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1.
CNS Neurosci Ther ; 30(4): e14529, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38013626

RESUMO

INTRODUCTION: Hereditary spastic paraplegias (HSPs) comprise a group of neurodegenerative disorders characterized by progressive degeneration of upper motor neurons. Homozygous or compound heterozygous variants in COQ4 have been reported to cause primary CoQ10 deficiency-7 (COQ10D7), which is a mitochondrial disease. AIMS: We aimed to screened COQ4 variants in a cohort of HSP patients. METHODS: A total of 87 genetically unidentified HSP index patients and their available family members were recruited. Whole exome sequencing (WES) was performed in all probands. Functional studies were performed to identify the pathogenicity of those uncertain significance variants. RESULTS: In this study, five different COQ4 variants were identified in three Chinese HSP pedigrees and two variants were novel, c.87dupT (p.Arg30*), c.304C>T (p.Arg102Cys). More importantly, we firstly described two early-onset pure HSP caused by COQ4 variants. Functional studies in patient-derived fibroblast lines revealed a reduction cellular CoQ10 levels and the abnormal mitochondrial structure. CONCLUSIONS: Our findings revealed that bilateral variants in the COQ4 gene caused HSP predominant phenotype, expanding the phenotypic spectrum of the COQ4-related disorders.


Assuntos
Doenças Mitocondriais , Paraplegia Espástica Hereditária , Humanos , Paraplegia Espástica Hereditária/genética , Mutação/genética , Fenótipo , Linhagem , Proteínas Mitocondriais/genética
2.
Zhongguo Zhen Jiu ; 43(7): 743-6, 2023 Jul 12.
Artigo em Chinês | MEDLINE | ID: mdl-37429651

RESUMO

OBJECTIVE: To observe the effect of buccal acupuncture on pain after lumbar spinal fusion. METHODS: Sixty patients undergoing lumbar spinal fusion were randomly divided into an observation group (30 cases, 1 case dropped off) and a control group (30 cases, 1 case was eliminated). The patients in the control group were treated with routine anesthesia. On the basis of the control group, the patients in the observation group were treated with buccal acupuncture at bilateral back point, waist point, and sacral point for 30 min per treatment. The first acupuncture was given before anesthesia induction, and then once a day postoperation for two days, totally 3 treatments. The dosage of sufentanil, the number of remedial analgesia, and the incidence of nausea and vomiting within 48 h after surgery were compared between the two groups; rest and motion visual analogue scale (VAS) scores at 2 (T1), 8 (T2), 12 (T3), 24 (T4), and 48 (T5) h after surgery were observed; the quality of recovery-15 scale (QoR-15) at 24 and 48 h after surgery were evaluated. RESULTS: The dosage of sufentanil and the number of remedial analgesia within 48 h after surgery in the observation group were lower than those in the control group (P<0.01). There was no significant statistically difference in rest and motion VAS scores between the two groups in T1, T2, T3, T4 and T5 (P>0.05). The QoR-15 scores in the observation group at 24 and 48 h after surgery were higher than those in the control group (P<0.01). The incidence of nausea in the observation group was lower than that in the control group (P<0.05). CONCLUSION: Buccal acupuncture could reduce the amount of postoperative analgesic drugs of patients after lumbar spinal fusion, and promote early postoperative recovery.


Assuntos
Terapia por Acupuntura , Fusão Vertebral , Humanos , Fusão Vertebral/efeitos adversos , Sufentanil , Manejo da Dor , Dor , Náusea
3.
Front Cell Dev Biol ; 10: 821848, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35903551

RESUMO

Individuals with intrauterine growth restriction (IUGR) are at an increased risk for neurodevelopmental impairment. Fetal cortical neurogenesis is a time-sensitive process in which fetal neural stem cells (NSCs) follow a distinct pattern of layer-specific neuron generation to populate the cerebral cortex. Here, we used a murine maternal hypoxia-induced IUGR model to study the impact of IUGR on fetal NSC development. In this model, timed-pregnant mice were exposed to hypoxia during the active stage of neurogenesis, followed by fetal brain collection and analysis. In the IUGR fetal brains, we found a significant reduction in cerebral cortical thickness accompanied by decreases in layer-specific neurons. Using EdU labeling, we demonstrated that cell cycle progression of fetal NSCs was delayed, primarily observed in the G2/M phase during inward interkinetic nuclear migration. Following relief from maternal hypoxia exposure, the remaining fetal NSCs re-established their neurogenic ability and resumed production of layer-specific neurons. Surprisingly, the newly generated neurons matched their control counterparts in layer-specific marker expression, suggesting preservation of the fetal NSC temporal identity despite IUGR effects. As expected, the absolute number of neurons generated in the IUGR group remained lower compared to that in the control group due to a reduced fetal NSC pool size as a result of cell cycle defect. Transcriptome analysis identified genes related to energy expenditure and G2/M cell cycle progression being affected by maternal hypoxia-induced IUGR. Taken together, maternal hypoxia-induced IUGR is associated with a defect in cell cycle progression of fetal NSCs, and has a long-term impact on offspring cognitive development.

5.
Front Genet ; 12: 746060, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34721532

RESUMO

Background: Mutations in superoxide dismutase 1 gene (SOD1) are the most frequent high penetrant genetic cause for amyotrophic lateral sclerosis (ALS) in the Chinese population. A detailed natural history of SOD1-mutated ALS patients will provide key information for ongoing genetic clinical trials. Methods: We screened for SOD1 mutations using whole exome sequencing (WES) in Chinese ALS cases from 2017 to 2021. Functional studies were then performed to confirm the pathogenicity of novel variants. In addition, we enrolled previously reported SOD1 mutations in our centers from 2007 to 2017. The SOD1 mutation spectrum, age at onset (AAO), diagnostic delay, and survival duration were analyzed. Results: We found two novel SOD1 variants (p.G17H and p.E134*) that exerted both gain-of-function and loss-of-function effects in vitro. Combined with our previous SOD1-mutated patients, 32 probands with 21 SOD1 mutations were included with the four most frequently occurring mutations of p.V48A, p.H47R, p.C112Y, and p.G148D. SOD1 mutations account for 58.9% of familial ALS (FALS) cases. The mean (SD) AAO was 46 ± 11.4 years with a significant difference between patients carrying mutations in exon 1 [n = 5, 34.6 (12.4) years] and exon 2 [n = 8, 51.4 (8.2) years] (p = 0.038). The mean of the diagnostic delay of FALS patients is significantly earlier than the sporadic ALS (SALS) patients [9.5 (4.8) vs. 20.3 (9.3) years, p = 0.0026]. In addition, male patients survived longer than female patients (40 vs. 16 months, p = 0.05). Conclusion: Our results expanded the spectrum of SOD1 mutations, highlighted the mutation distribution, and summarized the natural history of SOD1-mutated patients in southeastern China. Male patients were found to have better survival, and FALS patients received an earlier diagnosis. Our findings assist in providing a detailed clinical picture, which is important for ongoing genetic clinical trials.

7.
Genes (Basel) ; 12(3)2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-33668810

RESUMO

Gestational hypertensive disorders continue to threaten the well-being of pregnant women and their offspring. The only current definitive treatment for gestational hypertensive disorders is delivery of the fetus. The optimal timing of delivery remains controversial. Currently, the available clinical tools do not allow for assessment of fetal stress in its early stages. Placental insufficiency and fetal growth restriction secondary to gestational hypertensive disorders have been shown to have long-term impacts on offspring health even into their adulthood, becoming one of the major focuses of research in the field of developmental origins of health and disease. Fetal reprogramming was introduced to describe the long-lasting effects of the toxic intrauterine environment on the growing fetus. With the advent of high-throughput sequencing, there have been major advances in research attempting to quantify fetal reprogramming. Moreover, genes that are found to be differentially expressed as a result of fetal reprogramming show promise in the development of transcriptional biomarkers for clinical use in detecting fetal response to placental insufficiency. In this review, we will review key pathophysiology in the development of placental insufficiency, existing literature on high-throughput sequencing in the study of fetal reprogramming, and considerations regarding research design from our own experience.


Assuntos
Retardo do Crescimento Fetal/genética , Marcadores Genéticos , Insuficiência Placentária/genética , Análise de Sequência de DNA/métodos , Feminino , Desenvolvimento Fetal , Retardo do Crescimento Fetal/etiologia , Regulação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Insuficiência Placentária/etiologia , Gravidez
8.
Front Pediatr ; 8: 459, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32984199

RESUMO

Introduction: Timing of medical delivery of preterm newborns exposed to placental insufficiency is largely determined by umbilical artery blood flow and maternal clinical manifestations. There is a lack of tools to properly assess fetal body response to placental insufficiency before or upon delivery. Yet, short- and long-term comorbidities associated with placental insufficiency and the consequential intrauterine growth restriction may be a result of fetal response following prolonged stress. This study aims to establish a procedure to investigate fetal/neonatal transcriptional response to placental insufficiency as part of an initiative to identify cost-effective biomarkers for assessing fetal response to placental insufficiency. Methods: A prospective pilot study involving newborns with birth gestation <32 weeks was conducted to compare gene expression profiles in whole blood collected at birth among three clinically distinct groups - preeclampsia without placental insufficiency (PE), placental insufficiency (PI), and non-PE/PI groups. Results: Whole blood from 11, 3, and 6 newborns in the non-PE/PI, PE, and PI groups were obtained. A transcriptome analysis found that the majority of the genes were downregulated in the PI group, suggesting global transcriptional inactivation. Intriguingly, SLC25A42, which encodes a mitochondrial transporter for coenzyme A and adenosine-3',5'-diphosphate, was significantly upregulated in the PI group. Conclusion: Transcriptional biomarkers for assessing fetal response to placental insufficiency may provide a useful tool to better understand the pathophysiology of fetal reprogramming in response to placental insufficiency. The validity and the role of SLC25A42, as well as its correlation with short- and long-term neonatal outcomes, warrants further investigation.

9.
Bio Protoc ; 9(12): e3275, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-33654792

RESUMO

Cell motility has been extensively studied in in vitro models using fibroblasts and keratocytes, but the cell type-specific mechanisms underlying migration of lineage- or disease-specific cells, such as neural and glial progenitor cells, remain an active field for investigation. The migrating neural and glial progenitor cells contribute to the development, tissue repair and tumor invasion in the central nervous system (CNS). Cell migration is a highly dynamic process which relies on membranous protrusions to assemble, extend, disassemble and retract. In the CNS, the motility of neural and glial progenitor cells is affected by various cell-autonomous and non-cell-autonomous mechanisms such as signaling molecules, actin and microtubule interactions, and environmental cues. Here, we described a live-cell migration assay for use in the assessment of neural and glial progenitor cell migration. We first will demonstrate the procedures for isolating and culturing neural and glial progenitor cells. Next, we will demonstrate the acquisition of time-lapse images using phase contrast microscopy, the methods for quantification and the analyses of various motility parameters including speed, velocity, straightness and leading-edge dynamics. This method allows researchers to dissect the mechanisms of cell motility in response to different environmental cues, such as chemoattractive and repulsive signals, matrix adhesiveness and stiffness. This assay also allows researchers to study migration of pharmacologically and genetically manipulated cells.

10.
Methods Mol Biol ; 1749: 135-143, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29525995

RESUMO

Neuronal migration during fetal brain development is a well-coordinated process between the migrating neurons and their substrates, the basal processes of the radial glial cells (RGCs). The progeny-progenitor relationship between the migrating neurons and the RGCs in the developing fetal brain may make interpretations of the results difficult, because the variable in question may affect both the RGCs and the migrating neurons in different ways. A transplantation assay combining migrating cells and the scaffolding tissue from two different sources may circumvent this issue. We developed an ex vivo brain slice transplantation assay that allows recording of migrating neurons in real time.


Assuntos
Encéfalo/citologia , Movimento Celular/fisiologia , Neurônios/citologia , Técnicas de Cultura de Tecidos/métodos , Animais , Linhagem Celular , Células Cultivadas , Córtex Cerebral/citologia , Feminino , Humanos , Camundongos , Células-Tronco Neurais/citologia , Neurogênese/fisiologia , Gravidez
11.
Cell Mol Life Sci ; 75(6): 1027-1041, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29018869

RESUMO

Originating from ectodermal epithelium, radial glial cells (RGCs) retain apico-basolateral polarity and comprise a pseudostratified epithelial layer in the developing cerebral cortex. The apical endfeet of the RGCs faces the fluid-filled ventricles, while the basal processes extend across the entire cortical span towards the pial surface. RGC functions are largely dependent on this polarized structure and the molecular components that define it. In this review, we will dissect existing molecular evidence on RGC polarity establishment and during cerebral cortex development and provide our perspective on the remaining key questions.


Assuntos
Polaridade Celular , Córtex Cerebral/metabolismo , Ectoderma/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas do Tecido Nervoso/genética , Neuroglia/metabolismo , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/ultraestrutura , Junções Aderentes/metabolismo , Junções Aderentes/ultraestrutura , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Córtex Cerebral/citologia , Córtex Cerebral/crescimento & desenvolvimento , Ventrículos Cerebrais/citologia , Ventrículos Cerebrais/crescimento & desenvolvimento , Ventrículos Cerebrais/metabolismo , Ectoderma/citologia , Ectoderma/crescimento & desenvolvimento , Embrião de Mamíferos , Epitélio/crescimento & desenvolvimento , Epitélio/metabolismo , Matriz Extracelular/metabolismo , Matriz Extracelular/ultraestrutura , Humanos , Proteínas do Tecido Nervoso/metabolismo , Neuroglia/citologia , Pia-Máter/citologia , Pia-Máter/crescimento & desenvolvimento , Pia-Máter/metabolismo
12.
Development ; 143(15): 2741-52, 2016 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-27385014

RESUMO

The polarity and organization of radial glial cells (RGCs), which serve as both stem cells and scaffolds for neuronal migration, are crucial for cortical development. However, the cytoskeletal mechanisms that drive radial glial outgrowth and maintain RGC polarity remain poorly understood. Here, we show that the Arp2/3 complex - the unique actin nucleator that produces branched actin networks - plays essential roles in RGC polarity and morphogenesis. Disruption of the Arp2/3 complex in murine RGCs retards process outgrowth toward the basal surface and impairs apical polarity and adherens junctions. Whereas the former is correlated with an abnormal actin-based leading edge, the latter is consistent with blockage in membrane trafficking. These defects result in altered cell fate, disrupted cortical lamination and abnormal angiogenesis. In addition, we present evidence that the Arp2/3 complex is a cell-autonomous regulator of neuronal migration. Our data suggest that Arp2/3-mediated actin assembly might be particularly important for neuronal cell motility in a soft or poorly adhesive matrix environment.


Assuntos
Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo , Células Ependimogliais/citologia , Complexo 2-3 de Proteínas Relacionadas à Actina/genética , Animais , Apoptose/genética , Apoptose/fisiologia , Movimento Celular/genética , Movimento Celular/fisiologia , Polaridade Celular/genética , Polaridade Celular/fisiologia , Proliferação de Células/genética , Proliferação de Células/fisiologia , Células Ependimogliais/metabolismo , Camundongos , Morfogênese/genética , Morfogênese/fisiologia , Neurogênese/genética , Neurogênese/fisiologia , Neurônios/citologia , Neurônios/metabolismo
13.
Neurogenesis (Austin) ; 3(1): e1261653, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28405589

RESUMO

During development of the nervous system, radial glial cells perform self-renewing asymmetric divisions and give rise to intermediate progenitor cells (IPC) and neurons. The neuronally committed IPC subsequently undergo multiple rounds of transient amplification and migrate outwards to form cortical layers as they continue to differentiate into mature neurons. Maturing neurons extend protrusions on their cell surface to form neurites, a process called neuritogenesis. Neurite formation results in the establishment of dendrites and axons for synapse formation, which is essential for sensory and motor functions and even higher-level functioning including memory formation and cognitive function, as well as shaping of behavior and emotion. Morphological adaptation during various stages of neural development requires active participation of actin cytoskeleton remodeling. In this review, we aim to discuss current understanding of the Arp2/3 complex branching nucleator in various neural cell types during development and maturation.

14.
Stem Cell Res Ther ; 6: 41, 2015 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-25890209

RESUMO

INTRODUCTION: The loss of oligodendrocytes in a lesion of the central nervous system causes demyelination and therefore impairs axon function and survival. Transplantation of neural stem cell-derived oligodendrocyte precursor cells (NSC-OPCs) results in increased oligodendrocyte formation and enhanced remyelination. The directional migration of grafted cells to the target can promote the establishment of functional reconnection and myelination in the process of neural regeneration. Endogenous electric fields (EFs) that were detected in the development of the central nervous system can regulate cell migration. METHODS: NSCs were isolated from the brains of ARPC2+/+ and ARPC2-/- mouse embryo and differentiated into OPCs. After differentiation, the cultured oligospheres were stimulated with EFs (50, 100, or 200 mV/mm). The migration of OPCs from oligospheres was recorded using time-lapse microscopy. The cell migration directedness and speed were analyzed and quantified. RESULTS: In this study, we found that NSC-OPCs migrated toward the cathode pole in EFs. The directedness and displacement of cathodal migration increased significantly when the EF strength increased from 50 to 200 mV/mm. However, the EF did not significantly change the cell migration speed. We also showed that the migration speed of ARPC2-/- OPCs, deficient in the actin-related proteins 2 and 3 (ARP2/3) complex, was significantly lower than that of wild type of OPCs. ARPC2-/- OPCs migrated randomly in EFs. CONCLUSIONS: The migration direction of NSC-OPCs can be controlled by EFs. The function of the ARP complex is required for the cathodal migration of NSC-OPCs in EFs. EF-guided cell migration is an effective model to understanding the intracellular signaling pathway in the regulation of cell migration directness and motility.


Assuntos
Complexo 2-3 de Proteínas Relacionadas à Actina/genética , Movimento Celular/fisiologia , Campos Eletromagnéticos , Células-Tronco Neurais/transplante , Oligodendroglia/citologia , Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo , Animais , Diferenciação Celular , Células Cultivadas , Sistema Nervoso Central/citologia , Sistema Nervoso Central/lesões , Sistema Nervoso Central/metabolismo , Doenças Desmielinizantes , Camundongos , Camundongos Knockout , Bainha de Mielina/metabolismo , Células-Tronco Neurais/metabolismo
15.
Chin J Cancer ; 33(6): 306-16, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24823992

RESUMO

Previous studies suggested that smoking and passive smoking could increase the risk of breast cancer, but the results were inconsistent, especially for Chinese females. Thus, we systematically searched cohort and case-control studies investigating the associations of active and passive smoking with breast cancer risk among Chinese females in four English databases (PubMed, Embase, ScienceDirect, and Wiley) and three Chinese databases (CNKI, WanFang, and VIP). Fifty-one articles (3 cohort studies and 48 case-control studies) covering 17 provinces of China were finally included in this systematic review. Among Chinese females, there was significant association between passive smoking and this risk of breast cancer [odds ratio (OR): 1.62; 95% confidence interval (CI): 1.39-1.85; I2 = 75.8%, P < 0.001; n = 26] but no significant association between active smoking and the risk of breast cancer (OR: 1.04; 95% CI: 0.89-1.20; I2 = 13.9%, P = 0.248; n = 31). The OR of exposure to husband's smoking and to smoke in the workplace was 1.27 (95% CI: 1.07-1.50) and 1.66 (95% CI: 1.07-2.59), respectively. The OR of light and heavy passive smoking was 1.11 and 1.41, respectively, for women exposed to their husband's smoke (< 20 and ≥ 20 cigarettes per day), and 1.07 and 1.87, respectively, for those exposed to smoke in the workplace (< 300 and ≥ 300 min of exposure per day). These results imply that passive smoking is associated with an increased risk of breast cancer, and the risk seems to increase as the level of passive exposure to smoke increases among Chinese females. Women with passive exposure to smoke in the workplace have a higher risk of breast cancer than those exposed to their husband's smoking.


Assuntos
Neoplasias da Mama , Exposição Ocupacional , Poluição por Fumaça de Tabaco , China , Estudos de Coortes , Feminino , Humanos , Razão de Chances , Fatores de Risco , Fumar
16.
Asian Pac J Cancer Prev ; 15(3): 1291-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24606455

RESUMO

BACKGROUND: Evidence for associations between dietary factors and breast cancer risk is inconclusive among Chinese females. To evaluate this question, we conducted a systematic review of relevant case-control and cohort studies. METHODS: Studies were systematically searched among 5 English databases (PudMed, ScienceDirect, Wiley, Clinicaltrials.gov, and Cochrane) and 3 Chinese databases (CNKI, WanFang, and VIP) until November 2012. Random effects models were used to estimate summary odds ratios (ORs) and the corresponding 95% confidence intervals (CIs). RESULTS: Thirty one case-control studies and two cohort studies involving 9,299 cases and 11,413 controls were included. Consumption of both soy and fruit was significantly associated with decreased risk of breast cancer, with summary ORs of 0.65 (95% CIs: 0.43-0.99; I2=88.9%, P<0.001; N=13) and 0.66 (95% CIs: 0.47-0.91; I2=76.7%, P<0.001; N=7), respectively. Consumption of fat was significantly associated with increased risk of breast cancer (OR=1.36; 95% CIs: 1.13-1.63; I2=47.9%, P=0.088; N=6). There was non- significant association between consumption of vegetables and breast cancer risk (OR=0.72; 95% CIs: 0.51-1.02; I2= 74.4%, P<0.001; N=9). However, sensitivity analysis based on adjusted ORs showed decreased risk of breast cancer was also associated with consumption of vegetables (OR=0.49; 95% CIs: 0.30-0.67). CONCLUSION: Both soy food and fruit are significantly associated with decreased risk of breast cancer among Chinese females, and vegetables also seems to be protective while dietary fatexerts a promoting influence.


Assuntos
Neoplasias da Mama/dietoterapia , Gorduras na Dieta/efeitos adversos , Comportamento Alimentar , Neoplasias da Mama/prevenção & controle , China , Feminino , Frutas , Humanos , Fatores de Risco , Alimentos de Soja
17.
J Biol Chem ; 287(15): 12529-40, 2012 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-22354965

RESUMO

Tightly controlled termination of proliferation determines when oligodendrocyte progenitor cells (OPCs) can initiate differentiation and mature into myelin-forming cells. Protein-tyrosine phosphatase α (PTPα) promotes OPC differentiation, but its role in proliferation is unknown. Here we report that loss of PTPα enhanced in vitro proliferation and survival and decreased cell cycle exit and growth factor dependence of OPCs but not neural stem/progenitor cells. PTPα(-/-) mice have more oligodendrocyte lineage cells in embryonic forebrain and delayed OPC maturation. On the molecular level, PTPα-deficient mouse OPCs and rat CG4 cells have decreased Fyn and increased Ras, Cdc42, Rac1, and Rho activities, and reduced expression of the Cdk inhibitor p27Kip1. Moreover, Fyn was required to suppress Ras and Rho and for p27Kip1 accumulation, and Rho inhibition in PTPα-deficient cells restored expression of p27Kip1. We propose that PTPα-Fyn signaling negatively regulates OPC proliferation by down-regulating Ras and Rho, leading to p27Kip1 accumulation and cell cycle exit. Thus, PTPα acts in OPCs to limit self-renewal and facilitate differentiation.


Assuntos
Proliferação de Células , Células-Tronco Neurais/fisiologia , Oligodendroglia/fisiologia , Proteínas Tirosina Fosfatases Classe 4 Semelhantes a Receptores/metabolismo , Animais , Apoptose , Encéfalo/citologia , Encéfalo/enzimologia , Encéfalo/crescimento & desenvolvimento , Ciclo Celular , Sobrevivência Celular , Células Cultivadas , Inibidor de Quinase Dependente de Ciclina p27/genética , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Fator 2 de Crescimento de Fibroblastos/fisiologia , Técnicas de Inativação de Genes , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células-Tronco Neurais/metabolismo , Neuropeptídeos/metabolismo , Fator de Crescimento Derivado de Plaquetas/fisiologia , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Ratos , Proteínas Tirosina Fosfatases Classe 4 Semelhantes a Receptores/genética , Transdução de Sinais , Esferoides Celulares/fisiologia , Regulação para Cima , Proteína cdc42 de Ligação ao GTP/metabolismo , Proteínas rac de Ligação ao GTP/metabolismo , Proteínas rac1 de Ligação ao GTP , Proteínas rho de Ligação ao GTP/antagonistas & inibidores , Proteínas rho de Ligação ao GTP/metabolismo
18.
Cancer Res ; 71(16): 5569-78, 2011 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-21730024

RESUMO

The Y-box binding protein 1 (YB-1) is upregulated in many human malignancies including glioblastoma (GBM). It is also essential for normal brain development, suggesting that YB-1 is part of a neural stem cell (NSC) network. Here, we show that YB-1 was highly expressed in the subventricular zone (SVZ) of mouse fetal brain tissues but not in terminally differentiated primary astrocytes. Conversely, YB-1 knockout mice had reduced Sox-2, nestin, and musashi-1 expression in the SVZ. Although primary murine neurospheres were rich in YB-1, its expression was lost during glial differentiation. Glial tumors often express NSC markers and tend to loose the cellular control that governs differentiation; therefore, we addressed whether YB-1 served a similar role in cancer cells. YB-1, Sox-2, musashi-1, Bmi-1, and nestin are coordinately expressed in SF188 cells and 9/9 GBM patient-derived primary brain tumor-initiating cells (BTIC). Silencing YB-1 with siRNA attenuated the expression of these NSC markers, reduced neurosphere growth, and triggered differentiation via coordinate loss of GSK3-ß. Furthermore, differentiation of BTIC with 1% serum or bone morphogenetic protein-4 suppressed YB-1 protein expression. Likewise, YB-1 expression was lost during differentiation of normal human NSCs. Consistent with these observations, YB-1 expression increased with tumor grade (n = 49 cases). YB-1 was also coexpressed with Bmi-1 (Spearmans 0.80, P > 0.001) and Sox-2 (Spearmans 0.66, P > 0.001) based on the analysis of 282 cases of high-grade gliomas. These proteins were highly expressed in 10/15 (67%) of GBM patients that subsequently relapsed. In conclusion, YB-1 correlatively expresses with NSC markers where it functions to promote cell growth and inhibit differentiation.


Assuntos
Neoplasias Encefálicas/patologia , Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , Glioblastoma/patologia , Células-Tronco Neurais/citologia , Fatores de Transcrição/fisiologia , Animais , Sequência de Bases , Linhagem Celular Tumoral , Imuno-Histoquímica , Camundongos , Camundongos Knockout , RNA Interferente Pequeno
19.
J Biol Chem ; 284(48): 33692-702, 2009 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-19812040

RESUMO

The tyrosine kinase Fyn plays a key role in oligodendrocyte differentiation and myelination in the central nervous system, but the molecules responsible for regulating Fyn activation in these processes remain poorly defined. Here we show that receptor-like protein-tyrosine phosphatase alpha (PTPalpha) is an important positive regulator of Fyn activation and signaling that is required for the differentiation of oligodendrocyte progenitor cells (OPCs). PTPalpha is expressed in OPCs and is up-regulated during differentiation. We used two model systems to investigate the role of PTPalpha in OPC differentiation: the rat CG4 cell line where PTPalpha expression was silenced by small interfering RNA, and oligosphere-derived primary OPCs isolated from wild-type and PTPalpha-null mouse embryos. In both cell systems, the ablation of PTPalpha inhibited differentiation and morphological changes that accompany this process. Although Fyn was activated upon induction of differentiation, the level of activation was severely reduced in cells lacking PTPalpha, as was the activation of Fyn effector molecules focal adhesion kinase, Rac1, and Cdc42, and inactivation of Rho. Interestingly, another downstream effector of Fyn, p190RhoGAP, which is responsible for Rho inactivation during differentiation, was not affected by PTPalpha ablation. In vivo studies revealed defective myelination in the PTPalpha(-/-) mouse brain. Together, our findings demonstrate that PTPalpha is a critical regulator of Fyn activation and of specific Fyn signaling events during differentiation, and is essential for promoting OPC differentiation and central nervous system myelination.


Assuntos
Diferenciação Celular , Oligodendroglia/metabolismo , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Proteínas Tirosina Fosfatases Classe 4 Semelhantes a Receptores/metabolismo , Transdução de Sinais , Animais , Encéfalo/metabolismo , Linhagem Celular , Células Cultivadas , Quinase 1 de Adesão Focal/metabolismo , Immunoblotting , Camundongos , Camundongos Knockout , Microscopia de Fluorescência , Bainha de Mielina/metabolismo , Oligodendroglia/citologia , Fosforilação , Interferência de RNA , Proteínas Tirosina Fosfatases Classe 4 Semelhantes a Receptores/genética , Proteína cdc42 de Ligação ao GTP/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo
20.
J Surg Res ; 153(2): 210-6, 2009 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-18639247

RESUMO

BACKGROUND: Thiazolidinediones (TZDs) have been demonstrated to possess antitumor effects in breast cancer cells, although the mechanisms are not well established. We sought to better define TZDs' antitumor effects and molecular mechanisms to permit rational utilization of these agents. MATERIALS AND METHODS: We studied the effects of TZDs on DNA synthesis (BrdU enzyme-linked immunosorbent assay), gene expression (microarray, quantitative reverse transcription-polymerase chain reaction, and immunoblot), serine phosphorylation and localization of beta-catenin (nuclear/cytoplasmic fractionation and immunoblot), transactivation activity of beta-catenin/T cell factor 4 (TCF4) (luciferase assay with wild-type and mutant TCF4 responsive element), and beta-catenin/TCF4 complex (immunoprecipitation) in human breast cancer cells MDA-MB-231 and T47D. RESULTS: Troglitazone (TG) down-regulated DNA synthesis in MDA-MB-231 and T47D and decreased mRNA expression of the Wnt co-receptors frizzled-1 and low-density lipoprotein-related protein 6 (LRP6) as well as protein level of LRP6. TG also targets downstream Wnt signaling molecules in T47D cells. TG down-regulates p-beta-catenin (S33/S37/T41) and promotes translocation of beta-catenin into the nucleus. However, TG inhibits beta-catenin-mediated transactivation by down-regulating TCF4 protein levels, thereby inhibiting beta-catenin/TCF4 complex formation. Finally, we found that inhibition of Akt augments TG-mediated down-regulation of DNA synthesis and this result was accompanied with the decreased protein levels of Wnt signaling molecules: LRP6, beta-catenin, and TCF4. CONCLUSION: These results suggest that the Wnt/beta-catenin signaling pathway, which plays an important role in breast cancer pathogenesis, may be a target for TZD treatment. Moreover, a combination of TZDs and a specific Akt inhibitor may serve as a new approach to target Wnt/beta-catenin directly and via PI3K/Akt action on glycogen synthase-3beta.


Assuntos
Neoplasias da Mama/metabolismo , Transdução de Sinais/efeitos dos fármacos , Tiazolidinedionas/farmacologia , Proteínas Wnt/metabolismo , beta Catenina/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Replicação do DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Regulação para Baixo/efeitos dos fármacos , Receptores Frizzled/metabolismo , Humanos , Proteínas Relacionadas a Receptor de LDL/metabolismo , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Tiazolidinedionas/uso terapêutico , Fator de Transcrição 4 , Fatores de Transcrição/metabolismo , Regulação para Cima
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