scholarly journals Manifestations of Age on Autophagy, Mitophagy and Lysosomes in Skeletal Muscle

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1054
Author(s):  
Matthew Triolo ◽  
David A. Hood
Keyword(s):  
Molecular Complexes ◽  
Age Related ◽  
Degradative Enzymes ◽  
Autophagy Pathway ◽  
Aging Muscle ◽  
Novel Therapeutic Strategies ◽  
End Stage ◽  
And Function ◽  
Species Production

Sarcopenia is the loss of both muscle mass and function with age. Although the molecular underpinnings of sarcopenia are not fully understood, numerous pathways are implicated, including autophagy, in which defective cargo is selectively identified and degraded at the lysosome. The specific tagging and degradation of mitochondria is termed mitophagy, a process important for the maintenance of an organelle pool that functions efficiently in energy production and with relatively low reactive oxygen species production. Emerging data, yet insufficient, have implicated various steps in this pathway as potential contributors to the aging muscle atrophy phenotype. Included in this is the lysosome, the end-stage organelle possessing a host of proteolytic and degradative enzymes, and a function devoted to the hydrolysis and breakdown of defective molecular complexes and organelles. This review provides a summary of our current understanding of how the autophagy-lysosome system is regulated in aging muscle, highlighting specific areas where knowledge gaps exist. Characterization of the autophagy pathway with a particular focus on the lysosome will undoubtedly pave the way for the development of novel therapeutic strategies to combat age-related muscle loss.

CURRENT NUTRITIONAL RECOMMENDATIONS AND NOVEL DIETARY STRATEGIES TO MANAGE SARCOPENIA

2013 ◽  
pp. 1-16
Author(s):  
R. CALVANI ◽  
A. MICCHELI ◽  
F. LANDI ◽  
M. BOSSOLA ◽  
M. CESARI ◽  
...  
Keyword(s):  
Physical Exercise ◽  
Independent Living ◽  
Optimal Timing ◽  
Nutritional Interventions ◽  
Adverse Health Outcomes ◽  
Age Related ◽  
Aging Muscle ◽  
And Function ◽  
Dietary Agents ◽  
Dietary Strategies

Sarcopenia, the loss of skeletal muscle mass and function that occurs with aging, is associated withincreased risk for several adverse health outcomes, including frailty, disability, falls, loss of independent living,and mortality. At present, no pharmacological treatment exists that is able to definitely halt the progression ofsarcopenia. Likewise, no pharmacological remedies are yet available to prevent the onset of age-related musclewasting. The combination of nutritional interventions and physical exercise appears to be the most effectivestrategy presently available for the management of sarcopenia. The purposes of this review are to summarize thecurrent knowledge on the role of nutrition as a countermeasure for sarcopenia, illustrate the mechanisms of actionof relevant dietary agents on the aging muscle, and introduce novel nutritional strategies that may help preservemuscle mass and function into old age. Issues related to the identification of the optimal timing of nutritionalinterventions in the context of primary and secondary prevention are also discussed. Finally, the prospect ofelaborating personalized dietary and physical exercise recommendations through the implementation ofintegrated, high-throughput analytic approaches is illustrated.

scholarly journals Characterization of Mitochondrial GSH Transporters and Their Role in RPE Protection

2018 ◽  
Author(s):  
Mo Wang ◽  
Ling-ing Lau ◽  
Parameswaran G. Sreekumar ◽  
Christine Spee ◽  
Lin Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Retinal Pigment ◽  
Retinal Pigment Epithelial Cells ◽  
Age Related Macular Degeneration ◽  
Ocular Tissues ◽  
Age Related ◽  
And Function ◽  
And Oxidative Stress ◽  
Pigment Epithelial Cells

Mitochondrial dysfunction and oxidative stress are thought to be relevant to the pathogenesis of age-related macular degeneration (AMD). Glutathione (GSH) homeostasis fulfills a number of important roles in mitochondria, such as maintenance of mitochondrial DNA and respiratory competency of cells. Although the transport of mitochondrial GSH (mGSH) is not fully understood, increasing evidence from non-ocular tissues suggests that OGC (2-oxoglutarate carrier, SLC25A11) and DIC (dicarboxylate carrier, SLC25A10) are involved in mGSH transport. However, whether OGC and DIC mediate the transfer of GSH into the mitochondria of retinal pigment epithelial cells (RPE) remains unknown. Thus, we investigated the expression, localization, and function of OGC and DIC in human RPE (hRPE) in relation to oxidative stress and GSH. Both OGC and DIC are expressed in hRPE and are localized in mitochondria. We also found a dose and time-dependent decrease of OGC and DIC expression under oxidative stress and increased expression in polarized RPE. Our data show that the downregulation of OGC and DIC resulted in increased apoptosis and mGSH depletion which can be overcome by co-treatment with GSH-MEE. These findings suggest that overexpression of OGC and DIC may be an effective strategy to decrease susceptibility to mitochondrial toxicants by elevation of mGSH.

Renal and urological disease

2019 ◽  
pp. 824-842
Author(s):  
Christopher W. Ide ◽  
Edwina A. Brown
Keyword(s):  
Renal Failure ◽  
End Stage Renal Disease ◽  
Well Being ◽  
Health Team ◽  
Age Related ◽  
The Uk ◽  
Stage Renal Disease ◽  
End Stage ◽  
And Function ◽  
Therapy Treatment

Diabetes and age-related changes are now the commonest cause of end-stage renal disease (ESRD) in the UK. Polycystic kidney disease is the commonest inherited disorder leading to renal failure. Chronic renal failure implies permanent renal damage, which is likely to be progressive and will eventually require renal replacement therapy. Treatment of ESRD using haemodialysis and peritoneal dialysis can significantly improve physical and metabolic well-being and function but the proportion of those who continue to work with ESRD remains very low despite advances in treatment. Kidney transplantation enables many patients to return to normal lives including work. Reintegration of patients into the workforce following transplantation or dialysis offers an exciting and rewarding challenge to the wider health team.

scholarly journals Skeletal muscle mitochondrial respiration in a model of age-related osteoarthritis is impaired after dietary rapamycin

2021 ◽  
Author(s):  
Christian J Elliehausen ◽  
Dennis M Minton ◽  
Alexander D Nichol ◽  
Adam R Konopka
Keyword(s):  
Skeletal Muscle ◽  
Mitochondrial Function ◽  
Mitochondrial Respiration ◽  
Guinea Pigs ◽  
Muscle Size ◽  
Skeletal Muscle Mitochondria ◽  
Age Related ◽  
End Stage ◽  
And Function ◽  
Permeabilized Muscle

A decline in skeletal muscle mitochondrial function is associated with the loss of skeletal muscle size and function during knee osteoarthritis (OA). We have recently reported that the 12-weeks of dietary rapamycin (Rap, 14ppm), with or without metformin (Met, 1000ppm), increased plasma glucose and OA severity in male Dunkin Hartley (DH) guinea pigs, a model of naturally occurring, age-related OA. The purpose of the current study was to determine if increased OA severity after dietary Rap and Rap+Met was accompanied by impaired skeletal muscle mitochondrial function. Mitochondrial respiration and hydrogen peroxide (H2O2) emissions were evaluated in permeabilized muscle fibers via high-resolution respirometry and fluorometry using either a saturating bolus or titration of ADP. Rap and Rap+Met decreased complex I (CI)-linked respiration and increased ADP sensitivity, consistent with previous findings in patients with end-stage OA. Rap also tended to decrease mitochondrial H2O2 emissions, however, this was no longer apparent after normalizing to respiration. The decrease in CI-linked respiration was accompanied with lower CI protein abundance. This is the first inquiry into how lifespan extending treatments Rap and Rap+Met can influence skeletal muscle mitochondria in a model of age-related OA. Collectively, our data suggest that Rap with or without Met inhibits CI-linked capacity and increases ADP sensitivity in DH guinea pigs that have greater OA severity.

Functional characterization of human brown adipose tissue metabolism

2020 ◽  
Vol 477 (7) ◽  
pp. 1261-1286 ◽  
Author(s):  
Marie Anne Richard ◽  
Hannah Pallubinsky ◽  
Denis P. Blondin
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Functional Characterization ◽  
Human Infants ◽  
Positron Emission ◽  
Brown Adipose ◽  
Treatment Of Obesity ◽  
And Function

Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.

Parasite defense mechanisms in bees: behavior, immunity, antimicrobials, and symbionts

2019 ◽  
Vol 4 (1) ◽  
pp. 59-76 ◽  
Author(s):  
Alison E. Fowler ◽  
Rebecca E. Irwin ◽  
Lynn S. Adler
Keyword(s):  
Defense Mechanisms ◽  
Poor Quality ◽  
Future Research ◽  
Immune Priming ◽  
Social Bees ◽  
Bee Health ◽  
Landscape Scales ◽  
And Function ◽  
Solitary Species

Parasites are linked to the decline of some bee populations; thus, understanding defense mechanisms has important implications for bee health. Recent advances have improved our understanding of factors mediating bee health ranging from molecular to landscape scales, but often as disparate literatures. Here, we bring together these fields and summarize our current understanding of bee defense mechanisms including immunity, immunization, and transgenerational immune priming in social and solitary species. Additionally, the characterization of microbial diversity and function in some bee taxa has shed light on the importance of microbes for bee health, but we lack information that links microbial communities to parasite infection in most bee species. Studies are beginning to identify how bee defense mechanisms are affected by stressors such as poor-quality diets and pesticides, but further research on this topic is needed. We discuss how integrating research on host traits, microbial partners, and nutrition, as well as improving our knowledge base on wild and semi-social bees, will help inform future research, conservation efforts, and management.

Gaunilo Parodies Anselm

2014 ◽  
Vol 17 (1) ◽  
pp. 45-71
Author(s):  
Geo Siegwart
Keyword(s):  
Detailed Comparison ◽  
The Third ◽  
Common Structure ◽  
Logical Reconstruction ◽  
Points Of View ◽  
And Function

The main objective is an interpretation of the island parody, in particular a logical reconstruction of the parodying argument that stays close to the text. The parodied reasoning is identified as the proof in the second chapter of the Proslogion, more specifically, this proof as it is represented by Gaunilo in the first chapter of his Liber pro insipiente. The second task is a detailed comparison between parodied and parodying argument as well as an account of their common structure. The third objective is a tentative characterization of the nature and function of parodies of arguments. It seems that parodying does not add new pertinent points of view to the usual criticism of an argument.

Preparation and Characterization of β-glucosidase Films for Stabilization and Handling in Dry Configurations

2020 ◽  
Vol 21 (8) ◽  
pp. 741-747
Author(s):  
Liguang Zhang ◽  
Yanan Shen ◽  
Wenjing Lu ◽  
Lengqiu Guo ◽  
Min Xiang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Protein Function ◽  
Protein Stabilization ◽  
Functional Protein ◽  
Elongation At Break ◽  
Gelatin Films ◽  
The Stability ◽  
And Function ◽  
General Method

Background: Although the stability of proteins is of significance to maintain protein function for therapeutical applications, this remains a challenge. Herein, a general method of preserving protein stability and function was developed using gelatin films. Method: Enzymes immobilized onto films composed of gelatin and Ethylene Glycol (EG) were developed to study their ability to stabilize proteins. As a model functional protein, β-glucosidase was selected. The tensile properties, microstructure, and crystallization behavior of the gelatin films were assessed. Result: Our results indicated that film configurations can preserve the activity of β-glucosidase under rigorous conditions (75% relative humidity and 37°C for 47 days). In both control films and films containing 1.8 % β-glucosidase, tensile strength increased with increased EG content, whilst the elongation at break increased initially, then decreased over time. The presence of β-glucosidase had a negligible influence on tensile strength and elongation at break. Scanning electron-microscopy (SEM) revealed that with increasing EG content or decreasing enzyme concentrations, a denser microstructure was observed. Conclusion: In conclusion, the dry film is a promising candidate to maintain protein stabilization and handling. The configuration is convenient and cheap, and thus applicable to protein storage and transportation processes in the future.

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