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We encountered a pediatric case of pulmonary hypertension triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. A 14-year-old girl was brought to the emergency department of our hospital with fever, respiratory distress, and impaired consciousness. She tested positive for SARS-CoV-2 upon a polymerase chain reaction examination and had prolonged hypoxemia without pneumonia. An echocardiography revealed elevated right ventricular pressure. She was diagnosed with pilocytic astrocytoma at the age of 10 years and underwent a resection of a pituitary tumor. Hormone replacement therapy was administered postoperatively, but her growth hormones were not activated because of concerns about tumor recurrence. Echocardiography at the age of 13 years showed normal right ventricular pressure. On admission, she had an abnormal liver function, elevated liver fibrosis markers, a decreased platelet count, and hepatosplenomegaly, suggesting pulmonary and portal hypertension. The diagnosis was pulmonary hypertension associated with SARS-CoV-2 infection. The mechanism of the pulmonary hypertension was thought to be portal hypertension owing to growth hormone deficiency and SARS-CoV-2 infection. The patient's symptoms improved with oxygenation and bed rest without additional targeted pulmonary hypertension therapy, and her right ventricular pressure decreased. This case demonstrates that a pediatric patient with subclinical pulmonary hypertension may develop pulmonary hypertension triggered by SARS-CoV-2 infection.
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BACKGROUND: Catch-up growth issues among children born small for gestational age (SGA) present a substantial public health challenge. Prenatal exposure to heavy metals can cause adverse effects on birth weight. However, comprehensive studies on the accurate assessment of individual blood concentrations of heavy metals and their effect on the failure to achieve catch-up growth remain unavailable. This study aimed to evaluate the effects of uterine exposure to toxic metals cadmium, lead, and mercury and essential trace metals manganese and selenium at low concentrations on the postnatal growth of children born SGA. METHODS: Data on newborn birth size and other factors were obtained from the medical record transcripts and self-administered questionnaires of participants in the Japan Environment and Children's Study. The blood concentrations of lead, cadmium, mercury, selenium, and manganese in pregnant women in their second or third trimester were determined by inductively coupled plasma mass spectrometry. These heavy metal concentrations were also assessed in pregnant women's cord blood. Furthermore, the relationship between each heavy metal and height measure/catch-up growth in SGA children aged 4 years was analyzed using linear and logistic regression methods. These models were adjusted for confounders. RESULTS: We studied 4683 mother-child pairings from 103,060 pregnancies included in the Japan Environment and Children's Study. Of these, 278 pairs were also analyzed using cord blood. At 3 and 4 years old, 10.7% and 9.0% of children who were born below the 10th percentile of body weight had height standard deviation scores (SDSs) below 2, respectively. Cord blood cadmium concentrations were associated with the inability to catch up in growth by 3 or 4 years old and the height SDS at 3 years old. In maternal blood, only manganese was positively associated with the height SDS of SGA children aged 2 years; however, it was not significantly associated with catch-up growth in these children. CONCLUSION: Cadmium exposure is associated with failed catch-up development in SGA children. These new findings could help identify children highly at risk of failing to catch up in growth, and could motivate the elimination of heavy metal (especially cadmium) pollution to improve SGA children's growth.
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Mercurio , Metales Pesados , Selenio , Recién Nacido , Humanos , Femenino , Embarazo , Preescolar , Sangre Fetal , Cadmio , Edad Gestacional , Manganeso , Japón/epidemiología , Recién Nacido Pequeño para la Edad Gestacional , Retardo del Crecimiento FetalRESUMEN
Werner syndrome (WS) is a hereditary premature aging disorder characterized by visceral fat accumulation and subcutaneous lipoatrophy, resulting in severe insulin resistance. However, its underlying mechanism remains unclear. In this study, we show that senescence-associated inflammation and suppressed adipogenesis play a role in subcutaneous adipose tissue reduction and dysfunction in WS. Clinical data from four Japanese patients with WS revealed significant associations between the decrease of areas of subcutaneous fat and increased insulin resistance measured by the glucose clamp. Adipose-derived stem cells from the stromal vascular fraction derived from WS subcutaneous adipose tissues (WSVF) showed early replicative senescence and a significant increase in the expression of senescence-associated secretory phenotype (SASP) markers. Additionally, adipogenesis and insulin signaling were suppressed in WSVF, and the expression of adipogenesis suppressor genes and SASP-related genes was increased. Rapamycin, an inhibitor of the mammalian target of rapamycin (mTOR), alleviated premature cellular senescence, rescued the decrease in insulin signaling, and extended the lifespan of WS model of C. elegans. To the best of our knowledge, this study is the first to reveal the critical role of cellular senescence in subcutaneous lipoatrophy and severe insulin resistance in WS, highlighting the therapeutic potential of rapamycin for this disease.
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Resistencia a la Insulina , Insulinas , Lipodistrofia , Síndrome de Werner , Animales , Humanos , Síndrome de Werner/genética , Adipogénesis/genética , Caenorhabditis elegans , Senescencia Celular/genética , Grasa Subcutánea/metabolismo , Inflamación , Sirolimus , MamíferosRESUMEN
Regional anatomical structures of the brain are intimately connected to functions corresponding to specific regions and the temporospatial pattern of genetic expression and their functions from the fetal period to old age. Therefore, quantitative brain morphometry has often been employed in neuroscience investigations, while controlling for the scanner effect of the scanner is a critical issue for ensuring accuracy in brain morphometric studies of rare orphan diseases due to the lack of normal reference values available for multicenter studies. This study aimed to provide across-site normal reference values of global and regional brain volumes for each sex and age group in children and adolescents. We collected magnetic resonance imaging (MRI) examinations of 846 neurotypical participants aged 6.0-17.9 years (339 male and 507 female participants) from 5 institutions comprising healthy volunteers or neurotypical patients without neurological disorders, neuropsychological disorders, or epilepsy. Regional-based analysis using the CIVET 2.1.0. pipeline provided regional brain volumes, and the measurements were across-site combined using ComBat-GAM harmonization. The normal reference values of global and regional brain volumes and lateral indices in our study could be helpful for evaluating the characteristics of the brain morphology of each individual in a clinical setting and investigating the brain morphology of ultra-rare diseases.
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Purpose: Central precocious puberty (CPP) is puberty that occurs at an unusually early age with several negative psychological outcomes. There is a paucity of data on the morphological characteristics of the brain in CPP. This study aimed to determine the structural differences in the brain of patients with CPP. Methods: We performed voxel- and surface-based morphometric analyses of 1.5 T T1-weighted brain images scanned from 15 girls with CPP and 13 age-matched non-CPP controls (NC). All patients with CPP were diagnosed by gonadotropin-releasing hormone (GnRH) stimulation test. The magnetic resonance imaging (MRI) data were evaluated using Levene's test for equality of variances and a two-tailed unpaired t-test for equality of means. False discovery rate correction for multiple comparisons was applied using the Benjamini-Hochberg procedure. Results: Morphometric analyses of the brain scans identified 33 candidate measurements. Subsequently, increased thickness of the right precuneus was identified in the patients with CPP using general linear models and visualizations of cortical thickness with a t-statistical map and a random field theory map. Conclusion: The brain scans of the patients with CPP showed specific morphological differences to those of the control. The features of brain morphology in CPP identified in this study could contribute to further understanding the association between CPP and detrimental psychological outcomes.
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Existing evidence on the correlation between maternal vitamin D concentrations and birth outcomes is conflicting. Investigation of these associations requires accurate assessment of vitamin D status, especially in individuals with low 25-hydroxyvitamin D (25(OH)D) concentrations. This study examined the correlations between birth outcomes and the maternal vitamin D metabolite ratio (VMR) 1 (defined as the ratio of 24,25(OH)2D3 to 25(OH)D) and VMR2 (defined as the ratio of 3-epi-25(OH)D3 to 25(OH)D) using data from the Japan Environment and Children's Study at Chiba Regional Center. A total of 297 mother-neonate pairs were analyzed. Using liquid chromatography-tandem mass spectrometry, we measured 25(OH)D2, 25(OH)D3, 24,25(OH)2D3, and 3-epi-25(OH)D3 concentrations in maternal serum samples. These data were analyzed in relation to birth anthropometric data using multivariable linear regression. Of the study participants, 85.2% showed insufficient vitamin D concentrations. VMR1 was strongly correlated with 25(OH)D concentrations, whereas VMR2 showed a weak correlation. Only VMR2 was associated with all anthropometric data. VMR2 in pregnant women with low vitamin D blood concentrations is a useful marker for neonatal anthropometric data and is independent of 25(OH)D. Accurate measurement of vitamin D metabolites could help better understand the effects of vitamin D on birth outcomes.
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Mujeres Embarazadas , Espectrometría de Masas en Tándem , Calcifediol , Niño , Femenino , Humanos , Recién Nacido , Embarazo , Espectrometría de Masas en Tándem/métodos , Vitamina D , VitaminasRESUMEN
BACKGROUND: Growth restriction in the prenatal period is a significant public health concern. Metals can negatively affect birth size, and pregnant women may be exposed to metal mixtures. Comprehensive studies analyzing the effects of combined metal exposure with accurate individual blood metal concentrations are limited. The current study investigated the associations between maternal metal exposure and birth size in a large, nationwide Japanese cohort using individual and mixed model approaches. METHODS: Lead, cadmium, mercury, selenium, and manganese blood concentrations were measured in pregnant women in the Japan Environment and Children's Study (JECS). Measurements of infant birth size-including body weight, body length, and head and chest circumference-were collected. Linear and logistic regressions were used for birth size measurements and the odds of an infant being small in size for gestational age, respectively. Associations between combined metal mixtures and measurements at birth were evaluated using quantile g-computation and Bayesian kernel machine regression (BKMR). RESULTS: Of the 103,060 JECS pregnancies, 93,739 mother-infant pairs were analyzed. The linear regression models showed that lead, selenium, cadmium, and manganese-but not mercury-were associated with body weight. Cadmium was associated with length and chest circumference and mercury was associated with head circumference. Quantile g-computation revealed that manganese increased infant birth weight, length, head circumference, and chest circumference. Lead was the strongest negative factor for infant birth weight, length, head circumference, and chest circumference. The BKMR analysis revealed that the metals had an additive, rather than a synergistic effect. CONCLUSION: Metal exposure is associated with infant birth size, with lead and manganese playing a more significant role in Japan. The effects of prenatal combined metal exposure at low levels warrant public health attention.
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Mercurio , Selenio , Teorema de Bayes , Peso al Nacer , Cadmio , Niño , Femenino , Humanos , Lactante , Recién Nacido , Japón , Manganeso , Exposición Materna/efectos adversos , Metales , EmbarazoRESUMEN
We investigated umbilical cord serum microRNA (miRNA) profiles to identify biomarkers of a risk for obesity later in life. Participating children were divided into high- and low-risk groups of obesity based on the timing of adiposity rebound and the body mass index (BMI) at 5 years and randomly selected from each group for this study. 3D-Gene® Human miRNA Oligo Chip was performed using cord serum in five children of both groups. The most relevant miRNAs were confirmed in 33 children of the groups using the TaqMan® microRNA assay. We detected five cord serum miRNAs differentially expressed in children at high risk of obesity compared with the levels in children at low risk, namely, miR-516-3p and miR-130a-3p with increased levels and miR-1260b, miR-4709-3p, and miR194-3p with decreased levels. This study provides the first identification of altered umbilical cord serum miRNAs in childhood obesity.
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MicroARNs , Obesidad Infantil , Biomarcadores , Cohorte de Nacimiento , Niño , Estudios de Cohortes , Perfilación de la Expresión Génica , Humanos , MicroARNs/genética , Obesidad Infantil/genética , Proyectos Piloto , Cordón UmbilicalRESUMEN
Dysregulated glucagon secretion deteriorates glycemic control in type 1 and type 2 diabetes. Although insulin is known to regulate glucagon secretion via its cognate receptor (insulin receptor, INSR) in pancreatic alpha cells, the role of downstream proteins and signaling pathways underlying insulin's activities are not fully defined. Using in vivo (knockout) and in vitro (knockdown) studies targeting insulin receptor substrate (IRS) proteins, we compared the relative roles of IRS1 and IRS2 in regulating alpha cell function. Alpha cell-specific IRS1-knockout mice exhibited glucose intolerance and inappropriate glucagon suppression during glucose tolerance tests. In contrast, alpha cell-specific IRS2-knockout animals manifested normal glucose tolerance and suppression of glucagon secretion after glucose administration. Alpha cell lines with stable IRS1 knockdown could not repress glucagon mRNA expression and exhibited a reduction in phosphorylation of AKT Ser/Thr kinase (AKT, at Ser-473 and Thr-308). AlphaIRS1KD cells also displayed suppressed global protein translation, including reduced glucagon expression, impaired cytoplasmic Ca2+ response, and mitochondrial dysfunction. This was supported by the identification of novel IRS1-specific downstream target genes, Trpc3 and Cartpt, that are associated with glucagon regulation in alpha cells. These results provide evidence that IRS1, rather than IRS2, is a dominant regulator of pancreatic alpha cell function.
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Células Secretoras de Glucagón/patología , Glucagón/metabolismo , Intolerancia a la Glucosa/patología , Proteínas Sustrato del Receptor de Insulina/fisiología , Resistencia a la Insulina , Animales , Femenino , Células Secretoras de Glucagón/metabolismo , Intolerancia a la Glucosa/etiología , Intolerancia a la Glucosa/metabolismo , Masculino , Ratones , Ratones Noqueados , Fosforilación , Transducción de SeñalRESUMEN
The role of leptin receptor (OB-R) signaling in linking pluripotency with growth and development and the consequences of dysfunctional leptin signaling on progression of metabolic disease is poorly understood. Using a global unbiased proteomics approach we report that embryonic fibroblasts (MEFs) carrying the db/db mutation exhibit metabolic abnormalities, while their reprogrammed induced pluripotent stem cells (iPSCs) show altered expression of proteins involved in embryonic development. An upregulation in expression of eukaryotic translation initiation factor 4e (Eif4e) and Stat3 binding to the Eif4e promoter was supported by enhanced protein synthesis in mutant iPSCs. Directed differentiation of db/db iPSCs toward the neuronal lineage showed defects. Gene editing to correct the point mutation in db/db iPSCs using CRISPR-Cas9, restored expression of neuronal markers and protein synthesis while reversing the metabolic defects. These data imply a direct role for OB-R in regulating metabolism in embryonic fibroblasts and key developmental pathways in iPSCs.
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Factor 4E Eucariótico de Iniciación/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Biosíntesis de Proteínas , Receptores de Leptina/metabolismo , Factor de Transcripción STAT3/metabolismo , Transducción de Señal , Animales , Sistemas CRISPR-Cas , Diferenciación Celular , Linaje de la Célula , Factor 4E Eucariótico de Iniciación/genética , Fibroblastos/metabolismo , Edición Génica , Regulación del Desarrollo de la Expresión Génica , Metaboloma , Ratones , Ratones Noqueados , Neurogénesis , Proteínas , Proteómica , Receptores de Leptina/genéticaRESUMEN
Invariant natural killer T (iNKT) cells are innate-like CD1d-restricted T cells that express the invariant T cell receptor (TCR) composed of Vα24 and Vß11 in humans. iNKT cells specifically recognize glycolipid antigens such as α-galactosylceramide (αGalCer) presented by CD1d. iNKT cells show direct cytotoxicity toward CD1d-positive tumor cells, especially when CD1d presents glycolipid antigens. However, iNKT cell recognition of CD1d-negative tumor cells is unknown, and direct cytotoxicity of iNKT cells toward CD1d-negative tumor cells remains controversial. Here, we demonstrate that activated iNKT cells recognize leukemia cells in a CD1d-independent manner, however still in a TCR-mediated way. iNKT cells degranulated and released Th1 cytokines toward CD1d-negative leukemia cells (K562, HL-60, REH) as well as αGalCer-loaded CD1d-positive Jurkat cells. The CD1d-independent cytotoxicity was enhanced by natural killer cell-activating receptors such as NKG2D, 2B4, DNAM-1, LFA-1 and CD2, but iNKT cells did not depend on these receptors for the recognition of CD1d-negative leukemia cells. In contrast, TCR was essential for CD1d-independent recognition and cytotoxicity. iNKT cells degranulated toward patient-derived leukemia cells independently of CD1d expression. iNKT cells targeted myeloid malignancies more than acute lymphoblastic leukemia. These findings reveal a novel anti-tumor mechanism of iNKT cells in targeting CD1d-negative tumor cells and indicate the potential of iNKT cells for clinical application to treat leukemia independently of CD1d.
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Antígenos CD1d/metabolismo , Leucemia/inmunología , Leucemia/metabolismo , Activación de Linfocitos/inmunología , Células T Asesinas Naturales/inmunología , Células T Asesinas Naturales/metabolismo , Animales , Antígenos CD1d/genética , Biomarcadores , Degranulación de la Célula , Línea Celular Tumoral , Receptores Coestimuladores e Inhibidores de Linfocitos T/metabolismo , Citocinas/metabolismo , Citotoxicidad Inmunológica , Modelos Animales de Enfermedad , Femenino , Edición Génica , Xenoinjertos , Humanos , Inmunofenotipificación , Leucemia/genética , Leucemia/patología , Activación de Linfocitos/genética , Ratones , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores Gatillantes de la Citotoxidad Natural/metabolismoRESUMEN
Gorlin syndrome (GS) is a hereditary disorder with tumorigenicity, caused by constitutive hyperactivity of hedgehog signaling. Smoothened (SMO) antagonists have been effectively used in the clinical treatment of hedgehog signaling-related cancer. However, these treatments have led to problematic side effects, including severe adverse reactions and drug resistance from additional somatic mutations. We profiled microRNAs in GS fibroblasts to explore a novel therapeutic target for controlling hyper-activated hedgehog signaling. To identify GS-related microRNAs, we analyzed dermal fibroblasts from five patients with GS and three normal controls. We used microarray comparative genomic hybridization to screen 632 human microRNAs in GS fibroblasts. We identified 16 down- and 19 upregulated microRNAs with over twofold change in expression. We validated the increased expression of four microRNAs, confirming hsa-miR-196a-5p downregulation and hsa-miR-4485 upregulation using real-time PCR. Moreover, hsa-miR-196a-5p is complementary to sites in the 3' UTR of MAP3K1, which exhibits upregulated expression at mRNA and protein levels in GS fibroblasts. In addition, hedgehog signal induction with exogenous components decreased miR-196a-5p expression and increased map3k1 expression in a mouse mesenchymal cell line. Given that MAP3K1 has been reported to activate hedgehog signaling, hsa-miR-196a-5p may contribute to the positive feedback loop in this pathway.
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Síndrome del Nevo Basocelular/diagnóstico , Síndrome del Nevo Basocelular/genética , Fibroblastos/metabolismo , Perfilación de la Expresión Génica , MicroARNs/genética , Transcriptoma , Adolescente , Adulto , Animales , Línea Celular , Proliferación Celular , Niño , Hibridación Genómica Comparativa , Biología Computacional/métodos , Femenino , Regulación de la Expresión Génica , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Proteínas Hedgehog/metabolismo , Humanos , Masculino , Ratones , Mutación , Receptor Patched-1/genética , Fenotipo , Estudios Retrospectivos , Transducción de Señal , Adulto JovenRESUMEN
Panton Valentine Leukocidin (PVL) is one of the many toxins produced by Staphylococcus aureus. In Japan, PVL-positive S. aureus strains are mainly methicillin-resistant S. aureus (MRSA). Data regarding PVL-positive methicillin-sensitive S. aureus (MSSA) are scarce. In this report, we describe a case of severe infection by PVL-positive MSSA. A 12-year-old healthy girl was admitted with high fever and pain in the lower back. Computed tomography revealed a diagnosis of psoitis and multiple venous thromboses. Blood cultures obtained after admission revealed infection with MSSA. Her fever continued despite adequate antibiotic therapy. On the fifth hospitalization day, she developed bladder dysfunction, and an abscess was noted near the third lumbar vertebra. She underwent an emergency operation and recovered. Bacterial analyses revealed that the causative MSSA was a PVL-producing single variant of ST8 (related to USA300clone), of sequence type 2149. PVL is known to cause platelet activation. This case demonstrates the need for detailed analyses of the causative strain of bacteria in cases of S. aureus infection with deep vein thrombosis, even in cases of known MSSA infection.
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Toxinas Bacterianas/efectos adversos , Exotoxinas/efectos adversos , Leucocidinas/efectos adversos , Staphylococcus aureus Resistente a Meticilina/patogenicidad , Infecciones Estafilocócicas/complicaciones , Trombosis de la Vena/etiología , Trombosis de la Vena/microbiología , Antibacterianos/uso terapéutico , Niño , Femenino , Humanos , Japón , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/microbiología , Trombosis de la Vena/tratamiento farmacológicoRESUMEN
3M syndrome is an autosomal recessive disease characterized by severe pre-natal and post-natal growth retardation, dysmorphic facial features, and skeletal abnormalities. We present a patient with 3M syndrome caused by the compound heterozygous mutations p.Trp68* and p.Gly1452Asp in CUL7, the latter of which is novel, who exhibited a good body height response to growth hormone treatment. These results expand our knowledge of phenotype-genotype correlations in 3M syndrome, including correlations relevant to growth hormone response.
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Benign hereditary chorea (BHC) is a rare autosomal dominant disease that is characterized by non-progressive chorea with early-childhood-onset, congenital hypothyroidism, and neonatal respiratory distress. Although tetrabenazine and levodopa are partly effective for chorea and drop attacks in some patients, there is no standard treatment option. We herein describe a childhood case of BHC that presented with l-thyroxine-responsive drop attacks. A genetic analysis revealed an interstitial deletion that included two enhancer regions of NKX2-1, providing genetic confirmation of BHC. This is the first report to inform the connection between thyroid function and drop attacks in BHC. Moreover, our findings identify l-thyroxine as a therapeutic option for the management of drop attacks in BHC.
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Antidiscinéticos/uso terapéutico , Corea/tratamiento farmacológico , Síncope/tratamiento farmacológico , Tiroxina/uso terapéutico , Preescolar , Corea/genética , Corea/fisiopatología , Humanos , Masculino , Síncope/genética , Síncope/fisiopatología , Factor Nuclear Tiroideo 1/genéticaRESUMEN
Pallister-Killian syndrome (PKS) is rare genetic disorder caused by tetrasomy 12p mosaicism with supernumerary isochromosome 12p that manifests with intellectual disability, craniofacial dysmorphism, and epilepsy. Although PKS presents as a multisystem morphological defect, respiratory system involvement is rare, except for diaphragmatic hernia. We are the first to report a case of PKS with progressive subglottic stenosis. Subglottic stenosis is a potentially lethal condition due to severe respiratory obstruction and difficult intubation; therefore, further accumulation of cases is required to assess the causal link between PKS and subglottic stenosis.
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Trastornos de los Cromosomas/patología , Anomalías Craneofaciales/patología , Epilepsia/patología , Discapacidad Intelectual/patología , Laringoestenosis/patología , Trastornos de los Cromosomas/diagnóstico por imagen , Trastornos de los Cromosomas/genética , Cromosomas Humanos Par 12/genética , Anomalías Craneofaciales/diagnóstico por imagen , Anomalías Craneofaciales/genética , Progresión de la Enfermedad , Epilepsia/diagnóstico por imagen , Epilepsia/genética , Humanos , Hibridación Fluorescente in Situ , Lactante , Discapacidad Intelectual/diagnóstico por imagen , Discapacidad Intelectual/genética , Cariotipificación , Laringoestenosis/diagnóstico por imagen , Laringoestenosis/genética , Masculino , Tomografía Computarizada por Rayos XRESUMEN
Investigation of cell-cycle kinetics in mammalian pancreatic ß cells has mostly focused on transition from the quiescent (G0) to G1 phase. Here, we report that centromere protein A (CENP-A), which is required for chromosome segregation during the M-phase, is necessary for adaptive ß cell proliferation. Receptor-mediated insulin signaling promotes DNA-binding activity of FoxM1 to regulate expression of CENP-A and polo-like kinase-1 (PLK1) by modulating cyclin-dependent kinase-1/2. CENP-A deposition at the centromere is augmented by PLK1 to promote mitosis, while knocking down CENP-A limits ß cell proliferation and survival. CENP-A deficiency in ß cells leads to impaired adaptive proliferation in response to pregnancy, acute and chronic insulin resistance, and aging in mice. Insulin-stimulated CENP-A/PLK1 protein expression is blunted in islets from patients with type 2 diabetes. These data implicate the insulin-FoxM1/PLK1/CENP-A pathway-regulated mitotic cell-cycle progression as an essential component in the ß cell adaptation to delay and/or prevent progression to diabetes.
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Autoantígenos/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas Cromosómicas no Histona/metabolismo , Proteína Forkhead Box M1/metabolismo , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Transducción de Señal , Animales , Apoptosis , Autoantígenos/genética , Proteínas de Ciclo Celular/genética , Núcleo Celular/metabolismo , Proliferación Celular , Supervivencia Celular , Centrómero/metabolismo , Proteína A Centromérica , Proteínas Cromosómicas no Histona/genética , ADN/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Regulación de la Expresión Génica , Técnicas de Silenciamiento del Gen , Humanos , Ratones Endogámicos C57BL , Ratones Noqueados , Unión Proteica , Proteínas Serina-Treonina Quinasas/genética , Proteínas Proto-Oncogénicas/genética , Receptor de Insulina/metabolismo , Quinasa Tipo Polo 1RESUMEN
Endoplasmic reticulum (ER) stress is among several pathological features that underlie ß-cell failure in the development of type 1 and type 2 diabetes. Adaptor proteins in the insulin/insulin-like-growth factor-1 signaling pathways, such as insulin receptor substrate-1 (IRS1) and IRS2, differentially impact ß-cell survival but the underlying mechanisms remain unclear. Here we report that ß-cells deficient in IRS1 (IRS1KO) are resistant, while IRS2 deficiency (IRS2KO) makes them susceptible to ER stress-mediated apoptosis. IRS1KOs exhibited low nuclear accumulation of spliced XBP-1 due to its poor stability, in contrast to elevated accumulation in IRS2KO. The reduced nuclear accumulation in IRS1KO was due to protein instability of Xbp1 secondary to proteasomal degradation. IRS1KO also demonstrated an attenuation in their general translation status in response to ER stress revealed by polyribosomal profiling. Phosphorylation of eEF2 was dramatically increased in IRS1KO enabling the ß-cells to adapt to ER stress by blocking translation. Furthermore, significantly high ER calcium (Ca(2+)) was detected in IRS1KO ß-cells even upon induction of ER stress. These observations suggest that IRS1 could be a therapeutic target for ß-cell protection against ER stress-mediated cell death by modulating XBP-1 stability, protein synthesis, and Ca(2+) storage in the ER.