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Chen Y, Wu J. Aging-Related Sarcopenia: Metabolic Characteristics and Therapeutic Strategies. Aging Dis 2024:AD.2024.0407. [PMID: 38739945 DOI: 10.14336/ad.2024.0407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 04/07/2024] [Indexed: 05/16/2024] Open
Abstract
The proportion of the elderly population is gradually increasing as a result of medical care advances, leading to a subsequent surge in geriatric diseases that significantly impact quality of life and pose a substantial healthcare burden. Sarcopenia, characterized by age-related decline in skeletal muscle mass and quality, affects a considerable portion of older adults, particularly the elderly, and can result in adverse outcomes such as frailty, fractures, bedridden, hospitalization, and even mortality. Skeletal muscle aging is accompanied by underlying metabolic changes. Therefore, elucidating these metabolic profiles and specific mechanisms holds promise for informing prevention and treatment strategies for sarcopenia. This review provides a comprehensive overview of the key metabolites identified in current clinical studies on sarcopenia and their potential pathophysiological alterations in metabolic activity. Besides, we examine potential therapeutic strategies for sarcopenia from a perspective focused on metabolic regulation.
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Miller SG, Hafen PS, Law AS, Springer CB, Logsdon DL, O'Connell TM, Witczak CA, Brault JJ. AMP deamination is sufficient to replicate an atrophy-like metabolic phenotype in skeletal muscle. Metabolism 2021; 123:154864. [PMID: 34400216 PMCID: PMC8453098 DOI: 10.1016/j.metabol.2021.154864] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/22/2021] [Accepted: 08/10/2021] [Indexed: 02/01/2023]
Abstract
BACKGROUND Skeletal muscle atrophy, whether caused by chronic disease, acute critical illness, disuse or aging, is characterized by tissue-specific decrease in oxidative capacity and broad alterations in metabolism that contribute to functional decline. However, the underlying mechanisms responsible for these metabolic changes are largely unknown. One of the most highly upregulated genes in atrophic muscle is AMP deaminase 3 (AMPD3: AMP → IMP + NH3), which controls the content of intracellular adenine nucleotides (AdN; ATP + ADP + AMP). Given the central role of AdN in signaling mitochondrial gene expression and directly regulating metabolism, we hypothesized that overexpressing AMPD3 in muscle cells would be sufficient to alter their metabolic phenotype similar to that of atrophic muscle. METHODS AMPD3 and GFP (control) were overexpressed in mouse tibialis anterior (TA) muscles via plasmid electroporation and in C2C12 myotubes using adenovirus vectors. TA muscles were excised one week later, and AdN were quantified by UPLC. In myotubes, targeted measures of AdN, AMPK/PGC-1α/mitochondrial protein synthesis rates, unbiased metabolomics, and transcriptomics by RNA sequencing were measured after 24 h of AMPD3 overexpression. Media metabolites were measured as an indicator of net metabolic flux. At 48 h, the AMPK/PGC-1α/mitochondrial protein synthesis rates, and myotube respiratory function/capacity were measured. RESULTS TA muscles overexpressing AMPD3 had significantly less ATP than contralateral controls (-25%). In myotubes, increasing AMPD3 expression for 24 h was sufficient to significantly decrease ATP concentrations (-16%), increase IMP, and increase efflux of IMP catabolites into the culture media, without decreasing the ATP/ADP or ATP/AMP ratios. When myotubes were treated with dinitrophenol (mitochondrial uncoupler), AMPD3 overexpression blunted decreases in ATP/ADP and ATP/AMP ratios but exacerbated AdN degradation. As such, pAMPK/AMPK, pACC/ACC, and phosphorylation of AMPK substrates, were unchanged by AMPD3 at this timepoint. AMPD3 significantly altered 191 out of 639 detected intracellular metabolites, but only 30 transcripts, none of which encoded metabolic enzymes. The most altered metabolites were those within purine nucleotide, BCAA, glycolysis, and ceramide metabolic pathways. After 48 h, AMPD3 overexpression significantly reduced pAMPK/AMPK (-24%), phosphorylation of AMPK substrates (-14%), and PGC-1α protein (-22%). Moreover, AMPD3 significantly reduced myotube mitochondrial protein synthesis rates (-55%), basal ATP synthase-dependent (-13%), and maximal uncoupled oxygen consumption (-15%). CONCLUSIONS Increased expression of AMPD3 significantly decreased mitochondrial protein synthesis rates and broadly altered cellular metabolites in a manner similar to that of atrophic muscle. Importantly, the changes in metabolites occurred prior to reductions in AMPK signaling, gene expression, and mitochondrial protein synthesis, suggesting metabolism is not dependent on reductions in oxidative capacity, but may be consequence of increased AMP deamination. Therefore, AMP deamination in skeletal muscle may be a mechanism that alters the metabolic phenotype of skeletal muscle during atrophy and could be a target to improve muscle function during muscle wasting.
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Affiliation(s)
- Spencer G Miller
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA
| | - Paul S Hafen
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Andrew S Law
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | | | - David L Logsdon
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Otolaryngology-Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Thomas M O'Connell
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Otolaryngology-Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Carol A Witczak
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jeffrey J Brault
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, USA.
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Lo CJ, Ko YS, Chang SW, Tang HY, Huang CY, Huang YC, Ho HY, Lin CM, Cheng ML. Metabolic signatures of muscle mass loss in an elderly Taiwanese population. Aging (Albany NY) 2020; 13:944-956. [PMID: 33410783 PMCID: PMC7834982 DOI: 10.18632/aging.202209] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 10/05/2020] [Indexed: 12/25/2022]
Abstract
To identify the association between metabolites and muscle mass in 305 elderly Taiwanese subjects, we conducted a multivariate analysis of 153 plasma samples. Based on appendicular skeletal muscle mass index (ASMI) quartiles, female and male participants were divided into four groups. Quartile 4 (Men: 5.67±0.35, Women: 4.70±0.32 Kg/m2) and quartile 1 (Men: 7.60±0.29, Women: 6.56±0.53 Kg/m2) represented low muscle mass and control groups, respectively. After multivariable adjustment, except for physical function, we found that blood urea nitrogen, creatinine, and age were associated with ASMI in men. However, only triglyceride level was related to ASMI in women. The multiple logistic regression models were used to analyze in each baseline characteristic and metabolite concentration. After the adjustment, we identify amino acid-related metabolites and show that glutamate levels in women and alpha-aminoadipate, Dopa, and citrulline/ornithine levels in men are gender-specific metabolic signatures of muscle mass loss.
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Affiliation(s)
- Chi-Jen Lo
- Metabolomics Core Laboratory, Healthy Aging Research Center, Chang Gung University, Taoyuan 333, Taiwan
| | - Yu-Shien Ko
- Division of Cardiology, Chang Gung Memorial Hospital, Taipei 105, Taiwan.,College of Medicine, Chang Gung University, Taoyuan 333, Taiwan
| | - Su-Wei Chang
- Clinical Informatics and Medical Statistics Research Center, Chang Gung University, Taoyuan 333, Taiwan
| | - Hsiang-Yu Tang
- Metabolomics Core Laboratory, Healthy Aging Research Center, Chang Gung University, Taoyuan 333, Taiwan
| | - Cheng-Yu Huang
- Metabolomics Core Laboratory, Healthy Aging Research Center, Chang Gung University, Taoyuan 333, Taiwan
| | - Yu-Chen Huang
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan.,Department of Thoracic Medicine, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
| | - Hung-Yao Ho
- Metabolomics Core Laboratory, Healthy Aging Research Center, Chang Gung University, Taoyuan 333, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan.,Clinical Metabolomics Core Laboratory, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
| | - Chih-Ming Lin
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan.,Division of Internal Medicine, Chang Gung Memorial Hospital, Taipei 105, Taiwan.,Department of Health Management, Chang Gung Health and Culture Village, Taoyuan 333, Taiwan
| | - Mei-Ling Cheng
- Metabolomics Core Laboratory, Healthy Aging Research Center, Chang Gung University, Taoyuan 333, Taiwan.,Clinical Metabolomics Core Laboratory, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan.,Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan
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Effects of Huang-Lian-Jie-Du Decoction on Oxidative Stress and AMPK-SIRT1 Pathway in Alzheimer's Disease Rat. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2020; 2020:6212907. [PMID: 31976005 PMCID: PMC6959142 DOI: 10.1155/2020/6212907] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 10/08/2019] [Accepted: 10/15/2019] [Indexed: 12/13/2022]
Abstract
Huang-Lian-Jie-Du Decoction (HLJDD), traditional Chinese medicine (TCM), is proven to have ameliorative effects on learning and memory deficits of Alzheimer's disease (AD). The current study aims to reveal the underlying mechanism of HLJDD in the treatment of AD by simultaneous determination on the regulation of HLJDD on oxidative stress, neurotransmitters, and AMPK-SIRT1 pathway in AD. AD model rat was successfully established by injection of D-galactose and Aβ25-35-ibotenic acid. Morris Water Maze (MWM) test was used to evaluate the success of AD modelling. On this basis, an advanced technique with UPLC-QqQ MS/MS was built up and applied to determine the levels of 8 neurotransmitters in rat plasma. Significant alternation in methionine, glutamine, and tryptophan was observed in AD rats' plasma after the administration of HLJDD, relative to the model group. Meanwhile, HLJDD could upregulate the levels of SOD, GSH-Px, AMPK, and SIRT1 and downregulate the content of MDA in the peripheral system of the AD rats. The underlying therapeutic mechanism of HLJDD for the treatment of AD was associated with alleviating oxidation stress, inflammation, neurotransmitters, and energy metabolism. These data provide solid foundation for the potential use of HLJDD to treat AD.
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de Oliveira DC, da Silva Lima F, Sartori T, Santos ACA, Rogero MM, Fock RA. Glutamine metabolism and its effects on immune response: molecular mechanism and gene expression. ACTA ACUST UNITED AC 2016. [DOI: 10.1186/s41110-016-0016-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Abstract
Glutamine, reviewed extensively in the last century, is a key substrate for the splanchnic bed in the whole body and is a nutrient of particular interest in gastrointestinal research. A marked decrease in the plasma glutamine concentration has recently been observed in neonates and adults during acute illness and stress. Although some studies in newborns have shown parenteral and enteral supplementation with glutamine to be of benefit (by decreasing proteolysis and activating the immune system), clinical trials have not demonstrated prolonged advantages such as reductions in mortality or risk of infections in adults. In addition, glutamine is not able to combat the muscle wasting associated with disease or age-related sarcopenia. Oral glutamine supplementation initiated before advanced age in rats increases gut mass and improves the villus height of mucosa, thereby preventing the gut atrophy encountered in advanced age. Enterocytes from very old rats continuously metabolize glutamine into citrulline, which allowed, for the first time, the use of citrulline as a noninvasive marker of intestinal atrophy induced by advanced age.
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Affiliation(s)
- Dominique Meynial-Denis
- D. Meynial-Denis is with the Unit of Human Nutrition (UNH), French National Institute for Agricultural Research (INRA), Joint Research Unit (UMR) 1019, Center for Research in Human Nutrition (CRNH) Auvergne, Clermont-Ferrand, France.
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Beaufrère AM, Neveux N, Patureau Mirand P, Buffière C, Marceau G, Sapin V, Cynober L, Meydinal-Denis D. Long-term intermittent glutamine supplementation repairs intestinal damage (structure and functional mass) with advanced age: assessment with plasma citrulline in a rodent model. J Nutr Health Aging 2014; 18:814-9. [PMID: 25389959 DOI: 10.1007/s12603-014-0554-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Glutamine is the preferred fuel for the rat small intestine and promotes the growth of intestinal mucosa, especially in the event of gut injury. Quantitatively, glutamine is one important precursor for intestinal citrulline release. The aim of this study was to determine whether the effect of glutamine on the increase in intestinal villus height is correlated with an increase in both gut mass and citrulline plasma level in very old rats. METHODS We intermittently supplemented very old (27-mo) female rats with oral glutamine (20% of diet protein). Intestinal histomorphometric analysis of the small bowel was performed. Amino acids, in particular citrulline, were measured in the plasma, liver and jejunum. Markers of renal (creatinine, urea) and liver (alanine aminotransferase [ALT]) and aspartate aminotransferase (AST) functions were measured to evaluate renal and liver functions in relation to aging and to glutamine supplementation. Liver glutathione was also determined to evaluate cellular redox state. RESULTS Glutamine supplementation maintains the body weight of very old rats, not by limiting sarcopenia but rather by increasing the organ mass of the splanchnic area. Total intestine mass was significantly higher in glutamine-supplemented rats than in controls (15%). Measurement of villus height and crypt depth demonstrated that the difference between villus and crypt was significantly improved in glutamine pre-treated rats compared to controls (~ 11%). Plasma citrulline also increased by 15% in glutamine-supplemented rats compared to controls. CONCLUSION Citrulline appears as a biomarker of enterocyte mass in villous atrophy associated with advanced age. Non-invasive measurement of this metabolite may be useful in following the state of the gastrointestinal tract in very old people, whose numbers are increasing worldwide and the care of whom is a major public health issue. The gut may contribute to the malnutrition caused by malabsorption frequently observed in the elderly.
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Affiliation(s)
- A M Beaufrère
- Dominique Meynial-Denis (PhD), Human Nutrition Unit, INRA and Human Nutrition Research Center, Theix 63122 - St Genes Champanelle, France. Phone: +33 (0)4 73 62 43 13; Fax: +33 (0)4 73 62 47 55; E-mail address:
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Meynial-Denis D, Beaufrère AM, Mignon M, Patureau Mirand P. Effect of intermittent glutamine supplementation on skeletal muscle is not long-lasting in very old rats. J Nutr Health Aging 2013; 17:876-9. [PMID: 24257571 DOI: 10.1007/s12603-013-0353-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND AND OBJECTIVE Muscle is the major site for glutamine synthesis via glutamine synthetase (GS). This enzyme is increased 1.5-2 fold in 25-27-mo rats and may be a consequence of aging-induced stress. This stimulation is similar to the induction observed following a catabolic state such as glucocorticoid treatment (6 to 24 months). Although oral glutamine supply regulates the plasma glutamine level, nothing is known if this supplementation is interrupted before the experiment. DESIGN Adult (8-mo) and very old (27-mo) female rats were exposed to intermittent glutamine supplementation for 50 % of their age lifetime. Treated rats received glutamine added to their drinking water and control rats water alone but the effect of glutamine supplementation was only studied 15 days after the last supplementation. RESULTS Glutamine pretreatment discontinued 15 days before the experiment increased plasma glutamine to ~ 0.6 mM, a normal value in very old rats. However, it failed to decrease the up-regulated GS activity in skeletal muscle from very old rats. CONCLUSION Our results suggest that long-term treatment with glutamine started before advanced age but discontinued 15 days before rat sacrifice is effective in increasing plasma glutamine to recover basal adult value and in maintaining plasma glutamine in very old rats, but has no long-lasting effect on the GS activity of skeletal muscle with advanced age.
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Affiliation(s)
- D Meynial-Denis
- Dominique Meynial-Denis (PhD), Human Nutrition Unit, INRA and Human Nutrition Research Center, Theix 63122 - St Genes Champanelle, France. Phone: +33 (0)4 73 62 43 13; Fax: +33 (0)4 73 62 47 55; E-mail address:
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Mayot G, Vidal K, Migné C, Breuillé D, Blum S, Obled C, Papet I. Presence of age-associated low-grade inflammation does not worsen the body response to bacterial infection in old male rats. Biogerontology 2010; 12:133-45. [PMID: 20924673 DOI: 10.1007/s10522-010-9302-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 09/21/2010] [Indexed: 11/24/2022]
Abstract
In the field of frailty, there is an underlying hypothesis that chronic low-grade inflammation contributes to bad outcomes in response to a stressor. The host response to an Escherichia coli infection was assessed in 24 month old male rats exhibiting a chronic low-grade inflammation and in non-inflamed control rats. Mortality, weight loss and sarcopenia were the main outcomes measured. The presence of chronic low-grade inflammation did not affect post-infection mortality, body weight loss and tissue mass decreases. Infection-induced modifications of plasma acute phase proteins concentrations were not higher in low-grade inflamed than non-inflamed rats. Absolute synthesis rates of tissue proteins were independent of the initial inflammatory status, except for liver 10 days after infection. Altogether, age-associated chronic low-grade inflammation in male rats did not worsen the body response to bacterial infection. These results suggest that chronic low-grade inflammation is not an aggravating factor of the spiraling process leading to frailty.
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Affiliation(s)
- Gilles Mayot
- Unité de Nutrition Humaine, INRA, Centre Clermont-Ferrand-Theix, UMR Nutrition Humaine, Saint-Genès-Champanelle, France
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Cruzat VF, Petry ÉR, Tirapegui J. Glutamina: aspectos bioquímicos, metabólicos, moleculares e suplementação. REV BRAS MED ESPORTE 2009. [DOI: 10.1590/s1517-86922009000600015] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
A glutamina é o aminoácido livre mais abundante no plasma e no tecido muscular. Nutricionalmente é classificada como um aminoácido não essencial, uma vez que pode ser sintetizada pelo organismo a partir de outros aminoácidos. A glutamina está envolvida em diferentes funções, tais como a proliferação e desenvolvimento de células, o balanço acidobásico, o transporte da amônia entre os tecidos, a doação de esqueletos de carbono para a gliconeogênese, a participação no sistema antioxidante e outras. Por meio de técnicas de biologia molecular, estudos demonstram que a glutamina pode também influenciar diversas vias de sinalização celular, em especial a expressão de proteínas de choque térmico (HSPs). As HSPs contribuem para a manutenção da homeostasia da célula na presença de agentes estressores, tais como as espécies reativas de oxigênio (ERO). Em situações de elevado catabolismo muscular, como após exercícios físicos intensos e prolongados, a concentração de glutamina pode tornar-se reduzida. A menor disponibilidade desse aminoácido pode diminuir a resistência da célula a lesões, levando a processos de apoptose celular. Por essas razões, a suplementação com L-glutamina, tanto na forma livre, quanto como dipeptídeo, tem sido investigada. Alguns aspectos bioquímicos, metabólicos e mecanismos moleculares da glutamina, bem como os efeitos de sua suplementação, são abordados no presente trabalho.
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Danielyan L, Zellmer S, Sickinger S, Tolstonog GV, Salvetter J, Lourhmati A, Reissig DD, Gleiter CH, Gebhardt R, Buniatian GH. Keratinocytes as depository of ammonium-inducible glutamine synthetase: age- and anatomy-dependent distribution in human and rat skin. PLoS One 2009; 4:e4416. [PMID: 19204801 PMCID: PMC2637544 DOI: 10.1371/journal.pone.0004416] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 12/23/2008] [Indexed: 02/02/2023] Open
Abstract
In inner organs, glutamine contributes to proliferation, detoxification and establishment of a mechanical barrier, i.e., functions essential for skin, as well. However, the age-dependent and regional peculiarities of distribution of glutamine synthetase (GS), an enzyme responsible for generation of glutamine, and factors regulating its enzymatic activity in mammalian skin remain undisclosed. To explore this, GS localization was investigated using immunohistochemistry and double-labeling of young and adult human and rat skin sections as well as skin cells in culture. In human and rat skin GS was almost completely co-localized with astrocyte-specific proteins (e.g. GFAP). While GS staining was pronounced in all layers of the epidermis of young human skin, staining was reduced and more differentiated among different layers with age. In stratum basale and in stratum spinosum GS was co-localized with the adherens junction component beta-catenin. Inhibition of, glycogen synthase kinase 3beta in cultured keratinocytes and HaCaT cells, however, did not support a direct role of beta-catenin in regulation of GS. Enzymatic and reverse transcriptase polymerase chain reaction studies revealed an unusual mode of regulation of this enzyme in keratinocytes, i.e., GS activity, but not expression, was enhanced about 8-10 fold when the cells were exposed to ammonium ions. Prominent posttranscriptional up-regulation of GS activity in keratinocytes by ammonium ions in conjunction with widespread distribution of GS immunoreactivity throughout the epidermis allows considering the skin as a large reservoir of latent GS. Such a depository of glutamine-generating enzyme seems essential for continuous renewal of epidermal permeability barrier and during pathological processes accompanied by hyperammonemia.
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Affiliation(s)
- Lusine Danielyan
- Department of Clinical Pharmacology, University Hospital of Tübingen, Tübingen, Germany
| | - Sebastian Zellmer
- Institute of Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Stefan Sickinger
- Institute of Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Genrich V. Tolstonog
- Heinrich-Pette-Institute for Experimental Virology and Immunology, Hamburg, Germany
| | | | - Ali Lourhmati
- Department of Clinical Pharmacology, University Hospital of Tübingen, Tübingen, Germany
| | | | - Cristoph H. Gleiter
- Department of Clinical Pharmacology, University Hospital of Tübingen, Tübingen, Germany
| | - Rolf Gebhardt
- Institute of Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany
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Refeeding concomitant with glutamine supplementation only decreases muscle glutamine synthesis without body weight recovery in very old fasted male rats. Clin Nutr 2008; 27:670. [DOI: 10.1016/j.clnu.2008.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 04/23/2008] [Accepted: 04/24/2008] [Indexed: 11/19/2022]
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Mignon M, Beaufrère AM, Combaret L, Meynial-Denis D. Does long-term intermittent treatment with glutamine improve the well-being of fed and fasted very old rats? JPEN J Parenter Enteral Nutr 2008; 31:456-62. [PMID: 17947599 DOI: 10.1177/0148607107031006456] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Glutamine is known to have a specific role in very old rats (>25 months of age). For this reason, we have orally supplemented female rats with glutamine (20% of diet protein) intermittently. The treatment started before animals became very old and lasted 5 months. Very old rats were studied in fed state or after 5-day fasting after the last glutamine cure. The aim of this study was to determine whether this in vivo pretreatment improves the well-being of very old rats (muscle sarcopenia decrease, gut integrity improvement, decrease of the known up-regulated glutamine synthetase observed regardless of nutrition state). METHODS Protein turnover was measured in epitrochlearis muscle, whereas glutamine synthetase (GS) activities were assessed in tibialis anterior muscle from fed and 5-days-fasted female Wistar adult (6 months) and very old (27 months) rats, pretreated or not with glutamine. Furthermore, gut was dissected and weighed. RESULTS Long-term treatment with glutamine had positive effects on very old rats: (1) it prevented the loss of body weight, but, (2) it did not prevent the inevitable sarcopenia regardless of nutrition state, and (3) it maintained the gut mass. Surprisingly, the muscle up-regulated GS activity observed in fed and fasted very old rats was only decreased in the fed state when rats were supplemented, without change in plasma and muscle glutamine concentrations. CONCLUSIONS Long-term treatment with glutamine started before advanced age had essentially a beneficial role on the gut. It may play a role in maintaining intestine integrity and intestinal immune function. Further investigations would be warranted to explore these mechanisms.
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Affiliation(s)
- Michelle Mignon
- INRA, UMR 1019, Human Nutrition Unit, Saint Genes-Champanelle, France
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Spindler SR, Dhahbi JM. Conserved and tissue-specific genic and physiologic responses to caloric restriction and altered IGFI signaling in mitotic and postmitotic tissues. Annu Rev Nutr 2007; 27:193-217. [PMID: 17428180 DOI: 10.1146/annurev.nutr.27.061406.093743] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Caloric restriction (CR), the consumption of fewer calories without malnutrition, and reduced insulin and/or IGFI receptor signaling delay many age-related physiological changes and extend the lifespan of many model organisms. Here, we present and review microarray and biochemical studies indicating that the potent anticancer effects of CR and disrupted insulin/IGFI receptor signaling evolved as a byproduct of the role of many mitotic tissues as reservoirs of metabolic energy. We argue that the longevity effects of CR are derived from repeated cycles of apoptosis and autophagic cell death in mitotically competent tissues and protein turnover and cellular repair in postmitotic tissues. We review studies showing that CR initiated late in life can rapidly induce many of the benefits of lifelong CR, including its anticancer effects. We also discuss evidence from liver and heart indicating that many benefits of lifelong CR are recapitulated in mitotic and postmitotic tissues when CR is initiated late in life.
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Affiliation(s)
- Stephen R Spindler
- Department of Biochemistry, University of California, Riverside, CA 92521, USA.
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Mignon M, Lêvêque L, Bonnel E, Meynial-Denis D. Does glutamine supplementation decrease the response of muscle glutamine synthesis to fasting in muscle in adult and very old rats? JPEN J Parenter Enteral Nutr 2007; 31:26-31. [PMID: 17202437 DOI: 10.1177/014860710703100126] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Glutamine synthetase (GS), a key enzyme in the production of glutamine, is preserved in rat skeletal muscle during aging but is increased with advanced age in vivo. The aim of this study was to determine whether glutamine supplementation affects up-regulation of GS by fasting in vivo in adult and very old female rats. METHODS Muscle GS activities were assessed in 5-day-fasted female Wistar adult (6 months) and very old (27 months) rats refed and supplemented with glutamine or other amino acids (alanine or glycine). Fed rats were used to investigate the possible effect of glutamine supplementation in the fed state. RESULTS After 5 days' fasting, the up-regulated GS activity was decreased whatever the type of amino acid supplementation (glutamine, alanine, and glycine) in adults, whereas it was only decreased by glutamine supplementation in very old rats). In the fed state, no effect of glutamine supplementation was observed even if GS activity remained up-regulated whatever the age and the period of supplementation. CONCLUSIONS These results confirm that glutamine has a specific role in very old rats. The up-regulated GS activity was decreased by an exogenous supply of glutamine only if intramuscular glutamine was depleted; this was confirmed by studies in the fed state. The up-regulated GS activity in both fed and fasted rats may be associated with increased glutamine requirements in the whole body.
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Arborelius L, Eklund MB. Both long and brief maternal separation produces persistent changes in tissue levels of brain monoamines in middle-aged female rats. Neuroscience 2007; 145:738-50. [PMID: 17222517 DOI: 10.1016/j.neuroscience.2006.12.007] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 11/14/2006] [Accepted: 12/04/2006] [Indexed: 12/25/2022]
Abstract
Adverse experiences early in life are associated with an increased incidence of later psychopathology including depression. Based on evidence that dysfunction of central monoaminergic systems is involved in the pathophysiology of depression, we hypothesize that early adversity could negatively affect these systems. To test this we have investigated the effects of maternal separation, which has been suggested to model early-life stress and the development of a depression-like syndrome in the rat, on brain monoaminergic systems. Since depression is more common in women and the risk of developing this disorder appears to increase with age, we have studied such effects in middle-aged female rats. Rat pups were separated for 180 min (long maternal separation; LMS) or 15 min (brief maternal separation; BMS, often referred to as neonatal handling) twice daily for 2 weeks postpartum. An animal facility-reared (AFR) group was also included. At 15 months of age tissue levels of monoamines and their metabolites in several different brain regions were analyzed. In the LMS females tissue levels of both 5-HT and 5-hydroxyindole acetic acid (5-HIAA) were significantly increased in the dorsal raphe nucleus, and 5-HIAA and homovanillic acid levels were also elevated in the nucleus accumbens as compared with AFR and BMS rats. In the cingulate cortex both LMS and BMS decreased noradrenaline (NA) levels, although this effect was more pronounced in the LMS rats. On the other hand, BMS decreased 5-HT, 5-HIAA, dopamine (DA) as well as NA levels in the amygdala and produced an increase in DA levels in response to acute stress in the hypothalamus, an effect not seen in AFR rats. Our results demonstrate that LMS produced persistent alterations in both serotonergic, noradrenergic and dopaminergic systems in brain regions that have been suggested to be implicated in the pathophysiology of depression. In addition, BMS affected brain monoaminergic levels mainly in the amygdala.
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Affiliation(s)
- L Arborelius
- Department of Neuroscience, Section for Behavioural Neuroscience, Karolinska Institutet, S-171 77 Stockholm, Sweden.
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