Expression, regulation and biological actions of growth hormone (GH) and ghrelin in the immune system

CD4+ T-Cell Senescence in Neurodegenerative Disease: Pathogenesis and Potential Therapeutic Targets

With the increasing proportion of the aging population, neurodegenerative diseases have become one of the major health issues in society. Neurodegenerative diseases (NDs), including multiple sclerosis (MS), Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS), are characterized by progressive neurodegeneration associated with aging, leading to a gradual decline in cognitive, emotional, and motor functions in patients. The process of aging is a normal physiological process in human life and is accompanied by the aging of the immune system, which is known as immunosenescence. T-cells are an important part of the immune system, and their senescence is the main feature of immunosenescence. The appearance of senescent T-cells has been shown to potentially lead to chronic inflammation and tissue damage, with some studies indicating a direct link between T-cell senescence, inflammation, and neuronal damage. The role of these subsets with different functions in NDs is still under debate. A growing body of evidence suggests that in people with a ND, there is a prevalence of CD4+ T-cell subsets exhibiting characteristics that are linked to senescence. This underscores the significance of CD4+ T-cells in NDs. In this review, we summarize the classification and function of CD4+ T-cell subpopulations, the characteristics of CD4+ T-cell senescence, the potential roles of these cells in animal models and human studies of NDs, and therapeutic strategies targeting CD4+ T-cell senescence.

Sports and Immunity, from the recreational to the elite athlete

The pivotal role of the immune system in physical activity is well-established. While interactions are complex, they tend to constitute discrete immune responses. Moderate intensity exercise causes leukocytosis with a mild anti-inflammatory cytokine profile and immunoenhancement. Above a threshold of intensity, lactate-mediated IL-6 release causes a proinflammatory state followed by a depressed inflammatory state, which stimulates immune adaptation and longer term cardiometabolic enhancement. Exercise-related immune responses are modulated by sex, age and immunonutrition. At all ability levels, these factors collectively affect the immune balance between enhancement or overload and dysfunction. Excessive training, mental stress or insufficient recovery risks immune cell exhaustion and hypothalamic pituitary axis (HPA) stress responses causing immunodepression with negative impacts on performance or general health. Participation in sport provides additional immune benefits in terms of ensuring regularity, social inclusion, mental well-being and healthier life choices in terms of diet and reduced smoking and alcohol, thereby consolidating healthy lifestyles and longer term health. Significant differences exist between recreational and professional athletes in terms of inherent characteristics, training resilience and additional stresses arising from competition schedules, travel-related infections and stress. Exercise immunology examines the central role of immunity in exercise physiology and straddles multiple disciplines ranging from neuroendocrinology to nutrition and genetics, with the aim of guiding athletes to train optimally and safely. This review provides a brief outline of the main interactions of immunity and exercise, some influencing factors, and current guidance on maintaining immune health.

Biochemical Examination of Plasma Ghrelin Levels in Individuals Afflicted With Chronic Periodontal Disease: A Comparative Study

OBJECTIVE

This study intended to assess plasma ghrelin levels in individuals with chronic periodontitis and analyze potential associations with bone turnover indicators, serum cytokines, and periodontal parameters.

MATERIAL AND METHODS

The research contained 80 patients each with 40 individuals with periodontally healthy controls (C) (28 males, 12 females) and 40 chronic periodontitis (CP) patients (29 males, 11 females). The blood samples were analyzed for soluble receptor activator nuclear factor kappa B ligand (sRANKL), interleukin-1 beta (IL-1β), total and acylated ghrelin, tumor necrosis factor-alpha (TNF-α), osteocalcin (OSC) and alkaline phosphatase (ALP), and periodontal parameters were recorded.

RESULTS

The CP group had considerably higher plasma concentrations of both acylated and total ghrelin than the C group (p<0.05). Gender-based investigation showed substantial differences only among men in both groups (p<0.05). Hence, no significant modifications were identified in serum sRANKL, TNFα, and ALP levels between the groups. However, there was a notable difference in serum OSC and IL-1β levels in the CP group (p<0.05). Furthermore, total ghrelin/acylated ghrelin and total ghrelin/ALP revealed positive correlations. No significant association was found between symptoms and ghrelin levels.

CONCLUSION

The study findings indicate elevated levels of ghrelin and acylated ghrelin in male CP patients.

Insulin-like growth factor-1 expression levels in pro-inflammatory response in calves with neonatal systemic inflammatory response syndrome

The objective of this study was to investigate the mRNA expression of insulin-like growth factor-1 (IGF-1), pro-inflammatory cytokines (IL-1β, IL-6, IL-18, and TNF-α), serum immunoglobulin profiles (IgG and IgM), and lipid peroxidation status (MDA) in relation to pro-inflammatory cytokines. A case-controlled, prospective, and observational investigation was completed on 85 calves. Total RNA was isolated from whole blood samples of both the SIRS and healthy calves, followed by reverse transcription into cDNA. The resulting cDNAs were mixed with iTaq Universal SYBR Green Supermix and primers specific to the relevant genes using the Rotor-Gene Q instrument. After the reaction was completed, gene expressions were normalised against β-actin using the 2-ΔΔCT method. The mRNA levels of pro-inflammatory cytokines namely (IL-1β [SIRS: 2.15 ± 0.55, Control: 1.13 ± 0.62; P = 0.001], IL-6 [SIRS: 2.82 ± 0.52, Control: 0.91 ± 0.11; P < 0.001], IL-18 [SIRS: 1.92 ± 0.41, Control: 0.99 ± 0.13; P < 0.001], and TNF-α [SIRS: 2.59 ± 0.28, Control: 0.93 ± 0.09; P < 0.001]) and IGF-1 (SIRS: 3.55 ± 0.55, Control: 0.91 ± 0.15; P < 0.001) were up-regulated in calves with SIRS, while serum IgG (SIRS: 4.16 ± 0.26, Control: 1.73 ± 0.17; P < 0.001), IgM (SIRS: 1.55 ± 0.11, Control: 1.09 ± 0.13; P < 0.001), and MDA levels (SIRS: 41.12 ± 3.48, Control: 3.76 ± 0.81; P < 0.001) increased significantly in these calves. Furthermore, significant (P < 0.01) positive correlations were found in calves with SIRS in relation to the expression levels of IL-1β, IL-6, IL-18, TNF-α, IGF-1, serum immunoglobulins, and MDA levels. These results suggest that IGF-1 could be a valuable pro-inflammatory marker, considering its high positive correlation with the expression levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-18, and TNF-α) and markers (MDA, IgG, and IgM) in calves with SIRS.

Changes in Circulating Acylated Ghrelin and Neutrophil Elastase in Diabetic Retinopathy

Background and Objectives: The role and the levels of ghrelin in diabetes-induced retinal damage have not yet been explored. The present study aimed to measure the serum levels of total ghrelin (TG), and its acylated (AG) and des-acylated (DAG) forms in patients with the two stages of diabetic retinopathy (DR), non-proliferative (NPDR) and proliferative (PDR). Moreover, the correlation between serum ghrelin and neutrophil elastase (NE) levels was investigated. Materials and Methods: The serum markers were determined via enzyme-linked immunosorbent assays in 12 non-diabetic subjects (CTRL), 15 diabetic patients without DR (Diabetic), 15 patients with NPDR, and 15 patients with PDR. Results: TG and AG serum levels were significantly decreased in Diabetic (respectively, p < 0.05 and p < 0.01 vs. CTRL), NPDR (p < 0.01 vs. Diabetic), and in PDR patients (p < 0.01 vs. NPDR). AG serum levels were inversely associated with DR abnormalities (microhemorrhages, microaneurysms, and exudates) progression (r = -0.83, p < 0.01), serum neutrophil percentage (r = -0.74, p < 0.01), and serum NE levels (r = -0.73, p < 0.01). The latter were significantly increased in the Diabetic (p < 0.05 vs. CTRL), NPDR (p < 0.01 vs. Diabetic), and PDR (p < 0.01 vs. PDR) groups. Conclusions: The two DR stages were characterized by decreased AG and increased NE levels. In particular, serum AG levels were lower in PDR compared to NPDR patients, and serum NE levels were higher in the PDR vs. the NPDR group. Together with the greater presence of retinal abnormalities, this could underline a distinctive role of AG in PDR compared to NPDR.

Is there a role for growth hormone replacement in adults to control acute and post-acute COVID-19?

The SARS-CoV-2 pandemic created a multitude of medical crossroads requiring real time adaptations of best practice covering preventative and interventional aspects of care. Among the many discoveries borne from efforts to address the myriad clinical presentations across multiple organ systems was a common impact on tissues with cells that express the ACE-2 receptor. The vast majority of acute infections began and often ended in the respiratory tract, but more recent evaluations have confirmed significant extrapulmonary manifestations including symptom clusters that extend beyond the acute phase of infection collectively referred to as "post-acute sequelae SARS-CoV-2 infection" (PASC) or more commonly as "long (-haul) COVID". Both acute SARS-CoV-2 infection and PASC are associated with gut microbiome dysbiosis and alterations in the gut-brain and HPA-axis in a subset of the infected. Mounting evidence suggests these extrapulmonary manifestations may ultimately lead to reduced growth hormone (GH) secretion as demonstrated following stimulation tests. Disrupted GH secretion could cause or exacerbate long lasting neuropsychological symptoms as seen in other similar manifesting conditions. Ongoing clinical research has shown promising improvement in PASC patients with fatigue and cognition complaints can be achieved via GH replacement therapy. GH stimulation testing should be considered in PASC workups and future research should delve deeper into the mechanistic effects of GH on acute COVID and PASC.

Obesity-induced thymic involution and cancer risk

Declining thymic functions associated either with old age (i.e., age-related thymic involution), or with acute involution as a result of stress, infectious disease, or cytoreductive therapies (e.g., chemotherapy/radiotherapy), have been associated with cancer development. A key mechanism underlying such increased cancer risk is the thymus-dependent debilitation of adaptive immunity, which is responsible for orchestrating immunoediting mechanisms and tumor immune surveillance. In the past few years, a blooming set of evidence has intriguingly linked obesity with cancer development and progression. The majority of such studies has focused on obesity-driven chronic inflammation, steroid/sex hormone and adipokine production, and hyperinsulinemia, as principal factors affecting the tumor microenvironment and driving the development of primary malignancy. However, experimental observations about the negative impact of obesity on T cell development and maturation have existed for more than half a century. Here, we critically discuss the molecular and cellular mechanisms of obesity-driven thymic involution as a previously underrepresented intermediary pathology leading to cancer development and progression. This knowledge could be especially relevant in the context of childhood obesity, because impaired thymic function in young individuals leads to immune system abnormalities, and predisposes to various pediatric cancers. A thorough understanding behind the molecular and cellular circuitries governing obesity-induced thymic involution could therefore help towards the rationalized development of targeted thymic regeneration strategies for obese individuals at high risk of cancer development.

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.

Effects of GHR Deficiency and Juvenile Hypoglycemia on Immune Cells of a Porcine Model for Laron Syndrome

Laron syndrome (LS) is a rare genetic disorder characterized by low levels of insulin-like growth factor 1 (IGF1) and high levels of growth hormone (GH) due to mutations in the growth hormone receptor gene (GHR). A GHR-knockout (GHR-KO) pig was developed as a model for LS, which displays many of the same features as humans with LS-like transient juvenile hypoglycemia. This study aimed to investigate the effects of impaired GHR signaling on immune functions and immunometabolism in GHR-KO pigs. GHR are located on various cell types of the immune system. Therefore, we investigated lymphocyte subsets, proliferative and respiratory capacity of peripheral blood mononuclear cells (PBMCs), proteome profiles of CD4− and CD4+ lymphocytes and IFN-α serum levels between wild-type (WT) controls and GHR-KO pigs, which revealed significant differences in the relative proportion of the CD4+CD8α− subpopulation and in IFN-α levels. We detected no significant difference in the respiratory capacity and the capacity for polyclonal stimulation in PBMCs between the two groups. But proteome analysis of CD4+ and CD4− lymphocyte populations revealed multiple significant protein abundance differences between GHR-KO and WT pigs, involving pathways related to amino acid metabolism, beta-oxidation of fatty acids, insulin secretion signaling, and oxidative phosphorylation. This study highlights the potential use of GHR-KO pigs as a model for studying the effects of impaired GHR signaling on immune functions.

The potential role of the thymus in immunotherapies for acute myeloid leukemia

Understanding the factors which shape T-lymphocyte immunity is critical for the development and application of future immunotherapeutic strategies in treating hematological malignancies. The thymus, a specialized central lymphoid organ, plays important roles in generating a diverse T lymphocyte repertoire during the infantile and juvenile stages of humans. However, age-associated thymic involution and diseases or treatment associated injury result in a decline in its continuous role in the maintenance of T cell-mediated anti-tumor/virus immunity. Acute myeloid leukemia (AML) is an aggressive hematologic malignancy that mainly affects older adults, and the disease's progression is known to consist of an impaired immune surveillance including a reduction in naïve T cell output, a restriction in T cell receptor repertoire, and an increase in frequencies of regulatory T cells. As one of the most successful immunotherapies thus far developed for malignancy, T-cell-based adoptive cell therapies could be essential for the development of a durable effective treatment to eliminate residue leukemic cells (blasts) and prevent AML relapse. Thus, a detailed cellular and molecular landscape of how the adult thymus functions within the context of the AML microenvironment will provide new insights into both the immune-related pathogenesis and the regeneration of a functional immune system against leukemia in AML patients. Herein, we review the available evidence supporting the potential correlation between thymic dysfunction and T-lymphocyte impairment with the ontogeny of AML (II-VI). We then discuss how the thymus could impact current and future therapeutic approaches in AML (VII). Finally, we review various strategies to rejuvenate thymic function to improve the precision and efficacy of cancer immunotherapy (VIII).

Human growth hormone supplement promotes human lymphohematopoietic cell reconstitution in immunodeficient mice

Aim: To investigate the potential of human growth hormone (hGH) to improve human hematopoietic reconstitution in humanized mice. Materials & methods: Immunodeficient mice were conditioned by total body irradiation and transplanted with human CD34⁺ fetal liver cells. Peripheral blood, spleen and bone marrow were harvested, and levels of human lymphohematopoietic cells were determined by flow cytometry. Results: Supplementation with hGH elevated human lymphohematopoietic chimerism by more than twofold. Treatment with hGH resulted in significantly increased reconstitution of human B cells and myeloid cells in lymphoid organs, enhanced human erythropoiesis in the bone morrow, and improved engraftment of human hematopoietic stem cells. Conclusion: hGH supplementation promotes human lymphohematopoietic reconstitution in humanized mice.

The Modulatory Role of Growth Hormone in Inflammation and Macrophage Activation

Inflammation is a body's response to remove harmful stimuli and heal tissue damage, which is involved in various physiology and pathophysiology conditions. If dysregulated, inflammation may lead to significant negative impacts. Growth hormone (GH) has been shown responsible for not only body growth but also critical in the modulation of inflammation. In this review, we summarize the current clinical and animal studies about the complex and critical role of GH in inflammation. Briefly, GH excess or deficiency may lead to pathological inflammatory status. In inflammatory diseases, GH may serve as an inflammatory modulator to control the disease progression and promote disease resolution. The detailed mechanisms and signaling pathways of GH on inflammation, with a focus on the modulation of macrophage polarization, are carefully discussed with potential direction for future investigations.

Gut peptide changes in patients with obstructive jaundice undergoing biliary drainage: A prospective case control study

BACKGROUND

Biliary obstruction is a relatively common condition that affects approximately 5 in 1000 people annually. Malnutrition is very common in patients with biliary obstruction and since it is associated with significant morbidity and mortality, it is important to identify factors and mechanisms involved in its development.

AIM

To determine the influence of obstructive jaundice on the hormones controlling appetite and nutritive status.

METHODS

This was a prospective case control study performed in a tertiary center in Zagreb, Croatia. Patients with biliary obstruction undergoing internal biliary drainage from September 2012 until August 2013 were enrolled. After excluding patients who developed procedure related complications or were lost in the follow-up, out of initial 73 patients, 55 patients were included in the analysis, including 34 with benign and 21 with malignant disease. Meanwhile, 40 non-jaundiced controls were also included. Appetite, nutritional status, and serum ghrelin, cholecystokinin (CCK), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α) were determined at admission, 48 h and 28 d after internal biliary drainage. Chi square test was used for categorical variables. Continuous variables were analysed for normality by Kolmogorov–Smirnov test and relevant non-parametric (Mann-Whitney, Kruskal-Wallis, and Friedman) or parametric (t-test and analysis of variance) tests were used.

RESULTS

Patients with obstructive jaundice were significantly malnourished compared to controls, regardless of disease etiology. Plasma ghrelin and CCK levels were significantly higher in patients with obstructive jaundice. Serum bilirubin concentrations were negatively correlated with ghrelin levels and positively correlated with TNF-α, but had no correlation with CCK concentrations. After internal biliary drainage, a significant improvement of nutritional status was observed although serum concentrations of ghrelin, IL-6, and TNF-α remained significantly elevated even 28 d after the procedure. CCK levels in patients without malnutrition remained elevated 28 d after the procedure, but in patients with malnutrition, CCK levels decreased to levels comparable with those in the control group. We have not established any correlation between appetite and serum levels of ghrelin, CCK, IL-6, and TNF-α before and after biliary drainage.

CONCLUSION

Possible abnormalities in ghrelin and CCK regulation may be associated with the development of malnutrition during the inflammatory response in patients with biliary obstruction.

Growth hormone secretagogue receptor deficiency promotes lung cancer growth by affecting the Th17/Treg balance

Background

Cluster of differentiation 4 (CD4⁺) T cells plays a prominent role in eliminating cancer cells. The balance between T helper (Th)17 and regulatory T (Treg) cells is crucial for optimal immune response and protection against cancer. Growth hormone secretagogue receptor 1a (GHSR1a), a member of the G protein-coupled protein receptor superfamily, plays a critical role in immune cell function. The aim of our study is to investigate the role of GHSR1a in CD4⁺ T cell differentiation and lung cancer progression.

Methods

A subcutaneous lung cancer model was used to examine the role of GHSR1a in controlling tumor growth. Lewis lung carcinoma (LLC) cells were subcutaneously implanted into Ghsr1a^−/− mice and wild-type (WT) mice. The ratio of Th17 and Treg in the draining lymph node of Ghsr1a^−/− mice and WT tumor-bearing mice was detected by fluorescence-activated cell sorting (FACS). The effect of GHSR1a deficiency on Th17 and Treg cell differentiation was examined using an in vitro differentiation assay. The phosphorylation of mammalian target of rapamycin (mTOR), signal transducer, and activator of transcription (STAT)3 and STAT5 signaling was detected with Western blot.

Results

We found that the ablation of GHSR1a resulted in impaired anti-tumor immunity to control lung cancer growth in vivo. We also demonstrated that the deficiency of GHSR1a promoted a shift in the Th17/Treg balance toward enhanced Treg differentiation and inhibited Th17 differentiation both in vivo and in vitro, which suggests that GHSR1a regulates T cell lineage choices between Th17 and Treg cell commitment in the tumor microenvironment. Mechanistically, the deficiency of GHSR1a resulted in reduced phosphorylation in mTOR and STAT3, and increased phosphorylation in STAT5.

Conclusions

Our findings showed the important role of GHSR1a in CD4⁺ T cell differentiation in the context of the lung cancer microenvironment. This research provides a novel molecular target and insights into interventions for the prevention and treatment of lung cancer.

Evaluation of stress, serum and salivary ghrelin and cortisol levels in smokers and non-smokers with stage iii periodontitis - A cross-sectional study

BACKGROUND

The present study aimed to investigate the serum and salivary ghrelin and cortisol levels in smokers and non-smokers with Stage III Periodontitis.

METHODS

The present study comprised of a total of 90 systemically healthy patients categorized in three groups: Group I- Periodontally healthy patients; Group II- Non-smokers with Stage III Periodontitis and Group III- Smokers with Stage III periodontitis. Clinical parameters of Probing pocket depth (PPD), Clinical attachment levels (CAL), Plaque Index (PI), Gingival Index (GI) and Papillary Bleeding Index (PBI)were recorded and biochemical parameters of serum and salivary ghrelin and cortisol levels were analyzed via Enzyme Linked Immunosorbent Assay (ELISA). Stress levels were assessed using Zung's self-rating depression scale.

RESULTS

Serum and salivary ghrelin values were found to be higher in Group II (620.25 ± 260.86 pg/ml, 892.40 ± 271.65 pg/ml respectively) as compared to Group III. Similarly, salivary as well as serum cortisol levels were higher in Group III (20.78 ± 9.23 pg/ml, 399.37 ±189.21 pg/ml respectively) as compared to Group II (16.36 ± 8.88 pg/ml, 320.68 ± 107.01 pg/ml respectively). In Group III, a direct correlation was observed between stress, serum and salivary cortisol levels while an inverse correlation was found between stress, serum and salivary ghrelin levels. Group III showed a greater number of depressed patients followed by Group II and I.

CONCLUSION

As per the results smokers with Stage III Periodontitis exhibit an elevated stress and cortisol levels, lower serum and salivary ghrelin levels as compared to the non-smokers. This article is protected by copyright. All rights reserved.

Growth hormone secretagogue peptide-6 enhances oreochromicins transcription and antimicrobial activity in tilapia (Oreochromis sp.)

Growth Hormone-Releasing Peptide 6 (GHRP-6) (His-(D-Trp)-Ala-Trp-(D-Phe)-Lys-NH2) is an agonist of the growth hormone secretagogue receptor. GHRP-6 mimics the effect of ghrelin. The present study focuses on the immunomodulatory effects of GHRP-6 in tilapia with and without the presence of Pseudomonas aeruginosa infection. GHRP-6 up-regulated the transcription levels of three piscidin-like antimicrobial peptides (Oreochromicins I, II, and III) and granzyme in a tissue-dependent manner. Antimicrobial activity stimulation in serum (lysozyme and anti-protease activity) was also confirmed. Besides, GHRP-6 enhanced the in vitro antimicrobial activity against P. aeruginosa in tilapia gills mucus and serum samples and decreased the bacterial load in vivo after infection with this Gram-negative bacterium. Our results evidenced, for the first time, a direct link between a growth hormone secretagogue ghrelin mimetic in fish and the enhancement of antimicrobial peptides transcription, which suggests that this secretagogue is capable to lead the activation of microbicidal activity in tilapia. Thus, these results open new possibilities for GHRP-6 application in aquaculture to stimulate the teleost immune system as an alternative treatment against opportunistic bacteria.

Mutations in GH1 gene and isolated growth hormone deficiency (IGHD): A familial case of IGHD type I and systematic review

BACKGROUND

Isolated growth hormone deficiency (IGHD) due to mutations in GH1 gene is a rare disease caused by deficient production of endogenous growth hormone (GH).

METHODS

We reported the clinical manifestation and genetic diagnosis (whole exome sequencing [WES], nested PCR Sanger sequencing, and rtPCR) of a family with two children with IGHD type I. We conducted a systematic review of cases with IGHD and compared height, and treatment outcomes in subtypes of IGHD.

RESULTS

The patients were siblings born of nonconsanguineous parents from the Chinese Han population. The siblings both presented significantly short stature without other apparent abnormalities. The patients carry compound heterozygous mutations in GH1: a deletion and c.456 + 1G > A mutation that led to abnormal splicing. The systematic review identified 365 IGHD cases with GH1 mutations. Among these patients, their body height was most severely impaired in patients with IGHD type Ia, and the height standard deviation score decreased with the age of diagnosis in IGHD type Ia. Patients with IGHD type II had the longest duration of rhGH treatment, while patients with IGHD type Ib had the highest relative height improvement.

CONCLUSION

We identified two patients with IGHD type I caused by compound heterozygotic GH1 deletion and splicing mutation. The analysis of previously published IGHD patients suggests differences in linear growth among subtypes of IGHD.

The "Adipo-Cerebral" Dialogue in Childhood Obesity: Focus on Growth and Puberty. Physiopathological and Nutritional Aspects

Overweight and obesity in children and adolescents are overwhelming problems in western countries. Adipocytes, far from being only fat deposits, are capable of endocrine functions, and the endocrine activity of adipose tissue, resumable in adipokines production, seems to be a key modulator of central nervous system function, suggesting the existence of an “adipo-cerebral axis.” This connection exerts a key role in children growth and puberty development, and it is exemplified by the leptin–kisspeptin interaction. The aim of this review was to describe recent advances in the knowledge of adipose tissue endocrine functions and their relations with nutrition and growth. The peculiarities of major adipokines are briefly summarized in the first paragraph; leptin and its interaction with kisspeptin are focused on in the second paragraph; the third paragraph deals with the regulation of the GH-IGF axis, with a special focus on the model represented by growth hormone deficiency (GHD); finally, old and new nutritional aspects are described in the last paragraph.

COVID-19: Sleep, Circadian Rhythms and Immunity - Repurposing Drugs and Chronotherapeutics for SARS-CoV-2

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has affected nearly 28 million people in the United States and has caused more than five hundred thousand deaths as of February 21, 2021. As the novel coronavirus continues to take its toll in the United States and all across the globe, particularly among the elderly (>65 years), clinicians and translational researchers are taking a closer look at the nexus of sleep, circadian rhythms and immunity that may contribute toward a more severe coronavirus disease-19 (COVID-19). SARS-CoV-2-induced multi-organ failure affects both central and peripheral organs, causing increased mortality in the elderly. However, whether differences in sleep, circadian rhythms, and immunity between older and younger individuals contribute to the age-related differences in systemic dysregulation of target organs observed in SARS-CoV-2 infection remain largely unknown. Current literature demonstrates the emerging role of sleep, circadian rhythms, and immunity in the development of chronic pulmonary diseases and respiratory infections in human and mouse models. The exact mechanism underlying acute respiratory distress syndrome (ARDS) and other cardiopulmonary complications in elderly patients in combination with associated comorbidities remain unclear. Nevertheless, understanding the critical role of sleep, circadian clock dysfunction in target organs, and immune status of patients with SARS-CoV-2 may provide novel insights into possible therapies. Chronotherapy is an emerging concept that is gaining attention in sleep medicine. Accumulating evidence suggests that nearly half of all physiological functions follow a strict daily rhythm. However, healthcare professionals rarely take implementing timed-administration of drugs into consideration. In this review, we summarize recent findings directly relating to the contributing roles of sleep, circadian rhythms and immune response in modulating infectious disease processes, and integrate chronotherapy in the discussion of the potential drugs that can be repurposed to improve the treatment and management of COVID-19.

Coupling Complete Blood Count and Steroidomics to Track Low Doses Administration of Recombinant Growth Hormone: An Anti-Doping Perspective

Growth Hormone (GH) under its human recombinant homologue (rhGH), may be abused by athletes to take advantage of its well-known anabolic and lipolytic properties; hence it is prohibited in sports by the World Anti-Doping Agency. Due to the rapid turnover of rhGH, anti-doping screening tests have turned to monitor two endocrine biomarkers (IGF-I and P-III-NP), but unfortunately, they show population-wise variability, limiting the identification rate of rhGH users. Previous studies have evidenced the numerous effects of GH on human physiology, especially in hematopoiesis and steroidogenesis. In this work, aiming to discover novel physiological rhGH biomarkers, we analyzed the complete blood count and the steroidomics profile of healthy, physically active, young males treated either with EPO + rhGH or EPO + placebo. The time-trends of these two physiological routes have been analyzed through geometric trajectory analysis (GTA) and OPLS-DA. Individuals supplemented with micro-doses of rhGH exhibited different leukopoietic and steroidal profiles compared to the control population, suggesting a role of the rhGH in both pathways. In the article, hypotheses on the observed differences are discussed according to the most recent literature and compared to results in animal models. The use of leukopoietic and steroidal biomarkers together with endocrine biomarkers (IGF-1 and P-III-NP) allows to correctly classify over 98% of samples with no false positives, miss-classifying only one single sample (false negative) over a total of 56; a promising result, if compared to the current rhGH detection strategies.

Ghrelin Expression in Mast Cells of Infant Lung with Respiratory Distress Syndrome

This article sheds light on some features of ghrelin (GHR)- and tryptase (Try)-positive mast cells (MCs) distribution in human lung of preterm newborns with respiratory distress syndrome (RDS). GHR possessed anti-inflammatory activity and reliable therapeutic properties in some lung diseases. So far, GHR expression has been defined predominantly in neuroendocrine cells of bronchial mucosa in fetal and infant lungs. Lung tissue from 8 dead newborns with RDS were investigated immunohistochemically with anti-GHR and anti-Try antibodies. The number of GHR+ and Try+ MCs was determined in three locations –bronchi, bronchiole and in alveolar septa. MCs were more numerous around main bronchi with diminishing numbers around bronchiole and in alveolar septa. The number of MCs in the latter was increased in newborns with pneumonia. The number of GHR+ MCs in alveolar septa was lower in newborns with RDS as compared to newborns with RDS combined with pneumonia (2.83 ± 1.13 vs 4.81 ± 2.6, p < 0.001). The amount of Try+ MCs along bronchial wall was significantly more than GHR+ MCs in RDS newborns (6.97 ± 4.53 vs 3.85 ± 4.30, p = 0.001). It could be supposed that pulmonary MCs increased in newborn lungs in inflammatory process. MCs in human lung contained GHR peptide that had immunomodulatory function and participated in hormone regulation of inflammation.

Ghrelin receptor agonist hexarelin attenuates antinociceptive tolerance to morphine in rats

Ghrelin, a peptide hormone released from the gastric endocrine glands, shows analgesic activity apart from its various physiological effects. Nevertheless, the effects of ghrelin receptor (GHS-R) agonists on morphine analgesia and tolerance have not yet been elucidated. The purpose of this study was to evaluate the effects of the ghrelin receptor agonist hexarelin and antagonist [d-Lys3]-GHRP-6 on morphine antinociception and tolerance in rats. A total of 104 Wistar albino male adult rats (weighing approximately 220-240 g) were used in the experiments. To induce morphine tolerance, a three-day cumulative dose regimen was used in the rats. Then, randomly selected rats were evaluated for morphine tolerance on day 4. The analgesic effects of hexarelin (0.2 mg·kg-1), [d-Lys3]-GHRP-6 (10 mg·kg-1), and morphine (5 mg·kg-1) were measured at 30-min intervals (0, 30, 60, 90, and 120 min) by tail-flick and hot-plate analgesia tests. The findings suggest that hexarelin in combination with morphine attenuates analgesic tolerance to morphine. On the other hand, ghrelin receptor antagonist [d-Lys3]-GHRP-6 has no significant analgesic activity on the morphine tolerance in analgesia tests. Furthermore, co-administration of hexarelin and morphine increases the analgesic effect. In conclusion, these data indicate that administration of GHS-R agonist hexarelin with morphine enhances the antinociception and attenuates morphine tolerance.

Potential Antioxidative, Anti-inflammatory and Immunomodulatory Effects of Ghrelin, an Endogenous Peptide from the Stomach in SARS-CoV2 Infection

The current COVID-19 pandemic is one of the most devastating events in recent history. The respiratory effects of this disease include acute respiratory distress syndrome, systemic inflammation, cytokine storm, and pulmonary fibrosis. Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor, is a peptide hormone secreted mainly by the stomach. Interestingly, ghrelin possesses promising antioxidant, anti-and inflammatory effects, making it an attractive agent to reduce the complications of the SARS-CoV-2. In addition, ghrelin exerts a wide range of immunomodulatory and anti-inflammatory effects and can mitigate the uncontrolled cytokine production responsible for acute lung injury by upregulating PPARγ and down-regulating NF-κB expression. Ghrelin has also been reported to enhance Nrf2 expression in inflammatory conditions which led to the suppression of oxidative stress. The current opinion summarizes the evidence for the possible pharmacological benefits of ghrelin in the therapeutic management of SARS-CoV-2 infection.

Growth Hormone Releasing Hormone Reduces Circulating Markers of Immune Activation in Parallel with Effects on Hepatic Immune Pathways in Individuals with HIV-Infection and Nonalcoholic Fatty Liver Disease

BACKGROUND

The growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis modulates critical metabolic pathways; however, little is known regarding effects of augmenting pulsatile GH secretion on immune function in humans. This study used proteomics and gene set enrichment analysis to assess effects of a GH releasing hormone (GHRH) analog, tesamorelin, on circulating immune markers and liver tissue in people with HIV (PWH) and NAFLD.

METHODS

92 biomarkers associated with immunity, chemotaxis, and metabolism were measured in plasma samples from 61 PWH with NAFLD who participated in a double-blind, randomized trial of tesamorelin versus placebo for 12 months. Gene set enrichment analysis was performed on serial liver biopsies targeted to immune pathways.

RESULTS

Tesamorelin, compared to placebo, decreased interconnected proteins related to cytotoxic T-cell and monocyte activation. Circulating concentrations of 13 proteins were significantly decreased, and no proteins increased, by tesamorelin. These included four chemokines (CCL3, CCL4, CCL13 [MCP4], IL8 [CXCL8]), two cytokines (IL-10 and CSF-1), and four T-cell associated molecules (CD8A, CRTAM, GZMA, ADGRG1), as well as ARG1, Gal-9, and HGF. Network analysis indicated close interaction among the gene pathways responsible for these proteins, with imputational analyses suggesting down regulation of a closely related cluster of immune pathways. Targeted transcriptomics using liver tissue confirmed a significant end-organ signal of down-regulated immune activation pathways.

CONCLUSIONS

Long-term treatment with a GHRH analog reduced markers of T-cell and monocyte/macrophage activity, suggesting that augmentation of the GH axis may ameliorate immune activation in an HIV population with metabolic dysregulation, systemic and end organ inflammation.

Ghrelin Inhibits Intestinal Epithelial Cell Apoptosis Through the Unfolded Protein Response Pathway in Ulcerative Colitis

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) that occurs in the lining of the rectum and colon. Apoptosis of the intestinal epithelial cells (IECs) is common in active UC patients. Ghrelin is reported to be downregulated in apoptosis of IECs induced by tumor necrosis factor-α (TNF-α). Therefore, we hypothesized that ghrelin might play an antiapoptotic role in UC progression, which was investigated using in vitro and in vivo studies. The TNF-α-treated Caco-2 cell model and mouse colitis model induced by dextran sulfate sodium (DSS) or 2,4,6-trinitrobenzenesulfonic acid (TNBS) were established and employed. We found that ghrelin could inhibit the apoptosis of Caco-2 cells induced by TNF-α, which could be disturbed by [D-lys3]-GHRP-6, the antagonist of ghrelin receptor GHS-R1a. Similarly, in the DSS- and TNBS-induced mouse colitis models, ghrelin could also protect intestinal tissues from apoptosis in DSS- and TNBS-induced colitis depending on GHS-R1a. Furthermore, ghrelin modulated the unfolded protein response (UPR) pathway and regulated the expressions of caspase-3, BAX, and Bcl-2, which contributed to the inhibition of cell apoptosis. In conclusion, ghrelin protects IECs from apoptosis during the pathogenesis of colitis by regulating the UPR pathway.

Chronic inflammation and the growth hormone/insulin-like growth factor-1 axis

Interactions between growth hormone (GH), insulin-like growth factor-1 (IGF-1), and the immune system are complex, bidirectional, but not fully explained. Current reviews based on numerous studies have indicated that chronic inflammation could suppress the GH/IGF-1 axis via several mechanisms such as relative GH and/or IGF-1 insufficiency, peripheral resistance to GH and/or IGF-1 resulting from down-regulation of GH and IGF-1 receptors, disruption in the GH/IGF-1 signalling pathways, dysregulation of IGF binding proteins (IGFBPs), reduced IGF bioavailability, and modified gene regulation due to changes in the microRNA system. It is well-known that relationships between the immune system and the GH/IGF-1 axis are mutual and GH as well as IGF-1 could modulate inflammatory response and the activity of systemic inflammation. Available data indicate that the GH/IGF-1 axis exerts both pro-inflammatory and anti-inflammatory effects. Pro-inflammatory cytokines such as interleukin-6 (IL-6), tumour necrosis factor-a (TNF-α), and interleukin-1b (IL-b) are some of the most significant factors, besides malnutrition, chronic stress, and prolonged use of glucocorticoids, which impair the activity of the GH/IGF-1 axis, and consequently lead to growth retardation in children suffering from childhood-onset chronic inflammatory diseases. In this review, we discuss the mechanisms underlying the impact of chronic inflammation on the GH/IGF-1 axis and growth processes during childhood and adolescence, based on a number of experimental and human studies.

Tryptase- and ghrelin positive mast cells in the interalveolar septa of rat’s lung

The mast cell mediators and distribution of lung mast cells in rats are often discussed in experimental studies on pulmonary fibrotic and allergic processes associated with changes in numbers of these cells, but information on the normal distribution of metachromatic and tryptase-positive mast cells in the interalveolar septa is scarce. There are no data on the presence of ghrelin in lung mast cells as well as the age-specific features of localisation and the number of mast cells in the interalveolar septa in rats of different ages. Therefore, the purpose of the present study was to determine the distribution of metachromatic, tryptase-, and ghrelin-positive mast cells in the interalveolar septa in 20 day-, 3 month- and 1 year-old rats. Tissue sections stained with toluidine blue had been taken from the left lung to visualise metachromasia and immunohistochemical expression of tryptase and ghrelin. The results showed that the amount of metachromatic mast cells in the interalveolar septa was significantly lower than that of tryptase- and ghrelin-positive cells. This allowed suggesting that mast cells were permanent occupants of the rat lung parenchyma and, on the other hand, the expression of ghrelin in their granules was most likely related to the synthesis of this protein. Our study showed that immunohistochemical identification by tryptase expression was more accurate than toluidine blue staining.

Growth hormone (GH) and growth hormone release factor (GRF) modulate the immune response in the SHK-1 cell line and leukocyte cultures of head kidney in Atlantic salmon

To clarify the role of growth hormone (GH) in the immune system of fish, we examine the comparative effect of GH and Growth Hormone Release Factor (GRF) on leukocytes culture of the head kidney of Atlantic salmon and the SHK-1 cell line. There are studies that associate the growth hormone (GH) / insulin-like growth factor (IGF) axis with the immune regulation of fish. However, there is no evidence that GH and GRF stimulate Atlantic salmon leukocyte cell lines, where there areńt reports on expression changes in different immune response markers. Thus, we investigated the effect of GH and GRF in Atlantic salmon leukocytes extracted from head kidney and the SHK-1 cell line on the different immune response markers such as: NLRC5, NLRC3, IL-1β, TNF-α, and IL-8 through qPCR. Our data suggest that GH increases the expression of NLRC5, NLRC3, and IL-1β mainly at 16 h post-stimulation in Atlantic salmon leukocytes. This indicates differential regulation between the two models used, helping us to better understand the independent action of GH on the immune system and the GH / IGF axis for future research.

Co-Occurrence of ANCA-Associated Vasculitis and Sjögren's Syndrome in a Patient With Acromegaly: A Case Report and Retrospective Single-Center Review of Acromegaly Patients

Background

ANCA-associated vasculitis (AAV) and Sjögren’s syndrome (SS) are uncommon autoimmune diseases. The co-occurrence in the same patient has been rarely described. Acromegaly has been associated with autoimmune thyroiditis, but the prevalence of other autoimmune disorders such as AAV and SS has not been evaluated in acromegaly.

Methods

Characterization of a patient with acromegaly and two rare autoimmune diseases—SS and AAV (microscopic polyangiitis (MPA))—by autoantibody-array and whole exome sequencing (WES). Single-center retrospective review of medical records of acromegaly patients to explore the prevalence of diagnosed autoimmune diseases.

Results

We report a Caucasian woman in her 50’s with a serologically (anti-SSA/Ro, anti-MPO-ANCA antibodies) and histologically confirmed diagnosis of symptomatic SS and MPA. SS with MPO-ANCA positivity preceded MPA. An exploratory autoantigen array detected a broad spectrum of autoantibodies. WES revealed heterozygous carrier status of the PTPN22 mutation R620W, which is associated with an increased risk for autoimmunity. A similar combination of positive anti-SSA/Ro autoantibodies and ANCA was only present in 5/1184 (0.42%) other patients tested for both antibodies in our clinic over six years. Amongst 85 acromegaly patients seen at our clinic in a 20-year period, 12% had a clinically relevant associated immunological disease.

Conclusion

We present a rare case of SS and AAV in a patient with acromegaly and multiple autoantibody specificities. Patients with SS and ANCA should be closely monitored for the development of (subclinical) AAV. Whether acromegaly represents a risk for autoimmunity should be further investigated in prospective acromegaly cohorts.

Growth Hormone Receptor Regulation in Cancer and Chronic Diseases

The GHR signaling pathway plays important roles in growth, metabolism, cell cycle control, immunity, homeostatic processes, and chemoresistance via both the JAK/STAT and the SRC pathways. Dysregulation of GHR signaling is associated with various diseases and chronic conditions such as acromegaly, cancer, aging, metabolic disease, fibroses, inflammation and autoimmunity. Numerous studies entailing the GHR signaling pathway have been conducted for various cancers. Diverse factors mediate the up- or down-regulation of GHR signaling through post-translational modifications. Of the numerous modifications, ubiquitination and deubiquitination are prominent events. Ubiquitination by E3 ligase attaches ubiquitins to target proteins and induces proteasomal degradation or starts the sequence of events that leads to endocytosis and lysosomal degradation. In this review, we discuss the role of first line effectors that act directly on the GHR at the cell surface including ADAM17, JAK2, SRC family member Lyn, Ubc13/CHIP, proteasome, βTrCP, CK2, STAT5b, and SOCS2. Activity of all, except JAK2, Lyn and STAT5b, counteract GHR signaling. Loss of their function increases the GH-induced signaling in favor of aging and certain chronic diseases, exemplified by increased lung cancer risk in case of a mutation in the SOCS2-GHR interaction site. Insight in their roles in GHR signaling can be applied for cancer and other therapeutic strategies.

T cell regeneration after immunological injury

Following periods of haematopoietic cell stress, such as after chemotherapy, radiotherapy, infection and transplantation, patient outcomes are linked to the degree of immune reconstitution, specifically of T cells. Delayed or defective recovery of the T cell pool has significant clinical consequences, including prolonged immunosuppression, poor vaccine responses and increased risks of infections and malignancies. Thus, strategies that restore thymic function and enhance T cell reconstitution can provide considerable benefit to individuals whose immune system has been decimated in various settings. In this Review, we focus on the causes and consequences of impaired adaptive immunity and discuss therapeutic strategies that can recover immune function, with a particular emphasis on approaches that can promote a diverse repertoire of T cells through de novo T cell formation.

The relation between the ghrelin receptor and FOXP3 in bladder cancer

Immune responses play an important role in the fate of bladder cancer tumors. Treg cells are immunosuppressive and down-regulate the proliferation of effector T cells, which favor tumor survival. Ghrelin is a hormone that stimulates release of growth hormone and anti-inflammatory response to cancer cells. Ghrelin also is a gastrointestinal hormone that regulates immune responses via the growth hormone secretagogue receptor (GHS-R1a). The relation among ghrelin, its receptor, and Treg cells that surround bladder tumors is not clear. We found that Foxp3⁺ T and GHS-R1a cells are increased significantly in bladder tumor tissues. Therefore, we suggest that ghrelin may increase the number of Treg cells in the tumor and suppress activity of the immune system against bladder cancer.

Does Calorie Restriction Modulate Inflammaging via FoxO Transcription Factors?

Calorie restriction (CR) has been shown to extend lifespan and retard aging-related functional decline in animals. Previously, we found that the anti-neoplastic and lifespan-extending effects of CR in mice are regulated by forkhead box O transcription factors (FoxO1 and FoxO3), located downstream of growth hormone (GH)–insulin-like growth factor (IGF)-1 signaling, in an isoform-specific manner. Inflammaging is a term coined to represent that persistent low-level of inflammation underlies the progression of aging and related diseases. Attenuation of inflammaging in the body may underlie the effects of CR. Recent studies have also identified cellular senescence and activation of the nucleotide-binding domain, leucine-rich-containing family, pyrin-domain-containing-3 (NLRP3) inflammasome as causative factors of inflammaging. In this paper, we reviewed the current knowledge of the molecular mechanisms linking the effects of CR with the formation of inflammasomes, particularly focusing on possible relations with FoxO3. Inflammation in the brain that affects adult neurogenesis and lifespan was also reviewed as evidence of inflammaging. A recent progress of microRNA research was described as regulatory circuits of initiation and propagation of inflammaging. Finally, we briefly introduced our preliminary results obtained from the mouse models, in which Foxo1 and Foxo3 genes were conditionally knocked out in the myeloid cell lineage.

Why Should Growth Hormone (GH) Be Considered a Promising Therapeutic Agent for Arteriogenesis? Insights from the GHAS Trial

Despite the important role that the growth hormone (GH)/IGF-I axis plays in vascular homeostasis, these kind of growth factors barely appear in articles addressing the neovascularization process. Currently, the vascular endothelium is considered as an authentic gland of internal secretion due to the wide variety of released factors and functions with local effects, including the paracrine/autocrine production of GH or IGF-I, for which the endothelium has specific receptors. In this comprehensive review, the evidence involving these proangiogenic hormones in arteriogenesis dealing with the arterial occlusion and making of them a potential therapy is described. All the elements that trigger the local and systemic production of GH/IGF-I, as well as their possible roles both in physiological and pathological conditions are analyzed. All of the evidence is combined with important data from the GHAS trial, in which GH or a placebo were administrated to patients suffering from critical limb ischemia with no option for revascularization. We postulate that GH, alone or in combination, should be considered as a promising therapeutic agent for helping in the approach of ischemic disease.

Thyrotropin-Releasing Hormone (TRH) and Somatostatin (SST), but not Growth Hormone-Releasing Hormone (GHRH) nor Ghrelin (GHRL), Regulate Expression and Release of Immune Growth Hormone (GH) from Chicken Bursal B-Lymphocyte Cultures

It is known that growth hormone (GH) is expressed in immune cells, where it exerts immunomodulatory effects. However, the mechanisms of expression and release of GH in the immune system remain unclear. We analyzed the effect of growth hormone-releasing hormone (GHRH), thyrotropin-releasing hormone (TRH), ghrelin (GHRL), and somatostatin (SST) upon GH mRNA expression, intracellular and released GH, Ser133-phosphorylation of CREB (pCREB^S133), intracellular Ca²⁺ levels, as well as B-cell activating factor (BAFF) mRNA expression in bursal B-lymphocytes (BBLs) cell cultures since several GH secretagogues, as well as their corresponding receptors (-R), are expressed in B-lymphocytes of several species. The expression of TRH/TRH-R, ghrelin/GHS-R1a, and SST/SST-Rs (Subtypes 1 to 5) was observed in BBLs by RT-PCR and immunocytochemistry (ICC), whereas GHRH/GHRH-R were absent in these cells. We found that TRH treatment significantly increased local GH mRNA expression and CREB phosphorylation. Conversely, SST decreased GH mRNA expression. Additionally, when added together, SST prevented TRH-induced GH mRNA expression, but no changes were observed in pCREB^S133 levels. Furthermore, TRH stimulated GH release to the culture media, while SST increased the intracellular content of this hormone. Interestingly, SST inhibited TRH-induced GH release in a dose-dependent manner. The coaddition of TRH and SST decreased the intracellular content of GH. After 10 min. of incubation with either TRH or SST, the intracellular calcium levels significantly decreased, but they were increased at 60 min. However, the combined treatment with both peptides maintained the Ca²⁺ levels reduced up to 60-min. of incubation. On the other hand, BAFF cytokine mRNA expression was significantly increased by TRH administration. Altogether, our results suggest that TRH and SST are implicated in the regulation of GH expression and release in BBL cultures, which also involve changes in pCREB^S133 and intracellular Ca²⁺ concentration. It is likely that TRH, SST, and GH exert autocrine/paracrine immunomodulatory actions and participate in the maturation of chicken BBLs.

Intractable Chronic Granulomatous Perioral Dermatitis in Patients Receiving Growth Hormone Therapy: A New Association between CGPD and GH

Childhood granulomatous periorificial dermatitis (CGPD) is a self-limiting skin condition characterized by papular eruptions around the mouth, nose and eyes of preadolescent children. We report two cases of intractable CGPD in which patients receiving growth hormone (GH) therapy showed persistent symptoms despite multiple treatment modalities. This association may suggest the role of GH in the pathogenesis of CGPD.

Ghrelin induces autophagy and CXCR4 expression via the SIRT1/AMPK axis in lymphoblastic leukemia cell lines

T cell acute lymphoblastic leukemia (T-ALL) is one of the most frequent malignancies in children, and the CXCR4 receptor plays an important role in the metastasis of this malignancy. Ghrelin is a hormone with various functions including stimulation of the release of growth hormone and autophagy in cancer cells. Moreover, SIRT1 and AMPK (AMP-activated protein kinase) stimulate expression of proteins involved in autophagy. On the other hand, autophagic cell death can be an alternative target for cancer therapy, in the absence of apoptosis. The relationship between ghrelin and the SIRT1/AMPK axis and the resulting effects on autophagy, apoptosis, proliferation, and expression of CXCR4 and the ghrelin receptor (GHS-R1a), in Jurkat and Molt-4 human lymphoblastic cell lines was not previously clear. Here we demonstrate that SIRT1 expression is upregulated during the induction of autophagy by ghrelin, an effect that is inhibited by inactivation of SIRT1/AMPK axis. In addition, ghrelin can affect CXCR4 and GHS-R1a expression. In conclusion, this work reveals that ghrelin induces autophagy, invasion, and downregulation of ghrelin receptor expression via the SIRT1/AMPK axis in lymphoblastic cell lines. However, in these cell lines ghrelin-induced autophagy does not lead to cell death due to weak induction of apoptosis.

Correlations between the Peptide Hormone Ghrelin and Proinflammatory Cytokines in Experimental Periodontitis Models of Female Rats at Different Stages of the Life Cycle

OBJECTIVE

The aim of this study was to examine the correlations between the levels of ghrelin and inflammatory and bone metabolism markers in rats with periodontitis.

DESIGN

Thirty female Wistar rats (6 trial rats and 4 control rats in each group) were divided into pubertal, adult and postmenopausal groups. Periodontitis was induced by ligatures. On the 21 st day, blood was collected and all rats were then sacrificed. The levels of osteocalcin, osteoprotegerin, alkaline phosphatase, tumour necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), acylated ghrelin, total ghrelin and soluble receptor activator of nuclear factor-kB ligands in the blood samples were measured using enzyme-linked immunosorbent assays. The jaws were decalcified in a Tris-EDTA solution and embedded in paraffin and 4-5 μm sections were cut for IL-β, TNF -α and ghrelin staining.

RESULTS

Significantly higher serum alkaline phosphatase levels were detected in the trial rats in the pubertal group than in the control rats (p = 0.033). In the postmenopausal group, ghrelin levels positively correlated with interleukin 1 beta levels (r = 0.708, p < 0.05). Among all trial rats, the postmenopausal group exhibited significantly higher levels of acylated ghrelin than the other groups (p = 0.001). Significantly higher osteoprotegerin levels were observed in the control rats than in the trial rats in the postmenopausal group (p = 0.012). Inflammation scores were significantly higher in adult trial rats than in controls (p = 0.024); significantly higher TNF-α levels were detected in postmenopausal experimental rats than in the adult experimental group (p = 0.025).

CONCLUSIONS

We concluded that total ghrelin levels in serum only correlated with IL-β levels in postmenopausal rats.

Attenuated levels of ghrelin in synovial fluid is related to the disease severity of ankle post-traumatic osteoarthritis

Post-traumatic osteoarthritis (PTOA) of ankle joints results in pain and reduced joint function. Ghrelin, a 28-amino-acid polypeptide, has been previously identified as the first cognate natural ligand that binds to the growth hormone secretagogue receptor. In the present study, ghrelin has been validated to exert cartilage-protective and anti-inflammatory effects. The current study was aimed at investigating the potential role of the levels of serum and synovial fluid (SF) ghrelin on the severity of disease in patients suffering from ankle PTOA. Ninety-seven patients with ankle osteoarthritis who received an arthroscopical examination and debridement or replacement of the ankle joint were included in the study cohort. Meanwhile, 95 healthy individuals (whose age and sex were matched) who received periodic body checkups were enrolled as healthy controls. Enzyme-linked immunosorbent assay (ELISA) was used to analyze the ghrelin levels in serum and SF. SF was also probed for cartilage degradation enzyme matrix metalloproteinases-3 (MMP-3) and tumor necrosis factor alpha (TNF-α), which is a known pro-inflammatory cytokine. The clinical evaluation was carried out using the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot rating scale and visual analogue scale (VAS). The radiographic severity was evaluated using the modified Kellgren-Lawrence (K-L) grading system. We scored for the modified Mankin's score to depict histopathological changes due to cartilage lesions. The diagnostic relevance of the ghrelin concentrations in the prediction of the radiographic grading (in comparison with MMP-3 and TNF-α) was evaluated by calculating the area under the curve of the receiver operating characteristic (ROC) curve. The serum abundance of ghrelin was not significantly altered between ankle PTOA patients and healthy controls. SF ghrelin was negatively correlated with radiographic progression determined by modified ankle K-L grades. In addition SF ghrelin concentrations were negatively related to VAS scores, and positively associated with AOFAS ankle-hindfoot rating. Moreover, SF ghrelin was inversely proportional to the expressions of MMP-3 and TNF-α. ROC analysis curve demonstrated that ghrelin serves as a favorable marker for the diagnosis of radiographic severity by modified ankle K-L grade. The ghrelin concentration in SF is negatively proportional to disease progression in patients suffering from ankle PTOA. Local administration of ghrelin may function as a decent adjuvant therapy to delay the progress of ankle PTOA. © 2019 BioFactors, 45(3):463-470, 2019.

Potential Therapeutic Effects of Gut Hormones, Ghrelin and Obestatin in Oral Mucositis

Chemotherapy and/or head and neck radiotherapy are frequently associated with oral mucositis. Oral pain, odynophagia and dysphagia, opioid use, weight loss, dehydration, systemic infection, hospitalization and introduction of a feeding tube should be mentioned as the main determinated effect of oral mucositis. Oral mucositis leads to a decreased quality of life and an increase in treatment costs. Moreover, oral mucositis is a life-threatening disease. In addition to its own direct life-threatening consequences, it can also lead to a reduced survival due to the discontinuation or dose reduction of anti-neoplasm therapy. There are numerous strategies for the prevention or treatment of oral mucositis; however, their effectiveness is limited and does not correspond to expectations. This review is focused on the ghrelin and obestatin as potentially useful candidates for the prevention and treatment of chemo- or/and radiotherapy-induced oral mucositis.

Adipocyte-Specific GH Receptor-Null (AdGHRKO) Mice Have Enhanced Insulin Sensitivity With Reduced Liver Triglycerides

Global GH receptor-null or knockout (GHRKO) mice have been extensively studied owing to their unique phenotype (dwarf and obese but remarkably insulin sensitive and long-lived). To better understand the influence of adipose tissue (AT) on the GHRKO phenotype, we previously generated fat-specific GHRKO (FaGHRKO) mice using the adipocyte protein-2 (aP2) promoter driving Cre expression. Unlike global GHRKO mice, FaGHRKO mice are larger than control mice and have an increase in white AT (WAT) mass and adipocyte size as well as an increase in brown AT mass. FaGHRKO mice also have an unexpected increase in IGF-1, decrease in adiponectin, no change in insulin sensitivity or liver triglyceride content, and a decreased lifespan. Extensive analysis of the aP2 promoter/enhancer by multiple laboratories has revealed expression in nonadipose tissues, confounding interpretation of results. In the current study, we used the adiponectin promoter/enhancer to drive Cre expression, which better targets mature adipocytes, and generated a new line of adipocyte-specific GHRKO (AdGHRKO) mice. AdGHRKO mice have an increase in adipocyte size and WAT depot mass in all depots except male perigonadal, a WAT accumulation pattern similar to FaGHRKO mice. Likewise, adiponectin levels and WAT fibrosis are decreased in both tissue-specific mouse lines. However, unlike FaGHRKO mice, AdGHRKO mice have no change in IGF-1 levels, improved glucose homeostasis, and reduced liver triglycerides. Thus, AdGHRKO mice should be valuable for future studies assessing the contribution of adipocyte GHR signaling in long-term health and lifespan.

Morphofunctional parameters of rat somatotrophes after acute and repeated immobilization or restraint stress

It is well known that stress changes levels of pituitary hormones in the bloodstream and in the pituitary itself. However, almost nothing is known about the impact of stress on histological and stereological parameters of the growth hormone producing cells (somatotrophs-GH cells). The aim of the present study was to investigate the effect of: acute and repeated immobilization; acute and repeated restraint on histological and morphofunctional parameters of somatotrophs in adult Wistar rats. Changes in the pituitary gland volume; the volume density and volume of somatotrophs following acute and repeated immobilization (IMO, R-IMO); acute and repeated restraint (R, R-R) were evaluated using a stereological system (newCAST), while growth hormone level within pituitary was determined by Western blot. Our results demonstrated the decrease (p < 0.05) of the pituitary volume (17%, 19%) in the IMO and R groups, respectively, and the increase in the R-R group. The volume density of GH cells decreased (p < 0.05) in the R-IMO (7%), R (26%) and R-R (18%) group in comparison to the control value. The pituitary GH content was increased (p < 0.05) after the IMO (2-fold), R (2.5-fold) and R-R (2.1-fold) as compared to the control group. These results point out that acute and repeated immobilization and/or restraint lead not only to changes in GH hormone concentration, but also modify the morphological aspects of GH cells within the rat pituitary.

Acylated ghrelin suppresses the cytokine response to lipopolysaccharide and does so independently of the hypothalamic-pituitary-adrenal axis

Ghrelin, one of the major metabolic hormones involved in controlling energy balance, has recently been shown to have other properties including regulating the hypothalamic-pituitary-adrenal (HPA) axis response to psychological stress and being a potent anti-inflammatory agent. Ghrelin's HPA axis and anti-inflammatory actions have previously been identified as principally due to the acylated form (AG). However, our recent work has also suggested a role for des-acylated ghrelin (DAG) in these functions. Here we hypothesized ghrelin's anti-inflammatory activity is mediated by the HPA axis and this effect is differentially executed by AG and DAG. We gave adult male Wistar rats a concomitant injection of AG or DAG and lipopolysaccharide (LPS) and measured their effects on circulating cytokines, stress hormones and neuronal activation of the paraventricular nucleus of the hypothalamus (PVN). AG, but not DAG significantly suppressed the pro- and anti-inflammatory cytokine response induced by LPS in vivo. DAG also had no effects on any components of the HPA axis. AG, despite stimulating neuronal activation in the PVN in vivo and stimulating ACTH release from the pituitary in vitro, did not affect the HPA axis response to LPS. These findings suggest AG's anti-inflammatory effects are independent of its actions on the HPA axis and have implications for the potential use of this peptide for treatment of inflammatory conditions without compromising HPA axis activity.

Adipokines in critical illness: A review of the evidence and knowledge gaps

Adipose tissue products or adipokines play a major role in chronic endocrine and metabolic disorders; however, little is known about critical conditions. In this article, the experimental and clinical evidence of alterations of adipokines, adiponectin, leptin, resistin, visfatin, asymmetric dimethylarginine (ADMA), and ghrelin in critical illness, their potential metabolic, diagnostic, and prognostic value, and the gaps in the field have been reviewed. The results showed considerable changes in the concentration of the adipokines; while the impact of adipokines on metabolic disorders such as insulin resistance and inflammation has not been well documented in critically ill patients. There is no consensus about the circulatory and functional changes of leptin and adiponectin. However, it seems that lower concentrations of adiponectin at admission with gradual consequent increase might be a useful pattern in determining better outcomes of critical illness. Some evidence has suggested the adverse effects of elevated resistin concentration, potential prognostic importance of visfatin, and therapeutic value of ghrelin. High ADMA levels and low arginine:ADMA ratio were also proposed as predictors of ICU mortality and morbidities. However, there is no consensus on these findings. Although primary data indicated the role of adipokines in critical illness, further studies are required to clarify whether the reason of these changes is pathophysiological or compensatory. The relationship of pathophysiological background, disease severity, baseline nutritional status and nutrition support during hospitalization, and variations in body fat percentage and distribution with adipokines, as well as the potential prognostic or therapeutic role of these peptides should be further investigated in critically ill patients.

Immunological and microbiological periodontal profiles in isolated growth hormone deficiency

BACKGROUND

Growth hormone (GH) has been identified as an important regulator of the immune response. We have previously shown that adults with isolated GH deficiency (IGHD) due to a mutation in the GH releasing hormone receptor (GHRHR) gene, have a greater chance of having periodontitis. However, the interaction of GH with periodontal tissues is still unknown, and this population has emerged as a unique model to investigate this issue. Therefore, we evaluated the microbiological and immunological periodontal profiles of such individuals.

METHODS

Nineteen IGHD and 19 controls matched by age, sex, diabetes, and smoking status, were enrolled in this case-control study. Periodontal clinical parameters (probing depth [PD] and clinical attachment loss [AL]) were measured at six sites per tooth. Immune mediators (C-reactive protein, matrix metalloproteinase [MMP]-8, MMP-9, interleukin [IL]-1α, IL-6, IL-8, tumor necrosis factor [TNF]-α, adiponectin, and leptin) were analyzed by enzyme-linked immunosorbent assay (ELISA) in the gingival crevicular fluid (GCF) in four non-adjacent sites for each participant (two with PD ≤3 mm [shallow sites] and two with PD ≥7 mm or the worst PD found in the mouth [deep sites]). Bacterial quantification (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia) of subgingival biofilm samples collected from these same sites was performed by quantitative real-time polymerase chain reaction (qPCR).

RESULTS

IGHD individuals presented higher values of PD and AL, and increased levels of CRP, IL-8, MMP-8, and adiponectin in the GCF. Bacterial quantification did not identify differences between the two groups.

CONCLUSION

IGHD alters the local immune response in periodontal pockets leading to greater attachment loss, and GH stands out as an important hormone to be evaluated in the pathogenesis of periodontitis.

The Growth Hormone Receptor: Mechanism of Receptor Activation, Cell Signaling, and Physiological Aspects

The growth hormone receptor (GHR), although most well known for regulating growth, has many other important biological functions including regulating metabolism and controlling physiological processes related to the hepatobiliary, cardiovascular, renal, gastrointestinal, and reproductive systems. In addition, growth hormone signaling is an important regulator of aging and plays a significant role in cancer development. Growth hormone activates the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway, and recent studies have provided a new understanding of the mechanism of JAK2 activation by growth hormone binding to its receptor. JAK2 activation is required for growth hormone-mediated activation of STAT1, STAT3, and STAT5, and the negative regulation of JAK-STAT signaling comprises an important step in the control of this signaling pathway. The GHR also activates the Src family kinase signaling pathway independent of JAK2. This review covers the molecular mechanisms of GHR activation and signal transduction as well as the physiological consequences of growth hormone signaling.

Nicorandil and theophylline can protect experimental rats against complete Freund's adjuvant-induced rheumatoid arthritis through modulation of JAK/STAT/RANKL signaling pathway

Signaling pathways are interesting fields of study of pathogenesis and treatment trials. We elucidated the possible protective effects of nicorandil (15mg/kg/day) and theophylline (20mg/kg/day) on experimentally-induced RA, focusing on the role of JAK (Janus Kinase) / STAT (Signal Transducer and Activator of Transcription) / RANKL (Receptor Activator of Nuclear factor-Kappa B Ligand) / cytokine signaling pathway. Four sets of experiments were performed. First, effect of test agents on normal animals was evaluated. Second, effect of test agents was evaluated on Complete Freund's Adjuvant (CFA; 0.3ml, s.c.)-induced RA to investigate anti-arthritic effect. Third, effect of test agents was evaluated on growth hormone (GH; 2mg/kg/day, s.c.)-induced stimulation of JAK/STAT/RANKL/cytokine signaling pathway to investigate the role of this signaling pathway in their anti-arthritic effect. Fourth, the effect of test agents was performed on CFA/GH-induced RA. To fulfill this purpose, serum anti-citrullinated peptide antibody (ACPA), interleukin-6 (IL-6), and cartilage oligomeric matrix protein (COMP), together with tissue JAK2, STAT3, RANKL, inducible and endothelial nitric oxide synthases (iNOS and eNOS) as well as macrophage inflammatory protein (MIP_1α) were estimated using ELISA, Western blotting and PCR techniques, confirmed by a histopathological study. Test agents significantly corrected JAK2, STAT3, RANKL and IL-6 values in animals receiving GH. Additionally, test agents could correct ACPA, IL-6, COMP, JAK2, STAT3, RANKL, iNOS, eNOS and MIP_1α levels compared with the respective CFA or CFA/GH controls. These results conclude that nicorandil and theophylline have good anti-arthritic effects related to modulation of JAK/STAT/RANKL signaling pathway. Further clinical trials are claimed.