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1.
Proc Natl Acad Sci U S A ; 120(3): e2218332120, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36626549

RESUMO

O-GlcNAc transferase (OGT) modifies serine and threonine residues on nuclear and cytosolic proteins with O-linked N-acetylglucosamine (GlcNAc). OGT is essential for mammalian cell viability, but the underlying mechanisms are still enigmatic. We performed a genome-wide CRISPR-Cas9 screen in mouse embryonic stem cells (mESCs) to identify candidates whose depletion rescued the block in cell proliferation induced by OGT deficiency. We show that the block in cell proliferation in OGT-deficient cells stems from mitochondrial dysfunction secondary to mTOR (mechanistic target of rapamycin) hyperactivation. In normal cells, OGT maintains low mTOR activity and mitochondrial fitness through suppression of proteasome activity; in the absence of OGT, increased proteasome activity results in increased steady-state amino acid levels, which in turn promote mTOR lysosomal translocation and activation, and increased oxidative phosphorylation. mTOR activation in OGT-deficient mESCs was confirmed by an independent phospho-proteomic screen. Our study highlights a unique series of events whereby OGT regulates the proteasome/ mTOR/ mitochondrial axis in a manner that maintains homeostasis of intracellular amino acid levels, mitochondrial fitness, and cell viability. A similar mechanism operates in CD8+ T cells, indicating its generality across mammalian cell types. Manipulating OGT activity may have therapeutic potential in diseases in which this signaling pathway is impaired.


Assuntos
Linfócitos T CD8-Positivos , Complexo de Endopeptidases do Proteassoma , Animais , Camundongos , Acetilglucosamina/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Sobrevivência Celular , Mitocôndrias/metabolismo , N-Acetilglucosaminiltransferases/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteômica , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
2.
EMBO Rep ; 22(8): e52716, 2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34288360

RESUMO

TET methylcytosine dioxygenases are essential for the stability and function of regulatory T cells (Treg cells), which maintain immune homeostasis and self-tolerance and express the lineage-determining transcription factor Foxp3. Here, we use whole-genome analyses to show that the transcriptional program and epigenetic features (DNA modification, chromatin accessibility) of Treg cells are attenuated in the absence of Tet2 and Tet3. Conversely, the addition of the TET activator vitamin C during TGFß-induced iTreg cell differentiation in vitro potentiates the expression of Treg signature genes and alters the epigenetic landscape to better resemble that of Treg cells generated in vivo. Vitamin C enhances IL-2 responsiveness in iTreg cells by increasing IL2Rα expression, STAT5 phosphorylation, and STAT5 binding, mimicking the IL-2/STAT5 dependence of Treg cells generated in vivo. In summary, TET proteins play essential roles in maintaining Treg molecular features and promoting their dependence on IL-2. TET activity during endogenous Treg development and potentiation of TET activity by vitamin C during iTreg differentiation are necessary to maintain the transcriptional and epigenetic features of Treg cells.


Assuntos
Dioxigenases , Linfócitos T Reguladores , Diferenciação Celular/genética , Fatores de Transcrição Forkhead/metabolismo , Regulação da Expressão Gênica , Linfócitos T Reguladores/metabolismo , Fator de Crescimento Transformador beta/metabolismo
3.
BMC Pediatr ; 23(1): 173, 2023 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-37055789

RESUMO

BACKGROUND: This study evaluated vitamin A (VA), copper (Cu), and zinc (Zn) levels in the population with autism spectrum disorder (ASD) in Jilin Province, China. Furthermore, we examined their links to core symptoms and neurodevelopment, as well as gastrointestinal (GI) comorbidities and sleep disorders. METHODS: This study included 181 children with autism and 205 typically developing (TD) children. The participants had not taken vitamin/mineral supplements in the prior three months. High-performance liquid chromatography was used to measure serum VA levels. By using inductively coupled plasma-mass spectrometry, Zn and Cu concentrations in plasma were determined. Importantly, the Childhood Autism Rating Scale, the Social Responsiveness Scale, and the Autism Behavior Checklist were used to measure core ASD symptoms. However, the Griffith Mental Development Scales-Chinese were used to measure neurodevelopment. GI comorbidities and sleep abnormalities were assessed with the 6 Item-Gastrointestinal Severity Index and Children's Sleep Habits Questionnaire, respectively. Children with ASD with GI issues were grouped according to severity (low GI severity and high GI severity groups). RESULTS: (i) The difference in VA, Zn, Cu levels and the Zn/Cu ratio between ASD and TD children is small. But children with ASD had lower VA levels and Zn/Cu ratio, higher Cu levels than TD children. Cu levels in children with ASD were associated with the severity of core symptoms. (ii) Children with ASD were much more likely than their TD counterparts to suffer from GI comorbidities or sleep problems. Furthermore, it was observed that high GI severity was associated with lower levels of VA, whereas low GI severity was associated with higher levels of VA. (iii) The children with ASD who had both lower VA and lower Zn/Cu ratio had more severe scores on the Autism Behavior Checklist, but not on other measures. CONCLUSION: Children with ASD had lower VA and Zn/Cu ratio, and higher Cu levels. Cu levels in children with ASD were weakly correlated with one subscale on social or self-help. ASD children with lower VA levels may face more serious GI comorbidities. Children with ASD combined VA-Zn/Cu lower had more severe core symptoms. TRIAL REGISTRATION: Registration number: ChiCTR-OPC-17013502. Date of registration: 2017-11-23.


Assuntos
Transtorno do Espectro Autista , Humanos , Criança , Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/complicações , Vitamina A , Cobre , Zinco , Vitaminas
4.
J Cell Mol Med ; 26(5): 1629-1642, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35137520

RESUMO

The decreased expression of tumour suppressor candidate 3 (TUSC3) is associated with proliferation in several types of cancer, leading to an unfavourable prognosis. The present study aimed to assess the cellular and molecular function of TUSC3 in patients with cervical squamous cell carcinoma (CSCC). Levels of mRNA expressions of TUSC3 were analysed in CSCC tissues and six cell lines using qRT-PCR. Immunohistochemistry(IHC) was used to evaluate the protein expression level of TUSC3 in four paired specimens, 220 paraffin-embedded CSCC specimens and 60 cases of normal cervical tissues(NCTs), respectively. Short hairpin RNA interference was employed for TUSC3 knockdown. Cell proliferation, migration and invasion were evaluated using growth curve, MTT assay, wound healing, transwell assay and xenograft tumour model, respectively. The results demonstrated that TUSC3 mRNA and protein expression levels were downregulated in CSCC samples. Multivariate and univariate analyses indicated that TUSC3 was an independent prognostic factor for patients with CSCC. Decreased TUSC3 expression levels were significantly associated with proliferation and an aggressive phenotype of cervical cancer cells both in vitro and in vivo. Moreover, the knockdown of TUSC3 promoted migration and invasion of cancer cells, while the increased expression of TUSC3 exhibited the opposite effects. The downregulation of TUSC3 facilitated proliferation and invasion of CSCC cells through the activation of the AKT signalling pathway. Our data demonstrated that the downregulation of TUSC3 promoted CSCC cell metastasis via the AKT signalling pathway. Therefore, TUSC3 may serve as a novel prognostic marker and potential target for CSCC.


Assuntos
Carcinoma de Células Escamosas , Neoplasias do Colo do Útero , Feminino , Humanos , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Proteínas de Membrana , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , Proteínas Supressoras de Tumor , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia
5.
Blood ; 136(12): 1394-1401, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32730592

RESUMO

Vitamin C serves as a cofactor for Fe(II) and 2-oxoglutarate-dependent dioxygenases including TET family enzymes, which catalyze the oxidation of 5-methylcytosine into 5-hydroxymethylcytosine and further oxidize methylcytosines. Loss-of-function mutations in epigenetic regulators such as TET genes are prevalent in hematopoietic malignancies. Vitamin C deficiency is frequently observed in cancer patients. In this review, we discuss the role of vitamin C and TET proteins in cancer, with a focus on hematopoietic malignancies, T regulatory cells, and other immune system cells.


Assuntos
Ácido Ascórbico/imunologia , Dioxigenases/imunologia , Imunidade , Neoplasias/imunologia , Animais , Deficiência de Ácido Ascórbico/complicações , Deficiência de Ácido Ascórbico/imunologia , Deficiência de Ácido Ascórbico/fisiopatologia , Humanos , Ácidos Cetoglutáricos/imunologia , Leucopoese , Neoplasias/complicações , Neoplasias/fisiopatologia , Linfócitos T Reguladores/imunologia
6.
FASEB J ; 35(6): e21555, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34046947

RESUMO

Preeclampsia (PE) is a life-threatening disease of pregnant women associated with severe hypertension, proteinuria, or multi-organ injuries. Mitochondrial-mediated placental oxidative stress plays a key role in the pathogenesis of PE. However, the underlying mechanism remains to be revealed. Here, we identify Rnd3, a small Rho GTPase, regulating placental mitochondrial reactive oxygen species (ROS). We showed that Rnd3 is down-regulated in primary trophoblasts isolated from PE patients. Loss of Rnd3 in trophoblasts resulted in excessive ROS generation, cell apoptosis, mitochondrial injury, and proton leakage from the respiratory chain. Moreover, Rnd3 overexpression partially rescues the mitochondrial defects and oxidative stress in human PE primary trophoblasts. Rnd3 physically interacts with the peroxisome proliferators-activated receptor γ (PPARγ) and promotes the PPARγ-mitochondrial uncoupling protein 2 (UCP2) cascade. Forced expression of PPARγ rescues deficiency of Rnd3-mediated mitochondrial dysfunction. We conclude that Rnd3 acts as a novel protective factor in placental mitochondria through PPARγ-UCP2 signaling and highlight that downregulation of Rnd3 is a potential factor involved in PE pathogenesis.


Assuntos
Mitocôndrias/patologia , PPAR gama/metabolismo , Placenta/patologia , Pré-Eclâmpsia/patologia , Trofoblastos/patologia , Proteína Desacopladora 2/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Feminino , Humanos , Mitocôndrias/metabolismo , Estresse Oxidativo , PPAR gama/genética , Placenta/metabolismo , Pré-Eclâmpsia/genética , Pré-Eclâmpsia/metabolismo , Gravidez , Trofoblastos/metabolismo , Proteína Desacopladora 2/genética , Proteínas rho de Ligação ao GTP/genética
7.
Clin Exp Pharmacol Physiol ; 49(12): 1352-1360, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36106766

RESUMO

Hyperglycaemia is known to be associated with unfavourable outcomes in subarachnoid haemorrhage (SAH), but the pathogenic mechanism is unclear, and there is also a lack of effective therapeutic drugs in clinical practice. Phosphorylation of GSK3ß at serine 9 can inhibit its activity to further worsen SAH. The aim of the present study was to evaluate the protective effect and the potential mechanism of the GSK3ß inhibitor TDZD8 on brain injury in a hyperglycaemic SAH rat model. Hyperglycaemia was induced by intraperitoneal injection of streptozocin for 3 days. The SAH model was established by injecting fresh autologous femoral artery blood into the prechiasmatic cistern. p-GSK3ß (Ser9) expression was induced by intraperitoneal injection of TDZD8 (30 min post-SAH). The expression levels of GSK3ß, p-GSK3ß, SOD1/2, caspase 3, Bax and Bcl-2 were detected by western blot analysis. Terminal deoxynucleotidyl transferase dUTP nick end-labelling (TUNEL) staining was used to detect neuronal apoptosis of basal temporal lobe. Neurological scores were calculated to determine behavioural recovery. Neuronal survival was detected by Nissl staining. Hyperglycaemia significantly decreased p-GSK3ß expression, further exacerbated neurobehavioural deficits and increased oxidative stress and neuronal apoptosis in the brain after SAH compared to normal glycaemic SAH rats and hyperglycaemic rats. In addition, hyperglycaemic SAH rats had obvious oxidative stress and apoptosis. However, TDZD8 effectively decreased cleaved caspase 3 expression and TUNEL-positive cells and increased the Bcl2/Bax ratio, expression of SOD1/2 and activity of superoxide dismutase (SOD) enzyme compared with hyperglycaemic SAH rats. The GSK3ß inhibitor TDZD8 has therapeutic potential for hyperglycaemic SAH. The neuroprotective effect of TDZD8 appears to be mediated through its antioxidative and antiapoptotic activity.


Assuntos
Lesões Encefálicas , Hiperglicemia , Hemorragia Subaracnóidea , Animais , Ratos , Hemorragia Subaracnóidea/complicações , Caspase 3/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Espécies Reativas de Oxigênio , Proteína X Associada a bcl-2/metabolismo , Hiperglicemia/patologia , Superóxido Dismutase-1/metabolismo , Superóxido Dismutase-1/farmacologia , Superóxido Dismutase-1/uso terapêutico , Ratos Sprague-Dawley , Lesões Encefálicas/tratamento farmacológico , Apoptose , Encéfalo/metabolismo
8.
BMC Pediatr ; 22(1): 11, 2022 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-34980074

RESUMO

BACKGROUND: The prevalence of autism spectrum disorder (ASD) has increased rapidly in recent years. Environmental factors may play an important role in the pathogenesis of ASD. These factors may include socioeconomic factors, nutritional factors, heavy metal exposure, air pollution, etc. Our aim is to analyze possible environmental factors associated with the severity of ASD. METHODS: All participating children were divided into two groups (mild and moderate/severe) according to the severity of their symptoms, as determined by their Childhood Autism Rating Scale (CARS) scores. The socioeconomic, demographic factors and the nutritional factors that may affect the severity of ASD were included in the logistic regression to analyze whether they were predictors that affected the severity of ASD. RESULTS: Logistic regression showed that caregivers(P = 0.042), maternal education (P = 0.030), gastrointestinal problems (P = 0.041) and a high serum concentration of lead (P = 0.003) were statistically significantly associated with ASD severity. CONCLUSION: Many environmental factors affect the severity of ASD. We concluded that non-parental caregivers, low maternal education, gastrointestinal problems and high blood lead level maybe predictors that affected the severity of ASD in northeast China.


Assuntos
Transtorno do Espectro Autista , Gastroenteropatias , Transtorno do Espectro Autista/complicações , Transtorno do Espectro Autista/etiologia , Cuidadores , Estudos de Casos e Controles , Criança , Gastroenteropatias/complicações , Humanos , Chumbo
9.
Gut ; 69(3): 513-522, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31900289

RESUMO

OBJECTIVE: Pre-eclampsia (PE) is one of the malignant metabolic diseases that complicate pregnancy. Gut dysbiosis has been identified for causing metabolic diseases, but the role of gut microbiome in the pathogenesis of PE remains unknown. DESIGN: We performed a case-control study to compare the faecal microbiome of PE and normotensive pregnant women by 16S ribosomal RNA (rRNA) sequencing. To address the causative relationship between gut dysbiosis and PE, we used faecal microbiota transplantation (FMT) in an antibiotic-treated mouse model. Finally, we determined the microbiome translocation and immune responses in human and mouse placental samples by 16S rRNA sequencing, quantitative PCR and in situ hybridisation. RESULTS: Patients with PE showed reduced bacterial diversity with obvious dysbiosis. Opportunistic pathogens, particularly Fusobacterium and Veillonella, were enriched, whereas beneficial bacteria, including Faecalibacterium and Akkermansia, were markedly depleted in the PE group. The abundances of these discriminative bacteria were correlated with blood pressure (BP), proteinuria, aminotransferase and creatinine levels. On successful colonisation, the gut microbiome from patients with PE triggered a dramatic, increased pregestational BP of recipient mice, which further increased after gestation. In addition, the PE-transplanted group showed increased proteinuria, embryonic resorption and lower fetal and placental weights. Their T regulatory/helper-17 balance in the small intestine and spleen was disturbed with more severe intestinal leakage. In the placenta of both patients with PE and PE-FMT mice, the total bacteria, Fusobacterium, and inflammatory cytokine levels were significantly increased. CONCLUSIONS: This study suggests that the gut microbiome of patients with PE is dysbiotic and contributes to disease pathogenesis.


Assuntos
Translocação Bacteriana , Disbiose/complicações , Microbioma Gastrointestinal , Placenta/imunologia , Placenta/microbiologia , Pré-Eclâmpsia/microbiologia , Animais , Pressão Sanguínea , Contagem de Linfócito CD4 , Estudos de Casos e Controles , Quimiocinas/genética , Creatinina/sangue , Citocinas/genética , Modelos Animais de Doenças , Disbiose/fisiopatologia , Faecalibacterium , Fezes/microbiologia , Feminino , Reabsorção do Feto/microbiologia , Fusobactérias , Humanos , Intestino Delgado/imunologia , Camundongos , Placenta/metabolismo , Pré-Eclâmpsia/fisiopatologia , Gravidez , Proteinúria/urina , RNA Mensageiro/metabolismo , Linfócitos T Reguladores , Células Th17 , Veillonella
10.
Circulation ; 139(9): 1185-1198, 2019 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-30586715

RESUMO

BACKGROUND: Inflammatory response after myocardial infarction (MI) is essential for cardiac healing, whereas excessive and prolonged inflammation extends the infarction and promotes adverse cardiac remodeling. Understanding the mechanistic insight of these tightly controlled inflammatory processes has a significant impact on post-MI recovery and therapy. Here, we uncover the critical role of small GTPase RhoE in post-MI recovery and its clinical implication. METHODS: Three genetic mouse lines are used: global RhoE knockout, cardiomyocyte-specific RhoE heterozygous, and cardiomyocyte-specific RhoE overexpression mice. A set of molecular signaling experiments, including bimolecular fluorescence complementation, immunoprecipitation, electrophoretic mobility shift assay, and mRNA microarray analysis, were conducted. Permanent ligation of the left anterior descending artery was performed, followed by the assessments of cardiac function, inflammation, and survival in the first week after MI. Finally, we examined the correlation of the expression levels of RhoE in MI patient heart and patient prognosis. RESULTS: RhoE deficiency turns on a group of proinflammatory gene expressions in mouse heart. Mice with cardiomyocyte-specific haploinsufficiency exhibit excessive inflammatory response with deleterious cardiac function after MI. A profound increase in nuclear factor-κB activity is detected in the mutant heart and the isolated cardiomyocytes. We further find that the expression of RhoE is upregulated in response to MI. Mechanistically, RhoE interacts with p65 and p50 individually in cytosol and blocks their nuclear translocation. RhoE also occupies the dimerization domain of p65 and subsequently disrupts the heterodimerization between p65 and p50. Cardiac RhoE overexpression inhibits nuclear factor-κB activity, restrains post-MI inflammation, and improves cardiac function and survival. Consistently, we find that the expression level of RhoE is elevated in the heart of patients with MI and that the patients with a higher expression level of RhoE exhibit a better prognosis in cardiac function recovery. CONCLUSIONS: The study uncovers RhoE as a new fine-tuning factor modulating MI-induced inflammation and promoting injured heart recovery. RhoE may serve as a new potential biomarker for the assessment of MI patient prognosis. Manipulation of RhoE could be as a potential therapeutic approach for MI and other inflammatory diseases.


Assuntos
Regulação da Expressão Gênica , Infarto do Miocárdio/metabolismo , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Transdução de Sinais , Proteínas rho de Ligação ao GTP/metabolismo , Animais , Perfilação da Expressão Gênica , Humanos , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Camundongos , Camundongos Knockout , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Miocárdio/patologia , Miócitos Cardíacos/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas rho de Ligação ao GTP/genética
11.
Reproduction ; 159(2): 171-180, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31786538

RESUMO

Small extracellular vesicles (sEVs) are important mediators of cell-to-cell communication involved in the successful establishment of a pregnancy. Human decidual stromal cells play a key role in regulating trophoblast invasion. Nevertheless, the regulatory functions of decidual stromal cells-derived sEVs in human trophoblast cells are still unclear. In this study, primary human decidual stromal cells were isolated, and immortalized human endometrial stromal cell line (HESCs) were decidualized into human decidual stromal cells (HDSCs) using hormonal cocktail containing medroxy progesterone 17-acetate (MPA), estrogen and cAMP analog. HDSC-sEVs were isolated from both primary human decidual stromal cells and immortal HDSCs, respectively, and identified by transmission electron microscopy and western blotting. EV uptake assay indicated that HDSC-sEVs could be uptaken by trophoblast cells. HDSC-sEVs could increase the invasiveness and the expression level of N-cadherin of trophoblast cells with elevated phosphorylation of SMAD2 and SMAD3 in the cells. Silencing of N-cadherin could block cell invasion induced by HDSC-sEVs, while knockdown of SMAD2 and SMAD3 could inhibit the upregulation of N-cadherin in trophoblast cells. Taken together, our results suggested a regulatory effect of HDSC-sEVs in the invasion of trophoblast cells, and HDSC-sEVs may be important mediators of trophoblasts during embryo implantation and placentation.

12.
Zhongguo Dang Dai Er Ke Za Zhi ; 22(11): 1178-1182, 2020 Nov.
Artigo em Zh | MEDLINE | ID: mdl-33172551

RESUMO

OBJECTIVE: To study the intelligence structure and clinical features of children with attention deficit hyperactivity disorder (ADHD) and specific learning disorder (SLD). METHODS: A retrospective analysis was performed on 88 school-age children with ADHD. According to the presence or absence of SLD, they were divided into two groups: simple ADHD group with 45 children and ADHD+SLD group with 43 children. Intelligence structure and clinical features were compared between the two groups. RESULTS: Compared with the simple ADHD group, the ADHD+SLD group had significantly lower verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ), and full intelligence quotient (FIQ) (P<0.05), significantly lower scores of VIQ factors (including information, similarities, arithmetic, and recitation) (P<0.05), and significantly lower scores of PIQ factors (including picture completion, picture arrangement, block design, and object assembly) (P<0.05). The development of SLD was negatively correlated with FIQ, VIQ, and PIQ. It was also negatively correlated with the scores of intelligence structure factors (including information, similarities, arithmetic, recitation, picture completion, picture arrangement, block design, and object assembly) (P<0.05). CONCLUSIONS: Children with ADHD and SLD have poorer FIQ, VIQ, and PIQ than those with ADHD alone, which mainly manifests as the weak abilities of most intelligence structure factors. It is necessary to pay attention to the management and intervention of SLD in school-age children with ADHD.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Transtorno de Aprendizagem Específico , Criança , Humanos , Inteligência , Estudos Retrospectivos , Instituições Acadêmicas
13.
Proc Natl Acad Sci U S A ; 113(51): E8267-E8276, 2016 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-27930333

RESUMO

TET-family dioxygenases catalyze conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) and oxidized methylcytosines in DNA. Here, we show that mouse embryonic stem cells (mESCs), either lacking Tet3 alone or with triple deficiency of Tet1/2/3, displayed impaired adoption of neural cell fate and concomitantly skewed toward cardiac mesodermal fate. Conversely, ectopic expression of Tet3 enhanced neural differentiation and limited cardiac mesoderm specification. Genome-wide analyses showed that Tet3 mediates cell-fate decisions by inhibiting Wnt signaling, partly through promoter demethylation and transcriptional activation of the Wnt inhibitor secreted frizzled-related protein 4 (Sfrp4). Tet1/2/3-deficient embryos (embryonic day 8.0-8.5) showed hyperactivated Wnt signaling, as well as aberrant differentiation of bipotent neuromesodermal progenitors (NMPs) into mesoderm at the expense of neuroectoderm. Our data demonstrate a key role for TET proteins in modulating Wnt signaling and establishing the proper balance between neural and mesodermal cell fate determination in mouse embryos and ESCs.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Mesoderma/embriologia , Proteínas Proto-Oncogênicas/metabolismo , Via de Sinalização Wnt , 5-Metilcitosina/análogos & derivados , 5-Metilcitosina/química , Animais , Diferenciação Celular , Linhagem da Célula , Metilação de DNA , Dioxigenases , Células-Tronco Embrionárias/citologia , Epigênese Genética , Estudo de Associação Genômica Ampla , Camundongos , Camundongos Knockout , Miocárdio/metabolismo , Placa Neural/embriologia
14.
Biochim Biophys Acta Mol Cell Res ; 1864(4): 697-707, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28130125

RESUMO

Skeletal muscle cell proliferation and differentiation are tightly regulated. Epigenetic regulation is a major component of the regulatory mechanism governing these processes. Histone modification is part of the epigenetic code used for transcriptional regulation of chromatin through the establishment of an active or repressive state for genes involved in myogenesis in a temporal manner. Here, we uncovered the function of SET domain containing 2 (Setd2), an essential histone 3 lysine 36 trimethyltransferase, in regulating the proliferation and differentiation of myoblasts. Setd2 was silenced in the skeletal muscle myoblast cell line, C2C12, using the CRISPR/CAS9 system. The mutant cells exhibited defect in myotube formation. The myotube formation marker, myosin heavy chain (MHC), was downregulated earlier in Setd2 silenced cells compared to wild-type myoblasts during differentiation. The deficiency in Setd2 also resulted in repression of Myogenin (MyoG) expression, a key myogenic regulator during differentiation. In addition to the myoblast differentiation defect, decreased proliferation rate with significantly reduced levels of histone 3 phosphorylation, indicative of cell proliferation defect, were observed in the Setd2 silenced cells; suggesting an impaired proliferation phenotype. Furthermore, compromised G1/S- and G2/M-phase transition and decreased expression levels of major regulators of cell cycle G1/S checkpoints, cyclin D1, CDK4, CDK6, and cyclin E2 were detected in Setd2 silenced cells. Consistent with the cell cycle arrested phenotype, cyclin-dependent kinase inhibitor p21 was upregulated in Setd2 silenced cells. Together, this study demonstrates an essential role of Setd2 in myoblast proliferation and differentiation, and uncovers Setd2-mediated molecular mechanism through regulating MyoG and p21.


Assuntos
Inibidor de Quinase Dependente de Ciclina p21/genética , Histona-Lisina N-Metiltransferase/genética , Histonas/genética , Fibras Musculares Esqueléticas/metabolismo , Mioblastos/metabolismo , Miogenina/genética , Animais , Sequência de Bases , Sistemas CRISPR-Cas , Pontos de Checagem do Ciclo Celular , Diferenciação Celular , Linhagem Celular , Proliferação de Células , Cromatina/química , Cromatina/metabolismo , Ciclina D1/genética , Ciclina D1/metabolismo , Quinase 4 Dependente de Ciclina/genética , Quinase 4 Dependente de Ciclina/metabolismo , Quinase 6 Dependente de Ciclina/genética , Quinase 6 Dependente de Ciclina/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Ciclinas/genética , Ciclinas/metabolismo , Edição de Genes , Inativação Gênica , Histona-Lisina N-Metiltransferase/deficiência , Histonas/metabolismo , Camundongos , Fibras Musculares Esqueléticas/citologia , Mioblastos/citologia , Miogenina/metabolismo , Cadeias Pesadas de Miosina/genética , Cadeias Pesadas de Miosina/metabolismo , Fosforilação
15.
Zhongguo Dang Dai Er Ke Za Zhi ; 20(11): 974-978, 2018 Nov.
Artigo em Zh | MEDLINE | ID: mdl-30477634

RESUMO

The etiology and pathogenesis of autism spectrum disorder (ASD) are not yet clear. Studies have shown that there are many neurotransmitter abnormalities in children with ASD, mainly involving in glutamate, γ-aminobutyric acid (GABA), dopamine, 5-HT and oxytocin. The imbalance of excitatory glutamatergic neurotransmitters and inhibitory GABAergic neurotransmitters is closely related to the pathogenesis of ASD. Both animal model studies and clinical studies on ASD suggest that GABA signaling pathway may play an important role in the pathogenesis of ASD. This article reviews the research on the association between GABA signaling pathway and the pathogenesis of ASD to further explore the pathogenesis of ASD and provide theoretical basis for the treatment of ASD.


Assuntos
Transtorno do Espectro Autista , Animais , Modelos Animais de Doenças , Ácido Glutâmico , Humanos , Transdução de Sinais , Ácido gama-Aminobutírico
16.
Bioinformatics ; 32(17): i511-i519, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27587669

RESUMO

MOTIVATION: 5-methylcytosine (5mC) is a widely studied epigenetic modification of DNA. The ten-eleven translocation (TET) dioxygenases oxidize 5mC into oxidized methylcytosines (oxi-mCs): 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC). DNA methylation modifications have multiple functions. For example, 5mC is shown to be associated with diseases and oxi-mC species are reported to have a role in active DNA demethylation through 5mC oxidation and DNA repair, among others, but the detailed mechanisms are poorly understood. Bisulphite sequencing and its various derivatives can be used to gain information about all methylation modifications at single nucleotide resolution. Analysis of bisulphite based sequencing data is complicated due to the convoluted read-outs and experiment-specific variation in biochemistry. Moreover, statistical analysis is often complicated by various confounding effects. How to analyse 5mC and oxi-mC data sets with arbitrary and complex experimental designs is an open and important problem. RESULTS: We propose the first method to quantify oxi-mC species with arbitrary covariate structures from bisulphite based sequencing data. Our probabilistic modeling framework combines a previously proposed hierarchical generative model for oxi-mC-seq data and a general linear model component to account for confounding effects. We show that our method provides accurate methylation level estimates and accurate detection of differential methylation when compared with existing methods. Analysis of novel and published data gave insights into to the demethylation of the forkhead box P3 (Foxp3) locus during the induced T regulatory cell differentiation. We also demonstrate how our covariate model accurately predicts methylation levels of the Foxp3 locus. Collectively, LuxGLM method improves the analysis of DNA methylation modifications, particularly for oxi-mC species. AVAILABILITY AND IMPLEMENTATION: An implementation of the proposed method is available under MIT license at https://github.org/tare/LuxGLM/ CONTACT: taijo@simonsfoundation.org or harri.lahdesmaki@aalto.fi SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Metilação de DNA , 5-Metilcitosina , Citosina , DNA , Reparo do DNA , Proteínas de Ligação a DNA , Fatores de Transcrição Forkhead , Humanos , Oxirredução , Projetos de Pesquisa , Análise de Sequência de DNA
17.
Circ Res ; 116(1): e1-e10, 2015 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-25348166

RESUMO

RATIONALE: Rnd3, a small Rho GTPase, is involved in the regulation of cell actin cytoskeleton dynamics, cell migration, and proliferation. The biological function of Rnd3 in the heart remains unexplored. OBJECTIVE: To define the functional role of the Rnd3 gene in the animal heart and investigate the associated molecular mechanism. METHODS AND RESULTS: By loss-of-function approaches, we discovered that Rnd3 is involved in calcium regulation in cardiomyocytes. Rnd3-null mice died at the embryonic stage with fetal arrhythmias. The deletion of Rnd3 resulted in severe Ca(2+) leakage through destabilized ryanodine receptor type 2 Ca(2+) release channels. We further found that downregulation of Rnd3 attenuated ß2-adrenergic receptor lysosomal targeting and ubiquitination, which in turn resulted in the elevation of ß2-adrenergic receptor protein levels leading to the hyperactivation of protein kinase A (PKA) signaling. The PKA activation destabilized ryanodine receptor type 2 channels. This irregular spontaneous Ca(2+) release can be curtailed by PKA inhibitor treatment. Increases in the PKA activity along with elevated cAMP levels were detected in Rnd3-null embryos, in neonatal rat cardiomyocytes, and noncardiac cell lines with Rnd3 knockdown, suggesting a general mechanism for Rnd3-mediated PKA signaling activation. ß2-Adrenergic receptor blocker treatment reduced arrhythmia and improved cardiac function. CONCLUSIONS: Rnd3 is a novel factor involved in intracellular Ca(2+) homeostasis regulation in the heart. Deficiency of the protein induces ryanodine receptor type 2 dysfunction by a mechanism that attenuates Rnd3-mediated ß2-adrenergic receptor ubiquitination, which leads to the activation of PKA signaling. Increased PKA signaling in turn promotes ryanodine receptor type 2 hyperphosphorylation, which contributes to arrhythmogenesis and heart failure.


Assuntos
Cálcio/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/biossíntese , Deleção de Genes , Miócitos Cardíacos/metabolismo , Proteínas rho de Ligação ao GTP/deficiência , Proteínas rho de Ligação ao GTP/genética , Animais , Animais Recém-Nascidos , Células Cultivadas , Feminino , Coração/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ratos , Transdução de Sinais/fisiologia , Regulação para Cima/fisiologia
18.
Nutr Neurosci ; 20(5): 284-290, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26783092

RESUMO

OBJECTIVE: High prevalence of vitamin D deficiency was previously reported in children with Autism Spectrum Disorder (ASD), but little is known about the efficacy of vitamin D3 treatment in ASD, although data from pilot studies seem promising. We hypothesized that serum vitamin D levels are reduced in ASD and correlate with the severity of disease. Also, we hypothesized that vitamin D3 treatment may be beneficial for a considerable portion of children with ASD. METHODS: In total, 215 children with ASD and 285 healthy control children were recruited in our study. Thirty seven of 215 ASD children received vitamin D3 treatment. The Autism Behaviour Checklist (ABC) and the Childhood Autism Rating Scale (CARS) were used to assess autism symptoms. High-performance liquid chromatography was used to assess the serum 25-hydroxyvitamin D [25(OH) D] level. Evaluations of ABC, CARS, and serum 25(OH) D levels were performed before and after 3 months of treatment. RESULTS: Serum levels of 25(OH) D were significantly lower in ASD children than typically developing children. Levels of serum 25(OH) D were negatively correlated with ABC total scores and language subscale scores. After vitamin D3 supplementation, symptom scores were significantly reduced on the CARS and ABC. In addition, the data also suggest that treatment effects were more pronounced in younger children with ASD. CONCLUSION: Vitamin D deficiency might contribute to the aetiology of ASD. Supplementation of vitamin D3, which is a safe and cost-effective form of treatment, may significantly improve the outcome of some children with ASD, especially younger children (identifier ChiCTR-CCC-13004498). CLINICAL TRIAL REGISTRATION: The trial 'Association of Polymorphisms of Vitamin D Metabolism-Related Genes With Autism and the Treatment of Autism with Vitamin D' has been registered at www.chictr.org/cn/proj/show.aspx? proj=6135 (identifier ChiCTR-CCC-13004498).


Assuntos
Transtorno do Espectro Autista/tratamento farmacológico , Colecalciferol/uso terapêutico , Transtorno do Espectro Autista/sangue , Transtorno do Espectro Autista/etiologia , Criança , Comportamento Infantil/efeitos dos fármacos , Pré-Escolar , Suplementos Nutricionais , Feminino , Humanos , Masculino , Vitamina D/análogos & derivados , Vitamina D/sangue , Deficiência de Vitamina D/complicações
19.
Proc Natl Acad Sci U S A ; 111(32): E3306-15, 2014 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-25071199

RESUMO

The discovery of Ten Eleven Translocation proteins, enzymes that oxidize 5-methylcytosine (5mC) in DNA, has revealed novel mechanisms for the regulation of DNA methylation. We have mapped 5-hydroxymethylcytosine (5hmC) at different stages of T-cell development in the thymus and T-cell differentiation in the periphery. We show that 5hmC is enriched in the gene body of highly expressed genes at all developmental stages and that its presence correlates positively with gene expression. Further emphasizing the connection with gene expression, we find that 5hmC is enriched in active thymus-specific enhancers and that genes encoding key transcriptional regulators display high intragenic 5hmC levels in precursor cells at those developmental stages where they exert a positive effect. Our data constitute a valuable resource that will facilitate detailed analysis of the role of 5hmC in T-cell development and differentiation.


Assuntos
Citosina/análogos & derivados , Linfócitos T/citologia , Linfócitos T/metabolismo , 5-Metilcitosina/análogos & derivados , Animais , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Linhagem da Célula/genética , Linhagem da Célula/fisiologia , Citosina/metabolismo , Metilação de DNA , Proteínas de Ligação a DNA/metabolismo , Elementos Facilitadores Genéticos , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Proto-Oncogênicas/metabolismo , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/metabolismo
20.
Tumour Biol ; 2016 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-27747588

RESUMO

Transient receptor potential vanilloid 6 (TRPV6) has been shown to promote caner proliferation in several solid tumors, leading to unfavorable clinical outcomes. Our study aimed to elucidate the clinical significance of TRPV6 in patients with early-stage cervical squamous cell carcinoma (CSCC). The mRNA expression of TRPV6 was measured in 12 paired early-stage CSCC specimens and six cervical carcinoma cell lines using quantitative real-time PCR (qRT-PCR). Western blotting and immunohistochemistry (IHC) were employed to examine the protein expression level of TRPV6 in four paired specimens, 175 paraffin-embedded early-stage CSCC specimens, and 50 normal cervical tissues (NCTs), respectively. Statistical analyses were performed to evaluate the clinical significance of TRPV6 expression. The expressions of TRPV6 mRNA and protein were both significantly downregulated in early-stage CSCC tissues and cervical cancer cell lines. IHC analyses revealed that TRPV6 was downregulated in 136 (77.7 %) of 175 early-stage CSCC specimens. Moreover, TRPV6 expression in early-stage CSCC was significantly correlated with the tumor stage (P < 0.001), tumor growth type (P < 0.001), tumor size (P = 0.008), and differentiation grade (P = 0.003). The early-stage CSCC patients with a low TRPV6 expression level had a short progress-free survival (PFS) and overall survival (OS) duration. Univariate and multivariate analyses identified TRPV6 as an independent prognostic factor for early-stage CSCC patients' survival. We demonstrated that TRPV6 was downregulated in CSCC, which was correlated with unfavorable survival outcomes of early-stage CSCC patients. TRPV6 may be used as a novel prognostic marker for early-stage CSCC.

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