Growth hormone receptor gene polymorphism. Spontaneous catch up growth in small for gestational age patients / Polimorfismo del gen del receptor de la hormona de crecimiento. Crecimiento postnatal espontáneo en niños pequeños para la edad gestacional

Abstract The growth hormone receptor (GHR) mediates the effect of growth hormone (GH) on linear growth and metabolism. In humans, it exists as two isoforms differing by the retention or exclusion of exon 3; a full-length GHR isoform (GHRfl) and the exon 3-deleted isoform (GHRd3). The genotypic frequency of this polymorphism was analyzed in several studies and in different human populations. However scarce information in Argentinean population is available. Associations between GHRd3 and growth have been reported previously. Some studies have shown that the presence of GHRd3 polymorphism might be a potential variant that improves growth response to recombinant human GH (rhGH) therapy in patients born small for gestational age (SGA), among others. However, over the years the results have been controversial and inconclusive. Based on this, it would be proposed that variants at the genomic level are not completely reflected at the mRNA level. Our aim was to evaluate the genotypic frequencies (%) of the GHR gene polymorphism (GHRfl/GHRfl; GHRfl/GHRd3; GHRd3/GHRd3) in normal Argentinean population (n = 94) and SGA patients (n = 65), and the expression of these polymorphisms at mRNA level in the fetal side of placenta tissues was analyzed. In addition, their asso ciation with spontaneous postnatal catch-up growth in SGA patients was also evaluated. In this study, we show a significant increment of compensatory growth in small for gestational age children (SGA) associated to the presence of the GHRd3 allele polymorphism. In addition, the expression of GHR in healthy placentas revealed that no alternative splicing mechanism occurs.

Resumen El receptor de la hormona de creci miento (GHR) media la acción de la hormona de crecimiento (GH) en el crecimiento lineal y el metabolismo. En los seres humanos, existen dos isoformas que difieren en la retención (GHRfl) o exclusión del exón 3 (GHRd3). La frecuencia genotípica de este polimorfismo fue analizada en varios estudios y en diferentes poblaciones. Sin embargo, la información disponible en la población argentina es escasa. Se ha reportado anteriormente asociación entre el polimorfismo GHRd3 y el crecimiento. Varios estudios ha n demostrado que la presencia del polimorfismo GHRd3 podría mejorar, en pacientes nacidos pequeños para la edad gestacional, entre otros, la respuesta a la terapia con GH humana recombinante (rhGH). Sin embargo, a lo largo de los años los resultados han sido con trovertidos y no concluyentes. En base a esto, se propondría que las variantes a nivel genómico no se reflejan completamente a nivel del ARNm. Nuestro objetivo fue evaluar la frecuencia genotípica de los polimorfismos del gen del GHR (GHRfl/GHRfl; GHRfl/GHRd3; GHRd3/GHRd3) en la población argentina normal (n = 94) y en niños pequeños para la edad gestacional (n = 65), y se analizó la expresión de estos polimorfismos a nivel de ARNm en la porción fetal de placentas sanas. Además, se evaluó la asociación de este polimorfismo con el cre cimiento postnatal espontáneo en pacientes pequeños para la edad gestacional. En este estudio, mostramos un incremento significativo del crecimiento compensatorio en niños pequeños para la edad gestacional asociado a la presencia del polimorfismo del alelo GHRd3. Además, los ensayos de expresión de GHR en placentas sanas revelaron que no se produciría ningún mecanismo de splicing alternativo.

Expressão gênica de IGF-I e GHR no fígado e no músculo do peito de codornas de corte suplementadas com diferentes níveis de metionina em duas gerações sucessivas / IGF-I and GHR gene expression in liver and breast muscle of meat quails supplemented with different levels of methionine in two successive generations

Este estudo foi desenvolvido com o objetivo de avaliar a expressão gênica do fator de crescimento semelhante à insulina I (IGF-I) e do receptor do hormônio do crescimento (GHR) no fígado e no músculo do peito de codornas de corte, alimentadas com dietas contendo diferentes níveis de suplementação de metionina, em duas gerações sucessivas. Foram utilizadas codornas dos 22 aos 42 dias de idade, distribuídas em três e cinco tratamentos na primeira e na segunda geração, respectivamente. Ao final, as aves foram abatidas por deslocamento cervical, sendo coletados fígado e músculo do peito para extração de RNA total. O cDNA foi amplificado usando primers específicos para os genes analisados. Os resultados mostraram que a expressão dos genes GHR e IGF-I sofreu influência da suplementação. No quinto tratamento, em que apenas a primeira geração recebeu uma suplementação acima do padrão das exigências para o período, houve uma expressão significativamente maior do GHR tanto no músculo do peito como no fígado e igualmente do IGF-I no músculo, levando a concluir que o excesso de metionina na dieta torna-se tóxica para as aves. Apesar de a expressão dos genes ter sofrido influência da adição de metionina nos níveis estudados, não foi observada diferença no consumo alimentar, na conversão alimentar e no peso das aves.(AU)

This study was conducted to evaluate the gene expression of the insulin-like I growth factor (IGF-I) and growth hormone receptor (GHR), in the liver and chest muscle of slaughter quails fed with diets containing different levels of methionine supplementation, in two successive generations. Twenty-two to 42 day-old quails were used, distributed in three and five treatments in the first and second generation, respectively. At the end, the birds were killed by cervical dislocation, and their liver and chest muscle were collected for total RNA extraction. The cDNA was amplified using specific primers for the genes analyzed. The results showed that the expression of GHR gene and IGF-I were influenced by the supplementation. In the fifth treatment, where only the first generation received supplementation above the standard requirements for the period, there was a significantly higher expression of GHR both in muscle chest and in the liver, and also IGF-I on muscle, leading to the conclusion that the excess dietary methionine becomes toxic to birds. Despite the gene´s expression seeming to be influenced by the addition of methionine levels in the study, there was no difference in feed intake, feed conversion and weight of the birds.(AU)

Fatores ambientais associados ao tempo de decisão para procura de atendimento no infarto do miocárdio / Environmental factors associated with the decision time for seeking care in myocardial infarction / Factores ambientales asociados con el tiempo de decisión para la búsqueda de atención en el infarto de miocardio

Objetivou-se estimar o tempo de decisão para procura de atendimento (TD) para homens e mulheres com infarto agudo do miocárdio (IAM); analisar a influência de variáveis ambientais no TD e a interação entre gênero e variáveis ambientais para o desfecho TD. Estudo transversal, envolvendo cem pacientes, entrevistados em hospitais de Salvador. Na análise dos dados empregou-se o Qui-quadrado ou Exato de Fisher e o Modelo de Regressão Linear Robusto. Predominou o IAM ocorrido no domicílio, familiares no entorno, e os pacientes sendo alvo de ações equivocadas. Observou-se TD elevado para mulheres (0,9h) e homens (1,4h). Aqueles em casa no início dos sintomas tiveram maior TD, comparados aos no trabalho e menor em relação aos em via pública (p=0,047). Houve interação estatisticamente significante entre gênero e viver acompanhado; e entre gênero e ter companheiro e filhos no entorno, para o desfecho TD. O cuidar em enfermagem focalizado nas especificidades de fatores ambientais e de gênero pode otimizar o atendimento precoce.

The purpose was to estimate the decision time (DT) for searching for attendance for men and women suffering from acute myocardial infarction (AMI); and to analyze the influence of surrounding variables in the DT. Transversal study, involving one hundred patients interviewed in hospitals of Salvador-BA, Brazil. For data analysis, it was used the chi-squared or Fisher’s exact test, and the Robust Linear Regression Model. AMI at the home predominated, with family members and patients receiving mistaken actions. A high DT was observed both, for women (0.9h) and men (1.4h). Those at home during the initial symptoms had higher DT, compared to those at work; and lower in relation to those in public spaces (p=0.047). Statistically significant interaction occurred among gender and the fact of living with company; and among gender and having a companion and children, for the outcome of the DT. Nursing care focused on the specificity of surrounding factors and gender can optimize early attendance.

Se objetivó estimar el tiempo de decisión para buscar atendimiento (TD) para hombres y mujeres con infarto agudo de miocardio (IAM); analizar la influencia de variables ambientales en TD y la interacción entre genero y variables ambientales para el desfecho del TD. Estudio transversal, envolviendo cien pacientes entrevistados en hospitales de Salvador-BA, Brasil. En el análisis se utilizó el chi-cuadrado o el Teste Exacto de Fisher y el Modelo de Regresión Linear Robusto. Predominó el IAM en el domicilio, familiares en el entorno y con pacientes siendo objeto de acciones equivocadas. Se observó TD elevados para mujeres (0,9h) y hombres (1,4h). Aquellos en sus casas en el inicio de los síntomas tuvieron mayor TD, comparados a los en el trabajo, y menor en relación aquellos en vía pública (p=0,047). Hubo interacción estadísticamente significante entre genero y vivir acompañado y entre genero y tener compañero e hijos en el entorno, para el desfecho del TD. El cuidar en enfermería focalizado en especificidades de factores ambientales y de géneros puede optimizar el atendimiento precoce.

Single-nucleotide polymorphism analysis of GH, GHR, and IGF-1 genes in minipigs

Tibetan (TB) and Bama (BM) miniature pigs are two popular pig breeds that are used as experimental animals in China due to their small body size. Here, we analyzed single-nucleotide polymorphisms (SNPs) in gene fragments that are closely related to growth traits [growth hormone (GH), growth hormone receptor (GHR), and insulin-like growth factor (IGF)-1)] in these pig breeds and a large white (LW) control pig breed. On the basis of the analysis of 100 BMs, 108 TBs, and 50 LWs, the polymorphic distribution levels of GH, GHR, and IGF-1 were significantly different among these three pig breeds. According to correlation analyses between SNPs and five growth traits - body weight (BW), body length (BL), withers height (WH), chest circumference (CC), and abdomen circumference (AC) - three SNP loci in BMs and four SNP loci in TBs significantly affected growth traits. Three SNP sites in BMs and four SNP sites in TBs significantly affected growth traits. SNPs located in the GH gene fragment significantly affected BL and CC at locus 12 and BL at locus 45 in BMs, and also BW, WH, CC, and AC at locus 45 and WH and CC at locus 93 in TBs. One SNP at locus 85 in the BM GHR gene fragment significantly affected all growth traits. All indices were significantly reduced with a mixture of alleles at locus 85. These results provide more information regarding the genetic background of these minipig species and indicate useful selection markers for pig breeding programs.

Growth hormone receptor inhibition decreases the growth and metastasis of pancreatic ductal adenocarcinoma

Pancreatic cancer is the only major cancer with very low survival rates (1%). It is the fourth leading cause of cancer-related death. Hyperactivated growth hormone receptor (GHR) levels have been shown to increase the risk of cancer in general and this pathway is a master regulator of key cellular functions like proliferation, apoptosis, differentiation, metastasis, etc. However, to date there is no available data on how GHR promotes pancreatic cancer pathogenesis. Here, we used an RNA interference approach targeted to GHR to determine whether targeting GHR is an effective method for controlling pancreatic cancer growth and metastasis. For this, we used an in vitro model system consisting of HPAC and PANC-1 pancreatic cancer cells lines. GHR is upregulated in both of these cell lines and silencing GHR significantly reduced cell proliferation and viability. Inhibition of GHR also reduced the metastatic potential of pancreatic cancer cells, which was aided through decreased colony-forming ability and reduced invasiveness. Flow cytometric and western blot analyses revealed the induction of apoptosis in GHR silenced cells. GHR silencing affected phosphatidylinositol 3 kinase/AKT, mitogen extracellular signal-regulated kinase/extracellular signal-regulated kinase, Janus kinase/signal transducers and activators of transcription and mammalian target of rapamycin signaling, as well as, epithelial to mesenchymal transition. Interestingly, silencing GHR also suppressed the expression of insulin receptor-beta and cyclo-oxygenease-2. Altogether, GHR silencing controls the growth and metastasis of pancreatic cancer and reveals its importance in pancreatic cancer pathogenesis.

Polimorfismo GHRd3 e suas implicações na prática clínica / GHRd3 polymorphisms and their implications in clinical practice

O hormônio do crescimento (GH), ou somatotropina, é um hormônio secretado pela glândula hipófise anterior, cuja função é promover e controlar o crescimento corporal. Polimorfismos em receptores de hormônios têm sido apontados como importantes no desenvolvimento de muitas doenças e, entre os polimorfismos do gene GHR, o polimorfismo representado pela deleção do éxon 3 do gene GHR (GHRd3) tem sido o mais estudado. Este polimorfismo tem influência sobre a expressão e/ou responsividade do GHR, afetando sua ligação ao GH. O objetivo deste trabalho é realizar uma revisão sobre o polimorfismo GHRd3 e suas implicações na prática clínica

Growth hormone (GH) or somatotropin is a hormone secreted by the anterior pituitary gland, whose function is to promote and control the body growth. Polymorphisms in hormone receptors have been identified as important in the development of many diseases, and, among the GHR gene polymorphisms, the polymorphism represented by the deletion of exon 3 of the GHR gene (GHRd3) has been the most studied. This polymorphism influences the expression and/or responsiveness of GHR, affecting its binding to GH. The aim of this study is to perform a review of GHRd3 polymorphism and its implications for clinical practice

Asociación de la variante GHRd3 del receptor de la hormona de crecimiento con autoinmunidad en la diabetes tipo 1 / Association of GHRd3 variant of growth hormone receptor gene with autoimmunity in type 1 diabetes

Background: Growth Hormone Receptor (GRH) is expressed in the liver, pancreas, stomach and small intestine. A high expression of GHR mRNA in the mucosal gut suggests a possible role of this receptor on digestive and immune functions. Aim: To investigate the putative effects of the GHRd3 variants on the cytokine profile and distribution of auto-antibodies in children with type 1 diabetes (T1D). Material and Methods: Unrelated unaffected controls (n =192) and incident cases of children with T1D (n =127) were analyzed for GHRd3 polymorphism, cytokine profile and a panel of auto-antibodies. Results: The allele frequency for d3 was 24.8 percent in type 1 diabetics and 34.1 percent in controls (p =NS). Among type 1 diabetic children, the carriers of the GHRd3 polymorphism had significantly higher levels of interleukin-lB than homozygous for the wild type genotype (5.7 and 17.7, pg/ml respectively p <0.015). Carriers of d3 variant had a higher frequency of positive anti-insulin antibodies (anti-IAA) than children without this variant (39.6 and 17.7 percent respectively, p <0.01). Conclusions: The observed frequency of the GHR d3/d3 genotype was comparable to other reports. A relationship between d3 variant and anti-IAA antibodies and interleukin-1ß was observed.

Investigação de baixa estatura: aspectos clínicos, laboratoriais e moleculares da insensibilidade ao hormônio de crescimento / Short stature investigation: clinical, laboratorial and genetic aspects concerning the trowth hormone insensitivity (GHI)

Neste artigo são descritos os aspectos clínicos, laboratoriais e genéticos da investigação da baixa estatura, dando ênfase para o diagnóstico da insensibilidade ao hormônio de crescimento (IGH). O paciente apresentado possuía características clínicas típicas de pacientes com IGH e em idade pré-púbere seus achados laboratoriais eram compatíveis com este diagnóstico (IGF-1 e IGFBP3 baixos, GH basal e pós-estímulo elevados). No entanto, quando avaliado durante a puberdade, as dosagens de IGF-1 e IGFBP-3 foram normais, dificultando o diagnóstico. O estudo molecular identificou mutação no exon 7 do gene do receptor do hormônio de crescimento (S226I). Discutiram-se os passos realizados para identificar a mutação e demonstrar que ela é responsável pelo fenótipo observado no paciente. Também será feita revisão dos casos de IGH descritos no Brasil e dos novos defeitos moleculares descritos nesta doença.

It is reported in this study the clinical, laboratory and genetic aspects of short stature investigation with emphasis to the diagnostic approach of growth hormone insensitivity (GHI). This patient in case presented typical clinical features of GHI and his laboratory findings at prepubertal age were typical of those observed in GHI patients (low IGF-1 and IGFBP-3 levels, with high basal and stimulated GH levels). However, during the puberty, he presented normal IGFBP-3 and IGF-1 levels that hindered the diagnosis. The molecular study disclosed a mutation in exon 7 of growth hormone receptor gene (S226I). The steps that demonstrated the causative effect of this mutation are shown here, and also a review of Brazilian GHI cases is given and new molecular defects in this field are discussed as well.

Efeito fundador da mutação E180splice no gene do receptor de hormônio de crescimento identificada em pacientes brasileiros com insensibilidade ao GH / Founder effect of E180splice mutation in growth hormone receptor gene (GHR) identified in brazilian patients cith GH insensitivity

Estudamos o gene do receptor de hormônio de crescimento (GHR) de 6 pacientes com síndrome de Laron (SL) provenientes de 4 famílias distintas. Os exons 2 a 10 foram amplificados por pares de primers intrônicos. Os produtos de PCR foram seqüenciados diretamente. Os 6 pacientes possuíam no exon 6, codon 180, a troca GGA>GAA em homozigose. Esta mutação não altera o aminoácido traduzido, porém cria um novo sítio de splice que causa a deleção de 8 aminoácidos do domínio extracelular do GHR. Para avaliar um efeito fundador da mutação E180splice, os membros das 4 famílias foram genotipados para 4 regiões intragênicas polimórficas: a presença ou ausência do exon 3, dois polimorfismos de um único nucleotídeo presentes nos exons 6 e 10 e o sítio polimórfico no intron 9. Todos os pacientes apresentavam o mesmo haplótipo destas 4 regiões. A mutação E180splice foi descrita anteriormente em uma comunidade andina no sul do Equador descendente de espanhóis e também numa família judia de Israel. Nossas famílias compartilham o mesmo haplótipo do intron 9 observado nestes pacientes. Concluímos que a mutação E180splice é uma importante causa de IGH no Brasil e a presença do mesmo haplótipo em nossos pacientes, nos pacientes equatorianos e israelenses com a mutação E180splice é forte indício do efeito fundador desta mutação.

Molecular defects in the growth hormone-IGF axis.

Many previously uncharacterized cases of poor growth in children, i.e. idiopathic short stature, are now attributable to genetic defects in the GH-IGF-1 axis. This paper will provide an overview of the clinical findings of patients identified with various genetic defects of the GH/IGF-1 axis with an emphasis on the more recently described syndromes.