RESUMO
Learning and memory impairment is commonly noted in Alzheimer's disease (AD), which is regarded as a progressive synaptic failure disease. Exercise is a nonpharmacological strategy that may help prevent cognitive decline and reduce the risk of AD, which is usually thought to be related to synaptic damage in the hippocampus. However, the effects of exercise intensity on hippocampal memory and synaptic function in AD remain unclear. In this study, senescence-accelerated mouse prone-8 (SAMP8) mice were randomly assigned to the control group (Con), low-intensity exercise group (Low), and moderate-intensity exercise group (Mid). Here, we showed that eight weeks of treadmill exercise beginning in four-month-old mice improved spatial memory and recognition memory in six-month-old SAMP8 mice, while the Con group exhibited impaired spatial memory and recognition memory. Treadmill exercise also improved hippocampal neuron morphology in SAMP8 mice. Furthermore, dendritic spine density and the levels of postsynaptic density protein-95 (PSD95) and Synaptophysin (SYN) increased significantly in the Low and Mid groups as compared with the Con group. We further showed that moderate-intensity exercise (60 % of maximum speed) was more efficacious in increasing dendritic spine densityãPSD95 and SYN, than low-intensity exercise (40 % of maximum speed). In conclusion, the positive effect of treadmill exercise is closely related to exercise intensity, with moderate-intensity exercise showing the most optimal effects.
Assuntos
Doença de Alzheimer , Memória Espacial , Camundongos , Animais , Envelhecimento/psicologia , Hipocampo , Transtornos da Memória , Proteína 4 Homóloga a Disks-Large , Modelos Animais de DoençasRESUMO
BACKGROUND: Medical education accreditation in China has been conducted by the Working Committee for the Accreditation of Medical Education (WCAME) and 129 medical schools have completed accreditation by December 2021. Despite studies on the standards, process and effectiveness of accreditation, the actual information transparency of accredited medical schools in China has not been examined. The study investigated the status of publicly available information from WCAME-accredited medical schools in China, and whether public availability of information had significant differences among different types of universities. METHODS: The 129 medical schools' official websites were reviewed for the 21 criteria of the WFME Global Standards for Quality Improvement: Basic Medical Education. Dichotomous method was used to record information as presence or absence. SPSS was utilized for descriptive and ANOVA analyses. RESULTS: The mean of the publicly available information on the 21 criteria was 13.77 ± 3.57, and only 5 (3.9%) accredited medical schools had all relevant information available. Publicly available information on Governance (100%) and Administration (100%) was the most, whereas information on Assessment in support of learning (16.3%) was the least. Public availability of information differed significantly among schools accredited with higher (18.15 ± 2.16), medium (13.69 ± 3.41) and lower results (12.79 ± 3.19) (F = 14.71, p < 0.05). Medical universities and comprehensive universities did not show significant differences in their overall information availability (F = 0.25, p > 0.05). Central government funded universities had a remarkably larger amount of publicly available information than local government funded universities (17.86 ± 1.98 vs. 12.75 ± 2.93, p < 0.05). CONCLUSION: Public availability of information from the accredited medical schools in China needs to be improved to promote transparency and continuous quality improvement, especially with regard to information on curriculum, assessment and quality assurance. Explicit information availability requirements need to be considered to include in medical education standards, and further studies are warranted to explore which information elements should be made publicly available.
Assuntos
Educação Médica , Faculdades de Medicina , Acreditação , China , Currículo , Educação Médica/métodos , HumanosRESUMO
The neural crest is a multipotent cell population that migrates extensively to play important roles during embryonic development. After acquiring motility, trunk neural crest cells delaminate from the spinal cord and migrate to various regions of the body. Several cellular adhesion molecules, such as vinculin, are involved in the regulation of neural crest delamination and migration. In the present study, we found that draxin could inhibit delamination and migration of neural crest cells from the chick spinal cord and abnormal aggregation of the migrating neural crest cells. In the presence of draxin, the resuspended neural crest regained its adhesive ability such that it was significantly increased. Overexpression of draxin caused increased vinculin expression in vivo. Our data indicate that draxin might control delamination and migration of chick trunk neural crest by increasing cell adhesion.
Assuntos
Galinhas , Crista Neural , Animais , Adesão Celular , Movimento Celular , Medula EspinalRESUMO
This study aims to test the role of E2F1-topoIIß signaling in neuronal differentiation of SH-SY5Y cells. With retinoic acid (RA) induction, a high percentage of cells were found to be arrested at the G0/G1 phase, with decreased levels of cyclinD1, CDK4, phosphorylation status of pRb and E2F1, in addition to an elevated level of p27. The cells were shown to differentiate into neuronal phenotypes characterized by highly expressed neuronal markers, MAP2 and enriched topoIIß, and remarkable neurite outgrowth. Exogenously forced E2F1 expression with a specific E2F1 plasmid led to suppression of topoIIß expression and disruption of the neuronal differentiation of SH-SY5Y cells. On further examination using the ChIP assay, we found that E2F1 bound directly to the promoter region of topoIIß, and its binding ability was inversely correlated with topoIIß expression in response to RA induction. Thus, our findings suggest that E2F1-topoIIß signaling may play a role in regulation of cell cycle exit and neuronal differentiation.
Assuntos
Diferenciação Celular/genética , DNA Topoisomerases Tipo II/genética , Fator de Transcrição E2F1/genética , Neurônios/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/genética , Ciclo Celular/genética , Linhagem Celular , Ciclina D1/genética , Quinase 4 Dependente de Ciclina/genética , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Proteínas Associadas aos Microtúbulos/genética , Regiões Promotoras Genéticas , Ligação Proteica/genética , Proteína do Retinoblastoma/genética , Transdução de Sinais/genética , Tretinoína/farmacologiaRESUMO
BACKGROUND/AIMS: Sulforaphane-N-acetyl-cysteine (SFN-NAC) is a sulforaphane (SFN) metabolite with a longer half-life and better blood-brain barrier permeability than those of SFN. Previous studies have found that SFN-NAC can act via ERK to destroy microtubules and inhibit cell growth in lung cancer cells. However, the underlying mechanisms are unclear, and it is unknown whether SFN-NAC can inhibit the growth of glioma. Here, we have demonstrated for the first time that SFN-NAC activates autophagy-mediated downregulation of α-tubulin expression via the ERK pathway. METHODS: U87MG and U373MG cells, two widely used glioma cell lines, were utilized in this study. Apoptosis assay, western blot analysis, co-immunoprecipitation, immunostaining, and electron microscopy were used to analyze the effect of SFN-NAC on α-tubulin and its interaction with microtube-associated protein 1 light-chain 3 (LC3). RESULTS: SFN-NAC induced cell-cycle arrest in the G2/M phase and dose-dependently induced intracellular ERK activation, autophagy, and α-tubulin downregulation. These SFN-NAC-induced effects were reversed by inhibiting the ERK pathway with its inhibitor PD98059. U87MG and U373MG cells were transfected with LC3 small interfering RNA, and the subsequent inhibition of autophagy reversed the downregulation of α-tubulin by SFN-NAC. Furthermore, co-immunoprecipitation experiments and confocal microscopy confirmed that SFN-NAC promotes the binding of LC3 with α-tubulin in the cytoplasm. Cell viability experiments demonstrate that SFN-NAC inhibits the growth of U87MG and U373MG cell colonies. CONCLUSION: These findings suggest that SFN-NAC is a novel potential anti-glioma agent.
Assuntos
Acetilcisteína/análogos & derivados , Acetilcisteína/farmacologia , Anticarcinógenos/farmacologia , Autofagia/efeitos dos fármacos , Isotiocianatos/farmacologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Acetilcisteína/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Bases de Dados Factuais , Flavonoides/farmacologia , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Humanos , Isotiocianatos/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas Associadas aos Microtúbulos/antagonistas & inibidores , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Modelos de Riscos Proporcionais , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Sulfóxidos , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismoRESUMO
BACKGROUND/AIMS: The nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway plays a protective role in both acute neuronal damage and chronic neurodegeneration-related oxidative stress. Circular RNAs (circRNAs) are involved with various diseases in the central nervous system (CNS). This study aimed to identify the key circRNAs involved in Nrf2-neuroprotection against oxidative stress. METHODS: The differentially expressed circRNAs (DEcircRNAs) in the substantia nigra and corpus striatum between Nrf2 (-/-) and Nrf2 (+/+) mice were identified by microarray analysis. Quantitative real-time polymerase chain reaction (qRT-PCR) was then used to validate the expression of selected DEcircRNAs in the substantia nigra and corpus striatum between Nrf2 (-/-) and Nrf2 (+/+) mice. Based on our previous microarray analysis of the differentially expressed mRNAs (DEmRNAs) in the substantia nigra and corpus striatum between Nrf2 (-/-) and Nrf2 (+/+) mice, the DEcircRNA-miRNA-DEmRNA interaction network was constructed. Functional annotation of DEmRNAs that shared the same binding miRNAs with DEcircRNAs was performed using gene ontology (GO) and pathway analyses. RESULTS: A total of 65 and 150 significant DEcircRNAs were obtained in the substantia nigra and corpus striatum of Nrf2 (-/-) mice, respectively, and seventeen shared DEcircRNAs were found in both these two tissues. The qRT-PCR results were generally consistent with the microarray results. The DEcircRNA-miRNA-DEmRNA interaction network and pathway analysis indicated that mmu_circRNA_34132, mmu_circRNA_017077 and mmu-circRNA-015216 might be involved with Nrf2-mediated neuroprotection against oxidative stress. Mmu_circRNA_015216 and mmu_circRNA_017077 might play roles in the Nrf2-related transcriptional misregulation and Nrf2-mediated processes of rheumatoid arthritis, respectively. In addition to these two processes, mmu_circRNA_34132 may be a potential regulator of Nrf2-mediated protection for diabetes mellitus and Nrf2-mediated defence against ROS in hearts. CONCLUSION: In conclusion, our study identified the key DEcircRNAs in the substantia nigra and corpus striatum of Nrf2 (-/-) mice, which might provide new clues for further exploring the mechanism of Nrf2-mediated neuroprotection against oxidative stress and other Nrf2-mediated processes.
Assuntos
Corpo Estriado/metabolismo , Fator 2 Relacionado a NF-E2/genética , RNA/metabolismo , Substância Negra/metabolismo , Animais , Biologia Computacional , Redes Reguladoras de Genes/genética , Camundongos , Camundongos Knockout , MicroRNAs/metabolismo , Fator 2 Relacionado a NF-E2/deficiência , Análise de Sequência com Séries de Oligonucleotídeos , Estresse Oxidativo , RNA/genética , RNA Circular , RNA Mensageiro/metabolismoRESUMO
PURPOSE: This study aims to find a safe and easy-to-perform strategy for lumbar pedicle screw insertion based on anatomical landmarks. METHODS: From March 2011 to January 2012, 74 patients underwent posterior lumbar interbody fusion or transforaminal lumbar interbody fusion using the new-designed screw insertion technique. During the operation, the entry site for screw insertion was on the outer edge of the superior facet joint, 4 mm downward from upper border of processus transversus. A connecting line between superior and inferior facet joints was used to determine the direction of screw insertion. Postoperative radiograph and computed tomography (CT) were taken routinely to show the position of the screws. Functional outcomes were evaluated using Oswestry Disability Index score, Japanese Orthopedic Association score, and Visual Analogue Scale, respectively. RESULTS: Sixty-two patients (27 males and 35 females, average age 58.95 ± 8.45) finished the follow-up visit with an average of 46.03 months (36-60). The mean operation time and the blood loss were 169.60 ± 41.21 min and 489.52 ± 189.38 ml, respectively. A total of 274 pedicle screws were inserted following the new technique. According to Lothar Wiesner's classification, 11 screws (4.01%) caused minor violation into wall, two screws (0.73%) caused moderate violation, and other screws were in proper position. CONCLUSION: A new-designed surgical strategy for pedicle screw insertion of lumbar spine was introduced and performed, which featured a series of original and easily distinguished landmarks. Clinical application demonstrated the safety and effectiveness of this novel technique for pedicle screw insertion.
Assuntos
Vértebras Lombares/cirurgia , Parafusos Pediculares/efeitos adversos , Fusão Vertebral/métodos , Adulto , Idoso , Feminino , Seguimentos , Humanos , Deslocamento do Disco Intervertebral/cirurgia , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Fusão Vertebral/efeitos adversos , Estenose Espinal/cirurgia , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Escala Visual AnalógicaRESUMO
Nuclear factor erythroid 2 like 2 (Nrf2) functions as a neuroprotective agent in Parkinson's disease (PD). This study aimed to investigate the key long non-coding RNAs (lncRNAs) correlated with Nrf2, which might provide valuable information for the exploration of pathogenesis of PD. The lncRNA and mRNA expression profiling of substantia nigra and corpus striatum of Nrf2 (-/-) mice model was obtained from microarray analysis. The animal experiments conducted for this study were approved by the ethics committee of Hebei Medical University. Bioinformatics analyses were conducted, including differentially expressed lncRNAs/mRNA (differentially expressed lncRNA, DEL/differentially expressed mRNA, DEM) identification, DEL-DEM coexpression network construction, and biological functions prediction. Quantitative real-time polymerase chain reaction (qRT-PCR) was subjected to validate abnormally expressed DELs and DEMs in the substantia nigra and corpus striatum of Nrf2 (-/-) mice model. A total of 48 DELs (37 down-regulated and 11 up-regulated) were identified both in Nrf2 (-/-) substantia nigra and corpus striatum; 96 DEMs and 643 DEMs were identified in the substantia nigra and corpus striatum, respectively. DEL-DEM coexpressed network was constructed. LncRNA AK076880, AK036620, and AK020330 had high connectivity with DEMs both in the substantia nigra and corpus striatum. These DEMs were significantly enriched in signaling pathways such as the calcium signaling pathway, Huntington's disease, Alzheimer's disease, mitogen-activated protein kinase (MAPK) signaling pathway, and the Wnt signaling pathway. Generally, qRT-PCR validation results of selected DEMs and DELs were consistent with microarray data. The dysregulated DELs and DEMs in the substantia nigra and corpus striatum of Nrf2 (-/-) mice were identified. Our results might provide useful information for further exploring the pathogenesis mechanism of PD.
Assuntos
Corpo Estriado/metabolismo , Redes Reguladoras de Genes/fisiologia , Fator 2 Relacionado a NF-E2/deficiência , RNA Longo não Codificante/biossíntese , Substância Negra/metabolismo , Animais , Expressão Gênica , Masculino , Camundongos , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , RNA Longo não Codificante/genéticaRESUMO
PURPOSE: Laminectomy with lateral mass screw fixation has been proven to be an effective method to treat the multilevel cervical degenerative myelopathy and severe cervical spondylosis. However, accurate and safe insertion of the lateral mass screw is technically demanding due to the individual variations of the anatomy of the lateral mass of the subaxial cervical spine. Misplaced lateral mass screw is not uncommon, and operation-related complications still beset the surgeons, which may impair the clinical outcomes. This study aimed to introduce a novel strategy for safe and accurate insertion of lateral mass screw in the subaxial cervical spine. METHODS: From July 2014 to March 2015, 24 patients with multilevel cervical degenerative myelopathy at C3-C6 levels received laminectomy. Before the operation, the screw insertion technique depended on the pre-operative imaging and operative exploration. Following this strategy, the lateral mass screws were inserted into the subaxial cervical spines. Post-operative radiograph was performed to observe the locations of the lateral mass screws and the cervical curvature. Patients were followed up, and the functional neurological recovery was evaluated by the modified Japanese Orthopedic Association (JOA) disability scale, the Neck Disability Index (NDI) and NDI ranking system. RESULTS: All screws were inserted into the lateral mass of C3-C6 cervical vertebrae following the current technique. Post-operative CT scans confirmed all screws inserted into the safe zone and relative safe zone of the lateral mass without any screw placed into the transverse foramen. The angle between the lateral mass screw and the vertical line was 40.49 ± 5.44 degrees on the axial CT images. Twenty-four patients were followed up for an average of 25.79 months (range, 20-30 months), and 22 cases evaluated as no or mild disability. According to the JOA score, NDI score and NDI ranking system, the postoperative function of the patients was significantly better when compared with their preoperative corresponding data (all p < 0.001) CONCLUSION: Inserting lateral mass screw following this new strategy is safe and easy to perform without any screw-related neurovascular complications, which contribute to the rigid fixation of the subaxial cervical spine and the satisfactory functional recovery.
Assuntos
Parafusos Ósseos , Laminectomia/métodos , Doenças da Medula Espinal/cirurgia , Fusão Vertebral/métodos , Espondilose/cirurgia , Adulto , Idoso , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/cirurgia , Feminino , Seguimentos , Humanos , Laminectomia/instrumentação , Masculino , Pessoa de Meia-Idade , Doenças da Medula Espinal/diagnóstico por imagem , Fusão Vertebral/instrumentação , Espondilose/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
The potential influence of intranasal testosterone propionate (InTP) supplements on mesodopaminergic system in aged male rats was investigated by analyzing the exploratory and motor behaviors as well as dopamine neurobiochemical indices. Meanwhile, oxidative stress parameters and pathway of nuclear factor erythroid 2-related factor 2 (Nrf2)-binding antioxidant response elements (Nrf2-ARE) were examined to check whether the Nrf2-ARE pathway was involved in the InTP-induced alteration of mesodopaminergic system in aged male rats. The exploratory and motor behavioral deficits, as well as the reduced expression of dopamine, tyrosine hydroxylase, and dopamine transporter, which indicated the declined activity of mesodopaminergic system, were ameliorated in rats administered with 12-week InTP. The results indicated that chronic InTP supplements could effectively influence the brain function activity in a way opposite to the effect of aging on the mesodopaminergic system of rats. The increased levels of Nrf2, heme oxygenase-1, and NAD(P)H: quinone oxidoreductase-1 in the substantia nigra and ventral tegmental area, but not in the hippocampus of InTP-administered aged male rats, indicated that the ameliorative effect of InTP supplements on mesodopaminergic system might be related to the region-specific activation of the Nrf2-ARE pathway.
Assuntos
Envelhecimento , Encéfalo , Neurônios Dopaminérgicos , Comportamento Exploratório , Atividade Motora , Fator 2 Relacionado a NF-E2 , Propionato de Testosterona , Animais , Masculino , Ratos , Administração Intranasal , Envelhecimento/efeitos dos fármacos , Elementos de Resposta Antioxidante , Encéfalo/efeitos dos fármacos , Dopamina/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Comportamento Exploratório/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Atividade Motora/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/farmacologia , Substância Negra/efeitos dos fármacos , Propionato de Testosterona/farmacologia , Área Tegmentar Ventral/efeitos dos fármacosRESUMO
BACKGROUND: The two prevalent fixation methods in the treatment of syndesmosis injuries, the rigid screw fixation and flexible Endobutton fixation, are not without issues; thus, we have designed a novel bionic fixation method which combines the features of both rigid and flexible fixations. The aim of this study was to compare the biomechanical properties of the bionic fixation to the screw and Endobutton fixations. METHODS: Six normal fresh-frozen legs from amputation surgery were used. After initial tests of intact syndesmosis, screw, bionic and Endobutton fixations were performed sequentially for each specimen. Axial loading as well as rotation torque were applied, in five different ankle positions: neutral position, dorsiflexion, plantar flexion, varus, and valgus. The displacement of the syndesmosis and the tibial strain were analysed using a biomechanical testing system. RESULTS: Whether receiving axial loading or rotation torque, in most situations (neutral position, dorsiflexion, varus, plantar flexion with low loading, valgus with high loading, internal and external rotation), the bionic group and Endobutton group had comparable displacements, and there was no significant difference among the intact, bionic, and Endobutton groups; whereas the displacements of the screw group were smaller than any of the other three groups. Results of the tibial strain were similar with that of the displacement. CONCLUSIONS: The bionic fixation at least equals the performance of Endobutton fixation; it also allows more physiologic movement of the syndesmosis when compared to the screw fixation and may serve as a viable option for the fixation of the tibiofibular syndesmosis.
Assuntos
Fraturas do Tornozelo/cirurgia , Traumatismos do Tornozelo/cirurgia , Parafusos Ósseos , Fíbula/lesões , Fixação Interna de Fraturas/métodos , Tíbia/lesões , Adulto , Articulação do Tornozelo/fisiopatologia , Articulação do Tornozelo/cirurgia , Fenômenos Biomecânicos , Biônica , Cadáver , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
PURPOSE: The separation and sparing of the vesical branch of the inferior hypogastric plexus (IHP), to preserve the pelvic autonomic nerve, is critical and difficult in nerve sparing radical hysterectomy. Pelvic local anatomy was performed to provide the necessary anatomical information. METHODS: Precise pelvic anatomy was performed in 15 adult corpses, and immunohistochemical analysis was carried out on the parametrial tissues of three fresh cadavers to analyze the nerve fiber type and content of the vesical branch of the IHP. RESULTS: The deep uterine vein is located in the upper region of the cardinal ligament (CL), with three to six multiple branches and anatomical variation, including one or two cervical branches, and two to four vesical branches. Three branches were found to be most common (63.3 %). The major distribution of the vesical branch of the IHP is dorsomedial to the middle and inferior vesical veins, with less ventral and lateral distribution. There are more sympathetic fibers than parasympathetic fibers in the vesical branch. There is a region rare of vasculature and nerve between the vaginal lateral margin and the vesical branch. CONCLUSION: The deep uterine vein is suggested as an anatomical landmark during surgery, to process the CL and preserve the pelvic splanchnic nerves. The middle and inferior vesical veins can be used as the landmark to preserve the vesical branch of the IHP.
Assuntos
Plexo Hipogástrico/anatomia & histologia , Histerectomia/métodos , Pelve/inervação , Adulto , Cadáver , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-IdadeRESUMO
Topoisomerase IIß (top IIß) is a nuclear enzyme with an essential role in neural development. The regulation of top IIß gene expression during neural differentiation is poorly understood. Functional analysis of top IIß gene structure displayed a GC box sequence in its transcription promoter, which binds the nuclear transcription factor specificity protein 1 (Sp1). Sp1 regulates gene expression via multiple mechanisms and is essential for early embryonic development. This study seeks to determine whether Sp1 regulates top IIß gene expression during neuronal differentiation. For this purpose, human neuroblastoma SH-SY5Y cells were induced to neuronal differentiation in the presence of all-trans retinoic acid (RA) for 5 days. After incubation with 10 µM RA for 3-5 days, a majority of the cells exited the cell cycle to become postmitotic neurons, characterized by the presence of longer neurite outgrowths and expression of the neuronal marker microtubule-associated protein-2 (MAP2). Elevated Sp1 and top IIß mRNA and protein levels were detected and found to be positively correlated with the differentiation stage. Chromatin immunoprecipitation assay demonstrated an increased recruitment of Sp1 to the top IIß promoter after RA treatment. Mithramycin A, a compound that interferes with Sp1 binding to GC-rich DNA sequences, downregulated the expression of top IIß, resulting in reduced expression of MAP2 and decreased neurite length compared with the control group. Our results indicate that Sp1 regulates top IIß expression by binding to the GC box of the gene promoter during neuronal differentiation in SH-SY5Y cells.
Assuntos
Diferenciação Celular/fisiologia , DNA Topoisomerases Tipo II/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação Neoplásica da Expressão Gênica/fisiologia , Neurônios/metabolismo , Fator de Transcrição Sp1/metabolismo , Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , DNA Topoisomerases Tipo II/genética , Proteínas de Ligação a DNA/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Ceratolíticos/farmacologia , Neuritos/efeitos dos fármacos , Neuritos/fisiologia , Neuroblastoma/patologia , Neurônios/citologia , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia , RNA Mensageiro/metabolismo , Fator de Transcrição Sp1/genética , Tretinoína/farmacologiaRESUMO
The senescence-accelerated-prone mouse 8 (SAMP8) has been proposed as a suitable, naturally derived animal model for Alzheimer's disease (AD). In the current study, we focus on the problem whether SAMP8 mice show abnormal behavioral and neuropathological signs before they present the characteristic of AD. Our results demonstrated that given the presence of the senescent, behavioral and neuropathological characteristics, the "middle-aged" SAMP8 mice appear to be a suitable and naturally derived animal model for MCI basic research. There is relatively less evidence that androgen may be involved in the pathogenesis of AD. We determined testosterone (T) levels of SAMR1 and SAMP8 mice and found that the marked age-related decrease in serum androgen levels may be one of the risk factors for Alzheimer's dementia. We also evaluated the interventional effect on MCI phase by dihydrotestosterone (DHT) in male SAMP8 mice and found that timely and appropriate androgen intervention can postpone the onset and improve the symptoms of dementia.
Assuntos
Envelhecimento/patologia , Doença de Alzheimer/tratamento farmacológico , Disfunção Cognitiva/tratamento farmacológico , Di-Hidrotestosterona/uso terapêutico , Envelhecimento/fisiologia , Doença de Alzheimer/patologia , Doença de Alzheimer/psicologia , Animais , Encéfalo/patologia , Região CA1 Hipocampal/patologia , Disfunção Cognitiva/patologia , Disfunção Cognitiva/psicologia , Progressão da Doença , Feminino , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Especificidade da Espécie , Testosterona/sangueRESUMO
BACKGROUND: Spinal cord injury (SCI) is a serious clinical condition that has pathological changes such as increased neuroinflammation and nerve tissue damage, which eventually manifests as fibrosis of the injured segment and the development of a spinal cord cavity leading to loss of function. Cell-based therapy, such as mesenchymal stem cells (MSCs) and neural stem cells (NSCs) are promising treatment strategies for spinal cord injury via immunological regulation and neural replacement respectively. However, therapeutic efficacy is rare reported on combined transplantation of MSC and NSC in acute mice spinal cord injury even the potential reinforcement might be foreseen. Therefore, this study was conducted to investigate the safety and efficacy of co-transplanting of MSC and NSC sheets into an SCI mice model on the locomotor function and pathological changes of injured spinal cord. METHODS: To evaluate the therapeutic effects of combination cells, acute SCI mice model were established and combined transplantation of hiPSC-NSCs and hMSCs into the lesion site immediately after the injury. Basso mouse scale was used to perform the open-field tests of hind limb motor function at days post-operation (dpo) 1, 3, 5, and 7 after SCI and every week after surgery. Spinal cord and serum samples were collected at dpo 7, 14, and 28 to detect inflammatory and neurotrophic factors. Hematoxylin-eosin (H&E) staining, masson staining and transmission electron microscopy were used to evaluate the morphological changes, fibrosis area and ultrastructure of the spinal cord. RESULT: M&N transplantation reduced fibrosis formation and the inflammation level while promoting the secretion of nerve growth factor and brain-derived neurotrophic factor. We observed significant reduction in damaged tissue and cavity area, with dramatic improvement in the M&N group. Compared with the Con group, the M&N group exhibited significantly improved behaviors, particularly limb coordination. CONCLUSION: Combined transplantation of hiPSC-NSC and hMSC could significantly ameliorate neuroinflammation, promote neuroregeneration, and decrease spinal fibrosis degree in safe and effective pattern, which would be indicated as a novel potential cell treatment option.
Assuntos
Células-Tronco Pluripotentes Induzidas , Traumatismos da Medula Espinal , Animais , Camundongos , Doenças Neuroinflamatórias , Traumatismos da Medula Espinal/terapia , Modelos Animais de Doenças , FibroseRESUMO
Fragile X syndrome (FXS) is caused by epigenetic silencing of the Fmr1 gene, leading to the deletion of the coding protein FMRP. FXS induces abnormal hippocampal autophagy and mTOR overactivation. However, it remains unclear whether FMRP regulates hippocampal autophagy through the AKT/mTOR pathway, which influences the neural behavior of FXS. Our study revealed that FMRP deficiency increased the protein levels of p-ULK-1 and p62 and decreased LC3II/LC3I level in Fmr1 knockout (KO) mice. The mouse hippocampal neuronal cell line HT22 with knockdown of Fmr1 by lentivirus showed that the protein levels of p-ULK-1 and p62 were increased, whereas LC3II/LC3I was unchanged. Further observations revealed that FMRP deficiency obstructed autophagic flow in HT22 cells. Therefore, FMRP deficiency inhibited autophagy in the mouse hippocampus and HT22 cells. Moreover, FMRP deficiency increased reactive oxygen species (ROS) level, decreased the co-localization between the mitochondrial outer membrane proteins TOM20 and LC3 in HT22 cells, and caused a decrease in the mitochondrial autophagy protein PINK1 in HT22 cells and Fmr1 KO mice, indicating that FMRP deficiency caused mitochondrial autophagy disorder in HT22 cells and Fmr1 KO mice. To explore the mechanism by which FMRP deficiency inhibits autophagy, we examined the AKT/mTOR signaling pathway in the hippocampus of Fmr1 KO mice, found that FMRP deficiency caused overactivation of the AKT/mTOR pathway. Rapamycin-mediated mTOR inhibition activated and enhanced mitochondrial autophagy. Finally, we examined whether rapamycin affected the neurobehavior of Fmr1 KO mice. The Fmr1 KO mice exhibited stereotypical behavior, impaired social ability, and learning and memory impairment, while rapamycin treatment improved behavioral disorders in Fmr1 KO mice. Thus, our study revealed the molecular mechanism by which FMRP regulates autophagy function, clarifying the role of hippocampal neuron mitochondrial autophagy in the pathogenesis of FXS, and providing novel insights into potential therapeutic targets of FXS.
Assuntos
Autofagia , Proteína do X Frágil da Deficiência Intelectual , Síndrome do Cromossomo X Frágil , Hipocampo , Camundongos Knockout , Proteínas Proto-Oncogênicas c-akt , Transdução de Sinais , Serina-Treonina Quinases TOR , Animais , Masculino , Camundongos , Autofagia/fisiologia , Linhagem Celular , Proteína do X Frágil da Deficiência Intelectual/genética , Proteína do X Frágil da Deficiência Intelectual/metabolismo , Síndrome do Cromossomo X Frágil/metabolismo , Síndrome do Cromossomo X Frágil/patologia , Hipocampo/metabolismo , Hipocampo/patologia , Camundongos Endogâmicos C57BL , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/metabolismoRESUMO
Apolipoprotein E4 (APOE4), although yet-to-be fully understood, increases the risk and lowers the age of onset of Alzheimer's disease (AD), which is the major cause of dementia among elderly individuals. The endosome-lysosome and autophagy pathways, which are necessary for homeostasis in both neurons and glia, are dysregulated even in early AD. Nonetheless, the contributory roles of these pathways to developing AD-related pathologies in APOE4 individuals and models are unclear. Therefore, this review summarizes the dysregulations in the endosome-lysosome and autophagy pathways in APOE4 individuals and non-human models, and how these anomalies contribute to developing AD-relevant pathologies. The available literature suggests that APOE4 causes endosomal enlargement, increases endosomal acidification, impairs endosomal recycling, and downregulates exosome production. APOE4 impairs autophagy initiation and inhibits basal autophagy and autophagy flux. APOE4 promotes lysosome formation and trafficking and causes ApoE to accumulate in lysosomes. APOE4-mediated changes in the endosome, autophagosome and lysosome could promote AD-related features including Aß accumulation, tau hyperphosphorylation, glial dysfunction, lipid dyshomeostasis, and synaptic defects. ApoE4 protein could mediate APOE4-mediated endosome-lysosome-autophagy changes. ApoE4 impairs vesicle recycling and endosome trafficking, impairs the synthesis of autophagy genes, resists being dissociated from its receptors and degradation, and forms a stable folding intermediate that could disrupt lysosome structure. Drugs such as molecular correctors that target ApoE4 molecular structure and enhance autophagy may ameliorate the endosome-lysosome-autophagy-mediated increase in AD risk in APOE4 individuals.
Assuntos
Doença de Alzheimer , Apolipoproteína E4 , Idoso , Humanos , Alelos , Doença de Alzheimer/patologia , Apolipoproteína E4/genética , Apolipoproteína E4/metabolismo , Autofagia/genética , Endossomos/metabolismo , Lisossomos/metabolismoRESUMO
Parkinson's disease is a common neurodegenerative disorder. Here we present a human induced pluripotent stem cells (iPSCs) derived from peripheral blood mononuclear cells (PBMCs) of a 79-year-old female patient diagnosed with sporadic Parkinson's disease using the sendai virus. Generated iPSCs maintain normal karyotype, exhibit pluripotent stem cell markers, and possess differentiation potential. The iPSCs allows for differentiation into various cell subtypes, providing conditions for the research of the pathogenesis and drug development of Parkinson's disease.
Assuntos
Diferenciação Celular , Células-Tronco Pluripotentes Induzidas , Doença de Parkinson , Humanos , Feminino , Células-Tronco Pluripotentes Induzidas/metabolismo , Idoso , Doença de Parkinson/patologia , Doença de Parkinson/diagnóstico , Leucócitos Mononucleares/citologia , Linhagem Celular , CariótipoRESUMO
C9orf72 genetic mutation is the most common genetic cause of ALS/FTD accompanied by abnormal protein insufficiency. Induced pluripotent stem cell (iPSC)-derived two-dimensional (2D) and three-dimensional (3D) cultures are providing new approaches. Therefore, this study established neuronal cell types and generated spinal cord organoids (SCOs) derived from C9orf72 knockdown human iPSCs to model ALS disease and screen the unrevealed phenotype. Wild-type (WT) iPSC lines from three healthy donor fibroblasts were established, and pluripotency and differentiation ability were identified by RT-PCR, immunofluorescence and flow cytometry. After infection by the lentivirus with C9orf72-targeting shRNA, stable C9-knockdown iPSC colonies were selected and differentiated into astrocytes, motor neurons and SCOs. Finally, we analyzed the extracted RNA-seq data of human C9 mutant/knockout iPSC-derived motor neurons and astrocytes from the GEO database and the inflammatory regulation-related genes in function and pathways. The expression of inflammatory factors was measured by qRT-PCR. The results showed that both WT-iPSCs and edited C9-iPSCs maintained a similar ability to differentiate into the three germ layers, astrocytes and motor neurons, forming SCOs in a 3D culture system. The constructed C9-SCOs have features of spinal cord development and multiple neuronal cell types, including sensory neurons, motor neurons, and other neurons. Based on the bioinformatics analysis, proinflammatory factors were confirmed to be upregulated in C9-iPSC-derived 2D cells and 3D cultured SCOs. The above differentiated models exhibited low C9orf72 expression and the pathological characteristics of ALS, especially neuroinflammation.
Assuntos
Esclerose Lateral Amiotrófica , Diferenciação Celular , Células-Tronco Pluripotentes Induzidas , Neurônios Motores , Organoides , Medula Espinal , Células-Tronco Pluripotentes Induzidas/metabolismo , Humanos , Esclerose Lateral Amiotrófica/patologia , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Organoides/metabolismo , Organoides/patologia , Medula Espinal/patologia , Neurônios Motores/patologia , Neurônios Motores/metabolismo , Astrócitos/metabolismo , Astrócitos/patologia , Inflamação/patologia , Proteína C9orf72/genética , Proteína C9orf72/metabolismo , Modelos Biológicos , Neurônios/metabolismo , Neurônios/patologiaRESUMO
Aging-related reduction in androgen levels may be a possible risk factor for neurodegenerative diseases and contribute to cognitive impairment. Androgens may affect synaptic function and cognition in an androgen receptor (AR)-independent manner; however, the mechanisms connecting theses effects are unknown. Therefore, we used testicular feminization mutation (Tfm) male mice, a model with AR mutation, to test the effects of testosterone on synaptic function and cognition. Our results showed that testosterone ameliorated spatial memory deficit and neuronal damage, and increased dendritic spines density and postsynaptic density protein 95 (PSD95) and glutamate receptor 1 (GluA1) expression in the hippocampus of Tfm male mice. And these effects of testosterone were not inhibited by anastrozole, which suppressed conversion of testosterone to estradiol. Mechanistically, testosterone activated the extracellular signal-related kinase 1/2 (Erk1/2) and cyclic adenosine monophosphate response element-binding protein (CREB) in the hippocampus of Tfm male mice. Meanwhile, Erk1/2 inhibitor SCH772984 blocked the upregulation of phospho-CREB, PSD95, and GluA1 induced by testosterone in HT22 cells pretreated with flutamide, an androgen antagonist. Collectively, our data indicate that testosterone may ameliorate hippocampal synaptic damage and spatial memory deficit by activating the Erk1/2-CREB signaling pathway in an AR-independent manner.