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1.
Genes Dev ; 35(3-4): 234-249, 2021 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33446570

RESUMEN

The physiological functions of many vital tissues and organs continue to mature after birth, but the genetic mechanisms governing this postnatal maturation remain an unsolved mystery. Human pancreatic ß cells produce and secrete insulin in response to physiological cues like glucose, and these hallmark functions improve in the years after birth. This coincides with expression of the transcription factors SIX2 and SIX3, whose functions in native human ß cells remain unknown. Here, we show that shRNA-mediated SIX2 or SIX3 suppression in human pancreatic adult islets impairs insulin secretion. However, transcriptome studies revealed that SIX2 and SIX3 regulate distinct targets. Loss of SIX2 markedly impaired expression of genes governing ß-cell insulin processing and output, glucose sensing, and electrophysiology, while SIX3 loss led to inappropriate expression of genes normally expressed in fetal ß cells, adult α cells, and other non-ß cells. Chromatin accessibility studies identified genes directly regulated by SIX2. Moreover, ß cells from diabetic humans with impaired insulin secretion also had reduced SIX2 transcript levels. Revealing how SIX2 and SIX3 govern functional maturation and maintain developmental fate in native human ß cells should advance ß-cell replacement and other therapeutic strategies for diabetes.


Asunto(s)
Diferenciación Celular/genética , Proteínas del Ojo/metabolismo , Regulación de la Expresión Génica/genética , Proteínas de Homeodominio/metabolismo , Células Secretoras de Insulina/citología , Proteínas del Tejido Nervioso/metabolismo , Diabetes Mellitus Tipo 2/fisiopatología , Humanos , Secreción de Insulina/genética , ARN Interferente Pequeño/metabolismo , Transcriptoma , Proteína Homeobox SIX3
2.
BMC Palliat Care ; 23(1): 59, 2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-38418964

RESUMEN

BACKGROUND: There is currently a high demand for bereavement support coupled with inconclusive findings as to the efficacy of existing approaches. Acceptance and Commitment Therapy (ACT) aims to improve human functioning and has shown efficacy across a wide range of conditions. ACT may be a promising means of supporting bereaved people, yet evidence on the use of ACT for bereavement support is lacking. The aim of this study is to explore how ACT is currently used for bereavement support and practitioner perspectives of how it helps following bereavement. METHODS: Semi-structured interviews were conducted online via MS Teams with practitioners experienced in using ACT for bereavement support. Data were analysed thematically guided by a framework approach. RESULTS: Nine participants were recruited. Three themes were identified: (i) creating psychological space around grief; (ii) using psychological space for value-directed action in the midst of grieving, and (iii) adapting ACT for bereavement support. Practitioners indicated that ACT improves clients' relationship with distressing internal experiences. Metaphors and mindfulness techniques were used to encourage acceptance of grief responses, taking perspective on distressing thoughts and images, and contact with the present moment. Better relationships with distressing experiences were regarded as less psychologically taxing, improving coping and well-being, while providing the psychological space to engage in value-directed action. Values exploration, sometimes using metaphors and exercises, was seen as supporting the bereaved person to rediscover a sense of purpose and engage in meaningful activities alongside their grief. Practitioners used ACT flexibly, integrating other interventions, and adapted ACT to the perceived sensitivities of bereaved people, and age-related and developmental factors. CONCLUSION: ACT is used to support people who have been bereaved to live effectively with the difficult thoughts and feelings associated with grieving and to enable them to gradually identify, reconnect with, and act in line with their values after loss.


Asunto(s)
Terapia de Aceptación y Compromiso , Aflicción , Humanos , Pesar , Habilidades de Afrontamiento , Investigación Cualitativa
3.
Development ; 147(6)2020 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-32108026

RESUMEN

Reliance on rodents for understanding pancreatic genetics, development and islet function could limit progress in developing interventions for human diseases such as diabetes mellitus. Similarities of pancreas morphology and function suggest that porcine and human pancreas developmental biology may have useful homologies. However, little is known about pig pancreas development. To fill this knowledge gap, we investigated fetal and neonatal pig pancreas at multiple, crucial developmental stages using modern experimental approaches. Purification of islet ß-, α- and δ-cells followed by transcriptome analysis (RNA-seq) and immunohistology identified cell- and stage-specific regulation, and revealed that pig and human islet cells share characteristic features that are not observed in mice. Morphometric analysis also revealed endocrine cell allocation and architectural similarities between pig and human islets. Our analysis unveiled scores of signaling pathways linked to native islet ß-cell functional maturation, including evidence of fetal α-cell GLP-1 production and signaling to ß-cells. Thus, the findings and resources detailed here show how pig pancreatic islet studies complement other systems for understanding the developmental programs that generate functional islet cells, and that are relevant to human pancreatic diseases.


Asunto(s)
Diferenciación Celular/genética , Células Secretoras de Insulina/fisiología , Islotes Pancreáticos/embriología , Islotes Pancreáticos/crecimiento & desarrollo , Porcinos , Animales , Animales Recién Nacidos , Células Cultivadas , Embrión de Mamíferos , Femenino , Feto/metabolismo , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Células Secretoras de Glucagón/citología , Células Secretoras de Glucagón/fisiología , Humanos , Islotes Pancreáticos/citología , Ratones , Organogénesis/genética , Embarazo , Porcinos/embriología , Porcinos/genética , Porcinos/crecimiento & desarrollo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transcriptoma
4.
Blood ; 138(26): 2838-2852, 2021 12 30.
Artículo en Inglés | MEDLINE | ID: mdl-34255814

RESUMEN

YTHDC1 has distinct functions as a nuclear N6-methyladenosine (m6A) reader in regulating RNA metabolism. Here we show that YTHDC1 is overexpressed in acute myeloid leukemia (AML) and that it is required for the proliferation and survival of human AML cells. Genetic deletion of Ythdc1 markedly blocks AML development and maintenance as well as self-renewal of leukemia stem cells (LSCs) in vivo in mice. We found that Ythdc1 is also required for normal hematopoiesis and hematopoietic stem and progenitor cell (HSPC) maintenance in vivo. Notably, Ythdc1 haploinsufficiency reduces self-renewal of LSCs but not HSPCs in vivo. YTHDC1 knockdown has a strong inhibitory effect on proliferation of primary AML cells. Mechanistically, YTHDC1 regulates leukemogenesis through MCM4, which is a critical regulator of DNA replication. Our study provides compelling evidence that shows an oncogenic role and a distinct mechanism of YTHDC1 in AML.


Asunto(s)
Regulación Leucémica de la Expresión Génica , Leucemia Mieloide Aguda/genética , Proteínas de Mantenimiento de Minicromosoma/genética , Proteínas del Tejido Nervioso/genética , Factores de Empalme de ARN/genética , Adenosina/análogos & derivados , Adenosina/genética , Animales , Carcinogénesis/genética , Línea Celular Tumoral , Replicación del ADN , Humanos , Ratones Transgénicos , Componente 4 del Complejo de Mantenimiento de Minicromosoma/genética , Regulación hacia Arriba
5.
Nucleic Acids Res ; 49(21): 12433-12444, 2021 12 02.
Artículo en Inglés | MEDLINE | ID: mdl-34850124

RESUMEN

Streptococcus pyogenes Cas9 (SpCas9), a programmable RNA-guided DNA endonuclease, has been widely repurposed for biological and medical applications. Critical interactions between SpCas9 and DNA confer the high specificity of the enzyme in genome engineering. Here, we unveil that an essential SpCas9-DNA interaction located beyond the protospacer adjacent motif (PAM) is realized through electrostatic forces between four positively charged lysines among SpCas9 residues 1151-1156 and the negatively charged DNA backbone. Modulating this interaction by substituting lysines with amino acids that have distinct charges revealed a strong dependence of DNA target binding and cleavage activities of SpCas9 on the charge. Moreover, the SpCas9 mutants show markedly distinguishable DNA interaction sites beyond the PAM compared with wild-type SpCas9. Functionally, this interaction governs DNA sampling and participates in protospacer DNA unwinding during DNA interrogation. Overall, a mechanistic and functional understanding of this vital interaction explains how SpCas9 carries out efficient DNA interrogation.


Asunto(s)
Secuencias de Aminoácidos , Proteína 9 Asociada a CRISPR/metabolismo , ADN/metabolismo , Motivos de Nucleótidos , Streptococcus pyogenes/enzimología , Proteína 9 Asociada a CRISPR/química , Proteína 9 Asociada a CRISPR/genética , ADN/química , ADN/genética , División del ADN , Transferencia Resonante de Energía de Fluorescencia/métodos , Células HEK293 , Humanos , Mutación , Unión Proteica , Electricidad Estática , Streptococcus pyogenes/genética
6.
J Cell Mol Med ; 25(23): 10879-10891, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34716659

RESUMEN

N6 -methyladenosine (m6 A) is the most prevalent modification in mRNA and engages in multiple biological processes. Previous studies indicated that m6 A methyltransferase METTL3 ('writer') and demethylase FTO ('eraser') play critical roles in heart-related disease. However, in the heart, the function of m6 A 'reader', such as YTH (YT521-B homology) domain-containing proteins remains unclear. Here, we report that the defect in YTHDC1 but not other YTH family members contributes to dilated cardiomyopathy (DCM) in mice. Cardiac-specific conditional Ythdc1 knockout led to obvious left ventricular chamber enlargement and severe systolic dysfunction. YTHDC1 deficiency also resulted in the decrease of cardiomyocyte contractility and disordered sarcomere arrangement. By means of integrating multiple high-throughput sequence technologies, including m6 A-MeRIP, RIP-seq and mRNA-seq, we identified 42 transcripts as potential downstream targets of YTHDC1. Amongst them, we found that Titin mRNA was decorated with m6 A modification and depletion of YTHDC1 resulted in aberrant splicing of Titin. Our study suggests that Ythdc1 plays crucial role in regulating the normal contractile function and the development of DCM. These findings clarify the essential role of m6 A reader in cardiac biofunction and provide a novel potential target for the treatment of DCM.


Asunto(s)
Cardiomiopatía Dilatada/metabolismo , Metiltransferasas/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Proteínas Quinasas/metabolismo , Factores de Empalme de ARN/metabolismo , Adenosina/metabolismo , Animales , Conectina/metabolismo , Masculino , Ratones , Proteínas de Unión al ARN/metabolismo , Factores de Empalme Serina-Arginina/metabolismo
7.
Ecol Lett ; 23(5): 821-830, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32100414

RESUMEN

Grassland ecosystems account for more than 10% of the global CH4 sink in soils. A 4-year field experiment found that addition of P alone did not affect CH4 uptake and experimental addition of N alone significantly suppressed CH4 uptake, whereas concurrent N and P additions suppressed CH4 uptake to a lesser degree. A meta-analysis including 382 data points in global grasslands corroborated these findings. Global extrapolation with an empirical modelling approach estimated that contemporary N addition suppresses CH4 sink in global grassland by 11.4% and concurrent N and P deposition alleviates this suppression to 5.8%. The P alleviation of N-suppressed CH4 sink is primarily attributed to substrate competition, defined as the competition between ammonium and CH4 for the methane mono-oxygenase enzyme. The N and P impacts on CH4 uptake indicate that projected increases in N and P depositions might substantially affect CH4 uptake and alter the global CH4 cycle.


Asunto(s)
Metano , Nitrógeno , Ecosistema , Pradera , Fósforo , Suelo
8.
Development ; 144(20): 3744-3754, 2017 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-28893946

RESUMEN

The islets of Langerhans are endocrine organs characteristically dispersed throughout the pancreas. During development, endocrine progenitors delaminate, migrate radially and cluster to form islets. Despite the distinctive distribution of islets, spatially localized signals that control islet morphogenesis have not been discovered. Here, we identify a radial signaling axis that instructs developing islet cells to disperse throughout the pancreas. A screen of pancreatic extracellular signals identified factors that stimulated islet cell development. These included semaphorin 3a, a guidance cue in neural development without known functions in the pancreas. In the fetal pancreas, peripheral mesenchymal cells expressed Sema3a, while central nascent islet cells produced the semaphorin receptor neuropilin 2 (Nrp2). Nrp2 mutant islet cells developed in proper numbers, but had defects in migration and were unresponsive to purified Sema3a. Mutant Nrp2 islets aggregated centrally and failed to disperse radially. Thus, Sema3a-Nrp2 signaling along an unrecognized pancreatic developmental axis constitutes a chemoattractant system essential for generating the hallmark morphogenetic properties of pancreatic islets. Unexpectedly, Sema3a- and Nrp2-mediated control of islet morphogenesis is strikingly homologous to mechanisms that regulate radial neuronal migration and cortical lamination in the developing mammalian brain.


Asunto(s)
Islotes Pancreáticos/citología , Neuropilina-2/metabolismo , Semaforina-3A/metabolismo , Animales , Adhesión Celular , Movimiento Celular , Factores Quimiotácticos/química , Regulación del Desarrollo de la Expresión Génica , Humanos , Ligandos , Ratones , Ratones Noqueados , Morfogénesis , Mutación , Neuronas/metabolismo , Neuropilina-2/genética , Páncreas/citología , Semaforina-3A/genética , Transducción de Señal
9.
World J Microbiol Biotechnol ; 34(12): 179, 2018 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-30456633

RESUMEN

Botryosphaeria kuwatsukai is an important fungal pathogen affecting pear fruits. However, infection processes of this fungus are still unclear. This study seeks to develop the fungal transformation of B. kuwatsukai by Agrobacterium tumefaciens-mediated transformation (ATMT), assess the reliability of appropriate vectors and examine the infection processes in vitro using a GFP labeled strain of B. kuwatsukai. To establish a highly effective transformation system in B. kuwatsukai, binary vectors containing various lengths of H3 promoters and TEF promoters fused with GFP and hygromycin B resistance gene cassettes were constructed. These cassettes were integrated into the genomic DNA of B. kuwatsukai with high transformation frequency by the ATMT method. Transformants showed strong expression of GFP and hygromycin B resistance genes in cells. Furthermore, we investigated if native promoters are more suitable to govern marker genes than other general promoters used in other filamentous fungi. The results obtained herein demonstrate that the vectors constructed in this study can be utilized with high transformation rate. Microscopic examinations also reveal that fungal hyphae undergo morphological changes during the infection process resulting in biotrophic stage of infected host cells. Our results provide genetic insights to further explore the infection processes of B. kuwatsukai.


Asunto(s)
Agrobacterium tumefaciens/genética , Ascomicetos/efectos de los fármacos , Ascomicetos/genética , Higromicina B/farmacología , Regiones Promotoras Genéticas/genética , Pyrus/microbiología , Transformación Genética , Agrobacterium tumefaciens/metabolismo , Antibacterianos/farmacología , Ascomicetos/crecimiento & desarrollo , Ascomicetos/patogenicidad , ADN Bacteriano/genética , ADN de Hongos , Farmacorresistencia Bacteriana/genética , Regulación Bacteriana de la Expresión Génica/genética , Marcadores Genéticos , Vectores Genéticos , Enfermedades de las Plantas/prevención & control , Virulencia
10.
Nature ; 478(7369): 349-55, 2011 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-21993628

RESUMEN

Determining the signalling pathways that direct tissue expansion is a principal goal of regenerative biology. Vigorous pancreatic ß-cell replication in juvenile mice and humans declines with age, and elucidating the basis for this decay may reveal strategies for inducing ß-cell expansion, a long-sought goal for diabetes therapy. Here we show that platelet-derived growth factor receptor (Pdgfr) signalling controls age-dependent ß-cell proliferation in mouse and human pancreatic islets. With age, declining ß-cell Pdgfr levels were accompanied by reductions in ß-cell enhancer of zeste homologue 2 (Ezh2) levels and ß-cell replication. Conditional inactivation of the Pdgfra gene in ß-cells accelerated these changes, preventing mouse neonatal ß-cell expansion and adult ß-cell regeneration. Targeted human PDGFR-α activation in mouse ß-cells stimulated Erk1/2 phosphorylation, leading to Ezh2-dependent expansion of adult ß-cells. Adult human islets lack PDGF signalling competence, but exposure of juvenile human islets to PDGF-AA stimulated ß-cell proliferation. The discovery of a conserved pathway controlling age-dependent ß-cell proliferation indicates new strategies for ß-cell expansion.


Asunto(s)
Células Secretoras de Insulina/citología , Células Secretoras de Insulina/fisiología , Receptores del Factor de Crecimiento Derivado de Plaquetas/metabolismo , Transducción de Señal , Factores de Edad , Animales , Proliferación Celular , Células Cultivadas , Diabetes Mellitus Experimental/patología , Factores de Transcripción E2F/metabolismo , Proteína Potenciadora del Homólogo Zeste 2 , Femenino , Regulación Enzimológica de la Expresión Génica , Técnicas de Inactivación de Genes , N-Metiltransferasa de Histona-Lisina/genética , Humanos , Células Secretoras de Insulina/enzimología , Masculino , Ratones , Ratones Endogámicos C57BL , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Complejo Represivo Polycomb 2 , Proteína de Retinoblastoma/metabolismo
11.
PLoS Genet ; 10(10): e1004645, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25330008

RESUMEN

The regulatory logic underlying global transcriptional programs controlling development of visceral organs like the pancreas remains undiscovered. Here, we profiled gene expression in 12 purified populations of fetal and adult pancreatic epithelial cells representing crucial progenitor cell subsets, and their endocrine or exocrine progeny. Using probabilistic models to decode the general programs organizing gene expression, we identified co-expressed gene sets in cell subsets that revealed patterns and processes governing progenitor cell development, lineage specification, and endocrine cell maturation. Purification of Neurog3 mutant cells and module network analysis linked established regulators such as Neurog3 to unrecognized gene targets and roles in pancreas development. Iterative module network analysis nominated and prioritized transcriptional regulators, including diabetes risk genes. Functional validation of a subset of candidate regulators with corresponding mutant mice revealed that the transcription factors Etv1, Prdm16, Runx1t1 and Bcl11a are essential for pancreas development. Our integrated approach provides a unique framework for identifying regulatory genes and functional gene sets underlying pancreas development and associated diseases such as diabetes mellitus.


Asunto(s)
Separación Celular/métodos , Regulación del Desarrollo de la Expresión Génica , Páncreas/citología , Páncreas/embriología , Páncreas/crecimiento & desarrollo , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Genómica/métodos , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/fisiología , Ratones Mutantes , Ratones Transgénicos , Modelos Estadísticos , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Reproducibilidad de los Resultados , Factor de Transcripción SOX9/genética , Células Madre/citología , Células Madre/fisiología
12.
Genes Dev ; 23(8): 975-85, 2009 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-19390090

RESUMEN

Proliferation of pancreatic islet beta cells is an important mechanism for self-renewal and for adaptive islet expansion. Increased expression of the Ink4a/Arf locus, which encodes the cyclin-dependent kinase inhibitor p16(INK4a) and tumor suppressor p19(Arf), limits beta-cell regeneration in aging mice, but the basis of beta-cell Ink4a/Arf regulation is poorly understood. Here we show that Enhancer of zeste homolog 2 (Ezh2), a histone methyltransferase and component of a Polycomb group (PcG) protein complex, represses Ink4a/Arf in islet beta cells. Ezh2 levels decline in aging islet beta cells, and this attrition coincides with reduced histone H3 trimethylation at Ink4a/Arf, and increased levels of p16(INK4a) and p19(Arf). Conditional deletion of beta-cell Ezh2 in juvenile mice also reduced H3 trimethylation at the Ink4a/Arf locus, leading to precocious increases of p16(INK4a) and p19(Arf). These mutant mice had reduced beta-cell proliferation and mass, hypoinsulinemia, and mild diabetes, phenotypes rescued by germline deletion of Ink4a/Arf. beta-Cell destruction with streptozotocin in controls led to increased Ezh2 expression that accompanied adaptive beta-cell proliferation and re-establishment of beta-cell mass; in contrast, mutant mice treated similarly failed to regenerate beta cells, resulting in lethal diabetes. Our discovery of Ezh2-dependent beta-cell proliferation revealed unique epigenetic mechanisms underlying normal beta-cell expansion and beta-cell regenerative failure in diabetes pathogenesis.


Asunto(s)
Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Diabetes Mellitus/metabolismo , Regulación de la Expresión Génica , N-Metiltransferasa de Histona-Lisina/metabolismo , Células Secretoras de Insulina/metabolismo , Envejecimiento/metabolismo , Animales , Antibióticos Antineoplásicos/farmacología , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Proteína Potenciadora del Homólogo Zeste 2 , Femenino , Eliminación de Gen , Regulación de la Expresión Génica/efectos de los fármacos , Histonas/metabolismo , Humanos , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Complejo Represivo Polycomb 2 , Estreptozocina/farmacología
13.
Genet Mol Biol ; 40(3): 591-596, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28863211

RESUMEN

X-linked intellectual disability (XLID) has been associated with various genes. Diagnosis of XLID, especially for non-syndromic ones (NS-XLID), is often hampered by the heterogeneity of this disease. Here we report the case of a Chinese family in which three males suffer from intellectual disability (ID). The three patients shared the same phenotype: no typical clinical manifestation other than IQ score ≤ 70. For a genetic diagnosis for this family we carried out whole exome sequencing on the proband, and validated 16 variants of interest in the genomic DNA of all the family members. A missense mutation (c.710G > T), which mapped to exon 6 of the Rab GDP-Dissociation Inhibitor 1 (GDI1) gene, was found segregating with the ID phenotype, and this mutation changes the 237th position in the guanosine diphosphate dissociation inhibitor (GDI) protein from glycine to valine (p. Gly237Val). Through molecular dynamics simulations we found that this substitution results in a conformational change of GDI, possibly affecting the Rab-binding capacity of this protein. In conclusion, our study identified a novel GDI1 mutation that is possibly NS-XLID causative, and showed that whole exome sequencing provides advantages for detecting novel ID-associated variants and can greatly facilitate the genetic diagnosis of the disease.

14.
Diabetes ; 73(3): 448-460, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38064570

RESUMEN

Mutations in the gene encoding the transcription factor regulatory factor X-box binding 6 (RFX6) are associated with human diabetes. Within pancreatic islets, RFX6 expression is most abundant in islet α-cells, and α-cell RFX6 expression is altered in diabetes. However, the roles of RFX6 in regulating gene expression, glucagon output, and other crucial human adult α-cell functions are not yet understood. We developed a method for selective genetic targeting of human α-cells and assessed RFX6-dependent α-cell function. RFX6 suppression with RNA interference led to impaired α-cell exocytosis and dysregulated glucagon secretion in vitro and in vivo. By contrast, these phenotypes were not observed with RFX6 suppression across all islet cells. Transcriptomics in α-cells revealed RFX6-dependent expression of genes governing nutrient sensing, hormone processing, and secretion, with some of these exclusively expressed in human α-cells. Mapping of RFX6 DNA-binding sites in primary human islet cells identified a subset of direct RFX6 target genes. Together, these data unveil RFX6-dependent genetic targets and mechanisms crucial for regulating adult human α-cell function.


Asunto(s)
Diabetes Mellitus , Islotes Pancreáticos , Humanos , Glucagón/metabolismo , Factores de Transcripción del Factor Regulador X/genética , Factores de Transcripción del Factor Regulador X/metabolismo , Islotes Pancreáticos/metabolismo , Diabetes Mellitus/metabolismo , Expresión Génica , Insulina/metabolismo
15.
Nat Genet ; 30(4): 430-5, 2002 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11912494

RESUMEN

Pbx1 is a member of the TALE (three-amino acid loop extension) class of homeodomain transcription factors, which are components of hetero-oligomeric protein complexes thought to regulate developmental gene expression and to maintain differentiated cell states. In vitro studies have shown that Pbx1 regulates the activity of Ipf1 (also known as Pdx1), a ParaHox homeodomain transcription factor required for the development and function of the pancreas in mice and humans. To investigate in vivo roles of Pbx1 in pancreatic development and function, we examined pancreatic Pbx1 expression, and morphogenesis, cell differentiation and function in mice deficient for Pbx1. Pbx1-/- embryos had pancreatic hypoplasia and marked defects in exocrine and endocrine cell differentiation prior to death at embryonic day (E) 15 or E16. In these embryos, expression of Isl1 and Atoh5, essential regulators of pancreatic morphogenesis and differentiation, was severely reduced. Pbx1+/- adults had pancreatic islet malformations, impaired glucose tolerance and hypoinsulinemia. Thus, Pbx1 is essential for normal pancreatic development and function. Analysis of trans-heterozygous Pbx1+/- Ipf1+/- mice revealed in vivo genetic interactions between Pbx1 and Ipf1 that are essential for postnatal pancreatic function; these mice developed age-dependent overt diabetes mellitus, unlike Pbx1+/- or Ipf1+/- mice. Mutations affecting the Ipf1 protein may promote diabetes mellitus in mice and humans. This study suggests that perturbation of Pbx1 activity may also promote susceptibility to diabetes mellitus.


Asunto(s)
Proteínas de Unión al ADN/genética , Diabetes Mellitus/genética , Proteínas de Homeodominio , Páncreas/embriología , Páncreas/fisiología , Proteínas Proto-Oncogénicas/genética , Transactivadores/genética , Animales , Bromodesoxiuridina/metabolismo , Diferenciación Celular , Proteínas de Unión al ADN/fisiología , Predisposición Genética a la Enfermedad , Genotipo , Inmunohistoquímica , Islotes Pancreáticos/citología , Ratones , Ratones Transgénicos , Microscopía Confocal , Factor de Transcripción 1 de la Leucemia de Células Pre-B , Unión Proteica , Estructura Terciaria de Proteína , Proteínas Proto-Oncogénicas/fisiología , Recombinación Genética , Factores de Tiempo
16.
JCI Insight ; 8(24)2023 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-37943614

RESUMEN

HNF1A haploinsufficiency underlies the most common form of human monogenic diabetes (HNF1A-maturity onset diabetes of the young [HNF1A-MODY]), and hypomorphic HNF1A variants confer type 2 diabetes risk. But a lack of experimental systems for interrogating mature human islets has limited our understanding of how the transcription factor HNF1α regulates adult islet function. Here, we combined conditional genetic targeting in human islet cells, RNA-Seq, chromatin mapping with cleavage under targets and release using nuclease (CUT&RUN), and transplantation-based assays to determine HNF1α-regulated mechanisms in adult human pancreatic α and ß cells. Short hairpin RNA-mediated (shRNA-mediated) suppression of HNF1A in primary human pseudoislets led to blunted insulin output and dysregulated glucagon secretion after transplantation in mice, recapitulating phenotypes observed in patients with diabetes. These deficits corresponded with altered expression of genes encoding factors critical for hormone secretion, including calcium channel subunits, ATPase transporters, and extracellular matrix constituents. Additionally, HNF1A loss led to upregulation of transcriptional repressors, providing evidence for a mechanism of transcriptional derepression through HNF1α. CUT&RUN mapping of HNF1α DNA binding sites in primary human islets imputed a subset of HNF1α-regulated genes as direct targets. These data elucidate mechanistic links between HNF1A loss and diabetic phenotypes in mature human α and ß cells.


Asunto(s)
Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Animales , Humanos , Ratones , Diabetes Mellitus Tipo 2/metabolismo , Regulación de la Expresión Génica , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Páncreas/metabolismo
17.
Nature ; 443(7109): 345-9, 2006 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-16988714

RESUMEN

The growth and function of organs such as pancreatic islets adapt to meet physiological challenges and maintain metabolic balance, but the mechanisms controlling these facultative responses are unclear. Diabetes in patients treated with calcineurin inhibitors such as cyclosporin A indicates that calcineurin/nuclear factor of activated T-cells (NFAT) signalling might control adaptive islet responses, but the roles of this pathway in beta-cells in vivo are not understood. Here we show that mice with a beta-cell-specific deletion of the calcineurin phosphatase regulatory subunit, calcineurin b1 (Cnb1), develop age-dependent diabetes characterized by decreased beta-cell proliferation and mass, reduced pancreatic insulin content and hypoinsulinaemia. Moreover, beta-cells lacking Cnb1 have a reduced expression of established regulators of beta-cell proliferation. Conditional expression of active NFATc1 in Cnb1-deficient beta-cells rescues these defects and prevents diabetes. In normal adult beta-cells, conditional NFAT activation promotes the expression of cell-cycle regulators and increases beta-cell proliferation and mass, resulting in hyperinsulinaemia. Conditional NFAT activation also induces the expression of genes critical for beta-cell endocrine function, including all six genes mutated in hereditary forms of monogenic type 2 diabetes. Thus, calcineurin/NFAT signalling regulates multiple factors that control growth and hallmark beta-cell functions, revealing unique models for the pathogenesis and therapy of diabetes.


Asunto(s)
Calcineurina/metabolismo , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/metabolismo , Factores de Transcripción NFATC/metabolismo , Transducción de Señal , Envejecimiento , Animales , Proliferación Celular , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Hiperinsulinismo/genética , Hiperinsulinismo/metabolismo , Ratones , Ratones Noqueados , Factores de Transcripción NFATC/genética , Monoéster Fosfórico Hidrolasas/química , Monoéster Fosfórico Hidrolasas/genética , Monoéster Fosfórico Hidrolasas/metabolismo , Subunidades de Proteína/deficiencia , Subunidades de Proteína/genética , Transporte de Proteínas
18.
Front Psychol ; 13: 824198, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35572329

RESUMEN

In recent years, employment has become a growing problem for Chinese college students, who often face issues of slow employment and lazy employment. Guided by the framework of career construction theory, we explored how proactive personality strengthens career adaptability. A total of 423 Chinese college students effectively completed the online survey. The results showed a positive correlation between proactive personality, future work self salience, future time perspective, and career adaptability. Additionally, proactive personality can directly affect career adaptability through three indirect paths: the separate intermediary effect of future work self salience, future time perspective, and the continuous mediating role of future work self salience and future time perspective. The results indicate that proactive personality increases career adaptability through the mediating role of future work self salience and future time perspective. This study contributes to our understanding of the mechanisms underlying the relationship between proactive personality and career adaptability. Additionally, the findings have implications for the career development of college students.

19.
Cell Prolif ; 55(1): e13164, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34850470

RESUMEN

OBJECTIVES: Accumulating evidences show that the regulatory network of m6 A modification is essential for mammalian spermatogenesis. However, as an m6 A reader, the roles of YTHDF2 remain enigmatic due to the lack of a proper model. Here, we employed the germ cell conditional knockout mouse model and explored the function of YTHDF2 in spermatogenesis. MATERIALS AND METHODS: Ythdf2 germ cell conditional knockout mice were obtained by crossing Ythdf2-floxed mice with Vasa-Cre and Stra8-Cre mice. Haematoxylin and eosin (HE) staining, immunofluorescent staining and Western blotting were used for phenotyping. CASA, IVF and ICSI were applied for sperm function analysis. RNA-seq, YTHDF2-RIP-seq and quantitative real-time PCR were used to explore transcriptome changes and molecular mechanism analysis. RESULTS: Our results showed that YTHDF2 was highly expressed in spermatogenic cells. The germ cell conditional knockout males were sterile, and their sperm displayed malformation, impaired motility, and lost fertilization ability. During differentiated spermatogonia transiting to pachytene spermatocyte, most m6 A-modified YTHDF2 targets that were degraded in control germ cells persisted in pachytene spermatocytes of Ythdf2-vKO mice. These delayed mRNAs were mainly enriched in pathways related to the regulation of transcription, and disturbed the transcriptome of round spermatid and elongated spermatid subsequently. CONCLUSION: Our data demonstrate that YTHDF2 facilitates the timely turnover of phase-specific transcripts to ensure the proper progression of spermatogenesis, which highlights a critical role of YTHDF2 in spermatogenesis.


Asunto(s)
Adenosina/análogos & derivados , Proteínas de Unión al ARN/metabolismo , Espermatogénesis/genética , Adenosina/metabolismo , Animales , Fertilidad , Fertilización , Eliminación de Gen , Células Germinativas/metabolismo , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/genética , Espermatozoides/metabolismo , Espermatozoides/patología , Transcriptoma/genética
20.
Front Psychol ; 12: 815076, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35082735

RESUMEN

To assist Chinese high school students in improving their career readiness and tackling career decision-making difficulties, we designed a synchronous online career intervention based on the Cognitive Information Processing (CIP) theory during the Covid-19 pandemic. The online career intervention consisted of a series of career courses to develop high school students' knowledge and skills in career planning, career assessments for exploring their vocational interests and academic self-concept, and a database providing basic information about university majors. To evaluate the intervention's effectiveness, 957 10th grade students were recruited in the study, 601 participants (girls = 227, boys = 324) were randomly assigned to the experimental group (online career intervention), and 356 (girls = 159, boys = 197) participants were randomly assigned to the control group (no any career interventions). All participants completed a pre- and post-intervention assessment of their career maturity, vocational identity and career decision-making difficulties. Results indicated that the online intervention significantly increased high school students' career readiness and reduced their career decision-making difficulties. The practical implications of this research for online career interventions directed at Chinese high school students are also discussed.

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