New insights of growth hormone (GH) actions from tissue-specific GH receptor knockouts in mice

ABSTRACT In order to provide new insights into the various activities of GH in specific tissues, recent advances have allowed for the generation of tissue-specific GHR knockout mice. To date, 21 distinct tissue-specific mouse lines have been created and reported in 28 publications. Targeted tissues include liver, muscle, fat, brain, bone, heart, intestine, macrophage, pancreatic beta cells, hematopoietic stem cells, and multi-tissue "global". In this review, we provide a brief history and description of the 21 tissue-specific GHR knockout mouse lines. Arch Endocrinol Metab. 2019;63(6):557-67

Polimorfismos del receptor de GH en pacientes acromegálicos / GH Receptor Polymorphisms in Acromegalic Patients

El receptor de la hormona de crecimiento (GHR) (hormona de crecimiento. media los efectos de GH. Se identificaron varias isoformas de dicho receptor, producto de polimorfismos en las secuencias codificantes del gen del GHR. La isoforma (d3-GHR) carece de una secuencia de 22 aminoácidos codificada por el exón 3, y si bien su capacidad de unión al ligando se mantiene intacta, afectaría las propiedades funcionales del GHR, y podría facilitar la activación del GHR. Se observó que el 50 % de los pacientes acromegálicos tienen al menos un alelo d3. Se reportó que el alelo d3 contribuyó como predictor de respuesta posquirúrgica con niveles significativamente menores de hormona de crecimiento (GH) a diferencia de los fl-GHR (forma completa), con similares niveles de IGF-1 (insulin-likegrowth factor 1). La ausencia del exón 3 se asoció además con mayor probabilidad de no alcanzar IGF-I normal después del tratamiento tanto quirúrgico como médico. Los portadores d3-GHR se asocian con menor dosis requerida de PEG (Pegvisomant), siendo el mecanismo de esta mayor sensibilidad desconocido. Estos pacientes también podrían tener mayor prevalencia de comorbilidades acromegálicas. Estos estudios demuestran la importancia del genotipo del GHR, no solo como variable predictora de evolución clínica, sino que su evaluación podría ser útil para individualizar la terapia óptima en cada paciente.

The growth hormone receptor mediates the effects of GH. Several isoforms of this receptor, as a product of polymorphisms in the coding sequences of GHR gene, have been identified. The d3-GHR isoform lacks a 22-amino-acid sequence encoded by exon 3, and although its ligand binding capacity remains intact, its deletion would affect the functional properties of GHR, and could facilitate the activation of the GHR. It has been reported that 50 % of acromegalic patients have at least one d3 allele. The d3 allele has been shown to contribute to predict postoperative response presenting significantly lower levels of GH in contrast to fl-GHR (full-length), with similar levels of IGF-1. The absence of exon 3 was also associated with abgreater likelihood of failing to achieve normal IGF-I after both surgical and medical treatment. In carriers of d3-GHR, lower doses of PEG (Pegvisomant) were required; the mechanism of this increased sensitivity is unknown.These patients may also have a higher prevalence of acromegalic comorbidities. These studies demonstrate the importance of the GHR genotype, which may not only contribute to predict clinical outcome, but also help to identify the optimal therapy for each patient.

Correlation of growth hormone receptor and its signal pathway defects with the phenotype: A study of 21 cases with growth hormone insensitivity syndrome / 中华内分泌代谢杂志

Objective To detect the relationship between the molecular defects and their phenotypes in children with growth hormone insensitivity syndrome (GHIS).Methods 21 patients defined as GHIS were enrolled in the study.4 candidate genes (GHR,IGFALS,JAK2,and STAT5B) were analyzed by genomic DNA sequence screening and clinical relevance analysis.Results The statistical descriptions of the patients were showed as an average height standard deviation (SDS)-4.33 ± 1.91 (-9.17 to-2.21),average serum peak values of GH (22.67 ±20.98) tg/L (11.33 to 104.21 μg/L),basal serum insulin-like growth factor-Ⅰ SDS-2.65 ± 0.53 (-3.57 to -1.79),insulin-like growth factor-binding protein 3 SDS-1.77 ± 1.64 (-4.13 to 0.96).Bone age of backward difference (chronological age-bone age) (43.10 ± 19.54) months (6 to 82 months).One of two children with severe growth failure and mid-face hypoplasia was found to a homozygote for G to A gene mutation in the intron 6 splice donor consensus sequences (IVS6 ds+ 1 G-A) in the GHR gene,causing its functional defect.3 cases with mild dwarf were found gene variations as novel finding:c.1097T＞C c.1098C＞T p.V366A pathogenic variant,c.1229C＞T p.S410L and nt1843707 A→G of 5' UTR region in the IGFALS gene.JAK2 and STAT5b genes mutations were not found.Conclusion Molecular pathology of GHIS is considered as involving the defects of GHR and its signal pathway.The mutation of intron 6 splice donor sequences in GHR gene has been reported which affect the function of GHR.The 3 novel type base variants in IGFALS gene,causing non severe dwarfism,might be suspected with pathogenic roles of GHIS.

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.

Multidimensional Comparison of Personality Characteristics in Genetic High Risk for Schizophrenia, First Episode Psychosis and Healthy Controls / 대한정신분열병학회지

OBJECTIVES: Previous studies have suggested that some personality characteristics are associated with the onset, prognosis and social function in schizophrenia patients. However few is known about the personality and affective characteristic of genetic high risk group (GHR) for schizophrenia. This study aimed to investigate the personality and the affective characteristic of GHR group for schizophrenia. METHODS: Participants were 54 healthy controls (HC), 26 subjects with GHR for schizophrenia and 28 subjects with first episode psychosis (FEP). We performed three self-report questionnaires; NEO-Personality Inventory-Revised, State and Anger Expression Inventory and Positive Affect and Negative Affect Schedule. RESULTS: The GHR group showed higher score in agreeableness item than the HC (p=0.028). In extraversion item, the FEP group showed significantly lower scores than the HC (p=0.001). The GHR group showed lower scores in neuroticism item compared with FEP group in trend level. The FEP group showed higher trait-anger, lower positive affect and higher negative affect compared with the others. CONCLUSION: The GHR group seem to share certain vulnerable personality and affective characteristics for schizophrenia with the FEP group. On the other hands, the GHR group appeared to be more agreeable than the other groups, which might act as the compensation for other impaired functions.

Evaluación de los niveles séricos de la proteína de unión de alta afinidad de la hormona de crecimiento humana (GHBP) y del polimorfismo del exón 3 del gen del receptor de GH en niños con talla baja idiopática / Evaluation of serum levels of the high affinity binding protein of human growth hormone (GHBP) and exon 3 polymorphism of the GH receptor gene in children with idiopathic short stature

La talla baja idiopática (TBI) incluye a un grupo heterogéneo de pacientes con fallas en su crecimiento. Una causa probable de TBI puede ser la insensibilidad a la GH (IGH). La proteína de unión de GH de alta afinidad (GHBP) se genera por el clivaje proteolítico de la porción extracelular del receptor de GH (GHR) y su determinación se propone como un marcador periférico del nivel de GHR en los tejidos. El objetivo de este trabajo fue evaluar los niveles de GHBP circulantes y su asociación con factores de crecimiento y el polimorfismo del exón 3 del gen GHR en niños con TBI. Los niños con TBI presentaron talla, IMC, IGF-I, IGFBP-3, ALS y niveles de GHBP significativamente más bajos que un grupo de niños de edad comparable (p<0.001). El genotipo del exón 3 del GHR no fue un factor determinante de las diferencias observadas. La máxima respuesta de GH de los tests de estímulo de secreción correlacionó negativa y significativamente con los niveles de GHBP (r= -0.28, p= 0.012). Los perfiles de distribución de la concentración de GHBP, IGF-I, ALS y BP3 expresadas en score de desvío estándar (SDE) en la TBI, mostraron un sesgo hacia niveles bajos. En conclusión, los marcadores de acción de GH y los niveles de GHBP fueron bajos en la TBI, independientemente del genotipo del exón 3 del gen GHR. En un subgrupo de niños con TBI, niveles disminuidos de GHBP y de componentes del sistema de los IGFs, colaborarían en la evaluación de la IGH sugiriendo la búsqueda de defectos en el GHR.

Idiopathic Short Stature (ISS) includes a heterogeneous group of children with growth failure. One possible explanation for the growth failure is a reduced responsiveness to growth hormone (GH). Human circulating GH is partially bound to a highaffinity binding protein (GHBP) which is derived from proteolytical cleavage of the extracellular domain of the GH receptor. Many reports have demonstrated a close relationship between GHBP and liver GH receptor status in physiological conditions and diseases. Moreover, serum GHBP measurement has been proposed as an useful peripheral index of GH receptor abundance. Our objective was the evaluation of serum GHBP levels and its probable association with serum growth factors (IGF-I, IGFBP-3 and ALS) and the exon 3 polymorphism of the extracellular domain of the GHR gene in ISS children. Children with ISS presented significantly lower height SDS, BMI SDS, serum components of the IGFs system and GHBP concentration as compared to an age-matched control group of normal children (p<0.001). Interestingly, exon 3 genotype did not influence the differences observed in these parameters. The maximal GH response obtained after two GH provocative tests inversely and significantly correlated to GHBP serum levels (r= -0.28, p= 0.012). A frequency study showed a deviation to low SDS values of serum GHBP, IGF-I, IGFBP-3 and ALS. Conclusion: 1- in children with ISS the exon 3 genotype of the GHR gene is not a factor that could explain the lower levels observed in circulating GHBP concentration and components of the IGFs system; 2- low serum GHBP together with low IGF-I, IGFBP-3 or ALS levels would help pointing to GH insensitivity due to GH receptor gene abnormalities in ISS.

Distribución de las frecuencias alélicas y genotípicas del polimorfismo GHRd3 en pacientes venezolanos con talla baja

Objetivos. La deleción (GHRd3) o inserción (GHRfl) del exón 3 es un polimorfismo común en el gen del receptor de la hormona de crecimiento (GHR) en los seres humanos. La presencia del alelo GHRd3 se ha asociado con el grado de respuesta de terapia con Hormona de Crecimiento Recombinante Humana (rhGH). El objetivo de este estudio fue determinar las frecuencias alélicas y genotípicas de este polimorfismo en un grupo de 69 niños venezolanos con talla baja que estaban recibiendo rhGH. Métodos. Se extrajo DNA a través de la técnica del método combinado Fenol/Sevag e Inorgánica. Se determinó el genotipo del exón 3 del gen GHR usando tanto PCR- monoplex como PCR-multiplex. Resultados. Entre los pacientes con talla baja la frecuencia genotípica se distribuyó de la siguiente manera: GHRfl/GHRfl (55%) GHRfl/GHRd3 (35%) y GHRd3/GHRd3 (10%) y la frecuencia alélica fue de 0,27 para GHRd3 y 0,73 para GHRfl. Para el grupo testigo la frecuencia genotípica se distribuyo así: GHRfl/GHRfl (56%), GHRfl/ GHRd3 (30%) y GHRd3/GHRd3 (14%) y la frecuencia alélica era de 0,29 para GHRd3 y 0,71 para GHRfl. Las características clínicas basales de los pacientes con talla baja eran similares entre los diferentes genotipos encontrados en el grupo de estudio. Conclusiones. La proporción del genotipo y los alelos del gen GHR fueron similares entre el grupo testigo y los pacientes con talla baja, lo que traduce que la etiología de la talla baja no obedece a este polimorfismo.

Objective. The deletion (GHRd3) or insertion (GHRfl) of exon 3 is a common polymorphism in the receptor growth hormone gene (GHR) in humans. The presence of the allele GHRd3 has been associated with the degree of responsiveness to therapy with recombinant human Growth Hormone (rhGH). The aim of this study was to determine the genotypic and allele frequencies of this polymorphism in a group of 69 Venezuelan children with short stature who were receiving rhGH. Methods. Genomic DNA was extracted from blood lymphocytes using combined method Fenol/SEVAG + Salting out. The GHR-exon 3 was genotyped using both PCR monoplex and multiplex assays. Results. Among patients with short stature, genotype frequency was distributed as follows: GHRfl/GHRfl (55%), GHRfl/GHRd3 (35%) and GHRd3/GHRd3 (10%) and allele frequency for GHRd3 and GHRfl was 0.27 and 0.73, respectively. For the control group, genotype frequency was distributed as follows: GHRfl/GHRfl (56%), GHRfl/GHRd3 (30%) and GHRd3/GHRd3 (14%) and allele frequency for GHRd3 and GHRfl was 0.29 and 0.71, respectively. The baseline clinical features of patients with short stature were similar among different genotypes found in the study group. Conclusions. The proportion of genotype and allele of the GHR gene were similar between the control group and patients with short stature, which translates that the etiology of short stature is not due to this polymorphism.

El receptor de la hormona de crecimiento humana (hGH) y la proteína de transporte de alta afinidad de la hGH / Human Growth Hormone (GH) Receptor and the High Affinity GH-Binding Protein

La hormona de crecimiento humana (hGH) circula parcialmente unida a su proteína de transporte de alta afinidad (GHBP) la cual resulta del clivaje proteolítico del dominio extracelular del receptor de GH. Recientemente la enzima TACE se identificó como la metaloproteasa responsable del clivaje y liberación de GHBP a circulación. Aunque aún se desconoce la función específica de esta proteína de transporte, distintos trabajos en la literatura demuestran efectos que potencian y efectos inhibitorios sobre la acción de GH. Por otro lado, existen evidencias que demuestran una fuerte relación entre la GHBP y el nivel de receptor de GH en el hígado en situaciones fisiológicas y patológicas. Esto permitió proponer a la determinación de GHBP en suero como un marcador periférico de la abundancia del receptor de GH en los tejidos. La determinación de la concentración de GHBP sería de especial interés para evaluar pacientes con diagnóstico probable de insensibilidad a la acción de GH y orientar el posterior estudio de anormalidades en el gen del receptor de GH. En la presente revisión, también se abordan dificultades metodológicas relacionadas a la medición de GHBP sérica.

Human circulating growth hormone (GH) is partly bound to a high-affinity binding protein (GHBP) which is derived from proteolytical cleavage of the extracellular domain of the GH receptor. Recently, the metalloproteinase TACE has been identified as an important enzyme responsive for inducing GHBP shedding. Although the specific function of GHBP is not fully known, both enhancing and inhibitory roles of this binding protein on GH action have been proposed. Many reports have demonstrated a close relationship between GHBP and the liver GH receptor status in physiological conditions and diseases. Moreover, serum GHBP measurement has been proposed as an useful peripheral index of the GH receptor abundance. Related to the latter, circulating GHBP concentration would be of special interest for the evaluation of GH insensitivity due to GH receptor gene abnormalities. In addition, the present review also focus on methodological problems concerning serum GHBP measurement.

Expression of Growth Hormone Receptor Gene During 3T3-L1 Differentiation / 대한소아내분비학회지

PURPOSE: Growth hormone(GH) produces a variety of effects in adipose tissue via GHRs on the cell membrane. In mouse, alternative splicing of the nascent transcript from the GHR gene produces two major transcripts:GHR mRNA and GHR binding protein(GHBP) mRNA. These two transcripts share the common extracellular ligand-binding domain, but differ in the C-terminal sequence. Since GHR plays an important role in mediating the actions of GH in adipose metabolism, I initiated these studies to examine GHR gene expression during mouse 3T3-Ll preadipocyte-adipocyte differentiation. METHODS: GHR and GHBP transcripts were detected by RNase protection assay (RPA) using the antisense riboprobes complementary either to the specific sequence of the GHR or to the sequence shared by both GHR and GHBP mRNAs. RNA prepared from 3T3-L1 cells at day 0(preadipocytes) and day 7(adipocytes) after treatment with actinomycin D was analyzed by RPA. RESULTS: After stimulation of differentiation, mRNA abundance increased 25-fold and reached a maximal level by day 7 of adipogenesis. The GHR mRNA:GHBP mRNA ratio was 1.3+/-.15 and remained unchanged during differentiation. The decay rate for both mRNAs, estimated by treating the cells with actinomycin D, was approximately 24 hours and showed no significant difference between preadipocytes and adipocytes. CONCLUSION: GHR gene expression is upregulated during preadipocyte-adipocyte differentiation.