Apoptosis Of Neural Stem Cells Research Articles

Loss of SV2A promotes human neural stem cell apoptosis via p53 signaling

This study investigated the role of synaptic vesicle protein 2A (SV2A) in the regulation of human induced pluripotent stem cell-derived neural stem cells (NSCs). SV2A was highly expressed in NSCs. SV2A knockdown promotes apoptosis, which was associated with an upregulation of genes involved in p53 signaling as determined by transcriptome analysis. Treatment with the small molecule p53 inhibitor pifithrin-α reversed the promotion of NSC apoptosis induced by loss of SV2A. These results demonstrate that SV2A plays an important role in regulating NSC survival via the p53 signaling pathway.

20S-Protopanaxatriol improves cognitive function of Alzheimer's disease by promoting endogenous neurogenesis.

Neurogenesis in Alzheimer's disease (AD) is impaired, and thus promoting neurogenesis is a promising strategy for treating AD-related cognition impairment. Here, we found that 20S-protopanaxatriol (PPT) can alleviate cognitive deficits in an AlCl3-induced AD zebrafish model in Y and T maze tests and increase the HUC expression of the telencephalon. PPT promotes neural stem cell (NSC) line differentiation into neurons under AD condition. PPT significantly alleviated the apoptosis and cell cycle arrest of NSCs induced by amyloid-beta. Next, we investigated the molecular mechanism of PPT in treating AD by network pharmacology and molecular docking. PPT could target PIK3CA and PI3K/AKT signaling pathways. PPT significantly reversed the reduced expression level of PIK3CA (PI3K p110), p-PI3Kp85 and p-AKT of NSCs under AD condition. These results suggested that PPT alleviated the cognitive dysfunction of AD and promoted NSC proliferation and neurogenesis through the PI3K/AKT pathway. Therefore, PPT might be a potential candidate to treat AD-related cognitive decline via enhancing endogenous neurogenesis.

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.

A redox-reactive delivery system via neural stem cell nanoencapsulation enhances white matter regeneration in intracerebral hemorrhage mice.

Intracerebral hemorrhage (ICH) poses a great threat to human health because of its high mortality and morbidity. Neural stem cell (NSC) transplantation is promising for treating white matter injury following ICH to promote functional recovery. However, reactive oxygen species (ROS)-induced NSC apoptosis and uncontrolled differentiation hindered the effectiveness of the therapy. Herein, we developed a single-cell nanogel system by layer-by-layer (LbL) hydrogen bonding of gelatin and tannic acid (TA), which was modified with a boronic ester-based compound linking triiodothyronine (T3). In vitro, NSCs in nanogel were protected from ROS-induced apoptosis, with apoptotic signaling pathways downregulated. This process of ROS elimination by material shell synergistically triggered T3 release to induce NSC differentiation into oligodendrocytes. Furthermore, in animal studies, ICH mice receiving nanogels performed better in behavioral evaluation, neurological scaling, and open field tests. These animals exhibited enhanced differentiation of NSCs into oligodendrocytes and promoted white matter tract regeneration on Day 21 through activation of the αvβ3/PI3K/THRA pathway. Consequently, transplantation of LbL(T3) nanogels largely resolved two obstacles in NSC therapy synergistically: low survival and uncontrolled differentiation, enhancing white matter regeneration and behavioral performance of ICH mice. As expected, nanoencapsulation with synergistic effects would efficiently provide hosts with various biological benefits and minimize the difficulty in material fabrication, inspiring next-generation material design for tackling complicated pathological conditions.

Inhibition of miR-141-3p attenuates apoptosis of neural stem cells via targeting PBX1 to regulate PROK2 transcription in MCAO mice

ABSTRACT MicroRNA-141-3p (miR-141-3p) has been found to be altered in the brain following a stroke. Herein, we investigate the impact of miR-141-3p on the apoptosis of neural stem cells (NSCs) in mice with middle cerebral artery occlusion (MCAO) and the potential mechanisms involved. Eight-week-old mice were injected intracerebroventricularly with miR-141-3p, antagomir-141-3p, or agomir negative control 2 h before MCAO, and animal behavior tests and infraction volume measurements were performed 24 h later. MCAO-mediated brain injury and NSCs apoptosis were observed by H&E, TTC, and TUNEL staining. The expression of cleaved caspase-3 and Ki67 was detected by western blotting. The luciferase reporter assay proved that miR-141-3p in combination with its target gene PBX homeobox 1 (PBX1). Exogenous miR-141-3p (agomir-141-3p) treatment increased infraction volume and brain edema and damaged neurological functions compared to control mice. Agomir-141-3p increased miR-141-3p expression in brain tissue of mice with MCAO and suppressed PBX1 expression. The effects of the agomir-141-3p-induced apoptosis in NSCs treated with oxygen–glucose deprivation (OGD)/reoxygenation (R) were abolished by PBX1 overexpression. The results from UCSC and JASPAR database showed that prokineticin 2 (PROK2) was a transcription factor of PBX1. The expression of PROK2 was transcriptionally regulated by PBX1 using RT-PCR and western blot assays. The effects of the apoptosis-promoting caused by PBX1 inhibition in NSCs treated with OGD/R were reversed by PROK2 inhibition. In conclusion, the miR-141-3p/PBX1/PROK2 axis might be a novel therapeutic target for the apoptosis of NSCs in MCAO.

MFG-E8 Exerts Neuroprotection in Neural Stem Cells Induced by Anesthetic Sevoflurane via Regulating the PI3K/AKT Pathways.

MFG-E8 has shown tissue protection effects in various models of organ injury. In this study, the function of MFG-E8 in SEV-induced neural stem cells (NSCs) was studied. The cell viability and apoptosis affected by rhMFG-E8 were tested by MTT and flow cytometry analysis, respectively. Then, the mRNA expression of MFG-E8 was detected by qRT-PCR. The expression of SOD, GSF-Px, and MDA was assessed using ELISA assay. Western blot analysis was applied for assessing the expression of MFG-E8, BCL2, BAX, cleaved caspase-3, GRP-78, XBP-1, ATF-6, ATF-4, CHOP, p-PI3K, PI3K, p-AKT, and AKT. The pharmacological experiments suggested that both mRNA and protein expression of MFG-E8 were significantly decreased after 24 h, 48 h, and 72 h treatment with SEV, and the Western blot results displayed that 50 and 100 μg/ml rhMFG-E8 could evidently promote the expression of MFG-E8 in NSCs induced by SEV. Next, rhMFG-E8 reduced the apoptosis of NSCs induced by SEV through upregulating Bcl-2 and cleaved caspase-3 and downregulating Bax. Moreover, rhMFG-E8 alleviated the endoplasmic reticulum pressure of NSCs induced by SEV through decreasing the expression of GRP-78, XBP-1, ATF-6, ATF-4, and CHOP. In addition, the rhMFG-E8 could promote the expression of SOD and GSH-Px and inhibit the expression of MDA and LDH detected by the ELISA assay and LDH kit. Moreover, rhMFG-E8 elevated the expression of p-PI3K/PI3K and p-AKT/AKT, which were inhibited by SEV in NSCs. The results of this project supported that rhMFG-E8 protects neural activity in neural stem cells induced by anesthetic sevoflurane via regulating the PI3K/AKT pathways.

Resetting Proteostasis of CIRBP with ISRIB Suppresses Neural Stem Cell Apoptosis under Hypoxic Exposure.

Neurological disorders are often progressive and lead to disabilities with limited available therapies. Epidemiological evidence implicated that prolonged exposure to hypoxia leads to neurological damage and a plethora of complications. Neural stem cells (NSCs) are a promising tool for neurological damage therapy in terms of their unique properties. However, the literature on the outcome of NSCs exposed to severe hypoxia is scarce. In this study, we identified a responsive gene that reacts to multiple cellular stresses, marked cold-inducible RNA-binding protein (CIRBP), which could attenuate NSC apoptosis under hypoxic pressure. Interestingly, ISRIB, a small-molecule modulator of the PERK-ATF4 signaling pathway, could prevent the reduction and apoptosis of NSCs in two steps: enhancing the expression of CIRBP through the protein kinase R- (PKR-) like endoplasmic reticulum kinase (PERK) and activating transcription factor 4 (ATF4) axis. Taken together, CIRBP was found to be a critical factor that could protect NSCs against apoptosis induced by hypoxia, and ISRIB could be acted upstream of the axis and may be recruited as an open potential therapeutic strategy to prevent or treat hypoxia-induced brain hazards.

Lipid Microcapsules Promoted Neural Stem Cell Survival in the Infarcted Area of Mice with Ischemic Stroke by Inducing Autophagy.

Intracerebral transplantation of neural stem cells (NSCs) for ischemic stroke treatment has been demonstrated to be inefficient, with only <5% of delivered cells being retained. Microcapsules may be a good carrier for NSC delivery; however, the current microcapsules do not fully meet the demands for cell survival after transplantation. In the present study, we designed a strategy for the encapsulation of NSCs in a novel lipid-alginate (L-A) microcapsule based on a two-step method. The protective effect of a L-A microcapsule on oxygen-glucose deprivation (OGD) was investigated by using the CCK8 test, the LDH release test, and flow cytometry. Mechanisms underlying the prosurvival effect were investigated by detecting autophagy markers like P62, LC3-I, and LC3-II, and autophagy flux analysis was also performed. Lastly, the ability of the L-A microcapsule to support NSCs delivery for ischemic stroke was investigated in the middle cerebral artery occlusion (MCAO) model. We found that L-A microcapsules exerted a good protective effect against OGD compared with control and alginate microcapsules. The L-A microcapsules were found to promote cell survival by not only providing a "physical" barrier but also altering autophagy markers like P62 and LC3-II, which enhanced autophagy flux. This novel microcapsule was confirmed to be suitable for NSC delivery in vivo, which alleviated transplanted NSC apoptosis, reduced the infarct volume, decreased brain edema, improved neurological deficit scores, and lastly, improved survival rate. The findings of this study may provide a new method for stem cell delivery, raising the prospect that intracerebral cell transplantation may be used to treat, for instance, ischemic stroke, traumatic brain injury, and so on.

Hox genes collaborate with helix-loop-helix factor Grainyhead to promote neuroblast apoptosis along the anterior-posterior axis of the Drosophila larval central nervous system.

Hox genes code for a family of a homeodomain containing transcription factors that use TALE-HD containing factors Pbx/Exd and Meis/Homothorax to specify the development of the anterior-posterior axis of an organism. However, the absence of TALE-HD containing factors from specific tissues emphasizes the need to identify and validate new Hox cofactors. In Drosophila central nervous system, Hox executes segment-specific apoptosis of neural stem cells (neuroblasts) and neurons. In abdominal segments of larval central nervous system, Hox gene Abdominal-A mediates neuroblast apoptosis with the help of Extradenticle and bHLH factor Grainyhead using a 717-bp apoptotic enhancer. In this study, we show that this enhancer is critical for abdominal neuroblast apoptosis and relies on 2 separable set of DNA-binding motifs responsible for its initiation and maintenance. Our results also show that Abdominal-A and Grainyhead interact through their highly conserved DNA-binding domains, and the DNA-binding specificity of Abdominal-A-homeodomain is important for it to interact with Grainyhead and essential for it to execute neuroblast apoptosis in central nervous system. We also establish that Grainyhead is required for Hox-dependent neuroblast apoptosis in Labial and Sex Combs Reduced expressing regions of the central nervous system, and it can physically interact with all the Hox proteins in vitro. Our biochemical and functional data collectively support the idea that Grainyhead can function as a Hox cofactor and help them carry out their in vivo roles during development.

Upregulating microRNA‐210 to Inhibit Apoptosis of Neural Stem Cells with an MRI–Visible Nanomedicine for Stroke Therapy

Transplantation of neural stem cells (NSCs) is a promising paradigm for treating stroke. However, the poor survival of transplanted NSCs greatly limits the therapeutic potential. microRNA‐210 (miR‐210), a key hypoxia‐regulated miRNA, can enhance cell survival by targeting the expression of multiple apoptosis‐related genes, such as caspase‐8‐associated protein‐2 (casp8ap2), Bax, and Bcl‐2. Meanwhile, a noninvasive cell‐tracking method is also indispensable for monitoring the in vivo cell‐based therapy. Herein, an MRI–visible nanomedicine is developed to codeliver superparamagnetic iron oxide (SPIO) nanoparticles and miR‐210 into NSCs. This therapeutic nanomedicine not only promotes the survival of NSCs via upregulating miR‐210 to inhibit NSCs apoptosis but also allows an in vivo tracking of transplanted NSCs with MRI. The enhanced NSCs survivability significantly promotes the structural and functional recovery after stroke onset, which highlights the great potential of the multifunctional nanomedicine to improve the therapeutic efficacy of NSCs for stroke treatment.

Effect of Alpha and Beta Adrenergic Receptors on the Expression of Stk4, Caspase-3, and Sox2 Genes in Neural Stem Cells Derived From the Hippocampus and Treated With Norepinephrine in Rats

Background and Objectives Uncontrolled stress affects hippocampal-dependent memory through altering the morphology and the proliferation rate of hippocampal progenitor cells. Subjects and Methods In this experimental study, neural stem cells (NSCs) were isolated from the hippocampus of newborn rats and cultivated in a serum-free medium to generate neurosphere. To confirm the induced NSCs, immunocytochemistry and antibody nestin were used. The rate of cell proliferation and cytotoxicity caused by norepinephrine were measured by the MTT assay. NSCs were assigned in the following groups: Control (untreated NSCs), norepinephrine (NSCs treated with norepinephrine), propranolol (NSCs treated with beta receptor blocker propranolol plus norepinephrine), prazosin (NSCs treated with Alfa receptor blocker prazosin plus norepinephrine), and propranolol/ prazosin (NSCs treated with both propranolol and prazosin plus norepinephrine). Real-time PCR was conducted to measure the expression levels of Stk4, Caspase-3 and Sox2 genes. Results The flow cytometry study revealed that NSCs were nestin positive. Real-time PCR results showed that the expression level of Sox2 gene increased by norepinephrine. In addition, the expression level of Stk4 and Caspase-3 genes increased in the groups treated with prazosin. Conclusion The effect of norepinephrine on hippocampus-derived NSCs is receptor-dependent. The increase of norepinephrine under chronic stress can lead to either cell proliferation or apoptosis in NSCs; it acts as a double-edged sword.

Establishment of a system for regulating the gene expression of embryonic mouse cerebral cortex neural stem cells by in utero electroporation

To establish a system for regulating the gene expression of embryonic mouse cerebral cortex neural stem cells (NSCs) using in utero electroporation (IUE). At embryonic day 14.5, the mouse cerebral cortex NSCs were electro-transfected with the pCIG plasmid injected into the ventricle of the mouse embryo. At embryonic day 16.5 or day 17.5, embryonic mouse brain tissues were collected to prepare frozen sections. Immunofluorescence staining was used to observe the proliferation, apoptosis, division, directional differentiation, migration, and maturation of NSCs. The differentiation of NSCs into intermediate progenitors, the proliferation and apoptosis of NSCs, and the morphological development of radial axis of radial glial cells were observed at embryonic day 16.5. The differentiation of NSCs into neurons in layers V-VI of the cerebral cortex, the migration of NSCs to the lateral cerebral cortex, the development of dendrites of migrating neurons, and the maturation of neurons were observed at embryonic day 17.5. The system for regulating the gene expression of embryonic mouse cerebral cortex NSCs can be established using IUE, which is useful for the study of neural development related to the proliferation, apoptosis, division, directional differentiation, migration and maturation of NSCs in the cerebral cortex.

Propofol induces the apoptosis of neural stem cells via microRNA-9-5p / chemokine CXC receptor 4 signaling pathway

ABSTRACT Recent studies suggested that propofol, one of the most widely used anesthetics, may cause neurotoxicity in the developing brain, leading to cognitive deficits in adults. However, the underlying mechanisms remain unclear. In this study, we aimed to evaluate the mechanisms of propofol neurotoxicity in the neural stem cells (NSCs). The mRNA and protein expression levels of microRNA-9-5p (miR-9-5p) and chemokine CXC receptor 4 (CXCR4) were determined by quantitative reverse transcription-polymerase chain reaction and Western blotting analyses. Cell viability and apoptosis were evaluated using the cell counting kit-8 and Hoechst staining kits. The levels of apoptosis-related proteins B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein, and caspase-3 were detected by Western blotting analysis. These results confirmed that propofol activated cell apoptosis in a dose-dependent manner. A significant increase in the miR-9-5p and CXCR4 expression was observed in the propofol-treated cells. The overexpression of miR-9-5p induced apoptosis in NSCs, accompanied by elevated apoptosis-related protein activity. Furthermore, mitigated CXCR4 expression reduced propofol-induced cell apoptosis. We conclude that propofol induces cell death in NSCs, and overexpression of miR-9-5p/CXCR4 contributes to propofol-induced cell apoptosis, which might be a target for developing novel strategies to treat propofol neurotoxicity.

The Regulatory Effects of Taurine on Neurogenesis and Apoptosis of Neural Stem Cells in the Hippocampus of Rats.

The promotion of neurogenesis from neural stem cells (NSCs) in the hippocampus was found to be the most fundamental and effective therapy for depression. Our previous studies proved an antidepressive effect of taurine on rats, but the exact mechanism remains unclear. In this study, CUMS model was established in rats, and NSCs were cultured in vitro to investigate the protective effect and mechanisms of taurine on neurogenesis and apoptosis in CUMS rats and glutamate-injured NSCs. The results showed that ki67-positive cells were significantly increased by taurine, while apoptosis in the DG of CUMS rats was significantly inhibited by taurine. In vitro study, cell viability, Brdu+, β-tubulin III+, and GFAP+ cells in taurine-treated cells were significantly higher, while apoptosis rate was lower than the glutamate-treated cells. The protein expression of BDNF and its downstream pathway was upregulated by taurine administration. The results demonstrated that taurine can increase the survival, proliferation, and differentiation of NSCs; this protective effect of taurine may be due to the upregulation of BDNF/ERK/CREB signaling pathway. On the other hand, taurine can also inhibit abnormal apoptosis induced by CUMS or glutamate, the mechanism of which may be due to its antioxidative ability.

Recapitulating influenza virus infection and facilitating antiviral and neuroprotective screening in tractable brain organoids.

Human pluripotent stem cell derived brain organoids offer an unprecedented opportunity for various applications as in vitro model. Currently, human brain organoids as models have been used to understand virus-induced neurotoxicity.Methods: The brain organoids were separately challenged by multiple viruses including influenza viruses (H1N1-WSN and H3N2-HKT68), Enteroviruses (EV68 and EV71) and Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV) to investigate the impaired effect of these viruses on human brain development.Results: The brain organoids challenged by influenza viruses had decreased overall organoid size, while enteroviruses infected brain organoids displayed the opposite result. Then, we found WSN preferentially infected MAP2+ neurons compared to SOX2+ neural stem cells (NSCs) and GFAP+ astrocytes in brain organoids, and induced apoptosis of NSCs and neurons, and released inflammatory factors (TNF-α, INF-γ, and IL-6), facilitating brain damage. Furthermore, transcriptional profiling revealed several co-upregulated genes (CSAG3 and OAS2) and co-downregulated genes (CDC20B, KCNJ13, OTX2-AS1) after WSN infection for 24 hpi and 96 hpi, implicating target for antiviral drugs development. Finally, we explored compound PYC-12 could significantly suppress virus infection, apoptosis, and inflammatory responses.Conclusions: Collectively, we established a tractable experimental model to investigate the impact and mechanism of virus infection on human brain development.

Agonistic analog of growth hormone–releasing hormone promotes neurofunctional recovery and neural regeneration in ischemic stroke

Ischemic stroke can induce neurogenesis. However, most stroke-generated newborn neurons cannot survive. It has been shown that MR-409, a potent synthetic agonistic analog of growth hormone-releasing hormone (GHRH), can protect against some life-threatening pathological conditions by promoting cell proliferation and survival. The present study shows that long-term treatment with MR-409 (5 or 10 μg/mouse/d) by subcutaneous (s.c.) injection significantly reduces the mortality, ischemic insult, and hippocampal atrophy, and improves neurological functional recovery in mice operated on for transient middle cerebral artery occlusion (tMCAO). Besides, MR-409 can stimulate endogenous neurogenesis and improve the tMCAO-induced loss of neuroplasticity. MR-409 also enhances the proliferation and inhibits apoptosis of neural stem cells treated with oxygen and glucose deprivation-reperfusion. The neuroprotective effects of MR-409 are closely related to the activation of AKT/CREB and BDNF/TrkB pathways. In conclusion, the present study demonstrates that GHRH agonist MR-409 has remarkable neuroprotective effects through enhancing endogenous neurogenesis in cerebral ischemic mice.

Alleviating Oxidative Damage-Induced Telomere Attrition: a Potential Mechanism for Inhibition by Folic Acid of Apoptosis in Neural Stem Cells.

DNA oxidative damage can cause telomere attrition or dysfunction that triggers cell senescence and apoptosis. The hypothesis of this study is that folic acid decreases apoptosis in neural stem cells (NSCs) by preventing oxidative stress-induced telomere attrition. Primary cultures of NSCs were incubated for 9days with various concentrations of folic acid (0-40µM) and then incubated for 24h with a combination of folic acid and an oxidant (100-µM hydrogen peroxide, H2O2), antioxidant (10-mM N-acetyl-L-cysteine, NAC), or vehicle. Intracellular folate concentration, apoptosis rate, cell proliferative capacity, telomere length, telomeric DNA oxidative damage, telomerase activity, intracellular reactive oxygen species (ROS) levels, cellular oxidative damage, and intracellular antioxidant enzyme activities were determined. The results showed that folic acid deficiency in NSCs decreased intracellular folate concentration, cell proliferation, telomere length, and telomerase activity but increased apoptosis, telomeric DNA oxidative damage, and intracellular ROS levels. In contrast, folic acid supplementation dose-dependently increased intracellular folate concentration, cell proliferative capacity, telomere length, and telomerase activity but decreased apoptosis, telomeric DNA oxidative damage, and intracellular ROS levels. Exposure to H2O2 aggravated telomere attrition and oxidative damage, whereas NAC alleviated the latter. High doses of folic acid prevented telomere attrition and telomeric DNA oxidative damage by H2O2. In conclusion, inhibition of telomeric DNA oxidative damage and telomere attrition in NSCs may be potential mechanisms of inhibiting NSC apoptosis by folic acid.

P53 Inhibition Provides a Pivotal Protective Effect against Cerebral Ischemia-Reperfusion Injury via the Wnt Signaling Pathway

Introduction: Cerebral ischemia-reperfusion injury enhances brain injury and increases its morbidity and mortality. The purpose of our study was to further explore the specific pathogenesis of cerebral ischemia disease by studying the role of p53 in cerebral ischemia-reperfusion injury and its mechanism to provide a new target for the treatment of cerebral ischemia. Methods: Middle cerebral artery occlusion (MCAo) was established in rats. The changes in p53 and apoptotic proteins in the rat model were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. The effects of p53 inhibitors on cerebral is­chemia-reperfusion injury in rats were evaluated by modified neurological severity score (mNSS) and infarct area. Subsequently, neural stem cells (NSCs) were isolated and cultured in vitro, and oxygen and glucose deprivation (OGD) was induced to establish an in vitro ischemia-reperfusion injury model. Cell viability and migration were detected by CCK-8 and transwell assays. Apoptosis of NSCs was detected by flow cytometry. Finally, protein expression in the Wnt pathway activated by p53 was detected by Western blotting. Results: Compared with the sham group, p53 levels, mNSS, cerebral infarction area, and apoptosis were significantly increased in the MCAo group (p < 0.05). When the p53 inhibitor PFT-α was injected, the increase in these levels was reversed. Also, the viability and migration of cells decreased and apo­ptosis increased in the in vitro OGD model, whereas the viability, migration, and apoptosis were significantly reversed after the addition of p53 inhibitors (p < 0.05). Finally, p53 induced Wnt signaling pathway proteins β-catenin and cyclin D1 decrease in the MCAo group, while p53 inhibitors reversed their inhibitory effect on the Wnt signaling pathway. Conclusion: We confirmed in vivo and in vitro that inhibition of p53 has a protective effect on the cerebral ischemia-reperfusion injury, which may be related to the activation of the Wnt signaling pathway.

MiR-103-3p targets Ndel1 to regulate neural stem cell proliferation and differentiation.

The regulation of adult neural stem cells (NSCs) is critical for lifelong neurogenesis. MicroRNAs (miRNAs) are a type of small, endogenous RNAs that regulate gene expression post-transcriptionally and influence signaling networks responsible for several cellular processes. In this study, miR-103-3p was transfected into neural stem cells derived from embryonic hippocampal neural stem cells. The results showed that miR-103-3p suppressed neural stem cell proliferation and differentiation, and promoted apoptosis. In addition, miR-103-3p negatively regulated NudE neurodevelopment protein 1-like 1 (Ndel1) expression by binding to the 3' untranslated region of Ndel1. Transduction of neural stem cells with a lentiviral vector overexpressing Ndel1 significantly increased cell proliferation and differentiation, decreased neural stem cell apoptosis, and decreased protein expression levels of Wnt3a, β-catenin, phosphor-GSK-3β, LEF1, c-myc, c-Jun, and cyclin D1, all members of the Wnt/β-catenin signaling pathway. These findings suggest that Ndel1 is a novel miR-103-3p target and that miR-103-3p acts by suppressing neural stem cell proliferation and promoting apoptosis and differentiation. This study was approved by the Animal Ethics Committee of Nantong University, China (approval No. 20200826-003) on August 26, 2020.

The Role of Pink1-Mediated Mitochondrial Pathway in Propofol-Induced Developmental Neurotoxicity.

The mechanisms underlying propofol-induced toxicity in developing neurons are still unclear. The aim of present study was to explore the role of Pink1 mediated mitochondria pathway in propofol-induced developmental neurotoxicity. The primary Neural Stem Cells (NSCs) were isolated from the hippocampus of E15.5 mice embryos and then treated with propofol. The effects of propofol on proliferation, differentiation, apoptosis, mitochondria ultrastructure and MMP of NSCs were investigated. In addition, the abundance of Pink1 and a group of mitochondria related proteins in the cytoplasm and/or mitochondria were investigated, which mainly included CDK1, Drp1, Parkin1, DJ-1, Mfn1, Mfn2 and OPA1. Moreover, the relationship between Pink1 and these molecules was explored using gene silencing, or pretreatment with protein inhibitors. Finally, the NSCs were pretreated with mitochondrial specific antioxidant (MitoQ) or Drp1 inhibitor (Mdivi-1), and then the toxic effects of propofol on NSCs were investigated. Our results indicated that propofol treatment inhibited NSCs proliferation and division, and promoted NSCs apoptosis. Propofol induced significant NSCs mitochondria deformation, vacuolization and swelling, and decreased MMP. Additional studies showed that propofol affected a group of mitochondria related proteins via Pink1 inhibition, and CDK1, Drp1, Parkin1 and DJ-1 are the important downstream proteins of Pink1. Finally, the effects of propofol on proliferation, differentiation, apoptosis, mitochondrial ultrastructure and MMP of NSCs were significantly attenuated by MitoQ or Mdivi-1 pretreatment. The present study demonstrated that propofol regulates the proliferation, differentiation and apoptosis of NSCs via Pink1mediated mitochondria pathway.