Unveiling terahertz wave stress effects and mechanisms in Pinellia ternata: Challenges, insights, and future directions.

This review aims to elucidate the intricate effects and mechanisms of terahertz (THz) wave stress on Pinellia ternata, providing valuable insights into plant responses. The primary objective is to highlight the imperative for future research dedicated to comprehending THz wave impacts across plant structures, with a specific focus on the molecular intricacies governing root system structure and function, from shoots to roots. Notably, this review highlights the accelerated plant growth induced by THz waves, especially in conjunction with other environmental stressors, and the subsequent alterations in cellular homeostasis, resulting in the generation of reactive oxygen species (ROS) and an increase in brassinosteroids. Brassinosteroids are explored for their dual role as toxic by-products of stress metabolism and vital signal transduction molecules in plant responses to abiotic stresses. The paper further investigates the spatio-temporal regulation and long-distance transport of phytohormones, including growth hormone, cytokinin, and abscisic acid (ABA), which significantly influence the growth and development of P. ternata under THz wave stress. With a comprehensive review of Reactive oxygen species (ROS) and Brassinosteroid Insensitive (BRI) homeostasis and signalling under THz wave stress, the article elucidates the current understanding of BRI involvement in stress perception, stress signalling, and domestication response regulation. Additionally, it underscores the importance of spatio-temporal regulation and long-distance transport of key plant hormones, such as growth hormone, cytokinin, and ABA, in determining root growth and development under THz wave stress. The study of how plants perceive and respond to environmental stresses holds fundamental biological significance, and enhancing plant stress tolerance is crucial for promoting sustainable agricultural practices and mitigating the environmental burdens associated with low-tolerance crop cultivation.

Impact of Growth Hormone on Microglial and Astrocytic Function.

The role of growth hormone (GH) in the central nervous system (CNS) involves neuroprotection, neuroregeneration, formation of axonal projections, control of cognition, and regulation of metabolism. As GH induces insulin-like growth factor-1 (IGF-1) expression in many tissues, differentiating the specific functions of GH and IGF-1 in the organism is a significant challenge. The actions of GH and IGF-1 in neurons have been more extensively studied than their functions in nonneuronal cells (e.g., microglial cells). Glial cells are fundamentally important to CNS function. Microglia, astrocytes, oligodendrocytes, and tanycytes are essential to the survival, differentiation, and proliferation of neurons. As the interaction of the GH/IGF-1 axis with glial cells merits further exploration, our objective for this review was to summarize and discuss the available literature regarding the genuine effects of GH on glial cells, seeking to differentiate them from the role played by IGF-1 action whenever possible.

Effect of treatment with growth hormone on body composition and metabolic profile of short children born small for gestational age.

OBJECTIVE: To assess the effect of recombinant growth hormone (rGH) on body composition and metabolic profile of prepubertal short children born small for gestational age (SGA) before and after 18 months of treatment. METHODS: It is a clinical, non-randomized, and paired study. Children born SGA, with birth weight and/or length <-2 standard deviations (SD) for gestational age and sex, prepubertal, born at full term, of both genders, with the indication for treatment with rGH were included. The intervention was performed with biosynthetic rGH at doses ranging from 0.03 to 0.05 mg/kg/day, administered subcutaneously, once a day at bedtime. Total lean mass (LM) and total fat mass (FM) were carried out using dual-energy X-ray absorptiometry (DXA), and the metabolic profile was assessed for insulin, glycemia, IGF-1 levels and lipid profile. RESULTS: Twelve patients (nine girls, 8.17±2.39 y) were evaluated; three patients dropped out of the study. There was an increase of LM adjusted for length (LMI) (p=0.008), LMI standard deviation score (SDS) adjusted for age and sex (p=0.007), and total LM (p<0.001). The percentage of body fat (BF%) and abdominal fat (AF) remained unaltered in relation to the beginning of treatment. Among the metabolic variables, blood glucose remained within normal levels, and there was a reduction in the number of participants with altered cholesterol (p=0.023). CONCLUSIONS: The effect of rGH treatment was higher on LM than in FM, with increased LM adjusted for length and standardized for age and sex. Glycemia remained within the normal limits, and there was a decreased number of children with total cholesterol above the recommended levels.

Effects of two alternative plasticizers on the growth hormone-related endocrine system, neurodevelopment, and oxidative stress of zebrafish larvae.

In response to the restriction of phthalate plasticizers, acetyl tributyl citrate (ATBC) and acetyl triethyl citrate (ATEC) have been used in medical devices and food packaging. In the present study, the effects of ATBC and ATEC on the development, behavior, growth hormone (GH)-related endocrine system, neurotransmitters, and oxidative stress of zebrafish embryo or larvae were investigated. After exposure of zebrafish to ATBC and ATEC (0, 0.03, 0.3, 3, 30, and 300 µg/L) for 96 h, developmental toxicity, behavioral changes under light/dark condition, changes in hormones and genes involved in GH/insulin-like growth factors (IGFs) axis, changes in hormone, enzyme, and genes related to neurodevelopment, antioxidant enzymes activities were determined. Larvae exposed to 30 or 300 µg/L ATBC showed significant reductions in body length and moving distance and speed, whereas no significant effects on development and locomotor behavior were observed in larvae exposed to ATEC. The contents of GH and IGF-I were significantly reduced in larvae exposed to 3, 30, and 300 µg/L ATBC. Hormonal changes in fish exposed to ATBC are well supported by regulation of genes related to GH (gh1) and the activity of IGF-I (igf1). In fish exposed to ATBC, reduced acetylcholinesterase activity and down-regulation of genes related to the central nervous system development (ache, gap43, mbpa, and syn21) were observed. ATBC increased the production of reactive oxygen species and the levels of superoxide dismutase, catalase, and glutathione peroxidase. Notably, pre-treatment with the classic antioxidant N-acetylcysteine alleviated ATBC-induced GH-related endocrine disruption and neurotoxicity. Our observations showed that exposure to low levels of ATBC could disturb the regulatory systems of GH/IGFs axis and neurobehavior, ultimately leading to developmental inhibition and hypoactivity, and that increased oxidative stress plays a major role in these toxicities.

Beyond Growth Hormone: Association of Short Stature Types and Growth Hormones With Scoliosis.

STUDY DESIGN: Cross-sectional and retrospective cohort study. OBJECTIVE: We investigated the effect of 3 types of short stature [partial growth hormone deficiency (GHD), GHD, and idiopathic short stature (ISS)] and recombinant human growth hormone (rhGH) therapy on scoliosis. SUMMARY OF BACKGROUND DATA: In short stature, rhGH is widely used and the concentration of growth hormone varies among types. The epidemiologic characteristics of scoliosis and the role of rhGH in scoliosis remain unclear. PATIENTS AND METHODS: A cross-sectional study was conducted among 3896 patients with short stature (partial GHD, GHD, and ISS), and a 1:1 age and sex-matched control group with preexisting whole-spine radiographs. The cohort study included 2605 subjects who underwent radiography more than twice to assess scoliosis development, progression, and the need for bracing and surgery. Adjusted logistic regression was used to assess differences in the prevalence of scoliosis among patients with partial GHD, GHD, ISS, and controls. The Kaplan-Meier method was used to analyze the time course of scoliosis development and progression. Cox regression was applied to assess the independent factors related to scoliosis development and progression. Mendelian randomization analyses were also performed. RESULTS: Compared with controls, patients with short stature had a higher incidence of scoliosis (34.47% in partial GHD, 31.85% in GHD, 32.94% in ISS vs . 8.83% in control, P < 0.001), a higher risk of scoliosis development [hazard ratio (HR) = 1.964 in partial GHD, P < 0.001; HR = 1.881 in GHD, P = 0.001; HR = 1.706 in ISS, P = 0.001), but not a higher risk of progression, brace, or surgery. Among the 3 types of short stature, there were no differences in the incidence, development, and progression of scoliosis or the need for bracing or surgery. RhGH treatment increased the risk of scoliosis development in each short-stature group (HR = 2.673 in partial GHD, P < 0.001; HR = 1.924 in GHD, P = 0.049; HR = 1.564 in ISS, P = 0.004). Vitamin D supplementation was protective against scoliosis development (HR = 0.456 in partial GHD, P = 0.003; HR = 0.42 in GHD, P = 0.013; HR = 0.838 in ISS, P = 0.257). CONCLUSIONS: More attention should be paid to the spinal curve in patients with partial GHD, GHD, or ISS. For short stature treated with rhGH, the risk of scoliosis development was increased. Vitamin D supplementation may be beneficial for prevention. LEVEL OF EVIDENCE: Level III.

Interdisciplinary gene manipulation, molecular cloning, and recombinant expression of modified human growth hormone isoform-1 in E. coli system.

BACKGROUND: Growth hormone (GH) is a hormone that promotes growth, cell reproduction, and cell restoration in humans and animals. OBJECTIVES: Production of recombinant human growth hormone (rhGH) in Escherichia coli (E. coli) and assessment of its characteristics and proliferation stimulatory activity. METHODS: The hGH gene was cloned into a pET 3a expression vector and transformed into a competent E. coli cell. The refolded hGH was purified, Western blot and batch fermentation were performed. Cell cytotoxicity was tested on Vero cells, and MALDI-TOF and Nano-LC-ESI MS/MS were used for protein and target peptide analysis. RESULTS: Induced rhGH was purified with a concentration of 511.9 mg/ml. Western blot confirmed the molecular identity of rhGH, showing a single 22 kDa band. The bacterial growth at OD600 after 24 h in batch fermentation was 9.78 ± 0.26, and wet cell weight (WCWg/L) was 15.2 ± 0.32. Purified rhGH activity on Vero cells was 0.535 IU/mg. LC-MS/MS analysis revealed a score of 70.51 % and coverage of 60.37 %. CONCLUSION: Biologically active native rhGH protein was successfully expressed in the Prokaryotic system. Our goal is to increase its production on a pilot level in the native form at a high activity effect identical to isoform 1.

Evaluation of the anticonvulsant and neuroprotective effect of intracerebral administration of growth hormone in rats.

INTRODUCTION: The growth hormone (GH) has been reported as a crucial neuronal survival factor in the hippocampus against insults of diverse nature. Status epilepticus (SE) is a prolonged seizure that produces extensive neuronal cell death. The goal of this study was to evaluate the effect of intracerebroventricular administration of GH on seizure severity and SE-induced hippocampal neurodegeneration. METHODOLOGY: Adult male rats were implanted with a guide cannula in the left ventricle and different amounts of GH (70, 120 or 220ng/3µl) were microinjected for 5 days; artificial cerebrospinal fluid was used as the vehicle. Seizures were induced by the lithium-pilocarpine model (3mEq/kg LiCl and 30mg/kg pilocarpine hydrochloride) one day after the last GH administration. Neuronal injury was assessed by Fluoro-Jade B (F-JB) staining. RESULTS: Rats injected with 120ng of GH did not had SE after 30mg/kg pilocarpine, they required a higher number of pilocarpine injections to develop SE than the rats pretreated with the vehicle, 70ng or 220ng GH. Prefrontal and parietal cortex EEG recordings confirmed that latency to generalized seizures and SE was also significantly higher in the 120ng group when compared with all the experimental groups. FJ-B positive cells were detected in the hippocampus after SE in all rats, and no significant differences in the number of F-JB cells in the CA1 area and the hilus was observed between experimental groups. CONCLUSION: Our results indicate that, although GH has an anticonvulsive effect in the lithium-pilocarpine model of SE, it does not exert hippocampal neuroprotection after SE.

Effect of recombinant bovine somatotropin on the reproductive efficiency of beef cows subjected to differently timed-artificial insemination protocols.

This study aimed to verify the reproductive efficiency of beef cows treated with recombinant bovine somatotropin (rbST). Study 1, Bos indicus cows were distributed (three groups). The control group (CG) was subjected: on day zero (d0), the animals received a CIDR and oestradiol benzoate (EB); on (d8, CIDR was removed, and PGF2α and oestradiol cypionate (EC) were administered; on d10, timed Artificial Insemination (TAI) was performed; on d45, pregnancy diagnosis was made. The rbST on d0 group (bST0G) was subjected to an identical protocol as CG, except for the addition of 250 mg rbST on d0. The rbST on d8 group (bST8G) was subjected to the same protocol as bST0G, except that the rbST was administered on d8 rather. In study 2, the animals followed the same design which was used in Bos taurus cows. The follicular growth rate (FGR) was calculated between d8 and d10. In study 1, pregnancy/artificial insemination (P/AI) did not differ among the treatments. FGR in bST8G was higher than in other groups. In study 2, bST0G showed higher Pregnancy/Artificial Insemination (P/AI) (p < .05) when compared with other groups. bST0G showed a different FGR (p < .0001) than the other groups. In conclusion, rbST (Bos indicus cows) did not increase P/AI, but it did promote follicular growth when administered on d8; the rbST administered on d0 improved P/AI (p < .05) and the FGR in Bos taurus cows.

Growth hormone supplementation during ovarian stimulation in women with advanced maternal age undergoing preimplantation genetic testing for Aneuploidy.

BACKGROUND: Studies have shown that supplementation with recombinant human GH (rh-GH) during ovarian stimulation (OS) may improve the ovarian response and clinical outcomes of IVF. However, it remains unclear whether GH is associated with the ploidy status of embryos, and therefore, is unable to explain the underlying reason for the effect of GH on IVF outcomes. This study aimed to investigate whether GH supplementation in women with advanced maternal age (AMA) during OS is related to an increased probability of obtaining euploid blastocysts. METHODS: This was a single center retrospective cohort study. The data of all women aged 38-46 years who underwent their first preimplantation genetic testing for aneuploidy (PGT-A) cycle between January 2021 and June 2022 were reviewed. Patients in the GH group received 4 IU/day subcutaneous GH supplementation from the beginning of OS to the trigger day, and patients in the control group did not. A total of 140 patients in the GH group and 272 patients in the control group were included after 1:2 propensity score matching. RESULTS: The baseline and cycle characteristics between the two groups were similar. The proportion of cycles which obtained euploid blastocysts was significantly higher in the GH group than that in the control group (41.43% vs. 27.21%, P = 0.00). The GH group had a significantly higher euploid blastocyst rate per cohort (32.47% vs. 21.34%, P = 0.00) and mean euploid blastocyst rate per cycle (per biopsy cycle 0.35 ± 0.40 vs. 0.21 ± 0.33, P = 0.00; per OS cycle 0.27 ± 0.38 vs. 0.16 ± 0.30, P = 0.02). However, the benefit of GH was more significant in patients aged 38-40 years, but not significant in patients aged 41-46 years. Pregnancy outcomes were similar between the two groups after embryo transfer. CONCLUSIONS: GH supplementation during OS is associated with a significantly increased probability of obtaining euploid blastocysts in women aged 38-40 years, but this benefit is not significant in women aged 41-46 years. Our results explained the underlying reason for the effect of GH on IVF outcomes in existing studies, and might be helpful for AMA patients undergoing PGT-A cycles to obtain a better outcome meanwhile to avoid over-treatment. TRIAL REGISTRATION: NCT05574894, www. CLINICALTRIALS: gov .

Exercise for optimizing bone health after hormone-induced increases in bone stiffness.

Hormones and mechanical loading co-regulate bone throughout the lifespan. In this review, we posit that times of increased hormonal influence on bone provide opportunities for exercise to optimize bone strength and prevent fragility. Examples include endogenous secretion of growth hormones and sex steroids that modulate adolescent growth and exogenous administration of osteoanabolic drugs like teriparatide, which increase bone stiffness, or its resistance to external forces. We review evidence that after bone stiffness is increased due to hormonal stimuli, mechanoadaptive processes follow. Specifically, exercise provides the mechanical stimulus necessary to offset adaptive bone resorption or promote adaptive bone formation. The collective effects of both decreased bone resorption and increased bone formation optimize bone strength during youth and preserve it later in life. These theoretical constructs provide physiologic foundations for promoting exercise throughout life.

Correspondence on "Sex steroid priming for growth hormone stimulation testing in children and adolescents with short stature: A systematic review".

Duncan et al. reviewed the response to growth hormone stimulation testing after priming in peripubertal children. The concern is that there is little research documenting the response to growth hormone treatment in patients with sex hormone primed growth hormone stimulation testing and those unprimed. The controversy about priming or not can be summarized as follows: if one wants to know if the production of growth hormone during puberty will be adequate in terms of peak growth hormone responses then stimulation with priming should be done.

Effectiveness of growth hormone in promoting endometrial growth in patients with endometrial dysplasia in frozen embryo transfer.

This study was designed to investigate the effect of growth hormone (GH) in promoting endometrial thickness, blood flow, and pregnancy outcome in patients with thin endometrium for frozen embryo transfer. Thirty-eight patients were recruited in the reproductive center of Jingzhou Hospital affiliated to Yangtze University who cancelled fresh embryo transfer due to thin endometrium and planned to undergo frozen-thawed embryo transfer (FET) from May 2019 to May 2020. The patients were randomly divided into the GH injection group (19 cases, endometrium preparation with hormone replacement therapy (HRT) and GH by subcutaneous injection) and the control group (19 cases, endometrium preparation with HRT). Both groups were similar in socio-demographic characteristics. After treatment, the thickness and volume of endometrium in the HRT & GH group were significantly increased (p < 0.05), and the growth rate was significantly higher than that in the control group (p < 0.05). The proportion of type A & B endometrium increased from 78.9% to 94.7% in the HRT & GH group. Moreover, the proportion of type Ⅰ and Ⅱ of endometrial blood perfusion in the HRT & GH group significantly increased compared with that before treatment. The human chorionic gonadotropin (hCG) positive rate (47.4 vs. 42.1%) and clinical pregnancy rate (36.8% vs. 31.6%) were slightly higher in the HRT&GH group than that in the control group. In conclusion, for patients with thin endometrium, HRT combined with subcutaneous injection of GH can increase the thickness and volume of the endometrium, improving the blood perfusion of the endometrium. This may play a positive role in improving endometrial receptivity and pregnancy outcome.

Hyperhomocysteinemia potentiates megakaryocyte differentiation and thrombopoiesis via GH-PI3K-Akt axis.

Hyperhomocysteinemia (HHcy) is closely associated with thrombotic diseases such as myocardial infarction and stroke. Enhanced platelet activation was observed in animals and humans with HHcy. However, the influence of HHcy on thrombopoiesis remains largely unknown. Here, we reported increased platelet count (PLT) in mice and zebrafish with HHcy. In hypertensive patients (n = 11,189), higher serum level of total Hcy was observed in participants with PLT ≥ 291 × 109/L (full adjusted ß, 0.59; 95% CI 0.14, 1.04). We used single-cell RNA sequencing (scRNA-seq) to characterize the impact of Hcy on transcriptome, cellular heterogeneity, and developmental trajectories of megakaryopoiesis from human umbilical cord blood (hUCB) CD34+ cells. Together with in vitro and in vivo analysis, we demonstrated that Hcy promoted megakaryocytes (MKs) differentiation via growth hormone (GH)-PI3K-Akt axis. Moreover, the effect of Hcy on thrombopoiesis is independent of thrombopoietin (TPO) because administration of Hcy also led to a significant increase of PLT in homozygous TPO receptor (Mpl) mutant mice and zebrafish. Administration of melatonin effectively reversed Hcy-induced thrombopoiesis in mice. ScRNA-seq showed that melatonin abolished Hcy-facilitated MK differentiation and maturation, inhibited the activation of GH-PI3K-Akt signaling. Our work reveals a previously unrecognized role of HHcy in thrombopoiesis and provides new insight into the mechanisms by which HHcy confers an increased thrombotic risk.Trial Registration clinicaltrials.gov Identifier: NCT00794885.

Growth hormone treatment improves the development of follicles and oocytes in prepubertal lambs.

BACKGROUND: When prepubertal lambs are superovulated, the ovarian response to gonadotropin stimulation has great individual difference and the collected oocytes have lower developmental ability than that of adult ewes. Over the years, growth hormone (GH) has been used in assisted reproduction because it can improve the reproductive performance in humans and animals. However, the effect of GH on ovaries and oocytes of prepubertal lambs remains unclear. METHODS: Before and during follicle-stimulating hormone (FSH) superovulation of prepubertal lambs (4‒6-week-old), the lambs were treated with high (50 mg) or low dose (25 mg) of ovine GH in a long (5 days) or short (2 days) period. The recovered oocytes were used for in vitro maturation and fertilization, and several parameters of oocyte quality and development capacity were evaluated. The possible underlying mechanisms of GH action were explored by analysis of granulosa cell (GC) transcriptome, ovarian proteome and follicular fluid metabolome. RESULTS: Treatment of lambs with 50 mg GH over 5 days (long treatment) potentially promoted the response of lambs to superovulation and improved the development capacity of retrieved oocytes, consequently increasing the high quality embryo yield from lambs. A number of differently expressed genes or proteins were found in ovaries between GH-treated and untreated lambs. Cellular experiments revealed that GH reduced the oxidative stress of GCs and promoted the GC proliferation probably through activation of the PI3K/Akt signaling pathway. Finally, analysis of follicular fluid metabolome indicated that GH treatment altered the abundance of many metabolites in follicular fluid, such as antioxidants and fatty acids. CONCLUSIONS: GH treatment has a beneficial role on function of lamb ovaries, which supports the development of follicles and oocytes and improves the efficiency of embryo production from prepubertal lambs.

Growth hormone remodels the 3D-structure of the mitochondria of inflammatory macrophages and promotes metabolic reprogramming.

Introduction: Macrophages are a heterogeneous population of innate immune cells that support tissue homeostasis through their involvement in tissue development and repair, and pathogen defense. Emerging data reveal that metabolism may control macrophage polarization and function and, conversely, phenotypic polarization may drive metabolic reprogramming. Methods: Here we use biochemical analysis, correlative cryogenic fluorescence microscopy and cryo-focused ion-beam scanning electron microscopy. Results: We demonstrate that growth hormone (GH) reprograms inflammatory GM-CSF-primed monocyte-derived macrophages (GM-MØ) by functioning as a metabolic modulator. We found that exogenous treatment of GM-MØ with recombinant human GH reduced glycolysis and lactate production to levels similar to those found in anti-inflammatory M-MØ. Moreover, GH treatment of GM-MØ augmented mitochondrial volume and altered mitochondrial dynamics, including the remodeling of the inner membrane to increase the density of cristae. Conclusions: Our data demonstrate that GH likely serves a modulatory role in the metabolism of inflammatory macrophages and suggest that metabolic reprogramming of macrophages should be considered as a new target to intervene in inflammatory diseases.

Growth hormone reduces aneuploidy and improves oocytes quality by JAK2-MAPK3/1 pathway in aged mice.

BACKGROUND: The global delay in women's reproductive age has raised concerns about age-related infertility. The decline in oocyte quality is a limiting factor of female fertility, yet there are currently no strategies to preserve oocyte quality in aged women. Here, we investigated the effects of growth hormone (GH) supplementation on aneuploidy of aged oocytes. METHODS: For the in vivo experiments, the aged mice (8-month-old) were intraperitoneally injected with GH daily for 8 weeks. For the in vitro experiments, germinal vesicle oocytes from aged mice were treated with GH during oocyte maturation. The impacts of GH on ovarian reserve before superovulation was evaluated. Oocytes were retrieved to assess oocyte quality, aneuploidy and developmental potential characteristics. Quantitative proteomics analysis was applied to investigate the potential targets of GH in aged oocytes. RESULTS: In this study, we demonstrated that GH supplementation in vivo not only alleviated the decline in oocyte number caused by aging, but also improved the quality and developmental potential of aged oocytes. Strikingly, we discovered that GH supplementation reduced aneuploidy in aged oocytes. Mechanically, in addition to improving mitochondrial function, our proteomic analysis indicated that the MAPK3/1 pathway may be involved in the reduction in aneuploidy of aged oocytes, as confirmed both in vivo and in vitro. In addition, JAK2 may also act as a mediator in how GH regulates MAPK3/1. CONCLUSIONS: In conclusion, our research reveals that GH supplementation protects oocytes against aging-related aneuploidy and enhances the quality of aged oocytes, which has clinical significance for aged women undergoing assisted reproduction technology.

Growth hormone secretagogues modulate inflammation and fibrosis in mdx mouse model of Duchenne muscular dystrophy.

Introduction: Growth hormone secretagogues (GHSs) exert multiple actions, being able to activate GHS-receptor 1a, control inflammation and metabolism, to enhance GH/insulin-like growth factor-1 (IGF-1)-mediated myogenesis, and to inhibit angiotensin-converting enzyme. These mechanisms are of interest for potentially targeting multiple steps of pathogenic cascade in Duchenne muscular dystrophy (DMD). Methods: Here, we aimed to provide preclinical evidence for potential benefits of GHSs in DMD, via a multidisciplinary in vivo and ex vivo comparison in mdx mice, of two ad hoc synthesized compounds (EP80317 and JMV2894), with a wide but different profile. 4-week-old mdx mice were treated for 8 weeks with EP80317 or JMV2894 (320 µg/kg/d, s.c.). Results: In vivo, both GHSs increased mice forelimb force (recovery score, RS towards WT: 20% for EP80317 and 32% for JMV2894 at week 8). In parallel, GHSs also reduced diaphragm (DIA) and gastrocnemius (GC) ultrasound echodensity, a fibrosis-related parameter (RS: ranging between 26% and 75%). Ex vivo, both drugs ameliorated DIA isometric force and calcium-related indices (e.g., RS: 40% for tetanic force). Histological analysis highlighted a relevant reduction of fibrosis in GC and DIA muscles of treated mice, paralleled by a decrease in gene expression of TGF-ß1 and Col1a1. Also, decreased levels of pro-inflammatory genes (IL-6, CD68), accompanied by an increment in Sirt-1, PGC-1α and MEF2c expression, were observed in response to treatments, suggesting an overall improvement of myofiber metabolism. No detectable transcript levels of GHS receptor-1a, nor an increase of circulating IGF-1 were found, suggesting the presence of a novel receptor-independent mechanism in skeletal muscle. Preliminary docking studies revealed a potential binding capability of JMV2894 on metalloproteases involved in extracellular matrix remodeling and cytokine production, such as ADAMTS-5 and MMP-9, overactivated in DMD. Discussion: Our results support the interest of GHSs as modulators of pathology progression in mdx mice, disclosing a direct anti-fibrotic action that may prove beneficial to contrast pathological remodeling.

Central growth hormone action regulates neuroglial and proinflammatory markers in the hypothalamus of male mice.

Growth hormone (GH) action in specific neuronal populations regulates neuroendocrine responses, metabolism, and behavior. However, the potential role of central GH action on glial function is less understood. The present study aims to determine how the hypothalamic expression of several neuroglial markers is affected by central GH action in male mice. The dwarf GH- and insulin-like growth factor-1 (IGF-1)-deficient Ghrhrlit/lit mice showed decreased mRNA expression of Nes (Nestin), Gfap, Iba1, Adgre1 (F4/80), and Tnf (TNFα) in the hypothalamus, compared to wild-type animals. In contrast, transgenic overexpression of GH led to high serum GH and IGF-1 levels, and increased hypothalamic expression of Nes, Gfap, Adgre1, Iba1, and Rax. Hepatocyte-specific GH receptor (GHR) knockout mice, which are characterized by high serum GH levels, but reduced IGF-1 secretion, showed increased mRNA expression of Gfap, Iba1, Tnf, and Sox10, demonstrating that the increase in GH levels alters the hypothalamic expression of glial markers associated with neuroinflammation, independently of IGF-1. Conversely, brain-specific GHR knockout mice showed reduced expression of Gfap, Adgre1, and Vim (vimentin), indicating that brain GHR signaling is necessary to mediate GH-induced changes in the expression of several neuroglial markers. In conclusion, the hypothalamic mRNA levels of several neuroglial markers associated with inflammation are directly modulated by GHR signaling in male mice.

Growth hormone-releasing hormone antagonists protect against hydrochloric acid-induced endothelial injury in vitro.

Growth hormone-releasing hormone (GHRH) regulates the synthesis of growth hormone from the anterior pituitary gland, and it is involved in inflammatory responses. On the other hand, GHRH antagonists (GHRHAnt) exhibit the opposite effects, resulting in endothelial barrier enhancement. Exposure to hydrochloric acid (HCL) is associated with acute and chronic lung injury. In this study, we investigate the effects of GHRHAnt in HCL-induced endothelial barrier dysfunction, utilizing commercially available bovine pulmonary artery endothelial cells (BPAEC). Cell viability was measured by utilizing 3-(4,5-dimethylthiazol2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay. Moreover, fluorescein isothiocyanate (FITC)-dextran was used to assess barrier function. Our observations suggest that GHRHAnt exert protective effects against HCL-induced endothelial breakdown, since those peptides counteract HCL-triggered paracellular hyperpermeability. Based on those findings, we propose that GHRHAnt represent a new therapeutic approach towards HCL-induced endothelial injury.

Inflammation induces stunting by lowering bone mass via GH/IGF-1 inhibition in very preterm infants.

BACKGROUND: Sustained systemic inflammatory response (SIR) was associated with poor postnatal growth in very preterm infants (VPI). We hypothesize that VPI with sustained SIR will exhibit linear growth retardation related to lower bone mass accrual mediated by GH/IGF-1 axis inhibition at term corrected age (CA). METHODS: C-reactive protein (CRP), procalcitonin (PCT), growth hormone (GH), insulin-like growth factor 1 (IGF-1), calcium, phosphorus, alkaline phosphatase, anthropometric, nutritional, neonatal and maternal data were collected prospectively in 23 infants <32 weeks gestational age. Body composition using dual-energy X-ray absorptiometry was performed at term CA. Analysis was undertaken with multiple linear regression models. RESULTS: At term CA 11 infants with sustained SIR compared with 12 infants without sustained SIR present significantly lower IGF-1, length z-score (LZS), bone mineral content (BMC) and lean mass (LM), and higher GH and fat mass (FM). LZS was associated significantly with PCT, BMC with IGF-1, FM and LM with CRP, GH with bronchopulmonary dysplasia and CRP, and IGF-1 with invasive mechanical ventilation, CRP and PCT. CONCLUSIONS: In addition to the known effect on linear growth failure, sustained SIR induces lower bone mass accrual related to higher GH and lower IGF-1 levels in VPI. IMPACT: Very preterm infants (VPI) with sustained systemic inflammatory response (SIR) compared with VPI without SIR present stunting, lower bone mass, higher GH and lower IGF-1 levels at term corrected age. SIR may help to explain the influence of non-nutritional factors on growth and body composition in VPI. SIR induces postnatal stunting related to lower bone mass accrual via GH/IGF-1 axis inhibition in VPI. VPI with SIR need special attention to minimize inflammatory stress, which could result in improved postnatal growth. Research on inflammatory-endocrine interactions involved in the pathophysiology of postnatal stunting is needed as a basis for new interventional approaches.