Growth hormone - past, present and future

Growth hormone promotes the reconstruction of injured axons in the hypothalamo-neurohypophyseal system

JOURNAL/nrgr/04.03/01300535-202410000-00026/figure1/v/2024-02-06T055622Z/r/image-tiff Previous studies have shown that growth hormone can regulate hypothalamic energy metabolism, stress, and hormone release. Therefore, growth hormone has great potential for treating hypothalamic injury. In this study, we established a specific hypothalamic axon injury model by inducing hypothalamic pituitary stalk electric lesions in male mice. We then treated mice by intraperitoneal administration of growth hormone. Our results showed that growth hormone increased the expression of insulin-like growth factor 1 and its receptors, and promoted the survival of hypothalamic neurons, axonal regeneration, and vascular reconstruction from the median eminence through the posterior pituitary. Altogether, this alleviated hypothalamic injury-caused central diabetes insipidus and anxiety. These results suggest that growth hormone can promote axonal reconstruction after hypothalamic injury by regulating the growth hormone-insulin-like growth factor 1 axis.

Genetic variants of LEAP2 are associated with anthropometric traits and circulating insulin-like growth factor-1 concentration: A UK Biobank study

AIM

To test the hypothesis that liver-expressed antimicrobial peptide 2 (LEAP2) genetic variants might influence the susceptibility to human obesity.

METHODS

Using data from the UK Biobank, we identified independent LEAP2 gene single nucleotide polymorphisms (SNPs) and examined their associations with obesity traits and serum insulin-like growth factor-1 (IGF-1) concentration. These associations were evaluated for both individual SNPs and after combining them into a genetic risk score (GRSLEAP2) using linear and logistic regression models. Sex-stratified analyses were also conducted.

RESULTS

Five SNPs showed positive associations with obesity-related traits. rs57880964 was associated with body mass index (BMI) and waist-to-hip ratio adjusted for BMI (WHRadjBMI), in the total population and among women. Four independent SNPs were positively associated with higher serum IGF-1 concentrations in both men and women. GRSLEAP2 was associated with BMI and WHRadjBMI only in women and with serum IGF-1 concentration in both sexes.

CONCLUSIONS

These findings reveal sex-specific associations between key LEAP2 gene variants and several obesity traits, while also indicating a strong independent association of LEAP2 variants with serum IGF-1 concentration.

Insights into the ANKRD11 variants and short-stature phenotype through literature review and ClinVar database search

Ankyrin repeat domain containing-protein 11 (ANKRD11), a transcriptional factor predominantly localized in the cell nucleus, plays a crucial role in the expression regulation of key genes by recruiting chromatin remodelers and interacting with specific transcriptional repressors or activators during numerous biological processes. Its pathogenic variants are strongly linked to the pathogenesis and progression of multisystem disorder known as KBG syndrome. With the widespread application of high-throughput DNA sequencing technologies in clinical medicine, numerous pathogenic variants in the ANKRD11 gene have been reported. Patients with KBG syndrome usually exhibit a broad phenotypic spectrum with a variable degree of severity, even if having identical variants. In addition to distinctive dental, craniofacial and neurodevelopmental abnormalities, patients often present with skeletal anomalies, particularly postnatal short stature. The relationship between ANKRD11 variants and short stature is not well-understood, with limited knowledge regarding its occurrence rate or underlying biological mechanism involved. This review aims to provide an updated analysis of the molecular spectrum associated with ANKRD11 variants, investigate the prevalence of the short stature among patients harboring these variants, evaluate the efficacy of recombinant human growth hormone in treating children with short stature and ANKRD11 variants, and explore the biological mechanisms underlying short stature from both scientific and clinical perspectives. Our investigation indicated that frameshift and nonsense were the most frequent types in 583 pathogenic or likely pathogenic variants identified in the ANKRD11 gene. Among the 245 KBGS patients with height data, approximately 50% displayed short stature. Most patients showed a positive response to rhGH therapy, although the number of patients receiving treatment was limited. ANKRD11 deficiency potentially disrupts longitudinal bone growth by affecting the orderly differentiation of growth plate chondrocytes. Our review offers crucial insights into the association between ANKRD11 variants and short stature and provides valuable guidance for precise clinical diagnosis and treatment of patients with KBG syndrome.

Can the reduced GH, IGF-1, and ovarian steroids concentrations be considered as suspected biomarkers of age-associated functional deficit in mares?

In humans' and experimental animals' components of the somatotropic axis, such as growth hormone (GH) and insulin-like growth factor 1 (IGF-1) concentrations, decrease with advancing age. Although there is evidence regarding IGF-1, the effect of age on GH in mares, as well as the relationships between both parameters, have not yet been elucidated. On the other hand, although GH and IGF-1 are related to follicular development, it is unknown if they could be correlated with the circulating concentrations of ovarian steroids in mares, as occurs in other species. The hypothesis of this study was that both GH and IGF-1 could experience physiological changes with advancing age also in mares, and that both GH/IGF-1 could be correlated with oestradiol-17β (E2) and progesterone (P4), as recorded for other species. Hence, the objective of this study was to evaluate the concentrations of GH, IGF-1, E2, and P4 in mares, according to the different ages. Blood samples were drawn from 56 healthy cyclic Spanish Purebred mares belonging to four different age groups: 6-9 years, 10-13 years, 14-16 years and >16 years. Mares aged 6-9 years and 10-13 years showed higher GH concentrations (P < 0.05) than mares of 14-16 and >16 years; and mares aged 14-16 showed higher GH concentrations (P < 0.05) than >16 years (P < 0.05). Mares aged >16 years showed lower IGF-1 concentrations (P < 0.05) than mares of 6-9, 10-13 and 14-16 years (P < 0.05). The concentrations of E2 and P4 showed no significant differences among different age groups. Both GH and IGF-1 were not correlated with each other or with E2 and P4. The concentrations of E2 and P4 did not change with age. Advancing age leads to a decrease in the activity of the somatotropic axis in physiological cyclic mares, represented by a significant GH reduction, which, however, was ascribed for IGF-1 exclusively to mares over 16 years of age, without alterations in steroid hormone patterns.

Association of circulating leptin, growth hormone, and ghrelin with fibromyalgia: A meta-analysis

OBJECTIVE

The aim of this study was to evaluate the relationship between levels of leptin, growth hormone (GH), and ghrelin in the bloodstream and fibromyalgia.

METHODS

We conducted a meta-analysis to compare the serum/plasma levels of leptin, GH, and ghrelin in individuals with fibromyalgia, as compared to healthy controls. The analysis included sixteen articles, which provided data from 697 fibromyalgia patients and 560 controls.

RESULTS

The meta-analysis found that there was no significant difference in leptin levels between fibromyalgia patients and controls overall (SMD = 0.324, 95% CI = -0.264 to 0.913, P = 0.281). However, when subgroup analysis was done based on geographically different populations, it showed a positive association between high leptin levels and fibromyalgia in European populations (SMD = 1.131, 95% CI = 0.197 to 2.064, P = 0.018), while no significant association was found in Latin American populations (SMD = -0.160, 95% CI = -0.847 to 0.528, P = 0.649). As for GH levels, there was no significant difference between fibromyalgia patients and controls overall (SMD = -0.903, 95% CI = -2.036 to 0.231, P = 0.119). However, when subgroup analysis was done based on geographically different populations, it revealed a significant decrease in GH levels in European populations with fibromyalgia (SMD = -2.341, 95% CI = -3.664 to -1.017, P = 0.001), while no significant association was found in North American populations. Lastly, the analysis of ghrelin levels showed no significant association with fibromyalgia overall (SMD = -0.661, 95% CI = -1.382 to 0.059, P = 0.072).

CONCLUSION

This meta-analysis shows that patients with fibromyalgia in Europeans have significantly higher levels of circulating leptin and GH. However, no significant association was found between ghrelin levels and fibromyalgia.

Update on the use of long-acting growth hormone in children

PURPOSE OF REVIEW

After extensive research and many years of waiting, long-acting growth hormone (LAGH) formulations have finally become a reality in clinical practice and emerge as a potential solution to address the challenges of daily injections of recombinant human GH (rhGH). In this review, we present a brief history of the development of LAGH and provide a critical analysis of the existing literature on the five LAGH available and approved to date for treatment in children.

RECENT FINDINGS

In clinical trials, LAGH therapy has shown noninferiority compared with daily rhGH therapy in promoting linear growth in children with GH deficiency, with similar rates of adverse events.

SUMMARY

In the real world, many questions still need to be answered, such as whether a specific group of patients will benefit most from the weekly injection, whether compliance will be better compared with daily rhGH, whether long-term efficacy, monitoring and safety profile will be the same for the different LAGH compounds, and whether the cost-effectiveness will justify their use in different settings.

Transdermal Delivery of Recombinant Human Growth Hormone by Liposomal Gel for Skin Photoaging Therapy

Human growth hormone (hGH) has emerged as a promising therapeutic agent to prevent and treat skin photoaging. However, the success of hGH therapy largely lies in the availability of an optimal delivery system that enables the efficient delivery of hGH to the dermal layer of the skin. Here, we report a delivery system of hyaluronic acid/liposome-gel-encapsulated hGH (HA/HL-Gel) that can transdermally deliver hGH into the skin for hGH-based photoaging therapy through the upregulation of collagen type I (collagen-I). Specifically, hGH-liposomes were prepared by ethanol injection and then modified with HA to achieve specific targeting. The best formulation of HA/hGH-liposomes (HA/HL) had a high encapsulation efficiency (about 20%), with a size of 180 ± 1.2 nm. The optimized HA/HL was further incorporated into the carbomer gel to form an HA/HL-Gel. The biological activity of HA/HL on human dermal fibroblasts (HDFs) was confirmed by the elevated expression level of collagen-I through the enhanced local formation of insulin-like growth factor-1 (IGF-1) in the photoaging model. Moreover, HA/HL-Gel reduced ultraviolet (UV)-induced erythema and wrinkle formation. Meanwhile, immunohistochemical staining further showed higher levels of collagen-I in the HA/HL-Gel group compared to other groups tested. Taken together, these results demonstrate that HA/HL-Gel treatment could significantly ameliorate skin photoaging and thus may be used as a clinical potential for antiaging therapy.

Detection of the GH analog somatrogon in sports drug testing: Immunological approaches and LC-HRMS/MS

Due to the presumed lipolytic and anabolic properties, the misuse of human growth hormone (hGH) and its synthetic analogs in sports is prohibited both in- and out-of-competition. Within this research project, the detectability of somatrogon, a recombinant fusion glycoprotein of 22 kDa hGH and the C-terminal peptide (CTP) of the human chorionic gonadotropin (hCG) β-subunit, with current WADA-approved doping control assays for hGH and hCG was investigated. For that purpose, cross-reactivity tests and a somatrogon administration study were conducted, and only "Kit 2" of the GH isoform differential immunoassays proved applicable to the detection of somatrogon administration in serum. In urine, the immunoassay specific for total hCG yielded presumptively positive findings for several post-administration samples, which can probably be attributed to the presence of an immunoreactive fragment of the hCG β-subunit. As the detectability of somatrogon with these approaches was found to be limited, a highly specific detection assay (LOD: 10 ng/mL) for the drug in serum samples was developed by using affinity purification with GH receptor (GHR)-conjugated magnetic beads, proteolytic digestion, and liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS). Following optimization, the approach was comprehensively characterized, and authentic post-administration serum samples were successfully analyzed as proof-of-concept, indicating a detection window of at least 96 h. Consequently, the presented method can be employed to confirm the presence of somatrogon in serum samples, where only "Kit 2" of the currently used immunoassay kits yielded an abnormally high Rec/Pit ratio.

Growth hormone promotes myelin repair after chronic hypoxia via triggering pericyte-dependent angiogenesis

White matter injury (WMI) causes oligodendrocyte precursor cell (OPC) differentiation arrest and functional deficits, with no effective therapies to date. Here, we report increased expression of growth hormone (GH) in the hypoxic neonatal mouse brain, a model of WMI. GH treatment during or post hypoxic exposure rescues hypoxia-induced hypomyelination and promotes functional recovery in adolescent mice. Single-cell sequencing reveals that Ghr mRNA expression is highly enriched in vascular cells. Cell-lineage labeling and tracing identify the GHR-expressing vascular cells as a subpopulation of pericytes. These cells display tip-cell-like morphology with kinetic polarized filopodia revealed by two-photon live imaging and seemingly direct blood vessel branching and bridging. Gain-of-function and loss-of-function experiments indicate that GHR signaling in pericytes is sufficient to modulate angiogenesis in neonatal brains, which enhances OPC differentiation and myelination indirectly. These findings demonstrate that targeting GHR and/or downstream effectors may represent a promising therapeutic strategy for WMI.

Fasting and prolonged food restriction differentially affect GH secretion independently of GH receptor signaling in AgRP neurons

Growth hormone (GH) receptor (GHR) is abundantly expressed in neurons that co-release the agouti-related protein (AgRP) and neuropeptide Y (NPY) in the arcuate nucleus of the hypothalamus (ARH). Since ARHAgRP/NPY neurons regulate several hypothalamic-pituitary-endocrine axes, this neuronal population possibly modulates GH secretion via a negative feedback loop, particularly during food restriction, when ARHAgRP/NPY neurons are highly active. The present study aims to determine the importance of GHR signaling in ARHAgRP/NPY neurons on the pattern of GH secretion in fed and food-deprived male mice. Additionally, we compared the effect of two distinct situations of food deprivation: 16 h of fasting or four days of food restriction (40% of usual food intake). Overnight fasting strongly suppressed both basal and pulsatile GH secretion. Animals lacking GHR in ARHAgRP/NPY neurons (AgRP∆GHR mice) did not exhibit differences in GH secretion either in the fed or fasted state, compared to control mice. In contrast, four days of food restriction increased GH pulse frequency, basal GH secretion, and pulse irregularity/complexity (measured by sample entropy), whereas pulsatile GH secretion was not affected in both control and AgRP∆GHR mice. Hypothalamic Ghrh mRNA levels were unaffected by fasting or food restriction, but Sst expression increased in acutely fasted mice, but decreased after prolonged food restriction in both control and AgRP∆GHR mice. Our findings indicate that short-term fasting and prolonged food restriction differentially affect the pattern of GH secretion, independently of GHR signaling in ARHAgRP/NPY neurons.

Magnetic resonance imaging of knees: a novel approach to predict recombinant human growth hormone therapy response in short-stature children in late puberty

BACKGROUND

There is no appropriate tool to predict recombinant human growth hormone (rhGH) response before therapy initiation in short-stature children in late puberty. The current study aimed to explore the associations between magnetic resonance imaging (MRI) stages of the knee growth plates and rhGH response in short-stature children in late puberty.

METHODS

In this prospective cohort study, short-stature children in late puberty were treated with rhGH and followed up for 6 months. We proposed a novel knee MRI staging system according to the growth plate states of distal femurs or proximal tibias and divided the participants into three groups: unclosed growth plate group, marginally closed growth plate group, and nearly closed growth plate group. The primary outcomes were height gain and growth velocity (GV), which were assessed three months later.

RESULTS

Fifty participants were enrolled, including 23 boys and 27 girls. GV and height gain after 6 months of rhGH therapy decreased successively in the three groups with an increased degree of growth plate fusion, especially when grouped by proximal tibias (GV1-3 mon from 9.38 to 6.08 to 4.56 cm/year, GV4-6 mon from 6.75 to 4.92 to 3.25 cm/year, and height gain from 4.03 to 2.75 to 1.95 cm, all P < 0.001). Moreover, the MRI stages of growth plates independently served as a significant variable for GV and height gain after therapy, especially when grouped by proximal tibias (all P < 0.01).

CONCLUSION

The MRI staging method is expected to be an effective tool for predicting rhGH response before therapy initiation in short-stature children in late puberty.

Treatment of acromegaly with oral octreotide

Acromegaly is a rare disease caused by a growth hormone excess, usually due to a secreting pituitary adenoma. Somatostatin receptor ligands (SRL) are the mainstay of medical therapy for patients with acromegaly who fail to achieve biochemical control post-operatively or are not eligible for surgical treatment. SRLs are typically administered as monthly injections and have shown to be effective in maintaining biochemical and radiological control of acromegaly. However, these injections may cause local adverse events and are associated with increased psychological burden in some patients. Oral octreotide provides a new alternative for patients responding to injectable SRLs. This new formulation has shown to have similar safety and efficacy profiles compared to injectable SRLs and may be a preferable option for some patients with acromegaly. The aim of this review is to provide an overview of the role of oral octreotide in the management of acromegaly.

Differential peptide-dependent regulation of growth hormone (GH): A comparative analysis in pituitary cultures of reptiles, birds, and mammals

Growth hormone (GH) is a pituitary protein that exerts pleiotropic roles in vertebrates. The mechanisms regulating GH synthesis and secretion are finely controlled by hypothalamic neuropeptides and other factors. These processes have been considerably studied in mammals but are still poorly understood in other groups. To better understand the pituitary GH regulation during vertebrate phylogeny, we compared the effects of incubating several peptides on cultures of ex-vivo pituitary fragments obtained from representative specimens of reptiles (iguana), birds (chicken) and mammals (rat). The peptides used were: growth hormone-releasing hormone (GHRH), thyrotropin-releasing hormone (TRH), pituitary adenylate cyclase-activating polypeptide (PACAP), ghrelin, gonadotropin-releasing hormone (GnRH), and somatostatin (SST). In rat pituitary cultures, GH secretion was stimulated by GHRH and TRH, while gh mRNA expression was increased by GHRH and PACAP. In the case of chicken pituitaries, GH release was promoted by GHRH, ghrelin, PACAP, and GnRH, although the latter two had a dual effect since at a shorter incubation time they decreased GH secretion; in turn, gh mRNA expression was significantly stimulated by TRH, PACAP, and GnRH. The most intense effects were observed in iguana pituitary cultures, where GH secretion was significantly augmented by GHRH, PACAP, TRH, ghrelin, and GnRH; while gh mRNA expression was stimulated by GHRH, TRH, and PACAP, but inhibited by ghrelin and SST. Also, in the three species, SST was able to block the GHRH-stimulated GH release. Furthermore, it was found that the expression of Pou1f1 mRNA was increased with greater potency by GHRH and PACAP in the iguana, than in chicken or rat pituitary cultures. Additionally, in-silico analysis of the gh gene promoter structures in the three species showed that the reptilian promoter has more Pit-1 consensus binding sites than their avian and mammalian counterparts. Taken together, results demonstrate that pituitary peptide-mediated GH regulatory mechanisms are differentially controlled along vertebrate evolution.

Relationship between Serum Sirtuin 1 and Growth Hormone/Insulin-like Growth Factor 1 Concentrations in Children with Growth Hormone Deficiency and Idiopathic Short Stature

Sirtuin 1 (SIRT1) inhibits growth hormone (GH) intracellular signaling for the insulin-like growth factor 1 (IGF-1) synthesis via the janus kinase (JAK)/signal transducer and activator of transcription proteins (STATs) pathway. The aim of this study was to compare SIRT1 concentrations in children with GH deficiency (GHD) and so-called idiopathic short stature (ISS, non-GH deficient), in order to determine the possible impact of changes in serum SIRT1 concentrations on the GH-IGF-1 axis. The study group included 100 short-stature children: 38 with GHD and 62 with ISS (maxGH in two stimulation tests <10 and ≥10 ng/mL, respectively). The control group consisted of 47 healthy, normal-height children. For each child, the concentrations of SIRT1, IGF-1 and insulin-like growth factor-binding protein 3 (IGFBP-3) were determined and the IGF-1/IGFBP-3 molar ratio was calculated. The level of SIRT1 was significantly higher in both groups of short children than in the controls (p < 0.0001), but there were no differences between GHD and ISS (mean ± SD: 0.89 ± 0.45 for ISS; 1.24 ± 0, 86 for GHD; and 0.29 ± 0.21 for controls). A significant negative correlation was found between SIRT1 and height standard deviation score (SDS), IGF-1 and IGF-1/IGFBP-3, but not between SIRT1 and maxGH. Elevated SIRT1 levels may serve as one of the mechanisms through which the secretion of IGF-1 is reduced in children with short stature; however, further research is required to confirm this issue.

Targeting Nrf2 by bioactive peptides alleviate inflammation: expanding the role of gut microbiota and metabolites

Inflammation is a complex process that usually refers to the general response of the body to the harmful stimuli of various pathogens, tissue damage, or exogenous pollutants. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that regulates cellular defense against oxidative damage and toxicity by expressing genes related to oxidative stress response and drug detoxification. In addition to its antioxidant properties, Nrf2 is involved in many other important physiological processes, including inflammation and metabolism. Nrf2 can bind the promoters of antioxidant genes and upregulates their expressions, which alleviate oxidation-induced inflammation. Nrf2 has been shown to upregulate heme oxygenase-1 expression, which promotes NF-κB activation and is closely related with inflammation. Nrf2, as a key factor in antioxidant response, is closely related to the expressions of pro-inflammatory factors, NF-κB pathway and cell metabolism. Bioactive peptides come from a wide range of sources and have many biological functions. Increasing evidence indicates that bioactive peptides have potential anti-inflammatory activities. This article summarized the sources, absorption and utilization of bioactive peptides and their role in alleviating inflammation via Nrf2 pathway. Bioactive peptides can also regulate gut microbiota and alter metabolites, which regulates the Nrf2 pathway through novel pathway and supplement the anti-inflammatory mechanisms of bioactive peptides. This review provides a reference for further study on the anti-inflammatory effect of bioactive peptides and the development and utilization of functional foods.

Longitudinal unraveling: The impact of recombinant human growth hormone on spontaneous brain activity in children with short stature-A resting-state fMRI study

Recombinant human growth hormone (rhGH) is an approved method to improve the growth and ameliorate behavioral issues in children with short stature. However, the data concerning the effects of rhGH treatment on spontaneous brain activity remains unclear. This study included 35 children with short stature, categorized into two groups: the treated group (n = 14) and the untreated group (n = 21). All participants underwent resting-state functional magnetic resonance imaging (rs-fMRI) and neuropsychological assessments at baseline and at the end of a one-year follow-up. The rs-fMRI based amplitude of low frequency fluctuation (ALFF) analysis method was employed to assess spontaneous brain activity. Interaction effects between rhGH and time on ALFF were detected using a mixed-effects analysis. Additionally, Stepwise regression analysis was conducted to investigate the associations between ALFF values and significant clinical indicators. The treated group exhibited significant improvements in height, weight, insulin-like growth factor-1 (IGF-1) levels, insulin-like growth factor binding protein 3 (IGFBP-3) levels, and processing speed index (PSI) when reevaluated from baseline. The interaction effect of rhGH × time was evident in the right putamen (RPUT), where the ALFF value showed a significant increase following rhGH treatment, while also demonstrating a notable positive correlation with height. Moreover, The main effect of time was manifested as a significant decrease in the ALFF value of the left dorsolateral superior frontal gyrus (LSFG) within the untreated group during the follow-up period, concurrently displaying a positive correlation with age. In conclusion, rhGH treatment not only has a positive effect on the growth, cognition, and behavior of children with short stature, but also improves and normalizes spontaneous brain activity.

Experimental Autoimmune Encephalomyelitis Influences GH-Axis in Female Rats

Inflammation, demyelination, and axonal damage to the central nervous system (CNS) are the hallmarks of multiple sclerosis (MS) and its representative animal model, experimental autoimmune encephalomyelitis (EAE). There is scientific evidence for the involvement of growth hormone (GH) in autoimmune regulation. Previous data on the relationship between the GH/insulin like growth factor-1 (IGF-1) axis and MS/EAE are inconclusive; therefore, the aim of our study was to investigate the changes in the GH axis during acute monophasic EAE. The results show that the gene expression of Ghrh and Sst in the hypothalamus does not change, except for Npy and Agrp, while at the pituitary level the Gh, Ghrhr and Ghr genes are upregulated. Interestingly, the cell volume of somatotropic cells in the pituitary gland remains unchanged at the peak of the disease. We found elevated serum GH levels in association with low IGF-1 concentration and downregulated Ghr and Igf1r expression in the liver, indicating a condition resembling GH resistance. This is likely due to inadequate nutrient intake at the peak of the disease when inflammation in the CNS is greatest. Considering that GH secretion is finely regulated by numerous central and peripheral signals, the involvement of the GH/IGF-1 axis in MS/EAE should be thoroughly investigated for possible future therapeutic strategies, especially with a view to improving EAE disease.

Evaluation of the safety and efficacy of biosimilar recombinant growth hormone in children with growth hormone deficiency: non-inferiority, randomized, parallel, multicentric and Phase III trial

OBJECTIVES

This study is designed in order to compare the efficacy and safety of recombinant human growth hormone (rhGH) with the reference brand.

METHODS

According to the inclusion criteria, 85 people in 13 Iranian centers were randomly selected to receive biosimilar Somatropin (Somatin®) (44 people) and reference Somatropin (Norditropin®) (41 people) at a dose of 35 µg/kg/d, seven days/week for 12 months. The primary outcomes included height velocity (HV) was measured during 12 months of treatment.

RESULTS

The two intervention groups' Height changes were similar. The mean HV was 10.96 cm/year in the biosimilar group and 10.05 cm/year in the reference groups after 12 months. Estimates of the lower bounds of 95% CI for mean height differences in the biosimilar intervention group compared to the reference intervention group did not exceed the 2 cm margin. Therefore, the non-inferiority of biosimilar intervention compared to the brand product is verified. Common ADRs in both groups were nausea in two patients (2.4%), diarrhea in two patients (2.4%), increased body temperature in one patient (1.2%), and headache in one patient (1.2%).

CONCLUSIONS

The finding of this study indicated that Somatin® and Norditropin® have comparable efficacy and safety profiles.

CLINICAL TRIAL REGISTRATION

www.IRCT.irIRCT20171122037571N1.

Combined transcriptomics and metabolomics to analyse the response of Cuminum cyminum L. under Pb stress

Lead (Pb) can disrupt plant gene expression, modify metabolite contents, and influence the growth of plants. Cuminum cyminum L. is highly adaptable to adversity, but molecular mechanism by which it responds to Pb stress is unknown. For this study, transcriptomic and metabolomic sequencing was performed on root tissues of C. cyminum under Pb stress. Our results showed that high Pb stress increased the activity of peroxidase (POD), the contents of malondialdehyde (MDA) and proline by 80.03 %, 174.46 % and 71.24 %, respectively. Meanwhile, Pb stress decreased the activities of superoxide dismutase (SOD) and catalase (CAT) as well as contents of soluble sugars and GSH, which thus affected the growth of C. cyminum. In addition, Pb stress influenced the accumulation and transport of Pb in C. cyminum. Metabolomic results showed that Pb stress affected eight metabolic pathways involving 108 differentially expressed metabolites, primarily amino acids, organic acids, and carbohydrates. The differentially expressed genes identified through transcriptome analysis were mainly involved the oxidation reductase activity, transmembrane transport, phytohormone signaling, and MAPK signaling pathway. The results of this study will help to understand the molecular mechanisms of C. cyminum response to Pb stress, and provide a basis for screening seeds with strong resistance to heavy metals.

Hormones and B-cell development in health and autoimmunity

The development of B cells into antibody-secreting plasma cells is central to the adaptive immune system as they induce protective and specific antibody responses against invading pathogens. Various studies have shown that, during this process, hormones can play important roles in the lymphopoiesis, activation, proliferation, and differentiation of B cells, and depending on the signal given by the receptor of each hormone, they can have a positive or negative effect. In autoimmune diseases, hormonal deregulation has been reported to be related to the survival, activation and/or differentiation of autoreactive clones of B cells, thus promoting the development of autoimmunity. Clinical manifestations of autoimmune diseases have been associated with estrogens, prolactin (PRL), and growth hormone (GH) levels. However, androgens, such as testosterone and progesterone (P4), could have a protective effect. The objective of this review is to highlight the links between different hormones and the immune response mediated by B cells in the etiopathogenesis of systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and multiple sclerosis (MS). The data collected provide insights into the role of hormones in the cellular, molecular and/or epigenetic mechanisms that modulate the B-cell response in health and disease.

Trends of correlations between serum levels of growth hormone and insulin-like growth factor-I in general practice

Serum levels of growth hormone (GH) and insulin-like growth factor (IGF)-I are crucial in the diagnosis and management of GH-related diseases. However, these levels are affected by nutritional and metabolic status. To elucidate the correlations between GH and IGF-I in various conditions, a retrospective analysis was performed for adult patients in which GH levels were examined by general practitioners during the period from January 2019 to December 2021. Of 642 patients, 33 patients were diagnosed with acromegaly, 21 were diagnosed with GH deficiency (GHD), and 588 were diagnosed with non-GH-related diseases (NGRD). In contrast to the positive correlations found between the levels of GH and IGF-I in patients with acromegaly (R=0.50; P<0.001) and patients with GHD (R=0.39; P=0.08), a negative correlation was found in the NGRD group (R=-0.23; P<0.001). In that group, the results of multivariable analysis showed that GH levels were predominantly influenced by gender and body mass index (BMI), whereas IGF-I levels were modulated by albumin in addition to age and GH. Of note, in the NGRD group, there was an enhanced negative correlation between GH and IGF-I under conditions of BMI < 22 and albumin < 4.0 g/dL (R=-0.45; P<0.001), and the negative correlation between GH and IGF-I was reinforced by excluding patients with other pituitary diseases and patients taking oral steroids (R=-0.51; P<0.001 and R=-0.59; P<0.001, respectively). Collectively, the results indicate that attention should be given to the presence of a negative correlation between serum levels of GH and IGF-I, especially in lean and low-nutritious conditions.

Long-term risk of neoplastic events after childhood growth hormone treatment: a population-based cohort study in Sweden

Background

Increased risk of neoplastic events after recombinant human growth hormone (rhGH) treatment in childhood has been an ongoing concern but long-term safety data are limited.

Methods

A nationwide population-based cohort study in Sweden of patients treated with rhGH during childhood between 1985-2010, due to isolated growth hormone deficiency (GHD), small for gestational age (SGA) and idiopathic short stature (ISS). The comparison group consisted of 15 age-, sex-, and region-matched controls per patient, randomly selected from the general population. Data on neoplastic events and covariates, such as gestational age, birth weight, birth length, socioeconomic status, and height at study start, were collected through linkage with population-based registers. The cohort was followed for neoplastic events until the end of 2020.

Results

53,444 individuals (3,408 patients; 50,036 controls) were followed for up to 35 years, with a median follow-up of 19.8 years and a total of 1,050,977 person-years. Patients showed a moderately increased hazard ratio (HR) for neoplastic events overall compared to controls (HR 1.28, 95% CI: 1.12-1.46), but only significant for males (HR 1.39, 95% CI: 1.17-1.66) and not females (HR 1.15, 95% CI: 0.94-1.41). Longer treatment duration was associated with an increased HR, but no association was found between neoplastic events and mean or cumulative dose. No increased risk of malignant neoplasms was observed for the patients compared to matched controls (HR 0.91 95% CI: 0.66-1.26).

Conclusion

No association was found between rhGH treatment during childhood for GHD, SGA, or ISS and malignant neoplastic events in early to mid-adulthood. A moderate increase in overall neoplastic events was observed due to an increased number of events in male patients.

Safety and Effectiveness of a Biosimilar Recombinant Human Growth Hormone in Children Requiring Growth Hormone Treatment: Analysis of Final Data from PATRO Children, an International, Post-Marketing Surveillance Study

Purpose

Omnitrope® (somatropin) was approved as a biosimilar recombinant human growth hormone (rhGH) in 2006. Here, we report final data from the PAtients TReated with Omnitrope® (PATRO) Children study, a post-marketing surveillance study designed to monitor the long-term safety and effectiveness of this treatment in pediatric patients.

Methods

The study population included all pediatric patients treated with Omnitrope® (biosimilar rhGH), administered via daily injection, in routine clinical practice. The primary objective was to assess long-term safety, with effectiveness assessed as a secondary objective.

Results

In total, 7359 patients were enrolled and treated in the PATRO Children study; 86.0% were treatment-naïve at baseline. Growth hormone deficiency was the most frequent indication (57.9%), followed by patients born small for gestational age (SGA; 26.6%). The mean (SD) duration of exposure to biosimilar rhGH was 3.66 years (2.39). A total of 16,628 adverse events (AEs) were reported in 3981 (54.1%) patients, most of which were mild/moderate. AEs suspected to be treatment related occurred in 8.3% of patients, most frequently headache (1.6%), injection-site pain (1.1%), or injection-site hematoma (1.1%). The incidence rate (IR) of type 2 diabetes mellitus was 0.11 per 1000 person-years (PY) across all patients, and 0.13 per 1000 PY in patients born SGA. The IR of newly diagnosed primary malignancies was 0.22 per 1000 PY across all patients. In the 6589 patients included in the effectiveness population, a sustained catch-up growth was observed across all indications. After 5 years of treatment, height SDS increased from baseline by a median (range) of +1.79 (-3.7 to 6.2) in treatment-naïve patients and +0.73 (-1.4 to 3.7) in pretreated patients.

Conclusion

This final analysis of the PATRO Children study indicates that biosimilar rhGH is well tolerated and effective in real-world clinical practice. These data are consistent with the well-characterized safety profile of rhGH treatment in pediatric patients.

Electrospinning technologies for the delivery of Biopharmaceuticals: Current status and future trends

This review provides an in-depth exploration of electrospinning techniques employed to produce micro- or nanofibres of biopharmaceuticals using polymeric solutions or melts with high-voltage electricity. Distinct from prior reviews, the current work narrows its focus on the recent developments and advanced applications in biopharmaceutical formulations. It begins with an overview of electrospinning principles, covering both solution and melt modes. Various methods for incorporating biopharmaceuticals into electrospun fibres, such as surface adsorption, blending, emulsion, co-axial, and high-throughput electrospinning, are elaborated. The review also surveys a wide array of biopharmaceuticals formulated through electrospinning, thereby identifying both opportunities and challenges in this emerging field. Moreover, it outlines the analytical techniques for characterizing electrospun fibres and discusses the legal and regulatory requirements for their production. This work aims to offer valuable insights into the evolving realm of electrospun biopharmaceutical delivery systems.

An overview of growth hormone therapy in pediatric cases documented in the Kabi International Growth Study (Pfizer International Growth Database)

The Kabi International Growth Study (KIGS) was first established in 1987 and is the largest pharmaco-epidemiological study of recombinant human growth hormone (rhGH). KIGS is aimed at evaluating long-term safety and treatment outcomes in pediatric subjects who received Genotropin rhGH therapy (Pfizer, New York, NY, USA) as prescribed by physicians in real-world clinical practice settings. KIGS data have been used to answer multiple research questions related to growth, growth prediction, and growth hormone treatment, leading to the publication of 129 peer-reviewed manuscripts and 24 biannual reports, outcomes from 10 expert meetings, and 3 books. The KIGS has shown that rhGH is safe and increases both the short-term height gain and adult height in patients with GH deficiency (GHD) and multiple other non-GHD conditions associated with short stature.

A Superlong-Acting Growth Hormone-Polypeptide Fusion for Growth Hormone Deficiency Treatment

Recombinant human growth hormone (rhGH) is clinically used to treat growth hormone deficiency (GHD). However, daily administration of rhGH is required due to its poor stability and short blood circulation, which causes pains and burdens as well as inconvenience to patients. In this study, a method for genetically fusing rhGH to a thermosensitive polymer of elastin-like polypeptide (ELP) is reported, using which the rhGH-ELP thermosensitive fusion protein can be purified by the thermosensitivity of ELP instead of chromatography. The ELP fusion not only drastically improves the stability of rhGH, but also enables the in situ formation of a sustained-release depot of rhGH-ELP upon subcutaneous (SC) injection, which exhibits gentle release with a platform-to-trough fluctuation in blood and a very long circulatory half-life of 594.6 h. In contrast, rhGH exhibits a peak-to-trough fluctuation in blood with a very short circulatory half-life of 0.7 h. As a result, a single subcutaneous injection of rhGH-ELP can consecutively promote the linear growth of rats and the development of major tissues and organs over 3 weeks without obvious side effects, whereas rhGH is required to be injected daily to achieve similar therapeutic results.

Growth Hormone Treatment for Non-GHD Disorders: Excitement Tempered by Biology

The success of growth hormone (GH) replacement in children with classical GH deficiency has led to excitement that other causes of short stature may benefit similarly. However, clinical experience has shown less consistent and generally less dramatic effects on adult height, perhaps not surprising in light of increased understanding of GH and growth plate biology. Nonetheless, clinical demand for GH treatment continues to grow. Upon the 20th anniversary of the US Food and Drug Administration's approval of GH treatment for idiopathic short stature, this review will consider the factors underlying the expansion of GH treatment, the biological mechanisms of GH action, the non-GH-deficient uses of GH as a height-promoting agent, biological constraints to GH action, and future directions.

Modifications of the GH Axis Reveal Unique Sexually Dimorphic Liver Signatures for Lcn13, Asns, Hamp2, Hao2, and Pgc1a

Growth hormone (GH) modifies liver gene transcription in a sexually dimorphic manner to meet liver metabolic demands related to sex; thus, GH dysregulation leads to sex-biased hepatic disease. We dissected the steps of the GH regulatory cascade modifying GH-dependent genes involved in metabolism, focusing on the male-predominant genes Lcn13, Asns, and Cyp7b1, and the female-predominant genes Hao2, Pgc1a, Hamp2, Cyp2a4, and Cyp2b9. We explored mRNA expression in 2 settings: (i) intact liver GH receptor (GHR) but altered GH and insulin-like growth factor 1 (IGF1) levels (NeuroDrd2KO, HiGH, aHepIGF1kd, and STAT5bCA mouse lines); and (ii) liver loss of GHR, with or without STAT5b reconstitution (aHepGHRkd, and aHepGHRkd + STAT5bCA). Lcn13 was downregulated in males in most models, while Asns and Cyp7b1 were decreased in males by low GH levels or action, or constant GH levels, but unexpectedly upregulated in both sexes by the loss of liver Igf1 or constitutive Stat5b expression. Hao, Cyp2a4, and Cyp2b9 were generally decreased in female mice with low GH levels or action (NeuroDrd2KO and/or aHepGHRkd mice) and increased in HiGH females, while in contrast, Pgc1a was increased in female NeuroDrd2KO but decreased in STAT5bCA and aHepIGF1kd females. Bioinformatic analysis of RNAseq from aHepGHRkd livers stressed the greater impact of GHR loss on wide gene expression in males and highlighted that GH modifies almost completely different gene signatures in each sex. Concordantly, we show that altering different steps of the GH cascade in the liver modified liver expression of Lcn13, Asns, Cyp7b1, Hao2, Hamp2, Pgc1a, Cyp2a4, and Cyp2b9 in a sex- and gene-specific manner.

Acromegaly: Overview and associated temporomandibular joint disorders

OBJECTIVE

To provide a review on acromegaly and its orofacial manifestations, with a focus on associated arthropathies and temporomandibular joint disorders (TMD).

METHODS

A review of current literature was performed through an electronic search of three databases: PubMed, ScienceDirect, and Google Scholar. The literature review was focused on the following topics of interest: etiology, diagnosis, and management of acromegaly, orofacial manifestations of acromegaly, acromegalic arthropathies, and acromegaly-associated TMD.

RESULTS

Acromegaly is a chronic multisystem condition in which excessive production of growth hormone in adults, most commonly caused by benign pituitary adenomas, leads to somatic overgrowth. Orofacial changes are considered hallmarks of the disease. It is important for dentists to recognize signs and symptoms of acromegaly, as this may help to achieve early diagnosis and improve overall disease prognosis. Acromegalic arthropathies typically involve large joints, however, the temporomandibular joints (TMJ) can be affected. TMD associated with acromegaly is under-recognized and poorly characterized in current literature.

CONCLUSION

In the appropriate clinical context, acromegaly should be considered as part of the differential diagnosis for patients presenting with TMD. Further studies are needed to better characterize the nature of TMD associated with acromegaly and to define the role of TMJ involvement in early diagnosis.

Crosstalk Between the Neuroendocrine System and Bone Homeostasis

The homeostasis of bone microenvironment is the foundation of bone health and comprises 2 concerted events: bone formation by osteoblasts and bone resorption by osteoclasts. In the early 21st century, leptin, an adipocytes-derived hormone, was found to affect bone homeostasis through hypothalamic relay and the sympathetic nervous system, involving neurotransmitters like serotonin and norepinephrine. This discovery has provided a new perspective regarding the synergistic effects of endocrine and nervous systems on skeletal homeostasis. Since then, more studies have been conducted, gradually uncovering the complex neuroendocrine regulation underlying bone homeostasis. Intriguingly, bone is also considered as an endocrine organ that can produce regulatory factors that in turn exert effects on neuroendocrine activities. After decades of exploration into bone regulation mechanisms, separate bioactive factors have been extensively investigated, whereas few studies have systematically shown a global view of bone homeostasis regulation. Therefore, we summarized the previously studied regulatory patterns from the nervous system and endocrine system to bone. This review will provide readers with a panoramic view of the intimate relationship between the neuroendocrine system and bone, compensating for the current understanding of the regulation patterns of bone homeostasis, and probably developing new therapeutic strategies for its related disorders.

In-depth mass spectrometry analysis of rhGH administration altered energy metabolism and steroidogenesis

Growth hormone, as a proteohormone, is primarily known of its dramatic effect on longitudinal growth. Recombinant DNA technology has provided a safe, abundant and comparatively cheap supply of human GH for growth hormone-deficient individuals. However, many healthy subjects, especially athletics, administrate GH for enhanced athletic performance or strength. A better and more comprehensive understanding of rhGH effect in healthy individuals is urgent and essential. In this study, we recruited 14 healthy young male and injected rhGH once. Untargeted LC-MS metabolomics profiling of serum and urine was performed before and after the rhGH injection. The GH-induced dysregulation of energy related pathways, such as amino acid metabolism, nucleotide metabolism, glycolysis and TCA cycle, was revealed. Moreover, individuals supplemented with micro-doses of rhGH exhibited significantly changed urinary steroidal profiles, suggesting a role of rhGH in both energy metabolism and steroidogenesis. We expect that our results will be helpful to provide new evidence on the effects of rhGH injection and provide potential biomarkers for rhGH administration.

[Diagnostic significance and considerations of growth hormone stimulation testing and insulin-like growth factor 1 in growth hormone deficiency]

The growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis is an essential component of the hypothalamic-pituitary growth hormone axis and plays a crucial role in childhood growth and development. Disruptions and abnormalities in the GH/IGF-1 signaling pathway and its pathways typically manifest as short stature in children. Children with short stature often undergo GH stimulation testing and IGF-1 level measurements to differentiate growth hormone deficiency (GHD) from other causes of growth delay. This article aims to analyze and elucidate the values of GH stimulation testing and IGF-1 measurement, providing reference for the diagnosis of GHD in children.

2022 Cannon lecture: an ode to signal transduction: how the growth hormone pathway revealed insight into height, malignancy, and obesity

Walter Cannon was a highly regarded American neurologist and physiologist with extremely broad interests. In the tradition of Cannon and his broad interests, we discuss our laboratory's multifaceted work in signal transduction over the past 40+ years. We show how our questioning of how growth hormone (GH) in the blood communicates with cells throughout the body to promote body growth and regulate body metabolism led to insight into not only body height but also important regulators of malignancy and body weight. Highlights include finding that 1) A critical initiating step in GH signal transduction is GH activating the GH receptor-associated tyrosine kinase JAK2; 2) GH activation of JAK2 leads to activation of a number of signaling proteins, including STAT transcription factors; 3) JAK2 is autophosphorylated on multiple tyrosines that regulate the activity of JAK2 and recruit signaling proteins to GH/GH receptor/JAK2 complexes; 4) Constitutively activated STAT proteins are associated with cancer; 5) GH activation of JAK2 recruits the adapter protein SH2B1 to GH/GH receptor/JAK2 complexes where it facilitates GH regulation of the actin cytoskeleton and motility; and 6) SH2B1 is recruited to other receptors in the brain, where it enhances satiety, most likely in part by regulating leptin action and neuronal connections of appetite-regulating neurons. These findings have led to increased understanding of how GH functions, as well as therapeutic interventions for certain cancer and obese individuals, thereby reinforcing the great importance of supporting basic research since one never knows ahead of time what important insight it can provide.

Involvement of Sirtuin 1 in the Growth Hormone/Insulin-like Growth Factor 1 Signal Transduction and Its Impact on Growth Processes in Children

The regulation of growth processes in children depends on the synthesis of growth hormone (GH) and insulin-like growth factor 1 (IGF-1). Insulin-like growth factor 1, which is mainly secreted in the liver in response to GH, is the main peripheral mediator of GH action. Newly discovered factors regulating GH secretion and its effects are being studied recently. One of them is sirtuin 1 (SIRT1). This NAD+-dependent deacetylase, by modulating the JAK2/STAT pathway, is involved in the transduction of the GH signal in hepatocytes, leading to the synthesis of IGF-1. In addition, it participates in the regulation of the synthesis of GHRH in the hypothalamus and GH in the somatotropic cells. SIRT1 is suggested to be involved in growth plate chondrogenesis and longitudinal bone growth as it has a positive effect on the epiphyseal growth plate. SIRT1 is also implicated in various cellular processes, including metabolism, cell cycle regulation, apoptosis, oxidative stress response, and DNA repair. Thus, its expression varies depending on the different metabolic states. During malnutrition, SIRT1 blocks GH signal transduction in hepatocytes to reduce the IGF-1 secretion and prevent hypoglycemia (i.e., it causes transient GH resistance). In this review, we focused on the influence of SIRT1 on GH signal transduction and the implications that may arise for growth processes in children.

Insulin-like growth factor (IGF) performance in ovarian function and applications in reproductive biotechnologies

The role of the insulin-like growth factor (IGF) system has attracted close attention. The activity of IGF binding proteins (IGFBPs) within the ovary has not been fully elucidated to date. These proteins bind to IGF with an equal, or greater, affinity than to the IGF1 receptor, thus being in the main position to regulate IGF signalling, in addition to extending the half-life of IGFs within the bloodstream and promoting IGF storage in specific tissue niches. IGF1 has an important part in cell proliferation, differentiation and apoptosis. Considering the importance of IGFs in oocyte maturation, this review sought to elucidate aspects including: IGF production mechanisms; constituent members of their family and their respective functions; the role that these factors play during folliculogenesis, together with their functions during oocyte maturation and apoptosis, and their performance during luteal development. This review also explores the role of IGFs in biotechnological applications, focusing specifically on animal genetic gain.

Spectroscopic analysis of recombinant human growth hormone in the presence of sucrose and trehalose

Recombinant human growth hormone (rhGH) is a therapeutic protein, associated with various human diseases, such as growth hormone deficiency. One of the interesting issues in the formulation of therapeutic proteins is excipients like disaccharides. In the current study, we try to compare the effect of sucrose and trehalose on the structure of rhGH in the liquid state at 25°C and 55°C. We use spectroscopic techniques including intrinsic and extrinsic fluorescence, Fourier-transform infrared (FTIR), circular dichroism (CD), dynamic light scattering (DLS), and time-resolved fluorescence. FTIR shows a slight change in the secondary structure of rhGH in presence of the sugars as sucrose is more effective than trehalose. Fluorescence investigations also confirm the enhancements of folding of rhGH and fluorescein isothiocyanate (FITC)-rhGH in presence of sucrose (1.5-fold more than trehalose). Also, we studied sucrose's effect on the rete of aggregation of rhGH using spectroscopy of Congo red, and fluorescence imaging of thioflavin T (ThT)-treated samples. It can be suggested that sucrose facilitates the amyloid formation of rhGH during 20 days of incubation at 37°C. This study will help to understand the growth hormone structural behavior in the liquid state in the presence of sucrose and trehalose in vitro.

Role of Growth Hormone in Adipose Tissue Insulin Resistance Amelioration After Bariatric Surgery in Adults with Obesity

Background: Bariatric surgery has a significant effect on weight loss and improves adipose tissue insulin resistance (adipose-IR); however, the underlying mechanism remains unclear. This study aimed to investigate the effect of growth hormone (GH) on adipose-IR improvement after bariatric surgery in patients with obesity. Methods: A prospective cohort study with 1-year follow-up was conducted in the China-Japan Friendship Hospital. Pre- and postoperative variables, including the body mass index (BMI), glucose and lipid metabolic indicators, and the adipose-IR index, were collected and analyzed at baseline and 3, 6, and 12 months after surgery in patients with obesity. Results: In total, seventy-two patients, including 25 males and 47 females, were included in the analysis. Furthermore, bariatric surgery resulted in a sharp decline in BMI (kg/m2) (from 39.45 ± 0.51 to 32.00 ± 0.63 at 3 months, 28.73 ± 0.56 at 6 months, and 27.25 ± 0.68 at 12 months) and adipose-IR index (mmol/L × pmol/L) (from 163.8 ± 9.38 to 94.39 ± 16.63, 43.71 ± 5.13, and 27.92 ± 2.67) and an increase in GH (ng/mL) (from 0.16 ± 0.02 to 0.61 ± 0.10, 1.02 ± 0.19, and 0.89 ± 0.20). Partial correlation analyses were performed with reduced BMI as a control, and elevated GH levels (ΔGH) were found to be positively correlated with reduced adipose-IR (absolute value of Δadipose-IR) index at 3 months (r = 0.413, P = 0.005), 6 months (r = 0.432, P < 0.001), and 12 months (r = 0.375, P = 0.031) after bariatric surgery. Conclusions: Bariatric surgery induces GH elevation and adipose-IR amelioration in patients with obesity. GH might be a potential metabolic regulator associated with adipose-IR improvement in patients with obesity after bariatric surgery.

Prevalence of refractoriness when testing growth hormone levels in children

OBJECTIVE

Late night spontaneous growth hormone (GH) pulses may influence the pituitary GH response to provocation tests. We evaluated GH response during arginine-insulin-tolerance test (AITT) after a GH peak during a short spontaneous nocturnal profile (SSNP) in children with short stature or low growth velocity.

DESIGN

Using SSNP and subsequent AITT, we examined 257 children 4-18 years old (138 (53.7%) males) recruited from three hospitals. Medical records were reviewed retrospectively. Refractory children were defined as a GH peak ≥7 μg/L during SSNP but no GH peak ≥7 μg/L during AITT.

RESULTS

In total, 201/257 children had a GH peak ≥7 μg/L at SSNP and/or AITT. Of these, 21.9% were refractory. The proportion of males (p = 0.033) and body mass index (BMI) standard deviation score (SDS) (p = 0.037) were higher in the refractory group than in children with a GH peak ≥7 μg/L during AITT. The median period between last GH peak ≥7 μg/L during SSNP and GHmax at AITT was 210 (30-390) minutes. The GHmax at AITT occurred 30 min earlier for children without a peak ≥7 μg/L during the SSNP (p = 0.004). The number of refractoriness differed somewhat between the hospitals (p = 0.025).

CONCLUSIONS

Many children with short stature were refractory at testing; among them we found few clinical characteristics. Refractoriness might be influenced by some differences in procedure, but needs to be considered when evaluating GH response in children.

Growth Hormone Injection Log Analysis with Electronic Injection Device for Qualifying Adherence to Low-Irritant Formulation and Exploring Influential Factors on Adherence

Introduction

Although the treatment success of long-term growth hormone therapy (GHT) is dependent on maintaining patients' adherence to treatment, marked variations in adherence levels among children with GHT (eg, 7-71% nonadherence) have been reported. Barriers to or promoters of GHT adherence have been discussed and investigated, and digital health technologies, such as electronic GH injection devices, may have the potential to assess adherence to GHT more accurately. Thus, we conducted a multicenter, retrospective cohort study using GH injection log analysis of an electronic GH device, GROWJECTOR®L, to qualify adherence and explore the factors influencing adherence.

Methods

This study enrolled 41 patients (median[range] age, 5.8[3.0 ~ 17.0] years) with short stature from nine Japanese medical institutions. The injection log data (12-48 weeks) were read by smartphones and collected into the data center through a cloud server.

Results

Although cumulative adherence rates remained higher than 95% throughout the observation period, five (12.2%) patients had low adherence (<85%). Subsequently, subgroup and logistic regression analyses for exploring factors affecting adherence revealed that self-selection of GH device and irregular injection schedule (ie, frequent injections after midnight) significantly affected adherence rate (p=0.034 and 0.048, respectively). In addition, higher rates of irregular injections significantly affected low adherence (median[range], 11.26[0.79 ~ 30.50]% vs 0.26[0.00 ~ 33.33]%, p = 0.029).

Discussion

Our study indicated that injection log analysis using an electronic GH device could detect irregular injection schedules due to a night owl or disturbance in lifetime rhythm affecting low adherence and had significant potential to encourage collaborative monitoring of adherence with healthcare providers and patients themselves/caregivers, along with growing autonomy and shared decision-making. Our study suggests the significance of narrative and personal approaches to adherence of patients with GHT and the usefulness of digital devices for such an approach and for removing various barriers to patient autonomy, leading to improvement and maintenance of adherence.

Effects on the Hypothalamo-Pituitary Axis in Patients with CNS or Head and Neck Tumors following Radiotherapy

BACKGROUND

Knowledge about the precise effects of radiotherapy on hypothalamo-pituitary functions is limited. Reduction of side effects is a major goal of advanced radiotherapy modalities. We assessed strategies for monitoring and replacement of hormone deficiencies in irradiated patients.

METHODS

A search strategy was systematically conducted on PubMed®. Additional articles were retrieved to describe endocrine mechanisms.

RESULTS

45 studies were evaluated from 2000 to 2022. They were predominantly retrospective and highly heterogeneous concerning patient numbers, tumor types, radiotherapy technique and follow-up. Endocrine deficiencies occurred in about 40% of patients within a median follow-up of 5.6 years without a clear difference between radiotherapy modalities. Somatotropic and thyrotropic axes were, respectively, the most and least radiosensitive.

CONCLUSIONS

Current pituitary gland dose constraints may underestimate radiation-induced endocrine deficiencies, thus impairing quality of life. Little difference might be expected between radiation techniques for PG tumors. For non-PG tumors, dose constraints should be applied more systematically.

KLF13 Regulates the Activity of the GH-Induced JAK/STAT Signaling by Targeting Genes Involved in the Pathway

The Krüppel-like factor 13 (KLF13) has emerged as an important transcription factor involved in essential processes of the central nervous system (CNS). It predominantly functions as a transcriptional repressor, impacting the activity of several signaling pathways with essential roles in the CNS, including the JAK/STAT pathway, which is the canonical mediator of growth hormone (GH) signaling. It is now recognized that GH has important actions as a neurotrophic factor. Therefore, we analyzed the effects of KLF13 on the activity of the JAK/STAT signaling pathway in the hippocampus-derived cell line HT22. Results showed that KLF13 directly regulates the expression of several genes involved in the JAK-STAT pathway, including Jak1, Jak2, Jak3, and Socs1, by associating with their proximal gene promoters. In addition, it was found that in KLF13-deficient HT22 neurons, the expression of Jak1, Stat3, Socs1, Socs3, and Igf1 was dysregulated, exhibiting mRNA levels that went up to 7-fold higher than the control cell line. KLF13 displayed a differential effect on the GH-induced JAK/STAT pathway activity, decreasing the STAT3 branch while enhancing the STAT5 branch. In KLF13-deficient HT22 cells, the activity of the STAT3 branch was enhanced, mediating the GH-dependent augmented expression of the JAK/STAT output genes Socs1, Socs3, Igf1, and Bdnf. Furthermore, GH treatment increased both the nuclear content of KLF13 and Klf13 mRNA levels, suggesting that KLF13 could be part of the mechanisms that maintain the homeostatic state of this pathway. These findings support the notion that KLF13 is a regulator of JAK/STAT activity.

Intrathymic somatotropic circuitry: consequences upon thymus involution

Growth hormone (GH) is a classic pituitary-derived hormone crucial to body growth and metabolism. In the pituitary gland, GH production is stimulated by GH-releasing hormone and inhibited by somatostatin. GH secretion can also be induced by other peptides, such as ghrelin, which interacts with receptors present in somatotropic cells. It is well established that GH acts directly on target cells or indirectly by stimulating the production of insulin-like growth factors (IGFs), particularly IGF-1. Notably, such somatotropic circuitry is also involved in the development and function of immune cells and organs, including the thymus. Interestingly, GH, IGF-1, ghrelin, and somatostatin are expressed in the thymus in the lymphoid and microenvironmental compartments, where they stimulate the secretion of soluble factors and extracellular matrix molecules involved in the general process of intrathymic T-cell development. Clinical trials in which GH was used to treat immunocompromised patients successfully recovered thymic function. Additionally, there is evidence that the reduction in the function of the somatotropic axis is associated with age-related thymus atrophy. Treatment with GH, IGF-1 or ghrelin can restore thymopoiesis of old animals, thus in keeping with a clinical study showing that treatment with GH, associated with metformin and dehydroepiandrosterone, could induce thymus regeneration in healthy aged individuals. In conclusion, the molecules of the somatotrophic axis can be envisioned as potential therapeutic targets for thymus regeneration in age-related or pathological thymus involution.

Local GHR roles in regulation of mitochondrial function through mitochondrial biogenesis during myoblast differentiation

BACKGROUND

Myoblast differentiation requires metabolic reprogramming driven by increased mitochondrial biogenesis and oxidative phosphorylation. The canonical GH-GHR-IGFs axis in liver exhibits a great complexity in response to somatic growth. However, the underlying mechanism of whether local GHR acts as a control valve to regulate mitochondrial function through mitochondrial biogenesis during myoblast differentiation remains unknown.

METHODS

We manipulated the GHR expression in chicken primary myoblast to investigate its roles in mitochondrial biogenesis and function during myoblast differentiation.

RESULTS

We reported that GHR is induced during myoblast differentiation. Local GHR promoted mitochondrial biogenesis during myoblast differentiation, as determined by the fluorescence intensity of Mito-Tracker Green staining and MitoTimer reporter system, the expression of mitochondrial biogenesis markers (PGC1α, NRF1, TFAM) and mtDNA encoded gene (ND1, CYTB, COX1, ATP6), as well as mtDNA content. Consistently, local GHR enhanced mitochondrial function during myoblast differentiation, as determined by the oxygen consumption rate, mitochondrial membrane potential, ATP level and ROS production. We next revealed that the regulation of mitochondrial biogenesis and function by GHR depends on IGF1. In terms of the underlying mechanism, we demonstrated that IGF1 regulates mitochondrial biogenesis via PI3K/AKT/CREB pathway. Additionally, GHR knockdown repressed myoblast differentiation.

CONCLUSIONS

In conclusion, our data corroborate that local GHR acts as a control valve to enhance mitochondrial function by promoting mitochondrial biogenesis via IGF1-PI3K/AKT/CREB pathway during myoblast differentiation. Video Abstract.

The Stanniocalcin-PAPP-A-IGFBP-IGF Axis

The pappalysin metalloproteinases, PAPP-A and PAPP-A2, have emerged as highly specific proteolytic enzymes involved in the regulation of insulin-like growth factor (IGF) signaling. The only known pappalysin substrates are a subset of the IGF binding proteins (IGFBPs), which bind IGF-I or IGF-II with high affinity to antagonize receptor binding. Thus, by cleaving IGFBPs, the pappalysins have the potential to increase IGF bioactivity and hence promote IGF signaling. This is relevant both in systemic and local IGF regulation, in normal and several pathophysiological conditions. Stanniocalcin-1 and -2 were recently found to be potent pappalysin inhibitors, thus comprising the missing components of a complete proteolytic system, the stanniocalcin-PAPP-A-IGFBP-IGF axis. Here, we provide the biological context necessary for understanding the properties of this molecular network, and we review biochemical data, animal experiments, clinical data, and genetic data supporting the physiological operation of this branch as an important part of the IGF system. However, although in vivo data clearly illustrate its power, it is a challenge to understand its subtle operation, for example, multiple equilibria and inhibitory kinetics may determine how, where, and when the IGF receptor is stimulated. In addition, literally all of the regulatory proteins have suspected or known activities that are not directly related to IGF signaling. How such activities may integrate with IGF signaling is also important to address in the future.

Exploring the Therapeutic Potential of Targeting GH and IGF-1 in the Management of Obesity: Insights from the Interplay between These Hormones and Metabolism

Obesity is a growing public health problem worldwide, and GH and IGF-1 have been studied as potential therapeutic targets for managing this condition. This review article aims to provide a comprehensive view of the interplay between GH and IGF-1 and metabolism within the context of obesity. We conducted a systematic review of the literature that was published from 1993 to 2023, using MEDLINE, Embase, and Cochrane databases. We included studies that investigated the effects of GH and IGF-1 on adipose tissue metabolism, energy balance, and weight regulation in humans and animals. Our review highlights the physiological functions of GH and IGF-1 in adipose tissue metabolism, including lipolysis and adipogenesis. We also discuss the potential mechanisms underlying the effects of these hormones on energy balance, such as their influence on insulin sensitivity and appetite regulation. Additionally, we summarize the current evidence regarding the efficacy and safety of GH and IGF-1 as therapeutic targets for managing obesity, including in pharmacological interventions and hormone replacement therapy. Finally, we address the challenges and limitations of targeting GH and IGF-1 in obesity management.

Sustained secretion of human growth hormone from TheraCyte devices encapsulated with PiggyBac-engineered retinal pigment epithelium cells

Growth hormone (GH) deficiency is characterized by impaired growth and development, and is currently treated by repeated administration of recombinant human GH (hGH). Encapsulated cell therapy (ECT) may offer a less demanding treatment-strategy for long-term production and release of GH into circulation. We used PiggyBac-based (PB) transposon delivery for engineering retinal pigment epithelial cells (ARPE-19), and tested a series of viral and non-viral promoters as well as codon-optimization to enhance transgene expression. Engineered cells were loaded into TheraCyte macrocapsules and secretion was followed in vitro and in vivo. The cytomegalovirus (CMV) promoter supports strong and persistent transgene expression, and we achieved clonal cell lines secreting over 6 µg hGH/10⁶ cells/day. Codon-optimization of the hGH gene did not improve secretion. ARPE-19 cells endured encapsulation in TheraCyte devices, and resulted in steady hormone release for at least 60 days in vitro. A short-term pilot experiment in immunodeficient SCID mice demonstrated low systemic levels of hGH from a single 40 µL capsule implanted subcutaneously. No significant increase in weight increase or systemic hGH was detected after 23 days in the GH-deficient lit/SCID mouse model using 4.5 µL capsules loaded with the highest secreting clone of ARPE-19 cells. Our results demonstrate that PB-mediated engineering of ARPE-19 is an efficient way to generate hormone secreting cell lines compatible with macroencapsulation, and our CMV-driven expression cassette allows for identification of clones with high level and long-term secretory activity without addition of insulator elements. Our results pave the way for further in vivo studies of encapsulated cell therapy.

Growth Hormone Deficiency following Traumatic Brain Injury in Pediatric and Adolescent Patients: Presentation, Treatment, and Challenges of Transitioning from Pediatric to Adult Services

Traumatic brain injury (TBI) is increasingly recognized, with an incidence of approximately 110 per 100,000 in pediatric populations and 618 per 100,000 in adolescent and adult populations. TBI often leads to cognitive, behavioral, and physical consequences, including endocrinopathies. Deficiencies in anterior pituitary hormones (e.g., adrenocorticotropic hormone, thyroid-stimulating hormone, gonadotropins, and growth hormone [GH]) can negatively impact health outcomes and quality of life post-TBI. This review focuses on GH deficiency (GHD), the most common post-TBI pituitary hormone deficiency. GHD is associated with abnormal body composition, lipid metabolism, bone mineral density, executive brain functions, behavior, and height outcomes in pediatric, adolescent, and transition-age patients. Despite its relatively frequent occurrence, post-TBI GHD has not been well studied in these patients; hence, diagnostic and treatment recommendations are limited. Here, we examine the occurrence and diagnosis of TBI, retrospectively analyze post-TBI hypopituitarism and GHD prevalence rates in pediatric and adolescent patients, and discuss appropriate GHD testing strategies and GH dosage recommendations for these patients. We place particular emphasis on the ways in which testing and dosage recommendations may change during the transition phase. We conclude with a review of the challenges faced by transition-age patients and how these may be addressed to improve access to adequate healthcare. Little information is currently available to help guide patients with TBI and GHD through the transition phase and there is a risk of interrupted care; therefore, a strength of this review is its emphasis on this critical period in a patient's healthcare journey.

Growth Hormone Signaling in Liver Diseases: Therapeutic Potentials and Controversies

Growth hormone (GH) and downstream insulin-like growth factor 1 (IGF1) signaling mediate growth and metabolism. GH deficiency causes short stature or dwarfism, and excess GH causes acromegaly. Although the association of GH/IGF1 signaling with liver diseases has been suggested previously, current studies are controversial and the functional roles of GH/IGF1 signaling are still undefined. GH supplementation therapy showed promising therapeutic effects in some patients, such as non-alcoholic fatty liver disease, but inhibition of GH signaling may be beneficial for other liver diseases, such as hepatocellular carcinoma. The functional roles of GH/IGF1 signaling and the effects of agonists/antagonists targeting this signaling may differ depending on the liver injury or animal models. This review summarizes current controversial studies of GH/IGF1 signaling in liver diseases and discusses therapeutic potentials of GH therapy.

Comparison of two prediction models in a clinical setting to predict growth in prepubertal children on recombinant growth hormone

OBJECTIVE

Prediction models that calculate the growth response in children on recombinant growth hormone (GH) have shown to be helpful tools in deciding who should start treatment, as identifying GH deficiency can be a challenge. The aim of the study is to compare two prediction models; the KIGS (Pfizer International Growth Study) prediction models which are more accessible and the Gothenburg model which has previously been clinically validated.

DESIGN

All prepubertal patients who commenced GH treatment at Queen Silvia Children's Hospital in Gothenburg during a 13-year-period were candidates for the study. Children were excluded if suspected syndrome, malignant disease, chronic disease, or poor adherence to treatment were found. The KIGS model and the Gothenburg model were used to make predictions. Data was obtained from medical charts for the period from birth to the end of the first year of treatment. The predicted height outcome was compared against observed.

RESULTS

The study included 123 prepubertal children (76 males). The average age at treatment start and standard deviation (SD) was 5.7 (1.8) years. Correlation analyses were performed between predicted growth by both the Gothenburg and KIGS models versus the first year observed growth response showing strong correlations of r = 0.990 and r = 0.991 respectively with studentized residuals of 0.10 (0.81) for the Gothenburg model and 0.03 (0.96) for the KIGS model.

CONCLUSION

We found that both the Gothenburg model and the KIGS model are equivalent when applying to our clinical cohort. Both models are very precise, hence it is encouraged to use either based on accessibility for the clinic.

Long-Term Safety of Growth Hormone Deficiency Treatment in Cancer and Sellar Tumors Adult Survivors: Is There a Role of GH Therapy on the Neoplastic Risk?

Experimental studies support the hypothesis that GH/IGF-1 status may influence neoplastic tissue growth. Epidemiological studies suggest a link between GH/IGF-1 status and cancer risk. However, several studies regarding GH replacement safety in childhood cancer survivors do not show a prevalence excess of de novo cancers, and several reports on children and adults treated with GH have not shown an increase in observed cancer risk in these patients. The aim of this review is to provide an at-a-glance overview and the state of the art of long-term effects of GH replacement on neoplastic risk in adults with growth hormone deficiency who have survived cancer and sellar tumors.