1
|
Liang R, Xiang Q, Dai M, Lin T, Xie D, Song Q, Liu Y, Yue J. Identification of nicotinamide N-methyltransferase as a promising therapeutic target for sarcopenia. Aging Cell 2024:e14236. [PMID: 38838088 DOI: 10.1111/acel.14236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 05/18/2024] [Accepted: 05/20/2024] [Indexed: 06/07/2024] Open
Abstract
Sarcopenia is a significant geriatric syndrome that involves the loss of skeletal muscle mass and strength. Due to its substantial endocrine role, the metabolic microenvironment of skeletal muscle undergoes changes with age. Examining the pathogenesis of sarcopenia through focusing on metabolic dysregulation could offer insights for developing more effective intervention strategies. In this study, we analyzed the transcriptomics data to identify specific genes involved in the regulation of metabolism in skeletal muscle during the development of sarcopenia. Three machine learning algorithms were employed to screen key target genes exhibiting strong correlations with metabolism, which were further validated using RNA-sequencing data and publicly accessible datasets. Among them, the metabolic enzyme nicotinamide N-methyltransferase (NNMT) was elevated in sarcopenia, and predicted sarcopenia with an area under the curve exceeding 0.7, suggesting it as a potential therapeutic target for sarcopenia. As expected, inhibition of NNMT improved the grip strength in aging mice and alleviated age-related decline in the mass index of the quadriceps femoris muscles and whole-body lean mass index. Additionally, the NNMTi treatment increased the levels of nicotinamide adenine dinucleotide (NAD+) content, as well as PGC1α and p-AMPK expression in the muscles of both the D-galactose-treated mouse model and naturally aging mouse model. Overall, this work demonstrates NNMT as a promising target for preventing age-related decline in muscle mass and strength.
Collapse
Affiliation(s)
- Rui Liang
- Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Qiao Xiang
- Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Miao Dai
- Department of Geriatrics, Jiujiang No 1 People's Hospital, Jiujiang, Jiangxi, China
| | - Taiping Lin
- Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Dongmei Xie
- Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Quhong Song
- Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Yu Liu
- National Clinical Research Center for Geriatrics, General Practice Ward/International Medical Center Ward, General Practice Medical Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Jirong Yue
- Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| |
Collapse
|
2
|
Prado CM, Batsis JA, Donini LM, Gonzalez MC, Siervo M. Sarcopenic obesity in older adults: a clinical overview. Nat Rev Endocrinol 2024; 20:261-277. [PMID: 38321142 DOI: 10.1038/s41574-023-00943-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/15/2023] [Indexed: 02/08/2024]
Abstract
Sarcopenic obesity is characterized by a concurrent decline in muscle mass and function, along with increased adipose tissue. Sarcopenic obesity is a growing concern in older adults owing to significant health consequences, including implications for mortality, comorbidities and risk of developing geriatric syndromes. A 2022 consensus statement established a new definition and diagnostic criteria for sarcopenic obesity. The pathophysiology of this condition involves a complex interplay between muscle, adipose tissue, hormonal changes, inflammation, oxidative stress and lifestyle factors, among others. Sarcopenic obesity is treated with a range of management approaches, such as lifestyle interventions, exercise, nutrition and medical therapies. Emerging therapies that were developed for treating other conditions may be relevant to sarcopenic obesity, including novel pharmacological agents and personalized approaches such as precision medicine. In this Review, we synthesize the current knowledge of the clinical importance of sarcopenic obesity, its assessment and diagnosis, along with current and emerging management strategies.
Collapse
Affiliation(s)
- Carla M Prado
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
| | - John A Batsis
- Division of Geriatric Medicine, School of Medicine, and Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Lorenzo M Donini
- Department of Experimental Medicine, Sapienza University, Rome, Italy
| | - M Cristina Gonzalez
- Postgraduate Program in Nutrition and Food, Pelotas, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Mario Siervo
- School of Population Health, Curtin University, Perth, Western Australia, Australia
- Curtin Dementia Centre of Excellence, enAble Institute, Curtin University, Perth, Western Australia, Australia
| |
Collapse
|
3
|
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.
Collapse
|
4
|
Fountain WA, Bopp TS, Bene M, Walston JD. Metabolic dysfunction and the development of physical frailty: an aging war of attrition. GeroScience 2024:10.1007/s11357-024-01101-7. [PMID: 38400874 DOI: 10.1007/s11357-024-01101-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 02/13/2024] [Indexed: 02/26/2024] Open
Abstract
The World Health Organization recently declared 2021-2030 the decade of healthy aging. Such emphasis on healthy aging requires an understanding of the biologic challenges aging populations face. Physical frailty is a syndrome of vulnerability that puts a subset of older adults at high risk for adverse health outcomes including functional and cognitive decline, falls, hospitalization, and mortality. The physiology driving physical frailty is complex with age-related biological changes, dysregulated stress response systems, chronic inflammatory pathway activation, and altered energy metabolism all likely contributing. Indeed, a series of recent studies suggests circulating metabolomic distinctions can be made between frail and non-frail older adults. For example, marked restrictions on glycolytic and mitochondrial energy production have been independently observed in frail older adults and collectively appear to yield a reliance on the highly fatigable ATP-phosphocreatine (PCr) energy system. Further, there is evidence that age-associated impairments in the primary ATP generating systems (glycolysis, TCA cycle, electron transport) yield cumulative deficits and fail to adequately support the ATP-PCr system. This in turn may acutely contribute to several major components of the physical frailty phenotype including muscular fatigue, weakness, slow walking speed and, over time, result in low physical activity and accelerate reductions in lean body mass. This review describes specific age-associated metabolic declines and how they can collectively lead to metabolic inflexibility, ATP-PCr reliance, and the development of physical frailty. Further investigation remains necessary to understand the etiology of age-associated metabolic deficits and develop targeted preventive strategies that maintain robust metabolic health in older adults.
Collapse
Affiliation(s)
- William A Fountain
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
| | - Taylor S Bopp
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
| | - Michael Bene
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
| | - Jeremy D Walston
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA.
| |
Collapse
|
5
|
Shoemaker ME, Gillen ZM, Fukuda DH, Cramer JT. Metabolic Flexibility and Inflexibility: Pathology Underlying Metabolism Dysfunction. J Clin Med 2023; 12:4453. [PMID: 37445488 DOI: 10.3390/jcm12134453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 06/29/2023] [Indexed: 07/15/2023] Open
Abstract
Metabolic flexibility can be defined as the ability of the skeletal muscle to adjust its utilization of substrate pathways [...].
Collapse
Affiliation(s)
- Marni E Shoemaker
- School of Health and Consumer Sciences, South Dakota State University, Brookings, SD 57007, USA
| | - Zachary M Gillen
- Department of Kinesiology, Mississippi State University, 180 Magruder Street, Mississippi State, MS 39762, USA
| | - David H Fukuda
- School of Kinesiology and Rehabilitation Sciences, University of Central Florida, Orlando, FL 32816, USA
| | - Joel T Cramer
- College of Health Professions and Sciences, University of Central Florida, Orlando, FL 32816, USA
| |
Collapse
|
6
|
Barros D, Marques EA, Magalhães J, Carvalho J. Energy metabolism and frailty: The potential role of exercise-induced myokines - A narrative review. Ageing Res Rev 2022; 82:101780. [PMID: 36334911 DOI: 10.1016/j.arr.2022.101780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 10/20/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022]
Abstract
Frailty is a complex condition that emerges from dysregulation in multiple physiological systems. Increasing evidence suggests the potential role of age-related energy dysregulation as a key driver of frailty. Exercise is considered the most efficacious intervention to prevent and even ameliorate frailty as it up-tunes and improves the function of several related systems. However, the mechanisms and molecules responsible for these intersystem benefits are not fully understood. The skeletal muscle is considered a secretory organ with endocrine functions that can produce and secrete exercise-related molecules such as myokines. These molecules are cytokines and other peptides released by muscle fibers in response to acute and/or chronic exercise. The available evidence supports that several myokines can elicit autocrine, paracrine, or endocrine effects, partly mediating inter-organ crosstalk and also having a critical role in improving cardiovascular, metabolic, immune, and neurological health. This review describes the current evidence about the potential link between energy metabolism dysregulation and frailty and provides a theoretical framework for the potential role of myokines (via exercise) in counteracting frailty. It also summarizes the physiological role of selected myokines and their response to different acute and chronic exercise protocols in older adults.
Collapse
Affiliation(s)
- Duarte Barros
- The Research Centre in Physical Activity, Health and Leisure, CIAFEL, University of Porto, Portugal; ITR - Laboratory for Integrative and Translational Research in Population Health, Porto, Portugal.
| | - Elisa A Marques
- Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, University of Maia (ISMAI), Portugal; School of Sport and Exercise Sciences, Loughborough University, Loughborough, UK
| | - José Magalhães
- The Research Centre in Physical Activity, Health and Leisure, CIAFEL, University of Porto, Portugal; ITR - Laboratory for Integrative and Translational Research in Population Health, Porto, Portugal
| | - Joana Carvalho
- The Research Centre in Physical Activity, Health and Leisure, CIAFEL, University of Porto, Portugal; ITR - Laboratory for Integrative and Translational Research in Population Health, Porto, Portugal
| |
Collapse
|
7
|
Nadamuni M, Venable AH, Huen SC. When a calorie isn't just a calorie: a revised look at nutrition in critically ill patients with sepsis and acute kidney injury. Curr Opin Nephrol Hypertens 2022; 31:358-366. [PMID: 35703214 PMCID: PMC9248034 DOI: 10.1097/mnh.0000000000000801] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW To discuss how nutritional management could be optimized to promote protective metabolism in sepsis and associated acute kidney injury. RECENT FINDINGS Recent evidence suggests that sepsis is a metabolically distinct critical illness and that certain metabolic alterations, such as activation of fasting metabolism, may be protective in bacterial sepsis. These findings may explain the lack of survival benefit in recent randomized controlled trials of nutrition therapy for critical illness. These trials are limited by cohort heterogeneity, combining both septic and nonseptic critical illness, and the use of inaccurate caloric estimates to determine energy requirements. These energy estimates are also unable to provide information on specific substrate preferences or the capacity for substrate utilization. As a result, high protein feeding beyond the capacity for protein synthesis could cause harm in septic patients. Excess glucose and insulin exposures suppress fatty acid oxidation, ketogenesis and autophagy, of which emerging evidence suggest are protective against sepsis associated organ damage such as acute kidney injury. SUMMARY Distinguishing pathogenic and protective sepsis-related metabolic changes are critical to enhancing and individualizing nutrition management for critically ill patients.
Collapse
Affiliation(s)
| | | | - Sarah C Huen
- Department of Internal Medicine
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| |
Collapse
|
8
|
Shoemaker ME, Pereira SL, Mustad VA, Gillen ZM, McKay BD, Lopez-Pedrosa JM, Rueda R, Cramer JT. Differences in muscle energy metabolism and metabolic flexibility between sarcopenic and nonsarcopenic older adults. J Cachexia Sarcopenia Muscle 2022; 13:1224-1237. [PMID: 35178889 PMCID: PMC8978004 DOI: 10.1002/jcsm.12932] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 12/17/2021] [Accepted: 01/10/2022] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Metabolic flexibility is the ability of skeletal muscle to adapt fuel utilization to the demand for fuel sources [carbohydrates (CHO) and fats (FAT)]. The purpose of this study was to explore muscle energy metabolism and metabolic flexibility under various conditions in sarcopenic (S) versus nonsarcopenic (NS) older adults. METHODS Twenty-two older adults aged 65 years or older were categorized as NS [n = 11; mean ± standard deviation (SD); age = 73.5 ± 6.0 years (males, n = 5; females, n = 6)] or S [n = 11; 81.2 ± 10.5 years (males, n = 6; females, n = 5) based on handgrip strength, body composition and physical performance. Indirect calorimetry was recorded before and after consumption of a high-CHO meal and during aerobic and anaerobic exercise. Respiratory quotient (RQ), CHO and FAT oxidation were assessed. Venous blood samples were collected for glucose and insulin concentrations. RESULTS At rest, compared with NS, S exhibited a 5-8% higher RQ at 0 (0.72 vs. 0.76) and 120 (0.77 vs. 0.82), 150 (0.76 vs. 0.80), and 180 min (0.74 vs. 0.80) (P = 0.002-0.025); 59-195% higher CHO oxidation at 0, 120, and 180 min (0.0004-0.002 vs. 0.001-0.002 g·min-1 ·kg-1) (P = 0.010-0.047); and 20-31% lower FAT oxidation at 0, 15, and 90-180 min (0.0009-0.0022 vs. 0.0011-0.002 g·min-1 ·kg-1 ) (P = 0.004-0.038). Glucose levels were significantly elevated in S versus NS at 0, 60 and 75 min (144.64-202.78 vs. 107.70-134.20 mg·dL-1 ) but not insulin. During aerobic exercise, RQ was 5% greater (0.90 vs. 0.86) (P = 0.039), and FAT oxidation was 35% lower at 6-8 min (0.003 vs. 0.005 g·min-1 ·kg-1 ) (P = 0.033) in S versus NS. During anaerobic exercise, CHO oxidation was 31% greater in NS versus S at 60-80% time to exhaustion (0.011 vs. 0.007 g·min-1 ·kg-1 ) (P = 0.015). Per cent contribution to energy expenditure was greater in S for CHO but lower for FAT at 0 (CHO: 22% vs. 10%; FAT: 78% vs. 91%) and 120-180 min (CHO: 35-42% vs. 17-25%; FAT: 58-65% vs. 75%-84%) (P = 0.003-0.046) at rest and 6-8 min during aerobic exercise (CHO: 70% vs. 57%; FAT: 30% vs. 45%) (P = 0.046). CONCLUSIONS The data show differences in skeletal muscle energy metabolism and substrate utilization between S and NS at rest, transitioning from fasted to fed state, and during exercise. Compared with NS, S displayed a diminished ability to adapt fuel utilization in response to feeding and exercise, reflecting metabolic inflexibility. Impaired metabolic flexibility could be a mechanism underlying the losses of strength and physical function accompanying sarcopenia.
Collapse
Affiliation(s)
- Marni E Shoemaker
- College of Health Sciences, The University of Texas at El Paso, El Paso, TX, USA
| | | | | | - Zachary M Gillen
- Department of Kinesiology, Mississippi State University, Mississippi State, MS, USA
| | - Brianna D McKay
- Department of Health Professions, Creighton University School of Medicine, Omaha, NE, USA
| | | | | | - Joel T Cramer
- College of Health Sciences, The University of Texas at El Paso, El Paso, TX, USA
| |
Collapse
|