Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Más filtros










Intervalo de año de publicación
2.
Int J Mol Sci ; 22(4)2021 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-33562813

RESUMEN

The conserved Blm10/PA200 proteins are proteasome activators. Previously, we identified PA200-enriched regions in the genome of SH-SY5Y neuroblastoma cells by chromatin immunoprecipitation (ChIP) and ChIP-seq analysis. We also found that selective mitochondrial inhibitors induced PA200 redistribution in the genome. Collectively, our data indicated that PA200 regulates cellular homeostasis at the transcriptional level. In the present study, our aim is to investigate the impact of stable PA200 depletion (shPA200) on the overall transcriptome of SH-SY5Y cells. RNA-seq data analysis reveals that the genetic ablation of PA200 leads to overall changes in the transcriptional landscape of SH-SY5Y neuroblastoma cells. PA200 activates and represses genes regulating metabolic processes, such as the glycolysis and mitochondrial function. Using metabolic assays in live cells, we showed that stable knockdown of PA200 does not change basal respiration. Spare respiratory capacity and proton leak however are slightly, yet significantly, reduced in PA200-deficient cells by 99.834% and 84.147%, respectively, compared to control. Glycolysis and glycolytic capacity show a 42.186% and 26.104% increase in shPA200 cells, respectively, compared to control. These data suggest a shift from oxidative phosphorylation to glycolysis especially when cells are exposed to oligomycin-induced stress. Furthermore, we observed a preserved long and compact tubular mitochondrial morphology after inhibition of ATP synthase by oligomycin, which might be associated with the glycolytic change of shPA200 cells. The present study also demonstrates that the proteolytic cleavage of Opa1 is affected, and that the level of OMA1 is significantly reduced in shPA200 cells upon oligomycin-induced mitochondrial insult. Together, these findings suggest a role for PA200 in the regulation of metabolic changes in response to selective inhibition of ATP synthase in an in vitro cellular model.


Asunto(s)
GTP Fosfohidrolasas/genética , Perfilación de la Expresión Génica/métodos , Neuroblastoma/genética , Proteínas Nucleares/genética , ARN Interferente Pequeño/farmacología , Línea Celular Tumoral , Inmunoprecipitación de Cromatina , Eliminación de Gen , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Redes Reguladoras de Genes , Glucólisis/efectos de los fármacos , Humanos , Mitocondrias/efectos de los fármacos , Mitocondrias/genética , Proteínas Nucleares/antagonistas & inhibidores , Oligomicinas/farmacología , Fosforilación Oxidativa/efectos de los fármacos , Análisis de Secuencia de ARN
3.
J Cell Mol Med ; 24(12): 6716-6730, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32368861

RESUMEN

The conserved Blm10/PA200 activators bind to the proteasome core and facilitate peptide and protein turnover. Blm10/PA200 proteins enhance proteasome peptidase activity and accelerate the degradation of unstructured proteasome substrates. Our knowledge about the exact role of PA200 in diseased cells, however, is still limited. Here, we show that stable knockdown of PA200 leads to a significantly elevated number of cells in S phase after treatment with the ATP synthase inhibitor, oligomycin. However, following exposure to the complex I inhibitor rotenone, more PA200-depleted cells were in sub-G1 and G2/M phases indicative of apoptosis. Chromatin immunoprecipitation (ChIP) and ChIP-seq data analysis of collected reads indicate PA200-enriched regions in the genome of SH-SY5Y. We found that PA200 protein peaks were in the vicinity of transcription start sites. Gene ontology annotation revealed that genes whose promoters were enriched upon anti-PA200 ChIP contribute to the regulation of crucial intracellular processes, including proliferation, protein modifications and metabolism. Selective mitochondrial inhibitors induced PA200 redistribution in the genome, leading to protein withdrawal from some gene promoters and binding to others. Collectively, the results support a model in which PA200 potentially regulates cellular homeostasis at the transcriptional level, in addition to its described role as an alternative activator of the proteasome.


Asunto(s)
Regulación Neoplásica de la Expresión Génica , Mitocondrias/metabolismo , Neuroblastoma/genética , Neuroblastoma/patología , Proteínas Nucleares/metabolismo , Apoptosis/efectos de los fármacos , Apoptosis/genética , Ciclo Celular/efectos de los fármacos , Ciclo Celular/genética , Muerte Celular/efectos de los fármacos , Muerte Celular/genética , Línea Celular Tumoral , Supervivencia Celular/genética , Cromatina/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Mitocondrias/efectos de los fármacos , Oligomicinas/farmacología , Reproducibilidad de los Resultados , Rotenona/administración & dosificación , Rotenona/farmacología
4.
Front Cell Dev Biol ; 8: 212, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32300591

RESUMEN

MGAT1 and complex N-glycans are required for spermatogenesis and fertility. Conditional deletion of Mgat1 in spermatogonia (Mgat1 cKO) causes reduced ERK1/2 signaling and the formation of multinucleated germ cells (MNC). Here we show that glycomics analysis of N-glycans released from fixed testis sections and analyzed by MALDI imaging mass spectrometry (MALDI-IMS) revealed a loss of MGAT1 activity in all germ cells based on the accumulation of the oligomannosyl substrate of MGAT1. To determine in which type of germ cell MGAT1 is essential for spermatogenesis, we generated Mgat1 cKO males that also expressed a Mgat1-HA transgene under the control of a germ cell-specific promoter - Stra8 for spermatogonia, Ldhc for spermatocytes and Prm1 for spermatids. Males expressing each Mgat1-HA transgene were fertile, and both males and females transmitted each transgene. When Stra8-Mgat1-HA was expressed in Mgat1 cKO males, spermatogenesis was rescued based on the morphology of testis sections, the complement of N-glycans on basigin, lectin histochemistry, MALDI-IMS, and fertility. By contrast, neither Ldhc-Mgat1-HA expressed in spermatocytes, nor the Prm1-Mgat1-HA transgene expressed in spermatids rescued spermatogenesis or fertility in Mgat1 cKO males. Therefore, MGAT1 must be expressed in spermatogonia for spermatogenesis to proceed normally.

5.
Sci Rep ; 10(1): 2135, 2020 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-32034218

RESUMEN

Male germ cells are sensitive to heat stress and testes must be maintained outside the body for optimal fertility. However, no germ cell intrinsic mechanism that protects from heat has been reported. Here, we identify the germ cell specific Golgi glycoprotein MGAT4D as a protector of male germ cells from heat stress. Mgat4d is highly expressed in spermatocytes and spermatids. Unexpectedly, when the Mgat4d gene was inactivated globally or conditionally in spermatogonia, or mis-expressed in spermatogonia, spermatocytes or spermatids, neither spermatogenesis nor fertility were affected. On the other hand, when males were subjected to mild heat stress of the testis (43 °C for 25 min), germ cells with inactivated Mgat4d were markedly more sensitive to the effects of heat stress, and transgenic mice expressing Mgat4d were partially protected from heat stress. Germ cells lacking Mgat4d generally mounted a similar heat shock response to control germ cells, but could not maintain that response. Several pathways activated by heat stress in wild type were induced to a lesser extent in Mgat4d[-/-] heat-stressed germ cells (NFκB response, TNF and TGFß signaling, Hif1α and Myc genes). Thus, the Golgi glycoprotein MGAT4D is a novel, intrinsic protector of male germ cells from heat stress.


Asunto(s)
Células Germinativas/metabolismo , Glicoproteínas/metabolismo , Aparato de Golgi/metabolismo , Trastornos de Estrés por Calor/metabolismo , Respuesta al Choque Térmico/fisiología , Proteínas de la Membrana/metabolismo , Testículo/metabolismo , Animales , Calor , Masculino , Ratones , Ratones Endogámicos C57BL , Espermátides/metabolismo , Espermatocitos/metabolismo , Espermatogénesis/fisiología , Espermatogonias/metabolismo , Espermatozoides/metabolismo
6.
BMC Dev Biol ; 19(1): 19, 2019 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-31590629

RESUMEN

BACKGROUND: Mouse NOTCH1 carries a highly conserved O-fucose glycan at Thr466 in epidermal growth factor-like repeat 12 (EGF12) of the extracellular domain. O-Fucose at this site has been shown by X-ray crystallography to be recognized by both DLL4 and JAG1 Notch ligands. We previously showed that a Notch1 Thr466Ala mutant exhibits very little ligand-induced NOTCH1 signaling in a reporter assay, whereas a Thr466Ser mutation enables the transfer of O-fucose and reverts the NOTCH1 signaling defect. We subsequently generated a mutant mouse with the Thr466Ala mutation termed Notch1[12f](Notch1tm2Pst). Surprisingly, homozygous Notch1[12f/12f] mutants on a mixed background were viable and fertile. RESULTS: We now report that after backcrossing to C57BL/6 J mice for 11-15 generations, few homozygous Notch1[12f/12f] embryos were born. Timed mating showed that embryonic lethality occurred by embryonic day (E) ~E11.5, somewhat delayed compared to mice lacking Notch1 or Pofut1 (the O-fucosyltransferase that adds O-fucose to Notch receptors), which die at ~E9.5. The phenotype of C57BL/6 J Notch1[12f/12f] embryos was milder than mutants affected by loss of a canonical Notch pathway member, but disorganized vasculogenesis in the yolk sac, delayed somitogenesis and development were characteristic. In situ hybridization of Notch target genes Uncx4.1 and Dll3 or western blot analysis of NOTCH1 cleavage did not reveal significant differences at E9.5. However, qRT-PCR of head cDNA showed increased expression of Dll3, Uncx4.1 and Notch1 in E9.5 Notch1[12f/12f] embryos. Sequencing of cDNA from Notch1[12f/12f] embryo heads and Southern analysis showed that the Notch1[12f] locus was intact following backcrossing. We therefore looked for evidence of modifying gene(s) by crossing C57BL/6 J Notch1 [12f/+] mice to 129S2/SvPasCrl mice. Intercrosses of the F1 progeny gave viable F2 Notch1[12f/12f] mice. CONCLUSION: We conclude that the 129S2/SvPasCrl genome contains a dominant modifying gene that rescues the functions of NOTCH1[12f] in signaling. Identification of the modifying gene has the potential to illuminate novel factor(s) that promote Notch signaling when an O-fucose glycan is absent from EGF12 of NOTCH1.


Asunto(s)
Sustitución de Aminoácidos , Embrión de Mamíferos/anatomía & histología , Genes Modificadores , Endogamia/métodos , Receptor Notch1/genética , Alanina/metabolismo , Animales , Desarrollo Embrionario , Femenino , Fucosa/metabolismo , Genoma , Homocigoto , Masculino , Ratones , Ratones Endogámicos C57BL , Fenotipo , Dominios Proteicos , Receptor Notch1/química , Receptor Notch1/metabolismo , Treonina/metabolismo
7.
Medisan ; 22(5)mayo 2018. tab
Artículo en Español | LILACS | ID: biblio-955036

RESUMEN

Se realizó un estudio descriptivo y transversal de 125 pacientes, atendidas en la Consulta de Patología de Cuello, perteneciente al área de salud del Policlínico Universitario Municipal de Santiago de Cuba, durante el 2016, con vistas a describir los principales factores que propiciaron la aparición del cáncer cervicouterino. En la serie predominaron la neoplasia intracervical de grado I, la cervicitis crónica y las mujeres que comenzaron sus relaciones sexuales a los 15-19 años de edad (68,8 por ciento). Resultó significativa la presencia de leucorrea, sangrado poscoital y el virus del papiloma humano como antecedente de infección de transmisión sexual. Se destacó el papel negativo del cambio frecuente de pareja. Quedó demostrada la necesidad de que los profesionales de la salud consoliden sus conocimientos teóricos y prácticos sobre el cáncer cervicouterino, con énfasis en la educación sexual y reproductiva de las féminas, a través de la promoción y prevención de salud en la atención primaria


A descriptive and cross-sectional study of 125 patients, assisted in the Neck Pathology Service, belonging to the health area of the Municipal University Polyclinic in Santiago de Cuba, was carried out during 2016, aimed at describing the main factors that favored the emergence of cervical cancer. In the series there was a prevalence of grade I intracervical neoplasm, chronic cervicitis and women whose sexual relationships began at 15-19 years (68.8 percent). The presence of leukorrhea, postcoital bledding and human papilloma virus as history of sexual transmitted infection was significant. The necessity that health professionals consolidate their theoretical and practical knowledge on cervical cancer, with emphasis in the sexual and reproductive education of women, through the promotion and health prevention in primary care was demonstrated


Asunto(s)
Humanos , Femenino , Adolescente , Adulto , Neoplasias del Cuello Uterino/diagnóstico , Neoplasias del Cuello Uterino/prevención & control , Neoplasias del Cuello Uterino/epidemiología , Atención Primaria de Salud , Estudios Transversales , Factores de Riesgo
8.
Medisan ; 22(4)abr. 2018. tab
Artículo en Español | CUMED | ID: cum-70235

RESUMEN

Se realizó una investigación observacional, descriptiva y transversal de 95 niños en las edades de 0 a 10 años, con diagnóstico de enfermedad diarreica aguda a causa del Vibrio cholerae, atendidos en el Hospital Infantil Norte Dr Juan de la Cruz Martínez Maceira de Santiago de Cuba, durante el 2016, a fin de caracterizarles según algunas variables clínicas y epidemiológicas. Entre los principales resultados se obtuvo que el grupo etario más afectado fuera el de 0 a 11 meses y el municipio con mayor número de casos el de Santiago de Cuba, los que correspondieron fundamentalmente a las áreas de salud de los policlínicos Frank País García, José Martí Pérez y Josué País García. Asimismo se evidenció que la principal manifestación del proceso infeccioso fue la diarrea líquida y la complicación más frecuente, la deshidratación isotónica moderada. Todos los niños egresaron vivos, lo cual demuestra la eficacia de la atención médica en el territorio suroriental de Cuba(AU)


An observational, descriptive and cross-sectional investigation of 95 children aged 0 to 10, with diagnosis of acute diarrheal disease due to Vibrio cholerae, assisted in Dr Juan de la Cruz Martínez Maceira Northern Children Hospital in Santiago de Cuba, was carried out during 2016, in order to characterize them according to some clinical and epidemiological variables. Among the predominant results there were the 0 to 11 months age group as the most affected and the presence of a higher number of cases in Santiago de Cuba municipality, that corresponded mainly to the health areas of Frank País García, José Martí Pérez and Josué País García polyclinics. Also it was evidenced that the main manifestation of the infectious process was the liquid diarrhea and the most frequent complication, the moderate isotonic dehydration. None of the children died, which demonstrates the effectiveness of medical care in the southeastern territory of Cuba(AU)


Asunto(s)
Humanos , Masculino , Femenino , Lactante , Niño , Disentería , Diarrea , Diarrea Infantil , Vibrio cholerae , Cólera , Epidemiología Descriptiva , Estudios Transversales , Estudio Observacional
9.
Medisan ; 22(4)abr. 2018. tab
Artículo en Español | LILACS | ID: biblio-894709

RESUMEN

Se realizó una investigación observacional, descriptiva y transversal de 95 niños en las edades de 0 a 10 años, con diagnóstico de enfermedad diarreica aguda a causa del Vibrio cholerae, atendidos en el Hospital Infantil Norte Dr Juan de la Cruz Martínez Maceira de Santiago de Cuba, durante el 2016, a fin de caracterizarles según algunas variables clínicas y epidemiológicas. Entre los principales resultados se obtuvo que el grupo etario más afectado fuera el de 0 a 11 meses y el municipio con mayor número de casos el de Santiago de Cuba, los que correspondieron fundamentalmente a las áreas de salud de los policlínicos Frank País García, José Martí Pérez y Josué País García. Asimismo se evidenció que la principal manifestación del proceso infeccioso fue la diarrea líquida y la complicación más frecuente, la deshidratación isotónica moderada. Todos los niños egresaron vivos, lo cual demuestra la eficacia de la atención médica en el territorio suroriental de Cuba


An observational, descriptive and cross-sectional investigation of 95 children aged 0 to 10, with diagnosis of acute diarrheal disease due to Vibrio cholerae, assisted in Dr Juan de la Cruz Martínez Maceira Northern Children Hospital in Santiago de Cuba, was carried out during 2016, in order to characterize them according to some clinical and epidemiological variables. Among the predominant results there were the 0 to 11 months age group as the most affected and the presence of a higher number of cases in Santiago de Cuba municipality, that corresponded mainly to the health areas of Frank País García, José Martí Pérez and Josué País García polyclinics. Also it was evidenced that the main manifestation of the infectious process was the liquid diarrhea and the most frequent complication, the moderate isotonic dehydration. None of the children died, which demonstrates the effectiveness of medical care in the southeastern territory of Cuba


Asunto(s)
Humanos , Masculino , Femenino , Recién Nacido , Lactante , Preescolar , Niño , Vibrio cholerae , Deshidratación/tratamiento farmacológico , Diarrea/epidemiología , Diarrea Infantil/epidemiología , Estudios Transversales , Disentería , Estudio Observacional
10.
Sci Rep ; 8(1): 2022, 2018 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-29386567

RESUMEN

Mechanisms that regulate spermatogenesis in mice are important to define as they often apply to fertility in man. We previously showed that conditional deletion of the mouse Mgat1 gene (Mgat1 cKO) in spermatogonia causes a germ-cell autonomous defect leading to infertility. MGAT1 is the N-acetylglucosaminyltransferase (GlcNAcT-I) that initiates the synthesis of complex N-glycans. Mechanistic bases of MGAT1 loss were investigated in germ cells from 22- and 23-day males, before any changes in germ cell morphology were apparent. Gene expression changes induced by deletion of Mgat1 were determined using the Affymetrix gene chip Mouse Mogene 2.0 ST array, and relationships were investigated by bioinformatics including Gene Ontology (GO), Ingenuity Pathway Analysis (IPA), and Gene Set Enrichment Analysis (GSEA). The loss of complex N-glycans promoted the premature up-regulation of genes normally expressed later in spermatogenesis and spermiogenesis, and IPA and GSEA implicated ERK signaling. EGFR and PDGFRA transcripts and ERK1/2 signaling were reduced in 22-day Mgat1 cKO germ cells. Basigin, a germ cell target of MGAT1, activated ERK1/2 in CHO cells, but not in a Lec1 CHO mutant that lacks MGAT1 and complex N-glycans. Thus, MGAT1 is required to regulate ERK1/2 signaling during spermatogenesis, potentially via different mechanisms.


Asunto(s)
Aciltransferasas/metabolismo , Sistema de Señalización de MAP Quinasas , Polisacáridos/metabolismo , Espermatogénesis , Espermatozoides/metabolismo , Aciltransferasas/genética , Animales , Basigina/genética , Basigina/metabolismo , Células CHO , Células Cultivadas , Cricetinae , Cricetulus , Receptores ErbB/genética , Receptores ErbB/metabolismo , Masculino , Ratones , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , N-Acetilglucosaminiltransferasas , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/genética , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Espermatozoides/citología
11.
Open Biol ; 6(10)2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27805902

RESUMEN

Recurrent spontaneous abortion (RSA) is a common cause of infertility, but previous attempts at identifying RSA causative genes have been relatively unsuccessful. Such failure to describe RSA aetiological genes might be explained by the fact that reproductive phenotypes should be considered as quantitative traits resulting from the intricate interaction of numerous genetic, epigenetic and environmental factors. Here, we studied an interspecific recombinant congenic strain (IRCS) of Mus musculus from the C57BL6/J strain of mice harbouring an approximate 5 Mb DNA fragment from chromosome 13 from Mus spretus mice (66H-MMU13 strain), with a high rate of embryonic resorption (ER). Transcriptome analyses of endometrial and placental tissues from these mice showed a deregulation of many genes associated with the coagulation and inflammatory response pathways. Bioinformatics approaches led us to select Foxd1 as a candidate gene potentially related to ER and RSA. Sequencing analysis of Foxd1 in the 66H-MMU13 strain, and in 556 women affected by RSA and 271 controls revealed non-synonymous sequence variants. In vitro assays revealed that some led to perturbations in FOXD1 transactivation properties on promoters of genes having key roles during implantation/placentation, suggesting a role of this gene in mammalian implantation processes.


Asunto(s)
Aborto Espontáneo/genética , Pérdida del Embrión/genética , Factores de Transcripción Forkhead/genética , Polimorfismo de Nucleótido Simple , Animales , Células COS , Línea Celular , Chlorocebus aethiops , Pérdida del Embrión/veterinaria , Femenino , Perfilación de la Expresión Génica/métodos , Estudios de Asociación Genética , Humanos , Ratones , Ratones Endogámicos C57BL , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Placenta/química , Embarazo , Regiones Promotoras Genéticas , Útero/química
12.
Biol Reprod ; 86(6): 179, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22492969

RESUMEN

To identify roles in spermatogenesis for major subclasses of N- and O-glycans and Notch signaling, male mice carrying floxed C1galt1, Pofut1, Notch1 or Mgat1 alleles and a testis-specific Cre recombinase transgene were generated. T-synthase (C1GALT1) transfers Gal to generate core 1 and core 2 mucin O-glycans; POFUT1 transfers O-fucose to particular epidermal growth factor-like repeats and is essential for canonical Notch signaling; and MGAT1 (GlcNAcT-I) transfers GlcNAc to initiate hybrid and complex N-glycan synthesis. Cre recombinase transgenes driven by various promoters were investigated, including Stra8-iCre expressed in spermatogonia, Sycp1-Cre expressed in spermatocytes, Prm1-Cre expressed in spermatids, and AMH-Cre expressed in Sertoli cells. All Cre transgenes deleted floxed alleles, but efficiencies varied widely. Stra8-iCre was the most effective, deleting floxed Notch1 and Mgat1 alleles with 100% efficiency and floxed C1galt1 and Pofut1 alleles with ~80% efficiency, based on transmission of deleted alleles. Removal of C1galt1, Pofut1, or Notch1 in spermatogonia had no effect on testicular weight, histology, or fertility. However, males in which the synthesis of complex N-glycans was blocked by deletion of Mgat1 in spermatogonia did not produce sperm. Spermatogonia, spermatocytes, and spermatids were generated, but most spermatids formed giant multinucleated cells or symplasts, and apoptosis was increased. Therefore, although core 1 and 2 mucin O-glycans, NOTCH1, POFUT1, O-fucose glycans, and Notch signaling are dispensable, MGAT1 and complex N-glycans are essential for spermatogenesis.


Asunto(s)
Aciltransferasas/metabolismo , Polisacáridos/biosíntesis , Receptor Notch1/metabolismo , Espermatogénesis , Espermatozoides/metabolismo , Aciltransferasas/genética , Animales , Masculino , Ratones , Ratones Transgénicos , N-Acetilglucosaminiltransferasas
13.
Hum Mol Genet ; 18(4): 632-44, 2009 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-19010791

RESUMEN

FOXL2 is a forkhead transcription factor, essential for ovarian function, whose mutations are responsible for the blepharophimosis syndrome, characterized by craniofacial defects, often associated with premature ovarian failure. Here, we show that cell stress upregulates FOXL2 expression in an ovarian granulosa cell model. Increased FOXL2 transcription might be mediated at least partly by self-activation. Moreover, using 2D-western blot, we show that the response of FOXL2 to stress correlates with a dramatic remodeling of its post-translational modification profile. Upon oxidative stress, we observe an increased recruitment of FOXL2 to several stress-response promoters, notably that of the mitochondrial manganese superoxide dismutase (MnSOD). Using several reporter systems, we show that FOXL2 transactivation is enhanced in this context. Models predict that gene upregulation in response to a signal should eventually be counterbalanced to restore the initial steady state. In line with this, we find that FOXL2 activity is repressed by the SIRT1 deacetylase. Interestingly, we demonstrate that SIRT1 transcription is, in turn, directly upregulated by FOXL2, which closes a negative-feedback loop. The regulatory relationship between FOXL2 and SIRT1 prompted us the test action of nicotinamide, an inhibitor of sirtuins, on FoxL2 expression/activity. According to our expectations, nicotinamide treatment increases FoxL2 transcription. Finally, we show that 11 disease-causing mutations in the ORF of FOXL2 induce aberrant regulation of FOXL2 and/or regulation of the FOXL2 stress-response target gene MnSOD. Taken together, our results establish that FOXL2 is an actor of the stress response and provide new insights into the pathogenic consequences of FOXL2 mutations.


Asunto(s)
Blefarofimosis/genética , Factores de Transcripción Forkhead/genética , Regulación de la Expresión Génica , Mutación , Estrés Oxidativo , Insuficiencia Ovárica Primaria/genética , Blefarofimosis/metabolismo , Línea Celular , Femenino , Proteína Forkhead Box L2 , Factores de Transcripción Forkhead/metabolismo , Células de la Granulosa/metabolismo , Humanos , Insuficiencia Ovárica Primaria/metabolismo , Regiones Promotoras Genéticas , Sirtuina 1 , Sirtuinas/genética , Sirtuinas/metabolismo , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo , Transcripción Genética
14.
Hum Mol Genet ; 17(20): 3118-27, 2008 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-18635577

RESUMEN

The Forkhead transcription factor FOXL2 plays a crucial role in ovarian development and maintenance. In humans, its mutations lead to craniofacial abnormalities, isolated or associated with ovarian dysfunction. Using a combinatorial approach, we identified and characterized a FoxL2 response element (FLRE) and showed that it is highly specific and that it diverges from that of other Forkhead transcription factors. This specificity should prevent aberrant regulation of FOXL2 targets by other members of the family and should prevent ectopic activation of the ovarian differentiation program in testes. We provide evidence that the FLRE is used in naturally occurring promoters. We show that polyAlanine expansions of FOXL2, which are the most frequent pathogenic mutations, induce a length-dependent loss of response on different artificial promoter reporters depending on the number and sequence of the FLREs that they contain. Thus, we provide clear mechanistic evidence explaining how the architecture of promoters influences their sensitivity to decreased transcription factor availability. Furthermore, we speculate that the generally absent ovarian phenotype of patients carrying the most frequent polyAlanine expansion should come from its ability to properly regulate high-affinity ovarian targets. The existence of critical high-affinity ovarian targets would be compatible with the role of FOXL2 in reproduction and ensure developmental and functional robustness. Taken together, our results give mechanistic insights on the molecular pathogenesis of FOXL2 polyAlanine expansions.


Asunto(s)
Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/metabolismo , Mutación , Elementos de Respuesta , Alelos , Secuencia de Bases , Línea Celular , ADN/genética , ADN/metabolismo , Femenino , Proteína Forkhead Box L2 , Factores de Transcripción Forkhead/química , Células de la Granulosa/metabolismo , Humanos , Ovario/crecimiento & desarrollo , Ovario/metabolismo , Péptidos/química , Péptidos/genética , Regiones Promotoras Genéticas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transfección , Expansión de Repetición de Trinucleótido
15.
Hum Mutat ; 29(8): E123-31, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18484667

RESUMEN

Mutations of the transcription factor FOXL2, involved in cranio-facial and ovarian development lead to the Blepharophimosis-Ptosis-Epicanthus Inversus Syndrome (BPES) in human. Here, we describe nine mutations in the open reading frame of FOXL2. Six of them are novel: c.292T>A (p.Trp98Arg), c.323T>C (p.Leu108Pro), c.650C>G (p.Ser217Cys) and three frameshifts. We have performed localization and functional studies for three of them. We have observed a strong cytoplasmic mislocalization induced by the missense mutation p.Leu108Pro located in the forkhead (FKH) domain of FOXL2. In line with this, transcriptional activity assays confirmed the loss-of-function induced by this variant. Interestingly, the novel mutation p.Ser217Cys, mapping between the FKH and the polyalanine domain of FOXL2 and producing a mild eyelid phenotype, led to normal localization and transactivation. We have also modeled the structure of the FKH domain to explore the potential structural impact of the mutations reported here and other previously reported ones. This analysis shows that mutants can be sorted into two classes: those that potentially alter protein-protein interactions and those that might disrupt the interactions with DNA. Our findings reveal new insights into the molecular effects of FOXL2 mutations, especially those affecting the FKH binding domain. (c) 2008 Wiley-Liss, Inc.


Asunto(s)
Blefarofimosis/genética , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/fisiología , Mutación , Animales , Células COS , Niño , Preescolar , Chlorocebus aethiops , Femenino , Proteína Forkhead Box L2 , Mutación del Sistema de Lectura , Humanos , Lactante , Masculino , Insuficiencia Ovárica Primaria/genética , Estructura Terciaria de Proteína
16.
Hum Mol Genet ; 17(7): 1010-9, 2008 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-18158309

RESUMEN

Polyalanine (polyAla) tract expansions have been associated with an increasing number of human diseases. Here, we have undertaken a functional study of the effects of polyAla expansions in the context of the transcription factor FOXL2, involved in cranio-facial and ovarian development. Using two cellular models, we show that FOXL2 polyAla expansions lead to protein mislocalization and aggregation in a length-dependent manner. The fraction of cells containing cytoplasmic staining displays a sigmoidal relationship with respect to the length of the polyAla tract, suggesting the existence of a threshold length above which protein mislocalization occurs. The existence of such a threshold might be rationalized if we consider that the longer the polyAla tract is, the higher its tendency to misfolding or to inducing spurious interactions with cytoplasmic components. To study the intranuclear dynamics of polyAla-expanded FOXL2, we performed fluorescence recovery after photobleaching experiments. The most unexpected result concerned the pathogenic protein containing 19 Ala residues in the run, which was virtually immobile, although this variant does not present a classical aggregation pattern. Luciferase assays and real time RT-PCR of many potential target genes showed that polyAla expansions induce different losses of activity according to the target promoters tested. We provide molecular explanations for these findings. Although our main focus is the mechanisms of pathogenesis of polyAla-expanded proteins, we discuss the potential relevance of polyAla length variation in micro- and macroevolution because polyAla-containing proteins tend to be transcription factors.


Asunto(s)
Anomalías Craneofaciales/genética , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/metabolismo , Ovario/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Expansión de Repetición de Trinucleótido , Animales , Células COS , Línea Celular Tumoral , Chlorocebus aethiops , Citoplasma/química , Citoplasma/metabolismo , Femenino , Recuperación de Fluorescencia tras Fotoblanqueo , Proteína Forkhead Box L2 , Factores de Transcripción Forkhead/química , Proteínas Fluorescentes Verdes/análisis , Proteínas Fluorescentes Verdes/metabolismo , Humanos , Espacio Intranuclear/metabolismo , Microscopía Fluorescente , Ovario/anomalías , Ovario/embriología , Péptidos/metabolismo , Transporte de Proteínas , Proteínas Recombinantes de Fusión/análisis , Proteínas Recombinantes de Fusión/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Transcripción/análisis , Transfección
17.
Proc Natl Acad Sci U S A ; 104(9): 3330-5, 2007 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-17360647

RESUMEN

FOXL2 is a gene encoding a forkhead transcription factor, whose mutations are responsible for the blepharophimosis-ptosis-epicanthus inversus syndrome that often involves premature ovarian failure. FOXL2 is one of the earliest ovarian markers and it offers, along with its targets, an excellent model to study ovarian development and function in normal and pathological conditions. We have recently shown that the aromatase gene is a target of FOXL2, and only three other targets have been reported so far. To detect potential transcriptional targets of FOXL2, we used DNA chips and quantitative PCR to compare the transcriptomes of granulosa-like cells overexpressing, or not, FOXL2. This analysis showed that mediators of inflammation, apoptotic and transcriptional regulators, genes involved in cholesterol metabolism, and genes encoding enzymes and transcription factors involved in reactive oxygen species detoxification were up-regulated. On the other hand, FOXL2 down-regulated the transcription of several genes involved in proteolysis and signal transduction and in transcription regulation. A bioinformatic analysis was conducted to discriminate between potential target promoters activated and repressed by FOXL2. In addition, the promoters of strongly activated genes were enriched in forkhead recognition sites, suggesting that these genes might be direct FOXL2 targets. Altogether, these results provide insight into the activity of FOXL2 and may help in understanding the mechanisms of pathogenesis of FOXL2 mutations if the targets prove to be the same in the ovary.


Asunto(s)
Anomalías Múltiples/genética , Blefarofimosis/genética , Factores de Transcripción Forkhead/metabolismo , Regulación de la Expresión Génica , Genes/genética , Apoptosis/genética , Quimiocinas/genética , Biología Computacional , Proteína Forkhead Box L2 , Factores de Transcripción Forkhead/genética , Humanos , Análisis de Secuencia por Matrices de Oligonucleótidos , Péptido Hidrolasas/genética , Reacción en Cadena de la Polimerasa , Análisis de Componente Principal , Transducción de Señal/genética
18.
J Mol Endocrinol ; 36(3): 399-413, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16720712

RESUMEN

Previous studies have equated FOXL2 as a crucial actor in the ovarian differentiation process in different vertebrate species. Its transcriptional extinction in the polled intersex syndrome (PIS) leads primarily to a drastic decrease of aromatase (CYP19) expression in the first steps of goat ovarian development. In this study, we provide a better characterization of early ovarian development in goat, and we provide experimental evidence demonstrating that FOXL2 represents a direct transcriptional activator of the CYP19 gene through its ovarian-specific promoter 2. Moreover, the ovarian location of FOXL2 and CYP19 proteins, together with their expression profiles in the female gonads, stress the involvement of FOXL2 co-factor(s) for regulating CYP19 transcription. Expressional analyses show that activin-betaA can be considered as a strong candidate for being one of these FOXL2 co-factors. Finally, we discuss evidence for a role of activin and estrogens in somatic and germinal cell proliferation occurring before germ cell meiosis. This period, of 20 days in goat, seems to have no equivalent in mouse. This species-specific difference could explain the phenotype discrepancy observed between XX goat PIS(-/-) and XX mouse Foxl2(-/-).


Asunto(s)
Aromatasa/metabolismo , Factores de Transcripción Forkhead/metabolismo , Regulación Enzimológica de la Expresión Génica , Ovario/embriología , Ovario/crecimiento & desarrollo , Transcripción Genética , 3-Hidroxiesteroide Deshidrogenasas/genética , 3-Hidroxiesteroide Deshidrogenasas/metabolismo , Receptores de Activinas/genética , Receptores de Activinas/metabolismo , Animales , Aromatasa/genética , Células Cultivadas , Femenino , Factores de Transcripción Forkhead/genética , Cabras , Humanos , Inhibinas/genética , Inhibinas/metabolismo , Masculino , Ratones , Ovario/citología , Ovario/fisiología , Regiones Promotoras Genéticas , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Ovinos , Síndrome
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...