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Shoveller AK, Pezzali JG, House JD, Bertolo RF, Pencharz PB, Ball RO. Methionine and cysteine oxidation are regulated in a dose dependent manner by dietary Cys intake in neonatal piglets receiving enteral nutrition. PLoS One 2022; 17:e0275760. [PMID: 36301815 PMCID: PMC9612549 DOI: 10.1371/journal.pone.0275760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 09/22/2022] [Indexed: 11/18/2022] Open
Abstract
Methionine (Met) is an indispensable amino acid (AA) in piglets. Met can synthesize cysteine (Cys), and Cys has the ability to reduce the Met requirement by 40% in piglets. However, whether this sparing effect on Met is facilitated by downregulation of Cys synthesis has not been shown. This study investigated the effects of graded levels of Cys on Met and Cys oxidation, and on plasma AA concentrations. Piglets (n = 32) received a complete elemental diet via gastric catheters prior to being randomly assigned to one of the eight dietary Cys levels (0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.40, 0.50 g kg-1d-1) with an adequate Met concentration (0.25g kg-1d-1). Constant infusion of L-[1-14C]-Met and L-[1-14C]-Cys were performed for 6 h on d 6 and d 8 to determine Met and Cys oxidation, respectively. Met oxidation decreased as Cys intake increased (P<0.05). At higher Cys intakes (0.15 to 0.5g kg-1d-1), Met oxidation decreased (P<0.05) at a slower rate. Cys oxidation was similar (P>0.05) among dietary Cys intakes; however, a significant polynomial relationship was observed between Cys oxidation and intake (P<0.05, R2 = 0.12). Plasma Met concentrations increased (P<0.05) linearly with increasing levels of dietary Cys, while plasma Cys concentrations changed (P<0.05) in a cubic manner and the highest concentrations occurred at the highest intake levels. Increasing dietary levels of Cys resulted in a reduction in Met oxidation until the requirement for the total sulfur AA was met, indicating the sparing capacity by Cys of Met occurs through inhibition of the transsulfuration pathway in neonatal piglets.
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Affiliation(s)
- Anna K. Shoveller
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
| | - Julia G. Pezzali
- Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada
| | - James D. House
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Robert F. Bertolo
- Department of Biochemistry, Memorial University of Newfoundland, St. John’s, Newfoundland, Canada
| | - Paul B. Pencharz
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
- The Research Institute, The Hospital for Sick Children, Toronto, Canada
- Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Ronald O. Ball
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
- The Research Institute, The Hospital for Sick Children, Toronto, Canada
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada
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2
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Nishimura Y, Musa I, Holm L, Lai YC. Recent advances in measuring and understanding the regulation of exercise-mediated protein degradation in skeletal muscle. Am J Physiol Cell Physiol 2021; 321:C276-C287. [PMID: 34038244 DOI: 10.1152/ajpcell.00115.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Skeletal muscle protein turnover plays a crucial role in controlling muscle mass and protein quality control, including sarcomeric (structural and contractile) proteins. Protein turnover is a dynamic and continual process of protein synthesis and degradation. The ubiquitin proteasome system (UPS) is a key degradative system for protein degradation and protein quality control in skeletal muscle. UPS-mediated protein quality control is known to be impaired in aging and diseases. Exercise is a well-recognized, nonpharmacological approach to promote muscle protein turnover rates. Over the past decades, we have acquired substantial knowledge of molecular mechanisms of muscle protein synthesis after exercise. However, there have been considerable gaps in the mechanisms of how muscle protein degradation is regulated at the molecular level. The main challenge to understand muscle protein degradation is due in part to the lack of solid stable isotope tracer methodology to measure muscle protein degradation rate. Understanding the mechanisms of UPS with the concomitant measurement of protein degradation rate in skeletal muscle will help identify novel therapeutic strategies to ameliorate impaired protein turnover and protein quality control in aging and diseases. Thus, the goal of this present review was to highlight how recent advances in the field may help improve our understanding of exercise-mediated protein degradation. We discuss 1) the emerging roles of protein phosphorylation and ubiquitylation modifications in regulating proteasome-mediated protein degradation after exercise and 2) methodological advances to measure in vivo myofibrillar protein degradation rate using stable isotope tracer methods.
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Affiliation(s)
- Yusuke Nishimura
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Ibrahim Musa
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Lars Holm
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- MRC Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom
| | - Yu-Chiang Lai
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- MRC Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom
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3
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Mert S, Bulutoglu B, Chu C, Dylewski M, Lin FM, Yu YM, Yarmush ML, Sheridan RL, Uygun K. Multiorgan Metabolomics and Lipidomics Provide New Insights Into Fat Infiltration in the Liver, Muscle Wasting, and Liver-Muscle Crosstalk Following Burn Injury. J Burn Care Res 2020; 42:269-287. [PMID: 32877506 DOI: 10.1093/jbcr/iraa145] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Burn injury mediated hypermetabolic syndrome leads to increased mortality among severe burn victims, due to liver failure and muscle wasting. Metabolic changes may persist up to 2 years following the injury. Thus, understanding the underlying mechanisms of the pathology is crucially important to develop appropriate therapeutic approaches. We present detailed metabolomic and lipidomic analyses of the liver and muscle tissues in a rat model with a 30% body surface area burn injury located at the dorsal skin. Three hundred and thirty-eight of 1587 detected metabolites and lipids in the liver and 119 of 1504 in the muscle tissue exhibited statistically significant alterations. We observed excessive accumulation of triacylglycerols, decreased levels of S-adenosylmethionine, increased levels of glutamine and xenobiotics in the liver tissue. Additionally, the levels of gluconeogenesis, glycolysis, and tricarboxylic acid cycle metabolites are generally decreased in the liver. On the other hand, burn injury muscle tissue exhibits increased levels of acyl-carnitines, alpha-hydroxyisovalerate, ophthalmate, alpha-hydroxybutyrate, and decreased levels of reduced glutathione. The results of this preliminary study provide compelling observations that liver and muscle tissues undergo distinctly different changes during hypermetabolism, possibly reflecting liver-muscle crosstalk. The liver and muscle tissues might be exacerbating each other's metabolic pathologies, via excessive utilization of certain metabolites produced by each other.
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Affiliation(s)
- Safak Mert
- Burns Department, Shriners Hospitals for Children, Boston, Massachusetts.,Department of Surgery, Center for Engineering in Medicine and Surgery, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Beyza Bulutoglu
- Burns Department, Shriners Hospitals for Children, Boston, Massachusetts.,Department of Surgery, Center for Engineering in Medicine and Surgery, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Christopher Chu
- Burns Department, Shriners Hospitals for Children, Boston, Massachusetts.,Department of Surgery, Center for Engineering in Medicine and Surgery, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Maggie Dylewski
- Burns Department, Shriners Hospitals for Children, Boston, Massachusetts
| | - Florence M Lin
- Burns Department, Shriners Hospitals for Children, Boston, Massachusetts
| | - Yong-Ming Yu
- Burns Department, Shriners Hospitals for Children, Boston, Massachusetts.,Department of Surgery, Center for Engineering in Medicine and Surgery, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Martin L Yarmush
- Burns Department, Shriners Hospitals for Children, Boston, Massachusetts.,Department of Surgery, Center for Engineering in Medicine and Surgery, Massachusetts General Hospital, Harvard Medical School, Boston.,Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey
| | - Robert L Sheridan
- Burns Department, Shriners Hospitals for Children, Boston, Massachusetts
| | - Korkut Uygun
- Burns Department, Shriners Hospitals for Children, Boston, Massachusetts.,Department of Surgery, Center for Engineering in Medicine and Surgery, Massachusetts General Hospital, Harvard Medical School, Boston
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4
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Suriben R, Chen M, Higbee J, Oeffinger J, Ventura R, Li B, Mondal K, Gao Z, Ayupova D, Taskar P, Li D, Starck SR, Chen HIH, McEntee M, Katewa SD, Phung V, Wang M, Kekatpure A, Lakshminarasimhan D, White A, Olland A, Haldankar R, Solloway MJ, Hsu JY, Wang Y, Tang J, Lindhout DA, Allan BB. Antibody-mediated inhibition of GDF15-GFRAL activity reverses cancer cachexia in mice. Nat Med 2020; 26:1264-1270. [PMID: 32661391 DOI: 10.1038/s41591-020-0945-x] [Citation(s) in RCA: 150] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 05/20/2020] [Indexed: 01/09/2023]
Abstract
Cancer cachexia is a highly prevalent condition associated with poor quality of life and reduced survival1. Tumor-induced perturbations in the endocrine, immune and nervous systems drive anorexia and catabolic changes in adipose tissue and skeletal muscle, hallmarks of cancer cachexia2-4. However, the molecular mechanisms driving cachexia remain poorly defined, and there are currently no approved drugs for the condition. Elevation in circulating growth differentiation factor 15 (GDF15) correlates with cachexia and reduced survival in patients with cancer5-8, and a GDNF family receptor alpha like (GFRAL)-Ret proto-oncogene (RET) signaling complex in brainstem neurons that mediates GDF15-induced weight loss in mice has recently been described9-12. Here we report a therapeutic antagonistic monoclonal antibody, 3P10, that targets GFRAL and inhibits RET signaling by preventing the GDF15-driven interaction of RET with GFRAL on the cell surface. Treatment with 3P10 reverses excessive lipid oxidation in tumor-bearing mice and prevents cancer cachexia, even under calorie-restricted conditions. Mechanistically, activation of the GFRAL-RET pathway induces expression of genes involved in lipid metabolism in adipose tissues, and both peripheral chemical sympathectomy and loss of adipose triglyceride lipase protect mice from GDF15-induced weight loss. These data uncover a peripheral sympathetic axis by which GDF15 elicits a lipolytic response in adipose tissue independently of anorexia, leading to reduced adipose and muscle mass and function in tumor-bearing mice.
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Affiliation(s)
| | - Michael Chen
- NGM Biopharmaceuticals, South San Francisco, CA, USA
| | - Jared Higbee
- NGM Biopharmaceuticals, South San Francisco, CA, USA
| | | | | | - Betty Li
- NGM Biopharmaceuticals, South San Francisco, CA, USA
| | | | - Zhengyu Gao
- NGM Biopharmaceuticals, South San Francisco, CA, USA
| | - Dina Ayupova
- NGM Biopharmaceuticals, South San Francisco, CA, USA
| | | | - Diana Li
- NGM Biopharmaceuticals, South San Francisco, CA, USA
| | | | | | | | | | - Van Phung
- NGM Biopharmaceuticals, South San Francisco, CA, USA
| | - Marilyn Wang
- NGM Biopharmaceuticals, South San Francisco, CA, USA
| | | | | | | | | | - Raj Haldankar
- NGM Biopharmaceuticals, South San Francisco, CA, USA
| | | | - Jer-Yuan Hsu
- NGM Biopharmaceuticals, South San Francisco, CA, USA
| | - Yan Wang
- NGM Biopharmaceuticals, South San Francisco, CA, USA
| | - Jie Tang
- NGM Biopharmaceuticals, South San Francisco, CA, USA
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5
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Donadelli RA, Pezzali JG, Oba PM, Swanson KS, Coon C, Varney J, Pendlebury C, Shoveller AK. A commercial grain-free diet does not decrease plasma amino acids and taurine status but increases bile acid excretion when fed to Labrador Retrievers. Transl Anim Sci 2020; 4:txaa141. [PMID: 32832860 PMCID: PMC7433909 DOI: 10.1093/tas/txaa141] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 07/17/2020] [Indexed: 12/21/2022] Open
Abstract
Grain-free diets tend to have greater inclusions of pulses in contrast to grain-based diets. In 2018, the Food and Drug Administration (FDA) released a statement that grain-free diets may be related to the development of canine dilated cardiomyopathy (DCM). However, all dog foods met regulatory minimums for nutrient inclusion recommended by the Association of American Feed Controls Official. In some FDA case reports, but not all, dogs diagnosed with DCM also had low concentrations of plasma or whole blood taurine; thus, we hypothesized that feeding these diets will result in reduced taurine status from baseline measures. The objective of this study was to determine the effects of feeding a grain-free diet to large-breed dogs on taurine status and overall health. Eight Labrador Retrievers (four males and four females; Four Rivers Kennel, MO) were individually housed and fed a commercial complete and balanced grain-free diet (Acana Pork and Squash formula; APS) for 26 wk. Fasted blood samples were collected prior to the start of the trial (baseline; week 0) and at weeks 13 and 26 for analyses of blood chemistry, hematology, plasma amino acids, and whole blood taurine. Urine was collected by free catch at weeks 0 and 26 for taurine and creatinine analyses. Fresh fecal samples were collected at weeks 0 and 26 for bile acid analyses. Data were analyzed using the GLIMMIX procedure with repeated measures in SAS (v. 9.4). Plasma His, Met, Trp, and taurine and whole blood taurine concentrations increased over the course of the study (P < 0.05). Urinary taurine to creatinine ratio was not affected by diet (P > 0.05). Fecal bile acid excretion increased after 26 wk of feeding APS to dogs. Despite the higher fecal excretion of bile acids, plasma and whole blood taurine increased over the 26-wk feeding study. These data suggest that feeding APS, a grain-free diet, over a 26-wk period improved taurine status in Labrador Retrievers and is not the basis for the incidence of DCM for dogs fed APS. Other factors that may contribute to the etiology of DCM should be explored.
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Affiliation(s)
- Renan A Donadelli
- Animal Biosciences Department, University of Guelph, Guelph, ON, Canada
| | - Julia G Pezzali
- Animal Biosciences Department, University of Guelph, Guelph, ON, Canada
| | - Patricia M Oba
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL
| | - Kelly S Swanson
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL
| | | | | | | | - Anna K Shoveller
- Animal Biosciences Department, University of Guelph, Guelph, ON, Canada
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6
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Koshikawa M, Harada M, Noyama S, Kiyono K, Motoike Y, Nomura Y, Nishimura A, Izawa H, Watanabe E, Ozaki Y. Association between inflammation and skeletal muscle proteolysis, skeletal mass and strength in elderly heart failure patients and their prognostic implications. BMC Cardiovasc Disord 2020; 20:228. [PMID: 32414332 PMCID: PMC7229573 DOI: 10.1186/s12872-020-01514-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Accepted: 05/10/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Inflammation and skeletal muscle wasting often coexist in elderly populations, but few studies have examined their relationship in elderly heart failure (HF) patients. This study examined the relationship between inflammation and increased skeletal muscle proteolysis, reduced skeletal mass and strength, and their prognostic implications in elderly HF patients (> 65 years) using a random forest approach. METHODS We prospectively enrolled consecutive elderly HF patients (n = 78) and age- and sex-matched control subjects (n = 83). We measured the interleukin (IL)-6, C-reactive protein (CRP), and B-type natriuretic peptide (BNP) levels, lower limb muscle mass and strength, and 6-min walk distance. The amount of muscle proteolysis was determined by urinary 3-methylhystidine, normalized by creatinine (3-MH/Cr). The composite endpoint was defined as all-cause death or hospitalizations due to worsening HF. RESULTS Compared to controls, elderly HF patients had a significantly higher IL-6, CRP, BNP, and 3-MH/Cr, and exhibited a reduced lower limb muscle mass and strength. A correlation analysis demonstrated significant positive correlations between the inflammatory cytokine levels and 3-MH/Cr and BNP, and negative correlations with the lower limb muscle mass and strength, and 6-min walk distance. During a median follow-up of 2.4-years, 24 patients reached the endpoint. A random forest model revealed that inflammatory cytokines, skeletal muscle wasting, and the BNP had greater effects on the risk prediction. The algorithm achieved an area under the receiver operating characteristic curve of 0.887 (95% CI, 0.772-1.000). CONCLUSION This study provided evidence of the association between inflammation and increased skeletal muscle proteolysis, reduced skeletal mass and strength, and their prognostic roles in elderly HF patients.
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Affiliation(s)
- Masayuki Koshikawa
- Department of Cardiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Masahide Harada
- Department of Cardiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Shunsuke Noyama
- Division of Bioengineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Japan
| | - Ken Kiyono
- Division of Bioengineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Japan
| | - Yuji Motoike
- Department of Cardiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Yoshihiro Nomura
- Department of Cardiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Asuka Nishimura
- Department of Cardiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Hideo Izawa
- Department of Cardiology, Fujita Health University School of Medicine, Bantane Hospital, Nagoya, Japan
| | - Eiichi Watanabe
- Department of Cardiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan.
| | - Yukio Ozaki
- Department of Cardiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
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7
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Holm L, Dideriksen K, Nielsen RH, Doessing S, Bechshoeft RL, Højfeldt G, Moberg M, Blomstrand E, Reitelseder S, van Hall G. An exploration of the methods to determine the protein-specific synthesis and breakdown rates in vivo in humans. Physiol Rep 2019; 7:e14143. [PMID: 31496135 PMCID: PMC6732504 DOI: 10.14814/phy2.14143] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 05/08/2019] [Accepted: 05/09/2019] [Indexed: 01/02/2023] Open
Abstract
The present study explores the methods to determine human in vivo protein-specific myofibrillar and collagenous connective tissue protein fractional synthesis and breakdown rates. We found that in human myofibrillar proteins, the protein-bound tracer disappearance method to determine the protein fractional breakdown rate (FBR) (via 2 H2 O ingestion, endogenous labeling of 2 H-alanine that is incorporated into proteins, and FBR quantified by its disappearance from these proteins) has a comparable intrasubject reproducibility (range: 0.09-53.5%) as the established direct-essential amino acid, here L-ring-13 C6 -phenylalanine, incorporation method to determine the muscle protein fractional synthesis rate (FSR) (range: 2.8-56.2%). Further, the determination of the protein breakdown in a protein structure with complex post-translational processing and maturation, exemplified by human tendon tissue, was not achieved in this experimentation, but more investigation is encouraged to reveal the possibility. Finally, we found that muscle protein FBR measured with an essential amino acid tracer prelabeling is inappropriate presumably because of significant and prolonged intracellular recycling, which also may become a significant limitation for determination of the myofibrillar FSR when repeated infusion trials are completed in the same participants.
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Affiliation(s)
- Lars Holm
- Institute of Sports Medicine and Department of Orthopedic Surgery MBispebjerg HospitalCopenhagenDenmark
- Department of Biomedical SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
- School of Sport, Exercise and Rehabilitation SciencesUniversity of BirminghamBirminghamUnited Kingdom
| | - Kasper Dideriksen
- Institute of Sports Medicine and Department of Orthopedic Surgery MBispebjerg HospitalCopenhagenDenmark
| | - Rie H. Nielsen
- Institute of Sports Medicine and Department of Orthopedic Surgery MBispebjerg HospitalCopenhagenDenmark
| | - Simon Doessing
- Institute of Sports Medicine and Department of Orthopedic Surgery MBispebjerg HospitalCopenhagenDenmark
| | - Rasmus L. Bechshoeft
- Institute of Sports Medicine and Department of Orthopedic Surgery MBispebjerg HospitalCopenhagenDenmark
- Department of Biomedical SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Grith Højfeldt
- Institute of Sports Medicine and Department of Orthopedic Surgery MBispebjerg HospitalCopenhagenDenmark
| | - Marcus Moberg
- Aastrand LaboratorySwedish School of Sport and Health SciencesStockholmSweden
| | - Eva Blomstrand
- Aastrand LaboratorySwedish School of Sport and Health SciencesStockholmSweden
- Department of Physiology and PharmacologyKarolinska InstitutetStockholmSweden
| | - Søren Reitelseder
- Institute of Sports Medicine and Department of Orthopedic Surgery MBispebjerg HospitalCopenhagenDenmark
| | - Gerrit van Hall
- Department of Biomedical SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
- Clinical Metabolomics Core FacilityDepartment of Clinical Biochemistry, RigshospitaletCopenhagenDenmark
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8
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Wiesenthal AA, Müller C, Harder K, Hildebrandt JP. Alanine, proline and urea are major organic osmolytes in the snail Theodoxus fluviatilis under hyperosmotic stress. ACTA ACUST UNITED AC 2019; 222:jeb.193557. [PMID: 30606797 DOI: 10.1242/jeb.193557] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 12/18/2018] [Indexed: 01/02/2023]
Abstract
Hyperosmotic stress may result in osmotic volume loss from the body to the environment in animals that cannot control the water permeability of their integument. Euryhaline animals (which have a wide tolerance range of environmental salinities) have generally evolved the ability to counteract cell volume shrinkage by accumulating inorganic and organic osmolytes within their cells to balance internal and external osmolalities. Molluscs use very different combinations of amino acids and amino acid derivatives to achieve this goal. Theodoxus fluviatilis is a neritid gastropod that is distributed not only in limnic habitats in Europe but also in brackish waters (e.g. along the shoreline of the Baltic Sea). Animals from brackish sites survive better in high salinities than animals from freshwater locations. The results of the present study indicate that these differences in salinity tolerance cannot be explained by differences in the general ability to accumulate amino acids as organic osmolytes. Although there may be differences in the metabolic pathways involved in osmolyte accumulation in foot muscle tissue, the two groups of animals accumulate amino acid mixtures equally well when stepwise acclimated to their respective maximum tolerable salinity for extended periods. Among these amino acids, alanine and proline, as well as the osmolyte urea, hold a special importance for cell volume preservation in T. fluviatilis under hyperosmotic stress. It is possible that the accumulation of various amino acids during hyperosmotic stress occurs via hydrolysis of storage proteins, while alanine and proline are probably newly synthesised under conditions of hyperosmotic stress in the animals.
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Affiliation(s)
- Amanda A Wiesenthal
- Animal Physiology and Biochemistry, Zoological Institute and Museum, University of Greifswald, Felix-Hausdorff-Strasse 1, D-17489 Greifswald, Germany
| | - Christian Müller
- Animal Physiology and Biochemistry, Zoological Institute and Museum, University of Greifswald, Felix-Hausdorff-Strasse 1, D-17489 Greifswald, Germany
| | - Katrin Harder
- Animal Physiology and Biochemistry, Zoological Institute and Museum, University of Greifswald, Felix-Hausdorff-Strasse 1, D-17489 Greifswald, Germany
| | - Jan-Peter Hildebrandt
- Animal Physiology and Biochemistry, Zoological Institute and Museum, University of Greifswald, Felix-Hausdorff-Strasse 1, D-17489 Greifswald, Germany
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9
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Abstract
Muscle protein breakdown (MPB) is an important metabolic component of muscle remodeling, adaptation to training, and increasing muscle mass. Degradation of muscle proteins occurs via the integration of three main systems—autophagy and the calpain and ubiquitin-proteasome systems. These systems do not operate independently, and the regulation is complex. Complete degradation of a protein requires some combination of the systems. Determination of MPB in humans is technically challenging, leading to a relative dearth of information. Available information on the dynamic response of MPB primarily comes from stable isotopic methods with expression and activity measures providing complementary information. It seems clear that resistance exercise increases MPB, but not as much as the increase in muscle protein synthesis. Both hyperaminoacidemia and hyperinsulinemia inhibit the post-exercise response of MPB. Available data do not allow a comprehensive examination of the mechanisms behind these responses. Practical nutrition recommendations for interventions to suppress MPB following exercise are often made. However, it is likely that some degree of increased MPB following exercise is an important component for optimal remodeling. At this time, it is not possible to determine the impact of nutrition on any individual muscle protein. Thus, until we can develop and employ better methods to elucidate the role of MPB following exercise and the response to nutrition, recommendations to optimize post exercise nutrition should focus on the response of muscle protein synthesis. The aim of this review is to provide a comprehensive examination of the state of knowledge, including methodological considerations, of the response of MPB to exercise and nutrition in humans.
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10
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Chan CYS, Roberts O, Rajoli RKR, Liptrott NJ, Siccardi M, Almond L, Owen A. Derivation of CYP3A4 and CYP2B6 degradation rate constants in primary human hepatocytes: A siRNA-silencing-based approach. Drug Metab Pharmacokinet 2018; 33:179-187. [PMID: 29921509 DOI: 10.1016/j.dmpk.2018.01.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 12/22/2017] [Accepted: 01/10/2018] [Indexed: 12/26/2022]
Abstract
The first-order degradation rate constant (kdeg) of cytochrome P450 (CYP) enzymes is a known source of uncertainty in the prediction of time-dependent drug-drug interactions (DDIs) in physiologically-based pharmacokinetic (PBPK) modelling. This study aimed to measure CYP kdeg using siRNA to suppress CYP expression in primary human hepatocytes followed by incubation over a time-course and tracking of protein expression and activity to observe degradation. The magnitude of gene knockdown was determined by qPCR and activity was measured by probe substrate metabolite formation and CYP2B6-Glo™ assay. Protein disappearance was determined by Western blotting. During a time-course of 96 and 60 h of incubation, over 60% and 76% mRNA knockdown was observed for CYP3A4 and CYP2B6, respectively. The kdeg of CYP3A4 and CYP2B6 protein was 0.0138 h-1 (±0.0023) and 0.0375 h-1 (±0.025), respectively. The kdeg derived from probe substrate metabolism activity was 0.0171 h-1 (±0.0025) for CYP3A4 and 0.0258 h-1 (±0.0093) for CYP2B6. The CYP3A4 kdeg values derived from protein disappearance and metabolic activity were in relatively good agreement with each other and similar to published values. This novel approach can now be used for other less well-characterised CYPs.
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Affiliation(s)
- Christina Y S Chan
- Department of Molecular and Clinical Pharmacology, The University of Liverpool, 70 Pembroke Place, Liverpool, L69 3GF, UK
| | - Owain Roberts
- Department of Molecular and Clinical Pharmacology, The University of Liverpool, 70 Pembroke Place, Liverpool, L69 3GF, UK
| | - Rajith K R Rajoli
- Department of Molecular and Clinical Pharmacology, The University of Liverpool, 70 Pembroke Place, Liverpool, L69 3GF, UK
| | - Neill J Liptrott
- Department of Molecular and Clinical Pharmacology, The University of Liverpool, 70 Pembroke Place, Liverpool, L69 3GF, UK
| | - Marco Siccardi
- Department of Molecular and Clinical Pharmacology, The University of Liverpool, 70 Pembroke Place, Liverpool, L69 3GF, UK
| | - Lisa Almond
- Simcyp (a Certara Company), Blades Enterprise Centre, John Street, Sheffield, S2 4SU, UK
| | - Andrew Owen
- Department of Molecular and Clinical Pharmacology, The University of Liverpool, 70 Pembroke Place, Liverpool, L69 3GF, UK.
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11
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Mitchell CJ, D'Souza RF, Mitchell SM, Figueiredo VC, Miller BF, Hamilton KL, Peelor FF, Coronet M, Pileggi CA, Durainayagam B, Fanning AC, Poppitt SD, Cameron-Smith D. Impact of dairy protein during limb immobilization and recovery on muscle size and protein synthesis; a randomized controlled trial. J Appl Physiol (1985) 2017; 124:717-728. [PMID: 29122965 DOI: 10.1152/japplphysiol.00803.2017] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Muscle disuse results in the loss of muscular strength and size, due to an imbalance between protein synthesis (MPS) and breakdown (MPB). Protein ingestion stimulates MPS, although it is not established if protein is able to attenuate muscle loss with immobilization (IM) or influence the recovery consisting of ambulatory movement followed by resistance training (RT). Thirty men (49.9 ± 0.6 yr) underwent 14 days of unilateral leg IM, 14 days of ambulatory recovery (AR), and a further six RT sessions over 14 days. Participants were randomized to consume an additional 20 g of dairy protein or placebo with a meal during the intervention. Isometric knee extension strength was reduced following IM (-24.7 ± 2.7%), partially recovered with AR (-8.6 ± 2.6%), and fully recovered after RT (-0.6 ± 3.4%), with no effect of supplementation. Thigh muscle cross-sectional area decreased with IM (-4.1 ± 0.5%), partially recovered with AR (-2.1 ± 0.5%), and increased above baseline with RT (+2.2 ± 0.5%), with no treatment effect. Myofibrillar MPS, measured using deuterated water, was unaltered by IM, with no effect of protein. During AR, MPS was increased only with protein supplementation. Protein supplementation did not attenuate the loss of muscle size and function with disuse or potentiate recovery but enhanced myofibrillar MPS during AR. NEW & NOTEWORTHY Twenty grams of daily protein supplementation does not attenuate the loss of muscle size and function induced by 2 wk of muscle disuse or potentiate recovery in middle-age men. Average mitochondrial but not myofibrillar muscle protein synthesis was attenuated during immobilization with no effect of supplementation. Protein supplementation increased myofibrillar protein synthesis during a 2-wk period of ambulatory recovery following disuse but without group differences in phenotype recovery.
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Affiliation(s)
| | - Randall F D'Souza
- Liggins Institute, The University of Auckland , Auckland , New Zealand
| | - Sarah M Mitchell
- Liggins Institute, The University of Auckland , Auckland , New Zealand
| | | | - Benjamin F Miller
- Department of Health and Exercise Science, Colorado State University , Fort Collins, Colorado
| | - Karyn L Hamilton
- Department of Health and Exercise Science, Colorado State University , Fort Collins, Colorado
| | - Fredrick F Peelor
- Department of Health and Exercise Science, Colorado State University , Fort Collins, Colorado
| | - Marcelli Coronet
- Liggins Institute, The University of Auckland , Auckland , New Zealand
| | - Chantal A Pileggi
- Liggins Institute, The University of Auckland , Auckland , New Zealand
| | | | - Aaron C Fanning
- Fonterra Research and Development Centre , Palmerston North , New Zealand
| | - Sally D Poppitt
- School of Biological Sciences, The University of Auckland , Auckland , New Zealand
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12
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Martini D, Biasini B, Rossi S, Zavaroni I, Bedogni G, Musci M, Pruneti C, Passeri G, Ventura M, Galli D, Mirandola P, Vitale M, Dei Cas A, Bonadonna RC, Del Rio D. Claimed effects, outcome variables and methods of measurement for health claims on foods proposed under European Community Regulation 1924/2006 in the area of appetite ratings and weight management. Int J Food Sci Nutr 2017; 69:389-409. [DOI: 10.1080/09637486.2017.1366433] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Daniela Martini
- Department of Food and Drugs, The Laboratory of Phytochemicals in Physiology, University of Parma, Parma, Italy
| | - Beatrice Biasini
- Department of Food and Drugs, The Laboratory of Phytochemicals in Physiology, University of Parma, Parma, Italy
| | - Stefano Rossi
- Department of Food and Drugs, The Laboratory of Phytochemicals in Physiology, University of Parma, Parma, Italy
| | - Ivana Zavaroni
- Department of Medicine and Surgery, Division of Endocrinology, University of Parma, Parma, Italy
- Azienda Ospedaliera Universitaria of Parma, Parma, Italy
| | - Giorgio Bedogni
- Clinical Epidemiology Unit, Liver Research Center, Trieste, Italy
| | - Marilena Musci
- Department of Food and Drugs, University of Parma, Parma, Italy
| | - Carlo Pruneti
- Department of Medicine and Surgery, Clinical Psychology Unit, University of Parma, Parma, Italy
| | - Giovanni Passeri
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Marco Ventura
- Department of Chemistry, Life Sciences and Environmental Sustainability, Laboratory of Probiogenomics, University of Parma, Parma, Italy
| | - Daniela Galli
- Department of Medicine and Surgery, Sport and Exercise Medicine Centre (SEM), University of Parma, Parma, Italy
| | - Prisco Mirandola
- Department of Medicine and Surgery, Sport and Exercise Medicine Centre (SEM), University of Parma, Parma, Italy
| | - Marco Vitale
- Department of Medicine and Surgery, Sport and Exercise Medicine Centre (SEM), University of Parma, Parma, Italy
| | - Alessandra Dei Cas
- Department of Medicine and Surgery, Division of Endocrinology, University of Parma, Parma, Italy
- Azienda Ospedaliera Universitaria of Parma, Parma, Italy
| | - Riccardo C. Bonadonna
- Department of Medicine and Surgery, Division of Endocrinology, University of Parma, Parma, Italy
- Azienda Ospedaliera Universitaria of Parma, Parma, Italy
| | - Daniele Del Rio
- Department of Food and Drugs, The Laboratory of Phytochemicals in Physiology, University of Parma, Parma, Italy
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13
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Robinson MM, Dasari S, Karakelides H, Bergen HR, Nair KS. Release of skeletal muscle peptide fragments identifies individual proteins degraded during insulin deprivation in type 1 diabetic humans and mice. Am J Physiol Endocrinol Metab 2016; 311:E628-37. [PMID: 27436610 PMCID: PMC5142007 DOI: 10.1152/ajpendo.00175.2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 07/13/2016] [Indexed: 12/16/2022]
Abstract
Insulin regulates skeletal muscle protein degradation, but the types of proteins being degraded in vivo remain to be determined due to methodological limitations. We present a method to assess the types of skeletal muscle proteins that are degraded by extracting their degradation products as low-molecular weight (LMW) peptides from muscle samples. High-resolution mass spectrometry was used to identify the original intact proteins that generated the LMW peptides, which we validated in rodents and then applied to humans. We deprived insulin from insulin-treated streptozotocin (STZ) diabetic mice for 6 and 96 h and for 8 h in type 1 diabetic humans (T1D) for comparison with insulin-treated conditions. Protein degradation was measured using activation of autophagy and proteasome pathways, stable isotope tracers, and LMW approaches. In mice, insulin deprivation activated proteasome pathways and autophagy in muscle homogenates and isolated mitochondria. Reproducibility analysis of LMW extracts revealed that ∼80% of proteins were detected consistently. As expected, insulin deprivation increased whole body protein turnover in T1D. Individual protein degradation increased with insulin deprivation, including those involved in mitochondrial function, proteome homeostasis, nDNA support, and contractile/cytoskeleton. Individual mitochondrial proteins that generated more LMW fragment with insulin deprivation included ATP synthase subunit-γ (+0.5-fold, P = 0.007) and cytochrome c oxidase subunit 6 (+0.305-fold, P = 0.03). In conclusion, identifying LMW peptide fragments offers an approach to determine the degradation of individual proteins. Insulin deprivation increases degradation of select proteins and provides insight into the regulatory role of insulin in maintaining proteome homeostasis, especially of mitochondria.
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Affiliation(s)
| | - Surendra Dasari
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota; and
| | | | - H Robert Bergen
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota
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14
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Anthony TG. Mechanisms of protein balance in skeletal muscle. Domest Anim Endocrinol 2016; 56 Suppl:S23-32. [PMID: 27345321 PMCID: PMC4926040 DOI: 10.1016/j.domaniend.2016.02.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 02/23/2016] [Accepted: 02/29/2016] [Indexed: 01/07/2023]
Abstract
Increased global demand for adequate protein nutrition against a backdrop of climate change and concern for animal agriculture sustainability necessitates new and more efficient approaches to livestock growth and production. Anabolic growth is achieved when rates of new synthesis exceed turnover, producing a positive net protein balance. Conversely, deterioration or atrophy of lean mass is a consequence of a net negative protein balance. During early life and periods of growth, muscle mass is driven by increases in protein synthesis at the level of mRNA translation. Throughout life, muscle mass is further influenced by degradative processes such as autophagy and the ubiquitin proteasome pathway. Multiple signal transduction networks guide and coordinate these processes alongside quality control mechanisms to maintain protein homeostasis (proteostasis). Genetics, hormones, and environmental stimuli each influence proteostasis control, altering capacity and/or efficiency of muscle growth. An overview of recent findings and current methods to assess muscle protein balance and proteostasis is presented. Current efforts to identify novel control points have the potential through selective breeding design or development of hormetic strategies to better promote growth and health span during environmental stress.
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Affiliation(s)
- T G Anthony
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ 08901, USA.
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15
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Pasiakos SM, Margolis LM, Orr JS. Optimized dietary strategies to protect skeletal muscle mass during periods of unavoidable energy deficit. FASEB J 2014; 29:1136-42. [DOI: 10.1096/fj.14-266890] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 12/01/2014] [Indexed: 12/14/2022]
Affiliation(s)
- Stefan M. Pasiakos
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Lee M. Margolis
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Jeb S. Orr
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
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16
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Pasiakos SM, Carbone JW. Assessment of skeletal muscle proteolysis and the regulatory response to nutrition and exercise. IUBMB Life 2014; 66:478-84. [PMID: 25052691 DOI: 10.1002/iub.1291] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 07/01/2014] [Indexed: 01/07/2023]
Abstract
Skeletal muscle proteolysis is highly regulated, involving complex intramuscular proteolytic systems that recognize and degrade muscle proteins, and recycle free amino acid precursors for protein synthesis and energy production. Autophagy-lysosomal, calpain, and caspase systems are contributors to muscle proteolysis, although the ubiquitin proteasome system (UPS) is the primary mechanism by which actomyosin fragments are degraded in healthy muscle. The UPS is sensitive to mechanical force and nutritional deprivation, as recent reports have demonstrated increased proteolytic gene expression and activity of the UPS in response to resistance and endurance exercise, and short-term negative energy balance. However, consuming dietary protein alone (or free amino acids), or as a primary component of a mixed meal, may attenuate intramuscular protein loss by down-regulating proteolytic gene expression and the catabolic activity of the UPS. Although these studies provide novel insight regarding the intramuscular regulation of skeletal muscle mass, the role of proteolysis in the regulation of skeletal muscle protein turnover in healthy human muscle is not well described. This article provides a contemporary review of the intramuscular regulation of skeletal muscle proteolysis in healthy muscle, methodological approaches to assess proteolysis, and highlights the effects of nutrition and exercise on skeletal muscle proteolysis.
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Affiliation(s)
- Stefan M Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
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17
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Reitelseder S, Agergaard J, Doessing S, Helmark IC, Schjerling P, van Hall G, Kjaer M, Holm L. Positive muscle protein net balance and differential regulation of atrogene expression after resistance exercise and milk protein supplementation. Eur J Nutr 2013; 53:321-33. [DOI: 10.1007/s00394-013-0530-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 04/21/2013] [Indexed: 11/24/2022]
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18
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Holm L, O'Rourke B, Ebenstein D, Toth MJ, Bechshoeft R, Holstein-Rathlou NH, Kjaer M, Matthews DE. Determination of steady-state protein breakdown rate in vivo by the disappearance of protein-bound tracer-labeled amino acids: a method applicable in humans. Am J Physiol Endocrinol Metab 2013; 304:E895-907. [PMID: 23423170 PMCID: PMC3625778 DOI: 10.1152/ajpendo.00579.2012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A method to determine the rate of protein breakdown in individual proteins was developed and tested in rats and confirmed in humans, using administration of deuterium oxide and incorporation of the deuterium into alanine that was subsequently incorporated into body proteins. Measurement of the fractional breakdown rate of proteins was determined from the rate of disappearance of deuterated alanine from the proteins. The rate of disappearance of deuterated alanine from the proteins was calculated using an exponential decay, giving the fractional breakdown rate (FBR) of the proteins. The applicability of this protein-specific FBR approach is suitable for human in vivo experimentation. The labeling period of deuterium oxide administration is dependent on the turnover rate of the protein of interest.
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Affiliation(s)
- Lars Holm
- Institute of Sports Medicine, Department of Orthopedic Surgery M81, Bispebjerg Hospital, and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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19
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Dideriksen K, Reitelseder S, Holm L. Influence of amino acids, dietary protein, and physical activity on muscle mass development in humans. Nutrients 2013; 5:852-76. [PMID: 23486194 PMCID: PMC3705323 DOI: 10.3390/nu5030852] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 02/13/2013] [Accepted: 02/25/2013] [Indexed: 12/14/2022] Open
Abstract
Ingestion of protein is crucial for maintenance of a variety of body functions and within the scope of this review we will specifically focus on the regulation of skeletal muscle mass. A quantitative limitation exists as to how much muscle protein the body can synthesize in response to protein intake. Ingestion of excess protein exerts an unwanted load to the body and therefore, it is important to find the least amount of protein that provides the maximal hypertrophic stimulus. Hence, research has focused on revealing the relationship between protein intake (dose) and its resulting stimulation of muscle protein synthesis (response). In addition to the protein amount, the protein digestibility and, hence, the availability of its constituent amino acids is decisive for the response. In this regard, recent studies have provided in-depth knowledge about the time-course of the muscle protein synthetic response dependent on the characteristics of the protein ingested. The effect of protein intake on muscle protein accretion can further be stimulated by prior exercise training. In the ageing population, physical training may counteract the development of “anabolic resistance” and restore the beneficial effect of protein feeding. Presently, our knowledge is based on measures obtained in standardized experimental settings or during long-term intervention periods. However, to improve coherence between these types of data and to further improve our knowledge of the effects of protein ingestion, other investigative approaches than those presently used are requested.
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Affiliation(s)
- Kasper Dideriksen
- Institute of Sports Medicine, Department of Orthopedic Surgery M81, Bispebjerg Hospital, Bispebjerg Bakke 23, DK-2400 Copenhagen NV, Denmark; E-Mails: (S.R.); (L.H.)
- Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +45-3531-3948; Fax: +45-3531-2733
| | - Søren Reitelseder
- Institute of Sports Medicine, Department of Orthopedic Surgery M81, Bispebjerg Hospital, Bispebjerg Bakke 23, DK-2400 Copenhagen NV, Denmark; E-Mails: (S.R.); (L.H.)
- Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Lars Holm
- Institute of Sports Medicine, Department of Orthopedic Surgery M81, Bispebjerg Hospital, Bispebjerg Bakke 23, DK-2400 Copenhagen NV, Denmark; E-Mails: (S.R.); (L.H.)
- Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
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