inhibit neuronal apoptosis. However, one of the components in gardenia, Genipin 1-O-β-D-gentiobioside(GG), has been less studied for its mechanism on depression. Thus, in the current study, we investigate how Genipin 1-O-β-D-gentiobioside improves depression and elucidate its possible mechanism of action. MethodsIn this investigation, we utilize a chronic unpredictable mild stress (CUMS) mouse model and corticosterone-induced primary cortical neurons to examine the role of GG in ameliorating depressive symptoms and neuronal apoptosis. TUNEL staining and flow cytometry assessed the effects of GG on neuronal apoptosis. Western Blot analyses and immunofluorescence assays apoptosis-related proteins in the prefrontal cortex and primary neurons. The site of action of GG in regulating homeodomain interacting protein kinase 2 (HIPK2) SUMOylation was further explored in primary neurons. We constructed siRNA-SUMO1 vectors to transfect primary neuronal cells with intracellular SUMO1 knockdown. Proximity ligation assay (PLA) experiments were performed on primary neurons according to the instructions of the assay kit to observe the physical relationship between HIPK2 and SUMO1. We predicted the HIPK2 SUMOylation modification site by an online database and constructed vectors to target and site-directed mutagenesis, then to transfected primary neuronal cells. ResultsThe results showed that GG effectively alleviated depressive-like behaviours, down-regulated apoptosis-related proteins (p-JNK, Bax, Cleaved-Caspase-3), and inhibited neuronal apoptosis in CUMS-induced depressed mice and corticosterone-induced primary cortical neurons. We reveal a complex mechanism underlying the link between GG, SUMOylation of HIPK2, and complex pathways of neuronal apoptosis regulation. K326 and K1189 are the key SUMOylation sites regulated by GG in intricate interactions of apoptosis-related proteins. ConclusionOur study demonstrated that GG exerts antidepressant-like actions through neuroprotective effects by inhibiting the apoptosis of prefrontal cortex neurons, revealing the mechanism of GG inhibition of JNK phosphorylation by enhancing HIPK2 SUMOylation.

3'-Daidzein Sulfonate Sodium Protects against Glutamate-induced Neuronal Injuries by Regulating NMDA Receptors.

It was previously found that 3'-Daidzein Sulfonate Sodium (DSS) exhibits protective effects on cerebral ischemia/reperfusion injury (CI/RI). This study aimed to explore the underlying molecular mechanisms involved in the neuroprotective effects of DSS against ischemic stroke. In this study, rats with transient middle cerebral artery occlusion (tMCAO) were used as an in vivo model, whereas PC12 cells treated with glutamate alone and rat primary cortical neurons treated with the combination of glutamate and glycine were used as in vitro models. Cell viability and lactate dehydrogenase (LDH) release were used to evaluate cell injury. Cell apoptosis was determined by flow cytometry. Quantitative polymerase chain reaction (qPCR), Western blotting, and immunofluorescent staining methods were used to determine the mRNA expressions and protein levels and location. It was found that DSS significantly suppressed the impaired viability of PC12 cells induced by glutamate. DSS also increased cell viability while reducing the LDH release and apoptosis in primary cortical neurons injured by glutamate and glycine. In addition, DSS decreased GluN2B subunit expression while enhancing the expressions of GluN2A subunit and PSD95 in tMCAO rats' brains. This study demonstrated that DSS protects against excitotoxic damage in neurons induced by CI/RI through regulating the expression of NMDA receptors and PSD95. Our findings provide experimental evidence for the potential clinical administration of DSS in ischemic stroke.

Electroacupuncture regulates histone acetylation of Bcl-2 and Caspase-3 genes to improve ischemic stroke injury

BackgroundImbalances between Bcl-2 and caspase-3 are significant evidence of apoptosis, which is considered an influential factor in rapidly occurring neuronal cell death and the decline of neurological function after stroke. Studies have shown that acupuncture can reduce poststroke brain cell damage via either an increase in Bcl-2 or a reduction in caspase-3 exposure. The current study aimed to investigate whether acupuncture could modulate Bcl-2 and caspase-3 expression through histone acetylation modifications, which could potentially serve as a neuroprotective mechanism. MethodsThis study used TTC staining, Nissl staining, Clark neurological system score, and Evans Blue (EB) extravasation to evaluate neurological damage following stroke. The expression of Bcl-2/caspase-3 mRNA was detected by real-time fluorescence quantification of PCR (real-time PCR), whereas the protein expression levels of Bcl-2, Bax, caspase-3, and cleaved caspase-3 were assessed using western blotting. TUNEL staining of the ischemic cortical neurons determined apoptosis in the ischemic cortex. Histone acetyltransferase (HAT) and histone deacetylase (HDAC) activities, along with the protein performance of AceH3, H3K9ace, and H3K27ace, were detected to evaluate the degree of histone acetylation. The acetylation enrichment levels of H3K9 and K3K27 in the Bcl-2/caspase-3 gene were assessed using Chromatin Immunoprecipitation (ChIP) assay. ResultsOur data demonstrated that electroacupuncture (EA) exerts a significant neuroprotective effect in middle cerebral artery occlusion (MCAO) rats, as evidenced by a reduction in infarct volume, neuronal damage, Blood-Brain Barrier (BBB) disruption, and decreased apoptosis of ischemic cortical neurons. EA treatment can promote the mRNA and protein expression of the Bcl-2 gene in the ischemic brain while reducing the mRNA and protein expression levels of caspase-3 and effectively decreasing the protein expression levels of Bax and cleaved caspase-3. More importantly, EA treatment enhanced the level of histone acetylation, including Ace-H3, H3K9ace, and H3K27ace, significantly enhanced the occupancy of H3K9ace/H3K27ace at the Bcl-2 promoter, and reduced the enrichment of H3K9ace and H3K27ace at the caspase-3 promoter. However, the Histone Acetyltransferase inhibitor (HATi) treatment reversed these effects. ConclusionsOur data demonstrated that EA mediated the expression levels of Bcl-2 and caspase-3 in MCAO rats by regulating the occupancy of acetylated H3K9/H3K27 at the promoters of these two genes, thus exerting a cerebral protective effect in ischemic reperfusion (I/R) injury.

Effect of electroacupuncture on neuronal programmed necrosis by regulating RIP1/RIP3/MLKL pathway in rats with cerebral ischemia reperfusion injury.

To investigate the neuroprotective effect of electroacupuncture (EA) at "Quchi"(LI11) and "Zusanli"(ST36) in the rats with cerebral ischemia reperfusion injury and its influence on programmed necrosis of cerebral cortical neurons. Sixty male SD rats were randomly divided into sham-operation group, model group, EA group and inhibitor group, with 15 rats in each group. Left middle cerebral artery occlusion model was established using the modified thread embolism method. In the sham-operation group, the carotid artery was exposed and dissociated in each rat. EA was applied to "Quchi"(LI11) and "Zusanli"(ST36) on the right side for 30 min each time, once daily for 7 days in the rats of the EA group. The rats in the inhibitor group were intraperitoneally injected with norstatin-1 (0.6 mg/kg) for consecutive 7 days. The neurological deficit score of rats in each group was observed. HE staining was adopted to detect the degree of pathological damage of the cerebral cortex in the infarction area. Using TUNEL staining, the apoptosis of cortical neurons in the infarction area was determined；the contents of tumor necrosis factor α (TNF-α), interleukin (IL)-1β and IL-6 were detected by ELISA；the mRNA and protein expression of the receptor interacting protein-1 (RIP1), the receptor interacting protein-3 (RIP3) and the substrate mixed lineage kinase like protein (MLKL) were detected by fluorescence quantitative PCR and Western blot, respectively. In comparison with the sham-operation group, the neurological deficit score in the model group was higher(P<0.01)；HE staining showed that there was the pathological damage in the infarction area；the neuron apoptosis rate, the contents of TNF-α, IL-1β and IL-6, and the mRNA and protein expressions of RIP1, RIP3 and MLKL increased(P<0.01) in the model group. In the EA group, the neurological deficit score was reduced(P<0.01)；HE staining showed that the pathological damage was ameliorated in the infarction area；the neuron apoptosis rate, the contents of TNF-α, IL-1β and IL-6, and the mRNA and protein expressions of RIP1, RIP3, MLKL decreased(P<0.05, P<0.01) when compared with those in the model group. EA can attenuate cerebral ischemia reperfusion injury and display its neuroprotective effect probably through inhibiting programmed necrosis of cerebral cortical neurons in the rats.

Differential regulations of neural activity and survival in primary cortical neurons by PFOA or PFHpA

Perfluorinated compounds (PFCs), organofluoride compounds comprising carbon–fluorine and carbon–carbon bonds, are used as water and oil repellents in textiles and pharmaceutical tablets; however, they are associated with potential neurotoxic effects. Moreover, the impact of PFCs on neuronal survival, activity, and regulation within the brain remains unclear. Additionally, the mechanisms through which PFCs induce neuronal toxicity are not well-understood because of the paucity of data. This study elucidates that perfluorooctanoic acid (PFOA) and perfluoroheptanoic acid (PFHpA) exert differential effects on the survival and activity of primary cortical neurons. Although PFOA triggers apoptosis in cortical neurons, PFHpA does not exhibit this effect. Instead, PFHpA modifies dendritic spine morphogenesis and synapse formation in primary cortical neuronal cultures, additionally enhancing neural activity and synaptic transmission. This research uncovers a novel mechanism through which PFCs (PFHpA and PFOA) cause distinct alterations in dendritic spine morphogenesis and synaptic activity, shedding light on the molecular basis for the atypical behaviors noted following PFC exposure. Understanding the distinct effects of PFHpA and PFOA could guide regulatory policies on PFC usage and inform clinical approaches to mitigate their neurotoxic effects, especially in vulnerable population.

The action mechanism by which C1q/tumor necrosis factor-related protein-6 alleviates cerebral ischemia/reperfusion injury in diabetic mice.

JOURNAL/nrgr/04.03/01300535-202409000-00034/figure1/v/2024-01-16T170235Z/r/image-tiff Studies have shown that C1q/tumor necrosis factor-related protein-6 (CTRP6) can alleviate renal ischemia/reperfusion injury in mice. However, its role in the brain remains poorly understood. To investigate the role of CTRP6 in cerebral ischemia/reperfusion injury associated with diabetes mellitus, a diabetes mellitus mouse model of cerebral ischemia/reperfusion injury was established by occlusion of the middle cerebral artery. To overexpress CTRP6 in the brain, an adeno-associated virus carrying CTRP6 was injected into the lateral ventricle. The result was that oxygen injury and inflammation in brain tissue were clearly attenuated, and the number of neurons was greatly reduced. In vitro experiments showed that CTRP6 knockout exacerbated oxidative damage, inflammatory reaction, and apoptosis in cerebral cortical neurons in high glucose hypoxia-simulated diabetic cerebral ischemia/reperfusion injury. CTRP6 overexpression enhanced the sirtuin-1 signaling pathway in diabetic brains after ischemia/reperfusion injury. To investigate the mechanism underlying these effects, we examined mice with depletion of brain tissue-specific sirtuin-1. CTRP6-like protection was achieved by activating the sirtuin-1 signaling pathway. Taken together, these results indicate that CTRP6 likely attenuates cerebral ischemia/reperfusion injury through activation of the sirtuin-1 signaling pathway.

Distinct manifestations and potential mechanisms of seizures due to cortical versus white matter injury in children

PurposeTo study seizure manifestations and outcomes in children with cortical versus white matter injury, differences potentially explaining variability of epilepsy in children with cerebral palsy. MethodsIn this population-based retrospective cohort study, MRIs of children with cerebral palsy due to ischemia or haemorrhage were classified according to presence or absence of cortical injury. MRI findings were then correlated with history of neonatal seizures, seizures during childhood, epilepsy syndromes, and seizure outcomes. ResultsOf 256 children studied, neonatal seizures occurred in 57 and seizures during childhood occurred in 93. Children with neonatal seizures were more likely to develop seizures during childhood, mostly those with cortical injury. Cortical injury was more strongly associated with (1) developing seizures during childhood, (2) more severe epilepsy syndromes (infantile spasms syndrome, focal epilepsy, Lennox-Gastaut syndrome), and (3) less likelihood of reaching > 2 years without seizures at last follow-up, compared to children without cortical injury. Children without cortical injury, mainly those with white matter injury, were less likely to develop neonatal seizures and seizures during childhood, and when they did, epilepsy syndromes were more commonly febrile seizures and self-limited focal epilepsies of childhood, with most achieving > 2 years without seizures at last follow-up. The presence of cortical injury also influenced seizure occurrence, severity, and outcome within the different predominant injury patterns of the MRI Classification System in cerebral palsy, most notably white matter injury. ConclusionsEpileptogenesis is understood with cortical injury but not well with white matter injury, the latter potentially related to altered postnatal white matter development or myelination leading to apoptosis, abnormal synaptogenesis or altered thalamic connectivity of cortical neurons. These findings, and the potential mechanisms discussed, likely explain the variability of epilepsy in children with cerebral palsy and epilepsy following early-life brain injury in general.

Protective mechanisms of tea polyphenols regulating the PI3K/Akt pathway on early brain injury after subarachnoid hemorrhage in rats.

In recent years, numerous studies have demonstrated that tea polyphenols (TPPs) can exert neuroprotective effects through the regulation of the PI3K/Akt pathway. The objective of this work was to verify whether TPPs could protect against early brain injury in rats after subarachnoid hemorrhage (SAH) by modulating the PI3K/Akt pathway. A total of 150 rats were randomly rolled into control (C), TPP, and SAH groups. The TPP and SAH groups underwent endovascular perforation to induce SAH, while C group received only endovascular needle puncture and saline injection. Brain water content, Evans Blue (EB) extravasation assay, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, Western blot, and RT-PCR analyses were performed. Relative to SAH group, TPP treatment considerably improved neurological function scores following SAH, reduced brain edema, cortical neuronal apoptosis, and blood-brain barrier damage. Levels of aquaporin-4 (AQP4) and apoptosis-related protein Bax were considerably lower in the TPP group than in SAH group. Conversely, levels of anti-apoptotic protein Bcl-2 and tight junction protein Zona occludens 1 (ZO-1) were considerably higher in the TPP group. Furthermore, TPP treatment was found to activate the PI3K/Akt signaling. TPPs can mitigate early brain injury caused by SAH in rats by reducing AQP4 levels, alleviating cortical damage, and attenuating neuronal apoptosis. These findings elucidate the protective mechanisms of TPPs against early brain injury following SAH through the regulation of the PI3K/Akt signaling.

Abstract 175: Adiponectin Alleviates Cortical Neuronal Apoptosis Following Cardiopulmonary Resuscitation by Attenuating MiR-31-5p Carried by Brain Microvascular Endothelial Cell-Derived Extracellular Vesicles

Background: Adiponectin (APN) is a cardiovascular-protective adipokine. Our previous research has shown that APN administration reduced cortical neuron apoptosis in mice after resuscitation. Brain microvascular endothelial cell-derived extracellular vesicles (BMEC-sEVs) have neuroprotective properties, and APN regulates BMEC-sEVs' function to alleviate neuronal apoptosis after resuscitation. However, the specific molecular mechanisms are unclear. MicroRNAs carried by sEVs play essential roles. Hypothesis: APN may alleviate cortical neuron apoptosis by regulating miRNAs carried by BMEC-sEVs. Aims: To investigate if APN attenuates cortical neuron apoptosis in mice after resuscitation by regulating BMEC-sEVs-miRNAs and to elucidate the underlying molecular mechanisms. Methods: BMEC-sEVs APN were extracted and identified. BMEC-sEVs were injected into the brain to establish a cardiopulmonary resuscitation mouse model, and cortical neuron apoptosis was assessed. Co-culture experiments were performed between BMEC-sEVs and primary cortical neurons, and apoptosis was evaluated after oxygen-glucose deprivation/reperfusion (OGD/R). Bioinformatics identified miRNAs with pro-apoptotic effects. APN-regulated specific BMEC-sEV miRNAs were screened. Overexpression and inhibition experiments confirmed the neuroprotective effects of the identified miRNA. Target genes were screened, and downstream signaling pathways were explored. Results: APN enhanced the protective effect of BMEC-sEVs against cortical neuron apoptosis. APN preconditioning reduced miR-155-5p and miR-31-5p levels in BMEC-sEVs APN . MiR-31-5p was highly expressed in primary BMECs and increased after OGD/R. Overexpression of miR-31-5p in cortical neurons aggravated neuronal apoptosis. Inhibition of miR-31-5p reduced apoptotic neurons in Adipoq -/- mice after ROSC. Map3k1 was the most affected target gene of miR-31-5p, and its regulatory role in cortical neuron apoptosis was confirmed. Conclusion: APN alleviates cortical neuron apoptosis after resuscitation by downregulating miR-31-5p expression in BMEC-sEVs; BMEC-sEVs APN alleviate cortical neuron apoptosis through the miR-31-5p/MAP3K1 signaling pathway.

Effect and molecular mechanism of Sulforaphane alleviates brain damage caused by acute carbon monoxide poisoning:Network pharmacology analysis, molecular docking, and experimental evidence.

Sulforaphane (SFN) has attracted much attention due to its ability on antioxidant, anti-inflammatory, and anti-apoptotic properties, while its functional targets and underlying mechanism of action on brain injury caused by acute carbon monoxide poisoning (ACOP) have not been fully elucidated. Herein, we used a systematic network pharmacology approach to explore the mechanism of SFN in the treatment of brain damage after ACOP. In this study, the results of network pharmacology demonstrated that there were a total of 81 effective target genes of SFN and 36 drug-disease targets, which were strongly in connection with autophagy-animal signaling pathway, drug metabolism, and transcription disorders in cancer. Upon the further biological function and KEGG signaling pathway enrichment analysis, a large number of them were involved in neuronal death, reactive oxygen metabolic processes and immune functions. Moreover, based on the results of bioinformatics prediction associated with multiple potential targets and pathways, the AMP-activated protein kinase (AMPK) signaling pathway was selected to elucidate the molecular mechanism of SFN in the treatment of brain injury caused by ACOP. The following molecular docking analysis also confirmed that SFN can bind to AMPKα well through chemical bonds. In addition, an animal model of ACOP was established by exposure to carbon monoxide in a hyperbaric oxygen chamber to verify the predicted results of network pharmacology. We found that the mitochondrial ultrastructure of neurons in rats with ACOP was seriously damaged, and apoptotic cells increased significantly. The histopathological changes were obviously alleviated, apoptosis of cortical neurons was inhibited, and the number of Nissl bodies was increased in the SFN group as compared with the ACOP group (p < .05). Besides, the administration of SFN could increase the expressions of phosphorylated P-AMPK and MFN2 proteins and decrease the levels of DRP1, Caspase3, and Casapase9 proteins in the brain tissue of ACOP rats. These findings suggest that network pharmacology is a useful tool for traditional Chinese medicine (TCM) research, SFN can effectively inhibit apoptosis, protect cortical neurons from the toxicity of carbon monoxide through activating the AMPK pathway and may become a potential therapeutic strategy for brain injury after ACOP.

Bone marrow mesenchymal stem cells-derived exosomes mediated delivery of tetramethylpyrazine attenuate cerebral ischemic injury

ObjectivesTetramethylpyrazine (TEP) can protect the brain from ischemic damage, but it has defects such as short half-life, fast absorption, wide distribution, and rapid elimination, which limits its application. Exosomes (Exos) have the property of loading drugs and transporting signal substances. Here, we elucidated the effect of TEP-loaded bone marrow mesenchymal stem cell (BMSC)-derived Exos (Exo-TEP) on cerebral ischemic injury. Materials and MethodsThe Exos were extracted by ultracentrifugation and TEP was loaded into the Exos by electroporation. Oxygen-glucose deprivation (OGD) induced-primary cortical neurons and middle cerebral artery occlusion (MCAO)-induced mouse models were used to determine the effect of Exo-TEP on cerebral ischemic injury in vitro and in vivo. ResultsExo-TEP exhibited a stable and sustained release pattern compared to free TEP. Exo-TEP treatment was more significant in improving OGD-mediated decrease in cell activity, as well as a elevation in apoptosis and ROS production in cortical neurons. In comparison with Exo and free TEP treatment, Exo-TEP treatment significantly improved pathological changes, shrunk cerebral infarction volume, as well reduced neurological deficit scores and neuronal apoptosis, and oxidative stress. ConclusionsExo-TEP was superior to free TEP in improving cerebral ischemic injury by reducing neuronal apoptosis and oxidative stress.

Urolithin A alleviates early brain injury after subarachnoid hemorrhage by regulating the AMPK/mTOR pathway-mediated autophagy

ObjectiveUnfavorable outcomes in patients with subarachnoid hemorrhage (SAH) are mainly attributed to early brain injury (EBI). Reduction of neuronal death can improve the prognosis in SAH patients. Autophagy and apoptosis are critical players in neuronal death. Urolithin A (UA) is a natural compound produced by gut bacteria from ingested ellagitannins and ellagic acid. Here, we detected the role of UA in EBI post-SAH. MethodsWe established an animal model of SAH in rats by endovascular perforation, with administration of UA, 3-methyladenine (3-MA) and Compound C. SAH grading, neurological function, brain water content, western blotting analysis of levels of proteins related to apoptosis, autophagy and pathways, blood-brain barrier (BBB) integrity, TUNEL staining, and immunofluorescence staining of LC3 were evaluated at 24h after SAH. ResultsSAH induction led to neurological dysfunctions, BBB disruption, and cerebral edema at 24h post-SAH in rats, which were relieved by UA. Additionally, cortical neuronal apoptosis in SAH rats was also attenuated by UA. Moreover, UA restored autophagy level in SAH rats. Mechanistically, UA activated the AMPK/mTOR pathway. Furthermore, inhibition of autophagy and AMPK limited UA-mediated protection against EBI post-SAH ConclusionUA alleviates neurological deficits, BBB permeability, and cerebral edema by inhibiting cortical neuronal apoptosis through regulating the AMPK/mTOR pathway-dependent autophagy in rats following SAH.

WITHDRAWN: Transcription factor EB (TFEB) promotes autophagy in early brain injury after subarachnoid hemorrhage in rats

Early brain injury (EBI) is responsible for devastating outcomes for patients with subarachnoid hemorrhage (SAH). Autophagy and apoptosis regulate the process of cell death. The transcription factor EB (TFEB) can increase autophagic flux by promoting autophagosome formation and autophagosome-lysosome fusion, and dysregulation of TFEB activity might induce the development of several diseases. However, the biological functions of TFEB in EBI post-SAH remain unknown. We established an animal model of SAH by modified endovascular perforation and a cellular model by treating primary cortical neurons with oxyhemoglobin (oxyHb). A recombinant adenovirus containing a shRNA targeting TFEB (adv-sh-TFEB) was used to knock down TFEB expression. Protein levels of TFEB, Bax, Bcl-2, cleaved caspase-3, LC3, and Beclin-1 were measured by western blotting and immunofluorescence staining. Neuronal apoptosis was assessed by flow cytometry and TUNEL staining. Short-term neurobehavioral functions were examined by modified Garcia and beam balance scores. Brain edema was determined through assessment of brain water content. TFEB was increased at the protein level in cellular and animal models of SAH. TFEB depletion attenuated the oxyHb-induced apoptosis of primary cortical neurons and autophagy. TFEB downregulation improved the short-term neurobehavioral functions and reduced brain edema after SAH and inhibited neuronal apoptosis in SAH rats. TFEB depletion improves short-term neurologic performance and reduces brain edema by preventing autophagy and apoptosis after SAH.

DUSP10 alleviates ischemic stroke-induced neuronal damage by restricting p38/JNK pathway

Neuronal apoptosis is considered one of the hallmarks of ischemic stroke. Dual specificity phosphatase 10 (DUSP10), a member of the dual-specificity phosphatase family, which is involved in the regulation of apoptosis process. This study aimed to investigate the effect of on apoptosis in primary cortical neurons exposed to oxygen-glucose deprivation and reoxygenation (OGD/R) and mice suffered from transient middle cerebral artery occlusion and reperfusion (MCAO/R). The results showed that DUSP10 overexpression improved survival and reduced apoptosis in neurons subjected to OGD/R, which was manifested by decreased apoptotic proteins (cleaved caspase 3 and bax) and TUNEL+ cells, as well as increased the anti-apoptotic protein (bcl-2). DUSP10 overexpression inhibited the p38/JNK signaling pathway after OGD/R treatment, whilst DUSP10 knockdown had opposite effects. In addition, the p38 inhibitor SB203580 or JNK inhibitor SP600125 attenuated the increased apoptosis of OGD/R-stimulated neurons treated with DUSP10 silencing. Consistently, DUSP10 knockdown exacerbated infarct volume in MCAO/R injury. The data of Nissl staining and TUNEL-NeuN double staining revealed that DUSP10 interference aggravated neuronal damage in the ischemic penumbra of mice. Furthermore, DUSP10 inhibition activated the p38/JNK axis accompanied by enhanced phosphorylation of p38 and JNK in vivo. In summary, DUSP10 is a neuroprotective agent against ischemic stroke-induced neuronal damage via suppressing the p38/JNK signaling pathway.

Inhibition of mTORC2 improves brain injury in epileptic rats by promoting chaperone-mediated autophagy

Epilepsy can seriously affect children's cognitive and behavioral development. The mechanistic target of rapamycin(mTOR) pathway plays an important role in neurodevelopment and epilepsy, but the mechanism of mechanistic target of rapamycin complex 2 (mTORC2) in epilepsy is still unclear. Here, we compared the similarities and differences of the mechanisms of action of mechanistic target of rapamycin complex 1 (mTORC1) and mTORC2 complex in the pathogenesis of epilepsy. Our research results show that the levels of apoptosis in cortical and hippocampal neurons were upregulated in epileptic rats (F = 32.15, 30.96; both P < 0.01), and epilepsy caused neuronal damage (F = 8.13, 9.43; both P < 0.01). The mTORC2-Akt pathway was activated in the cortex and hippocampus of epileptic rats. Inhibition of mTORC2 resulted in decreased levels of apoptosis and reduced neuronal damage in the cortex and hippocampus of epileptic rats. In the hippocampus, selective inhibition of mTORC2 increased lysosome-associated membrane protein 2 A (LAMP2A) protein expression compared with the control group, and the difference was statistically significant (F = 3.02, P < 0.05). Finally, we concluded that in the hippocampus, selective inhibition of mTORC2 can improve epileptic brain injury in rats by increasing chaperone-mediated autophagy (CMA) levels.

Protective role of hispolon and its derivatives against apoptosis in cortical neurons induced by electromagnetic radiation from 4G mobile phone.

Electromagnetic radiation (EMR) from wireless devices, particularly mobile phones, is a potentially growing public health concern. In this study, the neuronal effects of EMR on primary cortical neurons (PCNs) from neonatal rat cerebral cortex and the protective role of hispolon (HIS) and its derivatives were investigated as a measure of cranial exposure during mobile phone use.PCNs were isolated and cultured from day-old neonatal rats, then exposed for 2 h to EMR emitted by a mobile phone operating at a frequency of 2100 MHz with 1.6 W/Kg specific absorption rate (SAR) in call-answered mode treated with HIS and its derivatives. The induction of apoptosis through modulation of pro and anti-apoptotic genes via mitochondrial pathway and the protection by the test compounds was assessed. Pyrazole derivatives decreased apoptosis by modulating the levels of pro and anti-apoptotic genes by reducing the levels of reactive oxygen species (ROS) via mitochondrial damage, which was observed in the EMR exposed PCNs. The pyrazole compounds were found to have antioxidative and anti-apoptotic properties. Thus, the neuroprotective mechanisms of the pyrazole derivatives can be investigated further, which may make them appropriate as lead compounds in developing neuroprotective formulations.

Integrated transcriptomic and metabolomic analysis of cortical neurons reveals dysregulated lipid metabolism, enhanced glycolysis and activated HIF-1 signaling pathways in acute hypoxia

The brain is the main oxygen-consuming organ and is vulnerable to ischemic shock or insufficient blood perfusion. Brain hypoxia has a persistent and detrimental effect on resident neurons. Previous studies have identified alterations in genes and metabolites in ischemic brain shock by single omics, but the adaptive systems that neurons use to cope with hypoxia remain uncovered. In the present study, we constructed an acute hypoxia model and performed a multi-omics analysis from RNA-sequencing and liquid chromatography-mass spectrometry (LC-MS)-based metabolomics on exploring potentially differentially expressed genes (DEGs) and metabolites (DEMs) in primary cortical neurons under severe acute hypoxic conditions. The TUNEL assay showed acute hypoxia-induced apoptosis in cortical neurons. Omics analysis identified 564 DEGs and 46 DEMs categorized in the Kyoto encyclopedia of genes and genomes (KEGG) database. Integrative pathway analysis highlighted that dysregulated lipid metabolism, enhanced glycolysis, and activated HIF-1 signaling pathways could regulate neuron physiology and pathophysiology under hypoxia. These findings may help us understand the transcriptional and metabolic mechanisms by which cortical neurons respond to hypoxia and identify potential targets for neuron protection.

Taurine promotes axonal sprouting via Shh-mediated mitochondrial improvement in stroke.

Motor function is restored by axonal sprouting in ischemic stroke. Mitochondria play a crucial role in axonal sprouting. Taurine (TAU) is known to protect the brain against experimental stroke, but its role in axonal sprouting and the underlying mechanism are unclear. We evaluated the motor function of stroke mice using the rotarod test on days 7, 14, and 28. Immunocytochemistry with biotinylated dextran amine was used to detect axonal sprouting. We observed neurite outgrowth and cell apoptosis in cortical neurons under oxygen and glucose deprivation (OGD), respectively. Furthermore, we evaluated the mitochondrial function, adenosine triphosphate (ATP), mitochondrial DNA (mtDNA), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PCG-1α), transcription factor A of mitochondria (TFAM), protein patched homolog 1 (PTCH1), and cellular myelocytomatosis oncogene (c-Myc). TAU recovered the motor function and promoted axonal sprouting in ischemic mice. TAU restored the neuritogenesis ability of cortical neurons and reduced OGD-induced cell apoptosis. TAU also reduced reactive oxygen species, stabilized mitochondrial membrane potential, enhanced ATP and mtDNA content, increased the levels of PGC-1α, and TFAM, and restored the impaired levels of PTCH1, and c-Myc. Furthermore, these TAU-related effects could be blocked using an Shh inhibitor (cyclopamine). Taurine promoted axonal sprouting via Shh-mediated mitochondrial improvement in ischemic stroke.