RESUMO
Börjeson-Forssman-Lehmann syndrome (BFLS) is an intellectual disability and endocrine disorder caused by plant homeodomain finger 6 (PHF6) mutations. Individuals with BFLS present with short stature. We report a mouse model of BFLS, in which deletion of Phf6 causes a proportional reduction in body size compared with control mice. Growth hormone (GH) levels were reduced in the absence of PHF6. Phf6-/Y animals displayed a reduction in the expression of the genes encoding GH-releasing hormone (GHRH) in the brain, GH in the pituitary gland and insulin-like growth factor 1 (IGF1) in the liver. Phf6 deletion specifically in the nervous system caused a proportional growth defect, indicating a neuroendocrine contribution to the phenotype. Loss of suppressor of cytokine signaling 2 (SOCS2), a negative regulator of growth hormone signaling partially rescued body size, supporting a reversible deficiency in GH signaling. These results demonstrate that PHF6 regulates the GHRH/GH/IGF1 axis.
Assuntos
Regulação para Baixo , Epilepsia/metabolismo , Face/anormalidades , Dedos/anormalidades , Transtornos do Crescimento/metabolismo , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Hormônio do Crescimento/metabolismo , Hipogonadismo/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Deficiência Intelectual Ligada ao Cromossomo X/metabolismo , Obesidade/metabolismo , Proteínas Repressoras/metabolismo , Transdução de Sinais , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Epilepsia/sangue , Epilepsia/patologia , Face/patologia , Dedos/patologia , Transtornos do Crescimento/sangue , Transtornos do Crescimento/patologia , Hormônio do Crescimento/sangue , Hipogonadismo/sangue , Hipogonadismo/patologia , Hipotálamo/metabolismo , Fator de Crescimento Insulin-Like I/genética , Masculino , Deficiência Intelectual Ligada ao Cromossomo X/sangue , Deficiência Intelectual Ligada ao Cromossomo X/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Sistema Nervoso/metabolismo , Obesidade/sangue , Obesidade/patologia , Especificidade de Órgãos , Hipófise/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Supressoras da Sinalização de Citocina/metabolismoRESUMO
Understanding the mechanisms of activity-dependent gene transcription underlying adaptive behaviors is challenging at neuronal-subtype resolution. Using cell-type specific molecular analysis in agouti-related peptide (AgRP) neurons, we reveal that the profound hunger-induced transcriptional changes greatly depend on plant homeodomain finger protein 6 (PHF6), a transcriptional repressor enriched in AgRP neurons. Loss of PHF6 in the satiated mice results in a hunger-state-shifting transcriptional profile, while hunger fails to further induce a rapid and robust activity-dependent gene transcription in PHF6-deficient AgRP neurons. We reveal that PHF6 binds to the promoters of a subset of immediate-early genes (IEGs) and that this chromatin binding is dynamically regulated by hunger state. Depletion of PHF6 decreases hunger-driven feeding motivation and makes the mice resistant to body weight gain under repetitive fasting-refeeding conditions. Our work identifies a neuronal subtype-specific transcriptional repressor that modulates transcriptional profiles in different nutritional states and enables adaptive eating behavior.
Assuntos
Cromatina/metabolismo , Redes Reguladoras de Genes/genética , Fome/fisiologia , Neurônios/metabolismo , Proteínas Repressoras/metabolismo , Proteína Relacionada com Agouti/metabolismo , Animais , Dieta , Regulação para Baixo/genética , Comportamento Alimentar , Ontologia Genética , Genes Precoces , Hipotálamo/metabolismo , Camundongos Endogâmicos C57BL , Motivação , Regiões Promotoras Genéticas/genética , Ligação Proteica , Proteínas Repressoras/genética , Resposta de Saciedade , Aumento de PesoRESUMO
Yin and yang 1 (YY1) is a well-known zinc-finger transcription factor with crucial roles in normal development and malignancy. YY1 acts both as a repressor and as an activator of gene expression. We have identified 23 individuals with de novo mutations or deletions of YY1 and phenotypic features that define a syndrome of cognitive impairment, behavioral alterations, intrauterine growth restriction, feeding problems, and various congenital malformations. Our combined clinical and molecular data define "YY1 syndrome" as a haploinsufficiency syndrome. Through immunoprecipitation of YY1-bound chromatin from affected individuals' cells with antibodies recognizing both ends of the protein, we show that YY1 deletions and missense mutations lead to a global loss of YY1 binding with a preferential retention at high-occupancy sites. Finally, we uncover a widespread loss of H3K27 acetylation in particular on the YY1-bound enhancers, underscoring a crucial role for YY1 in enhancer regulation. Collectively, these results define a clinical syndrome caused by haploinsufficiency of YY1 through dysregulation of key transcriptional regulators.
Assuntos
Cromatina/metabolismo , Haploinsuficiência/genética , Deficiência Intelectual/genética , Transcrição Gênica , Fator de Transcrição YY1/genética , Acetilação , Adolescente , Sequência de Bases , Pré-Escolar , Imunoprecipitação da Cromatina , Estudos de Coortes , Elementos Facilitadores Genéticos/genética , Feminino , Ontologia Genética , Haplótipos/genética , Hemizigoto , Histonas/metabolismo , Humanos , Linfócitos/metabolismo , Masculino , Metilação , Modelos Moleculares , Mutação de Sentido Incorreto/genética , Ligação Proteica/genética , Domínios Proteicos , Fator de Transcrição YY1/químicaRESUMO
The discovery of mutations causing human disease has so far been biased toward protein-coding regions. Having excluded all annotated coding regions, we performed targeted massively parallel resequencing of the nonrepetitive genomic linkage interval at Xq28 of family MRX3. We identified in the binding site of transcription factor YY1 a regulatory mutation that leads to overexpression of the chromatin-associated transcriptional regulator HCFC1. When tested on embryonic murine neural stem cells and embryonic hippocampal neurons, HCFC1 overexpression led to a significant increase of the production of astrocytes and a considerable reduction in neurite growth. Two other nonsynonymous, potentially deleterious changes have been identified by X-exome sequencing in individuals with intellectual disability, implicating HCFC1 in normal brain function.