37 research outputs found

    Neonatal overnutrition increases testicular size and expression of luteinizing hormone ß-subunit in peripubertal male rats

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    Proper nutrition is important for growth and development. Maturation of the reproductive axis and the timing of pubertal onset can be delayed when insufficient nutrition is available, or possibly advanced with nutritional abundance. The childhood obesity epidemic has been linked to a secular trend in advanced puberty in some populations. The increase in circulating leptin that occurs in association with obesity has been suggested to act as a signal that an adequate nutritional status exists for puberty to occur, allowing activation of central mechanisms. However, obesity-associated hyperleptinemia is linked to decreased leptin sensitivity, at least in adults. Here, we analyzed whether neonatal overnutrition modifies the response to an increase in leptin in peripubertal male rats, as previously demonstrated in females. Wistar rats were raised in litters of 4 (neonatal overnutrition) or 12 pups (controls) per dam. Leptin was administered sc (3 μg/g body weight) at postnatal day 35 and the rats killed 45 min or 2 h later. Postnatal overfeeding resulted in increased body weight and circulating leptin levels; however, we found no overweight-related changes in the mRNA levels of neuropeptides involved in metabolism or reproduction. In contrast, pituitary expression of luteinizing hormone (LH) beta-subunit was increased in overweight rats, as was testicular weight. There were no basal differences between L4 and L12 males or in their response to leptin administration in pSTAT3 levels in the hypothalamus at either 45 min or 2 h. In contrast, pJAK2 was found to be higher at 45 min in L4 compared to L12 males regardless of leptin treatment, while at 2 h it was higher in L4 leptin-treated males compared to L12 leptin-treated males, as well as L4 vehicle-treated rats. There were no changes in response to leptin administration in the expression of the neuropeptides analyzed. However, serum LH levels rose only in L4 males in response to leptin, but with no change in testosterone levels. In conclusion, the advancement in pubertal onset in males with neonatal overnutrition does not appear to be related to overt modifications in the central response to exogenous leptin during the peripubertal periodThe authors are funded by Fondos de Investigación Sanitaria (PI1600485 to JA), Ministerio de Ciencia e Innovación (BFU2014-51836-C2-2-R and BFU2017-82565-C2-1-R to JC) and fondos FEDER, Centro de Investigación Biomédica en Red Fisiopatología de Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (JA), and Fundación Endocrinología y Nutrició

    A proteomic approach to obesity and type 2 diabetes

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    The incidence of obesity and type diabetes 2 has increased dramatically resulting in an increased interest in its biomedical relevance. However, the mechanisms that trigger the development of diabetes type 2 in obese patients remain largely unknown. Scientific, clinical and pharmaceutical communities are dedicating vast resources to unravel this issue by applying different omics tools. During the last decade, the advances in proteomic approaches and the Human Proteome Organization have opened and are opening a new door that may be helpful in the identification of patients at risk and to improve current therapies. Here, we briefly review some of the advances in our understanding of type 2 diabetes that have occurred through the application of proteomics. We also review, in detail, the current improvements in proteomic methodologies and new strategies that could be employed to further advance our understanding of this pathology. By applying these new proteomic advances, novel therapeutic and/or diagnostic protein targets will be discovered in the obesity/Type 2 diabetes areaThis work is funded by Ministerio de Ciencia e Innovación (BFU2011–27492), Fondos de Investigación Sanitaria (PI1302195), Centro de Investigación Biomédica en Red Fisiopatología de Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III and Fundación de Endocrinología y Nutrición. Dr. Elena López Villar is supported by ISCIII Spanish Health System (SNS BOE 2012) and she is Delegate of HUPO (Human Proteome Organization) supporting clinical proteomic studies at Hospital Niño Jesús of Madrid, Spain, to improve diagnosis and therapies via researc

    Challenges and improvement needs in the care of patients with central diabetes insipidus

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    Central diabetes insipidus (CDI) is a rare condition, with significant impact on patient health and well-being. It is a chronic condition which usually requires meticulous long-term care. It can affect both children and adults. There is limited literature considering the needs and challenges inherent in providing high quality care to patients with CDI, across the care pathway. This paper seeks to address this gap by providing a unique and well-rounded understanding of clinical and healthcare systems-related challenges. It draws on insights from the literature, from direct clinical experience contributed by five clinicians as co-authors (providing insights from France, Ireland, Italy, Spain and the United Kingdom), and from patient perspectives provided through interviews with patient representatives from three patient organisations. We identify clinical challenges related to the diagnosis of CDI, including differentiating between other similar conditions and determining the underlying aetiology. Treatment is challenging, given the need to tailor medication to each patient’s needs and ongoing management is required to ensure that patients continue to respond adequately to treatment. Ongoing support is required when patients switch between formulations. We also identify healthcare systems challenges related to limited awareness of CDI amongst primary care physicians and general paediatricians, and the need for highly skilled specialist care and appropriate workforce capacity. There is also a significant need for raising awareness and for the education of both healthcare professionals and patients about different aspects of CDI, with the aim of supporting improved care and effective patient engagement with healthcare professionals. We reflect on this information and highlight improvement opportunities. These relate to developing guidance to support patients, carers, primary care physicians and general paediatricians to identify clinical features earlier, and to consider CDI as a possible diagnosis when a patient presents with suggestive symptom

    Natural course of septo-optic dysplasia: Retrospective analysis of 20 cases

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    Introducción. La displasia septoóptica (DSO) es la combinación variable de signos de disgenesia de línea media cerebral, hipoplasia de nervios ópticos y disfunción hipotálamo-hipofisaria, asociándose, a veces, con un espectro variado de malformaciones de la corteza cerebral. Objetivo. Describir la evolución natural y los hallazgos de neuroimagen en una serie de 20 pacientes diagnosticados. Pacientes y métodos. Se revisan de forma retrospectiva las características epidemiológicas, clínicas y neurroradiológicas de 20 pacientes consecutivos diagnosticados de DSO entre enero de 1985 y enero de 2010. Se analizaron los datos de tomografía computarizada, resonancia magnética craneal, electroencefalograma, potenciales evocados visuales, valoración oftalmológica, cariotipo y estudio endocrinológico. En siete pacientes, se realizó estudio del gen Homeobox HESX1. Resultados. El 60% de los casos presentaba antecedentes patológicos en el primer trimestre de gestación, con las ecografías fetales normales. Clínicamente, destacaban manifestaciones visuales (85%), alteraciones endocrinas (50%), retraso mental (60%) y crisis epilépticas (55%). Un 55% se asociaba a anomalías de migración neuronal. En un 45%, la DSO era el único hallazgo de neuroimagen. Se realizó cariotipo a todos, siendo normal. El gen HESX1 fue positivo en dos de los siete casos estudiados (ambos con DSO aislada). Ninguno con mutación en el gen HESX1 presentaba consanguinidad familiar. No se realizó estudio genético a los padres. Conclusiones. La DSO debe clasificarse como un síndrome malformativo heterogéneo, que asocia múltiples anomalías cerebrales, oculares, endocrinas y sistémicas. Las formas más graves se asocian con anomalías de la migración neuronal y de la organización cortical (AU)Introduction. Septo-optic dysplasia (SOD) is the variable combination of signs of dysgenesis of the midline of the brain, hypoplasia of the optic nerves and hypothalamus-pituitary dysfunction, which is sometimes associated with a varied spectrum of malformations of the cerebral cortex. Aims. To describe the natural history and neuroimaging findings in a series of 20 diagnosed patients. Patients and methods. We review the epidemiological, clinical and neuroimaging characteristics of 20 consecutive patients diagnosed with SOD between January 1985 and January 2010. Data obtained from computerised tomography, magnetic resonance imaging of the head, electroencephalogram, visual evoked potentials, ophthalmological evaluation, karyotyping and endocrinological studies were analysed. In seven patients, a study of the gene Homeobox HESX1 was conducted. Results. Pathological antecedents in the first three months of gestation were presented by 60% of the cases, with normal results in the foetal ultrasound scans. Clinically, the most striking features were visual manifestations (85%), endocrine disorders (50%), mental retardation (60%) and epileptic seizures (55%). Fifty-five per cent were associated to abnormal neuronal migration. In 45%, SOD was the only finding in the neuroimaging scans. Karyotyping was performed in all cases, the results being normal. Gene HESX1 was positive in two of the seven cases studied (both with isolated SOD). None of those with mutation in gene HESX1 presented familial consanguinity. No gene study was conducted with the parents. Conclusions. SOD must be classified as a heterogeneous malformation syndrome, which is associated to multiple brain, ocular, endocrine and systemic anomalies. The most severe forms are associated with abnormal neuronal migration and cortical organisation (AU

    Proteomic analysis allows for early detection of potential markers of metabolic impairment in very young obese children

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    BACKGROUND: Early diagnosis of initial metabolic derangements in young obese children could influence their management; however, this impairment is frequently not overt, but subtle and undetectable by routinely used clinical assays. Our aim was to evaluate the ability of serum proteomic analysis to detect these incipient metabolic alterations in comparison to standard clinical methods and to identify new candidate biomarkers. METHODS: A cross-sectional study of fasting serum samples from twenty-two prepubertal, Caucasian obese (OB; 9.22 ± 1.93 years; 3.43 ± 1.08 BMI-SDS) and twenty-one lean controls (C; 8.50 ± 1.98 years; -0.48 ± 0.81 BMI-SDS) and a prospective study of fasting serum samples from twenty prepubertal, Caucasian obese children (11 insulin resistant [IR]) before (4.77 ± 1.30 BMI-SDS) and after weight reduction (2.57 ± 1.29 BMI-SDS) by conservative treatment in a reference hospital (Pros-OB) was performed. Proteomic analysis (two-dimension-eletrophoresis + mass spectrometry analysis) of serum and comparative evaluation of the sensitivity of routinely used assays in the clinics to detect the observed differences in protein expression level, as well as their relationship with anthropometric features, insulin resistance indexes, lipid profile and adipokine levels were carried out. RESULTS: Study of the intensity data from proteomic analysis showed a decrease of several isoforms of apolipoprotein-A1, apo-J/clusterin, vitamin D binding protein, transthyretin in OBvs. C, with some changes in these proteins being enhanced by IR and partially reversed after weight loss. Expression of low molecular weight isoforms of haptoglobin was increased in OB, enhanced in IR and again decreased after weight loss, being positively correlated with serum interleukin-6 and NAMPT/visfatin levels. After statistical correction for multiple comparisons, significance remained for a single isoform of low MW haptoglobin (OB vs. C and IR vs. non-IR) and Apo A1 (IR vs. non-IR). Assays routinely used in the clinical setting (ELISA/kinetic nephelometry), only partially confirmed the changes observed by proteomic analysis (ApoA1 and haptoglobin). CONCLUSION: Proteomic analysis can allow for the identification of potential new candidate biomarkers as a complement to routinely used assays to detect initial changes in serum markers of inflammation and lipid metabolism impairment in young obese children

    Defective minor spliceosome mRNA processing results in isolated familial growth hormone deficiency

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    The molecular basis of a significant number of cases of isolated growth hormone deficiency remains unknown. We describe three sisters affected with severe isolated growth hormone deficiency and pituitary hypoplasia caused by biallelic mutations in the RNPC3 gene, which codes for a minor spliceosome protein required for U11/U12 small nuclear ribonucleoprotein (snRNP) formation and splicing of U12-type introns. We found anomalies in U11/U12 di-snRNP formation and in splicing of multiple U12-type introns in patient cells. Defective transcripts include preprohormone convertases SPCS2 and SPCS3 and actin-related ARPC5L genes, which are candidates for the somatotroph-restricted dysfunction. The reported novel mechanism for familial growth hormone deficiency demonstrates that general mRNA processing defects of the minor spliceosome can lead to very narrow tissue-specific consequences.Peer reviewe

    Functional Characterization of MODY2 Mutations Highlights the Importance of the Fine-Tuning of Glucokinase and Its Role in Glucose Sensing

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    Glucokinase (GK) acts as a glucose sensor in the pancreatic beta-cell and regulates insulin secretion. Heterozygous mutations in the human GK-encoding GCK gene that reduce the activity index increase the glucose-stimulated insulin secretion threshold and cause familial, mild fasting hyperglycaemia, also known as Maturity Onset Diabetes of the Young type 2 (MODY2). Here we describe the biochemical characterization of five missense GK mutations: p.Ile130Thr, p.Asp205His, p.Gly223Ser, p.His416Arg and p.Ala449Thr. The enzymatic analysis of the corresponding bacterially expressed GST-GK mutant proteins show that all of them impair the kinetic characteristics of the enzyme. In keeping with their position within the protein, mutations p.Ile130Thr, p.Asp205His, p.Gly223Ser, and p.His416Arg strongly decrease the activity index of GK, affecting to one or more kinetic parameters. In contrast, the p.Ala449Thr mutation, which is located in the allosteric activator site, does not affect significantly the activity index of GK, but dramatically modifies the main kinetic parameters responsible for the function of this enzyme as a glucose sensor. The reduced Kcat of the mutant (3.21±0.28 s−1 vs 47.86±2.78 s−1) is balanced by an increased glucose affinity (S0.5 = 1.33±0.08 mM vs 7.86±0.09 mM) and loss of cooperativity for this substrate. We further studied the mechanism by which this mutation impaired GK kinetics by measuring the differential effects of several competitive inhibitors and one allosteric activator on the mutant protein. Our results suggest that this mutation alters the equilibrium between the conformational states of glucokinase and highlights the importance of the fine-tuning of GK and its role in glucose sensing

    Pathogenic variants in SLF2 and SMC5 cause segmented chromosomes and mosaic variegated hyperploidy

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    Embryonic development is dictated by tight regulation of DNA replication, cell division and differentiation. Mutations in DNA repair and replication genes disrupt this equilibrium, giving rise to neurodevelopmental disease characterized by microcephaly, short stature and chromosomal breakage. Here, we identify biallelic variants in two components of the RAD18-SLF1/2-SMC5/6 genome stability pathway, SLF2 and SMC5, in 11 patients with microcephaly, short stature, cardiac abnormalities and anemia. Patient-derived cells exhibit a unique chromosomal instability phenotype consisting of segmented and dicentric chromosomes with mosaic variegated hyperploidy. To signify the importance of these segmented chromosomes, we have named this disorder Atelís (meaning - incomplete) Syndrome. Analysis of Atelís Syndrome cells reveals elevated levels of replication stress, partly due to a reduced ability to replicate through G-quadruplex DNA structures, and also loss of sister chromatid cohesion. Together, these data strengthen the functional link between SLF2 and the SMC5/6 complex, highlighting a distinct role for this pathway in maintaining genome stability

    Fifteen years of research on oral–facial–digital syndromes: from 1 to 16 causal genes

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    Oral–facial–digital syndromes (OFDS) gather rare genetic disorders characterised by facial, oral and digital abnormalities associated with a wide range of additional features (polycystic kidney disease, cerebral malformations and several others) to delineate a growing list of OFDS subtypes. The most frequent, OFD type I, is caused by a heterozygous mutation in the OFD1 gene encoding a centrosomal protein. The wide clinical heterogeneity of OFDS suggests the involvement of other ciliary genes. For 15 years, we have aimed to identify the molecular bases of OFDS. This effort has been greatly helped by the recent development of whole-exome sequencing (WES). Here, we present all our published and unpublished results for WES in 24 cases with OFDS. We identified causal variants in five new genes (C2CD3, TMEM107, INTU, KIAA0753 and IFT57) and related the clinical spectrum of four genes in other ciliopathies (C5orf42, TMEM138, TMEM231 and WDPCP) to OFDS. Mutations were also detected in two genes previously implicated in OFDS. Functional studies revealed the involvement of centriole elongation, transition zone and intraflagellar transport defects in OFDS, thus characterising three ciliary protein modules: the complex KIAA0753-FOPNL-OFD1, a regulator of centriole elongation; the Meckel-Gruber syndrome module, a major component of the transition zone; and the CPLANE complex necessary for IFT-A assembly. OFDS now appear to be a distinct subgroup of ciliopathies with wide heterogeneity, which makes the initial classification obsolete. A clinical classification restricted to the three frequent/well-delineated subtypes could be proposed, and for patients who do not fit one of these three main subtypes, a further classification could be based on the genotype
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