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Elshorbagy AK, Nijpels G, Valdivia-Garcia M, Stehouwer CDA, Ocke M, Refsum H, Dekker JM. S-adenosylmethionine is associated with fat mass and truncal adiposity in older adults. J Nutr 2013; 143:1982-8. [PMID: 24068793 DOI: 10.3945/jn.113.179192] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
S-adenosylmethionine (SAM) is synthesized from methionine, which is abundant in animal-derived protein, in an energy-consuming reaction. SAM and S-adenosylhomocysteine (SAH) correlate with body mass index (BMI). Plasma total concentration of the SAM-associated product cysteine (tCys) correlates with fat mass in humans and cysteine promotes adiposity in animals. In a cross-sectional study of 610 participants, we investigated whether SAM and SAH are associated with BMI via lean mass or fat mass and dietary protein sources as determinants of SAM and tCys concentrations. Plasma SAM was not associated with lean mass, but mean adjusted fat mass increased from 24 kg (95% CI: 22.6, 25.1) to 30 kg (95% CI: 28.7, 31.3) across SAM quartiles (P < 0.001) and trunk fat:total fat ratio increased from 0.48 to 0.52 (P < 0.001). Erythrocyte SAM was also positively associated with fat mass and trunk fat:total fat ratio. The association of SAM with fat mass was not weakened by adjustment for serum tCys, lipids, creatinine, or dietary or lifestyle confounders. Concentrations of the SAM precursor, methionine, and the SAM product, SAH, were not independently associated with adiposity. Intake of animal-derived protein was not related to serum methionine but was positively associated with plasma SAM (partial r = 0.11) and serum tCys (partial r = 0.13; P < 0.05 for both after adjustment for age, gender, and total energy intake). In conclusion, plasma SAM, but not methionine, is independently associated with fat mass and truncal adiposity, suggesting increased conversion of methionine to SAM in obese individuals. Prospective studies are needed to investigate the interactions among dietary energy and animal protein content, SAM concentrations, and change in body weight and cardiometabolic risk.
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102
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Malloy VL, Perrone CE, Mattocks DAL, Ables GP, Caliendo NS, Orentreich DS, Orentreich N. Methionine restriction prevents the progression of hepatic steatosis in leptin-deficient obese mice. Metabolism 2013; 62:1651-61. [PMID: 23928105 DOI: 10.1016/j.metabol.2013.06.012] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 05/30/2013] [Accepted: 06/27/2013] [Indexed: 12/14/2022]
Abstract
OBJECTIVE This study investigated the effects of dietary methionine restriction (MR) on the progression of established hepatic steatosis in the leptin-deficient ob/ob mouse. MATERIAL/METHODS Ten-week-old ob/ob mice were fed diets containing 0.86% (control-fed; CF) or 0.12% methionine (MR) for 14 weeks. At 14 weeks, liver and fat were excised and blood was collected for analysis. In another study, blood was collected to determine in vivo triglyceride (TG) and very-low-density lipoprotein (VLDL) secretion rates. Liver histology was conducted to determine the severity of steatosis. Hepatic TG, free fatty acid levels, and fatty acid oxidation (FAO) were also measured. Gene expression was analyzed by quantitative PCR. RESULTS MR reversed the severity of steatosis in the ob/ob mouse. This was accompanied by reduced body weight despite similar weight-specific food intake. Compared with the CF group, hepatic TG levels were significantly reduced in response to MR, but adipose tissue weight was not decreased. MR reduced insulin and HOMA ratios but increased total and high-molecular-weight adiponectin levels. Scd1 gene expression was significantly downregulated, while Acadvl, Hadha, and Hadhb were upregulated in MR, corresponding with increased β-hydroxybutyrate levels and a trend toward increased FAO. The VLDL secretion rate was also significantly increased in the MR mice, as were the mRNA levels of ApoB and Mttp. The expression of inflammatory markers, such as Tnf-α and Ccr2, was also downregulated by MR. CONCLUSIONS Our data indicate that MR reverses steatosis in the ob/ob mouse liver by promoting FAO, increasing the export of lipids, and reducing obesity-related inflammatory responses.
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Affiliation(s)
- Virginia L Malloy
- Orentreich Foundation for the Advancement of Science, Inc., 855 Route 301, Cold Spring-on-Hudson, NY 10516, USA.
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103
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Hasek BE, Boudreau A, Shin J, Feng D, Hulver M, Van NT, Laque A, Stewart LK, Stone KP, Wanders D, Ghosh S, Pessin JE, Gettys TW. Remodeling the integration of lipid metabolism between liver and adipose tissue by dietary methionine restriction in rats. Diabetes 2013; 62:3362-72. [PMID: 23801581 PMCID: PMC3781441 DOI: 10.2337/db13-0501] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Dietary methionine restriction (MR) produces an integrated series of biochemical and physiological responses that improve biomarkers of metabolic health, limit fat accretion, and enhance insulin sensitivity. Using transcriptional profiling to guide tissue-specific evaluations of molecular responses to MR, we report that liver and adipose tissue are the primary targets of a transcriptional program that remodeled lipid metabolism in each tissue. The MR diet produced a coordinated downregulation of lipogenic genes in the liver, resulting in a corresponding reduction in the capacity of the liver to synthesize and export lipid. In contrast, the transcriptional response in white adipose tissue (WAT) involved a depot-specific induction of lipogenic and oxidative genes and a commensurate increase in capacity to synthesize and oxidize fatty acids. These responses were accompanied by a significant change in adipocyte morphology, with the MR diet reducing cell size and increasing mitochondrial density across all depots. The coordinated transcriptional remodeling of lipid metabolism between liver and WAT by dietary MR produced an overall reduction in circulating and tissue lipids and provides a potential mechanism for the increase in metabolic flexibility and enhanced insulin sensitivity produced by the diet.
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Affiliation(s)
- Barbara E. Hasek
- Laboratories of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Anik Boudreau
- Laboratories of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Jeho Shin
- Laboratories of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Daorong Feng
- Departments of Medicine and Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York
| | - Matthew Hulver
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia
| | - Nancy T. Van
- Laboratories of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Amanda Laque
- Laboratories of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Laura K. Stewart
- Laboratories of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Kirsten P. Stone
- Laboratories of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Desiree Wanders
- Laboratories of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Sujoy Ghosh
- Laboratory of Computational Biology, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Jeffrey E. Pessin
- Departments of Medicine and Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York
| | - Thomas W. Gettys
- Laboratories of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana
- Corresponding author: Thomas W. Gettys,
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104
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Vinknes KJ, Dekker JM, Drevon CA, Refsum H, Nurk E, Nijpels G, Stehouwer CDA, Teerlink T, Tell GS, Nygård O, Vollset SE, Ueland PM, Elshorbagy AK. Plasma sulfur amino acids and stearoyl-CoA desaturase activity in two Caucasian populations. Prostaglandins Leukot Essent Fatty Acids 2013; 89:297-303. [PMID: 24120123 DOI: 10.1016/j.plefa.2013.09.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 09/04/2013] [Accepted: 09/09/2013] [Indexed: 12/29/2022]
Abstract
In rats, dietary restriction of the cysteine precursor methionine suppresses hepatic stearoyl-CoA desaturase (SCD)-1 expression and activity, whereas cysteine supplementation reverses these effects. In 2 independent cohorts: Hordaland Health Study (HUSK; N=2021, aged 71-74y), Norway, and Hoorn study (N=686, aged 50-87y), Netherlands, we examined the cross-sectional associations of plasma sulfur-containing compounds (SCC; methionine, S-adenosylmethionine, S-adenosylhomocysteine, homocysteine, cystathionine, total cysteine (tCys), glutathione and cysteinylglycine) with SCD-16 index (16:1n-7/16:0), estimated from fatty acid profiles of total plasma or serum lipids. Only tCys was consistently associated with SCD-16 index after adjustments for sex and age (HUSK: partial r=0.14; Hoorn: partial r=0.11, P<0.001 for both), and after further adjustments for other SCC, body fat, diet, exercise and plasma lipids (HUSK: partial r=0.07, P=0.004; Hoorn: partial r=0.12, P=0.013). Together with animal data showing an effect of dietary cysteine on SCD1, our results suggest a role for cysteine in SCD1 regulation in humans.
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Affiliation(s)
- K J Vinknes
- Department of Nutrition, Institute of Basic Medical Science, Faculty of Medicine, University of Oslo, Post box 1046 Blindern, 0317 Oslo, Norway.
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105
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Vinknes KJ, Elshorbagy AK, Drevon CA, Nurk E, Tell GS, Nygård O, Vollset SE, Refsum H. Associations between plasma polyunsaturated fatty acids, plasma stearoyl-CoA desaturase indices and body fat. Obesity (Silver Spring) 2013; 21:E512-9. [PMID: 23512934 DOI: 10.1002/oby.20457] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 03/07/2013] [Indexed: 11/05/2022]
Abstract
OBJECTIVE Stearoyl-CoA desaturase (SCD)-1 deficient mice are resistant to obesity and plasma SCD indices are related to obesity in humans. Both n-3 and n-6 polyunsaturated fatty acids (PUFA) regulate expression of the SCD enzymes. Whether higher plasma PUFA were associated with lower SCD indices in humans was examined. DESIGN AND METHODS Population-based study of 2,021 elderly subjects from the Hordaland Health Study. Using multivariate linear regression, the cross-sectional associations among plasma PUFA, estimated SCD indices (from fatty acid profiles in plasma total lipids), and fat mass measured by dual-energy X-ray absorptiometry were explored. Two plasma SCD indices were used: SCD-16 (16:1n-7/16:0) and SCD-18 (18:1n-9/18:0). RESULTS Plasma total, n-6 and n-3 PUFA were inversely associated with both SCD indices (P < 0.001 for all). Among the individual PUFA, 18:2n-6 showed the strongest association with SCD-16 (partial r = -0.59, P < 0.001) followed by 20:5n-3 (partial r = -0.13; P < 0.001). Plasma total, n-6 and n-3 PUFA were inversely associated with body fat (P < 0.001 for all); the associations were markedly attenuated following adjustment for SCD-16. CONCLUSIONS The epidemiological data are in line with animal studies and suggest that PUFA may decrease SCD1 activity in humans, with possible reduction in body fat.
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Affiliation(s)
- Kathrine J Vinknes
- Department of Nutrition, Institute of Basic Medical Science, Faculty of Medicine, University of Oslo, Oslo, Norway
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106
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Affiliation(s)
- Tracy G. Anthony
- Department of Nutritional Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| | | | - Thomas W. Gettys
- Laboratory of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana
- Corresponding author: Thomas W. Gettys,
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107
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Pissios P, Hong S, Kennedy AR, Prasad D, Liu FF, Maratos-Flier E. Methionine and choline regulate the metabolic phenotype of a ketogenic diet. Mol Metab 2013; 2:306-13. [PMID: 24049742 DOI: 10.1016/j.molmet.2013.07.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 07/01/2013] [Accepted: 07/03/2013] [Indexed: 01/02/2023] Open
Abstract
Low-carbohydrate ketogenic diets are commonly used as weight loss alternatives to low-fat diets, however the physiological and molecular adaptations to these diets are not completely understood. It is assumed that the metabolic phenotype of the ketogenic diet (KD) is caused by the absence of carbohydrate and high fat content, however in rodents the protein content of KD affects weight gain and ketosis. In this study we examined the role of methionine and choline in mediating the metabolic effects of KD. We have found that choline was more effective than methionine in decreasing the liver steatosis of KD-fed mice. On the other hand, methionine supplementation was more effective than choline in restoring weight gain and normalizing the expression of several fatty acid and inflammatory genes in the liver of KD-fed mice. Our results indicate that choline and methionine restriction rather than carbohydrate restriction underlies many of the metabolic effects of KD.
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Affiliation(s)
- Pavlos Pissios
- Division of Diabetes, Endocrinology and Metabolism, E/CLS-734, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA 02215, USA
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108
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Perrone CE, Malloy VL, Orentreich DS, Orentreich N. Metabolic adaptations to methionine restriction that benefit health and lifespan in rodents. Exp Gerontol 2013; 48:654-60. [DOI: 10.1016/j.exger.2012.07.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 07/09/2012] [Accepted: 07/10/2012] [Indexed: 01/05/2023]
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109
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Glier MB, Green TJ, Devlin AM. Methyl nutrients, DNA methylation, and cardiovascular disease. Mol Nutr Food Res 2013; 58:172-82. [PMID: 23661599 DOI: 10.1002/mnfr.201200636] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 03/08/2013] [Accepted: 03/13/2013] [Indexed: 12/22/2022]
Abstract
Diet plays an important role in the development and prevention of cardiovascular disease (CVD), but the molecular mechanisms are not fully understood. DNA methylation has been implicated as an underlying molecular mechanism that may account for the effect of dietary factors on the development and prevention of CVD. DNA methylation is an epigenetic process that provides "marks" in the genome by which genes are set to be transcriptionally activated or silenced. Epigenomic marks are heritable but are also responsive to environmental shifts, such as changes in nutritional status, and are especially vulnerable during development. S-adenosylmethionine is the methyl group donor for DNA methylation and several nutrients are required for the production of S-adenosylmethionine. These methyl nutrients include vitamins (folate, riboflavin, vitamin B12, vitamin B6, choline) and amino acids (methionine, cysteine, serine, glycine). As such, imbalances in the metabolism of these nutrients have the potential to affect DNA methylation. The focus of this review is to provide an overview on the current understanding of the relationship between methyl nutrient status and DNA methylation patterns and the potential role of this interaction in CVD pathology.
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Affiliation(s)
- Melissa B Glier
- Department of Pathology and Laboratory Medicine, Child and Family Research Institute, University of British Columbia, Vancouver, Canada
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110
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Elshorbagy AK, Valdivia-Garcia M, Mattocks DAL, Plummer JD, Orentreich DS, Orentreich N, Refsum H, Perrone CE. Effect of taurine and N-acetylcysteine on methionine restriction-mediated adiposity resistance. Metabolism 2013; 62:509-17. [PMID: 23154184 DOI: 10.1016/j.metabol.2012.10.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 09/07/2012] [Accepted: 10/09/2012] [Indexed: 12/16/2022]
Abstract
OBJECTIVES Methionine-restricted (MR) rats, which are lean and insulin sensitive, have low serum total cysteine (tCys) and taurine and decreased hepatic expression and activity indices of stearoyl-coenzyme A desaturase-1 (SCD1). These effects are partly or completely reversed by cysteine supplementation. We investigated whether reversal of MR phenotypes can be achieved by other sulfur compounds, namely taurine or N-acetylcysteine (NAC). METHODS MR and control-fed (CF) rats were supplemented with taurine (0.5%) or NAC (0.5%) for 12weeks. Adiposity, serum sulfur amino acids (SAA), Scd1 gene expression in liver and white adipose tissue, and SCD1 activity indices (calculated from serum fatty acid profile) were monitored. RESULTS Taurine supplementation of MR rats did not restore weight gain or hepatic Scd1 expression or indices to CF levels, but further decreased adiposity. Taurine supplementation of CF rats did not affect adiposity, but lowered triglyceridemia. NAC supplementation in MR rats raised tCys and partly or completely reversed MR effects on weight, fat %, Scd1 expression in liver and white adipose tissue, and estimated SCD1 activity. In CF rats, NAC decreased body fat % and lowered SCD1-18 activity index (P<0.001). Serum triglycerides and leptin were over 40% lower in CF+NAC relative to CF rats (P≤0.003 for both). In all groups, change in tCys correlated with change in SCD1-16 index (partial r=0.60, P<0.001) independent of other SAA. CONCLUSION The results rule out taurine as a mediator of increased adiposity produced by cysteine in MR, and show that NAC, similar to L-cysteine, blocks anti-obesity effects of MR. Our data show that dietary SAA can influence adiposity in part through mechanisms that converge on SCD1 function. This may have implications for understanding and preventing human obesity.
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111
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Vinknes KJ, Elshorbagy AK, Nurk E, Drevon CA, Gjesdal CG, Tell GS, Nygård O, Vollset SE, Refsum H. Plasma stearoyl-CoA desaturase indices: association with lifestyle, diet, and body composition. Obesity (Silver Spring) 2013; 21:E294-302. [PMID: 23404690 DOI: 10.1002/oby.20011] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 06/04/2012] [Indexed: 11/07/2022]
Abstract
OBJECTIVE Stearoyl-coenzyme A desaturase-1 (SCD1) is a key enzyme in fatty acid and energy metabolism. Increased hepatic SCD1 activity is associated with obesity and obesity-related diseases. We examined the relations of two plasma SCD activity indices (16:1n-7/16:0, 18:1n-9/18:0) with body composition, and the association of lifestyle and dietary variables with the plasma SCD indices. DESIGN AND METHODS This population-based, cross-sectional study of 2021 elderly (71-74 y) men and women from the Hordaland Health Study in Western Norway was conducted using a validated food frequency questionnaire, body composition measurements by dual-energy X-ray absorptiometry and determination of the plasma fatty acid profile. RESULTS In multivariate regression analyses, plasma SCD indices were positively associated with BMI and body fat (P < 0.001 for both). From the 2.5th to 97.5th percentiles of plasma SCD-16 and SCD-18 indices, fat mass differed by about 8 kg and 5 kg, respectively. Intake of polyunsaturated fatty acids were negatively associated with SCD-16 (partial r = -0.30) and SCD-18 (partial r = -0.24) (P < 0.001 for both). Alcohol intake was positively associated with SCD-16 (partial r = 0.26) and SCD-18 (partial r = 0.16) (P < 0.001 for both), whereas coffee consumption and physical activity were inversely associated with SCD-16 (P = 0.026 and P = 0.006, respectively) and SCD-18 (P = 0.001 and P = 0.022, respectively). CONCLUSIONS In this elderly population, plasma markers of SCD1 activity are associated with increased adiposity. Furthermore, modifiable dietary habits and lifestyle are associated with plasma SCD indices. These results suggest that SCD1 activity may be a promising target for weight control.
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Affiliation(s)
- Kathrine J Vinknes
- Department of Nutrition, Institute of Basic Medical Science, Faculty of Medicine, University of Oslo, Oslo, Norway.
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112
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Sanchez-Roman I, Barja G. Regulation of longevity and oxidative stress by nutritional interventions: role of methionine restriction. Exp Gerontol 2013; 48:1030-42. [PMID: 23454735 DOI: 10.1016/j.exger.2013.02.021] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 01/17/2013] [Accepted: 02/21/2013] [Indexed: 11/25/2022]
Abstract
Comparative studies indicate that long-lived mammals have low rates of mitochondrial reactive oxygen species production (mtROSp) and oxidative damage in their mitochondrial DNA (mtDNA). Dietary restriction (DR), around 40%, extends the mean and maximum life span of a wide range of species and lowers mtROSp and oxidative damage to mtDNA, which supports the mitochondrial free radical theory of aging (MFRTA). Regarding the dietary factor responsible for the life extension effect of DR, neither carbohydrate nor lipid restriction seems to modify maximum longevity. However protein restriction (PR) and methionine restriction (at least 80% MetR) increase maximum lifespan in rats and mice. Interestingly, only 7weeks of 40% PR (at least in liver) or 40% MetR (in all the studied organs, heart, brain, liver or kidney) is enough to decrease mtROSp and oxidative damage to mtDNA in rats, whereas neither carbohydrate nor lipid restriction changes these parameters. In addition, old rats also conserve the capacity to respond to 7weeks of 40% MetR with these beneficial changes. Most importantly, 40% MetR, differing from what happens during both 40% DR and 80% MetR, does not decrease growth rate and body size of rats. All the available studies suggest that the decrease in methionine ingestion that occurs during DR is responsible for part of the aging-delaying effect of this intervention likely through the decrease of mtROSp and ensuing DNA damage that it exerts. We conclude that lowering mtROS generation is a conserved mechanism, shared by long-lived species and dietary, protein, and methionine restricted animals, that decreases damage to macromolecules situated near the complex I mtROS generator, especially mtDNA. This would decrease the accumulation rate of somatic mutations in mtDNA and maybe finally also in nuclear DNA.
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Affiliation(s)
- Ines Sanchez-Roman
- Department of Animal Physiology-II, Faculty of Biological Sciences, Complutense University of Madrid (UCM), Spain
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113
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Del Vesco AP, Gasparino E, Oliveira Neto AR, Rossi RM, Soares MAM, da Silva SCC. Effect of methionine supplementation on mitochondrial genes expression in the breast muscle and liver of broilers. Livest Sci 2013. [DOI: 10.1016/j.livsci.2012.11.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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114
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Abstract
PURPOSE OF REVIEW To understand the principles of amino acid deprivation sensing in the brain and its behavioral and metabolic outcomes with an emphasis on the current literature. RECENT FINDINGS Sensing essential amino acid (EAA) depletion occurs in the anterior piriform cortex (APC) via general control nonderepressible 2 (GCN2) binding to deacylated tRNA and subsequent glutamatergic signaling to influence behavior. Mapping of the APC output during EAA insufficiency shows axons projecting to the hypothalamus as well as other regions that are involved in feeding and locomotion. Whereas these neurocircuits are clearly important in regulating anorectic responses to an EAA-devoid diet, the propagating events and regulatory factors are still unclear. Recently, several groups examined signaling and gene expression in the arcuate nucleus and lateral hypothalamus during EAA deficiency. In these efforts, several gene products, including somatostatin, corticotrophin-releasing hormone, neuropeptide Y, agouti-related protein, and several novel targets were identified as factors involved in regulating the aversion to EAA-deficient diets. On a different note, marginal EAA deficiency in the form of methionine restriction promotes hyperphagia similar to low-protein diets, yet animals are leaner and live longer. The central mechanisms are unclear but involve sympathetic nervous signaling. How and why different degrees of EAA deficiency cause opposite changes in behavior and body composition require further study. SUMMARY Scientific inquiry into the central mechanism by which EAA insufficiency is sensed has identified the APC as the brain's initial EAA chemosensor. Beyond this, much remains uncertain. Future investigation into the signaling and gene expression events occurring in the hypothalamus and other brain regions is warranted.
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Affiliation(s)
- Tracy G Anthony
- Department of Nutritional Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901, USA.
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115
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Ables GP, Perrone CE, Orentreich D, Orentreich N. Methionine-restricted C57BL/6J mice are resistant to diet-induced obesity and insulin resistance but have low bone density. PLoS One 2012; 7:e51357. [PMID: 23236485 PMCID: PMC3518083 DOI: 10.1371/journal.pone.0051357] [Citation(s) in RCA: 164] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 11/05/2012] [Indexed: 12/27/2022] Open
Abstract
Dietary methionine restriction (MR) extends lifespan, an effect associated with reduction of body weight gain, and improvement of insulin sensitivity in mice and rats as a result of metabolic adaptations in liver, adipose tissue and skeletal muscle. To test whether MR confers resistance to adiposity and insulin resistance, C57BL/6J mice were fed a high fat diet (HFD) containing either 0.86% methionine (control fed; CF) or 0.12% methionine (methionine-restricted; MR). MR mice on HFD had lower body weight gain despite increased food intake and absorption efficiency compared to their CF counterparts. MR mice on HFD were more glucose tolerant and insulin sensitive with reduced accumulation of hepatic triglycerides. In plasma, MR mice on HFD had higher levels of adiponectin and FGF21 while leptin and IGF-1 levels were reduced. Hepatic gene expression showed the downregulation of Scd1 while Pparg, Atgl, Cd36, Jak2 and Fgf21 were upregulated in MR mice on HFD. Restriction of growth rate in MR mice on HFD was also associated with lower bone mass and increased plasma levels of the collagen degradation marker C-terminal telopeptide of type 1 collagen (CTX-1). It is concluded that MR mice on HFD are metabolically healthy compared to CF mice on HFD but have decreased bone mass. These effects could be associated with the observed increase in FGF21 levels.
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Affiliation(s)
- Gene P Ables
- Orentreich Foundation for the Advancement of Science, Cold Spring-on-Hudson, New York, United States of America.
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116
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Norheim F, Gjelstad IMF, Hjorth M, Vinknes KJ, Langleite TM, Holen T, Jensen J, Dalen KT, Karlsen AS, Kielland A, Rustan AC, Drevon CA. Molecular nutrition research: the modern way of performing nutritional science. Nutrients 2012. [PMID: 23208524 PMCID: PMC3546614 DOI: 10.3390/nu4121898] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
In spite of amazing progress in food supply and nutritional science, and a striking increase in life expectancy of approximately 2.5 months per year in many countries during the previous 150 years, modern nutritional research has a great potential of still contributing to improved health for future generations, granted that the revolutions in molecular and systems technologies are applied to nutritional questions. Descriptive and mechanistic studies using state of the art epidemiology, food intake registration, genomics with single nucleotide polymorphisms (SNPs) and epigenomics, transcriptomics, proteomics, metabolomics, advanced biostatistics, imaging, calorimetry, cell biology, challenge tests (meals, exercise, etc.), and integration of all data by systems biology, will provide insight on a much higher level than today in a field we may name molecular nutrition research. To take advantage of all the new technologies scientists should develop international collaboration and gather data in large open access databases like the suggested Nutritional Phenotype database (dbNP). This collaboration will promote standardization of procedures (SOP), and provide a possibility to use collected data in future research projects. The ultimate goals of future nutritional research are to understand the detailed mechanisms of action for how nutrients/foods interact with the body and thereby enhance health and treat diet-related diseases.
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Affiliation(s)
- Frode Norheim
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, P.O. Box 1046, Blindern, N-0317 Oslo, Norway; (F.N.); (I.M.F.G.); (M.H.); (K.J.V.); (T.M.L.); (T.H.); (K.T.D.); (A.S.K.); (A.K.)
| | - Ingrid M. F. Gjelstad
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, P.O. Box 1046, Blindern, N-0317 Oslo, Norway; (F.N.); (I.M.F.G.); (M.H.); (K.J.V.); (T.M.L.); (T.H.); (K.T.D.); (A.S.K.); (A.K.)
| | - Marit Hjorth
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, P.O. Box 1046, Blindern, N-0317 Oslo, Norway; (F.N.); (I.M.F.G.); (M.H.); (K.J.V.); (T.M.L.); (T.H.); (K.T.D.); (A.S.K.); (A.K.)
| | - Kathrine J. Vinknes
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, P.O. Box 1046, Blindern, N-0317 Oslo, Norway; (F.N.); (I.M.F.G.); (M.H.); (K.J.V.); (T.M.L.); (T.H.); (K.T.D.); (A.S.K.); (A.K.)
| | - Torgrim M. Langleite
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, P.O. Box 1046, Blindern, N-0317 Oslo, Norway; (F.N.); (I.M.F.G.); (M.H.); (K.J.V.); (T.M.L.); (T.H.); (K.T.D.); (A.S.K.); (A.K.)
| | - Torgeir Holen
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, P.O. Box 1046, Blindern, N-0317 Oslo, Norway; (F.N.); (I.M.F.G.); (M.H.); (K.J.V.); (T.M.L.); (T.H.); (K.T.D.); (A.S.K.); (A.K.)
| | - Jørgen Jensen
- Department of Physical Performance, Norwegian School of Sport Science, P.O. Box 4014, Ullevål Stadion, N-0806 Oslo, Norway; Jorgen.
| | - Knut Tomas Dalen
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, P.O. Box 1046, Blindern, N-0317 Oslo, Norway; (F.N.); (I.M.F.G.); (M.H.); (K.J.V.); (T.M.L.); (T.H.); (K.T.D.); (A.S.K.); (A.K.)
| | - Anette S. Karlsen
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, P.O. Box 1046, Blindern, N-0317 Oslo, Norway; (F.N.); (I.M.F.G.); (M.H.); (K.J.V.); (T.M.L.); (T.H.); (K.T.D.); (A.S.K.); (A.K.)
| | - Anders Kielland
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, P.O. Box 1046, Blindern, N-0317 Oslo, Norway; (F.N.); (I.M.F.G.); (M.H.); (K.J.V.); (T.M.L.); (T.H.); (K.T.D.); (A.S.K.); (A.K.)
| | - Arild C. Rustan
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, P.O. Box 1068, Blindern, N-0316 Oslo, Norway;
| | - Christian A. Drevon
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, P.O. Box 1046, Blindern, N-0317 Oslo, Norway; (F.N.); (I.M.F.G.); (M.H.); (K.J.V.); (T.M.L.); (T.H.); (K.T.D.); (A.S.K.); (A.K.)
- Author to whom correspondence should be addressed; ; Tel.: +47-22851392; Fax: +47-22851393
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Elshorbagy AK, Valdivia-Garcia M, Graham IM, Palma Reis R, Sales Luis A, Smith AD, Refsum H. The association of fasting plasma sulfur-containing compounds with BMI, serum lipids and apolipoproteins. Nutr Metab Cardiovasc Dis 2012; 22:1031-1038. [PMID: 21550220 DOI: 10.1016/j.numecd.2011.01.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 11/27/2010] [Accepted: 01/04/2011] [Indexed: 01/08/2023]
Abstract
BACKGROUND AND AIM Sulfur amino acids are recognized as potent modulators of lipid metabolism. Plasma total cysteine (tCys) is associated with fat mass, obesity and serum LDL-cholesterol and apolipoprotein (Apo)-B in large population studies. It is not known how fasting plasma concentrations of cysteine precursors and products relate to these associations in humans, given that sulfur-containing compounds (SCC) influence rodent weight gain and serum lipids. METHODS AND RESULTS We investigated the cross-sectional associations of fasting plasma SCC (methionine, total homocysteine, cystathionine, tCys, taurine and total glutathione) with BMI and fasting serum lipids and apolipoproteins in 854 men and women with and without cardiovascular disease (CVD). In multiple linear regression analysis adjusted for age, gender, CVD and other SCC, neither methionine, taurine, nor total glutathione was associated with BMI. Plasma taurine was, however, inversely related to HDL-cholesterol (partial r = -0.12, p = 0.004) and its associated apoA1 (partial r = -0.18, p < 0.001). Plasma cystathionine correlated positively with triglycerides and BMI, while tCys positively correlated with total cholesterol, LDL-cholesterol (partial r = 0.20, p < 0.001) and its associated apoB. The associations of SCC with serum lipids were independent of BMI. tCys was also independently associated with BMI (partial r = 0.20, p < 0.001) after adjustment for other SCC, glucose, lipids and apolipoproteins. CONCLUSIONS Fasting tCys is associated with BMI independently of metabolically related SCC. Elevation of plasma SCC is generally associated with an unfavorable lipid profile. The negative relations of plasma taurine with HDL-C and apoA1 deserve further investigation.
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Perrone CE, Mattocks DAL, Plummer JD, Chittur SV, Mohney R, Vignola K, Orentreich DS, Orentreich N. Genomic and metabolic responses to methionine-restricted and methionine-restricted, cysteine-supplemented diets in Fischer 344 rat inguinal adipose tissue, liver and quadriceps muscle. JOURNAL OF NUTRIGENETICS AND NUTRIGENOMICS 2012; 5:132-57. [PMID: 23052097 DOI: 10.1159/000339347] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Accepted: 05/04/2012] [Indexed: 01/26/2023]
Abstract
BACKGROUND/AIMS Methionine restriction (MR) is a dietary intervention that increases lifespan, reduces adiposity and improves insulin sensitivity. These effects are reversed by supplementation of the MR diet with cysteine (MRC). Genomic and metabolomic studies were conducted to identify potential mechanisms by which MR induces favorable metabolic effects, and that are reversed by cysteine supplementation. METHODS Gene expression was examined by microarray analysis and TaqMan quantitative PCR. Levels of selected proteins were measured by Western blot and metabolic intermediates were analyzed by mass spectrometry. RESULTS MR increased lipid metabolism in inguinal adipose tissue and quadriceps muscle while it decreased lipid synthesis in liver. In inguinal adipose tissue, MR not only caused the transcriptional upregulation of genes associated with fatty acid synthesis but also of Lpin1, Pc, Pck1 and Pdk1, genes that are associated with glyceroneogenesis. MR also upregulated lipolysis-associated genes in inguinal fat and led to increased oxidation in this tissue, as suggested by higher levels of methionine sulfoxide and 13-HODE + 9-HODE compared to control-fed (CF) rats. Moreover, MR caused a trend toward the downregulation of inflammation-associated genes in inguinal adipose tissue. MRC reversed most gene and metabolite changes induced by MR in inguinal adipose tissue, but drove the expression of Elovl6, Lpin1, Pc, and Pdk1 below CF levels. In liver, MR decreased levels of a number of long-chain fatty acids, glycerol and glycerol-3-phosphate corresponding with the gene expression data. Although MR increased the expression of genes associated with carbohydrate metabolism, levels of glycolytic intermediates were below CF levels. MR, however, stimulated gluconeogenesis and ketogenesis in liver tissue. As previously reported, sulfur amino acids derived from methionine were decreased in liver by MR, but homocysteine levels were elevated. Increased liver homocysteine levels by MR were associated with decreased cystathionine β-synthase (CBS) protein levels and lowered vitamin B6 and 5-methyltetrahydrofolate (5MeTHF) content. Finally, MR upregulated fibroblast growth factor 21 (FGF21) gene and protein levels in both liver and adipose tissues. MRC reversed some of MR's effects in liver and upregulated the transcription of genes associated with inflammation and carcinogenesis such as Cxcl16, Cdh17, Mmp12, Mybl1, and Cav1 among others. In quadriceps muscle, MR upregulated lipid metabolism-associated genes and increased 3-hydroxybutyrate levels suggesting increased fatty acid oxidation as well as stimulation of gluconeogenesis and glycogenolysis in this tissue. CONCLUSION Increased lipid metabolism in inguinal adipose tissue and quadriceps muscle, decreased triglyceride synthesis in liver and the downregulation of inflammation-associated genes are among the factors that could favor the lean phenotype and increased insulin sensitivity observed in MR rats.
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Affiliation(s)
- Carmen E Perrone
- Orentreich Foundation for the Advancement of Science, Inc, Cold Spring-on-Hudson, NY, USA.
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Elshorbagy AK, Valdivia-Garcia M, Refsum H, Butte N. The association of cysteine with obesity, inflammatory cytokines and insulin resistance in Hispanic children and adolescents. PLoS One 2012; 7:e44166. [PMID: 22984471 PMCID: PMC3439485 DOI: 10.1371/journal.pone.0044166] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 07/30/2012] [Indexed: 01/11/2023] Open
Abstract
Context Plasma total cysteine (tCys) independently relates to fat mass in adults. Dietary cyst(e)ine promotes adiposity and decreases glucose tolerance in some rodent models, but alleviates insulin resistance in others. Objective To investigate whether the association of tCys with body fat extends to children at particular risk of obesity, and whether tCys is associated with insulin resistance and obesity-associated inflammation. Methods We explored the cross-sectional relations of fasting plasma tCys and related metabolites with body composition measured by dual-energy X-ray absorptiometry in 984 Hispanic children and adolescents aged 4–19 years from the Viva La Familia Study. Linear and logistic regression and dose-response curves were used to evaluate relations of tCys with obesity, insulin resistance and inflammatory markers including interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1) and C-reactive protein (CRP). Results tCys, methionine and total homocysteine (tHcy) increased with age. Upper tCys quartile was independently associated with a 5-fold increased risk of obesity (95% CI 3.5–8.0, P<0.001), and 2-fold risk of insulin resistance (95% CI: 1.6-5.0, P<0.001; adjusted for body fat%). Within the overweight/obese subgroup, but not in normal-weight children, tCys accounted for 9% of the variability in body fat% (partial r = 0.30, P<0.001; adjusted for age and gender). tCys correlated positively with serum non-esterified fatty acids and leptin, partly independent of body fat, but was not associated with serum IL-6, TNF-α or MCP-1. A positive correlation with CRP disappeared after adjustment for BMI. Conclusion tCys is independently associated with obesity and insulin resistance in Hispanic children and adolescents, highlighting a previously underappreciated link between the sulfur amino acid metabolic pathway and obesity and cardiometabolic risk.
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Affiliation(s)
- Amany K Elshorbagy
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom.
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Update on pparγ and nonalcoholic Fatty liver disease. PPAR Res 2012; 2012:912351. [PMID: 22966224 PMCID: PMC3431124 DOI: 10.1155/2012/912351] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 07/16/2012] [Indexed: 12/23/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common initial presentation of obesity and insulin resistance. Uninterrupted progression of hepatic lipid accumulation often leads to fatty liver disease and eventually cirrhosis. Insulin resistance is one of the characteristics of type 2 diabetes. Several types of treatment have been employed against type 2 diabetes some of which ameliorate NAFLD. The frequent line of treatment to improve insulin sensitivity is the use of thiazolidinediones (TZD) which activate the nuclear receptor, peroxisome proliferator activated receptor gamma (Pparγ). Although TZDs are proven to be very effective in promoting insulin sensitivity, its actions on Pparγ have been complicated, specifically on NAFLD. According to studies in different models, Pparγ manifests both beneficial and undesirable effects on NAFLD. This paper will focus on the current knowledge of Pparγ and its effect on NAFLD.
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The brain's response to an essential amino acid-deficient diet and the circuitous route to a better meal. Mol Neurobiol 2012; 46:332-48. [PMID: 22674217 DOI: 10.1007/s12035-012-8283-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 05/24/2012] [Indexed: 12/16/2022]
Abstract
The essential (indispensable) amino acids (IAA) are neither synthesized nor stored in metazoans, yet they are the building blocks of protein. Survival depends on availability of these protein precursors, which must be obtained in the diet; it follows that food selection is critical for IAA homeostasis. If even one of the IAA is depleted, its tRNA becomes quickly deacylated and the levels of charged tRNA fall, leading to disruption of global protein synthesis. As they have priority in the diet, second only to energy, the missing IAA must be restored promptly or protein catabolism ensues. Animals detect and reject an IAA-deficient meal in 20 min, but how? Here, we review the molecular basis for sensing IAA depletion and repletion in the brain's IAA chemosensor, the anterior piriform cortex (APC). As animals stop eating an IAA-deficient meal, they display foraging and altered choice behaviors, to improve their chances of encountering a better food. Within 2 h, sensory cues are associated with IAA depletion or repletion, leading to learned aversions and preferences that support better food selection. We show neural projections from the APC to appetitive and consummatory motor control centers, and to hedonic, motivational brain areas that reinforce these adaptive behaviors.
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Elshorbagy AK, Kozich V, Smith AD, Refsum H. Cysteine and obesity: consistency of the evidence across epidemiologic, animal and cellular studies. Curr Opin Clin Nutr Metab Care 2012; 15:49-57. [PMID: 22108094 DOI: 10.1097/mco.0b013e32834d199f] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW The concentrations of several plasma amino acids increase in obesity. Notably, plasma total concentrations of the sulphur amino acid cysteine (tCys) are linearly associated with fat mass in large population studies. Animal and cellular experiments support the concept that cysteine may be obesogenic. Here we review experimental and epidemiologic findings linking cysteine and related compounds with fat regulation and obesity. RECENT FINDINGS tCys, and to a lesser extent cystathionine, are the only plasma sulphur amino acids consistently associated with human obesity, whereas glutathione is inversely associated with BMI. Supplementing cyste(i)ne in rodents decreases energy expenditure and promotes adiposity, whereas defects of cysteine-synthesizing enzymes decrease body weight. In adipocytes, cysteine inhibits lipolysis and promotes lipogenesis via H2O2 production. Unlike most plasma amino acids, tCys levels do not decrease with gastric bypass-induced weight loss, further supporting the concept that elevated cysteine may be a cause, not a consequence of obesity. Although cysteine products (glutathione, taurine and H2S) are altered in obesity, they do not appear to explain cysteine's effects on body weight. SUMMARY Cellular, animal and epidemiologic data are consistent with the view that cysteine is obesogenic. Targeted research linking in-vitro and in-vivo findings is needed to elucidate mechanisms involved.
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Gupta S, Kruger WD. Cystathionine beta-synthase deficiency causes fat loss in mice. PLoS One 2011; 6:e27598. [PMID: 22096601 PMCID: PMC3214081 DOI: 10.1371/journal.pone.0027598] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Accepted: 10/20/2011] [Indexed: 12/19/2022] Open
Abstract
Cystathionine beta synthase (CBS) is the rate-limiting enzyme responsible for the de novo synthesis of cysteine. Patients with CBS deficiency have greatly elevated plasma total homocysteine (tHcy), decreased levels of plasma total cysteine (tCys), and often a marfanoid appearance characterized by thinness and low body-mass index (BMI). Here, we characterize the growth and body mass characteristics of CBS deficient TgI278T Cbs−/− mice and show that these animals have significantly decreased fat mass and tCys compared to heterozygous sibling mice. The decrease in fat mass is accompanied by a 34% decrease in liver glutathione (GSH) along with a significant decrease in liver mRNA and protein for the critical fat biosynthesizing enzyme Stearoyl CoA desaturase-1 (Scd-1). Because plasma tCys has been positively associated with fat mass in humans, we tested the hypothesis that decreased tCys in TgI278T Cbs−/− mice was the cause of the lean phenotype by placing the animals on water supplemented with N-acetyl cysteine (NAC) from birth to 240 days of age. Although NAC treatment in TgI278T Cbs−/− mice caused significant increase in serum tCys and liver GSH, there was no increase in body fat content or in liver Scd-1 levels. Our results show that lack of CBS activity causes loss of fat mass, and that this effect appears to be independent of low serum tCys.
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Affiliation(s)
- Sapna Gupta
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
| | - Warren D. Kruger
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Abstract
Plasma total cysteine (tCys) concentrations are associated with BMI. To study the relationship between tCys and BMI, we monitored the changes in serum concentrations of tCys and metabolically related compounds in sixty obese patients (BMI 50–60 kg/m2) from before to 1 year after either gastric bypass surgery (mean 30 % weight loss) or duodenal switch surgery (mean 41 % weight loss). A total of fifty-eight healthy persons (BMI 17–31 kg/m2) served as controls. Before surgery, obese patients had modestly (approximately 17 %) higher mean serum tCys, and markedly (>2-fold) higher glutamate concentrations, than controls (P ≤ 0·001 for both). Serial examinations after surgery revealed that gastric bypass patients had no change in tCys concentrations (P = 0·22), while duodenal switch patients showed a modest (approximately 12 %) but significant decrease in tCys (P < 0·001). Total homocysteine concentrations increased in duodenal switch patients but not in gastric bypass patients. Independent of surgery type, serum concentrations of methionine and cystathionine decreased (P < 0·05 for both), while serum glutathione and taurine remained stable. Glutamate concentrations declined, as did γ-glutamyltransferase activity (P < 0·001 for both). These results show that despite 30 % weight loss, and decreases in methionine, cystathionine and glutamate, there was no significant change in serum tCys in patients after gastric bypass surgery. The decrease in tCys in patients undergoing duodenal switch could be related to malabsorption. The present findings do not suggest that BMI is a causal determinant of plasma tCys.
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Elshorbagy AK, Church C, Valdivia-Garcia M, Smith AD, Refsum H, Cox R. Dietary cystine level affects metabolic rate and glycaemic control in adult mice. J Nutr Biochem 2011; 23:332-40. [PMID: 21543215 PMCID: PMC3315011 DOI: 10.1016/j.jnutbio.2010.12.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 12/08/2010] [Accepted: 12/22/2010] [Indexed: 12/18/2022]
Abstract
Plasma total cysteine (tCys) is strongly and independently associated with obesity in large human cohorts, but whether the association is causal is unknown. Dietary cyst(e)ine increases weight gain in some rodent models. We investigated the body composition, metabolic rate and metabolic phenotype of mature C3H/HeH mice assigned to low-cystine (LC) or high-cystine (HC) diets for 12 weeks. Compared to LC mice, HC mice gained more weight (P=.004 for 12-week weight gain %), with increased fat mass and lean mass, and lowered O2 consumption and CO2 production by calorimetry. The HC mice had 30% increase in intestinal fat/body weight % (P=.003) and ∼twofold elevated hepatic triglycerides (P=.046), with increased expression of hepatic lipogenic factors, peroxisome proliferator-activated receptor-γ and sterol regulatory element binding protein-1. Gene expression of both basal and catecholamine-stimulated lipolytic enzymes, adipose triglyceride lipase and hormone-sensitive lipase was inhibited in HC mice adipose tissue. The HC mice also had elevated fasting glucose (7.0 vs. 4.5 mmol/L, P<.001) and a greater area under the curve (P<.001) in intraperitoneal glucose tolerance tests, with enhanced expression of the negative regulator of insulin signaling, protein tyrosine phosphatase-1B, in liver and adipose tissue. Overall, high cystine intake promotes adiposity and an adverse metabolic phenotype in mice, indicating that the positive association of plasma tCys with obesity in humans may be causal.
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