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The Lancet. Diabetes & Endocrinology Sep 2018Frailty is a condition characterised by loss of biological reserves, failure of homoeostatic mechanisms, and vulnerability to adverse outcomes. The endocrine system is... (Review)
Review
Frailty is a condition characterised by loss of biological reserves, failure of homoeostatic mechanisms, and vulnerability to adverse outcomes. The endocrine system is considered particularly important in frailty, because of its complex inter-relationships with the brain, immune system, and skeletal muscle. This Review summarises evidence indicating a key role for the hypothalamic-pituitary axis in the pathogenesis of frailty through aberrant regulation of glucocorticoid secretion, insulin-like growth factor signalling, and androgen production. Evidence also indicates a potential role for vitamin D and insulin resistance in the pathogenesis of frailty. The role of thyroid hormones in the pathogenesis of frailty remains uncertain. Key convergent pathological effects of frailty include loss of muscle mass and strength, with consequent impact on mobility and activities of daily living. Future translational research should focus on the understanding of endocrine mechanisms, to identify potential biomarkers of the condition, modifiable targets for treatment, and novel pharmacological drugs targeted at the endocrine components of frailty.
Topics: Aged; Aging; Androgens; Endocrine System; Frailty; Glucocorticoids; Humans; Insulin Resistance; Sarcopenia; Signal Transduction; Somatomedins; Vitamin D
PubMed: 30017798
DOI: 10.1016/S2213-8587(18)30110-4 -
Hormone Research in Paediatrics 2016On behalf of the Drug and Therapeutics, and Ethics Committees of the Pediatric Endocrine Society, we sought to update the guidelines published in 2003 on the use of...
Guidelines for Growth Hormone and Insulin-Like Growth Factor-I Treatment in Children and Adolescents: Growth Hormone Deficiency, Idiopathic Short Stature, and Primary Insulin-Like Growth Factor-I Deficiency.
BACKGROUND/AIMS
On behalf of the Drug and Therapeutics, and Ethics Committees of the Pediatric Endocrine Society, we sought to update the guidelines published in 2003 on the use of growth hormone (GH). Because idiopathic short stature (ISS) remains a controversial indication, and diagnostic challenges often blur the distinction between ISS, GH deficiency (GHD), and primary IGF-I deficiency (PIGFD), we focused on these three diagnoses, thereby adding recombinant IGF-I therapy to the GH guidelines for the first time.
METHODS
This guideline was developed following the GRADE approach (Grading of Recommendations, Assessment, Development, and Evaluation).
RESULTS
This guideline provides recommendations for the clinical management of children and adolescents with growth failure from GHD, ISS, or PIGFD using the best available evidence.
CONCLUSION
The taskforce suggests that the recommendations be applied in clinical practice with consideration of the evolving literature and the risks and benefits to each individual patient. In many instances, careful review highlights areas that need further research.
Topics: Adolescent; Child; Child, Preschool; Female; Growth Disorders; Human Growth Hormone; Humans; Infant; Insulin-Like Growth Factor I; Male
PubMed: 27884013
DOI: 10.1159/000452150 -
Frontiers in Endocrinology 2020Hormones are largely responsible for the integrated communication of several physiological systems responsible for modulating cellular growth and development. Although... (Review)
Review
Hormones are largely responsible for the integrated communication of several physiological systems responsible for modulating cellular growth and development. Although the specific hormonal influence must be considered within the context of the entire endocrine system and its relationship with other physiological systems, three key hormones are considered the "anabolic giants" in cellular growth and repair: testosterone, the growth hormone superfamily, and the insulin-like growth factor (IGF) superfamily. In addition to these anabolic hormones, glucocorticoids, mainly cortisol must also be considered because of their profound opposing influence on human skeletal muscle anabolism in many instances. This review presents emerging research on: (1) Testosterone signaling pathways, responses, and adaptations to resistance training; (2) Growth hormone: presents new complexity with exercise stress; (3) Current perspectives on IGF-I and physiological adaptations and complexity these hormones as related to training; and (4) Glucocorticoid roles in integrated communication for anabolic/catabolic signaling. Specifically, the review describes (1) Testosterone as the primary anabolic hormone, with an anabolic influence largely dictated primarily by genomic and possible non-genomic signaling, satellite cell activation, interaction with other anabolic signaling pathways, upregulation or downregulation of the androgen receptor, and potential roles in co-activators and transcriptional activity; (2) Differential influences of growth hormones depending on the "type" of the hormone being assayed and the magnitude of the physiological stress; (3) The exquisite regulation of IGF-1 by a family of binding proteins (IGFBPs 1-6), which can either stimulate or inhibit biological action depending on binding; and (4) Circadian patterning and newly discovered variants of glucocorticoid isoforms largely dictating glucocorticoid sensitivity and catabolic, muscle sparing, or pathological influence. The downstream integrated anabolic and catabolic mechanisms of these hormones not only affect the ability of skeletal muscle to generate force; they also have implications for pharmaceutical treatments, aging, and prevalent chronic conditions such as metabolic syndrome, insulin resistance, and hypertension. Thus, advances in our understanding of hormones that impact anabolic: catabolic processes have relevance for athletes and the general population, alike.
Topics: Adaptation, Physiological; Animals; Exercise; Growth Hormone; Growth and Development; Humans; Hydrocortisone; Muscle, Skeletal; Somatomedins; Testosterone
PubMed: 32158429
DOI: 10.3389/fendo.2020.00033 -
Cells Jun 2022In the 30 years since the first report of parental imprinting in insulin-like growth factor 2 () knockout mouse models, we have learnt much about the structure of this... (Review)
Review
In the 30 years since the first report of parental imprinting in insulin-like growth factor 2 () knockout mouse models, we have learnt much about the structure of this protein, its role and regulation. Indeed, many animal and human studies involving innovative techniques have shed light on the complex regulation of expression. The physiological roles of IGF-II have also been documented, revealing pleiotropic tissue-specific and developmental-stage-dependent action. Furthermore, in recent years, animal studies have highlighted important interspecies differences in IGF-II function, gene expression and regulation. The identification of human disorders due to impaired gene expression has also helped to elucidate the major role of IGF-II in growth and in tumor proliferation. The Silver-Russell and Beckwith-Wiedemann syndromes are the most representative imprinted disorders, as they constitute both phenotypic and molecular mirrors of -linked abnormalities. The characterization of patients with either epigenetic or genetic defects altering expression has confirmed the central role of IGF-II in human growth regulation, particularly before birth, and its effects on broader body functions, such as metabolism or tumor susceptibility. Given the long-term health impact of these rare disorders, it is important to understand the consequences of defects in these patients.
Topics: Animals; Beckwith-Wiedemann Syndrome; Epigenomics; Genomic Imprinting; Humans; Insulin-Like Growth Factor II; Mice; Silver-Russell Syndrome
PubMed: 35741015
DOI: 10.3390/cells11121886 -
Cells Jun 2021Growth hormone (GH) and insulin-like growth factor-1 (IGF-I) are pleiotropic hormones with important roles in lifespan. They promote growth, anabolic actions, and body... (Review)
Review
Growth hormone (GH) and insulin-like growth factor-1 (IGF-I) are pleiotropic hormones with important roles in lifespan. They promote growth, anabolic actions, and body maintenance, and in conditions of energy deprivation, favor catabolic feedback mechanisms switching from carbohydrate oxidation to lipolysis, with the aim to preserve protein storages and survival. IGF-I/insulin signaling was also the first one identified in the regulation of lifespan in relation to the nutrient-sensing. Indeed, nutrients are crucial modifiers of the GH/IGF-I axis, and these hormones also regulate the complex orchestration of utilization of nutrients in cell and tissues. The aim of this review is to summarize current knowledge on the reciprocal feedback among the GH/IGF-I axis, macro and micronutrients, and dietary regimens, including caloric restriction. Expanding the depth of information on this topic could open perspectives in nutrition management, prevention, and treatment of GH/IGF-I deficiency or excess during life.
Topics: Caloric Restriction; Carbohydrate Metabolism; Human Growth Hormone; Humans; Insulin-Like Growth Factor I; Lipolysis; Micronutrients; Signal Transduction
PubMed: 34199514
DOI: 10.3390/cells10061376 -
European Heart Journal Dec 2022Sodium-glucose co-transporter 2 (SGLT2) inhibitors improve cardiovascular outcomes in diverse patient populations, but their mechanism of action requires further study.... (Randomized Controlled Trial)
Randomized Controlled Trial
AIMS
Sodium-glucose co-transporter 2 (SGLT2) inhibitors improve cardiovascular outcomes in diverse patient populations, but their mechanism of action requires further study. The aim is to explore the effect of empagliflozin on the circulating levels of intracellular proteins in patients with heart failure, using large-scale proteomics.
METHODS AND RESULTS
Over 1250 circulating proteins were measured at baseline, Week 12, and Week 52 in 1134 patients from EMPEROR-Reduced and EMPEROR-Preserved, using the Olink® Explore 1536 platform. Statistical and bioinformatical analyses identified differentially expressed proteins (empagliflozin vs. placebo), which were then linked to demonstrated biological actions in the heart and kidneys. At Week 12, 32 of 1283 proteins fulfilled our threshold for being differentially expressed, i.e. their levels were changed by ≥10% with a false discovery rate <1% (empagliflozin vs. placebo). Among these, nine proteins demonstrated the largest treatment effect of empagliflozin: insulin-like growth factor-binding protein 1, transferrin receptor protein 1, carbonic anhydrase 2, erythropoietin, protein-glutamine gamma-glutamyltransferase 2, thymosin beta-10, U-type mitochondrial creatine kinase, insulin-like growth factor-binding protein 4, and adipocyte fatty acid-binding protein 4. The changes of the proteins from baseline to Week 52 were generally concordant with the changes from the baseline to Week 12, except empagliflozin reduced levels of kidney injury molecule-1 by ≥10% at Week 52, but not at Week 12. The most common biological action of differentially expressed proteins appeared to be the promotion of autophagic flux in the heart, kidney or endothelium, a feature of 6 proteins. Other effects of differentially expressed proteins on the heart included the reduction of oxidative stress, inhibition of inflammation and fibrosis, and the enhancement of mitochondrial health and energy, repair, and regenerative capacity. The actions of differentially expressed proteins in the kidney involved promotion of autophagy, integrity and regeneration, suppression of renal inflammation and fibrosis, and modulation of renal tubular sodium reabsorption.
CONCLUSIONS
Changes in circulating protein levels in patients with heart failure are consistent with the findings of experimental studies that have shown that the effects of SGLT2 inhibitors are likely related to actions on the heart and kidney to promote autophagic flux, nutrient deprivation signalling and transmembrane sodium transport.
Topics: Humans; Diabetes Mellitus, Type 2; Heart Failure; Inflammation; Proteomics; Sodium; Sodium-Glucose Transporter 2 Inhibitors; Somatomedins
PubMed: 36017745
DOI: 10.1093/eurheartj/ehac495 -
Current Osteoporosis Reports Aug 2020The purpose of this review is to describe the current state of our thinking regarding bone-muscle interactions beyond the mechanical perspective. (Review)
Review
PURPOSE OF REVIEW
The purpose of this review is to describe the current state of our thinking regarding bone-muscle interactions beyond the mechanical perspective.
RECENT FINDINGS
Recent and prior evidence has begun to dissect many of the molecular mechanisms that bone and muscle use to communicate with each other and to modify each other's function. Several signaling factors produced by muscle and bone have emerged as potential mediators of these biochemical/molecular interactions. These include muscle factors such as myostatin, Irisin, BAIBA, IL-6, and the IGF family and the bone factors FGF-23, Wnt1 and Wnt3a, PGE2, FGF9, RANKL, osteocalcin, and sclerostin. The identification of these signaling molecules and their underlying mechanisms offers the very real and exciting possibility that new pharmaceutical approaches can be developed that will permit the simultaneous treatments of diseases that often occur in combination, such as osteoporosis and sarcopenia.
Topics: Adaptor Proteins, Signal Transducing; Aminoisobutyric Acids; Bone and Bones; Dinoprostone; Fibroblast Growth Factor 9; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Fibronectins; Humans; Interleukin-6; Muscle, Skeletal; Myostatin; Osteocalcin; Paracrine Communication; RANK Ligand; Somatomedins; Wnt1 Protein; Wnt3A Protein
PubMed: 32519283
DOI: 10.1007/s11914-020-00602-6 -
Biomolecules Oct 2022The insulin family consists of insulin, insulin-like growth factor 1 (IGF-1), insulin-like growth factor 2 (IGF-2), their receptors (IR, IGF-1R and IGF-2R), and their... (Review)
Review
The insulin family consists of insulin, insulin-like growth factor 1 (IGF-1), insulin-like growth factor 2 (IGF-2), their receptors (IR, IGF-1R and IGF-2R), and their binding proteins. All three ligands are involved in cell proliferation, apoptosis, protein synthesis and metabolism due to their homologous sequences and structural similarities. Insulin-like growth factor 2, a member of the insulin family, plays an important role in embryonic development, metabolic disorders, and tumorigenesis by combining with three receptors with different degrees of affinity. The main pathological feature of various fibrotic diseases is the excessive deposition of extracellular matrix (ECM) after tissue and organ damage, which eventually results in organic dysfunction because scar formation replaces tissue parenchyma. As a mitogenic factor, IGF-2 is overexpressed in many fibrotic diseases. It can promote the proliferation of fibroblasts significantly, as well as the production of ECM in a time- and dose-dependent manner. This review aims to describe the expression changes and fibrosis-promoting effects of IGF-2 in the skin, oral cavity, heart, lung, liver, and kidney fibrotic tissues.
Topics: Humans; Insulin-Like Growth Factor II; Receptor, Insulin; Fibrosis; Extracellular Matrix; Insulin
PubMed: 36358907
DOI: 10.3390/biom12111557 -
Nature Communications Sep 2022Chronic activation of stress hormones such as glucocorticoids leads to skeletal muscle wasting in mammals. However, the molecular events that mediate...
Chronic activation of stress hormones such as glucocorticoids leads to skeletal muscle wasting in mammals. However, the molecular events that mediate glucocorticoid-induced muscle wasting are not well understood. Here, we show that SIRT6, a chromatin-associated deacetylase indirectly regulates glucocorticoid-induced muscle wasting by modulating IGF/PI3K/AKT signaling. Our results show that SIRT6 levels are increased during glucocorticoid-induced reduction of myotube size and during skeletal muscle atrophy in mice. Notably, overexpression of SIRT6 spontaneously decreases the size of primary myotubes in a cell-autonomous manner. On the other hand, SIRT6 depletion increases the diameter of myotubes and protects them against glucocorticoid-induced reduction in myotube size, which is associated with enhanced protein synthesis and repression of atrogenes. In line with this, we find that muscle-specific SIRT6 deficient mice are resistant to glucocorticoid-induced muscle wasting. Mechanistically, we find that SIRT6 deficiency hyperactivates IGF/PI3K/AKT signaling through c-Jun transcription factor-mediated increase in IGF2 expression. The increased activation, in turn, leads to nuclear exclusion and transcriptional repression of the FoxO transcription factor, a key activator of muscle atrophy. Further, we find that pharmacological inhibition of SIRT6 protects against glucocorticoid-induced muscle wasting in mice by regulating IGF/PI3K/AKT signaling implicating the role of SIRT6 in glucocorticoid-induced muscle atrophy.
Topics: Animals; Chromatin; Glucocorticoids; Mammals; Mice; Muscle Fibers, Skeletal; Muscular Atrophy; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Sirtuins; Somatomedins; Transcription Factors
PubMed: 36109503
DOI: 10.1038/s41467-022-32905-w -
Growth Hormone & IGF Research :... Apr 2019Atherosclerosis is an inflammatory arterial pathogenic condition, which leads to ischemic cardiovascular diseases, such as coronary artery disease and myocardial... (Review)
Review
Atherosclerosis is an inflammatory arterial pathogenic condition, which leads to ischemic cardiovascular diseases, such as coronary artery disease and myocardial infarction, stroke, and peripheral arterial disease. Atherosclerosis is a multifactorial disorder and its pathophysiology is highly complex. Changes in expression of multiple genes coupled with environmental and lifestyle factors initiate cascades of adverse events involving multiple types of cells (e.g. vascular endothelial cells, smooth muscle cells, and macrophages). IGF-1 is a pleiotropic factor, which is found in the circulation (endocrine IGF-1) and is also produced locally in arteries (endothelial cells and smooth muscle cells). IGF-1 exerts a variety of effects on these cell types in the context of the pathogenesis of atherosclerosis. In fact, there is an increasing body of evidence suggesting that IGF-1 has beneficial effects on the biology of atherosclerosis. This review will discuss recent findings relating to clinical investigations on the relation between IGF-1 and cardiovascular disease and basic research using animal models of atherosclerosis that have elucidated some of the mechanisms underlying atheroprotective effects of IGF-1.
Topics: Cardiovascular Diseases; Humans; Insulin-Like Growth Factor I
PubMed: 30735831
DOI: 10.1016/j.ghir.2019.01.002