scholarly journals The GH/IGF1 axis and signaling pathways in the muscle and bone: mechanisms underlying age-related skeletal muscle wasting and osteoporosis

2010 ◽  
Vol 205 (3) ◽  
pp. 201-210 ◽  
Author(s):  
Sebastio Perrini ◽  
Luigi Laviola ◽  
Marcos C Carreira ◽  
Angelo Cignarelli ◽  
Annalisa Natalicchio ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Molecular Mechanisms ◽  
Signs And Symptoms ◽  
Well Being ◽  
Serum Levels ◽  
Normal Range ◽  
Gh Secretion ◽  
Skeletal Muscle Wasting ◽  
Age Related ◽  
Age Dependent

The widespread increase in life expectancy is accompanied by an increased prevalence of features of physical frailty. Signs and symptoms may include sarcopenia and osteopenia, reduced exercise capacity, and diminished sense of well-being. The pathogenesis of age-associated sarcopenia and osteopenia is multifactorial, and hormonal decline may be a contributing factor. Aging is associated with a progressive decrease in GH secretion, and more than 30% of elderly people have circulating IGF1 levels below the normal range found in the young. GH acts directly on target tissues, including skeletal muscle and bone among many others, but many effects are mediated indirectly by circulating (liver-derived) or locally produced IGF1. Aging is also associated with reduced insulin sensitivity which, in turn, may contribute to the impairment of IGF1 action. Recent experimental evidence suggests that besides the age-dependent decline in GH and IGF1 serum levels, the dysregulation of GH and IGF1 actions due to impairment of the post-receptor signaling machinery may contribute to the loss of muscle mass and osteopenia. This article will focus on the molecular mechanisms of impaired GH and IGF1 signaling and action in aging, and their role in the pathogenesis of sarcopenia and osteoporosis.

Cellular and molecular mechanisms underlying age-related skeletal muscle wasting and weakness

2008 ◽  
Vol 9 (4) ◽  
pp. 213-228 ◽  
Author(s):  
James G. Ryall ◽  
Jonathan D. Schertzer ◽  
Gordon S. Lynch
Keyword(s):  
Skeletal Muscle ◽  
Molecular Mechanisms ◽  
Muscle Wasting ◽  
Skeletal Muscle Wasting ◽  
Age Related

scholarly journals Age-dependent Increases in Adrenal Cytochrome b5 and Serum 5-Androstenediol-3-sulfate

2016 ◽  
Vol 101 (12) ◽  
pp. 4585-4593 ◽  
Author(s):  
Juilee Rege ◽  
Shigehiro Karashima ◽  
Antonio M. Lerario ◽  
Joshua M. Smith ◽  
Richard J. Auchus ◽  
...  
Keyword(s):  
Cytochrome B5 ◽  
Serum Levels ◽  
Dehydroepiandrosterone Sulfate ◽  
Zona Fasciculata ◽  
Adrenocortical Cells ◽  
Normal Children ◽  
Age Related ◽  
Age Dependent ◽  
Lyase Activity ◽  
Liquid Chromatography Tandem Mass

Context: Adrenal production of dehydroepiandrosterone sulfate (DHEA-S) increases throughout childhood owing to expansion of the zona reticularis (ZR). ZR features cells with a steroidogenic phenotype distinct from that of the adjacent zona fasciculata, with higher expression of cytochrome b5 type A (CYB5A) and steroid sulfotransferase type 2A1 but decreased 3β-hydroxysteroid dehydrogenase type 2 (HSD3B2). In addition to DHEA-S, three adrenal Δ5-steroid sulfates could provide additional tools to define adrenal maturation. Objective: This study sought to simultaneously measure serum levels of four adrenal Δ5-steroid sulfates, pregnenolone sulfate (Preg-S), 17α-hydroxypregnenolone sulfate (17OHPreg-S), DHEA-S, and 5-androstenediol-3-sulfate (Adiol-S) as a function of age and relate their production to the age-dependent adrenal localization of CYB5A. Participants and Methods: Δ5-steroid sulfates were quantified by liquid chromatography–tandem mass spectrometry in sera from 247 normal children (129 males,118 females) age 1.5–18 y and 42 adults (20 males, 22 females). Immunofluorescence localized HSD3B2 and CYB5A in normal adrenal glands from subjects age 2–35 y. Finally, HAC15 adrenocortical cells were transduced with lentiviral short hairpin RNA to suppress CYB5A expression. Results: Of the Δ5-steroid sulfates quantified, DHEA-S was most abundant. Adiol-S increased in parallel with DHEA-S. Steroid ratios (17OHPreg-S/DHEA-S) suggested increases in 17,20-lyase activity during childhood. Immunofluorescence analysis showed age-related increases in ZR CYB5A immunoreactivity. Furthermore, silencing CYB5A in HAC15 adrenocortical cells significantly reduced DHEA-S and Adiol-S production. Conclusion: Adiol-S shows a similar age-related increase to that of DHEA-S. This likely results from the childhood expansion of CYB5A-expressing ZR, which enhances 17,20-lyase activity and the production of DHEA-S and Adiol-S.

scholarly journals Telomere length and age-dependent telomere attrition: the blood-and-muscle model

2019 ◽  
Vol 97 (4) ◽  
pp. 328-334 ◽  
Author(s):  
Mirna N. Chahine ◽  
Simon Toupance ◽  
Sandy El-Hakim ◽  
Carlos Labat ◽  
Sylvie Gautier ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Telomere Length ◽  
Cross Sectional Study ◽  
Muscle Model ◽  
Atherosclerotic Cardiovascular Disease ◽  
Cross Sectional ◽  
Telomere Attrition ◽  
Age Related ◽  
Age Dependent ◽  
Muscle Biopsies

Short telomere length (TL) is associated with atherosclerotic cardiovascular disease (ACVD) and other age-related diseases. It is unclear whether these associations originate from having inherently short TL or a faster TL attrition before or during disease development. We proposed the blood-and-muscle model to assess TL dynamics throughout life course. Our objective was to measure TL in leukocytes (LTL) and in skeletal muscle (MTL), which served as a proxy of TL at birth. The delta (MTL–LTL) represented life-long telomere attrition. Blood draws and skeletal muscle biopsies were performed on 35 Lebanese individuals undergoing surgery. Following DNA extraction, LTL and MTL were measured by Southern blot. In every individual aged between 30 and 85 years, MTL was longer than LTL. With age, MTL and LTL decreased, but the delta (MTL–LTL) increased by 14 bp/year. We validated the blood-and-muscle model that allowed us to identify TL, TL at birth, and lifelong TL attrition in a cross-sectional study. This model can be used in larger cross-sectional studies to evaluate the association of telomere dynamics with age-related diseases onset and progression.

Strategies to Reduce Age-Related Skeletal Muscle Wasting

2005 ◽  
pp. 63-84 ◽  
Author(s):  
Grodon S. Lynch ◽  
Thea Shavlakadze ◽  
Miranda D. Grounds
Keyword(s):  
Skeletal Muscle ◽  
Muscle Wasting ◽  
Skeletal Muscle Wasting ◽  
Age Related

scholarly journals Thrombospondin-1 in maladaptive aging responses: a concept whose time has come

2020 ◽  
Vol 319 (1) ◽  
pp. C45-C63
Author(s):  
Jeffrey S. Isenberg ◽  
David D. Roberts
Keyword(s):  
Molecular Mechanisms ◽  
Synapse Formation ◽  
Genotoxic Stress ◽  
Cell Types ◽  
Cellular Tissue ◽  
Therapeutic Agents ◽  
Age Related ◽  
Organ Systems ◽  
Age Dependent ◽  
Thrombospondin 1

Numerous age-dependent alterations at the molecular, cellular, tissue and organ systems levels underlie the pathophysiology of aging. Herein, the focus is upon the secreted protein thrombospondin-1 (TSP1) as a promoter of aging and age-related diseases. TSP1 has several physiological functions in youth, including promoting neural synapse formation, mediating responses to ischemic and genotoxic stress, minimizing hemorrhage, limiting angiogenesis, and supporting wound healing. These acute functions of TSP1 generally require only transient expression of the protein. However, accumulating basic and clinical data reinforce the view that chronic diseases of aging are associated with accumulation of TSP1 in the extracellular matrix, which is a significant maladaptive contributor to the aging process. Identification of the relevant cell types that chronically produce and respond to TSP1 and the molecular mechanisms that mediate the resulting maladaptive responses could direct the development of therapeutic agents to delay or revert age-associated maladies.

scholarly journals miR-155 Predicts Long-Term Mortality in Critically Ill Patients Younger than 65 Years

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Frank Tacke ◽  
Martina E. Spehlmann ◽  
Mihael Vucur ◽  
Fabian Benz ◽  
Mark Luedde ◽  
...  
Keyword(s):  
Critical Illness ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Prognostic Biomarker ◽  
Serum Levels ◽  
Disease Etiology ◽  
Age Related ◽  
Age Dependent ◽  
Similar Accuracy

Introduction. Alterations in miR-155 serum levels have been described in inflammatory and infectious diseases. Moreover, a role for miR-155 in aging and age-related diseases was recently suggested. We therefore analyzed a potential age-dependent prognostic value of circulating miR-155 as a serum-based marker in critical illness. Methods. Concentrations of circulating miR-155 were determined in 218 critically ill patients and 76 healthy controls. Results. By using qPCR, we demonstrate that miR-155 serum levels are elevated in patients with critical illness when compared to controls. Notably, levels of circulating miR-155 were independent on the severity of disease, the disease etiology, or the presence of sepsis. In the total cohort, miR-155 was not an indicator for patient survival. Intriguingly, when patients were subdivided according to their age upon admission to the ICU into those younger than 65 years, lower levels of miR-155 turned out as a strong marker, indicating patient mortality with a similar accuracy than other markers frequently used to evaluate critically ill patients on a medical ICU. Conclusion. In summary, the data provided within this study suggest an age-specific role of miR-155 as a prognostic biomarker in patients younger than 65 years. Our study is the first to describe an age-dependent miRNA-based prognostic biomarker in human diseases.

scholarly journals FTIR Spectroscopy as a Tool to Study Age-Related Changes in Cardiac and Skeletal Muscle of Female C57BL/6J Mice

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6410
Author(s):  
Sandra Magalhães ◽  
Idália Almeida ◽  
Filipa Martins ◽  
Fátima Camões ◽  
Ana R. Soares ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Ftir Spectroscopy ◽  
Conformational Changes ◽  
Molecular Mechanisms ◽  
Protein Secondary Structure ◽  
Multivariate Statistical ◽  
Age Related ◽  
Muscle Tissues ◽  
Aging Studies ◽  
Old Mice

Studying aging is important to further understand the molecular mechanisms underlying this physiological process and, ideally, to identify a panel of aging biomarkers. Animals, in particular mice, are often used in aging studies, since they mimic important features of human aging, age quickly, and are easy to manipulate. The present work describes the use of Fourier Transform Infrared (FTIR) spectroscopy to identify an age-related spectroscopic profile of the cardiac and skeletal muscle tissues of C57BL/6J female mice. We acquired ATR-FTIR spectra of cardiac and skeletal muscle at four different ages: 6; 12; 17 and 24 months (10 samples at each age) and analyzed the data using multivariate statistical tools (PCA and PLS) and peak intensity analyses. The results suggest deep changes in protein secondary structure in 24-month-old mice compared to both tissues in 6-month-old mice. Oligomeric structures decreased with age in both tissues, while intermolecular β-sheet structures increased with aging in cardiac muscle but not in skeletal muscle. Despite FTIR spectroscopy being unable to identify the proteins responsible for these conformational changes, this study gives insights into the potential of FTIR to monitor the aging process and identify an age-specific spectroscopic signature.

scholarly journals cAMP signaling in skeletal muscle adaptation: hypertrophy, metabolism, and regeneration

2012 ◽  
Vol 303 (1) ◽  
pp. E1-E17 ◽  
Author(s):  
Rebecca Berdeaux ◽  
Randi Stewart
Keyword(s):  
Skeletal Muscle ◽  
Muscular Dystrophy ◽  
Molecular Mechanisms ◽  
Muscle Development ◽  
Camp Signaling ◽  
Metabolic Phenotype ◽  
Muscle Adaptation ◽  
Age Related ◽  
Organ Systems

Among organ systems, skeletal muscle is perhaps the most structurally specialized. The remarkable subcellular architecture of this tissue allows it to empower movement with instructions from motor neurons. Despite this high degree of specialization, skeletal muscle also has intrinsic signaling mechanisms that allow adaptation to long-term changes in demand and regeneration after acute damage. The second messenger adenosine 3′,5′-monophosphate (cAMP) not only elicits acute changes within myofibers during exercise but also contributes to myofiber size and metabolic phenotype in the long term. Strikingly, sustained activation of cAMP signaling leads to pronounced hypertrophic responses in skeletal myofibers through largely elusive molecular mechanisms. These pathways can promote hypertrophy and combat atrophy in animal models of disorders including muscular dystrophy, age-related atrophy, denervation injury, disuse atrophy, cancer cachexia, and sepsis. cAMP also participates in muscle development and regeneration mediated by muscle precursor cells; thus, downstream signaling pathways may potentially be harnessed to promote muscle regeneration in patients with acute damage or muscular dystrophy. In this review, we summarize studies implicating cAMP signaling in skeletal muscle adaptation. We also highlight ligands that induce cAMP signaling and downstream effectors that are promising pharmacological targets.

scholarly journals MECHANISMS OF BRAIN REJUVENATION

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S587-S587
Author(s):  
Saul Villeda
Keyword(s):  
Molecular Mechanisms ◽  
Aging Brain ◽  
Aging Effects ◽  
Effective Strategies ◽  
Mechanistic Insight ◽  
Age Related ◽  
Age Dependent ◽  
Cognitive Faculties ◽  
Insight Into ◽  
Aging Factors

Abstract A growing body of work has shown that systemic manipulations, such as heterochronic parabiosis and young blood administration, can partially reverse age-related cellular impairments and loss of cognitive faculties in the aged brain. These studies have revealed an age-dependent bi-directionality in the influence of the systemic environment indicating anti-aging factors in young blood elicit rejuvenation while pro-aging factors in old blood drive aging. It has been proposed that introducing anti-aging factors or mitigating the effect of pro-aging factors may provide effective strategies to rejuvenate aging phenotypes. Despite this potential, much is unknown as to the systemic and molecular mechanisms regulating anti-aging and pro-aging effects of blood-borne factors. I will discuss work from my research group that begins to provide mechanistic insight into the systemic and molecular drivers promoting rejuvenation in the aging brain.

scholarly journals Molecular Mechanisms Underlying the Beneficial Effects of Exercise on Brain Function and Neurological Disorders

2021 ◽  
Vol 22 (8) ◽  
pp. 4052
Author(s):  
Kévin Nay ◽  
William J. Smiles ◽  
Jacqueline Kaiser ◽  
Luke M. McAloon ◽  
Kim Loh ◽  
...  
Keyword(s):  
Brain Function ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Well Being ◽  
Developed Countries ◽  
Beneficial Effects ◽  
Therapeutic Benefits ◽  
Age Related ◽  
Underlying Mechanisms ◽  
The Impact

As life expectancy has increased, particularly in developed countries, due to medical advances and increased prosperity, age-related neurological diseases and mental health disorders have become more prevalent health issues, reducing the well-being and quality of life of sufferers and their families. In recent decades, due to reduced work-related levels of physical activity, and key research insights, prescribing adequate exercise has become an innovative strategy to prevent or delay the onset of these pathologies and has been demonstrated to have therapeutic benefits when used as a sole or combination treatment. Recent evidence suggests that the beneficial effects of exercise on the brain are related to several underlying mechanisms related to muscle–brain, liver–brain and gut–brain crosstalk. Therefore, this review aims to summarize the most relevant current knowledge of the impact of exercise on mood disorders and neurodegenerative diseases, and to highlight the established and potential underlying mechanisms involved in exercise–brain communication and their benefits for physiology and brain function.

Sign in / Sign up

Export Citation Format

Share Document