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Delescluse J, Simonnet MM, Ziegler AB, Piffaretti K, Alves G, Grosjean Y, Manière G. A LAT1-Like Amino Acid Transporter Regulates Neuronal Activity in the Drosophila Mushroom Bodies. Cells 2024; 13:1340. [PMID: 39195231 DOI: 10.3390/cells13161340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 07/25/2024] [Accepted: 07/26/2024] [Indexed: 08/29/2024] Open
Abstract
The proper functioning of neural circuits that integrate sensory signals is essential for individual adaptation to an ever-changing environment. Many molecules can modulate neuronal activity, including neurotransmitters, receptors, and even amino acids. Here, we ask whether amino acid transporters expressed by neurons can influence neuronal activity. We found that minidiscs (mnd), which encodes a light chain of a heterodimeric amino acid transporter, is expressed in different cell types of the adult Drosophila brain: in mushroom body neurons (MBs) and in glial cells. Using live calcium imaging, we found that MND expressed in α/β MB neurons is essential for sensitivity to the L-amino acids: Leu, Ile, Asp, Glu, Lys, Thr, and Arg. We found that the Target Of Rapamycin (TOR) pathway but not the Glutamate Dehydrogenase (GDH) pathway is involved in the Leucine-dependent response of α/β MB neurons. This study strongly supports the key role of MND in regulating MB activity in response to amino acids.
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Affiliation(s)
- Julie Delescluse
- Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAe, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
| | - Mégane M Simonnet
- Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAe, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
| | - Anna B Ziegler
- Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAe, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
- Institute for Neuro- and Behavioral Biology, University of Münster, 48149 Münster, Germany
| | - Kévin Piffaretti
- Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAe, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
| | - Georges Alves
- Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAe, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
| | - Yael Grosjean
- Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAe, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
| | - Gérard Manière
- Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAe, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
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Hanigan MD, Souza VC, Martineau R, Lapierre H, Feng X, Daley VL. A meta-analysis of the relationship between milk protein production and absorbed amino acids and digested energy in dairy cattle. J Dairy Sci 2024; 107:5587-5615. [PMID: 38490550 DOI: 10.3168/jds.2024-24230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 02/09/2024] [Indexed: 03/17/2024]
Abstract
Milk protein production is the largest draw on AA supplies for lactating dairy cattle. Prior NRC predictions of milk protein production have been absorbed protein (MP)-based and used a first-limiting nutrient concept to integrate the effects of energy and protein, which yielded poor accuracy and precision (root mean squared error [RMSE] >21%). Using a meta-data set gathered, various alternative equation forms considering MP, absorbed total EAA, absorbed individual EAA, and digested energy (DE) supplies as additive drivers of production were evaluated, and all were found to be superior in statistical performance to the first limitation approach (RMSE = 14%-15%). Inclusion of DE intake and a quadratic term for MP or absorbed EAA supplies were found to be necessary to achieve intercept estimates (nonproductive protein use) that were similar to the factorial estimates of the National Academies of Sciences, Engineering, and Medicine (2021). The partial linear slope for MP was found to be 0.409, which is consistent with the observed slope bias of -0.34 g/g when a slope of 0.67 was used for MP efficiency in a first-limiting nutrient system. Replacement of MP with the supplies of individual absorbed EAA expressed in grams per day and a common quadratic across the EAA resulted in unbiased predictions with improved statistical performance as compared with MP-based models. Based on Akaike's information criterion and biological consistency, the best equations included absorbed His, Ile, Lys, Met, Thr, the NEAA, and individual DE intakes from fatty acids, NDF, residual OM, and starch. Several also contained a term for absorbed Leu. These equations generally had RMSE of 14.3% and a concordance correlation of 0.76. Based on the common quadratic and individual linear terms, milk protein response plateaus were predicted at approximately 320 g/d of absorbed His, Ile, and Lys; 395 g/d of absorbed Thr; 550 g/d of absorbed Met; and 70 g/d of absorbed Leu. Therefore, responses to each except Leu are almost linear throughout the normal in vivo range. De-aggregation of the quadratic term and parsing to individual absorbed EAA resulted in nonbiological estimates for several EAA indicating over-parameterization. Expression of the EAA as g/100 g total absorbed EAA or as ratios of DE intake and using linear and quadratic terms for each EAA resulted in similar statistical performance, but the solutions had identifiability problems and several nonbiological parameter estimates. The use of ratios also introduced nonlinearity in the independent variables which violates linear regression assumptions. Further screening of the global model using absorbed EAA expressed as grams per day with a common quadratic using an all-models approach, and exhaustive cross-evaluation indicated the parameter estimates for BW, all 4 DE terms, His, Ile, Lys, Met, and the common quadratic term were stable, whereas estimates for Leu and Thr were known with less certainty. Use of independent and additive terms and a quadratic expression in the equation results in variable efficiencies of conversion. The additivity also provides partial substitution among the nutrients. Both of these prevent establishment of fixed nutrient requirements in support of milk protein production.
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Affiliation(s)
- M D Hanigan
- Department of Dairy Science, Virginia Tech, Blacksburg, VA 24061.
| | - V C Souza
- Department of Dairy Science, Virginia Tech, Blacksburg, VA 24061
| | - R Martineau
- Agriculture and Agri-Food Canada, Sherbrooke, QC, Canada J1M 0C8
| | - H Lapierre
- Agriculture and Agri-Food Canada, Sherbrooke, QC, Canada J1M 0C8
| | - X Feng
- Department of Dairy Science, Virginia Tech, Blacksburg, VA 24061
| | - V L Daley
- Department of Dairy Science, Virginia Tech, Blacksburg, VA 24061
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Yang Y, Wang S, Sheng C, Tan J, Chen J, Li T, Ma X, Sun H, Wang X, Zhou L. Branched-chain amino acid catabolic defect promotes α-cell proliferation via activating mTOR signaling. Mol Cell Endocrinol 2024; 582:112143. [PMID: 38158148 DOI: 10.1016/j.mce.2023.112143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/09/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
Elevated circulating level of branched-chain amino acids (BCAAs) is closely related to the development of type 2 diabetes. However, the role of BCAA catabolism in various tissues in maintaining glucose homeostasis remains largely unknown. Pancreatic α-cells have been regarded as amino acid sensors in recent years. Therefore, we generated α-cell specific branched-chain alpha-ketoacid dehydrogenase E1α subunit (BCKDHA) knockout (BCKDHA-αKO) mice to decipher the effects of BCAA catabolism in α-cells on whole-body energy metabolism. BCKDHA-αKO mice showed normal body weight, body fat, and energy expenditure. Plasma glucagon level and glucose metabolism also remained unchanged in BCKDHA-αKO mice. Whereas, the deletion of BCKDHA led to increased α-cell number due to elevated cell proliferation in neonatal mice. In vitro, only leucine among BCAAs promoted aTC1-6 cell proliferation, which was blocked by the agonist of BCAA catabolism BT2 and the inhibitor of mTOR Rapamycin. Like Rapamycin, BT2 attenuated leucine-stimulated phosphorylation of S6 in αTC1-6 cells. Elevated phosphorylation level of S6 protein in pancreatic α-cells was also observed in BCKDHA-αKO mice. These results suggest that local accumulated leucine due to defective BCAA catabolism promotes α-cell proliferation through mTOR signaling, which is insufficient to affect glucagon secretion and whole-body glucose homeostasis.
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Affiliation(s)
- Yulin Yang
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shushu Wang
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chunxiang Sheng
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jialin Tan
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Junmin Chen
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Tianjiao Li
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaoqin Ma
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Haipeng Sun
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Center for Cardiovascular Diseases, The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, 300134, China
| | - Xiao Wang
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Libin Zhou
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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Tamura K, Kitazawa H, Sugita S, Hashizume K, Iwashita M, Ishigami T, Minegishi Y, Shimotoyodome A, Ota N. Tyrosine Is a Booster of Leucine-Induced Muscle Anabolic Response. Nutrients 2023; 16:84. [PMID: 38201913 PMCID: PMC10780460 DOI: 10.3390/nu16010084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/14/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024] Open
Abstract
Leucine (Leu), an essential amino acid, is known to stimulate protein synthesis in the skeletal muscle via mTOR complex 1 (mTORC1) activation. However, the intrinsic contribution of other amino acids to Leu-mediated activation of mTORC1 signaling remains unexplored. This study aimed to identify amino acids that can promote mTORC1 activity in combination with Leu and to assess the effectiveness of these combinations in vitro and in vivo. We found that tyrosine (Tyr) enhanced Leu-induced phosphorylation of S6 kinase (S6K), an indicator of mTORC1 activity, although it exerted no such effect individually. This booster effect was observed in C2C12 cells, isolated murine muscle, and the skeletal muscles of mice orally administered the amino acids. To explore the molecular mechanisms underlying this Tyr-mediated booster effect, the expression of the intracellular Leu sensors, Sestrin1 and 2, was suppressed, and the cells were treated with Leu and Tyr. This suppression enabled Tyr alone to induce S6K phosphorylation and enhanced the booster effect, suggesting that Tyr possibly contributes to mTORC1 activation when Sestrin-GAP activity toward Rags 2 (GATOR2) is dissociated through Sestrin knockdown or the binding of Sestrins to Leu. Collectively, these results indicate that Tyr is a key regulator of Leu-mediated protein synthesis.
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Affiliation(s)
- Kotaro Tamura
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
| | - Hidefumi Kitazawa
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
| | - Satoshi Sugita
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
| | - Kohjiro Hashizume
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
| | - Masazumi Iwashita
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
| | - Takaaki Ishigami
- Processing Development Research, Kao Corporation, Wakayama-shi, Wakayama 640-8580, Japan
| | - Yoshihiko Minegishi
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
| | - Akira Shimotoyodome
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
| | - Noriyasu Ota
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
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5
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Marom R, Zhang B, Washington ME, Song IW, Burrage LC, Rossi VC, Berrier AS, Lindsey A, Lesinski J, Nonet ML, Chen J, Baldridge D, Silverman GA, Sutton VR, Rosenfeld JA, Tran AA, Hicks MJ, Murdock DR, Dai H, Weis M, Jhangiani SN, Muzny DM, Gibbs RA, Caswell R, Pottinger C, Cilliers D, Stals K, Eyre D, Krakow D, Schedl T, Pak SC, Lee BH. Dominant negative variants in KIF5B cause osteogenesis imperfecta via down regulation of mTOR signaling. PLoS Genet 2023; 19:e1011005. [PMID: 37934770 PMCID: PMC10656020 DOI: 10.1371/journal.pgen.1011005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 11/17/2023] [Accepted: 10/03/2023] [Indexed: 11/09/2023] Open
Abstract
BACKGROUND Kinesin motor proteins transport intracellular cargo, including mRNA, proteins, and organelles. Pathogenic variants in kinesin-related genes have been implicated in neurodevelopmental disorders and skeletal dysplasias. We identified de novo, heterozygous variants in KIF5B, encoding a kinesin-1 subunit, in four individuals with osteogenesis imperfecta. The variants cluster within the highly conserved kinesin motor domain and are predicted to interfere with nucleotide binding, although the mechanistic consequences on cell signaling and function are unknown. METHODS To understand the in vivo genetic mechanism of KIF5B variants, we modeled the p.Thr87Ile variant that was found in two patients in the C. elegans ortholog, unc-116, at the corresponding position (Thr90Ile) by CRISPR/Cas9 editing and performed functional analysis. Next, we studied the cellular and molecular consequences of the recurrent p.Thr87Ile variant by microscopy, RNA and protein analysis in NIH3T3 cells, primary human fibroblasts and bone biopsy. RESULTS C. elegans heterozygous for the unc-116 Thr90Ile variant displayed abnormal body length and motility phenotypes that were suppressed by additional copies of the wild type allele, consistent with a dominant negative mechanism. Time-lapse imaging of GFP-tagged mitochondria showed defective mitochondria transport in unc-116 Thr90Ile neurons providing strong evidence for disrupted kinesin motor function. Microscopy studies in human cells showed dilated endoplasmic reticulum, multiple intracellular vacuoles, and abnormal distribution of the Golgi complex, supporting an intracellular trafficking defect. RNA sequencing, proteomic analysis, and bone immunohistochemistry demonstrated down regulation of the mTOR signaling pathway that was partially rescued with leucine supplementation in patient cells. CONCLUSION We report dominant negative variants in the KIF5B kinesin motor domain in individuals with osteogenesis imperfecta. This study expands the spectrum of kinesin-related disorders and identifies dysregulated signaling targets for KIF5B in skeletal development.
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Affiliation(s)
- Ronit Marom
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Texas Children’s Hospital, Houston, Texas, United States of America
| | - Bo Zhang
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Megan E. Washington
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - I-Wen Song
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Lindsay C. Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Texas Children’s Hospital, Houston, Texas, United States of America
| | - Vittoria C. Rossi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Texas Children’s Hospital, Houston, Texas, United States of America
| | - Ava S. Berrier
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Anika Lindsey
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Jacob Lesinski
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Michael L. Nonet
- Department of Neuroscience, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Jian Chen
- Department of Genetics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Dustin Baldridge
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Gary A. Silverman
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - V. Reid Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Texas Children’s Hospital, Houston, Texas, United States of America
| | - Jill A. Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Alyssa A. Tran
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - M. John Hicks
- Texas Children’s Hospital, Houston, Texas, United States of America
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas, United States of America
| | - David R. Murdock
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Hongzheng Dai
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - MaryAnn Weis
- Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, Washington, United States of America
| | - Shalini N. Jhangiani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Donna M. Muzny
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Richard A. Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Richard Caswell
- Exeter Genomics Laboratory, Royal Devon University Healthcare NHS Foundation Trust, Exeter, United Kingdom
| | - Carrie Pottinger
- All Wales Medical Genomics Service, Wrexham Maelor Hospital, Wrexham, UK
| | - Deirdre Cilliers
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Karen Stals
- Exeter Genomics Laboratory, Royal Devon University Healthcare NHS Foundation Trust, Exeter, United Kingdom
| | | | - David Eyre
- Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, Washington, United States of America
| | - Deborah Krakow
- Human Genetics, Obstetrics & Gynecology, Orthopedic Surgery, University of California, Los Angeles, California, United States of America
| | - Tim Schedl
- Department of Genetics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Stephen C. Pak
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Brendan H. Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Texas Children’s Hospital, Houston, Texas, United States of America
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Hiol AN, von Hurst PR, Conlon CA, Beck KL. Associations of protein intake, sources and distribution on muscle strength in community-dwelling older adults living in Auckland, New Zealand. J Nutr Sci 2023; 12:e94. [PMID: 37649694 PMCID: PMC10465299 DOI: 10.1017/jns.2023.76] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 07/12/2023] [Accepted: 07/17/2023] [Indexed: 09/01/2023] Open
Abstract
Protein intake, sources and distribution impact on muscle protein synthesis and muscle mass in older adults. However, it is less clear whether dietary protein influences muscle strength. Data were obtained from the Researching Eating Activity and Cognitive Health (REACH) study, a cross-sectional study aimed at investigating dietary patterns, cognitive function and metabolic syndrome in older adults aged 65-74 years. Dietary intake was assessed using a 4-d food record and muscle strength using a handgrip strength dynamometer. After adjusting for confounders, in female older adults (n 212), total protein intake (β = 0⋅22, P < 0⋅01); protein from dairy and eggs (β = 0⋅21, P = 0⋅03) and plant food sources (β = 0⋅60, P < 0⋅01); and frequently consuming at least 0⋅4 g/kg BW per meal (β = 0⋅08, P < 0⋅01) were associated with higher BMI-adjusted muscle strength. However, protein from meat and fish intake and the coefficient of variance of protein intake were not related to BMI-muscle strength in female older adults. No statistically significant associations were observed in male participants (n = 113). There may be sex differences when investigating associations between protein intake and muscle strength in older adults. Further research is needed to investigate these sex differences.
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Affiliation(s)
- Anne N. Hiol
- School of Sport, Exercise and Nutrition, Massey University, North Shore City 0632, New Zealand
| | - Pamela R. von Hurst
- School of Sport, Exercise and Nutrition, Massey University, North Shore City 0632, New Zealand
| | - Cathryn A. Conlon
- School of Sport, Exercise and Nutrition, Massey University, North Shore City 0632, New Zealand
| | - Kathryn L. Beck
- School of Sport, Exercise and Nutrition, Massey University, North Shore City 0632, New Zealand
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7
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Forester SM, Jennings-Dobbs EM, Sathar SA, Layman DK. Perspective: Developing a Nutrient-Based Framework for Protein Quality. J Nutr 2023; 153:2137-2146. [PMID: 37301285 DOI: 10.1016/j.tjnut.2023.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 05/09/2023] [Accepted: 06/06/2023] [Indexed: 06/12/2023] Open
Abstract
The future of precision nutrition requires treating amino acids as essential nutrients. Currently, recognition of essential amino acid requirements is embedded within a generalized measure of protein quality known as the PDCAAS (Protein Digestibility-Corrected Amino Acid Score). Calculating the PDCAAS includes the FAO/WHO/UNU amino acid score, which is based on the limiting amino acid in a food, that is, the single amino acid with the lowest concentration compared to the reference standard. That "limiting" amino acid score is then multiplied by a bioavailability factor to obtain the PDCAAS, which ranks proteins from 0.0 (poor quality) to 1.0 (high quality). However, the PDCAAS has multiple limitations: it only allows for direct protein quality comparison between 2 proteins, and it is not scalable, transparent, or additive. We therefore propose that shifting the protein quality evaluation paradigm from the current generalized perspective to a precision nutrition focus treating amino acids as unique, metabolically active nutrients will be valuable for multiple areas of science and public health. We report the development and validation of the Essential Amino Acid 9 (EAA-9) score, an innovative, nutrient-based protein quality scoring framework. EAA-9 scores can be used to ensure that dietary recommendations for each essential amino acid are met. The EAA-9 scoring framework also offers the advantages of being additive and, perhaps most importantly, allows for personalization of essential amino acid needs based on age or metabolic conditions. Comparisons of the EAA-9 score with PDCAAS demonstrated the validity of the EAA-9 framework, and practical applications demonstrated that the EAA-9 framework is a powerful tool for precision nutrition applications.
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Affiliation(s)
| | | | | | - Donald K Layman
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL
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8
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Soleimani E, Abbasalizad Farhangi M. Protein Quality, Glycemic and Metabolic Indices and Anthropometric Features Among Overweight and Obese Adults. Nutr Metab Insights 2023; 16:11786388231181038. [PMID: 37435042 PMCID: PMC10331230 DOI: 10.1177/11786388231181038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 05/22/2023] [Indexed: 07/13/2023] Open
Abstract
Background Various studies have shown an inverse relationship between the quality of protein intake based on essential amino acids (EAAs) with obesity and its complications. We assumed that increasing EAAs-based protein intake quality improves glycemic and metabolic markers and anthropometric measurements in obese and overweight people. Methods This cross-sectional study included 180 obese and overweight participants aged 18 to 35. Dietary information was obtained using an 80-item food frequency questionnaire. The total intake of EAAs was calculated using the United States department of agriculture (USDA) database. Quality protein was defined as the ratio of EAAs (gr) to total dietary protein (gr). Sociodemographic status, physical activity (PA), and anthropometric characteristics were evaluated using a valid and reliable method. Analysis of covariance (ANCOVA) tests adjusted for sex, PA, age, energy, and body mass index (BMI) were used to measure this association. Results Protein quality intake was highest among the group with the lowest weight, body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), and fat mass (FM); and on the other hand, the fat-free mass (FFM) has increased; also Increasing the quality of protein intake improved the lipid profile and some glycemic indices and insulin sensitivity, although this association was not significant. Conclusions Increasing the quality of protein intake significantly improved anthropometric measurements, and also improved some glycemic and metabolic indices although, their relationship was not significant.
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Affiliation(s)
- Ensiye Soleimani
- Tabriz Health Services Management Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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Higher Intake of Total Dietary Essential Amino Acids Is Associated with a Lower Prevalence of Metabolic Syndrome among Korean Adults. Nutrients 2022; 14:nu14224771. [PMID: 36432458 PMCID: PMC9694173 DOI: 10.3390/nu14224771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 11/16/2022] Open
Abstract
We hypothesized that a well-balanced intake of total essential amino acids (EAAs) may be associated with lower prevalence of metabolic syndrome among Korean adults. This population-based cross-sectional study included 25,787 participants aged ≥30 years from the 2008-2019 Korea National Health and Nutrition Examination Survey. Dietary information was obtained from 24 h recall data. Demographic and lifestyle factors were assessed using self-administered questionnaires, and metabolic biomarkers were obtained from a health examination. Total essential amino acid score (EAAS) was calculated to determine whether essential amino acid (EAA) intake meets the recommended nutrient intake (RNI). Multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression models. After adjusting for multiple confounding factors, participants with higher EAAS had a significantly lower prevalence of high blood pressure (OR: 0.86, 95% CI: 0.75-0.98), hypertriglyceridemia (OR: 0.86, 95% CI: 0.76-0.98), and Metabolic syndrome (MetS) (OR: 0.86, 95% CI: 0.74-0.996). Spline regression analysis confirmed linearity of the association between total EAAS and MetS. EAA intake and MetS are associated with an inverse dose-response relationship in which metabolic disease may be prevented when the overall EAA intake meets the RNI.
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NISHIKAWA A, NISHIKAWA A, KAMAJIRI N, OKADA K, IMAGITA H. The Effects of Branched-Chain Amino Acids on the Akt/mTOR Pathway and Nebulin Protein in Joint Fixation-Induced Muscle Atrophy. J Nutr Sci Vitaminol (Tokyo) 2022; 68:112-119. [DOI: 10.3177/jnsv.68.112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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11
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Robust LC3B lipidation analysis by precisely adjusting autophagic flux. Sci Rep 2022; 12:79. [PMID: 34996966 PMCID: PMC8742033 DOI: 10.1038/s41598-021-03875-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 12/06/2021] [Indexed: 12/20/2022] Open
Abstract
Autophagic flux can be quantified based on the accumulation of lipidated LC3B in the presence of late-stage autophagy inhibitors. This method has been widely applied to identify novel compounds that activate autophagy. Here we scrutinize this approach and show that bafilomycin A1 (BafA) but not chloroquine is suitable for flux quantification due to the stimulating effect of chloroquine on non-canonical LC3B-lipidation. Significant autophagic flux increase by rapamycin could only be observed when combining it with BafA concentrations not affecting basal flux, a condition which created a bottleneck, rather than fully blocking autophagosome-lysosome fusion, concomitant with autophagy stimulation. When rapamycin was combined with saturating concentrations of BafA, no significant further increase of LC3B lipidation could be detected over the levels induced by the late-stage inhibitor. The large assay window obtained by this approach enables an effective discrimination of autophagy activators based on their cellular potency. To demonstrate the validity of this approach, we show that a novel inhibitor of the acetyltransferase EP300 activates autophagy in a mTORC1-dependent manner. We propose that the creation of a sensitized background rather than a full block of autophagosome progression is required to quantitatively capture changes in autophagic flux.
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12
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Lee HL, Lee J, Cha JH, Cho S, Sung PS, Hur W, Yoon SK, Bae SH. Anti-fibrotic effects of branched-chain amino acids on hepatic stellate cells. Korean J Intern Med 2022; 37:53-62. [PMID: 32872742 PMCID: PMC8747913 DOI: 10.3904/kjim.2020.197] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/20/2020] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND/AIMS Patients with liver cirrhosis (LC) have low levels of branched-chain amino acids (BCAAs). There is accumulating evidence that BCAAs have anti- fibrotic effects in cirrhosis. This study is aimed to evaluate the effect of BCAAs on the function and phenotype of activated hepatic stellate cells (HSCs). METHODS LX-2, an immortalized human stellate cell line, was used in in vitro experiments. LX-2 cells were exposed to transforming growth factor β1 (TGF-β1) and BCAAs or to valine, leucine, and isoleucine, which are components of BCAAs. Activation of the TGF-β signaling pathway in LX-2 cells was observed using real-time quantitative polymerase chain reaction and Western blotting. RESULTS The increased expression of snail family transcriptional repressor 1 (SNAI1) was observed in LX-2 cells activated by TGF-β1. After BCAA treatment, its expression was significantly decreased at the mRNA level. The increased expression of Col1α1 and TIMP2 at the mRNA level and alpha smooth muscle actin at the protein level in activated LX-2 cells decreased after BCAA treatment. Among the BCAA components, leucine and valine significantly abrogated TGF-β-induced activation of LX-2 cells. BCAA treatment led to the decreased phosphorylation of Smad2 and p38 proteins, which are markers for Smad and Smad-independent p38 mitogen-activated protein kinase signaling pathways, respectively. CONCLUSION BCAA treatment can improve hepatic fibrosis by directly affecting the activated state of hepatic stellate cells through inhibition of the TGF-β signaling pathway. Among BCAA components, leucine and valine mainly abrogated TGF-β-induced activation of HSCs. Our results suggest that BCAA may be used to attenuate the progression of liver fibrosis.
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Affiliation(s)
- Hae Lim Lee
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
- The Catholic University Liver Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jungmin Lee
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jung Hoon Cha
- The Catholic University Liver Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Korea
| | - Sungwoo Cho
- The Catholic University Liver Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Korea
| | - Pil Soo Sung
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
- The Catholic University Liver Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Wonhee Hur
- The Catholic University Liver Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Seung Kew Yoon
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
- The Catholic University Liver Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Si Hyun Bae
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
- The Catholic University Liver Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Korea
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13
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Zhang S, Lin X, Hou Q, Hu Z, Wang Y, Wang Z. Regulation of mTORC1 by amino acids in mammalian cells: A general picture of recent advances. ACTA ACUST UNITED AC 2021; 7:1009-1023. [PMID: 34738031 PMCID: PMC8536509 DOI: 10.1016/j.aninu.2021.05.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 05/13/2021] [Accepted: 05/18/2021] [Indexed: 12/11/2022]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) integrates various types of signal inputs, such as energy, growth factors, and amino acids to regulate cell growth and proliferation mainly through the 2 direct downstream targets, eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1) and ribosomal protein S6 kinase 1 (S6K1). Most of the signal arms upstream of mTORC1 including energy status, stress signals, and growth factors converge on the tuberous sclerosis complex (TSC) - Ras homologue enriched in brain (Rheb) axis. Amino acids, however, are distinct from other signals and modulate mTORC1 using a unique pathway. In recent years, the transmission mechanism of amino acid signals upstream of mTORC1 has been gradually elucidated, and some sensors or signal transmission pathways for individual amino acids have also been discovered. With the help of these findings, we propose a general picture of recent advances, which demonstrates that various amino acids from lysosomes, cytoplasm, and Golgi are sensed by their respective sensors. These signals converge on mTORC1 and form a huge and complicated signal network with multiple synergies, antagonisms, and feedback mechanisms.
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Affiliation(s)
- Shizhe Zhang
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Xueyan Lin
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Qiuling Hou
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Zhiyong Hu
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Yun Wang
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Zhonghua Wang
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
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14
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Uddin GM, Karwi QG, Pherwani S, Gopal K, Wagg CS, Biswas D, Atnasious M, Wu Y, Wu G, Zhang L, Ho KL, Pulinilkunnil T, Ussher JR, Lopaschuk GD. Deletion of BCATm increases insulin-stimulated glucose oxidation in the heart. Metabolism 2021; 124:154871. [PMID: 34478752 DOI: 10.1016/j.metabol.2021.154871] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 08/21/2021] [Accepted: 08/27/2021] [Indexed: 02/01/2023]
Abstract
BACKGROUNDS Branched chain amino acid (BCAA) oxidation is impaired in cardiac insulin resistance, leading to the accumulation of BCAAs and the first products of BCAA oxidation, the branched chain ketoacids. However, it is not clear whether it is the BCAAs, BCKAs or both that are mediating cardiac insulin resistance. To determine this, we produced mice with a cardiac-specific deletion of BCAA aminotransferase (BCATm-/-), the first enzyme in the BCAA oxidation pathway that is responsible for converting BCAAs to BCKAs. METHODS Eight-week-old BCATm cardiac specific knockout (BCATm-/-) male mice and their α-MHC (myosin heavy chain) - Cre expressing wild type littermates (WT-Cre+/+) received tamoxifen (50 mg/kg i.p. 6 times over 8 days). At 16-weeks of age, cardiac energy metabolism was assessed in isolated working hearts. RESULTS BCATm-/- mice have decreased cardiac BCAA oxidation rates, increased cardiac BCAAs and a reduction in cardiac BCKAs. Hearts from BCATm-/- mice showed an increase in insulin stimulation of glucose oxidation and an increase in p-AKT. To determine the impact of reversing these events, we perfused isolated working mice hearts with high levels of BCKAs, which completely abolished insulin-stimulated glucose oxidation rates, an effect associated with decreased p-AKT and inactivation of pyruvate dehydrogenase (PDH), the rate-limiting enzyme in glucose oxidation. CONCLUSION This implicates the BCKAs, and not BCAAs, as the actual mediators of cardiac insulin resistance and suggests that lowering cardiac BCKAs can be used as a therapeutic strategy to improve insulin sensitivity in the heart.
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Affiliation(s)
- Golam M Uddin
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Qutuba G Karwi
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada; Department of Pharmacology, College of Medicine, University of Diyala, Diyala, Iraq
| | - Simran Pherwani
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Keshav Gopal
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, Canada; Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
| | - Cory S Wagg
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Dipsikha Biswas
- Department of Biochemistry Molecular Biology, Dalhousie University, Canada
| | - Mariam Atnasious
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Yikuan Wu
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Guoqing Wu
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada; State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, PR China
| | - Liyan Zhang
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Kim L Ho
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | | | - John R Ussher
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, Canada; Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
| | - Gary D Lopaschuk
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada; Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, Canada.
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15
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Newton-Tanzer E, Demmelmair H, Horak J, Holdt L, Koletzko B, Grote V. Acute Metabolic Response in Adults to Toddler Milk Formulas with Alternating Higher and Lower Protein and Fat Contents, a Randomized Cross-Over Trial. Nutrients 2021; 13:nu13093022. [PMID: 34578900 PMCID: PMC8472683 DOI: 10.3390/nu13093022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 08/24/2021] [Accepted: 08/27/2021] [Indexed: 01/23/2023] Open
Abstract
Protein intake in early life influences metabolism, weight gain, and later obesity risk. As such, a better understanding of the effects of protein intake on the postprandial metabolism and its dynamics over time may elucidate underlying mechanisms. In a randomized crossover study, we observed fasted adults who consumed two isocaloric toddler milk formulas concentrated as meals of 480 kcal with 67 g of carbohydrates 30 g (HP) or 7 g (LP) protein, and 10 g or 20 g fat, respectively. Anthropometry and body plethysmography were assessed, and blood samples collected at baseline and over five hours. Time-specific concentrations, areas under concentration curves (AUC), and maximum values of metabolites were compared by paired t-tests to examine the effects of protein content of toddler milks on postprandial plasma concentrations of insulin, glucose, branched-chain amino acids (BCAA), urea and triglycerides. Twenty-seven men and women aged 26.7 ± 5.0 years (BMI: 22.2 ± 2.5 kg/m2) (mean ± SD) participated. BCAA AUC, and Cmax values were significantly higher with HP than LP (144,765 ± 21,221 vs. 97,089 ± 14,650 µmol·min/L, p < 0.001; 656 ± 120 vs. 407 ± 66 µmol/L, p < 0.001), as were insulin AUC and Cmax values (6674 ± 3013 vs. 5600 ± 2423 µmol·min/L, p = 0.005; 71 ± 37 vs. 55 ± 28 µmol/L, p = 0.001). Higher glucose, urea, and triglyceride concentrations occurred in the late postprandial phase (≥180 min) with HP. In conclusion, we noted that higher milk protein intake induces increased postprandial BCAA concentrations for at least 5 h and led to higher initial insulin secretion. Gluconeogenesis due to an influx of amino acids and their degradation after HP meal might explain the late effects of protein intake on glucose and insulin.
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Affiliation(s)
- Emily Newton-Tanzer
- Division of Metabolic and Nutritional Medicine, Dr. von Hauner Children’s Hospital, LMU University Hospital Munich, 80337 Munich, Germany; (E.N.-T.); (H.D.); (J.H.); (V.G.)
| | - Hans Demmelmair
- Division of Metabolic and Nutritional Medicine, Dr. von Hauner Children’s Hospital, LMU University Hospital Munich, 80337 Munich, Germany; (E.N.-T.); (H.D.); (J.H.); (V.G.)
| | - Jeannie Horak
- Division of Metabolic and Nutritional Medicine, Dr. von Hauner Children’s Hospital, LMU University Hospital Munich, 80337 Munich, Germany; (E.N.-T.); (H.D.); (J.H.); (V.G.)
| | - Lesca Holdt
- Institute of Laboratory Medicine, LMU University Hospital Munich, 81377 Munich, Germany;
| | - Berthold Koletzko
- Division of Metabolic and Nutritional Medicine, Dr. von Hauner Children’s Hospital, LMU University Hospital Munich, 80337 Munich, Germany; (E.N.-T.); (H.D.); (J.H.); (V.G.)
- Correspondence: ; Tel.: +49-(0)89-4400-52826
| | - Veit Grote
- Division of Metabolic and Nutritional Medicine, Dr. von Hauner Children’s Hospital, LMU University Hospital Munich, 80337 Munich, Germany; (E.N.-T.); (H.D.); (J.H.); (V.G.)
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16
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SAR1B senses leucine levels to regulate mTORC1 signalling. Nature 2021; 596:281-284. [PMID: 34290409 DOI: 10.1038/s41586-021-03768-w] [Citation(s) in RCA: 82] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 06/24/2021] [Indexed: 01/13/2023]
Abstract
The mTOR complex 1 (mTORC1) controls cell growth in response to amino acid levels1. Here we report SAR1B as a leucine sensor that regulates mTORC1 signalling in response to intracellular levels of leucine. Under conditions of leucine deficiency, SAR1B inhibits mTORC1 by physically targeting its activator GATOR2. In conditions of leucine sufficiency, SAR1B binds to leucine, undergoes a conformational change and dissociates from GATOR2, which results in mTORC1 activation. SAR1B-GATOR2-mTORC1 signalling is conserved in nematodes and has a role in the regulation of lifespan. Bioinformatic analysis reveals that SAR1B deficiency correlates with the development of lung cancer. The silencing of SAR1B and its paralogue SAR1A promotes mTORC1-dependent growth of lung tumours in mice. Our results reveal that SAR1B is a conserved leucine sensor that has a potential role in the development of lung cancer.
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Sun S, He D, Luo C, Lin X, Wu J, Yin X, Jia C, Pan Q, Dong X, Zheng F, Li H, Zhou J. Metabolic Syndrome and Its Components Are Associated With Altered Amino Acid Profile in Chinese Han Population. Front Endocrinol (Lausanne) 2021; 12:795044. [PMID: 35058883 PMCID: PMC8765338 DOI: 10.3389/fendo.2021.795044] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/08/2021] [Indexed: 02/01/2023] Open
Abstract
OBJECTIVE Recent studies have found that the levels of plasma amino acids, such as branched-chain amino acids and aromatic amino acids, were associated with visceral obesity, insulin resistance, future development of diabetes and cardiovascular diseases. However, few studies have involved a Chinese Han population. This study aimed to examine the association between amino acid profile and metabolic syndrome (MetS) and its components in the Chinese Han population. METHODS This is a cross-sectional study, which enrolled a cohort of 473 participants from a community. We employed the isotope internal standard method to determine the plasma concentrations of 28 amino acids using high-performance liquid chromatography-tandem mass spectrometry (LC/MS). Participants were divided into MetS (n = 72) and non-MetS groups (n = 401) to analyze the association between amino acids and MetS and its components. RESULTS The prevalence of MetS was 15.2% according to the criteria. Plasma concentrations of isoleucine (Ile), leucine (Leu), valine (Val), tyrosine (Tyr), tryptophan (Trp), phenylalanine (Phe), glutamic acid (Glu), aspartic acid (Asp), alanine (Ala), histidine (His), methionine (Met), asparagine (Asn), and proline (Pro) were significantly higher in the MetS group than those in the non-MetS group (P < 0.05), but taurine (Tau) was significantly lower (P < 0.05). When MetS components were increased, the concentrations of these 13 amino acids significantly increased (P < 0.05), but Tau concentration was significantly decreased (P < 0.05). We extracted the amino acid profile by principal component analysis (PCA), PC1 and PC2, which extracted from the 14 amino acids, were significantly associated with MetS (odds ratio, 95% confidence interval: 1.723, 1.325-2.085 and 1.325, 1.043-1.684, respectively). A total of 260 non-MetS participants were followed up effectively, and 42 participants developed new-onset MetS within 5 years. We found that the amino acid profile of PC1 was linked to the occurrence of future MetS. Decreased Tau was correlated with the future development of MetS. CONCLUSION Participants with MetS exhibit an abnormal amino acid profile, and its components gradually increase when these amino acids are altered. Amino acid PCA profile can be employed for assessing and monitoring MetS risk. Finally, decreased Tau may be linked to the future development of MetS.
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Affiliation(s)
- Shuiya Sun
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Dongjuan He
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Department of Endocrinology, People’s Hospital of Quzhou, Quzhou, China
| | - Cheng Luo
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Department of Endocrinology, People’s Hospital of Quzhou, Quzhou, China
| | - Xihua Lin
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jiahua Wu
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xueyao Yin
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Chengfang Jia
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qianqian Pan
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xuehong Dong
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Fenping Zheng
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hong Li
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- *Correspondence: Jiaqiang Zhou, ; Hong Li,
| | - Jiaqiang Zhou
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- *Correspondence: Jiaqiang Zhou, ; Hong Li,
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18
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Biswas D, Dao KT, Mercer A, Cowie AM, Duffley L, El Hiani Y, Kienesberger PC, Pulinilkunnil T. Branched-chain ketoacid overload inhibits insulin action in the muscle. J Biol Chem 2020; 295:15597-15621. [PMID: 32878988 DOI: 10.1074/jbc.ra120.013121] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 08/29/2020] [Indexed: 12/18/2022] Open
Abstract
Branched-chain α-keto acids (BCKAs) are catabolites of branched-chain amino acids (BCAAs). Intracellular BCKAs are cleared by branched-chain ketoacid dehydrogenase (BCKDH), which is sensitive to inhibitory phosphorylation by BCKD kinase (BCKDK). Accumulation of BCKAs is an indicator of defective BCAA catabolism and has been correlated with glucose intolerance and cardiac dysfunction. However, it is unclear whether BCKAs directly alter insulin signaling and function in the skeletal and cardiac muscle cell. Furthermore, the role of excess fatty acids (FAs) in perturbing BCAA catabolism and BCKA availability merits investigation. By using immunoblotting and ultra-performance liquid chromatography MS/MS to analyze the hearts of fasted mice, we observed decreased BCAA-catabolizing enzyme expression and increased circulating BCKAs, but not BCAAs. In mice subjected to diet-induced obesity (DIO), we observed similar increases in circulating BCKAs with concomitant changes in BCAA-catabolizing enzyme expression only in the skeletal muscle. Effects of DIO were recapitulated by simulating lipotoxicity in skeletal muscle cells treated with saturated FA, palmitate. Exposure of muscle cells to high concentrations of BCKAs resulted in inhibition of insulin-induced AKT phosphorylation, decreased glucose uptake, and mitochondrial oxygen consumption. Altering intracellular clearance of BCKAs by genetic modulation of BCKDK and BCKDHA expression showed similar effects on AKT phosphorylation. BCKAs increased protein translation and mTORC1 activation. Pretreating cells with mTORC1 inhibitor rapamycin restored BCKA's effect on insulin-induced AKT phosphorylation. This study provides evidence for FA-mediated regulation of BCAA-catabolizing enzymes and BCKA content and highlights the biological role of BCKAs in regulating muscle insulin signaling and function.
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Affiliation(s)
- Dipsikha Biswas
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Khoi T Dao
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Angella Mercer
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Andrew M Cowie
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Luke Duffley
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Yassine El Hiani
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Petra C Kienesberger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Thomas Pulinilkunnil
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada.
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Chen S, Xia Y, He F, Fu J, Xin Z, Deng B, He L, Zhou X, Ren W. Serine Supports IL-1β Production in Macrophages Through mTOR Signaling. Front Immunol 2020; 11:1866. [PMID: 32973770 PMCID: PMC7481448 DOI: 10.3389/fimmu.2020.01866] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 07/13/2020] [Indexed: 12/13/2022] Open
Abstract
Intracellular metabolic programs tightly regulate the functions of macrophages, and previous studies have shown that serine mainly shapes the macrophage function via one-carbon metabolism. However, it is unknown whether serine modulates the macrophage function independent of one-carbon metabolism. Here, we find that serine deprivation lowers interleukin (IL)-1β production and inflammasome activation, as well as reprograms the transcriptomic and metabolic profile in M1 macrophages. Intriguingly, supplementation of formate, glycine, dNTPs, and glucose cannot rescue the production of IL-1β from serine-deprived macrophages. Mechanistically, serine deprivation inhibits macrophage IL-1β production through inhibition of mechanistic target of rapamycin (mTOR) signaling. Of note, the macrophages from mice feeding serine-free diet have lower IL-1β production, and these mice also show less inflammation after LPS challenge. Collectively, our data highlight a new regulatory mechanism for serine to modulate the macrophage function.
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Affiliation(s)
- Siyuan Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory of Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Yaoyao Xia
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory of Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Fang He
- College of Animal Science and Technology, Southwest University, Chongqing, China
| | - Jian Fu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory of Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Zhongquan Xin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory of Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Baichuan Deng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory of Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Liuqin He
- Hunan International Joint Laboratory of Animal Intestinal Ecology and Health, Laboratory of Animal Nutrition and Human Health, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Xihong Zhou
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China
| | - Wenkai Ren
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory of Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China
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Dietary valine levels affect growth, protein utilisation, immunity and antioxidant status in juvenile hybrid grouper ( Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂). Br J Nutr 2020; 125:408-419. [PMID: 32713354 DOI: 10.1017/s0007114520002858] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A 6-week growth trial was conducted to evaluate the influences of dietary valine (Val) levels on growth, protein utilisation, immunity, antioxidant status and gut micromorphology of juvenile hybrid groupers. Seven isoenergetic, isoproteic and isolipidic diets were formulated to contain graded Val levels (1·21, 1·32, 1·45, 1·58, 1·69, 1·82 and 1·94 %, DM basis). Each experimental diet was hand-fed to triplicate groups of twelve hybrid grouper juveniles. Results showed that weight gain percentage (WG%), protein productive value, protein efficiency ratio, and feed efficiency were increased as dietary Val level increased, reaching a peak value at 1·58 % dietary Val. The quadratic regression analysis of WG% against dietary Val levels indicated that the optimum dietary Val requirement for hybrid groupers was estimated to be 1·56 %. Gut micromorphology and expression of growth hormone in pituitary, insulin-like growth factor 1, target of rapamycin and S6 kinase 1 in liver were significantly affected by dietary Val levels. In serum, fish fed 1·58 % dietary Val had higher superoxide dismutase, catalase, lysozyme activities and IgM concentrations than fish fed other dietary Val levels. Fish fed 1·58 % dietary Val had higher expression of NF-E2-related factor 2 in head kidney than fish fed other dietary Val levels. Generally, the optimum dietary Val requirement for maximal growth of hybrid groupers was estimated to be 1·56 % of DM, corresponding to 3·16 % of dietary protein, and dietary Val levels affected growth, protein utilisation, immunity and antioxidant status in hybrid groupers.
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21
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Oparija-Rogenmozere L, Rajendran A, Poncet N, Camargo SMR, Verrey F. Phosphorylation of mouse intestinal basolateral amino acid uniporter LAT4 is controlled by food-entrained diurnal rhythm and dietary proteins. PLoS One 2020; 15:e0233863. [PMID: 32470053 PMCID: PMC7259769 DOI: 10.1371/journal.pone.0233863] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 05/13/2020] [Indexed: 12/29/2022] Open
Abstract
Adaptive regulation of epithelial transporters to nutrient intake is essential to decrease energy costs of their synthesis and maintenance, however such regulation is understudied. Previously we demonstrated that the transport function of the basolateral amino acid uniporter LAT4 (Slc43a2) is increased by dephosphorylation of serine 274 (S274) and nearly abolished by dephosphorylation of serine 297 (S297) when expressed in Xenopus oocytes. Phosphorylation changes in the jejunum of food-entrained mice suggested an increase in LAT4 transport function during food expectation. Thus, we investigated further how phosphorylation, expression and localization of mouse intestinal LAT4 respond to food-entrained diurnal rhythm and dietary protein content. In mice entrained with 18% protein diet, LAT4 mRNA was not submitted to diurnal regulation, unlike mRNAs of luminal symporters and antiporters. Only in duodenum, LAT4 protein expression increased during food intake. Concurrently, S274 phosphorylation was decreased in all three small intestinal segments, whereas S297 phosphorylation was increased only in jejunum. Interestingly, during food intake, S274 phosphorylation was nearly absent in ileum and accompanied by strong phosphorylation of mTORC1 target S6. Entraining mice with 8% protein diet provoked a shift in jejunal LAT4 localization from the cell surface to intracellular stores and increased S274 phosphorylation in both jejunum and ileum during food anticipation, suggesting decreased transport function. In contrast, 40% dietary protein content led to increased LAT4 expression in jejunum and its internalization in ileum. Ex vivo treatments of isolated intestinal villi fraction demonstrated that S274 phosphorylation was stimulated by protein kinase A. Rapamycin-sensitive insulin treatment and amino acids increased S297 phosphorylation, suggesting that the response to food intake might be regulated via the insulin-mTORC1 pathway. Ghrelin, an oscillating orexigenic hormone, did not affect phosphorylation of intestinal LAT4. Overall, we show that phosphorylation, expression and localization of intestinal mouse LAT4 responds to diurnal and dietary stimuli in location-specific manner.
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Affiliation(s)
- Lalita Oparija-Rogenmozere
- Institute of Physiology and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Anuradha Rajendran
- Institute of Physiology and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Nadège Poncet
- Institute of Physiology and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Simone M R Camargo
- Institute of Physiology and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - François Verrey
- Institute of Physiology and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland.,NCCR Kidney.CH, Zurich, Switzerland
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22
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Kawakami Y, Hambright WS, Takayama K, Mu X, Lu A, Cummins JH, Matsumoto T, Yurube T, Kuroda R, Kurosaka M, Fu FH, Robbins PD, Niedernhofer LJ, Huard J. Rapamycin Rescues Age-Related Changes in Muscle-Derived Stem/Progenitor Cells from Progeroid Mice. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 14:64-76. [PMID: 31312666 PMCID: PMC6610712 DOI: 10.1016/j.omtm.2019.05.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 05/14/2019] [Indexed: 12/13/2022]
Abstract
Aging-related loss of adult stem cell function contributes to impaired tissue regeneration. Mice deficient in zinc metalloproteinase STE24 (Zmpste24−/−) exhibit premature age-related musculoskeletal pathologies similar to those observed in children with Hutchinson-Gilford progeria syndrome (HGPS). We have reported that muscle-derived stem/progenitor cells (MDSPCs) isolated from Zmpste24−/− mice are defective in their proliferation and differentiation capabilities in culture and during tissue regeneration. The mechanistic target of rapamycin complex 1 (mTORC1) regulates cell growth, and inhibition of the mTORC1 pathway extends the lifespan of several animal species. We therefore hypothesized that inhibition of mTORC1 signaling would rescue the differentiation defects observed in progeroid MDSPCs. MDSPCs were isolated from Zmpste24−/− mice, and the effects of mTORC1 on MDSPC differentiation and function were examined. We found that mTORC1 signaling was increased in senescent Zmpste24−/− MDSPCs, along with impaired chondrogenic, osteogenic, and myogenic differentiation capacity versus wild-type MDSPCs. Interestingly, we observed that mTORC1 inhibition with rapamycin improved myogenic and chondrogenic differentiation and reduced levels of apoptosis and senescence in Zmpste24−/− MDSPCs. Our results demonstrate that age-related adult stem/progenitor cell dysfunction contributes to impaired regenerative capacities and that mTORC1 inhibition may represent a potential therapeutic strategy for improving differentiation capacities of senescent stem and muscle progenitor cells.
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Affiliation(s)
- Yohei Kawakami
- Stem Cell Research Center, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA.,Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - William S Hambright
- Department of Orthopaedic Surgery, University of Texas Health Science Center at Houston, Houston, TX 77054, USA.,Steadman Philippon Research Institute, Vail, CO 81657, USA
| | - Koji Takayama
- Stem Cell Research Center, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA.,Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - Xiaodong Mu
- Stem Cell Research Center, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA.,Department of Orthopaedic Surgery, University of Texas Health Science Center at Houston, Houston, TX 77054, USA.,Steadman Philippon Research Institute, Vail, CO 81657, USA
| | - Aiping Lu
- Stem Cell Research Center, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA.,Department of Orthopaedic Surgery, University of Texas Health Science Center at Houston, Houston, TX 77054, USA.,Steadman Philippon Research Institute, Vail, CO 81657, USA
| | - James H Cummins
- Stem Cell Research Center, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Tomoyuki Matsumoto
- Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - Takashi Yurube
- Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - Ryosuke Kuroda
- Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - Masahiro Kurosaka
- Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - Freddie H Fu
- Stem Cell Research Center, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Paul D Robbins
- Department of Biochemistry, Molecular Biology and Biophysics, Institute on Biology of Aging and Metabolism, University of Minnesota, Minneapolis, MN 55455, USA
| | - Laura J Niedernhofer
- Department of Biochemistry, Molecular Biology and Biophysics, Institute on Biology of Aging and Metabolism, University of Minnesota, Minneapolis, MN 55455, USA
| | - Johnny Huard
- Steadman Philippon Research Institute, Vail, CO 81657, USA
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23
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Gonzalez JT, Betts JA, Thompson D. Carbohydrate Availability as a Regulator of Energy Balance With Exercise. Exerc Sport Sci Rev 2019; 47:215-222. [DOI: 10.1249/jes.0000000000000196] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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24
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Gancheva S, Jelenik T, Álvarez-Hernández E, Roden M. Interorgan Metabolic Crosstalk in Human Insulin Resistance. Physiol Rev 2018; 98:1371-1415. [PMID: 29767564 DOI: 10.1152/physrev.00015.2017] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Excessive energy intake and reduced energy expenditure drive the development of insulin resistance and metabolic diseases such as obesity and type 2 diabetes mellitus. Metabolic signals derived from dietary intake or secreted from adipose tissue, gut, and liver contribute to energy homeostasis. Recent metabolomic studies identified novel metabolites and enlarged our knowledge on classic metabolites. This review summarizes the evidence of their roles as mediators of interorgan crosstalk and regulators of insulin sensitivity and energy metabolism. Circulating lipids such as free fatty acids, acetate, and palmitoleate from adipose tissue and short-chain fatty acids from the gut effectively act on liver and skeletal muscle. Intracellular lipids such as diacylglycerols and sphingolipids can serve as lipotoxins by directly inhibiting insulin action in muscle and liver. In contrast, fatty acid esters of hydroxy fatty acids have been recently shown to exert a series of beneficial effects. Also, ketoacids are gaining interest as potent modulators of insulin action and mitochondrial function. Finally, branched-chain amino acids not only predict metabolic diseases, but also inhibit insulin signaling. Here, we focus on the metabolic crosstalk in humans, which regulates insulin sensitivity and energy homeostasis in the main insulin-sensitive tissues, skeletal muscle, liver, and adipose tissue.
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Affiliation(s)
- Sofiya Gancheva
- Division of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University , Düsseldorf , Germany ; Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University , Düsseldorf , Germany ; and German Center of Diabetes Research (DZD e.V.), Munich- Neuherberg , Germany
| | - Tomas Jelenik
- Division of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University , Düsseldorf , Germany ; Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University , Düsseldorf , Germany ; and German Center of Diabetes Research (DZD e.V.), Munich- Neuherberg , Germany
| | - Elisa Álvarez-Hernández
- Division of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University , Düsseldorf , Germany ; Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University , Düsseldorf , Germany ; and German Center of Diabetes Research (DZD e.V.), Munich- Neuherberg , Germany
| | - Michael Roden
- Division of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University , Düsseldorf , Germany ; Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University , Düsseldorf , Germany ; and German Center of Diabetes Research (DZD e.V.), Munich- Neuherberg , Germany
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Amino acids stimulate the endosome-to-Golgi trafficking through Ragulator and small GTPase Arl5. Nat Commun 2018; 9:4987. [PMID: 30478271 PMCID: PMC6255761 DOI: 10.1038/s41467-018-07444-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 10/31/2018] [Indexed: 11/22/2022] Open
Abstract
The endosome-to-Golgi or endocytic retrograde trafficking pathway is an important post-Golgi recycling route. Here we show that amino acids (AAs) can stimulate the retrograde trafficking and regulate the cell surface localization of certain Golgi membrane proteins. By testing components of the AA-stimulated mTORC1 signaling pathway, we demonstrate that SLC38A9, v-ATPase and Ragulator, but not Rag GTPases and mTORC1, are essential for the AA-stimulated trafficking. Arl5, an ARF-like family small GTPase, interacts with Ragulator in an AA-regulated manner and both Arl5 and its effector, the Golgi-associated retrograde protein complex (GARP), are required for the AA-stimulated trafficking. We have therefore identified a mechanistic connection between the nutrient signaling and the retrograde trafficking pathway, whereby SLC38A9 and v-ATPase sense AA-sufficiency and Ragulator might function as a guanine nucleotide exchange factor to activate Arl5, which, together with GARP, a tethering factor, probably facilitates the endosome-to-Golgi trafficking. Amino acid levels are known to regulate anabolic and catabolic pathways. Here, the authors report that amino acids also affect membrane trafficking by stimulating endosome-to-Golgi retrograde trafficking and regulating cell surface localization of certain Golgi proteins through Ragulator and Arl5.
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26
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Leptin Signaling in the Control of Metabolism and Appetite: Lessons from Animal Models. J Mol Neurosci 2018; 66:390-402. [DOI: 10.1007/s12031-018-1185-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 09/24/2018] [Indexed: 12/15/2022]
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27
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Yau WW, Singh BK, Lesmana R, Zhou J, Sinha RA, Wong KA, Wu Y, Bay BH, Sugii S, Sun L, Yen PM. Thyroid hormone (T 3) stimulates brown adipose tissue activation via mitochondrial biogenesis and MTOR-mediated mitophagy. Autophagy 2018; 15:131-150. [PMID: 30209975 DOI: 10.1080/15548627.2018.1511263] [Citation(s) in RCA: 134] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The thyroid hormone triiodothyronine (T3) activates thermogenesis by uncoupling electron transport from ATP synthesis in brown adipose tissue (BAT) mitochondria. Although T3 can induce thermogenesis by sympathetic innervation, little is known about its cell autonomous effects on BAT mitochondria. We thus examined effects of T3 on mitochondrial activity, autophagy, and metabolism in primary brown adipocytes and BAT and found that T3 increased fatty acid oxidation and mitochondrial respiration as well as autophagic flux, mitophagy, and mitochondrial biogenesis. Interestingly, there was no significant induction of intracellular reactive oxygen species (ROS) despite high mitochondrial respiration and UCP1 induction by T3. However, when cells were treated with Atg5 siRNA to block autophagy, induction of mitochondrial respiration by T3 decreased, and was accompanied by ROS accumulation, demonstrating a critical role for autophagic mitochondrial turnover. We next generated an Atg5 conditional knockout mouse model (Atg5 cKO) by injecting Ucp1 promoter-driven Cre-expressing adenovirus into Atg5Flox/Flox mice to examine effects of BAT-specific autophagy on thermogenesis in vivo. Hyperthyroid Atg5 cKO mice exhibited lower body temperature than hyperthyroid or euthyroid control mice. Metabolomic analysis showed that T3 increased short and long chain acylcarnitines in BAT, consistent with increased β-oxidation. T3 also decreased amino acid levels, and in conjunction with SIRT1 activation, decreased MTOR activity to stimulate autophagy. In summary, T3 has direct effects on mitochondrial autophagy, activity, and turnover in BAT that are essential for thermogenesis. Stimulation of BAT activity by thyroid hormone or its analogs may represent a potential therapeutic strategy for obesity and metabolic diseases. Abbreviations: ACACA: acetyl-Coenzyme A carboxylase alpha; AMPK: AMP-activated protein kinase; Acsl1: acyl-CoA synthetase long-chain family member 1; ATG5: autophagy related 5; ATG7: autophagy related 7; ATP: adenosine triphosphate; BAT: brown adipose tissue; cKO: conditional knockout; COX4I1: cytochrome c oxidase subunit 4I1; Cpt1b: carnitine palmitoyltransferase 1b, muscle; CQ: chloroquine; DAPI: 4',6-diamidino-2-phenylindole; DIO2: deiodinase, iodothyronine, type 2; DMEM: Dulbecco's modified Eagle's medium; EIF4EBP1: eukaryotic translation initiation factor 4E binding protein 1; Fabp4: fatty acid binding protein 4, adipocyte; FBS: fetal bovine serum; FCCP: carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone; FGF: fibroblast growth factor; FOXO1: forkhead box O1; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GFP: green fluorescent protein; Gpx1: glutathione peroxidase 1; Lipe: lipase, hormone sensitive; MAP1LC3B: microtubule-associated protein 1 light chain 3; mRNA: messenger RNA; MTORC1: mechanistic target of rapamycin kinase complex 1; NAD: nicotinamide adenine dinucleotide; Nrf1: nuclear respiratory factor 1; OCR: oxygen consumption rate; PBS: phosphate-buffered saline; PCR: polymerase chain reaction; PPARGC1A: peroxisome proliferative activated receptor, gamma, coactivator 1 alpha; Pnpla2: patatin-like phospholipase domain containing 2; Prdm16: PR domain containing 16; PRKA: protein kinase, AMP-activated; RPS6KB: ribosomal protein S6 kinase; RFP: red fluorescent protein; ROS: reactive oxygen species; SD: standard deviation; SEM: standard error of the mean; siRNA: small interfering RNA; SIRT1: sirtuin 1; Sod1: superoxide dismutase 1, soluble; Sod2: superoxide dismutase 2, mitochondrial; SQSTM1: sequestosome 1; T3: 3,5,3'-triiodothyronine; TFEB: transcription factor EB; TOMM20: translocase of outer mitochondrial membrane 20; UCP1: uncoupling protein 1 (mitochondrial, proton carrier); ULK1: unc-51 like kinase 1; VDAC1: voltage-dependent anion channel 1; WAT: white adipose tissue.
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Affiliation(s)
- Winifred W Yau
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore
| | - Brijesh K Singh
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore
| | - Ronny Lesmana
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore.,b Physiology Division, Department of Anatomy, Physiology and Biology Cell, Faculty of Medicine , Universitas Padjadjaran , Bandung , Indonesia.,c Central laboratory , Universitas Padjadjaran , Bandung , Indonesia
| | - Jin Zhou
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore
| | - Rohit A Sinha
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore.,d Department of Endocrinology , Sanjay Gandhi Postgraduate Institute of Medical Sciences , Lucknow , India
| | - Kiraely A Wong
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore
| | - Yajun Wu
- e Department of Anatomy , Yong Loo Lin School of Medicine, National University of Singapore , Singapore
| | - Boon-Huat Bay
- e Department of Anatomy , Yong Loo Lin School of Medicine, National University of Singapore , Singapore
| | - Shigeki Sugii
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore.,f Fat Metabolism and Stem Cell Group , Singapore Bioimaging Consortium, A*STAR , Singapore
| | - Lei Sun
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore
| | - Paul M Yen
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore.,g Sarah W. Stedman Nutrition and Metabolism Center, Departments of Medicine and Pharmacology and Cancer Biology , Duke University Medical Center , Durham , NC , USA
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Ali M, Bukhari SA, Ali M, Lee HW. Upstream signalling of mTORC1 and its hyperactivation in type 2 diabetes (T2D). BMB Rep 2018; 50:601-609. [PMID: 29187279 PMCID: PMC5749905 DOI: 10.5483/bmbrep.2017.50.12.206] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Indexed: 12/19/2022] Open
Abstract
Mammalian target of rapamycin complex 1 (mTORC1) plays a major role in cell growth, proliferation, polarity, differentiation, development, and controls transitioning between anabolic and catabolic states of the cell. It collects almost all extracellular and intracellular signals from growth factors, nutrients, and maintains cellular homeostasis, and is involved in several pathological conditions including, neurodegeneration, Type 2 diabetes (T2D), obesity, and cancer. In this review, we summarize current knowledge of upstream signaling of mTORC1 to explain etiology of T2D and hypertriglyceridemia, in which state, the role of telomere attrition is explained. We discuss if chronic inhibition of mTORC1 can reverse adverse effects resulting from hyperactivation. In conclusion, we suggest the regulatory roles of telomerase (TERT) and hexokinase II (HKII) on mTORC1 as possible remedies to treat hyperactivation. The former inhibits mTORC1 under nutrient-rich while the latter under starved condition. We provide an idea of TOS (TOR signaling) motifs that can be used for regulation of mTORC1.
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Affiliation(s)
- Muhammad Ali
- Departments of Biochemistry, Government College University, Faisalabad, 38000 Pakistan
| | - Shazia Anwer Bukhari
- Departments of Biochemistry, Government College University, Faisalabad, 38000 Pakistan
| | - Muhammad Ali
- Departments of Zoology, Government College University, Faisalabad, 38000 Pakistan
| | - Han-Woong Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Republic of Korea
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Naz S, Sowers A, Choudhuri R, Wissler M, Gamson J, Mathias A, Cook JA, Mitchell JB. Abemaciclib, a Selective CDK4/6 Inhibitor, Enhances the Radiosensitivity of Non-Small Cell Lung Cancer In Vitro and In Vivo. Clin Cancer Res 2018; 24:3994-4005. [PMID: 29716919 DOI: 10.1158/1078-0432.ccr-17-3575] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 03/30/2018] [Accepted: 04/27/2018] [Indexed: 12/22/2022]
Abstract
Purpose: To characterize the ionizing radiation (IR) enhancing effects and underlying mechanisms of the CDK4/6 inhibitor abemaciclib in non-small cell lung cancer (NSCLC) cells in vitro and in vivoExperimental Design: IR enhancement by abemaciclib in a variety of NSCLC cell lines was assessed by in vitro clonogenic assay, flow cytometry, and target inhibition verified by immunoblotting. IR-induced DNA damage repair was evaluated by γH2AX analysis. Global metabolic alterations by abemaciclib and IR combination were evaluated by LC/MS mass spectrometry and YSI bioanalyzer. Effects of abemaciclib and IR combination in vivo were studied by xenograft tumor regrowth delay, xenograft lysate immunoblotting, and tissue section immunohistochemistry.Results: Abemaciclib enhanced the radiosensitivity of NSCLC cells independent of RAS or EGFR status. Enhancement of radiosensitivity was lost in cell lines deficient for functional p53 and RB protein. After IR, abemaciclib treatment inhibited DNA damage repair as measured by γH2AX. Mechanistically, abemaciclib inhibited RB phosphorylation, leading to cell-cycle arrest. It also inhibited mTOR signaling and reduced intracellular amino acid pools, causing nutrient stress. In vivo, abemaciclib, when administered in an adjuvant setting for the second week after fractionated IR, further inhibited vasculogenesis and tumor regrowth, with sustained inhibition of RB/E2F activity, mTOR pathway, and HIF-1 expression. In summary, our study signifies inhibiting the CDK4/6 pathway by abemaciclib in combination with IR as a promising therapeutic strategy to treat NSCLC.Conclusions: Abemaciclib in combination with IR enhances NSCLC radiosensitivity in preclinical models, potentially providing a novel biomarker-driven combination therapeutic strategy for patients with NSCLC. Clin Cancer Res; 24(16); 3994-4005. ©2018 AACR.
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Affiliation(s)
- Sarwat Naz
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Anastasia Sowers
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Rajani Choudhuri
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Maria Wissler
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Janet Gamson
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Askale Mathias
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - John A Cook
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - James B Mitchell
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland.
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Microbiome-metabolome signatures in mice genetically prone to develop dementia, fed a normal or fatty diet. Sci Rep 2018; 8:4907. [PMID: 29559675 PMCID: PMC5861049 DOI: 10.1038/s41598-018-23261-1] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 02/26/2018] [Indexed: 02/06/2023] Open
Abstract
Cognitive decline, obesity and gut dysfunction or microbial dysbiosis occur in association. Our aim was to identify gut microbiota-metabolomics signatures preceding dementia in genetically prone (3xtg) mice, with and without superimposed high-fat diet. We examined the composition and diversity of their gut microbiota, and serum and faecal metabolites. 3xtg mice showed brain hypometabolism typical of pre-demented stage, and lacked the physiological bacterial diversity between caecum and colon seen in controls. Cluster analyses revealed distinct profiles of microbiota, and serum and fecal metabolome across groups. Elevation in Firmicutes-to-Bacteroidetes abundance, and exclusive presence of Turicibacteraceae, Christensenellaceae, Anaeroplasmataceae and Ruminococcaceae, and lack of Bifidobacteriaceae, were also observed. Metabolome analysis revealed a deficiency in unsaturated fatty acids and choline, and an overabundance in ketone bodies, lactate, amino acids, TMA and TMAO in 3xtg mice, with additive effects of high-fat diet. These metabolic alterations were correlated with high prevalence of Enterococcaceae, Staphylococcus, Roseburia, Coprobacillus and Dorea, and low prevalence of S24.7, rc4.4 and Bifidobacterium, which in turn related to cognitive impairment and cerebral hypometabolism. Our results indicate an effect of transgenic background on gut microbiome-metabolome, enhanced by high-fat diet. The resulting profiles may precede overt cognitive impairment, suggesting their predictive or risk-stratifying potential.
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Direct Sensing of Nutrients via a LAT1-like Transporter in Drosophila Insulin-Producing Cells. Cell Rep 2017; 17:137-148. [PMID: 27681427 PMCID: PMC5055474 DOI: 10.1016/j.celrep.2016.08.093] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 07/28/2016] [Accepted: 08/29/2016] [Indexed: 12/22/2022] Open
Abstract
Dietary leucine has been suspected to play an important role in insulin release, a hormone that controls satiety and metabolism. The mechanism by which insulin-producing cells (IPCs) sense leucine and regulate insulin secretion is still poorly understood. In Drosophila, insulin-like peptides (DILP2 and DILP5) are produced by brain IPCs and are released in the hemolymph after leucine ingestion. Using Ca2+-imaging and ex vivo cultured larval brains, we demonstrate that IPCs can directly sense extracellular leucine levels via minidiscs (MND), a leucine transporter. MND knockdown in IPCs abolished leucine-dependent changes, including loss of DILP2 and DILP5 in IPC bodies, consistent with the idea that MND is necessary for leucine-dependent DILP release. This, in turn, leads to a strong increase in hemolymph sugar levels and reduced growth. GDH knockdown in IPCs also reduced leucine-dependent DILP release, suggesting that nutrient sensing is coupled to the glutamate dehydrogenase pathway. IPCs directly sense extracellular leucine levels via minidiscs (MND) MND knockdown in IPCs abolishes loss of DILP2 and DILP5 This leads to a strong increase in hemolymph sugar levels and reduces growth GDH knockdown in IPCs reduces leucine-dependent DILP release
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Cummings NE, Lamming DW. Regulation of metabolic health and aging by nutrient-sensitive signaling pathways. Mol Cell Endocrinol 2017; 455:13-22. [PMID: 27884780 PMCID: PMC5440210 DOI: 10.1016/j.mce.2016.11.014] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 10/07/2016] [Accepted: 11/19/2016] [Indexed: 01/20/2023]
Abstract
All organisms need to be capable of adapting to changes in the availability and composition of nutrients. Over 75 years ago, researchers discovered that a calorie restricted (CR) diet could significantly extend the lifespan of rats, and since then a CR diet has been shown to increase lifespan and healthspan in model organisms ranging from yeast to non-human primates. In this review, we discuss the effects of a CR diet on metabolism and healthspan, and highlight emerging evidence that suggests that dietary composition - the precise macronutrients that compose the diet - may be just as important as caloric content. In particular, we discuss recent evidence that suggests protein quality may influence metabolic health. Finally, we discuss key metabolic pathways which may influence the response to CR diets and altered macronutrient composition. Understanding the molecular mechanisms responsible for the effects of CR and dietary composition on health and longevity may allow the design of novel therapeutic approaches to age-related diseases.
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Affiliation(s)
- Nicole E Cummings
- Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA; William S. Middleton Memorial Veterans Hospital, Madison, WI, USA; Endocrinology and Reproductive Physiology Graduate Training Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Dudley W Lamming
- Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA; William S. Middleton Memorial Veterans Hospital, Madison, WI, USA; Endocrinology and Reproductive Physiology Graduate Training Program, University of Wisconsin-Madison, Madison, WI, USA.
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The effects of reduced dietary protein level on amino acid transporters and mTOR signaling pathway in pigs. Biochem Biophys Res Commun 2017; 485:319-327. [DOI: 10.1016/j.bbrc.2017.02.084] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 02/16/2017] [Indexed: 12/17/2022]
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Crowell KT, Soybel DI, Lang CH. Inability to replete white adipose tissue during recovery phase of sepsis is associated with increased autophagy, apoptosis, and proteasome activity. Am J Physiol Regul Integr Comp Physiol 2017; 312:R388-R399. [PMID: 28100477 DOI: 10.1152/ajpregu.00498.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 12/30/2016] [Accepted: 01/13/2017] [Indexed: 12/20/2022]
Abstract
Adipose tissue is an important energy depot and endocrine organ, and the degree of adiposity impacts the host response to infection. However, little is known regarding the mechanisms by which white adipose tissue (WAT) is lost acutely and then restored after the resolution of sepsis. Therefore, the signaling pathways governing protein synthesis, autophagy, apoptosis, and the ubiquitin-proteasome were investigated to identify potential mechanisms mediating the acute (24 h) loss of WAT after cecal ligation and puncture as well as the failure to replenish WAT during recovery (day 10). While whole body fat mass was decreased equally in pair-fed control and septic mice at 5 days after cecal ligation and puncture, fat mass remained 35% lower in septic mice at day 10 During sepsis-recovery, protein synthesis in epididymal WAT was increased compared with control values, and this increase was associated with an elevation in eukaryotic translation initiation factor (eIF)2Bε but no change in mammalian target of rapamycin complex 1 activity (eIF4E-binding protein-1 or S6 kinase 1 phosphorylation). Protein breakdown was increased during sepsis-recovery, as evidenced by the elevation in ubiquitin-proteasome activity. Moreover, indexes of autophagy (light chain 3B-II, autophagy-related protein 5/12, and beclin) were increased during sepsis-recovery and associated with increased AMP-activated kinase-dependent Ser555-phosphorylated Unc-51-like autophagy activating kinase-1. Apoptosis was increased, as suggested by the increased cleavage of caspase-3 and poly(ADP-ribose) polymerase. These changes were associated with increased inflammasome activity (increased NLR family, pyrin domain containing 3; TMS1; and caspase-1 cleavage) and the endoplasmic reticulum stress response (increased eIF2α and activating transcription factor-4) and browning (uncoupling protein-1) in epididymal WAT. Our data suggest that WAT stores remain depleted during recovery from sepsis due to sustained inflammation and elevations in protein and cellular degradation, despite the increase in protein synthesis.
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Affiliation(s)
- Kristen T Crowell
- Department of Surgery, Penn State College of Medicine, Hershey, Pennsylvania
| | - David I Soybel
- Department of Surgery, Penn State College of Medicine, Hershey, Pennsylvania.,Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania; and.,Department of Nutritional Sciences, Penn State University, University Park, Pennsylvania
| | - Charles H Lang
- Department of Surgery, Penn State College of Medicine, Hershey, Pennsylvania .,Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania; and
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Natarajan SK, Muthukrishnan E, Khalimonchuk O, Mott JL, Becker DF. Evidence for Pipecolate Oxidase in Mediating Protection Against Hydrogen Peroxide Stress. J Cell Biochem 2016; 118:1678-1688. [PMID: 27922192 DOI: 10.1002/jcb.25825] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 12/02/2016] [Indexed: 01/16/2023]
Abstract
Pipecolate, an intermediate of the lysine catabolic pathway, is oxidized to Δ1 -piperideine-6-carboxylate (P6C) by the flavoenzyme l-pipecolate oxidase (PIPOX). P6C spontaneously hydrolyzes to generate α-aminoadipate semialdehyde, which is then converted into α-aminoadipate acid by α-aminoadipatesemialdehyde dehydrogenase. l-pipecolate was previously reported to protect mammalian cells against oxidative stress. Here, we examined whether PIPOX is involved in the mechanism of pipecolate stress protection. Knockdown of PIPOX by small interference RNA abolished pipecolate protection against hydrogen peroxide-induced cell death in HEK293 cells suggesting a critical role for PIPOX. Subcellular fractionation analysis showed that PIPOX is localized in the mitochondria of HEK293 cells consistent with its role in lysine catabolism. Signaling pathways potentially involved in pipecolate protection were explored by treating cells with small molecule inhibitors. Inhibition of both mTORC1 and mTORC2 kinase complexes or inhibition of Akt kinase alone blocked pipecolate protection suggesting the involvement of these signaling pathways. Phosphorylation of the Akt downstream target, forkhead transcription factor O3 (FoxO3), was also significantly increased in cells treated with pipecolate, further implicating Akt in the protective mechanism and revealing FoxO3 inhibition as a potentially key step. The results presented here demonstrate that pipecolate metabolism can influence cell signaling during oxidative stress to promote cell survival and suggest that the mechanism of pipecolate protection parallels that of proline, which is also metabolized in the mitochondria. J. Cell. Biochem. 118: 1678-1688, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Sathish Kumar Natarajan
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588.,Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, 68583
| | - Ezhumalai Muthukrishnan
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, 68583
| | - Oleh Khalimonchuk
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588
| | - Justin L Mott
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska, 68198
| | - Donald F Becker
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588
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Ali M, Devkota S, Roh JI, Lee J, Lee HW. Telomerase reverse transcriptase induces basal and amino acid starvation-induced autophagy through mTORC1. Biochem Biophys Res Commun 2016; 478:1198-204. [DOI: 10.1016/j.bbrc.2016.08.094] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 08/16/2016] [Indexed: 01/06/2023]
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Crowell KT, Steiner JL, Coleman CS, Lang CH. Decreased Whole-Body Fat Mass Produced by Chronic Alcohol Consumption is Associated with Activation of S6K1-Mediated Protein Synthesis and Increased Autophagy in Epididymal White Adipose Tissue. Alcohol Clin Exp Res 2016; 40:1832-45. [PMID: 27464336 DOI: 10.1111/acer.13159] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 06/23/2016] [Indexed: 12/25/2022]
Abstract
BACKGROUND Chronic alcohol consumption leads to a loss of white adipose tissue (WAT) but the underlying mechanisms for this lipodystrophy are not fully elucidated. This study tested the hypothesis that the reduction in WAT mass in chronic alcohol-fed mice is associated with a decreased protein synthesis specifically related to impaired function of mammalian target of rapamycin (mTOR). METHODS Adult male mice were provided an alcohol-containing liquid diet for 24 weeks or an isonitrogenous isocaloric control diet. In vivo protein synthesis was determined at this time and thereafter epididymal WAT (eWAT) was excised for analysis of signal transduction pathways central to controling protein synthesis and degradation. RESULTS While chronic alcohol feeding decreased whole-body and eWAT mass, this was associated with a discordant increase in protein synthesis in eWAT. This increase was not associated with a change in mTOR, 4E-BP1, Akt, or PRAS40 phosphorylation. Instead, a selective increase in phosphorylation of S6K1 and its downstream substrates, S6 and eIF4B was detected in alcohol-fed mice. Alcohol also increased eEF2K phosphorylation and decreased eEF2 phosphorylation consistent with increased translation elongation. Alcohol increased Atg12-5, LC3B-I and -II, and ULK1 S555 phosphorylation, suggesting increased autophagy, while markers of apoptosis (cleaved caspase-3 and -9, and PARP) were unchanged. Lipolytic enzymes (ATGL and HSL phosphorylation) were increased and lipogenic regulators (PPARγ and C/EBPα) were decreased in eWAT by alcohol. Although alcohol increased TNF-α, IL-6, and IL-1β mRNA, no change in key components of the NLRP3 inflammasome (NLRP3, ACS, and cleaved caspase-1) was detected suggesting alcohol did not increase pyroptosis. Plasma insulin did not differ between groups. CONCLUSIONS These results demonstrate that the alcohol-induced decrease in whole-body fat mass resulted in part from activation of autophagy in eWAT as protein synthesis was increased and mediated by the specific increase in the activity of S6K1.
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Affiliation(s)
- Kristen T Crowell
- Department of Cellular and Molecular Physiology, Penn State College Medicine, Hershey, Pennsylvania.,Department of Surgery, Penn State College Medicine, Hershey, Pennsylvania
| | - Jennifer L Steiner
- Department of Cellular and Molecular Physiology, Penn State College Medicine, Hershey, Pennsylvania
| | - Catherine S Coleman
- Department of Cellular and Molecular Physiology, Penn State College Medicine, Hershey, Pennsylvania
| | - Charles H Lang
- Department of Cellular and Molecular Physiology, Penn State College Medicine, Hershey, Pennsylvania.,Department of Surgery, Penn State College Medicine, Hershey, Pennsylvania
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Escalante G, Alencar M, Haddock B, Harvey P. The effects of phosphatidic acid supplementation on strength, body composition, muscular endurance, power, agility, and vertical jump in resistance trained men. J Int Soc Sports Nutr 2016; 13:24. [PMID: 27274715 PMCID: PMC4891923 DOI: 10.1186/s12970-016-0135-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 05/27/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Phosphatidic acid (PA) is a lipid messenger that has been shown to increase muscle protein synthesis via signaling stimulation of the mammalian target of rapamycin (mTOR). MaxxTOR® (MT) is a supplement that contains PA as the main active ingredient but also contains other synergistic mTOR signaling substances including L-Leucine, Beta-Hydroxy-Beta-Methylbutyrate (HMB), and Vitamin D3. METHODS Eighteen healthy strength-trained males were randomly assigned to a group that either consumed MT (n = 8, 22.0 +/- 2.5 years; 175.8 +/- 11.5 cm; 80.3 +/- 15.1 kg) or a placebo (PLA) (n = 10, 25.6 +/- 4.2 years; 174.8 +/- 9.0 cm; 88.6 +/- 16.6 kg) as part of a double-blind, placebo controlled pre/post experimental design. All participants volunteered to complete the three day per week resistance training protocol for the eight week study duration. To determine the effects of MT, participants were tested on one repetition maximum (1RM) leg press strength (LP), 1RM bench press strength (BP), push-ups to failure (PU), vertical jump (VJ), pro-agility shuttle time (AG), peak power output (P), lean body mass (LBM), fat mass (FM), and thigh muscle mass (TMM). Subjects were placed and monitored on an isocaloric diet consisting of 25 protein, 50 carbohydrates, and 25 % fat by a registered dietitian. Separate two-way mixed factorial repeated measures ANOVA's (time [Pre, Post] x group [MT and PLA] were used to investigate strength, body composition, and other performance changes. Post-hoc tests were applied as appropriate. Analysis were performed via SPSS with significance at (p ≤ 0.05). RESULTS There was a significant main effect (F(1,16) = 33.30, p < 0.001) for LBM where MT significantly increased LBM when compared to the PLA group (p < 0.001). Additionally, there was a significant main effect for LP (F(1,16) = 666.74, p < 0.001) and BP (F(1,16) = 126.36, p < 0.001) where both increased significantly more in MT than PLA group (p < 0.001). No significant differences between MT and PLA were noted for FM, TMM, VJ, AG, P, or PU. CONCLUSION The results of this eight week trial suggest that the addition of MaxxTOR® to a 3-day per week resistance training program can positively impact LBM and strength beyond the results found with exercise alone.
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Affiliation(s)
- Guillermo Escalante
- California State University- San Bernardino, 5500 University Parkway, San Bernardino, CA 92407 USA
| | - Michelle Alencar
- California State University- Long Beach, 1250 Bellflower Boulevard, Long Beach, CA 90840 USA
| | - Bryan Haddock
- California State University- San Bernardino, 5500 University Parkway, San Bernardino, CA 92407 USA
| | - Phillip Harvey
- Max Muscle Sports Nutrition, 210 West Taft Avenue, Orange, CA 92865 USA ; University of Phoenix, San Diego Campus, 9645 Granite Ridge Drive, San Diego, CA 92123 USA
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Bhoj EJ, Li D, Harr M, Edvardson S, Elpeleg O, Chisholm E, Juusola J, Douglas G, Guillen Sacoto MJ, Siquier-Pernet K, Saadi A, Bole-Feysot C, Nitschke P, Narravula A, Walke M, Horner MB, Day-Salvatore DL, Jayakar P, Vergano SAS, Tarnopolsky MA, Hegde M, Colleaux L, Crino P, Hakonarson H. Mutations in TBCK, Encoding TBC1-Domain-Containing Kinase, Lead to a Recognizable Syndrome of Intellectual Disability and Hypotonia. Am J Hum Genet 2016; 98:782-8. [PMID: 27040691 DOI: 10.1016/j.ajhg.2016.03.016] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Accepted: 03/16/2016] [Indexed: 12/15/2022] Open
Abstract
Through an international multi-center collaboration, 13 individuals from nine unrelated families and affected by likely pathogenic biallelic variants in TBC1-domain-containing kinase (TBCK) were identified through whole-exome sequencing. All affected individuals were found to share a core phenotype of intellectual disability and hypotonia, and many had seizures and showed brain atrophy and white-matter changes on neuroimaging. Minor non-specific facial dysmorphism was also noted in some individuals, including multiple older children who developed coarse features similar to those of storage disorders. TBCK has been shown to regulate the mammalian target of rapamycin (mTOR) signaling pathway, which is also stimulated by exogenous leucine supplementation. TBCK was absent in cells from affected individuals, and decreased phosphorylation of phospho-ribosomal protein S6 was also observed, a finding suggestive of downregulation of mTOR signaling. Lastly, we demonstrated that activation of the mTOR pathway in response to L-leucine supplementation was retained, suggesting a possible avenue for directed therapies for this condition.
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Affiliation(s)
- Elizabeth J Bhoj
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Genetics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
| | - Dong Li
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Margaret Harr
- Department of Genetics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Shimon Edvardson
- Pediatric Neurology Unit, Hadassah University Hospital, Mount Scopus, Jerusalem 91120, Israel; Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Orly Elpeleg
- Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Elizabeth Chisholm
- Division of Medical Genetics and Metabolism, Children's Hospital of The King's Daughters, Norfolk, VA 23507, USA
| | | | | | | | - Karine Siquier-Pernet
- INSERM UMR 1163, Laboratory of Molecular and Pathophysiological Bases of Cognitive Disorders, Université Paris Descartes, Sorbonne Paris Cité, Institut Imagine, Necker-Enfants Malades Hospital, 75015 Paris, France
| | - Abdelkrim Saadi
- Département de Neurologie, Etablissement Hospitalier Spécialisé de Benaknoun, Algers, Algeria
| | - Christine Bole-Feysot
- Genomic Platform, INSERM UMR 1163, Université Paris Descartes, Sorbonne Paris Cité, Institut Imagine, 75015 Paris, France
| | - Patrick Nitschke
- Plateforme de Bioinformatique, Université Paris Descartes, Sorbonne Paris Cité, Institut Imagine, 75015 Paris, France
| | | | - Maria Walke
- Nicklaus Children's Hospital, Miami, FL, 33155, USA
| | - Michele B Horner
- Department of Medical Genetics & Genomic Medicine, St. Peter's University Hospital, New Brunswick, NJ 08901, USA
| | - Debra-Lynn Day-Salvatore
- Department of Medical Genetics & Genomic Medicine, St. Peter's University Hospital, New Brunswick, NJ 08901, USA
| | | | - Samantha A Schrier Vergano
- Division of Medical Genetics and Metabolism, Children's Hospital of The King's Daughters, Norfolk, VA 23507, USA
| | - Mark A Tarnopolsky
- Department of Pediatrics, McMaster University Medical Center, Hamilton, ON L8N 3Z5, Canada
| | - Madhuri Hegde
- Emory Genetics Laboratory, Emory University, Decatur, GA 30033, USA
| | - Laurence Colleaux
- INSERM UMR 1163, Laboratory of Molecular and Pathophysiological Bases of Cognitive Disorders, Université Paris Descartes, Sorbonne Paris Cité, Institut Imagine, Necker-Enfants Malades Hospital, 75015 Paris, France
| | - Peter Crino
- Department of Neurology, Temple University, Philadelphia, PA 19122, USA
| | - Hakon Hakonarson
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
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Luque V, Closa-Monasterolo R, Escribano J, Ferré N. Early Programming by Protein Intake: The Effect of Protein on Adiposity Development and the Growth and Functionality of Vital Organs. Nutr Metab Insights 2016; 8:49-56. [PMID: 27013888 PMCID: PMC4803318 DOI: 10.4137/nmi.s29525] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Revised: 12/14/2015] [Accepted: 12/16/2015] [Indexed: 12/22/2022] Open
Abstract
This article reviews the role of protein intake on metabolic programming early in life. The observations that breastfeeding in infancy reduces the risk of being overweight and obese later in life and the differences in the protein content between formula milk and human milk have generated the early protein hypothesis. The present review focuses on a mechanistic approach to programmed adiposity and the growth and development of other organs by protein intake in infancy, which may be mediated by branched-chain amino acids, insulin, and insulin-like growth factor 1 via the mammalian target of rapamycin. Observational studies and clinical trials have shown that lowering the protein content in infant and follow-on formulas may reduce the risk of becoming obese later in life. The recent body of evidence is currently being translated into new policies. Therefore, the evolution of European regulatory laws and recommendations by expert panels on the protein content of infant and follow-on formulas are also reviewed. Research gaps, such as the critical window for programming adiposity by protein intake, testing formulas with modified amino acids, and the long-term consequences of differences in protein intake on organ functionality among well-nourished infants, have been identified.
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Affiliation(s)
- Veronica Luque
- Pediatrics, Nutrition and Development Research Unit, Universitat Rovira I Virgili, IISPV, Reus, Spain.; Hospital Universitari de Tarragona Joan XXIII, Tarragona, Spain
| | - Ricardo Closa-Monasterolo
- Pediatrics, Nutrition and Development Research Unit, Universitat Rovira I Virgili, IISPV, Reus, Spain.; Hospital Universitari de Tarragona Joan XXIII, Tarragona, Spain
| | - Joaquín Escribano
- Pediatrics, Nutrition and Development Research Unit, Universitat Rovira I Virgili, IISPV, Reus, Spain.; Hospital Universitari Sant Joan de Reus, Reus, Spain
| | - Natalia Ferré
- Pediatrics, Nutrition and Development Research Unit, Universitat Rovira I Virgili, IISPV, Reus, Spain
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Cooper LAM, Brown SL, Hocking E, Mullen AC. The role of exercise, milk, dairy foods and constituent proteins on the prevention and management of sarcopenia. INT J DAIRY TECHNOL 2015. [DOI: 10.1111/1471-0307.12280] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
| | - Sarah L Brown
- The Dairy Council; 210 High Holborn WC1V 7EP London UK
| | - Erica Hocking
- The Dairy Council; 210 High Holborn WC1V 7EP London UK
| | - Anne C Mullen
- The Dairy Council; 210 High Holborn WC1V 7EP London UK
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Kardos GR, Robertson GP. Therapeutic interventions to disrupt the protein synthetic machinery in melanoma. Pigment Cell Melanoma Res 2015; 28:501-19. [PMID: 26139519 PMCID: PMC4716672 DOI: 10.1111/pcmr.12391] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 06/30/2015] [Indexed: 01/23/2023]
Abstract
Control of the protein synthetic machinery is deregulated in many cancers, including melanoma, to increase the protein production. Tumor suppressors and oncogenes play key roles in protein synthesis from the transcription of rRNA and ribosome biogenesis to mRNA translation initiation and protein synthesis. Major signaling pathways are altered in melanoma to modulate the protein synthetic machinery, thereby promoting tumor development. However, despite the importance of this process in melanoma development, involvement of the protein synthetic machinery in this cancer type is an underdeveloped area of study. Here, we review the coupling of melanoma development to deregulation of the protein synthetic machinery. We examine existing knowledge regarding RNA polymerase I inhibition and mRNA translation focusing on their inhibition for therapeutic applications in melanoma. Furthermore, the contribution of amino acid biosynthesis and involvement of ribosomal proteins are also reviewed as future therapeutic strategies to target deregulated protein production in melanoma.
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Affiliation(s)
- Gregory R. Kardos
- Department of Pharmacology, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA, USA, 17033
- The Melanoma and Skin Cancer Center, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA, USA, 17033
- The Melanoma Therapeutics Program, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA, USA, 17033
| | - Gavin P. Robertson
- Department of Pharmacology, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA, USA, 17033
- Department of Pathology, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA, USA, 17033
- Department of Dermatology, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA, USA, 17033
- Department of Surgery, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA, USA, 17033
- The Melanoma and Skin Cancer Center, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA, USA, 17033
- The Melanoma Therapeutics Program, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA, USA, 17033
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Jang J, Yun HY, Park J, Lim K. Protective effect of branched chain amino acids on hindlimb suspension-induced muscle atrophy in growing rats. J Exerc Nutrition Biochem 2015; 19:183-9. [PMID: 26527098 PMCID: PMC4624119 DOI: 10.5717/jenb.2015.15062704] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 06/08/2015] [Accepted: 06/27/2015] [Indexed: 11/04/2022] Open
Abstract
PURPOSE The effect of BCAA (branched chain amino acid) administration on muscle atrophy during growth phases is not well known. We investigated whether BCAA administration can prevent the muscle atrophy induced by hindlimb suspension in growing male rats. METHODS Male Wistar rats were assigned to 1 of 2 groups (n = 7/group): hindlimb suspension and hindlimb suspension with oral BCAA administration (600 mg·kg(-1)·day(-1), valine 1: leucine 2: isoleucine 1). After 14 days of hindlimb suspension, the weight and mRNA levels of the soleus muscle were measured. RESULTS BCAA administration prevented a decrease in soleus muscle weight. BCAA administration attenuated atrogin-1 and MuRF1 mRNA expression, which has been reported to play a pivotal role in muscle atrophy. CONCLUSION BCAA could serve as an effective supplement for the prevention or treatment of muscle atrophy, especially atrophy caused by weightlessness.
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Affiliation(s)
- Jiwoong Jang
- Laboratory of Exercise Nutrition, Department of Physical Education, Konkuk University, Seoul, Republic of Korea
| | - Hea-Yeon Yun
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Republic of Korea
| | - Jonghoon Park
- Laboratory of Exercise Nutrition, Department of Physical Education, Konkuk University, Seoul, Republic of Korea ; Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Republic of Korea
| | - Kiwon Lim
- Laboratory of Exercise Nutrition, Department of Physical Education, Konkuk University, Seoul, Republic of Korea ; Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul, Republic of Korea
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Rouquette-Jazdanian AK, Kortum RL, Li W, Merrill RK, Nguyen PH, Samelson LE, Sommers CL. miR-155 Controls Lymphoproliferation in LAT Mutant Mice by Restraining T-Cell Apoptosis via SHIP-1/mTOR and PAK1/FOXO3/BIM Pathways. PLoS One 2015; 10:e0131823. [PMID: 26121028 PMCID: PMC4487994 DOI: 10.1371/journal.pone.0131823] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 06/06/2015] [Indexed: 12/19/2022] Open
Abstract
Linker for Activation of T cells (LAT) is an adapter protein that is essential for T cell function. Knock-in mice with a LAT mutation impairing calcium flux develop a fatal CD4+ lymphoproliferative disease. miR-155 is a microRNA that is correlated with hyperproliferation in a number of cancers including lymphomas and leukemias and is overexpressed in mutant LAT T cells. To test whether miR-155 was merely indicative of T cell activation or whether it contributes to lymphoproliferative disease in mutant LAT mice, we interbred LAT mutant and miR-155-deficient mice. miR-155 deficiency markedly inhibited lymphoproliferative disease by stimulating BIM-dependent CD4+ T cell apoptosis, even though ERK activation and T cell proliferation were increased in double mutant CD4+ T cells. Bim/Bcl2l11 expression is activated by the forkhead transcription factor FOXO3. Using miR-155-deficient, LAT mutant T cells as a discovery tool, we found two connected pathways that impact the nuclear translocation and activation of FOXO3 in T cells. One pathway is mediated by the inositide phosphatase SHIP-1 and the serine/threonine kinases AKT and PDK1. The other pathway involves PAK1 and JNK kinase activation. We define crosstalk between the two pathways via the kinase mTOR, which stabilizes PAK1. This study establishes a role for PAK1 in T cell apoptosis, which contrasts to its previously identified role in T cell proliferation. Furthermore, miR-155 regulates the delicate balance between PAK1-mediated proliferation and apoptosis in T cells impacting lymphoid organ size and function.
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Affiliation(s)
- Alexandre K. Rouquette-Jazdanian
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Robert L. Kortum
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Wenmei Li
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Robert K. Merrill
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Phan H. Nguyen
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Lawrence E. Samelson
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Connie L. Sommers
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (CLS)
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Wang X, Wei H, Cao J, Li Z, He P. Metabolomics analysis of muscle from piglets fed low protein diets supplemented with branched chain amino acids using HPLC-high-resolution MS. Electrophoresis 2015; 36:2250-2258. [DOI: 10.1002/elps.201500007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 03/15/2015] [Accepted: 03/15/2015] [Indexed: 11/08/2022]
Affiliation(s)
- Xian Wang
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology; China Agricultural University; Beijing P. R. China
| | - Hongkui Wei
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology; Huazhong Agricultural University; Wuhan P. R. China
| | - Jingjing Cao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences; China Agricultural University; Beijing P. R. China
| | - Zhen Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences; China Agricultural University; Beijing P. R. China
| | - Pingli He
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology; China Agricultural University; Beijing P. R. China
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Weng L, Quinlivan E, Gong Y, Beitelshees AL, Shahin MH, Turner ST, Chapman AB, Gums JG, Johnson JA, Frye RF, Garrett TJ, Cooper-DeHoff RM. Association of branched and aromatic amino acids levels with metabolic syndrome and impaired fasting glucose in hypertensive patients. Metab Syndr Relat Disord 2015; 13:195-202. [PMID: 25664967 DOI: 10.1089/met.2014.0132] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND The three branched amino acids (valine, leucine, and isoleucine) and two aromatic amino acids (tyrosine and phenylalanine) have been associated with many adverse metabolic pathways, including diabetes. However, these associations have been identified primarily in otherwise healthy Caucasian populations. We aimed to investigate the association of this five-amino-acid signature with metabolic syndrome and impaired fasting glucose (IFG) in a hypertensive cohort of Caucasian and African Americans. METHODS We analyzed data from the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) studies PEAR and PEAR2 conducted between 2005 and 2014. Subjects were enrolled at the University of Florida (Gainesville, FL), Emory University (Atlanta, GA), and Mayo Clinic (Rochester, MN). A total of 898 patients with essential hypertension were included in this study. Presence of metabolic syndrome and IFG at baseline were determined on the basis of measurements of demographic and biochemical data. Levels of the five amino acids were quantified by liquid chromatography-tandem mass spectroscopy (LC-MS/MS). RESULTS With a multiple logistic regression model, we found that all five amino acids were significantly associated with metabolic syndrome in both Caucasian and African Americans. IFG and the five amino acids were associated in the Caucasian Americans. Only valine was significantly associated with IFG in African Americans. CONCLUSION In both Caucasian and African Americans with uncomplicated hypertension, plasma levels of the five-amino-acid signature are associated with metabolic syndrome. Additionally, in Caucasians we have confirmed the five-amino-acid signature was associated with IFG.
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Affiliation(s)
- Liming Weng
- 1 Department of Pharmacotherapy and Translational Research and Center for Pharmacogenomics, University of Florida , College of Pharmacy, Gainesville, Florida
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Chen R, Zou Y, Mao D, Sun D, Gao G, Shi J, Liu X, Zhu C, Yang M, Ye W, Hao Q, Li R, Yu L. The general amino acid control pathway regulates mTOR and autophagy during serum/glutamine starvation. ACTA ACUST UNITED AC 2014; 206:173-82. [PMID: 25049270 PMCID: PMC4107793 DOI: 10.1083/jcb.201403009] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Organisms have evolved elaborate mechanisms to adjust intracellular nutrient levels in response to fluctuating availability of exogenous nutrients. During starvation, cells can enhance amino acid uptake and synthesis through the general amino acid control (GAAC) pathway, whereas nonessential cellular contents are recycled by autophagy. How these two pathways are coordinated in response to starvation is currently unknown. Here we show that the GAAC pathway couples exogenous amino acid availability with autophagy. Starvation caused deactivation of mTOR, which then activated autophagy. In parallel, serum/glutamine starvation activated the GAAC pathway, which up-regulated amino acid transporters, leading to increased amino acid uptake. This elevated the intracellular amino acid level, which in turn reactivated mTOR and suppressed autophagy. Knockdown of activating transcription factor 4, the major transcription factor in the GAAC pathway, or of SLC7A5, a leucine transporter, caused impaired mTOR reactivation and much higher levels of autophagy. Thus, the GAAC pathway modulates autophagy by regulating amino acid uptake and mTOR reactivation during serum/glutamine starvation.
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Affiliation(s)
- Rui Chen
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yilong Zou
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Dongxue Mao
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Daxiao Sun
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Guanguang Gao
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jingwen Shi
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaoqing Liu
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Chen Zhu
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Mingyu Yang
- Biodynamics Optical Imaging Center, Peking University, Beijing 100871, China
| | - Wanlu Ye
- Biodynamics Optical Imaging Center, Peking University, Beijing 100871, China
| | - Qianqian Hao
- Beijing Amino Medical Research Company, Beijing 100084, China
| | - Ruiqiang Li
- Biodynamics Optical Imaging Center, Peking University, Beijing 100871, China
| | - Li Yu
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
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Klein MS, Connors KE, Shearer J, Vogel HJ, Hittel DS. Metabolomics reveals the sex-specific effects of the SORT1 low-density lipoprotein cholesterol locus in healthy young adults. J Proteome Res 2014; 13:5063-70. [PMID: 25182463 DOI: 10.1021/pr500659r] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Metabolite profiles of individuals possessing either the cardiovascular risk or protective variants of the low-density lipoprotein cholesterol (LDL-C) associated 1p13.3 locus of the SORT1 gene (rs646776) were analyzed. Serum metabolites and lipids were assessed using LC-MS-based metabolomics in a healthy young population (n = 138: 95 males, 43 females). Although no significant differences were observed in the combined cohort, divergent sex effects were identified. Females carrying the protective allele showed increased phosphatidylcholines, very long chain fatty acids (>C20), and unsaturated fatty acids. Unsaturated fatty acids are considered to be protective against cardiovascular disease. In contrast, males carrying the protective allele exhibited decreased long-chain fatty acids (≤C20) and sphingomyelins, which is similarly considered to decrease cardiovascular disease risk. No significant changes in clinically assessed lipids such as LDL-C, high-density lipoprotein (HDL-C), total cholesterol, or triglycerides were observed in females, whereas only LDL-C was significantly changed in males. This indicates that, apart from reducing LDL-C, other mechanisms may contribute to the protective effect of the SORT1 locus. Thus, the analysis of metabolic biomarkers might reveal early disease development that may be overlooked by relying on standard clinical parameters.
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Affiliation(s)
- Matthias S Klein
- Faculty of Kinesiology, ‡Department of Biochemistry and Molecular Biology, Faculty of Medicine, and §Department of Biological Sciences, University of Calgary , Calgary, Alberta T2N 1N4, Canada
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Xiao F, Yu J, Guo Y, Deng J, Li K, Du Y, Chen S, Zhu J, Sheng H, Guo F. Effects of individual branched-chain amino acids deprivation on insulin sensitivity and glucose metabolism in mice. Metabolism 2014; 63:841-50. [PMID: 24684822 DOI: 10.1016/j.metabol.2014.03.006] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 02/21/2014] [Accepted: 03/12/2014] [Indexed: 12/12/2022]
Abstract
OBJECTIVE We recently discovered that leucine deprivation increases hepatic insulin sensitivity via general control nondepressible (GCN) 2/mammalian target of rapamycin (mTOR) and AMP-activated protein kinase (AMPK) pathways. The goal of the present study was to investigate whether the above effects were leucine specific or were also induced by deficiency of other branched chain amino acids including valine and isoleucine. METHODS Following depletion of BCAAs, changes in metabolic parameters and the expression of genes and proteins involved in regulation of insulin sensitivity and glucose metabolism were analyzed in mice and cell lines including human HepG2 cells, primary mouse hepatocytes and a mouse myoblast cell line C2C12. RESULTS Valine or isoleucine deprivation for 7 days has similar effect on improving insulin sensitivity as leucine, in wild type and insulin-resistant mice models. These effects are possibly mediated by decreased mTOR/S6K1 and increased AMPK signaling pathways, in a GCN2-dependent manner. Similar observations were obtained in in vitro studies. In contrast to leucine withdrawal, valine or isoleucine deprivation for 7 days significantly decreased fed blood glucose levels, possibly due to reduced expression of a key gluconeogenesis gene, glucose-6-phosphatase. Finally, insulin sensitivity was rapidly improved in mice 1 day following maintenance on a diet deficient for any individual BCAAs. CONCLUSIONS Our results show that while improvement on insulin sensitivity is a general feature of BCAAs depletion, individual BCAAs have specific effects on metabolic pathways, including those that regulate glucose level. These observations provide a conceptual framework for delineating the molecular mechanisms that underlie amino acid regulation of insulin sensitivity.
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Affiliation(s)
- Fei Xiao
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, the Graduate School of the Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, China 200031.
| | - Junjie Yu
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, the Graduate School of the Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, China 200031.
| | - Yajie Guo
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, the Graduate School of the Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, China 200031.
| | - Jiali Deng
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, the Graduate School of the Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, China 200031.
| | - Kai Li
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, the Graduate School of the Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, China 200031.
| | - Ying Du
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, the Graduate School of the Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, China 200031.
| | - Shanghai Chen
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, the Graduate School of the Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, China 200031.
| | - Jianmin Zhu
- Shanghai Xuhui Central Hospital, 966 Huaihai Middle Road, Shanghai, China 200030.
| | - Hongguang Sheng
- Shanghai Xuhui Central Hospital, 966 Huaihai Middle Road, Shanghai, China 200030.
| | - Feifan Guo
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, the Graduate School of the Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, China 200031.
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50
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Averous J, Lambert-Langlais S, Carraro V, Gourbeyre O, Parry L, B'Chir W, Muranishi Y, Jousse C, Bruhat A, Maurin AC, Proud CG, Fafournoux P. Requirement for lysosomal localization of mTOR for its activation differs between leucine and other amino acids. Cell Signal 2014; 26:1918-27. [PMID: 24793303 DOI: 10.1016/j.cellsig.2014.04.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 04/27/2014] [Indexed: 11/17/2022]
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) is a master regulator of cell growth and metabolism. It controls many cell functions by integrating nutrient availability and growth factor signals. Amino acids, and in particular leucine, are among the main positive regulators of mTORC1 signaling. The current model for the regulation of mTORC1 by amino acids involves the movement of mTOR to the lysosome mediated by the Rag-GTPases. Here, we have examined the control of mTORC1 signaling and mTOR localization by amino acids and leucine in serum-fed cells, because both serum growth factors (or, e.g., insulin) and amino acids are required for full activation of mTORC1 signaling. We demonstrate that mTORC1 activity does not closely correlate with the lysosomal localization of mTOR. In particular, leucine controls mTORC1 activity without any detectable modification of the lysosomal localization of mTOR, indicating that the signal(s) exerted by leucine is likely distinct from those exerted by other amino acids. In addition, knock-down of the Rag-GTPases attenuated the inhibitory effect of amino acid- or leucine-starvation on the phosphorylation of mTORC1 targets. Furthermore, data from cells where Rag expression has been knocked down revealed that leucine can promote mTORC1 signaling independently of the lysosomal localization of mTOR. Our data complement existing models for the regulation of mTORC1 by amino acids and provide new insights into this important topic.
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Affiliation(s)
- Julien Averous
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France.
| | - Sarah Lambert-Langlais
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Valérie Carraro
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Ophélie Gourbeyre
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Laurent Parry
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Wafa B'Chir
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Yuki Muranishi
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Céline Jousse
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Alain Bruhat
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Anne-Catherine Maurin
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Christopher G Proud
- Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Pierre Fafournoux
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France.
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