RESUMO
MXenes have attracted extensive attention due to their unique physicochemical properties. Especially, the flexibility and good conductivity endow MXenes with a great application prospect in the neural interfaces. However, the cytotoxicity of MXenes to nervous system remains unclear. In this study, we evaluated the cytotoxicity of Ti3C2 (the most studied MXenes) using primary neural stem cells (NSCs) and NSCs-derived differentiated cells in terms of apoptosis, viability, cellular uptake, cell membrane integrity, and global gene expression profiles. We found that 12.5 µg/mL Ti3C2 had no observable adverse effect on NSCs and NSCs-derived differentiated cells. However, 25 µg/mL Ti3C2 induced significant cytotoxicity and were internalized into the NSCs cells with compromised cell membrane. Furthermore, in the NSCs exposure to 25 µg/mL Ti3C2, we identified 198 differently expressed genes (DEGs), which were mainly associated with the extracellular region. Besides, the DEGs were involved in inflammatory, defense, stress, and stimulus response. This work will improve our understanding of biocompatibility of MXenes in the nervous system and promote the biomedical application of MXenes.
Assuntos
Células-Tronco Neurais/efeitos dos fármacos , Titânio/farmacologia , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Camundongos , Tamanho da Partícula , Titânio/químicaRESUMO
After ischemia and reperfusion (I/R), nerve cell damage is a pathogenic process that involves numerous molecular processes. In the last ten years, one new classification of programmed cell death is ferroptosis. More recent research has demonstrated that ferroptosis has a role in a variety of neurological disorders, including stroke, cancer, and neurodegenerative illnesses. Ferroptosis suppressor protein 1 (FSP1) plays a significant role in inhibiting ferroptosis. The purpose of this work is to determine how overexpression of FSP1 affects the ferroptosis of PC12 cells under the condition of oxygen-glucose deprivation/reoxygenation (OGD/R). The expression of FSP1 was regulated by lentivirus transfection technology. Western blot and immunofluorescence were used to measure protein levels related to ferroptosis and the PI3K/AKT/GSK3ß signal pathway. Determine cell viability using the appropriate kit. Mitochondrial structural morphology was checked by transmission electron microscopy in PC12 cells. Reactive oxygen species (ROS) and Malondialdehyde (MDA) were quantified using the relevant kits. OGD/R induced ferroptosis in PC12 cells, however, FSP1 overexpression reverses ferroptosis and promotes cell viability, lowering ROS and MDA content. The expression of FSP1 decreased in OGD/R0h and OGD/R6h and rebounded in OGD/R24h and OGD/R48h. During the processes of OGD/R-induced ferroptosis, FSP1 overexpression significantly stimulated PI3K/AKT/GSK3ß pathway, but LY294002 weakens the protective effect of FSP1 overexpression. Our outcomes demonstrate that overexpression of FSP1 markedly enhances the ability to resist ferroptosis via the PI3K/AKT/GSK3ß pathway. The above results may provide a new preliminary lead for the treatment of the cerebral ischemia-reperfusion injury.
RESUMO
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 αvß3/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.
RESUMO
BACKGROUND AND AIM: Functional recovery is associated with the preservation of dendritic spines in the penumbra area after stroke. Previous studies found that polymerized microtubules (MTs) serve a crucial role in regulating dendritic spine formation and plasticity. However, the mechanisms that are involved are poorly understood. This study is designed to understand whether the upregulation of acetylated α-tubulin (α-Ac-Tub, a marker for stable, and polymerized MTs) could alleviate injury to the dendritic spines in the penumbra area and motor dysfunction after ischemic stroke. METHODS: Ischemic stroke was mimicked both in an in vivo and in vitro setup using middle cerebral artery occlusion and oxygen-glucose deprivation models. Thy1-YFP mice were utilized to observe the morphology of the dendritic spines in the penumbra area. MEC17 is the specific acetyltransferase of α-tubulin. Thy1 CreERT2-eYFP and MEC17fl/fl mice were mated to produce mice with decreased expression of α-Ac-Tub in dendritic spines of pyramidal neurons in the cerebral cortex. Moreover, AAV-PHP.B-DIO-MEC17 virus and tubastatin A (TBA) were injected into Thy1 CreERT2-eYFP and Thy1-YFP mice to increase α-Ac-Tub expression. Single-pellet retrieval, irregular ladder walking, rotarod, and cylinder tests were performed to test the motor function after the ischemic stroke. RESULTS: α-Ac-Tub was colocalized with postsynaptic density 95. Although knockout of MEC17 in the pyramidal neurons did not affect the density of the dendritic spines, it significantly aggravated the injury to them in the penumbra area and motor dysfunction after stroke. However, MEC17 upregulation in the pyramidal neurons and TBA treatment could maintain mature dendritic spine density and alleviate motor dysfunction after stroke. CONCLUSION: Our study demonstrated that α-Ac-Tub plays a crucial role in the maintenance of the structure and functions of mature dendritic spines. Moreover, α-Ac-Tub protected the dendritic spines in the penumbra area and alleviated motor dysfunction after stroke.
Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Camundongos , Animais , Espinhas Dendríticas/metabolismo , Tubulina (Proteína)/metabolismo , AVC Isquêmico/metabolismo , Células Piramidais/fisiologia , Acidente Vascular Cerebral/metabolismoRESUMO
Hemostatic sealant is required to deal with blood loss, especially in the scenario of traumatic brain injury (TBI), which presents high rates of morbidity and disability. Hemostasis in surgery with traditional gelatin-based sealants often leads to blood loss and other issues in brain because of the hydrophilic gelatin swelling. Herein, hydrophobic effects on the hemostasis in TBI surgery are studied by tuning the chain length of polystyrene (PS) onto methylacrylated gelatin (Gel-MA). The hydrophobicity and hemostatic efficiency can be tuned by controlling the length of PS groups. The platelet activation of modified sealants Gel-MA-2P, Gel-MA-P, and Gel-MA-0.5P is as much as 17.5, 9.1, and 2.1 times higher than Gel-MA in vitro. The hemostatic time of Gel-MA-2P, Gel-MA-P, and Gel-MA-0.5P groups is 2.0-, 1.6-, and 1.1-folds faster than that in Gel-MA group in TBI mice. Increased formation of fibrins and platelet aggregation can also be observed in vitro by scanning electron microscopy. Animal's mortality is lowered by 46%, neurologic deficiency is reduced by 1.5 times, and brain edema is attenuated by 10%. Protein expression is further investigated to exhibit toxic iron-related processes caused by delayed hemostasis and activation of platelets via PI3K/PKC-α signaling. The hydrophobic Gel-MA has the potential in hemostatic TBI and promotes nervous system recovery in brain with the potentials in clinics.
Assuntos
Lesões Encefálicas Traumáticas , Hemostáticos , Camundongos , Animais , Gelatina/farmacologia , Poliestirenos , Hemostasia , Hemostáticos/farmacologia , Hemorragia , Lesões Encefálicas Traumáticas/terapiaRESUMO
The mitochondrial permeability transition pore is a nonspecific transmembrane channel. Inhibition of mitochondrial permeability transition pore opening has been shown to alleviate mitochondrial swelling, calcium overload, and axonal degeneration. Cyclophilin D is an important component of the mitochondrial permeability transition pore. Whether cyclophilin D participates in mitochondrial impairment and axonal injury after intracerebral hemorrhage is not clear. In this study, we established mouse models of intracerebral hemorrhage in vivo by injection of autologous blood and oxyhemoglobin into the striatum in Thy1-YFP mice, in which pyramidal neurons and axons express yellow fluorescent protein. We also simulated intracerebral hemorrhage in vitro in PC12 cells using oxyhemoglobin. We found that axonal degeneration in the early stage of intracerebral hemorrhage depended on mitochondrial swelling induced by cyclophilin D activation and mitochondrial permeability transition pore opening. We further investigated the mechanism underlying the role of cyclophilin D in mouse models and PC12 cell models of intracerebral hemorrhage. We found that both cyclosporin A inhibition and short hairpin RNA interference of cyclophilin D reduced mitochondrial permeability transition pore opening and mitochondrial injury. In addition, inhibition of cyclophilin D and mitochondrial permeability transition pore opening protected corticospinal tract integrity and alleviated motor dysfunction caused by intracerebral hemorrhage. Our findings suggest that cyclophilin D is used as a key mediator of axonal degeneration after intracerebral hemorrhage; inhibition of cyclophilin D expression can protect mitochondrial structure and function and further alleviate corticospinal tract injury and motor dysfunction after intracerebral hemorrhage. Our findings provide a therapeutic target for preventing axonal degeneration of white matter injury and subsequent functional impairment in central nervous diseases.
RESUMO
This systematic review evaluated the dietary experience of patients with obesity post-bariatric surgery. Scopus, CINAHL, Medline, Psych INFO, and Embase databases were searched and JBI Critical Appraisal Tool was used for quality assessment. Thomas and Harden's three-stage thematic synthesis was undertaken using the Enhancing transparency in reporting the synthesis of qualitative research (ENTREQ) statement for reporting. Of the 24 studies extracted, we coded and developed 34 descriptive themes into 7 categories, which were then categorized to 3 analytical themes. The number of all the participants in the 24 articles is 383 people. The results revealed most patients can control their diet for a short period post-surgery. However, this was a matter of gradual self-consciousness as patients also required support and dietary management in postoperative recovery. CLINICAL TRIAL REGISTRATION NUMBER: The protocol for this qualitative systematic review has been registered with PROSPERO (registration number CRD42021229083).
Assuntos
Cirurgia Bariátrica , Obesidade Mórbida , Dieta , Humanos , Obesidade Mórbida/cirurgia , Pesquisa QualitativaRESUMO
The encapsulation of cells with various polyelectrolytes through layer-by-layer (LbL) has become a popular strategy in cellular function engineering. The technique sprang up in 1990s and obtained tremendous advances in multi-functionalized encapsulation of cells in recent years. This review comprehensively summarized the basis and applications in drug delivery by means of LbL cell encapsulation. To begin with, the concept and brief history of LbL and LbL cell encapsulation were introduced. Next, diverse types of materials, including naturally extracted and chemically synthesized, were exhibited, followed by a complicated basis of LbL assembly, such as interactions within multilayers, charge distribution, and films morphology. Furthermore, the review focused on the protective effects against adverse factors, and bioactive payloads incorporation could be realized via LbL cell encapsulation. Additionally, the payload delivery from cell encapsulation system could be adjusted by environment, redox, biological processes, and functional linkers to release payloads in controlled manners. In short, drug delivery via LbL cell encapsulation, which takes advantage of both cell grafts and drug activities, will be of great importance in basic research of cell science and biotherapy for various diseases.
RESUMO
Promoting neurogenesis and proliferation of endogenous neural stem/progenitor cells (NSPCs) is considered a promising strategy for neurorehabilitation after stroke. Our previous study revealed that a moderate dose of artesunate (ART, 150 mg/kg) could enhance functional recovery in middle cerebral artery occlusion (MCAO) mice. This study aimed to investigate the effects of ART treatment on neurogenesis and proliferation of NSPCs using a rodent MCAO model. MRI results indicated that the ischemic brain volume of MCAO mice was reduced by ART treatment. The results of diffusion tensor imaging, electron microscopic, and immunofluorescence of Tuj-1 also revealed that ischemia-induced white matter lesion was alleviated by ART treatment. After ischemia/reperfusion, the proportion of Brdu + endogenous NSPCs in the ipsilateral subventricular zone and peri-infarct cortex was increased by ART treatment. Furthermore, the neuro-restorative effects of ART were abolished by the overexpression of FOXO3a. These findings suggested that ART could rescue ischemia/reperfusion damage and alleviate white matter injury, subsequently contributing to post-stroke functional recovery by promoting neurogenesis and proliferation of endogenous NSPCs via the FOXO3a/p27Kip1 pathway.
Assuntos
Isquemia Encefálica , Células-Tronco Neurais , Acidente Vascular Cerebral , Animais , Artesunato/metabolismo , Artesunato/farmacologia , Artesunato/uso terapêutico , Isquemia Encefálica/patologia , Proliferação de Células , Imagem de Tensor de Difusão , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/patologia , Camundongos , Células-Tronco Neurais/metabolismo , Neurogênese , Acidente Vascular Cerebral/patologiaRESUMO
Stem cell therapy, which has become a potential regenerative medical treatment and a promising approach for treating brain injuries induced by different types of cerebrovascular disease, has various application methods. Activation of endogenous neural stem cells (NSCs) can enable infarcted neuron replacement and promote neural networks' regeneration without the technical and ethical issues associated with the transplantation of exogenous stem cells. Thus, NSC activation can be a feasible strategy to treat central nervous system (CNS) injury. The potential molecular mechanisms of drug therapy for the activation of endogenous NSCs have gradually been revealed by researchers. Traditional Chinese medicine monomers (TCMs) are active components extracted from Chinese herbs, and some of them have demonstrated the potential to activate proliferation and neurogenesis of NSCs in CNS diseases. Ginsenoside Rg1, astragaloside IV (AST), icariin (ICA), salvianolic acid B (Sal B), resveratrol (RES), curcumin, artesunate (ART), and ginkgolide B (GB) have positive effects on NSCs via different signaling pathways and molecules, such as the Wingless/integrated/ß-catenin (Wnt/ß-catenin) signaling pathway, the sonic hedgehog (Shh) signaling pathway, brain-derived neurotrophic factor (BDNF), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1). This article may provide further motivation for researchers to take advantage of TCMs in studies on CNS injury and stem cell therapy.
RESUMO
Long non-coding RNAs (lncRNAs) serve essential roles on various biological functions. Previous studies have indicated that lncRNAs are involved in the occurrence, growth and infiltration of brain tumors. LncRNA H19 is key regulator in the pathogenesis of gliomas, but the underlying mechanisms of H19-regulated tumor progression remain unknown. Therefore, we investigated the effects and mechanism of action of lncRNA H19 on the homeostasis of glioma cells. As a novel oncogenic factor, up-regulation of H19 was able to promote the proliferation of glioma cells by targeting miR-200a. Furthermore, elevated miR-200a levels could reverse H19-induced cell growth and metastasis. Overexpression of miR-200a could significantly suppress the proliferation, migration and invasion of glioma cells. These biological behavior changes in glioma cells were dependent on the binding to potential target genes including CDK6 and ZEB1. CDK6 could promote cell proliferation and its expression was remarkably increased in glioma. In addition, up-regulation of miR-200a lead to reduction of CDK6 expression and inhibit the proliferation of glioma cells. ZEB1 could be a putative target gene of miR-200a in glioma cells. Thus, miR-200a might suppress cell invasion and migration through down-regulating ZEB1. Moreover, overexpression of miR-200a resulted in down-regulation of ZEB1 and further inhibited malignant phenotype of glioma cells. In summary, our findings suggested that the expression of H19 was elevated in glioma, which could promote the growth, invasion and migration of tumor cells via H19/miR-200a/CDK6/ZEB1 axis. This novel signaling pathway may be a promising candidate for the diagnosis and targeted treatment of glioma.
RESUMO
Enhancing the therapeutic efficacy of anti-tumor drugs is essential for cancer management. Although cannabinoid receptor 2 (CB2R) stimulation exerts anti-tumor action in glioma cells by regulating cellular proliferation, differentiation, or apoptosis, selective CB2R agonist alone does not achieve a satisfactory therapeutic outcome. Herein, we aimed to evaluate the possible strategy for enhancing the anti-glioma efficacy of JWH133, a selective CB2R agonist. In this study, immunofluorescence and qRT-PCR were used to investigate microglia polarization. Tumor growth was monitored via bioluminescent imaging using the IVIS Spectrum System. The angiogenesis of human brain microvascular endothelial cells (HBMECs) was detected by the tube formation assay. qRT-PCR was used to investigate cytochrome P450 2J2 (CYP2J2) and 11,12-epoxyeicosatrienoic acid (11,12-EET) expression. Our results showed that administration of JWH133 significantly promoted microglial M2 polarization both in vitro and in vivo. The medium supernatant of M2 microglia induced by JWH133 treatment facilitated angiogenesis of HBMECs. CYP2J2 expression and 11,12-EET release in the supernatant of JWH133-induced M2 microglia were significantly upregulated. Treatment with 11,12-EET prompted HBMEC angiogenesis and glioma growth. CYP2J2 knockdown restrained the release of 11,12-EET and significantly enhanced the anti-tumor effect of JWH133 on glioma. This study showed that targeting CYP2J2 might be a beneficial strategy to enhance the anti-glioma efficacy of JWH133 by inhibiting the pro-angiogenesis function of M2 microglia.
RESUMO
Bombyx mori is a lepidopteran insect with important economic value. Bombyx mori nucleopolyhedrovirus (BmNPV) causes huge economic loss to silkworm industry in China every year. The objective of this study is to determine the anti-BmNPV mechanism of Bombyx mori strain NC99R, and to provide a basis for understanding the molecular mechanism of the silkworm resistance strain. The normal control Dazao (DZ) strain and the NC99R resistant strain were fed with occlusion bodies (OB). The median lethal dose (LD50) analysis of the DZ and NC99R showed that the LD50 of DZ was 1.2×105 OBs/larva, while NC99R was 1.8×106 OBs/larva. The LD50 of the NC99R was about 15 times higher than the DZ. The mortality of DZ and NC99R were analyzed, which were fed with 1×106 OBs/larva and injection with 1×106 BVs/larva. The results showed that the death peak of DZ was concentrated in the 4th to 6th day. And the death peak of NC99R was concentrated in the 6th to 8th day, with a delay of 1-2 days compared with the control. The BmNPV DNA copy number showed that the BmNPV genome in DZ proliferated rapidly. The copy number of BmNPV DNA in NC99R were increased slowly after oral infection and body injection. HE staining showed that midgut tissue has no significant difference between DZ and NC99R in the early stage of oral infection. At 96 h p.i., the nucleus of DZ midgut became larger and shedding. The NC99R had enlarged nuclei, but the cells were still arranged neatly. Finally, the expression of virus genes in different periods were analyzed by RT-PCR. The results indicated that the immediate early gene ie-1 expression levels began to down-regulate after 24 h p.i.. The early, late, and extremely late genes were also down-regulated, and finally maintained at a lower expression level.
Assuntos
Bombyx , Nucleopoliedrovírus , Animais , China , LarvaRESUMO
Stroke is one of the leading causes of death worldwide that also result in long-term disability. Endogenous neural stem/progenitor cells (NSPCs) within subventricular (SVZ) and dentate gyrus (DG) zone, stimulated by cerebral infarction, can promote neural function recovery. However, the proliferation of eNSPCs triggered by ischemia is not enough to induce neural repair, which may contribute to the permanent disability in stroke patients. In this study, our results showed that following the treatment with artesunate (ART, 150 mg/kg), the functional recovery was significantly improved, the infarct volume was notably reduced, and the expression of Nestin, a proliferation marker of NSPCs in the infarcted cortex, was also increased. Additionally, the proliferative activity of NSPCs with or without oxygen-glucose deprivation/reperfusion was significantly promoted by ART treatment, and the therapeutic concentration was 0.8 µmol/L (without OGD/R) or 0.4 µmol/L (with OGD/R) in the in vitro model. Furthermore, the effects of ART can be abolished by the treatment of PI3K inhibitor wortmannin. The expression levels of related molecules in PI3K/Akt/FOXO-3a/p27kip1 signaling pathway (p-AKT, p-FOXO-3a, p27kip1) were examined using western blotting. The results suggested ART could inhibit the transcriptional function of FOXO-3a by inducing its phosphorylation, subsequently downregulating p27kip1 and enhancing neural stem cell proliferation in the infarcted cortex via PI3K/AKT signaling, further alleviating ischemia-reperfusion injury after ischemic stroke.
Assuntos
Artesunato/farmacologia , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Células-Tronco Neurais/patologia , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Regulação para Baixo , Fatores de Transcrição Forkhead/metabolismo , Células-Tronco Neurais/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Transdução de SinaisRESUMO
Iron-mediated toxicity is a key factor causing brain injury after intracerebral hemorrhage (ICH). This study was performed to investigate the noninvasive neuroimaging method for quantifying brain iron content using a minipig ICH model and assess the effects of minocycline treatment on ICH-induced iron overload and brain injury. The minipig ICH model was established by injecting 2 ml of autologous blood into the right basal ganglia, which were then subjected to the treatments of minocycline and vehicle. Furthermore, the quantitative susceptibility mapping (QSM) was used to quantify iron content, and diffusion tensor imaging (DTI) was performed to evaluate white matter tract. Additionally, we also performed immunohistochemistry, Western blot, iron assay, Perl's staining, brain water content, and neurological score to evaluate the iron overload and brain injury. Interestingly, we found that the ICH-induced iron overload could be accurately quantified by the QSM. Moreover, the minocycline was quite beneficial for protecting brain injury by reducing the lesion volume and brain edema, preventing brain iron accumulation, downsizing ventricle enlargement, and alleviating white matter injury and neurological deficits. In summary, we suggest that the QSM be an accurate and noninvasive method for quantifying brain iron level, and the minocycline may be a promising therapeutic agent for patients with ICH.
Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/patologia , Quelantes/administração & dosagem , Ferro/toxicidade , Imageamento por Ressonância Magnética , Minociclina/administração & dosagem , Animais , Encéfalo/metabolismo , Hemorragia Cerebral/metabolismo , Masculino , Suínos , Porco MiniaturaRESUMO
Plasmopara viticola, the causal oomycete of grapevine downy mildew disease, secrets a series of RXLR effectors to manipulate host immunity. In this study, we characterized the role of a RXLR effector of P. viticola, PvRXLR159, in plant-microbe interaction. Transcription of PvRXLR159 in P. viticola was induced in the early stage of infection in grapevine (Vitis vinifera 'Thomson Seedless'). Further results revealed that PvRXLR159 contains a functional signal peptide and its C terminus was essential to inhibit cell death by elicitors, INF1 and BAX, in Nicotiana benthamiana. Transient expression of PvRXLR159 suppressed N. benthamiana resistance to a pathogenic oomycete, Phytophthora capsici. Taken together, we propose that PvRXLR159 is induced and secreted by P. viticola to suppress host resistance.
Assuntos
Nicotiana/imunologia , Oomicetos/fisiologia , Proteínas/metabolismo , Resistência à Doença , Regulação da Expressão Gênica de Plantas , Phytophthora/fisiologia , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Sinais Direcionadores de Proteínas , Proteínas/química , Nicotiana/genética , Nicotiana/microbiologia , Transcrição GênicaRESUMO
Ischemic stroke is one of the most leading diseases causing death/long-term disability worldwide. Activating endogenous neural stem/progenitors cells (NSPCs), lining in the subventricular zone (SVZ) and dentate gyrus, facilitates injured brain tissue recovery in both short and long-term experimental settings. While, only a few proliferated NSPCs migrate toward the lesions to enhance endogenous repair after ischemia. Here, the results indicated that the functional recovery was evidently improved and the infarct volume was significantly reduced with ascorbic acid (AA) treatment in a dose-dependent manner from 125 to 500 mg/Kg, and the suitable therapeutic concentration was 250 mg/Kg. The possible mechanism might be due to activating sodium-vitamin C cotransporter 2 (SVCT2), which was down-regulated in SVZ after ischemia. Furthermore, immunostaining images depicted the number of migrated NSPCs from SVZ were significantly increased with 250 mg/Kg AA treatment or SVCT2 overexpression under the physiological and pathological condition in vivo. Besides, the data also represented that 250 mg/Kg AA or SVCT2 overexpression facilitated NSPCs migration via promoting F-actin assembling in the manner of up-regulating CDC42 expression using oxygen-glucose deprivation in vitro. Collectively, the present study indicates that SVCT2 promotes NSPCs migration through CDC42 activation to facilitate F-actin assembling, which enlarges the therapeutic scope of AA and the role of SVCT2 in NSPCs migration after brain injury.
RESUMO
Mesolimbic dopamine (DA) system lesion plays a key role in the pathophysiology of depression, and our previous study demonstrated that reduced microtubule (MT) stability aggravated nigrostriatal pathway impairment after intracerebral hemorrhage (ICH). This study aimed to further investigate the occurrence regularity of depression-like behavior after ICH and determine whether maintaining MT stabilization could protect DA neurons in ventral tegmental area (VTA) and alleviate depression-like behavior after ICH. An intrastriatal injection of 20 µl of autologous blood or MT depolymerization reagent nocodazole (Noco) was used to mimic the pathology of ICH model in mice. The concentration of DA, number of DA neurons and acetylated α-tubulin (a marker for stable MT) in VTA were checked, and depression-related behavior tests were performed after ICH. A MT-stabilizing agent, epothilone B (EpoB), was administered to explore the effects of MT stabilization on DA neurons and depression-like behavior after ICH. The results showed that obvious depression-like behavior occurred at 7, 14, and 28 days (P < 0.01) after ICH. These time-points were related to significant decreases in the concentration of DA (P < 0.01) and number of DA neurons (P < 0.01) in VTA. Moreover, The decrease of acetylated α-tubulin expression after ICH and Noco injection contributed to DA neurons' impairment in VTA, and Noco injecton also aggravate ICH-induced depression-like behaviors and DA neurons' injury. Furthermore, EpoB treatment significantly ameliorated ICH and Noco-induced depression-like behaviors (P < 0.05) and increased the concentration of DA (P < 0.05) and number of DA neurons (P < 0.05) in VTA by increasing the level of acetylated α-tubulin. The results indicate that EpoB can protect DA neurons by enhancing MT stability, and alleviate post-ICH depressive behaviors. This MT-targeted therapeutic strategy shows promise as a bench-to-bedside translational method for treating depression after ICH.
Assuntos
Depressão/metabolismo , Neurônios Dopaminérgicos/metabolismo , Epotilonas/uso terapêutico , Microtúbulos/metabolismo , Animais , Hemorragia Cerebral/complicações , Hemorragia Cerebral/tratamento farmacológico , Depressão/tratamento farmacológico , Neurônios Dopaminérgicos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microtúbulos/efeitos dos fármacos , Área Tegmentar Ventral/efeitos dos fármacos , Área Tegmentar Ventral/metabolismoRESUMO
Pathogen-inducible promoters have been studied extensively and widely used in resistance breeding and gene therapy. However, few reports have been published that explore the efficacy of Bombyx mori nucleopolyhedrovirus (BmNPV)-inducible promoters in antiviral research in the Bombyx mori (Lepidoptera). Here, we screened BmNPV promoters (VP1054, P33, Bm21, Bm122, 39K, P143, and P6.9) and found that the 39K promoter had the highest BmNPV-induced transcriptional activity by dual-luciferase reporter assays system. By 5' truncation analysis, two regions of 39K promoter were critical for optimal virus-inducible activity, indicated that they could serve as a candidate to produce synthetic pathogen-induced promoters. Furthermore, we enhanced the virus-inducible activity of BmNPV 39K promoter using a hybrid enhancer comprising hr3 and polh-up (designated as HP39K). Finally, we showed that RNAi regulated by HP39K promoter could significantly inhibit the proliferation of BmNPV in silkworm cells. Taken together, our results have practical value in antiviral research of silkworm and baculovirus expression system.