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Moore MP, Shryack G, Alessi I, Wieschhaus N, Meers GM, Johnson SA, Wheeler AA, Ibdah JA, Parks EJ, Rector RS. Relationship between serum β-hydroxybutyrate and hepatic fatty acid oxidation in individuals with obesity and NAFLD. Am J Physiol Endocrinol Metab 2024; 326:E493-E502. [PMID: 38381399 PMCID: PMC11194052 DOI: 10.1152/ajpendo.00336.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 02/22/2024]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is characterized by excess lipid accumulation that can progress to inflammation (nonalcoholic steatohepatitis, NASH), and fibrosis. Serum β-hydroxybutyrate (β-HB), a product of the ketogenic pathway, is commonly used as a surrogate marker for hepatic fatty acid oxidation (FAO). However, it remains uncertain whether this relationship holds true in the context of NAFLD in humans. We compared fasting serum β-HB levels with direct measurement of liver mitochondrial palmitate oxidation in humans stratified based on NAFLD severity (n = 142). Patients were stratified based on NAFLD activity score (NAS): NAS = 0 (no disease), NAS = 1-2 (mild), NAS = 3-4 (moderate), and NAS ≥ 5 (advanced). Moderate and advanced NAFLD is associated with reductions in liver 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), serum β-HB, but not 3-hydroxy-3-methylglutaryl-CoA lyase (HMGCL) mRNA, relative to no disease. Worsening liver mitochondrial complete palmitate oxidation corresponded with lower HMGCS2 mRNA but not total (complete + incomplete) palmitate oxidation. Interestingly, we found that liver HMGCS2 mRNA and serum β-HB correlated with liver mitochondrial β-hydroxyacyl-CoA dehydrogenase (β-HAD) activity and CPT1A mRNA. Also, lower mitochondrial mass and markers of mitochondrial turnover positively correlated with lower HMGCS2 in the liver. These data suggest that liver ketogenesis and FAO occur at comparable rates in individuals with NAFLD. Our findings support the utility of serum β-HB to serve as a marker of liver injury and hepatic FAO in the context of NAFLD.NEW & NOTEWORTHY Serum β-hydroxybutyrate (β-HB) is frequently utilized as a surrogate marker for hepatic fatty acid oxidation; however, few studies have investigated this relationship during states of liver disease. We found that the progression of nonalcoholic fatty liver disease (NAFLD) is associated with reductions in circulating β-HB and liver 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2). As well, decreased rates of hepatic fatty acid oxidation correlated with liver HMGCS2 mRNA and serum β-HB. Our work supports serum β-HB as a potential marker for hepatic fatty acid oxidation and liver injury during NAFLD.
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Affiliation(s)
- Mary P Moore
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
| | - Grace Shryack
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
- NextGen Precision Health, Columbia, Missouri, United States
| | - Isabella Alessi
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
- NextGen Precision Health, Columbia, Missouri, United States
| | - Nicole Wieschhaus
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
- NextGen Precision Health, Columbia, Missouri, United States
| | - Grace M Meers
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
- NextGen Precision Health, Columbia, Missouri, United States
| | - Sarah A Johnson
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Andrew A Wheeler
- Department of Surgery, University of Missouri, Columbia, Missouri, United States
| | - Jamal A Ibdah
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Elizabeth J Parks
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
- NextGen Precision Health, Columbia, Missouri, United States
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, Missouri, United States
| | - R Scott Rector
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
- NextGen Precision Health, Columbia, Missouri, United States
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, Missouri, United States
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Zhao T, Zhao Y, Chen H, Sun W, Guan Y. A GC-MS-based untargeted metabolomics approach for comprehensive metabolic profiling of mycophenolate mofetil-induced toxicity in mice. Front Mol Biosci 2024; 11:1332090. [PMID: 38516185 PMCID: PMC10955473 DOI: 10.3389/fmolb.2024.1332090] [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: 11/02/2023] [Accepted: 02/08/2024] [Indexed: 03/23/2024] Open
Abstract
Background: Mycophenolate mofetil (MMF), the morpholinoethyl ester of mycophenolic acid, is widely used for maintenance immunosuppression in transplantation. The gastrointestinal toxicity of MMF has been widely uncovered. However, the comprehensive metabolic analysis of MMF-induced toxicity is lacking. This study is aimed to ascertain the metabolic changes after MMF administration in mice. Methods: A total of 700 mg MMF was dissolved in 7 mL dimethyl sulfoxide (DMSO), and then 0.5 mL of mixture was diluted with 4.5 mL of saline (100 mg/kg). Mice in the treatment group (n = 9) were given MMF (0.1 mL/10 g) each day via intraperitoneal injection lasting for 2 weeks, while those in the control group (n = 9) received the same amount of blank solvent (DMSO: saline = 1:9). Gas chromatography-mass spectrometry was utilized to identify the metabolic profiling in serum samples and multiple organ tissues of mice. The potential metabolites were identified using orthogonal partial least squares discrimination analysis. Meanwhile, we used the MetaboAnalyst 5.0 (http://www.metaboanalyst.ca) and Kyoto Encyclopedia of Genes and Genomes database (http://www.kegg.jp) to depict the metabolic pathways. The percentages of lymphocytes in spleens were assessed by multiparameter flow cytometry analysis. Results: Compared to the control group, we observed that MMF treatment induced differential expression of metabolites in the intestine, hippocampus, lung, liver, kidney, heart, serum, and cortex tissues. Subsequently, we demonstrated that multiple amino acids metabolism and fatty acids biosynthesis were disrupted following MMF treatment. Additionally, MMF challenge dramatically increased CD4+ T cell percentages but had no significant influences on other types of lymphocytes. Conclusion: MMF can affect the metabolism in various organs and serum in mice. These data may provide preliminary judgement for MMF-induced toxicity and understand the metabolic mechanism of MMF more comprehensively.
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Affiliation(s)
- Tongfeng Zhao
- Department of Hematology, Jining No.1 People’s Hospital, Jining, China
| | - Yaxin Zhao
- Department of Pharmacy, Jining No.1 People’s Hospital, Jining, China
| | - Haotian Chen
- Department of Hematology, Jining No.1 People’s Hospital, Jining, China
| | - Wenxue Sun
- Translational Pharmaceutical Laboratory, Jining No.1 People’s Hospital, Jining, China
- Postdoctoral of Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Yun Guan
- Department of Hematology, Jining No.1 People’s Hospital, Jining, China
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McBride MJ, Hunter CJ, Zhang Z, TeSlaa T, Xu X, Ducker GS, Rabinowitz JD. Glycine homeostasis requires reverse SHMT flux. Cell Metab 2024; 36:103-115.e4. [PMID: 38171330 DOI: 10.1016/j.cmet.2023.12.001] [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: 01/19/2023] [Revised: 10/09/2023] [Accepted: 12/04/2023] [Indexed: 01/05/2024]
Abstract
The folate-dependent enzyme serine hydroxymethyltransferase (SHMT) reversibly converts serine into glycine and a tetrahydrofolate-bound one-carbon unit. Such one-carbon unit production plays a critical role in development, the immune system, and cancer. Using rodent models, here we show that the whole-body SHMT flux acts to net consume rather than produce glycine. Pharmacological inhibition of whole-body SHMT1/2 and genetic knockout of liver SHMT2 elevated circulating glycine levels up to eight-fold. Stable-isotope tracing revealed that the liver converts glycine to serine, which is then converted by serine dehydratase into pyruvate and burned in the tricarboxylic acid cycle. In response to diets deficient in serine and glycine, de novo biosynthetic flux was unaltered, but SHMT2- and serine-dehydratase-mediated catabolic flux was lower. Thus, glucose-derived serine synthesis is largely insensitive to systemic demand. Instead, circulating serine and glycine homeostasis is maintained through variable consumption, with liver SHMT2 a major glycine-consuming enzyme.
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Affiliation(s)
- Matthew J McBride
- Department of Chemistry, Princeton University, Princeton, NJ, USA; Lewis-Sigler Institute of Integrative Genomics, Princeton University, Princeton, NJ, USA; Ludwig Institute for Cancer Research, Princeton University, Princeton, NJ, USA
| | - Craig J Hunter
- Department of Chemistry, Princeton University, Princeton, NJ, USA; Lewis-Sigler Institute of Integrative Genomics, Princeton University, Princeton, NJ, USA; Ludwig Institute for Cancer Research, Princeton University, Princeton, NJ, USA
| | - Zhaoyue Zhang
- Department of Chemistry, Princeton University, Princeton, NJ, USA; Lewis-Sigler Institute of Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Tara TeSlaa
- Department of Chemistry, Princeton University, Princeton, NJ, USA; Lewis-Sigler Institute of Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Xincheng Xu
- Department of Chemistry, Princeton University, Princeton, NJ, USA; Lewis-Sigler Institute of Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Gregory S Ducker
- Department of Chemistry, Princeton University, Princeton, NJ, USA; Lewis-Sigler Institute of Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Joshua D Rabinowitz
- Department of Chemistry, Princeton University, Princeton, NJ, USA; Lewis-Sigler Institute of Integrative Genomics, Princeton University, Princeton, NJ, USA; Ludwig Institute for Cancer Research, Princeton University, Princeton, NJ, USA.
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Li HJ, Wang YS, Wang YN, Liu AR, Su XH, Ma ZA, Wang LX, Zhang ZY, Lv SQ, Miao J, Cui HT. Mechanical study of alisol B 23-acetate on methionine and choline deficient diet-induced nonalcoholic steatohepatitis based on untargeted metabolomics. Biomed Chromatogr 2024; 38:e5763. [PMID: 37858975 DOI: 10.1002/bmc.5763] [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: 08/12/2023] [Revised: 09/21/2023] [Accepted: 10/03/2023] [Indexed: 10/21/2023]
Abstract
Alisol B 23-acetate (AB23A) has been demonstrated to have beneficial effects on nonalcoholic steatohepatitis (NASH). However, the mechanisms of AB23A on NASH remain unclear. This study aimed to investigate the mechanisms underlying the metabolic regulatory effects of AB23A on NASH. We used AB23A to treat mice with NASH, which was induced by a methionine and choline deficient (MCD) diet. We initially investigated therapeutic effect and resistance to oxidation and inflammation of AB23A on NASH. Subsequently, we performed untargeted metabolomic analyses and relative validation assessments to evaluate the metabolic regulatory effects of AB23A. AB23A reduced lipid accumulation, ameliorated oxidative stress and decreased pro-inflammatory cytokines in the liver. Untargeted metabolomic analysis found that AB23A altered the metabolites of liver. A total of 55 differential metabolites and three common changed pathways were screened among the control, model and AB23A treatment groups. Further tests validated the effects of AB23A on modulating common changed pathway-involved factors. AB23A treatment can ameliorate NASH by inhibiting oxidative stress and inflammation. The mechanism of AB23A on NASH may be related to the regulation of alanine, aspartate and glutamate metabolism, d-glutamine and d-glutamate metabolism, and arginine biosynthesis pathways.
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Affiliation(s)
- Hua-Jun Li
- Cangzhou Hospital of Integrated Traditional Chinese Medicine and Western Medicine of Hebei Province Affiliated to Hebei University of Chinese Medicine, Cangzhou, China
| | - Yuan-Song Wang
- Cangzhou Hospital of Integrated Traditional Chinese Medicine and Western Medicine of Hebei Province Affiliated to Hebei University of Chinese Medicine, Cangzhou, China
| | - Ya-Nan Wang
- Cangzhou Hospital of Integrated Traditional Chinese Medicine and Western Medicine of Hebei Province Affiliated to Hebei University of Chinese Medicine, Cangzhou, China
| | - Ai-Ru Liu
- Cangzhou Hospital of Integrated Traditional Chinese Medicine and Western Medicine of Hebei Province Affiliated to Hebei University of Chinese Medicine, Cangzhou, China
| | - Xiu-Hai Su
- Cangzhou Hospital of Integrated Traditional Chinese Medicine and Western Medicine of Hebei Province Affiliated to Hebei University of Chinese Medicine, Cangzhou, China
| | - Zi-Ang Ma
- Graduate School of Hebei University of Chinese Medicine, Shijiazhuang, China
| | - Li-Xin Wang
- Cangzhou Hospital of Integrated Traditional Chinese Medicine and Western Medicine of Hebei Province Affiliated to Hebei University of Chinese Medicine, Cangzhou, China
| | - Zhong-Yong Zhang
- Cangzhou Hospital of Integrated Traditional Chinese Medicine and Western Medicine of Hebei Province Affiliated to Hebei University of Chinese Medicine, Cangzhou, China
| | - Shu-Quan Lv
- Cangzhou Hospital of Integrated Traditional Chinese Medicine and Western Medicine of Hebei Province Affiliated to Hebei University of Chinese Medicine, Cangzhou, China
| | - Jing Miao
- Tianjin Second People's Hospital, Tianjin, China
| | - Huan-Tian Cui
- Yunnan University of Traditional Chinese Medicine, Kunming, China
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Syed-Abdul MM. Lipid Metabolism in Metabolic-Associated Steatotic Liver Disease (MASLD). Metabolites 2023; 14:12. [PMID: 38248815 PMCID: PMC10818604 DOI: 10.3390/metabo14010012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 01/23/2024] Open
Abstract
Metabolic-associated steatotic liver disease (MASLD) is a cluster of pathological conditions primarily developed due to the accumulation of ectopic fat in the hepatocytes. During the severe form of the disease, i.e., metabolic-associated steatohepatitis (MASH), accumulated lipids promote lipotoxicity, resulting in cellular inflammation, oxidative stress, and hepatocellular ballooning. If left untreated, the advanced form of the disease progresses to fibrosis of the tissue, resulting in irreversible hepatic cirrhosis or the development of hepatocellular carcinoma. Although numerous mechanisms have been identified as significant contributors to the development and advancement of MASLD, altered lipid metabolism continues to stand out as a major factor contributing to the disease. This paper briefly discusses the dysregulation in lipid metabolism during various stages of MASLD.
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Affiliation(s)
- Majid Mufaqam Syed-Abdul
- Toronto General Hospital Research Institute, University Health Network, University of Toronto, Toronto, ON M5G 1L7, Canada
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Ni Y, Wang W, Liu Y, Jiang Y. Causal associations between liver traits and Colorectal cancer: a Mendelian randomization study. BMC Med Genomics 2023; 16:316. [PMID: 38057864 PMCID: PMC10699049 DOI: 10.1186/s12920-023-01755-w] [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: 06/22/2023] [Accepted: 11/27/2023] [Indexed: 12/08/2023] Open
Abstract
OBJECTIVE This study aimed to investigate the causal associations between several liver traits (liver iron content, percent liver fat, alanine transaminase levels, and liver volume) and colorectal cancer (CRC) risk using a Mendelian randomization (MR) approach to improve our understanding of the disease and its management. METHODS Genetic variants were used as instrumental variables, extracted from genome-wide association studies (GWAS) datasets of liver traits and CRC. The Two-Sample MR package in R was used to conduct inverse variance weighted (IVW), MR Egger, Maximum likelihood, Weighted median, and Inverse variance weighted (multiplicative random effects) MR approaches to generate overall estimates of the effect. MR analysis was conducted with Benjamini-Hochberg method-corrected P values to account for multiple testing (P < 0.013). MR-PRESSO was used to identify and remove outlier genetic variants in Mendelian randomization (MR) analysis. The MR Steiger test was used to assess the validity of the assumption that exposure causes outcomes. Leave-one-out validation, pleiotropy, and heterogeneity testing were also conducted to ensure the reliability of the results. Multivariable MR was utilized for validation of our findings using the IVW method while also adjusting for potential confounding or pleiotropy bias. RESULTS The MR analysis suggested a causal effect between liver volume and a reduced risk of CRC (OR 0.60; 95% CI, 0.44-0.82; P = 0.0010) but did not provide evidence for causal effects of liver iron content, percent liver fat, or liver alanine transaminase levels. The MR-PRESSO method did not identify any outliers, and the MR Steiger test confirmed that the causal direction of the analysis results was correct in the Mendelian randomization analysis. MR results were consistent with heterogeneity and pleiotropy analyses, and leave-one-out analysis demonstrated the overall values obtained were consistent with estimates obtained when all available SNPs were included in the analysis. Multivariable MR was utilized for validation of our findings using the IVW method while also adjusting for potential confounding or pleiotropy bias. CONCLUSION The study provides tentative evidence for a causal role of liver volume in CRC, while genetically predicted levels of liver iron content, percent liver fat, and liver alanine transaminase levels were not associated with CRC risk. The findings may inform the development of targeted therapeutic interventions for colorectal liver metastasis (CRLM) patients, and the study highlights the importance of MR as a powerful epidemiological tool for investigating causal associations between exposures and outcomes.
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Affiliation(s)
- Ying Ni
- Beijing Normal University, 100875, Beijing, China
| | - Wenkai Wang
- Department of Oncology, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, 200021, Shanghai, China
| | - Yongming Liu
- Shi's Center of Orthopedics and Traumatology, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, 200021, Shanghai, China
- Institute of Traumatology & Orthopedics, Shanghai Academy of Traditional Chinese Medicine, 200021, Shanghai, China
| | - Yun Jiang
- Beijing Normal University, 100875, Beijing, China.
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Abstract
Amino acid dysregulation has emerged as an important driver of disease progression in various contexts. l-Serine lies at a central node of metabolism, linking carbohydrate metabolism, transamination, glycine, and folate-mediated one-carbon metabolism to protein synthesis and various downstream bioenergetic and biosynthetic pathways. l-Serine is produced locally in the brain but is sourced predominantly from glycine and one-carbon metabolism in peripheral tissues via liver and kidney metabolism. Compromised regulation or activity of l-serine synthesis and disposal occurs in the context of genetic diseases as well as chronic disease states, leading to low circulating l-serine levels and pathogenesis in the nervous system, retina, heart, and aging muscle. Dietary interventions in preclinical models modulate sensory neuropathy, retinopathy, tumor growth, and muscle regeneration. A serine tolerance test may provide a quantitative readout of l-serine homeostasis that identifies patients who may be susceptible to neuropathy or responsive to therapy.
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Affiliation(s)
- Michal K Handzlik
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA; ,
| | - Christian M Metallo
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA; ,
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8
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Inci MK, Park SH, Helsley RN, Attia SL, Softic S. Fructose impairs fat oxidation: Implications for the mechanism of western diet-induced NAFLD. J Nutr Biochem 2023; 114:109224. [PMID: 36403701 PMCID: PMC11042502 DOI: 10.1016/j.jnutbio.2022.109224] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 09/29/2022] [Accepted: 11/14/2022] [Indexed: 11/19/2022]
Abstract
Increased fructose intake from sugar-sweetened beverages and highly processed sweets is a well-recognized risk factor for the development of obesity and its complications. Fructose strongly supports lipogenesis on a normal chow diet by providing both, a substrate for lipid synthesis and activation of lipogenic transcription factors. However, the negative health consequences of dietary sugar are best observed with the concomitant intake of a HFD. Indeed, the most commonly used obesogenic research diets, such as "Western diet", contain both fructose and a high amount of fat. In spite of its common use, how the combined intake of fructose and fat synergistically supports development of metabolic complications is not fully elucidated. Here we present the preponderance of evidence that fructose consumption decreases oxidation of dietary fat in human and animal studies. We provide a detailed review of the mitochondrial β-oxidation pathway. Fructose affects hepatic activation of fatty acyl-CoAs, decreases acylcarnitine production and impairs the carnitine shuttle. Mechanistically, fructose suppresses transcriptional activity of PPARα and its target CPT1α, the rate limiting enzyme of acylcarnitine production. These effects of fructose may be, in part, mediated by protein acetylation. Acetylation of PGC1α, a co-activator of PPARα and acetylation of CPT1α, in part, account for fructose-impaired acylcarnitine production. Interestingly, metabolic effects of fructose in the liver can be largely overcome by carnitine supplementation. In summary, fructose decreases oxidation of dietary fat in the liver, in part, by impairing acylcarnitine production, offering one explanation for the synergistic effects of these nutrients on the development of metabolic complications, such as NAFLD.
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Affiliation(s)
| | - Se-Hyung Park
- Department of Pediatrics, University of Kentucky College of Medicine, Lexington, KY, USA; Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA
| | - Robert N Helsley
- Department of Pediatrics, University of Kentucky College of Medicine, Lexington, KY, USA; Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA; Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, USA
| | - Suzanna L Attia
- Department of Pediatrics, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Samir Softic
- Department of Pediatrics, University of Kentucky College of Medicine, Lexington, KY, USA; Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA; Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, MA, USA.
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McBride MJ, Hunter CJ, Rabinowitz JD. Glycine homeostasis requires reverse SHMT flux. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.11.523668. [PMID: 36711816 PMCID: PMC9882094 DOI: 10.1101/2023.01.11.523668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The folate-dependent enzyme serine hydroxymethyltransferase (SHMT) reversibly converts serine into glycine and a tetrahydrofolate-bound one-carbon unit. Such one-carbon unit production plays a critical role in development, the immune system, and cancer. Here we show that the whole-body SHMT flux acts to net consume rather than produce glycine. Pharmacological inhibition of whole-body SHMT1/2 and genetic knockout of liver SHMT2 elevated circulating glycine levels up to eight-fold. Stable isotope tracing revealed that the liver converts glycine to serine, which is then converted by serine dehydratase into pyruvate and burned in the tricarboxylic acid cycle. In response to diets deficient in serine and glycine, de novo biosynthetic flux was unaltered but SHMT2- and serine dehydratase-mediated catabolic flux was lower. Thus, glucose-derived serine synthesis does not respond to systemic demand. Instead, circulating serine and glycine homeostasis is maintained through variable consumption, with liver SHMT2 as a major glycine-consuming enzyme.
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10
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Lin C, Sun Z, Mei Z, Zeng H, Zhao M, Hu J, Xia M, Huang T, Wang C, Gao X, Zheng Y. The causal associations of circulating amino acids with blood pressure: a Mendelian randomization study. BMC Med 2022; 20:414. [PMID: 36307799 PMCID: PMC9615211 DOI: 10.1186/s12916-022-02612-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 10/17/2022] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Circulating levels of amino acids were associated with blood pressure (BP) in observational studies. However, the causation of such associations has been hypothesized but is difficult to prove in human studies. Here, we aimed to use two-sample Mendelian randomization analyses to evaluate the potential causal associations of circulating levels of amino acids with BP and risk of hypertension. METHODS We generated genetic instruments for circulating levels of nine amino acids by conducting meta-analyses of genome-wide association study (GWAS) in UK Biobank participants with metabolomic data (n = 98,317) and another published metabolomics GWAS (n = 24,925). Data on the associations of the genetic variants with BP and hypertension were obtained in the UK Biobank participants without metabolomic data (n = 286,390). The causal effects were estimated using inverse-variance weighted method. RESULTS Significant evidence consistently supported the causal effects of increased branched-chain amino acids (BCAAs, i.e., leucine, isoleucine, and valine) levels on higher BP and risk of hypertension (all P < 0.006 after Bonferroni correction except for Pleucine-on-diastolicBP = 0.008). For example, per standard deviation higher of genetically predicted isoleucine levels were associated with 2.71 ± 0.78 mmHg higher systolic BP and 1.24 ± 0.34 mmHg higher diastolic BP, as well as with 7% higher risk of hypertension (odds ratio: 1.07, [95% CI: 1.04-1.10]). In addition, per standard deviation higher of genetically predicted glycine level was associated with lower systolic BP (- 0.70 ± 0.17 mmHg, P = 4.04 × 10-5) and a lower risk of hypertension (0.99 [0.98-0.99], P = 6.46 × 10-5). In the reverse direction, genetically predicted higher systolic BP was associated with lower circulating levels of glycine (- 0.025±0.008, P = 0.001). CONCLUSIONS This study provides evidence for causal impacts of genetically predicted circulating BCAAs and glycine levels on BP. Meanwhile, genetically predicted higher BP was associated with lower glycine levels. Further investigations are warranted to clarify the underlying mechanisms.
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Affiliation(s)
- Chenhao Lin
- State Key Laboratory of Genetic Engineering, Human Phenome Institute and School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200433, China.,Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China
| | - Zhonghan Sun
- State Key Laboratory of Genetic Engineering, Human Phenome Institute and School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200433, China
| | - Zhendong Mei
- State Key Laboratory of Genetic Engineering, Human Phenome Institute and School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200433, China
| | - Hailuan Zeng
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan Institute for Metabolic Diseases, and Human Phenome Institute, Fudan University, Shanghai, China
| | - Manying Zhao
- State Key Laboratory of Genetic Engineering, Human Phenome Institute and School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200433, China
| | - Jianying Hu
- State Key Laboratory of Genetic Engineering, Human Phenome Institute and School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200433, China
| | - Mingfeng Xia
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan Institute for Metabolic Diseases, and Human Phenome Institute, Fudan University, Shanghai, China
| | - Tao Huang
- Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, China
| | - Chaolong Wang
- Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xin Gao
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan Institute for Metabolic Diseases, and Human Phenome Institute, Fudan University, Shanghai, China
| | - Yan Zheng
- State Key Laboratory of Genetic Engineering, Human Phenome Institute and School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200433, China. .,Ministry of Education Key Laboratory of Public Health Safety, School of Public Health, Fudan University, Shanghai, China.
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Hughey CC, Puchalska P, Crawford PA. Integrating the contributions of mitochondrial oxidative metabolism to lipotoxicity and inflammation in NAFLD pathogenesis. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159209. [DOI: 10.1016/j.bbalip.2022.159209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 06/25/2022] [Accepted: 07/27/2022] [Indexed: 11/28/2022]
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12
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Karkucinska-Wieckowska A, Simoes ICM, Kalinowski P, Lebiedzinska-Arciszewska M, Zieniewicz K, Milkiewicz P, Górska-Ponikowska M, Pinton P, Malik AN, Krawczyk M, Oliveira PJ, Wieckowski MR. Mitochondria, oxidative stress and nonalcoholic fatty liver disease: A complex relationship. Eur J Clin Invest 2022; 52:e13622. [PMID: 34050922 DOI: 10.1111/eci.13622] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 05/19/2021] [Accepted: 05/22/2021] [Indexed: 02/06/2023]
Abstract
According to the 'multiple-hit' hypothesis, several factors can act simultaneously in nonalcoholic fatty liver disease (NAFLD) progression. Increased nitro-oxidative (nitroso-oxidative) stress may be considered one of the main contributors involved in the development and risk of NAFLD progression to nonalcoholic steatohepatitis (NASH) characterized by inflammation and fibrosis. Moreover, it has been repeatedly postulated that mitochondrial abnormalities are closely related to the development and progression of liver steatosis and NAFLD pathogenesis. However, it is difficult to determine with certainty whether mitochondrial dysfunction or oxidative stress are primary events or a simple consequence of NAFLD development. On the one hand, increasing lipid accumulation in hepatocytes could cause a wide range of effects from mild to severe mitochondrial damage with a negative impact on cell fate. This can start the cascade of events, including an increase of cellular reactive nitrogen species (RNS) and reactive oxygen species (ROS) production that promotes disease progression from simple steatosis to more severe NAFLD stages. On the other hand, progressing mitochondrial bioenergetic catastrophe and oxidative stress manifestation could be considered accompanying events in the vast spectrum of abnormalities observed during the transition from NAFL to NASH and cirrhosis. This review updates our current understanding of NAFLD pathogenesis and clarifies whether mitochondrial dysfunction and ROS/RNS are culprits or bystanders of NAFLD progression.
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Affiliation(s)
| | - Ines C M Simoes
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Piotr Kalinowski
- Department of General, Transplant and Liver Surgery, Medical University of Warsaw, Warsaw, Poland
| | - Magdalena Lebiedzinska-Arciszewska
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Krzysztof Zieniewicz
- Department of General, Transplant and Liver Surgery, Medical University of Warsaw, Warsaw, Poland
| | - Piotr Milkiewicz
- Liver and Internal Medicine Unit, Department of General, Transplant and Liver Surgery, Medical University of Warsaw, Warsaw, Poland.,Translational Medicine Group, Pomeranian Medical University, Szczecin, Poland
| | | | - Paolo Pinton
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies, University of Ferrara, Ferrara, Italy
| | - Afshan N Malik
- Department of Diabetes, School of Life Course, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Marcin Krawczyk
- Laboratory of Metabolic Liver Diseases, Department of General, Transplant and Liver Surgery, Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland.,Department of Medicine II, Saarland University Medical Center, Saarland University, Homburg, Germany
| | - Paulo J Oliveira
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, CIBB - Centre for Innovative Biomedicine and Biotechnology, Coimbra, Portugal
| | - Mariusz R Wieckowski
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
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13
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Masoodi M, Gastaldelli A, Hyötyläinen T, Arretxe E, Alonso C, Gaggini M, Brosnan J, Anstee QM, Millet O, Ortiz P, Mato JM, Dufour JF, Orešič M. Metabolomics and lipidomics in NAFLD: biomarkers and non-invasive diagnostic tests. Nat Rev Gastroenterol Hepatol 2021; 18:835-856. [PMID: 34508238 DOI: 10.1038/s41575-021-00502-9] [Citation(s) in RCA: 194] [Impact Index Per Article: 64.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/15/2021] [Indexed: 02/07/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases worldwide and is often associated with aspects of metabolic syndrome. Despite its prevalence and the importance of early diagnosis, there is a lack of robustly validated biomarkers for diagnosis, prognosis and monitoring of disease progression in response to a given treatment. In this Review, we provide an overview of the contribution of metabolomics and lipidomics in clinical studies to identify biomarkers associated with NAFLD and nonalcoholic steatohepatitis (NASH). In addition, we highlight the key metabolic pathways in NAFLD and NASH that have been identified by metabolomics and lipidomics approaches and could potentially be used as biomarkers for non-invasive diagnostic tests. Overall, the studies demonstrated alterations in amino acid metabolism and several aspects of lipid metabolism including circulating fatty acids, triglycerides, phospholipids and bile acids. Although we report several studies that identified potential biomarkers, few have been validated.
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Affiliation(s)
- Mojgan Masoodi
- Institute of Clinical Chemistry, Bern University Hospital, Bern, Switzerland.
| | | | - Tuulia Hyötyläinen
- School of Natural Sciences and Technology, Örebro University, Örebro, Sweden
| | - Enara Arretxe
- OWL Metabolomics, Bizkaia Technology Park, Derio, Spain
| | | | | | | | - Quentin M Anstee
- Clinical & Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Oscar Millet
- Precision Medicine & Metabolism, CIC bioGUNE, CIBERehd, BRTA, Bizkaia Technology Park, Derio, Spain
| | - Pablo Ortiz
- OWL Metabolomics, Bizkaia Technology Park, Derio, Spain
| | - Jose M Mato
- Precision Medicine & Metabolism, CIC bioGUNE, CIBERehd, BRTA, Bizkaia Technology Park, Derio, Spain
| | - Jean-Francois Dufour
- University Clinic of Visceral Surgery and Medicine, Inselspital Bern, Bern, Switzerland.,Hepatology, Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Matej Orešič
- School of Medical Sciences, Örebro University, Örebro, Sweden. .,Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland.
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14
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Maternal DHA Supplementation during Pregnancy and Lactation in the Rat Protects the Offspring against High-Calorie Diet-Induced Hepatic Steatosis. Nutrients 2021; 13:nu13093075. [PMID: 34578953 PMCID: PMC8468499 DOI: 10.3390/nu13093075] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 08/29/2021] [Accepted: 08/30/2021] [Indexed: 12/16/2022] Open
Abstract
Maternal supplementation during pregnancy with docosahexaenoic acid (DHA) is internationally recommended to avoid postpartum maternal depression in the mother and improve cognitive and neurological outcomes in the offspring. This study was aimed at determining whether this nutritional intervention, in the rat, protects the offspring against the development of obesity and its associated metabolic disorders. Pregnant Wistar rats received an extract of fish oil enriched in DHA or saline (SAL) as placebo by mouth from the beginning of gestation to the end of lactation. At weaning, pups were fed standard chow or a free-choice, high-fat, high-sugar (fc-HFHS) diet. Compared to animals fed standard chow, rats exposed to the fc-HFHS diet exhibited increased body weight, liver weight, body fat and leptin in serum independently of saline or DHA maternal supplementation. Nevertheless, maternal DHA supplementation prevented both the glucose intolerance and the rise in serum insulin resulting from consumption of the fc-HFHS diet. In addition, animals from the DHA-fc-HFHS diet group showed decreased hepatic triglyceride accumulation compared to SAL-fc-HFHS rats. The beneficial effects on glucose homeostasis declined with age in male rats. Yet, the preventive action against hepatic steatosis was still present in 6-month-old animals of both sexes and was associated with decreased hepatic expression of lipogenic genes. The results of the present work show that maternal DHA supplementation during pregnancy programs a healthy phenotype into the offspring that was protective against the deleterious effects of an obesogenic diet.
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15
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von Loeffelholz C, Coldewey SM, Birkenfeld AL. A Narrative Review on the Role of AMPK on De Novo Lipogenesis in Non-Alcoholic Fatty Liver Disease: Evidence from Human Studies. Cells 2021; 10:cells10071822. [PMID: 34359991 PMCID: PMC8306246 DOI: 10.3390/cells10071822] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 07/01/2021] [Accepted: 07/15/2021] [Indexed: 02/06/2023] Open
Abstract
5′AMP-activated protein kinase (AMPK) is known as metabolic sensor in mammalian cells that becomes activated by an increasing adenosine monophosphate (AMP)/adenosine triphosphate (ATP) ratio. The heterotrimeric AMPK protein comprises three subunits, each of which has multiple phosphorylation sites, playing an important role in the regulation of essential molecular pathways. By phosphorylation of downstream proteins and modulation of gene transcription AMPK functions as a master switch of energy homeostasis in tissues with high metabolic turnover, such as the liver, skeletal muscle, and adipose tissue. Regulation of AMPK under conditions of chronic caloric oversupply emerged as substantial research target to get deeper insight into the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Evidence supporting the role of AMPK in NAFLD is mainly derived from preclinical cell culture and animal studies. Dysbalanced de novo lipogenesis has been identified as one of the key processes in NAFLD pathogenesis. Thus, the scope of this review is to provide an integrative overview of evidence, in particular from clinical studies and human samples, on the role of AMPK in the regulation of primarily de novo lipogenesis in human NAFLD.
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Affiliation(s)
- Christian von Loeffelholz
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, 07747 Jena, Germany;
- Correspondence: ; Tel.: +49-3641-9323-177; Fax: +49-3641-9323-102
| | - Sina M. Coldewey
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, 07747 Jena, Germany;
- Septomics Research Center, Jena University Hospital, 07747 Jena, Germany
- Center for Sepsis Control and Care, Jena University Hospital, 07747 Jena, Germany
| | - Andreas L. Birkenfeld
- Department of Diabetology Endocrinology and Nephrology, University Hospital Tübingen, Eberhard Karls University Tübingen, 72074 Tübingen, Germany;
- Department of Therapy of Diabetes, Institute of Diabetes Research and Metabolic Diseases in the Helmholtz Center Munich, Eberhard Karls University Tübingen, 72074 Tübingen, Germany
- Division of Diabetes and Nutritional Sciences, Rayne Institute, King’s College London, London SE5 9RJ, UK
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16
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Unraveling the role of Intralipid in suppressing off-target delivery and augmenting the therapeutic effects of anticancer nanomedicines. Acta Biomater 2021; 126:372-383. [PMID: 33774199 DOI: 10.1016/j.actbio.2021.03.044] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/12/2021] [Accepted: 03/17/2021] [Indexed: 01/08/2023]
Abstract
Intralipid, a clinically used lipid emulsion, was reportedly utilized as one strategy to suppress off-target delivery of anticancer nanomedicines; Intralipid also effectively improved drug delivery to tumors and produced better therapeutic effects. However, the mechanisms involved-the why and how-in Intralipid's facilitation of delivery of nanomedicines to tumors have not yet been reported in detail. In this study, we investigated Intralipid and discovered the beneficial effects of Intralipid pretreatment when using three anticancer nanomedicines, including the clinically approved drug doxorubicin (Doxil). Intralipid pretreatment induced a 40% reduction in liver uptake of a polymeric nanoprobe used in photodynamic therapy as well as a 1.5-fold-increased nanomedicine accumulation in tumors. This increased accumulation consequently led to significantly better therapeutic effects, and this finding was validated by using Doxil. As an interesting result, Intralipid pretreatment significantly prolonged the plasma half-life of nanomedicines in normal healthy mice but not in tumor-bearing mice, which suggests that tumors become an alternative route of nanomedicine delivery when liver delivery is suppressed. Also, we found markedly increased tumor blood flow, as measured by fluorescence angiography, and significantly lower blood viscosity after Intralipid pretreatment. All our results together indicate that Intralipid treatment not only suppressed off-target nanomedicine delivery by the reticuloendothelial system, but more important, it enhanced nanomedicine delivery to tumors by improving tumor blood flow, which is key to satisfactory drug delivery via the enhanced permeability and retention effect. Significantly better therapeutic outcomes were thus achieved by the strategy of combining utilization of nanomedicines and Intralipid pretreatment. STATEMENT OF SIGNIFICANCE: Off-target delivery to organs such as the liver and obstructed tumor blood flow as is often seen in advanced cancers are major barriers to the therapeutic efficacy of anticancer nanomedicines. Intralipid has been shown effective for suppressing nanomedicine accumulation in the liver, resulting in improved anticancer effects. Unraveling the mechanisms involved in this process will be greatly helpful for the clinical application of anticancer nanomedicines. We reported here that Intralipid could also significantly increase tumor delivery of nanomedicine, which is beneficial for improving tumor blood flow and lowering blood viscosity. To our knowledge, this is the first study to investigate the role of Intralipid in this regard. This knowledge provides a solid rationale for the use of Intralipid in combination with anticancer nanomedicines.
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17
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Immunity as Cornerstone of Non-Alcoholic Fatty Liver Disease: The Contribution of Oxidative Stress in the Disease Progression. Int J Mol Sci 2021; 22:ijms22010436. [PMID: 33406763 PMCID: PMC7795122 DOI: 10.3390/ijms22010436] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/18/2020] [Accepted: 12/30/2020] [Indexed: 12/12/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome and has become the major cause of chronic liver disease, especially in western countries. NAFLD encompasses a wide spectrum of hepatic histological alterations, from simple steatosis to steatohepatitis and cirrhosis with a potential development of hepatocellular carcinoma. Non-alcoholic steatohepatitis (NASH) is characterized by lobular inflammation and fibrosis. Several studies reported that insulin resistance, redox unbalance, inflammation, and lipid metabolism dysregulation are involved in NAFLD progression. However, the mechanisms beyond the evolution of simple steatosis to NASH are not clearly understood yet. Recent findings suggest that different oxidized products, such as lipids, cholesterol, aldehydes and other macromolecules could drive the inflammation onset. On the other hand, new evidence indicates innate and adaptive immunity activation as the driving force in establishing liver inflammation and fibrosis. In this review, we discuss how immunity, triggered by oxidative products and promoting in turn oxidative stress in a vicious cycle, fuels NAFLD progression. Furthermore, we explored the emerging importance of immune cell metabolism in determining inflammation, describing the potential application of trained immune discoveries in the NASH pathological context.
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18
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Simon J, Nuñez-García M, Fernández-Tussy P, Barbier-Torres L, Fernández-Ramos D, Gómez-Santos B, Buqué X, Lopitz-Otsoa F, Goikoetxea-Usandizaga N, Serrano-Macia M, Rodriguez-Agudo R, Bizkarguenaga M, Zubiete-Franco I, Gutiérrez-de Juan V, Cabrera D, Alonso C, Iruzubieta P, Romero-Gomez M, van Liempd S, Castro A, Nogueiras R, Varela-Rey M, Falcón-Pérez JM, Villa E, Crespo J, Lu SC, Mato JM, Aspichueta P, Delgado TC, Martínez-Chantar ML. Targeting Hepatic Glutaminase 1 Ameliorates Non-alcoholic Steatohepatitis by Restoring Very-Low-Density Lipoprotein Triglyceride Assembly. Cell Metab 2020; 31:605-622.e10. [PMID: 32084378 PMCID: PMC7259377 DOI: 10.1016/j.cmet.2020.01.013] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 02/05/2019] [Accepted: 01/28/2020] [Indexed: 12/21/2022]
Abstract
Non-alcoholic steatohepatitis (NASH) is characterized by the accumulation of hepatic fat in an inflammatory/fibrotic background. Herein, we show that the hepatic high-activity glutaminase 1 isoform (GLS1) is overexpressed in NASH. Importantly, GLS1 inhibition reduces lipid content in choline and/or methionine deprivation-induced steatotic mouse primary hepatocytes, in human hepatocyte cell lines, and in NASH mouse livers. We suggest that under these circumstances, defective glutamine fueling of anaplerotic mitochondrial metabolism and concomitant reduction of oxidative stress promotes a reprogramming of serine metabolism, wherein serine is shifted from the generation of the antioxidant glutathione and channeled to provide one-carbon units to regenerate the methionine cycle. The restored methionine cycle can induce phosphatidylcholine synthesis from the phosphatidylethanolamine N-methyltransferase-mediated and CDP-choline pathways as well as by base-exchange reactions between phospholipids, thereby restoring hepatic phosphatidylcholine content and very-low-density lipoprotein export. Overall, we provide evidence that hepatic GLS1 targeting is a valuable therapeutic approach in NASH.
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Affiliation(s)
- Jorge Simon
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Maitane Nuñez-García
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), 48940 Leioa, Bizkaia, Spain
| | - Pablo Fernández-Tussy
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Lucía Barbier-Torres
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - David Fernández-Ramos
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Beatriz Gómez-Santos
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), 48940 Leioa, Bizkaia, Spain
| | - Xabier Buqué
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), 48940 Leioa, Bizkaia, Spain; Biocruces Health Research Institute, 48903 Barakaldo, Bizkaia, Spain
| | - Fernando Lopitz-Otsoa
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Naroa Goikoetxea-Usandizaga
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Marina Serrano-Macia
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Rubén Rodriguez-Agudo
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Maider Bizkarguenaga
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Imanol Zubiete-Franco
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Virginia Gutiérrez-de Juan
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Diana Cabrera
- Metabolomics Platform, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | | | - Paula Iruzubieta
- Gastroenterology and Hepatology Department, Marqués de Valdecilla University Hospital, 39008 Santander, Spain; Clinical and Traslational Digestive Research Group, Instituto de Investigación Sanitaria Valdecilla (IDIVAL), 39011 Santander, Spain
| | - Manuel Romero-Gomez
- Unit for the Clinical Management of Digestive Diseases, Hospital Universitario Virgen del Rocío, CIBERehd, University of Seville, 41013 Seville, Spain
| | - Sebastiaan van Liempd
- Metabolomics Platform, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | | | - Ruben Nogueiras
- Department of Physiology, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de Compostela-Instituto de Investigación Sanitaria, CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Galician Agency of Innovation (GAIN), Xunta de Galicia, 15782 Santiago de Compostela, Spain
| | - Marta Varela-Rey
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Juan Manuel Falcón-Pérez
- Metabolomics Platform, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain; Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Bizkaia, Spain
| | - Erica Villa
- Department of Gastroenterology, Azienda Ospedaliero-Universitaria & University of Modena and Reggio Emilia, 41121 Modena, Italy
| | - Javier Crespo
- Gastroenterology and Hepatology Department, Marqués de Valdecilla University Hospital, 39008 Santander, Spain; Clinical and Traslational Digestive Research Group, Instituto de Investigación Sanitaria Valdecilla (IDIVAL), 39011 Santander, Spain
| | - Shelly C Lu
- Division of Digestive and Liver Diseases, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, United States
| | - Jose M Mato
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Patricia Aspichueta
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), 48940 Leioa, Bizkaia, Spain; Biocruces Health Research Institute, 48903 Barakaldo, Bizkaia, Spain
| | - Teresa C Delgado
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain.
| | - María Luz Martínez-Chantar
- Liver Disease Laboratory, Liver Metabolism Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain.
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19
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Simoes IC, Janikiewicz J, Bauer J, Karkucinska-Wieckowska A, Kalinowski P, Dobrzyń A, Wolski A, Pronicki M, Zieniewicz K, Dobrzyń P, Krawczyk M, Zischka H, Wieckowski MR, Potes Y. Fat and Sugar-A Dangerous Duet. A Comparative Review on Metabolic Remodeling in Rodent Models of Nonalcoholic Fatty Liver Disease. Nutrients 2019; 11:E2871. [PMID: 31771244 PMCID: PMC6950566 DOI: 10.3390/nu11122871] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/20/2019] [Accepted: 11/21/2019] [Indexed: 02/07/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a common disease in Western society and ranges from steatosis to steatohepatitis to end-stage liver disease such as cirrhosis and hepatocellular carcinoma. The molecular mechanisms that are involved in the progression of steatosis to more severe liver damage in patients are not fully understood. A deeper investigation of NAFLD pathogenesis is possible due to the many different animal models developed recently. In this review, we present a comparative overview of the most common dietary NAFLD rodent models with respect to their metabolic phenotype and morphological manifestation. Moreover, we describe similarities and controversies concerning the effect of NAFLD-inducing diets on mitochondria as well as mitochondria-derived oxidative stress in the progression of NAFLD.
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Affiliation(s)
- Ines C.M. Simoes
- Nencki Institute of Experimental Biology of Polish Academy of Sciences, 02-093 Warsaw, Poland (J.J.); (A.D.); (P.D.); (Y.P.)
| | - Justyna Janikiewicz
- Nencki Institute of Experimental Biology of Polish Academy of Sciences, 02-093 Warsaw, Poland (J.J.); (A.D.); (P.D.); (Y.P.)
| | - Judith Bauer
- Institute of Toxicology and Environmental Hygiene, Technical University Munich, School of Medicine, Biedersteiner Strasse 29, D-80802 Munich, Germany; (J.B.); (H.Z.)
| | | | - Piotr Kalinowski
- Department of General, Transplant and Liver Surgery, Medical University of Warsaw, 02-091 Warsaw, Poland; (P.K.); (K.Z.)
| | - Agnieszka Dobrzyń
- Nencki Institute of Experimental Biology of Polish Academy of Sciences, 02-093 Warsaw, Poland (J.J.); (A.D.); (P.D.); (Y.P.)
| | - Andrzej Wolski
- Department of Interventional Radiology and Neuroradiology, Medical University of Lublin, 20-090 Lublin, Poland;
| | - Maciej Pronicki
- Department of Pathology, The Children’s Memorial Health Institute, 04-730 Warsaw, Poland; (A.K.-W.); (M.P.)
| | - Krzysztof Zieniewicz
- Department of General, Transplant and Liver Surgery, Medical University of Warsaw, 02-091 Warsaw, Poland; (P.K.); (K.Z.)
| | - Paweł Dobrzyń
- Nencki Institute of Experimental Biology of Polish Academy of Sciences, 02-093 Warsaw, Poland (J.J.); (A.D.); (P.D.); (Y.P.)
| | - Marcin Krawczyk
- Laboratory of Metabolic Liver Diseases, Department of General, Transplant and Liver Surgery, Centre for Preclinical Research, Medical University of Warsaw, 02-091 Warsaw, Poland;
- Department of Medicine II, Saarland University Medical Center, 66421 Homburg, Germany
| | - Hans Zischka
- Institute of Toxicology and Environmental Hygiene, Technical University Munich, School of Medicine, Biedersteiner Strasse 29, D-80802 Munich, Germany; (J.B.); (H.Z.)
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, D-85764 Neuherberg, Germany
| | - Mariusz R. Wieckowski
- Nencki Institute of Experimental Biology of Polish Academy of Sciences, 02-093 Warsaw, Poland (J.J.); (A.D.); (P.D.); (Y.P.)
| | - Yaiza Potes
- Nencki Institute of Experimental Biology of Polish Academy of Sciences, 02-093 Warsaw, Poland (J.J.); (A.D.); (P.D.); (Y.P.)
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20
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McCullough A, Previs SF, Dasarathy J, Lee K, Osme A, Kim C, Ilchenko S, Lorkowski SW, Smith JD, Dasarathy S, Kasumov T. HDL flux is higher in patients with nonalcoholic fatty liver disease. Am J Physiol Endocrinol Metab 2019; 317:E852-E862. [PMID: 31503515 PMCID: PMC6879863 DOI: 10.1152/ajpendo.00193.2019] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 08/09/2019] [Accepted: 08/25/2019] [Indexed: 12/13/2022]
Abstract
Altered lipid metabolism and inflammation are involved in the pathogenesis of both nonalcoholic fatty liver disease (NAFLD) and cardiovascular disease (CVD). Even though high-density lipoprotein (HDL), a CVD protective marker, is decreased, whether HDL metabolism and function are perturbed in NAFLD are currently unknown. We examined the effect of NAFLD and disease severity on HDL metabolism and function in patients with biopsy-proven simple steatosis (SS), nonalcoholic steatohepatitis (NASH), and healthy controls. HDL turnover and HDL protein dynamics in SS (n = 7), NASH (n = 8), and healthy controls (n = 9) were studied in vivo. HDL maturation and remodeling, antioxidant, cholesterol efflux properties, and activities of lecithin-cholesterol ester acyltransferase and cholesterol ester transfer protein (CETP) were quantified using in vitro assays. All patients with NAFLD had increased turnover of both HDL cholesterol (HDLc; 0.16 ± 0.09 vs. 0.34 ± 0.18 days, P < 0.05) and apolipoprotein A1 (ApoAI) (0.26 ± 0.04 vs. 0.34 ± 0.06 days, P < 0.005) compared with healthy controls. The fractional catabolic rates of other HDL proteins, including ApoAII (and ApoAIV) were higher (P < 0.05) in patients with NAFLD who also had higher CETP activity, ApoAI/HDLc ratio (P < 0.05). NAFLD-induced alterations were associated with lower antioxidant (114.2 ± 46.6 vs. 220.5 ± 48.2 nmol·mL-1·min-1) but higher total efflux properties of HDL (23.4 ± 1.3% vs. 25.5 ± 2.3%) (both P < 0.05), which was more pronounced in individuals with NASH. However, no differences were observed in either HDL turnover, antioxidant, and cholesterol efflux functions of HDL or HDL proteins' turnover between subjects with SS and subjects with NASH. Thus, HDL metabolism and function are altered in NAFLD without any significant differences between SS and NASH.
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Affiliation(s)
| | | | | | - Kwangwon Lee
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio
| | - Abdullah Osme
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio
| | - Chunki Kim
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio
| | - Serguei Ilchenko
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio
| | - Shuhui W Lorkowski
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, Ohio
| | - Jonathan D Smith
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, Ohio
| | | | - Takhar Kasumov
- Department of Gastroenterology, Cleveland Clinic, Cleveland, Ohio
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio
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21
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Glycine Metabolism and Its Alterations in Obesity and Metabolic Diseases. Nutrients 2019; 11:nu11061356. [PMID: 31208147 PMCID: PMC6627940 DOI: 10.3390/nu11061356] [Citation(s) in RCA: 182] [Impact Index Per Article: 36.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 06/07/2019] [Accepted: 06/12/2019] [Indexed: 12/11/2022] Open
Abstract
Glycine is the proteinogenic amino-acid of lowest molecular weight, harboring a hydrogen atom as a side-chain. In addition to being a building-block for proteins, glycine is also required for multiple metabolic pathways, such as glutathione synthesis and regulation of one-carbon metabolism. Although generally viewed as a non-essential amino-acid, because it can be endogenously synthesized to a certain extent, glycine has also been suggested as a conditionally essential amino acid. In metabolic disorders associated with obesity, type 2 diabetes (T2DM), and non-alcoholic fatty liver disease (NAFLDs), lower circulating glycine levels have been consistently observed, and clinical studies suggest the existence of beneficial effects induced by glycine supplementation. The present review aims at synthesizing the recent advances in glycine metabolism, pinpointing its main metabolic pathways, identifying the causes leading to glycine deficiency-especially in obesity and associated metabolic disorders-and evaluating the potential benefits of increasing glycine availability to curb the progression of obesity and obesity-related metabolic disturbances. This study focuses on the importance of diet, gut microbiota, and liver metabolism in determining glycine availability in obesity and associated metabolic disorders.
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22
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Ipsen DH, Lykkesfeldt J, Tveden-Nyborg P. Molecular mechanisms of hepatic lipid accumulation in non-alcoholic fatty liver disease. Cell Mol Life Sci 2018; 75:3313-3327. [PMID: 29936596 PMCID: PMC6105174 DOI: 10.1007/s00018-018-2860-6] [Citation(s) in RCA: 772] [Impact Index Per Article: 128.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/18/2018] [Accepted: 06/20/2018] [Indexed: 12/17/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is currently the world's most common liver disease, estimated to affect up to one-fourth of the population. Hallmarked by hepatic steatosis, NAFLD is associated with a multitude of detrimental effects and increased mortality. This narrative review investigates the molecular mechanisms of hepatic steatosis in NAFLD, focusing on the four major pathways contributing to lipid homeostasis in the liver. Hepatic steatosis is a consequence of lipid acquisition exceeding lipid disposal, i.e., the uptake of fatty acids and de novo lipogenesis surpassing fatty acid oxidation and export. In NAFLD, hepatic uptake and de novo lipogenesis are increased, while a compensatory enhancement of fatty acid oxidation is insufficient in normalizing lipid levels and may even promote cellular damage and disease progression by inducing oxidative stress, especially with compromised mitochondrial function and increased oxidation in peroxisomes and cytochromes. While lipid export initially increases, it plateaus and may even decrease with disease progression, sustaining the accumulation of lipids. Fueled by lipo-apoptosis, hepatic steatosis leads to systemic metabolic disarray that adversely affects multiple organs, placing abnormal lipid metabolism associated with NAFLD in close relation to many of the current life-style-related diseases.
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Affiliation(s)
- David Højland Ipsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 9, 1870, Frederiksberg C, Denmark
| | - Jens Lykkesfeldt
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 9, 1870, Frederiksberg C, Denmark
| | - Pernille Tveden-Nyborg
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 9, 1870, Frederiksberg C, Denmark.
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23
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Lee K, Haddad A, Osme A, Kim C, Borzou A, Ilchenko S, Allende D, Dasarathy S, McCullough A, Sadygov RG, Kasumov T. Hepatic Mitochondrial Defects in a Nonalcoholic Fatty Liver Disease Mouse Model Are Associated with Increased Degradation of Oxidative Phosphorylation Subunits. Mol Cell Proteomics 2018; 17:2371-2386. [PMID: 30171159 DOI: 10.1074/mcp.ra118.000961] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Revised: 08/21/2018] [Indexed: 12/11/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is associated with hepatic mitochondrial dysfunction characterized by reduced ATP synthesis. We applied the 2H2O-metabolic labeling approach to test the hypothesis that the reduced stability of oxidative phosphorylation proteins contributes to mitochondrial dysfunction in a diet-induced mouse model of NAFLD. A high fat diet containing cholesterol (a so-called Western diet (WD)) led to hepatic oxidative stress, steatosis, inflammation and mild fibrosis, all markers of NAFLD, in low density cholesterol (LDL) receptor deficient (LDLR-/-) mice. In addition, compared with controls (LDLR-/- mice on normal diet), livers from NAFLD mice had reduced citrate synthase activity and ATP content, suggesting mitochondrial impairment. Proteome dynamics study revealed that mitochondrial defects are associated with reduced average half-lives of mitochondrial proteins in NAFLD mice (5.41 ± 0.46 versus 5.15 ± 0.49 day, p < 0.05). In particular, the WD reduced stability of oxidative phosphorylation subunits, including cytochrome b-c1 complex subunit 1 (5.9 ± 0.1 versus 3.4 ± 0.8 day), ATP synthase subunit α (6.3 ± 0.4 versus 5.5 ± 0.4 day) and ATP synthase F(0) complex subunit B1 of complex V (8.5 ± 0.6 versus 6.5 ± 0.2 day) (p < 0.05). These changes were associated with impaired complex III and F0F1-ATP synthase activities. Markers of mitophagy were increased, but proteasomal degradation activity were reduced in NAFLD mice liver, suggesting that ATP deficiency because of reduced stability of oxidative phosphorylation complex subunits contributed to inhibition of ubiquitin-proteasome and activation of mitophagy. In conclusion, the 2H2O-metabolic labeling approach shows that increased degradation of hepatic oxidative phosphorylation subunits contributed to mitochondrial impairment in NAFLD mice.
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Affiliation(s)
- Kwangwon Lee
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Andrew Haddad
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Abdullah Osme
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Chunki Kim
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Ahmad Borzou
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77555
| | - Sergei Ilchenko
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Daniela Allende
- Department of Pathology, Cleveland Clinic Foundation, Cleveland, Ohio 44195
| | | | - Arthur McCullough
- Department of Hepatology, Cleveland Clinic Foundation, Cleveland, Ohio 44195
| | - Rovshan G Sadygov
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77555
| | - Takhar Kasumov
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio 44272; Department of Hepatology, Cleveland Clinic Foundation, Cleveland, Ohio 44195.
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Beaulieu L, Vitseva O, Tanriverdi K, Kucukural A, Mick E, Hamburg N, Vita J, Freedman J. Platelet functional and transcriptional changes induced by intralipid infusion. Thromb Haemost 2017; 115:1147-56. [DOI: 10.1160/th15-09-0739] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 02/11/2016] [Indexed: 02/07/2023]
Abstract
SummaryMultiple studies have shown the effects of long-term exposure to high-fat or western diets on the vascular system. There is limited knowledge on the acute effects of high circulating fat levels, specifically on platelets, which have a role in many processes, including thrombosis and inflammation. This study investigated the effects of acute, high-fat exposure on platelet function and transcript profile. Twenty healthy participants were given an intravenous infusion of 20% Intralipid emulsion and heparin over 6 hours. Blood samples were taken prior to and the day after infusion to measure platelet function and transcript expression levels. Platelet aggregation was not significantly affected by Intralipid infusion, but, when mitochondria function was inhibited by carbonyl cyanide 3-chlorophenylhydrazone (CCCP) or oligomycin, platelet aggregation was higher in the post-infusion state compared to baseline. Through RNA sequencing, and verified by RT-qPCR, 902 miRNAs and 617 mRNAs were affected by Intralipid infusion. MicroRNAs increased include miR-4259 and miR-346, while miR-517b and miR-517c are both decreased. Pathway analysis identified two clusters significantly enriched, including cell motility. In conclusion, acute exposure to high fat affects mitochondrial-dependent platelet function, as well as the transcript profile.
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25
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von Loeffelholz C, Döcke S, Lock JF, Lieske S, Horn P, Kriebel J, Wahl S, Singmann P, de Las Heras Gala T, Grallert H, Raschzok N, Sauer IM, Heller R, Jahreis G, Claus RA, Bauer M, Stockmann M, Birkenfeld AL, Pfeiffer AFH. Increased lipogenesis in spite of upregulated hepatic 5'AMP-activated protein kinase in human non-alcoholic fatty liver. Hepatol Res 2017; 47:890-901. [PMID: 27689765 DOI: 10.1111/hepr.12825] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 09/10/2016] [Accepted: 09/28/2016] [Indexed: 12/31/2022]
Abstract
AIMS Molecular adaptations in human non-alcoholic fatty liver disease (NAFLD) are incompletely understood. This study investigated the main gene categories related to hepatic de novo lipogenesis and lipid oxidation capacity. METHODS Liver specimens of 48 subjects were histologically classified according to steatosis severity. In-depth analyses were undertaken using real-time polymerase chain reaction, immunoblotting, and immunohistochemistry. Lipid profiles were analyzed by gas chromatography/flame ionization detection, and effects of key fatty acids were studied in primary human hepatocytes. RESULTS Real-time polymerase chain reaction, immunoblotting, and immunohistochemistry indicated 5'AMP-activated protein kinase (AMPK) to be increased with steatosis score ≥ 2 (all P < 0.05), including various markers of de novo lipogenesis and lipid degradation (all P < 0.05). Regarding endoplasmic reticulum stress, X-Box binding protein-1 (XBP1) was upregulated in steatosis score ≥ 2 (P = 0.029) and correlated with plasma palmitate (r = 0.34; P = 0.035). Palmitate incubation of primary human hepatocytes increased XBP1 and downstream stearoyl CoA desaturase-1 mRNA expression (both P < 0.05). Moreover, plasma and liver tissue exposed a NAFLD-related lipid profile with reduced polyunsaturated/saturated fatty acid ratio, increased palmitate and palmitoleate, and elevated lipogenesis and desaturation indices with steatosis score ≥ 2 (all P < 0.05). CONCLUSION In humans with advanced fatty liver disease, hepatic AMPK protein is upregulated, potentially in a compensatory manner. Moreover, pathways of lipid synthesis and degradation are co-activated in subjects with advanced steatosis. Palmitate may drive lipogenesis by activating XBP1-mediated endoplasmic reticulum stress and represent a target for future dietary or pharmacological intervention.
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Affiliation(s)
- Christian von Loeffelholz
- Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany.,Department of Anaesthesiology and Intensive Care, Jena University Hospital, and Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Friedrich Schiller University, Jena, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Stephanie Döcke
- Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany
| | - Johan F Lock
- Department of General-, Visceral-, Vascular- and Paediatric Surgery, University Hospital of Wuerzburg, Wuerzburg, Germany
| | - Stefanie Lieske
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Paul Horn
- Department of Anaesthesiology and Intensive Care, Jena University Hospital, and Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Friedrich Schiller University, Jena, Germany
| | - Jennifer Kriebel
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany.,Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.,Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Simone Wahl
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany.,Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.,Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Paula Singmann
- Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.,Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Tonia de Las Heras Gala
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany.,Research Group of Diabetes Epidemiology, Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Harald Grallert
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany.,Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.,Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Nathaniel Raschzok
- Department of General, Visceral and Transplantation Surgery, Charité-Universitätsmedizin, Berlin, Germany
| | - Igor M Sauer
- Department of General, Visceral and Transplantation Surgery, Charité-Universitätsmedizin, Berlin, Germany
| | - Regine Heller
- Department of Anaesthesiology and Intensive Care, Jena University Hospital, and Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Friedrich Schiller University, Jena, Germany.,Institute for Molecular Cell Biology, Germany, Center for Molecular Biomedicine, Jena University Hospital, Jena, Germany
| | - Gerhard Jahreis
- Institute of Nutrition, Friedrich Schiller University, Jena, Germany
| | - Ralf A Claus
- Department of Anaesthesiology and Intensive Care, Jena University Hospital, and Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Friedrich Schiller University, Jena, Germany
| | - Michael Bauer
- Department of Anaesthesiology and Intensive Care, Jena University Hospital, and Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Friedrich Schiller University, Jena, Germany
| | - Martin Stockmann
- Department of General, Visceral and Transplantation Surgery, Charité-Universitätsmedizin, Berlin, Germany
| | - Andreas L Birkenfeld
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Andreas F H Pfeiffer
- Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany.,Department of Endocrinology, Diabetes, and Nutrition, Charité-Universitätsmedizin, Berlin, Germany
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McCullough A, Previs S, Kasumov T. Stable isotope-based flux studies in nonalcoholic fatty liver disease. Pharmacol Ther 2017; 181:22-33. [PMID: 28720429 DOI: 10.1016/j.pharmthera.2017.07.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and is associated with the worldwide epidemics of obesity, diabetes and cardiovascular diseases. NAFLD ranges from benign fat accumulation in the liver (steatosis) to non-alcoholic steatohepatitis (NASH), and cirrhosis which can progress to hepatocellular carcinoma and liver failure. Mass spectrometry and magnetic resonance spectroscopy-coupled stable isotope-based flux studies provide new insights into the understanding of NAFLD pathogenesis and the disease progression. This review focuses mainly on the utilization of mass spectrometry-based methods for the understanding of metabolic abnormalities in the different stages of NAFLD. For example, stable isotope-based flux studies demonstrated multi-organ insulin resistance, dysregulated glucose, lipids and lipoprotein metabolism in patients with NAFLD. We also review recent developments in the stable isotope-based technologies for the study of mitochondrial dysfunction, oxidative stress and fibrogenesis in NAFLD. We highlight the limitations of current methodologies, discuss the emerging areas of research in this field, and future directions for the applications of stable isotopes to study NAFLD and its complications.
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Affiliation(s)
- Arthur McCullough
- Department of Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, OH, USA
| | | | - Takhar Kasumov
- Department of Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, OH, USA; Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, OH, USA.
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Multifarious Beneficial Effect of Nonessential Amino Acid, Glycine: A Review. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:1716701. [PMID: 28337245 PMCID: PMC5350494 DOI: 10.1155/2017/1716701] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 02/07/2017] [Accepted: 02/07/2017] [Indexed: 02/06/2023]
Abstract
Glycine is most important and simple, nonessential amino acid in humans, animals, and many mammals. Generally, glycine is synthesized from choline, serine, hydroxyproline, and threonine through interorgan metabolism in which kidneys and liver are the primarily involved. Generally in common feeding conditions, glycine is not sufficiently synthesized in humans, animals, and birds. Glycine acts as precursor for several key metabolites of low molecular weight such as creatine, glutathione, haem, purines, and porphyrins. Glycine is very effective in improving the health and supports the growth and well-being of humans and animals. There are overwhelming reports supporting the role of supplementary glycine in prevention of many diseases and disorders including cancer. Dietary supplementation of proper dose of glycine is effectual in treating metabolic disorders in patients with cardiovascular diseases, several inflammatory diseases, obesity, cancers, and diabetes. Glycine also has the property to enhance the quality of sleep and neurological functions. In this review we will focus on the metabolism of glycine in humans and animals and the recent findings and advances about the beneficial effects and protection of glycine in different disease states.
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28
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Division of labour: how does folate metabolism partition between one-carbon metabolism and amino acid oxidation? Biochem J 2016; 472:135-46. [PMID: 26567272 DOI: 10.1042/bj20150837] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
One-carbon metabolism is usually represented as having three canonical functions: purine synthesis, thymidylate synthesis and methylation reactions. There is however a fourth major function: the metabolism of some amino acids (serine, glycine, tryptophan and histidine), as well as choline. These substrates can provide cells with more one-carbon groups than they need for these three canonical functions. Therefore, there must be mechanisms for the disposal of these one-carbon groups (when in excess) which maintain the complement of these groups required for the canonical functions. The key enzyme for these mechanisms is 10-formyl-THF (tetrahydrofolate) dehydrogenase (both mitochondrial and cytoplasmic isoforms) which oxidizes the formyl group to CO2 with the attendant reduction of NADP(+) to NADPH and release of THF. In addition to oxidizing the excess of these compounds, this process can reduce substantial quantities of NADP(+) to NADPH.
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Whole body creatine and protein kinetics in healthy men and women: effects of creatine and amino acid supplementation. Amino Acids 2015; 48:677-687. [PMID: 26480831 DOI: 10.1007/s00726-015-2111-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 10/01/2015] [Indexed: 01/27/2023]
Abstract
Creatine kinetics were measured in young healthy subjects, eight males and seven females, age 20-30 years, after an overnight fast on creatine-free diet. Whole body turnover of glycine and its appearance in creatine was quantified using [1-(13)C] glycine and the rate of protein turnover was quantified using L-ring [(2)H5] phenylalanine. The creatine pool size was estimated by the dilution of a bolus [C(2)H3] creatine. Studies were repeated following a five days supplement creatine 21 g.day(-1) and following supplement amino acids 14.3 g day(-1). Creatine caused a ten-fold increase in the plasma concentration of creatine and a 50 % decrease in the concentration of guanidinoacetic acid. Plasma amino acids profile showed a significant decrease in glycine, glutamine, and taurine and a significant increase in citrulline, valine, lysine, and cysteine. There was a significant decrease in the rate of appearance of glycine, suggesting a decrease in de-novo synthesis (p = 0.006). The fractional and absolute rate of synthesis of creatine was significantly decreased by supplemental creatine. Amino acid supplement had no impact on any of the parameters. This is the first detailed analysis of creatine kinetics and the effects of creatine supplement in healthy young men and women. These methods can be applied for the analysis of creatine kinetics in different physiological states.
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Pacana T, Cazanave S, Verdianelli A, Patel V, Min HK, Mirshahi F, Quinlivan E, Sanyal AJ. Dysregulated Hepatic Methionine Metabolism Drives Homocysteine Elevation in Diet-Induced Nonalcoholic Fatty Liver Disease. PLoS One 2015; 10:e0136822. [PMID: 26322888 PMCID: PMC4556375 DOI: 10.1371/journal.pone.0136822] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 08/10/2015] [Indexed: 12/30/2022] Open
Abstract
Methionine metabolism plays a central role in methylation reactions, production of glutathione and methylarginines, and modulating homocysteine levels. The mechanisms by which these are affected in NAFLD are not fully understood. The aim is to perform a metabolomic, molecular and epigenetic analyses of hepatic methionine metabolism in diet-induced NAFLD. Female 129S1/SvlmJ;C57Bl/6J mice were fed a chow (n = 6) or high-fat high-cholesterol (HFHC) diet (n = 8) for 52 weeks. Metabolomic study, enzymatic expression and DNA methylation analyses were performed. HFHC diet led to weight gain, marked steatosis and extensive fibrosis. In the methionine cycle, hepatic methionine was depleted (30%, p< 0.01) while s-adenosylmethionine (SAM)/methionine ratio (p< 0.05), s-adenosylhomocysteine (SAH) (35%, p< 0.01) and homocysteine (25%, p< 0.01) were increased significantly. SAH hydrolase protein levels decreased significantly (p <0.01). Serine, a substrate for both homocysteine remethylation and transsulfuration, was depleted (45%, p< 0.01). In the transsulfuration pathway, cystathionine and cysteine trended upward while glutathione decreased significantly (p< 0.05). In the transmethylation pathway, levels of glycine N-methyltransferase (GNMT), the most abundant methyltransferase in the liver, decreased. The phosphatidylcholine (PC)/ phosphatidylethanolamine (PE) ratio increased significantly (p< 0.01), indicative of increased phosphatidylethanolamine methyltransferase (PEMT) activity. The protein levels of protein arginine methytransferase 1 (PRMT1) increased significantly, but its products, monomethylarginine (MMA) and asymmetric dimethylarginine (ADMA), decreased significantly. Circulating ADMA increased and approached significance (p< 0.06). Protein expression of methionine adenosyltransferase 1A, cystathionine β-synthase, γ-glutamylcysteine synthetase, betaine-homocysteine methyltransferase, and methionine synthase remained unchanged. Although gene expression of the DNA methyltransferase Dnmt3a decreased, the global DNA methylation was unaltered. Among individual genes, only HMG-CoA reductase (Hmgcr) was hypermethylated, and no methylation changes were observed in fatty acid synthase (Fasn), nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 (Nfκb1), c-Jun, B-cell lymphoma 2 (Bcl-2) and Caspase 3. NAFLD was associated with hepatic methionine deficiency and homocysteine elevation, resulting mainly from impaired homocysteine remethylation, and aberrancy in methyltransferase reactions. Despite increased PRMT1 expression, hepatic ADMA was depleted while circulating ADMA was increased, suggesting increased export to circulation.
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Affiliation(s)
- Tommy Pacana
- Div. of Gastroenterology, Hepatology and Nutrition, Dept. of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, United States of America
- * E-mail: (AJS); (TP)
| | - Sophie Cazanave
- Div. of Gastroenterology, Hepatology and Nutrition, Dept. of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, United States of America
| | - Aurora Verdianelli
- Div. of Gastroenterology, Hepatology and Nutrition, Dept. of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, United States of America
| | - Vaishali Patel
- Div. of Gastroenterology, Hepatology and Nutrition, Dept. of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, United States of America
| | - Hae-Ki Min
- Div. of Gastroenterology, Hepatology and Nutrition, Dept. of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, United States of America
| | - Faridoddin Mirshahi
- Div. of Gastroenterology, Hepatology and Nutrition, Dept. of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, United States of America
| | - Eoin Quinlivan
- Biomedical Mass Spectrometry Laboratory, General Clinical Research Center, University of Florida, Gainesville, FL, United States of America
| | - Arun J. Sanyal
- Div. of Gastroenterology, Hepatology and Nutrition, Dept. of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, United States of America
- * E-mail: (AJS); (TP)
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Tsien C, Davuluri G, Singh D, Allawy A, Ten Have GAM, Thapaliya S, Schulze JM, Barnes D, McCullough AJ, Engelen MP, Deutz NE, Dasarathy S. Metabolic and molecular responses to leucine-enriched branched chain amino acid supplementation in the skeletal muscle of alcoholic cirrhosis. Hepatology 2015; 61:2018-29. [PMID: 25613922 PMCID: PMC4441611 DOI: 10.1002/hep.27717] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 12/22/2014] [Accepted: 01/20/2015] [Indexed: 12/12/2022]
Abstract
UNLABELLED Skeletal muscle loss (sarcopenia) is a major clinical complication in alcoholic cirrhosis with no effective therapy. Skeletal muscle autophagic proteolysis and myostatin expression (inhibitor of protein synthesis) are increased in cirrhosis and believed to contribute to anabolic resistance. A prospective study was performed to determine the mechanisms of sarcopenia in alcoholic cirrhosis and potential reversal by leucine. In six well-compensated, stable, alcoholic patients with cirrhosis and eight controls, serial vastus lateralis muscle biopsies were obtained before and 7 hours after a single oral branched chain amino acid mixture enriched with leucine (BCAA/LEU). Primed-constant infusion of l-[ring-(2) H5 ]-phenylalanine was used to quantify whole-body protein breakdown and muscle protein fractional synthesis rate using liquid chromatography/mass spectrometry. Muscle expression of myostatin, mammalian target of rapamycin (mTOR) targets, autophagy markers, protein ubiquitination, and the intracellular amino acid deficiency sensor general control of nutrition 2 were quantified by immunoblots and the leucine exchanger (SLC7A5) and glutamine transporter (SLC38A2), by real-time polymerase chain reaction. Following oral administration, plasma BCAA concentrations showed a similar increase in patients with cirrhosis and controls. Skeletal muscle fractional synthesis rate was 9.63 ± 0.36%/hour in controls and 9.05 ± 0.68%/hour in patients with cirrhosis (P = 0.54). Elevated whole-body protein breakdown in patients with cirrhosis was reduced with BCAA/LEU (P = 0.01). Fasting skeletal muscle molecular markers showed increased myostatin expression, impaired mTOR signaling, and increased autophagy in patients with cirrhosis compared to controls (P < 0.01). The BCAA/LEU supplement did not alter myostatin expression, but mTOR signaling, autophagy measures, and general control of nutrition 2 activation were consistently reversed in cirrhotic muscle (P < 0.01). Expression of SLC7A5 was higher in the basal state in patients with cirrhosis than controls (P < 0.05) but increased with BCAA/LEU only in controls (P < 0.001). CONCLUSIONS Impaired mTOR1 signaling and increased autophagy in skeletal muscle of patients with alcoholic cirrhosis is acutely reversed by BCAA/LEU.
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Affiliation(s)
- Cynthia Tsien
- Departments of Gastroenterology, Toronto General Hospital, Toronto, Canada
| | | | - Dharmvir Singh
- Departments of Gastroenterology, Hepatology, Cleveland Clinic, Cleveland Ohio
| | - Allawy Allawy
- Department of Pathobiology, Cleveland Clinic, Cleveland Ohio
| | | | - Samjhana Thapaliya
- Departments of Gastroenterology, Hepatology, Cleveland Clinic, Cleveland Ohio
| | - John M Schulze
- Molecular Structure Facility, University of California, Davis, California
| | - David Barnes
- Departments of Gastroenterology, Hepatology, Cleveland Clinic, Cleveland Ohio
| | | | | | | | - Srinivasan Dasarathy
- Department of Pathobiology, Cleveland Clinic, Cleveland Ohio,Departments of Gastroenterology, Hepatology, Cleveland Clinic, Cleveland Ohio
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Nonalcoholic Fatty liver disease: pathogenesis and therapeutics from a mitochondria-centric perspective. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:637027. [PMID: 25371775 PMCID: PMC4211163 DOI: 10.1155/2014/637027] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 07/31/2014] [Accepted: 07/31/2014] [Indexed: 12/12/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) describes a spectrum of disorders characterized by the accumulation of triglycerides within the liver. The global prevalence of NAFLD has been increasing as the obesity epidemic shows no sign of relenting. Mitochondria play a central role in hepatic lipid metabolism and also are affected by upstream signaling pathways involved in hepatic metabolism. This review will focus on the role of mitochondria in the pathophysiology of NAFLD and touch on some of the therapeutic approaches targeting mitochondria as well as metabolically important signaling pathways. Mitochondria are able to adapt to lipid accumulation in hepatocytes by increasing rates of beta-oxidation; however increased substrate delivery to the mitochondrial electron transport chain (ETC) leads to increased reactive oxygen species (ROS) production and eventually ETC dysfunction. Decreased ETC function combined with increased rates of fatty acid beta-oxidation leads to the accumulation of incomplete products of beta-oxidation, which combined with increased levels of ROS contribute to insulin resistance. Several related signaling pathways, nuclear receptors, and transcription factors also regulate hepatic lipid metabolism, many of which are redox sensitive and regulated by ROS.
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Dasarathy S. Is the adiponectin-AMPK-mitochondrial axis involved in progression of nonalcoholic fatty liver disease? Hepatology 2014; 60:22-5. [PMID: 24644076 PMCID: PMC4482450 DOI: 10.1002/hep.27134] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 03/11/2014] [Indexed: 02/06/2023]
Affiliation(s)
- Srinivasan Dasarathy
- Department of Gastroenterology, Hepatology and Pathobiology, Cleveland Clinic, Cleveland, OH
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34
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Bieghs V, Hendrikx T, van Gorp PJ, Verheyen F, Guichot YD, Walenbergh SMA, Jeurissen MLJ, Gijbels M, Rensen SS, Bast A, Plat J, Kalhan SC, Koek GH, Leitersdorf E, Hofker MH, Lütjohann D, Shiri-Sverdlov R. The cholesterol derivative 27-hydroxycholesterol reduces steatohepatitis in mice. Gastroenterology 2013; 144:167-178.e1. [PMID: 23041327 DOI: 10.1053/j.gastro.2012.09.062] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 08/16/2012] [Accepted: 09/19/2012] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Non-alcoholic steatohepatitis is characterized by hepatic steatosis with inflammation. Although steatosis is benign and reversible, inflammation can increase liver damage. Hepatic inflammation has been associated with accumulation of cholesterol in lysosomes of Kupffer cells. 27-Hydroxycholesterol (27HC), a derivative of cholesterol formed by CYP27A1, can mobilize cholesterol from the lysosomes to the cytoplasm. We investigated whether 27HC can change the intracellular distribution cholesterol and reduce hepatic inflammation in mice. METHODS We transplanted bone marrow from irradiated wild-type or Cyp27a1(-/-) mice to mice that do not express the low density lipoprotein receptor (Ldlr(-/-)), which are hyperlipidemic; 9 weeks later, mice were fed either regular chow or a high-fat, high-cholesterol (HFC) diet for 3 months. In a separate experiment, Ldlr(-/-) mice were given subcutaneous injections of 27HC and placed on regular chow or HFC diets for 3 weeks. Blood and liver tissues samples were collected and analyzed for intracellular cholesterol distribution and inflammation. RESULTS In Ldlr(-/-) mice that received bone marrow transplants from Cyp27a1(-/-) mice, lysosomes of Kupfer cells had a greater accumulation of cholesterol than those of mice that received bone marrow from wild-type mice, after the HFC diet. Liver histology and gene expression analyses showed increased inflammation and liver damage in mice given bone marrow transplants from Cyp27a1(-/-) mice and placed on the HFC diet. Administration of 27HC to Ldlr(-/-) mice, following the HFC diet, reduced the accumulation of lysosomal cholesterol and hepatic inflammation, compared with mice that were not given 27HC. CONCLUSIONS Accumulation of cholesterol in lysosomes of Kupfer cells promotes hepatic inflammation in mice. The cholesterol derivative 27HC reduces accumulation of cholesterol in lysosomes and might be used to treat non-alcoholic steatohepatitis.
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Affiliation(s)
- Veerle Bieghs
- Department of Molecular Genetics, Maastricht University, Maastricht, the Netherlands
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Kalhan SC, Hanson RW. Resurgence of serine: an often neglected but indispensable amino Acid. J Biol Chem 2012; 287:19786-91. [PMID: 22566694 DOI: 10.1074/jbc.r112.357194] [Citation(s) in RCA: 202] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Serine is generally classified as a nutritionally nonessential (dispensable) amino acid, but metabolically, serine is indispensible and plays an essential role in several cellular processes. Serine is the major source of one-carbon units for methylation reactions that occur via the generation of S-adenosylmethionine. The regulation of serine metabolism in mammalian tissues is thus of critical importance for the control of methyl group transfer. In addition to the well known role of d-serine in the brain, l-serine has recently been implicated in breast cancer and other tumors due in part to the genomic copy number gain for 3-phosphoglycerate dehydrogenase, the enzyme that controls the entry of glycolytic intermediates into the pathway of serine synthesis. Here, we review recent information regarding the synthesis of serine and the regulation of its metabolism and discuss the role played by phosphoenolpyruvate carboxykinase in this process.
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Affiliation(s)
- Satish C Kalhan
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio 44195, USA.
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Methionine and protein metabolism in non-alcoholic steatohepatitis: evidence for lower rate of transmethylation of methionine. Clin Sci (Lond) 2011; 121:179-89. [PMID: 21446920 DOI: 10.1042/cs20110060] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hepatic metabolism of methionine is the source of cysteine, the precursor of glutathione, the major intracellular antioxidant in the body. Methionine also is the immediate precursor of SAM (S-adenosylmethionine) the key methyl donor for phosphatidylcholine synthesis required for the export of VLDL (very-low-density lipoprotein) triacylglycerols (triglycerides) from the liver. We have examined the kinetics of methionine, its transmethylation and trans-sulfuration with estimates of whole body rate of protein turnover and urea synthesis in clinically stable biopsy-confirmed subjects with NASH (non-alcoholic steatohepatitis). Subjects with NASH were more insulin-resistant and had significantly higher plasma concentrations of usCRP (ultrasensitive C-reactive protein), TNFα (tumour necrosis factor α) and other inflammatory cytokines. There was no significant effect of insulin resistance and NASH on whole body rate of protein turnover [phenylalanine Ra (rate of appearance)] and on the rate of urea synthesis. The rates of methylation of homocysteine and transmethylation of methionine were significantly lower in NASH compared with controls. There was no difference in the rate of trans-sulfuration of methionine between the two groups. Enteric mixed nutrient load resulted in a significant increase in all the measured parameters of methionine kinetics. Heterozygosity for MTHFR (5,10-methylene-tetrahydrofolate reductase) (677C→T) did not have an impact on methionine metabolism. We speculate that, as a result of oxidant stress possibly due to high fatty acid oxidation, the activity of methionine adenosyltransferase is attenuated resulting in a lower rate of transmethylation of methionine and of SAM synthesis. These results are the first evidence for perturbed metabolism of methionine in NASH in humans and provide a rationale for the development of targeted intervention strategies.
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Elevated hepatic fatty acid oxidation, high plasma fibroblast growth factor 21, and fasting bile acids in nonalcoholic steatohepatitis. Eur J Gastroenterol Hepatol 2011; 23:382-8. [PMID: 21448070 PMCID: PMC3493151 DOI: 10.1097/meg.0b013e328345c8c7] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Data from studies in patients with nonalcoholic steatohepatitis (NASH) suggest an increased hepatic fatty acid oxidation. We have previously shown higher fasting plasma bile acid concentrations in patients with NASH. In-vivo and in-vitro studies suggest that bile acids by binding to peroxisome proliferator-activated receptor α activate fibroblast growth factor 21 (FGF21) and increase hepatic fatty acid oxidation. METHODS Plasma bile acid levels were quantified in healthy controls (n=38) and patients with biopsy-proven NASH (n=36). Plasma concentration of fatty acids, β-hydroxybutyrate, insulin, glucose, leptin, alanine aminotransferase, FGF21, and 8-hydroxydeoxyguanosine, a measure of oxidative stress, were measured in 16 healthy controls and 10 patients with NASH in the fasted state and in response to 3 h of infusion of intralipid. In a subgroup of these patients (n=6 each), plasma ceramide subspecies were quantified. RESULTS Fasting plasma bile acids, FGF21, and leptin concentrations were significantly higher in patients with NASH. In response to intralipid infusion there was an increase in plasma β-hydroxybutyrate and free fatty acid levels in both controls and NASH; however, the ratio of β-hydroxybutyrate/free fatty acid was higher in NASH (P=0.02). Plasma FGF21 concentration increased in response to intralipid in patients with NASH only (P<0.01). Plasma leptin, insulin, glucose, and alanine transferase concentrations did not change in either group after infusion of intralipid. Increase in total ceramides in response to intralipid was greater in NASH. CONCLUSION Elevated bile acids and FGF21 may be responsible for the higher hepatic fatty acid oxidation in NASH.
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Kalhan SC, Guo L, Edmison J, Dasarathy S, McCullough AJ, Hanson RW, Milburn M. Plasma metabolomic profile in nonalcoholic fatty liver disease. Metabolism 2011; 60:404-13. [PMID: 20423748 PMCID: PMC2950914 DOI: 10.1016/j.metabol.2010.03.006] [Citation(s) in RCA: 393] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 03/05/2010] [Accepted: 03/08/2010] [Indexed: 02/06/2023]
Abstract
The plasma profile of subjects with nonalcoholic fatty liver disease (NAFLD), steatosis, and steatohepatitis (NASH) was examined using an untargeted global metabolomic analysis to identify specific disease-related patterns and to identify potential noninvasive biomarkers. Plasma samples were obtained after an overnight fast from histologically confirmed nondiabetic subjects with hepatic steatosis (n = 11) or NASH (n = 24) and were compared with healthy, age- and sex-matched controls (n = 25). Subjects with NAFLD were obese, were insulin resistant, and had higher plasma concentrations of homocysteine and total cysteine and lower plasma concentrations of total glutathione. Metabolomic analysis showed markedly higher levels of glycocholate, taurocholate, and glycochenodeoxycholate in subjects with NAFLD. Plasma concentrations of long-chain fatty acids were lower and concentrations of free carnitine, butyrylcarnitine, and methylbutyrylcarnitine were higher in NASH. Several glutamyl dipeptides were higher whereas cysteine-glutathione levels were lower in NASH and steatosis. Other changes included higher branched-chain amino acids, phosphocholine, carbohydrates (glucose, mannose), lactate, pyruvate, and several unknown metabolites. Random forest analysis and recursive partitioning of the metabolomic data could separate healthy subjects from NAFLD with an error rate of approximately 8% and separate NASH from healthy controls with an error rate of 4%. Hepatic steatosis and steatohepatitis could not be separated using the metabolomic profile. Plasma metabolomic analysis revealed marked changes in bile salts and in biochemicals related to glutathione in subjects with NAFLD. Statistical analysis identified a panel of biomarkers that could effectively separate healthy controls from NAFLD and healthy controls from NASH. These biomarkers can potentially be used to follow response to therapeutic interventions.
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Affiliation(s)
- Satish C Kalhan
- Department of Pathobiology, Cleveland Clinic, Cleveland, OH 44195, USA.
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