Autophagic death of neural stem cells mediates chronic stress-induced decline of adult hippocampal neurogenesis and cognitive deficits

Molecular profiling of a rat model of vascular dementia: Evidences from proteomics, metabolomics and experimental validations

Decrease of cerebral blood flow is the primary cause of vascular dementia (VD), but its pathophysiological mechanisms are still not known. This study aims to profile the molecular changes of a rat model of VD induced by bilateral common carotid artery ligation. The Morris water maze and new object recognition tasks were used to test the cognitive function of rats. Hematoxylin and Eosin (HE) staining was used to detect pathological changes in the hippocampus. After confirming the model, proteomics was used to detect differentially expressed proteins in the hippocampus, and metabolomics was used to detect differential metabolites in rat serum. Thereafter, bioinformatics were used to integrate and analyze the potential molecular profile. The results showed that compared with the sham control group, the spatial and recognition memory of the rats were significantly reduced, and pathological changes were observed in the hippocampal CA1 region of the model group. Proteomic analysis suggested 206 differentially expressed proteins in the hippocampus of VD rats, with 117 proteins upregulated and 89 downregulated. Protein-protein interaction network analysis suggested that those differentially expressed proteins might play crucial roles in lipid metabolism, cell adhesion, intracellular transport, and signal transduction. Metabolomics analysis identified 103 differential metabolites, and comparison with the human metabolome database revealed 22 common metabolites, which predicted 265 potential targets. Afterwards, by intersecting the predicted results from metabolomics with the differentially expressed proteins from proteomics, we identified five potential targets, namely ACE, GABBR1, Rock1, Abcc1 and Mapk10. Furthermore, western blotting confirmed that compared with control group, hippocampal GABBR1 and Rock1 were enhanced in the model group. Together, this study showed the molecular profile of VD rats through a combination of proteomics, metabolomics, and experimental confirmation methods, offering crucial molecular targets for the diagnosis and treatment of VD.

Brief Pup Separation in Lactation Confers Stress Resistance with Increased Prolactin and Adult Hippocampal Neurogenesis in Postpartum C57BL/6J Dams

Prolactin (PRL) assumes a pivotal role during the postpartum phase, particularly within the hippocampus-a region densely populated with receptors for stress hormones, where stress significantly inhibits adult hippocampal neurogenesis (AHN). The reduction in neurogenesis is implicated in the pathogenesis of anxiety and depression. Mothers are at an increased risk of developing depression when exposed to chronic stress. Therefore, it is imperative to investigate the potential role of PRL in depression-like behaviors stemming from prolonged postpartum stress, and to explore any underlying mechanisms. Despite pup separation (PS) being a natural postpartum care practice, the impact of various PS methods on lactating dams remains uncertain. Lactating C57BL/6J mice, from postpartum day (PPD) 1 to PPD 21, underwent no PS (NPS), brief PS (15 min per day, PS15), or long PS (180 min per day, PS180), followed by 21 days of chronic restraint stress (CRS). Behavioral tests were conducted, and measurements included serum PRL concentration, PRL-R expression, and AHN in the hippocampus. Dams with CRS exhibited cognitive decline, depressive- and anxiety-like behaviors, and reduced PRL secretion, correlating with lower levels of AHN. PS15 dams displayed lower levels of depressive- and anxiety-like behaviors and cognitive decline compared to NPS and PS180 dams. Significantly, PS15 dams exhibited higher levels of AHN, PRL-R expression in the hippocampus, and serum PRL concentration. This study collectively reveals reduced serum PRL and AHN in dams with cognitive decline and depressive- and anxiety-like behaviors after CRS. Brief PS confers resistance to behavioral deficits after CRS, increasing serum PRL concentration and reversing AHN decrease in dams.

[MiRNA-103-3p promotes neural cell autophagy by activating Wnt/β-catenin signaling via targeting rab10 in a rat model of depression]

OBJECTIVE

To explore the neuroprotective role of Rab10 gene in depression and the mechanism mediating its effect.

METHODS

Forty-eight male SD rats were randomized into a control group and 3 chronic unpredictable mild stress (CUMS) groups (n=12). The rats in the latter 3 groups were subjected to injections of normal saline, an adeno-associated viral (AAV) vector, or a Rab10-overexpressing AAV vector in the lateral ventricle after CUMS modeling. The depressive behavioral changes of the rats were assessed using behavioral tests. The TargetScan database was used to predict the miRNA interacting with Rab10 and the binding sites. The interaction between miRNA-103-3p and Rab10 was investigated using dual-luciferase and radioimmunoprecipitation (RIP) assay. The effect of corticosterone treatment on PC12 cell viability was assessed with CCK-8 assay. In corticosterone-stimulated PC12 cells, the changes in BDNF, CREB, p62, Beclin-1, Wnt3a, Gsk3β, phosphorylated (p)-Gsk3β, and β-catenin protein expressions following transfection with the Rab10-overexpressing AAV vector and a miRNA-103-3p inhibitor, alone or in combination, were analyzed using qRT-PCR and Western blotting.

RESULTS

Injection of Rab10-overexpressing AVV vector into the lateral ventricle significantly improved depressive behaviors of CUMS rats. The mRNA and proteins expression of Rab10 were significantly down-regulated in the hippocampus of CUMS rats and in corticosteronestimulated PC12 cells. Bioinformatics analysis and the results of double luciferase and RIP experiments confirmed the targeting relationship between miRNA-103-3p and Rab10. In PC12 cells, overexpression of Rab10 or silencing miRNA-103-3p activated the Wnt/β-catenin signaling pathway, up-regulated the expressions of BDNF, CREB and Beclin-1, and down-regulated the expression of p62 protein; silencing Rab10 obviously blocked the effect of miRNA-103-3p inhibitor.

CONCLUSION

In mouse models of depression, miRNA-103-3p activates Wnt/β-catenin signaling via targeting rab10 to improve neural plasticity and promotes neural cell autophagy.

Carotid artery transplantation of brain endothelial cells enhances neuroprotection and neurorepair in ischaemic stroke rats

Brain microvascular endothelial cells (BMECs), an important component of the neurovascular unit, can promote angiogenesis and synaptic formation in ischaemic mice after brain parenchyma transplantation. Since the therapeutic efficacy of cell-based therapies depends on the extent of transplanted cell residence in the target tissue and cell migration ability, the delivery route has become a hot research topic. In this study, we investigated the effects of carotid artery transplantation of BMECs on neuronal injury, neurorepair, and neurological dysfunction in rats after cerebral ischaemic attack. Purified passage 1 endothelial cells (P1-BMECs) were prepared from mouse brain tissue. Adult rats were subjected to transient middle cerebral artery occlusion (MCAO) for 30 min. Then, the rats were treated with 5 × 105 P1-BMECs through carotid artery infusion or tail vein injection. We observed that carotid artery transplantation of BMECs produced more potent neuroprotective effects than caudal injection in MCAO rats, including reducing infarct size and alleviating neurological deficits in behavioural tests. Carotid artery-transplanted BMECs displayed a wider distribution in the ischaemic rat brain. Immunostaining for endothelial progenitor cells and the mature endothelial cell markers CD34 and RECA-1 showed that carotid artery transplantation of BMECs significantly increased angiogenesis. Carotid artery transplantation of BMECs significantly increased the number of surviving neurons, decreased the cerebral infarction volume, and alleviated neurological deficits. In addition, we found that carotid artery transplantation of BMECs significantly enhanced ischaemia-induced hippocampal neurogenesis, as measured by doublecortin (DCX) and Ki67 double staining within 2 weeks after ischaemic injury. We conclude that carotid artery transplantation of BMECs can promote cerebral angiogenesis, neurogenesis, and neurological function recovery in adult rats after ischaemic stroke. Our results suggest that carotid injection of BMECs may be a promising new approach for treating acute brain injuries.

Chronic academic stress improves attentional control: Behavioral and electrophysiological evidence

Background

Detecting and responding to target objects in the visual environment is a key factor in goal-directed behavior. Exposure to chronic stress often results in alterations of prefrontal cortex (PFC) function, which may impact PFC-dependent selective attention process. This study aimed to investigate the effect of chronic academic stress on attentional control process.

Method

Both the stress group and the control group performed an arrow-based version of the Eriksen Flanker task. Event-related potentials (ERP) were recorded while the participants performed the task.

Results

The behavioural results exhibited decreased Flanker RT effect for the stress group compared to the control group, suggesting a reduced interference under stress. The ERP results showed that stress group showed decreased frontal N2 but increased early P3 and late P3/LPC activities compared to the control group. These results suggest reduced conflict monitoring but increased conflict resolution process under stress.

Conclusions

The chronic academic stress improves attentional control by reducing the conflict monitoring and enhancing conflict resolution processes.

Nlrp6 protects from corticosterone-induced NSPC ferroptosis by modulating RIG-1/MAVS-mediated mitophagy

Hippocampal neural stem/progenitor cells (NSPCs) are highly vulnerable to different stress stimuli, resulting in adult neurogenesis decline and eventual cognitive defects. Our previous study demonstrated that NOD-like receptor family pyrin domain-containing 6 (Nlrp6) highly expressed in NSPCs played a critical role in sustaining hippocampal neurogenesis to resist stress-induced depression, but the underlying mechnistms are still unclear. Here, we found that Nlrp6 depletion led to cognitive defects and hippocampal NSPC loss in mice. RNA-sequencing analysis of the primary NSPCs revealed that Nlrp6 deficiency altered gene expression profiles of mitochondrial energy generation and ferroptotic process. Upon siNlrp6 transfection, as well as corticosterone (CORT) exposure, downregulation of Nlrp6 suppressed retinoic acid-inducible gene I (RIG-1)/mitochondrial antiviral signaling proteins (MAVS)-mediated autophagy, but drove NSPC ferroptotic death. More interesting, short chain fatty acids (SCFAs) upregulated Nlrp6 expression and promoted RIG-1/MAVS-mediated mitophagy, preventing CORT-induced NSPC ferroptosis. Our study further demonstrates that Nlrp6 should be a sensor for RIG-1/MAVS-mediated mitophagy and play a critical role in maintain mitochondrial homeostasis of hippocampal NSPCs. These results suggests that Nlrp6 should be a potential drug target to combat neurodegenerative diseases relative with chronic stress.

Primitive and Definitive Neural Precursor Cells Are Present in Human Cerebral Organoids

Activation of neural stem cells (NSCs) correlates with improved functional outcomes in mouse models of injury. In the murine brain, NSCs have been extensively characterized and comprise (1) primitive NSCs (pNSCs) and (2) definitive NSCs (dNSCs). pNSCs are the earliest cells in the NSC lineage giving rise to dNSCs in the embryonic and adult mouse brain. pNSCs are quiescent under baseline conditions and can be activated upon injury. Herein, we asked whether human pNSCs and dNSCs can be isolated during the maturation of human cerebral organoids (COs) and activated by drugs known to regulate mouse NSC behavior. We demonstrate that self-renewing, multipotent pNSC and dNSC populations are present in human COs and express genes previously characterized in mouse NSCs. The drug NWL283, an inhibitor of apoptosis, reduced cell death in COs but did not improve NSC survival. Metformin, a drug used to treat type II diabetes that is known to promote NSC activation in mice, was found to expand human NSC pools. Together, these findings are the first to identify and characterize human pNSCs, advancing our understanding of the human NSC lineage and highlighting drugs that enhance their activity.

Heat stress induces IL-1β and IL-18 overproduction via ROS-activated NLRP3 inflammasome: implication in neuroinflammation in mice with heat stroke

Heat stroke induced cerebral damage via neuroinflammation. This study aimed to approach whether heat stress would promote NOD-like receptor protein 3 (NLRP3) inflammasome via reactive oxygen species (ROS). The mice were randomly divided into the sham group, the heat stress group, and the heat stress + TEMPOL (ROS scavenger) group. And the NLRP3 -/- mice were applied and divided into the NLRP3 -/-  + sham group and the NLRP3 -/-  + heat stress group. Furthermore, the BV2 cells were divided into four groups following the intervention measures: the heat stress + TEMPOL group, the heat stress + Z-VAD-FMK (caspase-1 inhibitor) group, the heat stress group, and the control group. ROS levels were examined. The expression levels of NLRP3, caspase-1, IL-1β, and IL-18 were detected by western blotting and double immunofluorescence. We found that heat stress attack induced excessive ROS in microglia and subsequently activated NLRP3 inflammasome in both mice and BV2 cells. When ROS scavenged, the expression level of NLRP3 was downregulated. Furthermore, with NLRP3 inflammasome activation, the expression levels of caspase-1, IL-1β, and IL-18 were increased. In NLRP3 -/- mice, however, the caspase-1, IL-1β, and IL-18 were significantly declined. Further experiments showed that pretreatment of caspase-1 inhibitor decreased the expression levels of IL-1β and IL-18. These results suggest that heat stress attack caused neuroinflammation via excessive ROS activating the NLRP3 inflammasome in microglia cells.

Chronic unpredictable stress induces autophagic death of adult hippocampal neural stem cells

Chronic psychological stress is a critical factor for neurological complications like anxiety disorders, dementia, and depression. Our previous results show that chronic restraint stress causes cognitive deficits and mood dysregulation by inducing autophagic death of adult hippocampal neural stem cells (NSCs). However, it is unknown whether other models of psychological stress also induce autophagic death of adult hippocampal NSCs. Here, we show that chronic unpredictable stress (CUS) for 10 days impaired memory function and increased anxiety in mice. Immunohistochemical staining with SOX2 and KI67 revealed a significant reduction in the number of NSCs in the hippocampus following exposure to CUS. However, these deficits were prevented by NSC-specific, inducible conditional deletion of Atg7. These findings suggest that autophagic death of adult hippocampal NSCs is a critical pathogenic mechanism underlying stress-induced brain disorders.

Integrative analysis of microRNA-mediated mitochondrial dysfunction in hippocampal neural progenitor cell death in relation with Alzheimer's disease

Adult hippocampal neurogenesis plays a pivotal role in maintaining cognitive brain function. However, this process diminishes with age, particularly in patients with neurodegenerative disorders. While small, non-coding microRNAs (miRNAs) are crucial for hippocampal neural stem (HCN) cell maintenance, their involvement in neurodegenerative disorders remains unclear. This study aimed to elucidate the mechanisms through which miRNAs regulate HCN cell death and their potential involvement in neurodegenerative disorders. We performed a comprehensive microarray-based analysis to investigate changes in miRNA expression in insulin-deprived HCN cells as an in vitro model for cognitive impairment. miR-150-3p, miR-323-5p, and miR-370-3p, which increased significantly over time following insulin withdrawal, induced pronounced mitochondrial fission and dysfunction, ultimately leading to HCN cell death. These miRNAs collectively targeted the mitochondrial fusion protein OPA1, with miR-150-3p also targeting MFN2. Data-driven analyses of the hippocampi and brains of human subjects revealed significant reductions in OPA1 and MFN2 in patients with Alzheimer's disease (AD). Our results indicate that miR-150-3p, miR-323-5p, and miR-370-3p contribute to deficits in hippocampal neurogenesis by modulating mitochondrial dynamics. Our findings provide novel insight into the intricate connections between miRNA and mitochondrial dynamics, shedding light on their potential involvement in conditions characterized by deficits in hippocampal neurogenesis, such as AD. [BMB Reports 2024; 57(6): 281-286].

Curcumin Improves Neurogenesis in Alzheimer's Disease Mice via the Upregulation of Wnt/β-Catenin and BDNF

Adult neurogenesis in the dentate gyrus (DG) is impaired during Alzheimer's disease (AD) progression. Curcumin has been reported to reduce cell apoptosis and stimulate neurogenesis. This study aimed to investigate the influence of curcumin on adult neurogenesis in AD mice and its potential mechanism. Two-month-old male C57BL/6J mice were injected with soluble β-amyloid (Aβ1-42) using lateral ventricle stereolocalization to establish AD models. An immunofluorescence assay, including bromodeoxyuridine (BrdU), doublecortin (DCX), and neuron-specific nuclear antigen (NeuN), was used to detect hippocampal neurogenesis. Western blot and an enzyme-linked immunosorbent assay (ELISA) were used to test the expression of related proteins and the secretion of brain-derived neurotrophic factor (BDNF). A Morris water maze was used to detect the cognitive function of the mice. Our results showed that curcumin administration (100 mg/kg) rescued the impaired neurogenesis of Aβ1-42 mice, shown as enhanced BrdU+/DCX+ and BrdU+/NeuN+ cells in DG. In addition, curcumin regulated the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) -mediated glycogen synthase kinase-3β (GSK3β) /Wingless/Integrated (Wnt)/β-catenin pathway and cyclic adenosine monophosphate response element-binding protein (CREB)/BDNF in Aβ1-42 mice. Inhibiting Wnt/β-catenin and depriving BDNF could reverse both the upregulated neurogenesis and cognitive function of curcumin-treated Aβ1-42 mice. In conclusion, our study indicates that curcumin, through targeting PI3K/Akt, regulates GSK3β/Wnt/β-catenin and CREB/BDNF pathways, improving the adult neurogenesis of AD mice.

Gut bacteria-driven homovanillic acid alleviates depression by modulating synaptic integrity

The gut-brain axis is implicated in depression development, yet its underlying mechanism remains unclear. We observed depleted gut bacterial species, including Bifidobacterium longum and Roseburia intestinalis, and the neurotransmitter homovanillic acid (HVA) in individuals with depression and mouse depression models. Although R. intestinalis does not directly produce HVA, it enhances B. longum abundance, leading to HVA generation. This highlights a synergistic interaction among gut microbiota in regulating intestinal neurotransmitter production. Administering HVA, B. longum, or R. intestinalis to mouse models with chronic unpredictable mild stress (CUMS) and corticosterone (CORT)-induced depression significantly improved depressive symptoms. Mechanistically, HVA inhibited synaptic autophagic death by preventing excessive degradation of microtubule-associated protein 1 light chain 3 (LC3) and SQSTM1/p62 proteins, protecting hippocampal neurons' presynaptic membrane. These findings underscore the role of the gut microbial metabolism in modulating synaptic integrity and provide insights into potential novel treatment strategies for depression.

Recent advances in the crosstalk between the brain-derived neurotrophic factor and glucocorticoids

Brain-derived neurotrophic factor (BDNF), a key neurotrophin within the brain, by selectively activating the TrkB receptor, exerts multimodal effects on neurodevelopment, synaptic plasticity, cellular integrity and neural network dynamics. In parallel, glucocorticoids (GCs), vital steroid hormones, which are secreted by adrenal glands and rapidly diffused across the mammalian body (including the brain), activate two different groups of intracellular receptors, the mineralocorticoid and the glucocorticoid receptors, modulating a wide range of genomic, epigenomic and postgenomic events, also expressed in the neural tissue and implicated in neurodevelopment, synaptic plasticity, cellular homeostasis, cognitive and emotional processing. Recent research evidences indicate that these two major regulatory systems interact at various levels: they share common intracellular downstream pathways, GCs differentially regulate BDNF expression, under certain conditions BDNF antagonises the GC-induced effects on long-term potentiation, neuritic outgrowth and cellular death, while GCs regulate the intraneuronal transportation and the lysosomal degradation of BDNF. Currently, the BDNF-GC crosstalk features have been mainly studied in neurons, although initial findings show that this crosstalk could be equally important for other brain cell types, such as astrocytes. Elucidating the precise neurobiological significance of BDNF-GC interactions in a tempospatial manner, is crucial for understanding the subtleties of brain function and dysfunction, with implications for neurodegenerative and neuroinflammatory diseases, mood disorders and cognitive enhancement strategies.

Autophagy in neural stem cells and glia for brain health and diseases

Autophagy is a multifaceted cellular process that not only maintains the homeostatic and adaptive responses of the brain but is also dynamically involved in the regulation of neural cell generation, maturation, and survival. Autophagy facilities the utilization of energy and the microenvironment for developing neural stem cells. Autophagy arbitrates structural and functional remodeling during the cell differentiation process. Autophagy also plays an indispensable role in the maintenance of stemness and homeostasis in neural stem cells during essential brain physiology and also in the instigation and progression of diseases. Only recently, studies have begun to shed light on autophagy regulation in glia (microglia, astrocyte, and oligodendrocyte) in the brain. Glial cells have attained relatively less consideration despite their unquestioned influence on various aspects of neural development, synaptic function, brain metabolism, cellular debris clearing, and restoration of damaged or injured tissues. Thus, this review composes pertinent information regarding the involvement of autophagy in neural stem cells and glial regulation and the role of this connexion in normal brain functions, neurodevelopmental disorders, and neurodegenerative diseases. This review will provide insight into establishing a concrete strategic approach for investigating pathological mechanisms and developing therapies for brain diseases.

Protective effect of hygrolansamycin C against corticosterone-induced toxicity and oxidative stress-mediated via autophagy and the MAPK signaling pathway

BACKGROUND

Excessive stress, a major problem in modern societies, affects people of all ages worldwide. Corticosterone is one of the most abundant hormones secreted during stressful conditions and is associated with various dysfunctions in the body. In particular, we aimed to investigate the protective effects of hygrolansamycin C (HYGC) against corticosterone-induced cellular stress, a manifestation of excessive stress prevalent in contemporary societies.

METHODS

We isolated HYGC from Streptomyces sp. KCB17JA11 and subjected PC12 cells to corticosterone-induced stress. The effects of HYGC were assessed by measuring autophagy and the expression of mitogen-activated protein kinase (MAPK) phosphorylation-related genes. We used established cellular and molecular techniques to analyze protein levels and pathways.

RESULTS

HYGC effectively protected cells against corticosterone-induced injury. Specifically, it significantly reduced corticosterone-induced oxidative stress and inhibited the expression of autophagy-related proteins induced by corticosterone, which provided mechanistic insight into the protective effects of HYGC. At the signaling level, HYGC suppressed c-Jun N-terminal kinase and extracellular signal-regulated kinase phosphorylation and p38 activation.

CONCLUSIONS

HYGC is a promising candidate to counteract corticosterone-induced apoptosis and oxidative stress. Autophagy and MAPK pathway inhibition contribute to the protective effects of HYGC. Our findings highlight the potential of HYGC as a therapeutic agent for stress-related disorders and serve as a stepping stone for further exploration and development of stress management strategies.

Targeting autophagy to counteract neuroinflammation: A novel antidepressant strategy

Depression is a common disease that affects physical and mental health and imposes a considerable burden on afflicted individuals and their families worldwide. Depression is associated with a high rate of disability and suicide. It causes a severe decline in productivity and quality of life. Unfortunately, the pathophysiological mechanisms underlying depression have not been fully elucidated, and the risk of its treatment is still presented. Studies have shown that the expression of autophagic markers in the brain and peripheral inflammatory mediators are dysregulated in depression. Autophagy-related genes regulate the level of autophagy and change the inflammatory response in depression. Depression is related to several aspects of immunity. The regulation of the immune system and inflammation by autophagy may lead to the development or deterioration of mental disorders. This review highlights the role of autophagy and neuroinflammation in the pathophysiology of depression, sumaries the autophagy-targeting small moleculars, and discusses a novel therapeutic strategy based on anti-inflammatory mechanisms that target autophagy to treat the disease.

Evaluation of the Observational Associations and Shared Genetics Between Glaucoma With Depression and Anxiety

Purpose

Glaucoma, a leading cause of blindness worldwide, is suspected to exhibit a notable association with psychological disturbances. This study aimed to investigate epidemiological associations and explore shared genetic architecture between glaucoma and mental traits, including depression and anxiety.

Methods

Multivariable logistic regression and Cox proportional hazards regression models were employed to investigate longitudinal associations based on UK Biobank. A stepwise approach was used to explore the shared genetic architecture. First, linkage disequilibrium score regression inferred global genetic correlations. Second, MiXeR analysis quantified the number of shared causal variants. Third, specific shared loci were detected through conditional/conjunctional false discovery rate (condFDR/conjFDR) analysis and characterized for biological insights. Finally, two-sample Mendelian randomization (MR) was conducted to investigate bidirectional causal associations.

Results

Glaucoma was significantly associated with elevated risks of hospitalized depression (hazard ratio [HR] = 1.54; 95% confidence interval [CI], 1.01-2.34) and anxiety (HR = 2.61; 95% CI, 1.70-4.01) compared to healthy controls. Despite the absence of global genetic correlations, MiXeR analysis revealed 300 variants shared between glaucoma and depression, and 500 variants shared between glaucoma and anxiety. Subsequent condFDR/conjFDR analysis discovered 906 single-nucleotide polymorphisms (SNPs) jointly associated with glaucoma and depression and two associated with glaucoma and anxiety. The MR analysis did not support robust causal associations but indicated the existence of pleiotropic genetic variants influencing both glaucoma and depression.

Conclusions

Our study enhances the existing epidemiological evidence and underscores the polygenic overlap between glaucoma and mental traits. This observation suggests a correlation shaped by pleiotropic genetic variants rather than being indicative of direct causal relationships.

Neuronal Stem Cells from Late-Onset Alzheimer Patients Show Altered Regulation of Sirtuin 1 Depending on Apolipoprotein E Indicating Disturbed Stem Cell Plasticity

Late-onset Alzheimer's disease (AD) is a complex multifactorial disease. The greatest known risk factor for late-onset AD is the E4 allele of the apolipoprotein E (APOE), while increasing age is the greatest known non-genetic risk factor. The cell type-specific functions of neural stem cells (NSCs), in particular their stem cell plasticity, remain poorly explored in the context of AD pathology. Here, we describe a new model that employs late-onset AD patient-derived induced pluripotent stem cells (iPSCs) to generate NSCs and to examine the role played by APOE4 in the expression of aging markers such as sirtuin 1 (SIRT1) in comparison to healthy subjects carrying APOE3. The effect of aging was investigated by using iPSC-derived NSCs from old age subjects as healthy matched controls. Transcript and protein analysis revealed that genes were expressed differently in NSCs from late-onset AD patients, e.g., exhibiting reduced autophagy-related protein 7 (ATG7), phosphatase and tensin homolog (PTEN), and fibroblast growth factor 2 (FGF2). Since SIRT1 expression differed between APOE3 and APOE4 NSCs, the suppression of APOE function in NSCs also repressed the expression of SIRT1. However, the forced expression of APOE3 by plasmids did not recover differently expressed genes. The altered aging markers indicate decreased plasticity of NSCs. Our study provides a suitable in vitro model to investigate changes in human NSCs associated with aging, APOE4, and late-onset AD.

ULK1 confers neuroprotection by regulating microglial/macrophages activation after ischemic stroke

Microglial activation and autophagy play a critical role in the progression of ischemic stroke and contribute to the regulation of neuroinflammation. Unc-51-like kinase 1 (ULK1) is the primary autophagy kinase involved in autophagosome formation. However, the impact of ULK1 on neuroprotection and microglial activation after ischemic stroke remains unclear. In this study, we established a photothrombotic stroke model, and administered SBI-0206965 (SBI), an ULK1 inhibitor, and LYN-1604 hydrochloride (LYN), an ULK1 agonist, to modulate ULK1 activity in vivo. We assessed sensorimotor deficits, neuronal apoptosis, and microglial/macrophage activation to evaluate the neurofunctional outcome. Immunofluorescence results revealed ULK1 was primarily localized in the microglia of the infarct area following ischemia. Upregulating ULK1 through LYN treatment significantly reduced infarct volume, improved motor function, promoted the increase of anti-inflammatory microglia. In conclusion, ULK1 facilitated neuronal repair and promoted the formation of anti-inflammatory microglia pathway after ischemic injury.

Expression profiles of oviductal mRNAs and lncRNAs in the follicular phase and luteal phase of sheep (Ovis aries) with 2 fecundity gene (FecB) genotypes

FecB (also known as BMPR1B) is a crucial gene in sheep reproduction, which has a mutation (A746G) that was found to increase the ovulation rate and litter size. The FecB mutation is associated with reproductive endocrinology, such mutation can control external estrous characteristics and affect follicle-stimulating hormone during the estrous cycle. Previous researches showed that the FecB mutation can regulate the transcriptomic profiles in the reproductive-related tissues including hypothalamus, pituitary, and ovary during the estrous cycle of small-tailed Han (STH) sheep. However, little research has been reported on the correlation between FecB mutation and the estrous cycle in STH sheep oviduct. To investigate the coding and noncoding transcriptomic profiles involved in the estrous cycle and FecB in the sheep oviduct, RNA sequencing was performed to analyze the transcriptomic profiles of mRNAs and long noncoding RNAs (lncRNAs) in the oviduct during the estrous cycle of STH sheep with mutant (FecBBB) and wild-type (FecB++) genotypes. In total, 21,863 lncRNAs and 43,674 mRNAs were screened, the results showed that mRNAs had significantly higher expression levels than the lncRNAs, and the expression levels of these screened transcripts were lower in the follicular phase than they were in the luteal phase. Among them, the oviductal glycoprotein gene (OVGP1) had the highest expression level. In the comparison between the follicular and luteal phases, 57 differentially expressed (DE) lncRNAs and 637 DE mRNAs were detected, including FSTL5 mRNA and LNC_016628 lncRNA. In the comparison between the FecBBB and FecB++ genotypes, 26 DE lncRNAs and 421 DE mRNAs were detected, including EEF1D mRNA and LNC_006270 lncRNA. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis indicated that the DE mRNAs were enriched mainly in terms related to reproduction such as the tight junction, SAGA complex, ATP-binding cassette, nestin, and Hippo signaling pathway. The interaction network between DE lncRNAs and DE mRNAs indicated that LNC_018420 may be the key regulator in sheep oviduct. Together, our results can provide novel insights into the oviductal transcriptomic function against a FecB mutation background in sheep reproduction.

Lycopene Alleviates Chronic Stress-Induced Hippocampal Microglial Pyroptosis by Inhibiting the Cathepsin B/NLRP3 Signaling Pathway

Lycopene (LYC) exerts a strong neuroprotective and antipyroptotic effects. This study explored the effects and mechanisms of LYC on chronic stress-induced hippocampal microglial damage and depression-like behaviors. The caspase-1 inhibitor VX-765 attenuated chronic restrain stress (CRS)-induced hippocampal microglial pyroptosis and depression-like behaviors. Moreover, the alleviation of CRS-induced hippocampal microglial pyroptosis and depression-like behaviors by LYC was associated with the cathepsin B/NLRP3 pathway. In vitro, the caspase-1 inhibitor Z-YVAD-FMK alleviated pyroptosis in highly aggressively proliferating immortalized (HAPI) cells. Additionally, the alleviation of corticosterone-induced HAPI cell damage and pyroptosis by LYC was associated with the cathepsin B/NLRP3 pathway. Furthermore, the cathepsin B agonist pazopanib promoted HAPI cell pyroptosis, whereas LYC inhibited pazopanib-induced pyroptosis via the cathepsin B/NLRP3 pathway. Similarly, Z-YVAD-FMK inhibited pazopanib-induced HAPI cell pyroptosis. These results suggest that LYC alleviates chronic stress-induced hippocampal microglial pyroptosis via the cathepsin B/NLRP3 pathway inhibition. This study provides a new strategy for treating chronic stress encephalopathy.

Adult hippocampal neurogenesis: pharmacological mechanisms of antidepressant active ingredients in traditional Chinese medicine

Depression is characterized by prominent indicators and manifestations, such as anhedonia, which refers to the inability to experience pleasure, and persistent feelings of hopelessness. In clinical practice, the primary treatment approach involves the utilization of selective serotonin reuptake inhibitors (SSRIs) and related pharmacological interventions. Nevertheless, it is crucial to recognize that these agents are associated with significant adverse effects. Traditional Chinese medicine (TCM) adopts a multifaceted approach, targeting diverse components, multiple targets, and various channels of action. TCM has potential antidepressant effects. Anomalies in adult hippocampal neurogenesis (AHN) constitute a pivotal factor in the pathology of depression, with the regulation of AHN emerging as a potential key measure to intervene in the pathogenesis and progression of this condition. This comprehensive review presented an overview of the pharmacological mechanisms underlying the antidepressant effects of active ingredients found in TCM. Through examination of recent studies, we explored how these ingredients modulated AHN. Furthermore, we critically assessed the current limitations of research in this domain and proposed novel strategies for preclinical investigation and clinical applications in the treatment of depression in future.

Antidepressant pharmacological mechanisms: focusing on the regulation of autophagy

The core symptoms of depression are anhedonia and persistent hopelessness. Selective serotonin reuptake inhibitors (SSRIs) and their related medications are commonly used for clinical treatment, despite their significant adverse effects. Traditional Chinese medicine with its multiple targets, channels, and compounds, exhibit immense potential in treating depression. Autophagy, a vital process in depression pathology, has emerged as a promising target for intervention. This review summarized the pharmacological mechanisms of antidepressants by regulating autophagy. We presented insights from recent studies, discussed current research limitations, and proposed new strategies for basic research and their clinical application in depression.

N-palmitoylethanolamine modulates hippocampal neuroplasticity in rats with stress-induced depressive behavior phenotype

Bioactive lipid mediator N-palmitoylethanolamide (PEA) is an endocannabinoid-like molecule. Based on our previous data, this study aimed to further investigate the antidepressant property of PEA via the peroxisome proliferator-activated receptor alpha (PPARα) pathway, focusing on the intervention of PEA on hippocampal neuroplasticity. Behavioral tests were performed in rats induced by unpredictable chronic mild stress (uCMS) in the last week of the experiment, and then the brain tissue samples were retained for subsequent immunohistochemical detection and Western blot analysis. In vitro, the apoptosis of HT22 cells induced by CORT and apoptosis-related proteins were detected by Hoechst staining and Western blot, respectively. The results showed that PEA ameliorated the depression-like phenotype in rats induced by uCMS, prevented the uCMS-induced reduction in the number of BrdU-positive cells, and increased BrdU/NeuN co-localization in the hippocampus, and upregulated the levels of synapse associated protein NCAM, MAP2, SYN and PSD95 in the hippocampus. Hoechst staining results showed that PEA significantly increased the CORT-induced reduction in the number of hippocampal neurons. Western blot analysis showed that PEA decreased the expression of caspase-3 and c-caspase-3, and increased the ratio of Bcl-2/Bax in CORT-induced HT22 cells. MK886, a PPARα antagonist, partially or completely reversed these effects. In conclusion, the therapeutic potential of PEA for depressive mood disorders may be through targeting the hippocampal neuroplasticity, including increasing adult neurogenesis and synaptic plasticity, as well as down-regulated neuronal apoptosis, to remodel hippocampal circuitries upon functional integration and PPARα pathway may be involved in this process.

The Role of the Adrenal-Gut-Brain Axis on Comorbid Depressive Disorder Development in Diabetes

Diabetic patients are more affected by depression than non-diabetics, and this is related to greater treatment resistance and associated with poorer outcomes. This increase in the prevalence of depression in diabetics is also related to hyperglycemia and hypercortisolism. In diabetics, the hyperactivity of the HPA axis occurs in parallel to gut dysbiosis, weakness of the intestinal permeability barrier, and high bacterial-product translocation into the bloodstream. Diabetes also induces an increase in the permeability of the blood-brain barrier (BBB) and Toll-like receptor 4 (TLR4) expression in the hippocampus. Furthermore, lipopolysaccharide (LPS)-induced depression behaviors and neuroinflammation are exacerbated in diabetic mice. In this context, we propose here that hypercortisolism, in association with gut dysbiosis, leads to an exacerbation of hippocampal neuroinflammation, glutamatergic transmission, and neuronal apoptosis, leading to the development and aggravation of depression and to resistance to treatment of this mood disorder in diabetic patients.

Ocular and neural genes jointly regulate the visuospatial working memory in ADHD children

OBJECTIVE

Working memory (WM) deficits have frequently been linked to attention deficit hyperactivity disorder (ADHD). Despite previous studies suggested its high heritability, its genetic basis, especially in ADHD, remains unclear. The current study aimed to comprehensively explore the genetic basis of visual-spatial working memory (VSWM) in ADHD using wide-ranging genetic analyses.

METHODS

The current study recruited a cohort consisted of 802 ADHD individuals, all met DSM-IV ADHD diagnostic criteria. VSWM was assessed by Rey-Osterrieth complex figure test (RCFT), which is a widely used psychological test include four memory indexes: detail delayed (DD), structure delayed (SD), structure immediate (SI), detail immediate (DI). Genetic analyses were conducted at the single nucleotide polymorphism (SNP), gene, pathway, polygenic and protein network levels. Polygenic Risk Scores (PRS) were based on summary statistics of various psychiatric disorders, including ADHD, autism spectrum disorder (ASD), major depressive disorder (MDD), schizophrenia (SCZ), obsessive compulsive disorders (OCD), and substance use disorder (SUD).

RESULTS

Analyses at the single-marker level did not yield significant results (5E-08). However, the potential signals with P values less than E-05 and their mapped genes suggested the regulation of VSWM involved both ocular and neural system related genes, moreover, ADHD-related genes were also involved. The gene-based analysis found RAB11FIP1, whose encoded protein modulates several neurodevelopment processes and visual system, as significantly associated with DD scores (P = 1.96E-06, Padj = 0.036). Candidate pathway enrichment analyses (N = 53) found that forebrain neuron fate commitment significantly enriched in DD (P = 4.78E-04, Padj = 0.025), and dopamine transport enriched in SD (P = 5.90E-04, Padj = 0.031). We also observed a significant negative relationship between DD scores and ADHD PRS scores (P = 0.0025, Empirical P = 0.048).

CONCLUSIONS

Our results emphasized the joint contribution of ocular and neural genes in regulating VSWM. The study reveals a shared genetic basis between ADHD and VSWM, with GWAS indicating the involvement of ADHD-related genes in VSWM. Additionally, the PRS analysis identifies a significant relationship between ADHD-PRS and DD scores. Overall, our findings shed light on the genetic basis of VSWM deficits in ADHD, and may have important implications for future research and clinical practice.

Spautin-1 Protects Against Mild TBI-Induced Anxiety-Like Behavior in Mice via Immunologically Silent Apoptosis

Anxiety is reportedly one of the most common mental changes after traumatic brain injury (TBI). Perineuronal nets (PNNs) produced by astrocytes in the lateral hypothalamus (LHA) that surround gamma-aminobutyric acid-ergic (GABAergic) neurons have been associated with anxiety. The potent anti-tumor effects of Spautin-1, a novel autophagy inhibitor, have been documented in malignant melanoma; moreover, the inhibition of autophagy is reported to mitigate anxiety disorders. However, little is known about the ability of spautin-1 to alleviate anxiety. In this study, we sought to investigate whether spautin-1 could alleviate anxiety-like behaviors post-TBI by reducing the loss of PNNs in the LHA. A mild TBI was established in mice through Feeney's weight-drop model. Then, Spautin-1 (20 mmol/2 μl) was immediately administered into the left lateral ventricle. Behavioral and pathological changes were assessed at 24 h, 7 days, 30 days, 31 days and 32 days after TBI by the neurological severity scores (NSS), open field test (OFT), elevated plus-maze (EPM) test, western blot, immunofluorescence assays and electron microscopy. Spautin-1 significantly reversed TBI-induced decreased time in the central zone during OFT and in the open-arm during the EPM test. Spautin-1 also increased PNNs around GABAergic neurons indicated by WFA- plus GAD2- positive A2-type astrocytes and attenuated M1-type microglia in the LHA 32 days after TBI compared to TBI alone. Moreover, compared to mice that only underwent TBI, spautin-1 downregulated autophagic vacuoles, abnormal organelles, the expression of Beclin 1, USP13, phospho-TBK1, and phospho-IRF3 and upregulated the levels of cleaved caspase-3, -7 and -9, but failed to increase TUNEL-positive cells in the LHA at 24 h. Spautin-1 alleviated anxiety-like behavior in mice exposed to mild TBI; this protective mechanism may be associated with decreased PNNs loss around GABAergic neurons via immunologically silent apoptosis induced by the caspase cascade.

Social defeat stress induces genome-wide 5mC and 5hmC alterations in the mouse brain

Stress is adverse experience that require constant adaptation to reduce the emotional and physiological burden, or "allostatic load", of an individual. Despite their everyday occurrence, a subpopulation of individuals is more susceptible to stressors, while others remain resilient with unknown molecular signatures. In this study, we investigated the contribution of the DNA modifications, 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC), underlying the individual differences in stress susceptibility and resilience. Genome-wide 5mC and 5hmC profiles from 3- and 6-month adult male mice that underwent various durations of social defeat were generated. In 3-month animals, 5mC and 5hmC work in parallel and do not distinguish between stress-susceptible and resilient phenotypes, while in 6-month animals, 5mC and 5hmC show distinct enrichment patterns. Acute stress responses may epigenetically "prime" the animals to either increase or decrease their predisposition to depression susceptibility. In support of this, re-exposure studies reveal that the enduring effects of social defeat affect differential biological processes between susceptible and resilient animals. Finally, the stress-induced 5mC and 5hmC fluctuations across the acute-chronic-longitudinal time course demonstrate that the negative outcomes of chronic stress do not discriminate between susceptible and resilient animals. However, resilience is more associated with neuroprotective processes while susceptibility is linked to neurodegenerative processes. Furthermore, 5mC appears to be responsible for acute stress response, whereas 5hmC may function as a persistent and stable modification in response to stress. Our study broadens the scope of previous research offering a comprehensive analysis of the role of DNA modifications in stress-induced depression.

3-Methyladenine ameliorates surgery-induced anxiety-like behaviors in aged mice by inhibiting autophagy-induced excessive oxidative stress

BACKGROUND

Postoperative anxiety is a common surgical complication in older patients. Research has recently linked excessive autophagy to several neurological disorders, including anxiety. This study aimed to determine whether 3-Methyladenine (3-MA) administration reduced anxiety-like behaviors in a mouse model following abdominal exploratory laparotomy.

METHODS

An abdominal exploratory laparotomy model of postoperative anxiety was established using male C57BL/6 mice aged 20 months. 3-MA (6, 30, and 150 mg/ml) was administered via intracerebroventricular immediately following surgery. The mice were assessed 14 days after surgery using the marble burying, elevated plus maze tests, and local field potential recording in the amygdala. The levels of expression of phosphorylated-Akt, Beclin-1, LC3B, nuclear factor erythroid 2-related factor 2 (Nrf2)-occupied regions in NeuN-positive cells, superoxide dismutase (SOD) activity, malondialdehyde (MDA), and glutathione (GSH) were measured at 24 h after surgery.

RESULTS

The injection of 3-MA reversed the increased number of marbles buried, decreased time spent in the open arm, and enhanced θ oscillation power after 14 days of abdominal exploratory laparotomy. In addition, administration of 3-MA reduced the ratio of phosphorylated- to total-Akt, decreased expression in Beclin-1 and LC3B, attenuated MDA levels, and increased the ratio of Nrf2-occupied areas in NeuN-positive cells, SOD activity, and GSH levels under abdominal exploratory laparotomy conditions.

CONCLUSIONS

3-MA improved anxiety-like behaviors in aged mice undergoing abdominal exploratory laparotomy by inhibiting excessive autophagy-induced oxidative stress. These results suggest that 3-MA could be an effective treatment for postoperative anxiety.

Chronic early life stress alters the neuroimmune profile and functioning of the developing zebrafish gut

Chronic early life stress (ELS) potently impacts the developing central nervous and immune systems and is associated with the onset of gastrointestinal disease in humans. Though the gut-brain axis is appreciated to be a major target of the stress response, the underlying mechanisms linking ELS to gut dysfunction later in life is incompletely understood. Zebrafish are a powerful model validated for stress research and have emerged as an important tool in delineating neuroimmune mechanisms in the developing gut. Here, we developed a novel model of ELS and utilized a comparative transcriptomics approach to assess how chronic ELS modulated expression of neuroimmune genes in the developing gut and brain. Zebrafish exposed to ELS throughout larval development exhibited anxiety-like behavior and altered expression of neuroimmune genes in a time- and tissue-dependent manner. Further, the altered gut neuroimmune profile, which included increased expression of genes associated with neuronal modulation, correlated with a reduction in enteric neuronal density and delayed gut transit. Together, these findings provide insights into the mechanisms linking ELS with gastrointestinal dysfunction and highlight the zebrafish model organism as a valuable tool in uncovering how "the body keeps the score."

Regulatory Molecules of Synaptic Plasticity in Anxiety Disorder

Synaptic plasticity is the capacity of synaptic transmission between neurons to be strengthened or weakened. There are many signal molecules accumulated in the presynaptic and postsynaptic membranes that can lead to the regulation of synaptic plasticity and involvement in numerous of neurological and psychiatric diseases, including anxiety disorder. However, the regulatory mechanisms of synaptic plasticity in the development of anxiety disorder have not been well summarized. This review mainly aims to discuss the biological functions and mechanisms of synaptic plasticity-related molecules in anxiety disorder, with a particular focus on the metabotropic glutamate receptors, brain-derived neurotrophic factor, hyperpolarization-activated cyclic nucleotide-gated channels, and postsynaptic density 95. The summarized functions and mechanisms of synaptic plasticity-related molecules in anxiety will provide insight into novel neuroplasticity modifications for targeted therapy for anxiety.

Morroniside inhibits Beclin1-dependent autophagic death and Bax-dependent apoptosis in cardiomyocytes through repressing BCL2 phosphorylation

Morroniside can prevent myocardial injury caused by ischemia and hypoxia, which can be used to treat acute myocardial infarction (AMI). Hypoxia can cause apoptosis and autophagic death of cardiomyocytes. Morroniside has the ability to inhibit apoptosis and autophagy. However, the relationship between Morroniside-protected cardiomyocytes and two forms of death is unclear. The effects of Morroniside on the proliferation, apoptosis level, and autophagic activity of rat cardiomyocyte line H9c2 under hypoxia were first observed. Next, the roles of Morroniside in the phosphorylation of JNK and BCL2, BCL2-Beclin1, and BCL2-Bax complexes as well as mitochondrial membrane potential in H9c2 cells were evaluated upon hypoxia. Finally, the significance of BCL2 or JNK in Morroniside-regulated autophagy, apoptosis, and proliferation in H9c2 cells was assessed by combining Morroniside and BCL2 competitive inhibitor (ABT-737) or JNK activator (Anisomycin). Our results showed that hypoxia promoted autophagy and apoptosis of H9c2 cells, and inhibited their proliferation. However, Morroniside could block the effect of hypoxia on H9c2 cells. In addition, Morroniside could inhibit JNK phosphorylation, BCL2 phosphorylation at the Ser70 and Ser87 sites, and the dissociation of BCL2-Beclin1 and BCL2-Bax complexes in H9c2 cells upon hypoxia. Moreover, the reduction of mitochondrial membrane potential in H9c2 cells caused by hypoxia was improved by Morroniside administration. Importantly, the inhibited autophagy, apoptosis, and promoted proliferation in H9c2 cells by Morroniside were reversed by the application of ABT-737 or Anisomycin. Overall, Morroniside inhibits Beclin1-dependent autophagic death and Bax-dependent apoptosis via JNK-mediated BCL2 phosphorylation, thereby improving the survival of cardiomyocytes under hypoxia.

Distinct Signaling Pathways for Autophagy-Driven Cell Death and Survival in Adult Hippocampal Neural Stem Cells

Autophagy is a cellular catabolic process that degrades and recycles cellular materials. Autophagy is considered to be beneficial to the cell and organism by preventing the accumulation of toxic protein aggregates, removing damaged organelles, and providing bioenergetic substrates that are necessary for survival. However, autophagy can also cause cell death depending on cellular contexts. Yet, little is known about the signaling pathways that differentially regulate the opposite outcomes of autophagy. We have previously reported that insulin withdrawal (IW) or corticosterone (CORT) induces autophagic cell death (ACD) in adult hippocampal neural stem (HCN) cells. On the other hand, metabolic stresses caused by 2-deoxy-D-glucose (2DG) and glucose-low (GL) induce autophagy without death in HCN cells. Rather, we found that 2DG-induced autophagy was cytoprotective. By comparing IW and CORT conditions with 2DG treatment, we revealed that ERK and JNK are involved with 2DG-induced protective autophagy, whereas GSK-3β regulates death-inducing autophagy. These data suggest that cell death and survival-promoting autophagy undergo differential regulation with distinct signaling pathways in HCN cells.

Tibial fracture surgery in elderly mice caused postoperative neurocognitive disorder via SOX2OT lncRNA in the hippocampus

Increasing evidence indicates the major role of mitochondrial function in neurodegenerative disease. However, it is unclear whether mitochondrial dynamics directly affect postoperative neurocognitive disorder (PND). This study aimed to analyze the underlying mechanisms of mitochondrial dynamics in the pathogenesis of PND. Tibial fracture surgery was performed in elderly mice to generate a PND model in vivo. Cognitive behavior was evaluated 3 days post-surgery using novel object recognition and fear conditioning. A gradual increase in the SOX2OT mRNA level and decrease in the SOX2 mRNA level were noted, with impaired cognitive function, in the mice 3 days after tibial surgery compared with mice in the sham group. To evaluate the role of SOX2OT in PND, SOX2OT knockdown was performed in vitro and in vivo using lentivirus transfection in HT22 cells and via brain stereotactic injection of lentivirus, respectively. SOX2OT knockdown reduced apoptosis, inhibited oxidative stress, suppressed mitochondrial hyperdivision, attenuated surgery-induced cognitive dysfunction, and promoted downstream SOX2 expression in elderly mice. Furthermore, Sox2 alleviated mitochondrial functional damage by inhibiting the transcription of mitochondrial division protein Drp1. Our study findings indicate that SOX2OT knockout alleviates surgery-induced mitochondrial fission and cognitive function defects by upregulating the expression of Sox2 in mice, resulting in the inhibition of drp1 transcription. Therefore, regulation of the SOX2/Drp1 pathway may be a potential mechanism for the treatment of patients with PND.

Regulation of Autophagy via Carbohydrate and Lipid Metabolism in Cancer

Metabolic changes are an important component of tumor cell progression. Tumor cells adapt to environmental stresses via changes to carbohydrate and lipid metabolism. Autophagy, a physiological process in mammalian cells that digests damaged organelles and misfolded proteins via lysosomal degradation, is closely associated with metabolism in mammalian cells, acting as a meter of cellular ATP levels. In this review, we discuss the changes in glycolytic and lipid biosynthetic pathways in mammalian cells and their impact on carcinogenesis via the autophagy pathway. In addition, we discuss the impact of these metabolic pathways on autophagy in lung cancer.

Astragaloside IV: A promising natural neuroprotective agent for neurological disorders

Neurological disorders are characterized by high morbidity, disability, and mortality rates, which seriously threaten human health. However, clinically satisfactory agents for treatment are still currently lacking. Therefore, finding neuroprotective agents with minimum side effects and better efficacy is a challenge. Chinese herbal medicine, particularly natural preparations extracted from herbs or plants, has become an unparalleled resource for discovering new agent candidates. Astragali Radix is an important Qi tonic drug in traditional Chinese medicine and has a long medicinal history. As a natural medicine, it has a good prevention and treatment effect on neurological disorders. Here, the role and mechanism of astragaloside IV in the treatment of neurological disorders were evaluated and discussed through previous research results. Related information from major scientific databases, such as PubMed, MEDLINE, Web of Science, ScienceDirect, Embase, BIOSIS Previews, and the Cochrane Central Register of Controlled Trials and Cochrane Library, covering between 2001 and 2021 was compiled, using "Astragaloside IV" and "Neurological disorders," "Astragaloside IV," and "Neurodegenerative diseases" as reference terms. By summarizing previous research results, we found that astragaloside IV may play a neuroprotective role through various mechanisms: anti-inflammatory, anti-oxidative, anti-apoptotic protection of nerve cells and regulation of nerve growth factor, as well as by inhibiting neurodegeneration and promoting nerve regeneration. Astragaloside IV is a promising natural neuroprotective agent. By determining its pharmacological mechanism, astragaloside IV may be a new candidate drug for the treatment of neurological disorders.

Spautin-1 administration mitigates mild TBI-induced cognitive and memory dysfunction in mice via activation of caspase-3

BACKGROUND

Cognitive and memory dysfunction, a common sequela of traumatic brain injury (TBI), places a heavy social and economic burden on individuals, families, communities, and countries. Although the potent anti-tumor effects of spautin-1, a novel autophagy inhibitor, have been documented in malignant melanoma, little is known regarding its efficacy on alleviation of cognitive and memory dysfunction. Here, we describe the effect of spautin-1 administration on cognitive and memory impairment post-TBI, and reveal its underlying mechanism of action.

METHODS

We first induced mild TBI in mice through Feeney's weight-drop model, then immediately administered spautin-1 (10 mmol/μl, 2 μl) into the left lateral ventricle. Behavioral and pathological changes were assessed at 24 h, 7 and 30 days after TBI by analyzing neurological severity scores (NSS), novel objective recognition (NOR), Morris water maze (MWM) test, recording of local field potential (LFP), as well as western blot, and immunofluorescence assays.

RESULTS

Mild TBI not only reduced recognition index and times crossing platform, but also aggravated neuronal injury, including reduced MAP2, GAD2, VGlut2, and CHAT intensity. It also elevated activated microglia and CD86-occupied areas in TMEM119-positive cells, but suppressed θ, β, and γ oscillation power in the hippocampal CA1. However, spautin-1 administration significantly reversed these changes, whereas AC-DEVD-CHO an inhibitor of caspase-3 partially blocked the neuroprotective effects of spautin-1.

CONCLUSION

Spautin-1 administration mitigates mild TBI-induced cognitive and memory dysfunction in mice, potentially through activation of caspase-3.

Supt16 Haploinsufficiency Impairs PI3K/AKT/mTOR/Autophagy Pathway in Human Pluripotent Stem Cells Derived Neural Stem Cells

The maintenance of neural stem cells (NSCs) plays a critical role in neurodevelopment and has been implicated in neurodevelopmental disorders (NDDs). However, the underlying mechanisms linking defective human neural stem cell self-renewal to NDDs remain undetermined. Our previous study found that Supt16 haploinsufficiency causes cognitive and social behavior deficits by disrupting the stemness maintenance of NSCs in mice. However, its effects and underlying mechanisms have not been elucidated in human neural stem cells (hNSCs). Here, we generated Supt16^+/- induced pluripotent stem cells (iPSCs) and induced them into hNSCs. The results revealed that Supt16 heterozygous hNSCs exhibit impaired proliferation, cell cycle arrest, and increased apoptosis. As the RNA-seq analysis showed, Supt16 haploinsufficiency inhibited the PI3K/AKT/mTOR pathway, leading to rising autophagy, and further resulted in the dysregulated expression of multiple proteins related to cell proliferation and apoptotic process. Furthermore, the suppression of Supt16 heterozygous hNSC self-renewal caused by autophagy activation could be rescued by MHY1485 treatment or reproduced in rapamycin-treated hNSCs. Thus, our results showed that Supt16 was essential for hNSC self-renewal and its haploinsufficiency led to cell cycle arrest, impaired cell proliferation, and increased apoptosis of hNSCs by regulating the PI3K/AKT/mTOR/autophagy pathway. These provided a new insight to understand the causality between the Supt16 heterozygous NSCs and NDDs in humans.

Role of Rapamycin and 3-MA in oxidative damage of HLECs caused by two doses of UVB radiation

Background

This study compared the role of autophagy regulators Rapamycin and 3-MA in oxidative damage and apoptosis of human lens epithelial cells (HLECs) caused by two doses of Ultraviolet Radiation B (UVB).

Methods

HLECs were irradiated with UVB, and two doses of UVB damage models were constructed. After treatment with autophagy regulators, cell damage tests such as CCK-8, LDH activity, and Ros detection were performed. Western blotting was used to detect the levels of autophagy-related proteins and apoptosis-related proteins. Quantitative real-time PCR (RT-qPCR) was used to detect the mRNA leve of secondary antioxidant enzymes.Flow cytometry was used to examine cell viability and apoptosis. Finally, the proportion of autophagy and apoptosis was observed by electron microscope.

Results

Autophagy inhibitor 3-MA promoted oxidative damage and apoptosis of HLECs at low doses of UVB (5 mJ/cm2), which corresponds to 1.3 ​h of exposure to sunlight in human eyes. Under the high dose of UVB (50mJ/cm2), which is equivalent to 13 ​h of exposure to sunlight in human eyes, the autophagy inducer Rapamycin caused more extensive oxidative damage and apoptosis of HLECs. 3-MA was able to reduce this damage, indicating that moderate autophagy is necessary for HLECs to cope with mild oxidative stress. For high dose UVB-induced oxidative stress, the use of 3-MA inhibiting autophagy is more beneficial to reduce cell damage and apoptosis. The mechanisms include degradation of damaged organelles, regulation of the expression of antioxidant enzymes HO-1, NQO1, GCS and regulation of apoptosis-related proteins.

Conclusions

Autophagy played different roles in HLECs oxidative stress induced by two doses of UVB. It provides new ideas for reducing oxidative damage and apoptosis of HLECs to prevent or delay the progression of age-related cataract (ARC).

Male Stressed Mice Having Behavioral Control Exhibit Escalations in Dorsal Dentate Adult-Born Neurons and Spatial Memory

An escapable (ES)/inescapable stress (IS) paradigm was used to study whether behavioral control and repeated footshock stressors may affect adult neurogenesis and related cognitive function. Male stressed mice having behavioral control (ES) had a short-term escalation in dorsal dentate gyrus (DG) neurogenesis, while similarly stressed mice having no such control had unaltered neurogenesis as compared to control mice receiving no stressors. Paradoxically, ES and IS mice had comparable stress-induced corticosterone elevations throughout the stress regimen. Appetitive operant conditioning and forced running procedures were used to model learning and exercise effects in this escapable/inescapable paradigm. Further, conditioning and running procedures did not seem to affect the mice's corticosterone or short-term neurogenesis. ES and IS mice did not show noticeable long-term changes in their dorsal DG neurogenesis, gliogenesis, local neuronal density, apoptosis, autophagic flux, or heterotypic stress responses. ES mice were found to have a greater number of previously labeled and functionally integrated DG neurons as compared to IS and control mice 6 weeks after the conclusion of the stressor regimen. Likewise, ES mice outperformed IS and non-stressed control mice for the first two, but not the remaining two, trials in the object location task. Compared to non-stressed controls, temozolomide-treated ES and IS mice having a lower number of dorsal DG 6-week-old neurons display poor performance in their object location working memory. These results, taken together, prompt us to conclude that repeated stressors, albeit their corticosterone secretion-stimulating effect, do not necessary affect adult dorsal DG neurogenesis. Moreover, stressed animals having behavioral control may display adult neurogenesis escalation in the dorsal DG. Furthermore, the number of 6-week-old and functionally-integrated neurons in the dorsal DG seems to confer the quality of spatial location working memory. Finally, these 6-week-old, adult-born neurons seem to contribute spatial location memory in a use-dependent manner.

Hyperactive neuronal autophagy depletes BDNF and impairs adult hippocampal neurogenesis in a corticosterone-induced mouse model of depression

Background: Depression is a mental disorder that poses a serious threat to human health. Adult hippocampal neurogenesis (AHN) is closely associated with the efficacy of antidepressants. Chronic treatment with corticosterone (CORT), a well-validated pharmacological stressor, induces depressive-like behaviors and suppresses AHN in experimental animals. However, the possible mechanisms of chronic CORT action remain elusive. Methods: A chronic CORT treatment (0.1 mg/mL, drinking water for 4 weeks) was applied to prepare a mouse model of depression. Immunofluorescence was performed to analyze the hippocampal neurogenesis lineage, and immunoblotting, immunofluorescence, electron microscopy, and adeno-associated virus (AAV) expressing a pH-sensitive tandemly tagged light chain 3 (LC3) protein were used to analyze neuronal autophagy. AAV-hSyn-miR30-shRNA was used to knock down autophagy-related gene 5 (Atg5) expression in the neurons. Results: Chronic CORT induces depressive-like behaviors and decreases the expression of neuronal brain-derived neurotrophic factor (BDNF) in the dentate gyrus (DG) of the hippocampus in mice. Moreover, it markedly diminishes the proliferation of neural stem cells (NSCs), neural progenitor cells, and neuroblasts and impairs the survival and migration of newborn immature and mature neurons in the DG, which may be attributed to changes in the cell cycle kinetics and induction of NSCs apoptosis. Furthermore, chronic CORT induces hyperactive neuronal autophagy in the DG, possibly by increasing the expression of ATG5 and causing excess lysosomal degradation of BDNF in neurons. Notably, inhibiting hyperactive neuronal autophagy in the DG of mice by knocking down Atg5 in neurons using RNA interference reverses the decrease of neuronal BDNF expression, rescues AHN, and exerts antidepressant effects. Conclusion: Our findings reveal a neuronal autophagy-dependent mechanism that links chronic CORT to reduced neuronal BDNF levels, AHN suppression and depressive-like behavior in mice. In addition, our results provide insights for treating depression by targeting neuronal autophagy in the DG of the hippocampus.

Macroautophagy in quiescent and senescent cells: a pathway to longevity?

Cellular quiescence - reversible exit from the cell cycle - is an important feature of many cell types important for organismal health. Aging and cellular dysfunction compromise the survival and reactivation of quiescent cells over time. Studies suggest that autophagic processes and lysosomal function are critical to maintaining the function of quiescent cells, especially adult stem cells, throughout life. Findings also point to both pro-senescence and anti-senescence functions for macroautophagy depending on context. In this review, we will discuss these findings, unanswered questions on the role of macroautophagy and lysosomal function in quiescent and senescent cells, and the possibility for interventions that stimulate macroautophagy and lysosomes to promote quiescent cell function and tissue regeneration.

Anxiolytic effect of YangshenDingzhi granules: Integrated network pharmacology and hippocampal metabolomics

Anxiety disorder is one of the most common mental diseases. It is mainly characterized by a sudden, recurring but indescribable panic, fear, tension and/or anxiety. Yangshendingzhi granules (YSDZ) are widely used in the treatment of anxiety disorders, but its active ingredients and underlying mechanisms are not yet clear. This study integrates network pharmacology and metabolomics to investigate the potential mechanism of action of YSDZ in a rat model of anxiety. First, potential active ingredients and targets were screened by network pharmacology. Then, predictions were verified by molecular docking, molecular dynamics and western blotting. Metabolomics was used to identify differential metabolites and metabolic pathways. All results were integrated for a comprehensive analysis. Network pharmacology analysis found that Carotene, β-sitosterol, quercetin, Stigmasterol, and kaempferol in YSDZ exert anxiolytic effects mainly by acting on IL1β, GABRA1, PTGS1, ESR1, and TNF targets. Molecular docking results showed that all the affinities were lower than -5 kcal/mol, and the average affinities were -7.7764 kcal/mol. Molecular dynamics simulation results showed that RMSD was lower than 2.5 A, and the overall conformational changes of proteins were small, indicating that the small molecules formed stable complexes with proteins. The results of animal experiments showed that YSDZ exerts anxiolytic effects by regulating GABRA1 and TNF-α, ameliorating pathological damage in hippocampal CA1, and regulating metabolic pathways such as thiamine, cysteine and methionine metabolism, lysine biosynthesis and degradation. Altogether, we reveal multiple mechanisms through which YSDZ exerts its anti-anxiety effects, which may provide a reference for its clinical application and drug development.

Lead Exposure Induced Neural Stem Cells Death via Notch Signaling Pathway and Gut-Brain Axis

Numerous studies have examined the effects of lead (Pb) on cognitive ability. It is essential for the brain to maintain its functions through the differentiation of neural stem cells into various types of cells. Despite this, it remains unclear how Pb exposure affects neural stem cells and how it does, so the Pb-exposed mice were treated with the Notch inhibitor DAPT after we established the Pb exposure models. Neuronal stem cells and autophagy were assessed by immunofluorescence staining and western blot. The microbiota of the feces was also analyzed using the 16S rRNA amplicon sequencing technique. In this study, we found that Pb exposure caused neural injuries and deficits in neural stem cells, whereas DAPT rescued the damage. With DAPT, Pb-induced autophagy was partially reversed. Exposure to Pb also reduced inflammation and damaged gut barrier function. Furthermore, Pb exposure led to low bacterial diversity, an increase in pathogen abundance, and an unusual mode of interaction. Taken together, this study revealed that damages in neural stem cells contributed largely to cognitive impairment during Pb exposure, and this process was partially dependent on the Notch pathway and gut dysbiosis.

Effect of chronic stress on tumorigenesis and development

Chronic stress activates the sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal (HPA) axis to aggravates tumorigenesis and development. Although the importance of SNS and HPA in maintaining homeostasis has already attracted much attention, there is still a lot remained unknown about the molecular mechanisms by which chronic stress influence the occurrence and development of tumor. While some researches have already concluded the mechanisms underlying the effect of chronic stress on tumor, complicated processes of tumor progression resulted in effects of chronic stress on various stages of tumor remains elusive. In this reviews we concluded recent research progresses of chronic stress and its effects on premalignancy, tumorigenesis and tumor development, we comprehensively summarized the molecular mechanisms in between. And we highlight the available treatments and potential therapies for stressed patients with tumor.

Co-exposure of chronic stress and alumina nanoparticles aggravates hippocampal microglia pyroptosis by activating cathepsin B/NLRP3 signaling pathway

Combined exposure of chronic stress and alumina nanoparticles (AlNPs) aggravates hippocampal injury, but the pathogenesis is unevaluated. This study aimed to investigate the effect and mechanism of co-exposure to chronic stress and AlNPs on hippocampal microglia pyroptosis. In this study, chronic restraint stress (CRS) alone caused NLRP3-mediated hippocampal microglia pyroptosis, but AlNPs did not. Moreover, co-exposure to CRS and AlNPs exacerbated hippocampal microglia pyroptosis, resulting in more severe hippocampal damage and behavioral deficits in rats. Protein-protein interaction network predicted that cathepsin B was a potential regulatory protein of NLRP3. CRS up-regulated cathepsin B expression which had a more pronounced increase in co-exposure group. Whereas, caspase-1 inhibitor VX-765 alleviated hippocampal microglia pyroptosis and behavioral deficits in rats. Consistent with in vivo results, co-exposure of corticosterone and AlNPs aggravated NLRP3-mediated pyroptosis and cathepsin B expression in HAPI cells. Nevertheless, the pyroptosis of HAPI cells was inhibited by cathepsin B inhibitor CA-074Me and NLRP3 knockout, respectively. NLRP3 agonist nigericin failed to promote the pyroptosis of HAPI cells in the presence of cathepsin B inhibition. These results demonstrated that co-exposure to chronic stress and AlNPs could aggravate hippocampal microglia pyroptosis by activating cathepsin B/NLRP3 signaling pathway, resulting in hippocampal damage and behavioral deficits.

Salvianolic acid B alleviates comorbid pain in depression induced by chronic restraint stress through inhibiting GABAergic neuron excitation via an ERK-CREB-BDNF axis-dependent mechanism

Pain comorbid with depression occurred frequently in clinical settings. This study aims to explore the molecular mechanism underlying antidepressant and analgetic effect of salvianolic acid B (SalB) in comorbid pain in depression induced by chronic restraint stress (CRS), which associates with GABAergic neuron activation in the amygdala and the ERK-CREB-BDNF signaling pathway. The differentially expressed genes related to comorbid pain in CRS-induced depression were screened through bioinformatics analysis. After CRS treatment for 3 weeks, depression-like behaviors were developed in GAD2-tdT mice. The retrograde tracer cholera toxin B subunit combined with retrograde tracer CTB-488 was injected into the parafascicular nucleus of thalamus to project GABAergic neurons to observe the labeling of neurons in the whole brain. After treatment with SalB and ERK-CREB-BDNF signaling pathway inhibitor, CRS mice showed a variety of depression-like behaviors, accompanied by enhanced activity of GABAergic neurons in the amygdala projecting to parafascicular nucleus of thalamus. BDNF underexpression occurred in the CRS mice. Overexpressed BDNF activated ERK-CREB-BDNF signaling pathway to alleviate comorbid pain in CRS-induced depression. After intraperitoneal injection of SalB, the depression-like behaviors and pain threshold in CRS mice were alleviated, the effects of which could be eliminated by ERK-CREB-BDNF signaling pathway antagonist. Collectively, SalB inhibits the excitation of GABAergic neurons in the amygdala and activates the ERK-CREB-BDNF signaling pathway through the parafascicular nucleus of thalamus, whereby alleviating comorbid pain in CRS-induced depression in mice.