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Kim J, Seo S, Kim TY. Metabolic deuterium oxide (D 2O) labeling in quantitative omics studies: A tutorial review. Anal Chim Acta 2023; 1242:340722. [PMID: 36657897 DOI: 10.1016/j.aca.2022.340722] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/25/2022] [Accepted: 12/13/2022] [Indexed: 12/15/2022]
Abstract
Mass spectrometry (MS) is an invaluable tool for sensitive detection and characterization of individual biomolecules in omics studies. MS combined with stable isotope labeling enables the accurate and precise determination of quantitative changes occurring in biological samples. Metabolic isotope labeling, wherein isotopes are introduced into biomolecules through biosynthetic metabolism, is one of the main labeling strategies. Among the precursors employed in metabolic isotope labeling, deuterium oxide (D2O) is cost-effective and easy to implement in any biological systems. This tutorial review aims to explain the basic principle of D2O labeling and its applications in omics research. D2O labeling incorporates D into stable C-H bonds in various biomolecules, including nucleotides, proteins, lipids, and carbohydrates. Typically, D2O labeling is performed at low enrichment of 1%-10% D2O, which causes subtle changes in the isotopic distribution of a biomolecule, instead of the complete separation between labeled and unlabeled samples in a mass spectrum. D2O labeling has been employed in various omics studies to determine the metabolic flux, turnover rate, and relative quantification. Moreover, the advantages and challenges of D2O labeling and its future prospects in quantitative omics are discussed. The economy, versatility, and convenience of D2O labeling will be beneficial for the long-term omics studies for higher organisms.
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Affiliation(s)
- Jonghyun Kim
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju, 61005, South Korea
| | - Seungwoo Seo
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju, 61005, South Korea
| | - Tae-Young Kim
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju, 61005, South Korea.
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2
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Sadana P, Edler M, Aghayev M, Arias-Alvarado A, Cohn E, Ilchenko S, Piontkivska H, Pillai JA, Kashyap S, Kasumov T. Metabolic labeling unveils alterations in the turnover of HDL-associated proteins during diabetes progression in mice. Am J Physiol Endocrinol Metab 2022; 323:E480-E491. [PMID: 36223521 PMCID: PMC9722254 DOI: 10.1152/ajpendo.00158.2022] [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: 07/06/2022] [Revised: 10/04/2022] [Accepted: 10/05/2022] [Indexed: 01/21/2023]
Abstract
Several aspects of diabetes pathophysiology and complications result from hyperglycemia-induced alterations in the structure and function of plasma proteins. Furthermore, insulin has a significant influence on protein metabolism by affecting both the synthesis and degradation of proteins in various tissues. To understand the role of progressive hyperglycemia on plasma proteins, in this study, we measured the turnover rates of high-density lipoprotein (HDL)-associated proteins in control (chow diet), prediabetic [a high-fat diet (HFD) for 8 wk] or diabetic [HFD for 8 wk with low-dose streptozotocin (HFD + STZ) in weeks 5-8 of HFD] C57BL/6J mice using heavy water (2H2O)-based metabolic labeling approach. Compared with control mice, HFD and HFD + STZ mice showed elevations of fasting plasma glucose levels in the prediabetic and diabetic range, respectively. Furthermore, the HFD and HFD + STZ mice showed increased hepatic triglyceride (TG) levels, total plasma cholesterol, and plasma TGs. The kinetics of 40 proteins were quantified using the proteome dynamics method, which revealed an increase in the fractional synthesis rate (FSR) of HDL-associated proteins in the prediabetic mice compared with control mice, and a decrease in FSR in the diabetic mice. The pathway analysis revealed that proteins with altered turnover rates were involved in acute-phase response, lipid metabolism, and coagulation. In conclusion, prediabetes and diabetes have distinct effects on the turnover rates of HDL proteins. These findings suggest that an early dysregulation of the HDL proteome dynamics can provide mechanistic insights into the changes in protein levels in these conditions.NEW & NOTEWORTHY This study is the first to examine the role of gradual hyperglycemia during diabetes disease progression on HDL-associated protein dynamics in the prediabetes and diabetic mice. Our results show that the fractional synthesis rate of HDL-associated proteins increased in the prediabetic mice whereas it decreased in the diabetic mice compared with control mice. These kinetic changes can help to elucidate the mechanism of altered protein levels and HDL dysfunction during diabetes disease progression.
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Affiliation(s)
- Prabodh Sadana
- Department of Pharmacy Practice, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio
| | - Melissa Edler
- Department of Anthropology, Kent State University, Kent, Ohio
| | - Mirjavid Aghayev
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio
| | - Andrea Arias-Alvarado
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio
| | - Emilie Cohn
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio
| | - Serguei Ilchenko
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio
| | - Helen Piontkivska
- Department of Biological Sciences, and Brain Health Research Institute, Kent State University, Kent, Ohio
| | - Jagan A Pillai
- Lou Ruvo Center for Brain Health, Cleveland Clinic Foundation, Cleveland, Ohio
| | | | - Takhar Kasumov
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio
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3
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Zhang Z, TeSlaa T, Xu X, Zeng X, Yang L, Xing G, Tesz GJ, Clasquin MF, Rabinowitz JD. Serine catabolism generates liver NADPH and supports hepatic lipogenesis. Nat Metab 2021; 3:1608-1620. [PMID: 34845393 PMCID: PMC8721747 DOI: 10.1038/s42255-021-00487-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 09/30/2021] [Indexed: 12/15/2022]
Abstract
Carbohydrate can be converted into fat by de novo lipogenesis, a process upregulated in fatty liver disease. Chemically, de novo lipogenesis involves polymerization and reduction of acetyl-CoA, using NADPH as the electron donor. The feedstocks used to generate acetyl-CoA and NADPH in lipogenic tissues remain, however, unclear. Here we show using stable isotope tracing in mice that de novo lipogenesis in adipose is supported by glucose and its catabolism via the pentose phosphate pathway to make NADPH. The liver, in contrast, derives acetyl-CoA for lipogenesis from acetate and lactate, and NADPH from folate-mediated serine catabolism. Such NADPH generation involves the cytosolic serine pathway in liver running in the opposite direction to that observed in most tissues and tumours, with NADPH made by the SHMT1-MTHFD1-ALDH1L1 reaction sequence. SHMT inhibition decreases hepatic lipogenesis. Thus, liver folate metabolism is distinctively wired to support cytosolic NADPH production and lipogenesis. More generally, while the same enzymes are involved in fat synthesis in liver and adipose, different substrates are used, opening the door to tissue-specific pharmacological interventions.
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Affiliation(s)
- Zhaoyue Zhang
- Department of Chemistry, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Tara TeSlaa
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Xincheng Xu
- Department of Chemistry, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Xianfeng Zeng
- Department of Chemistry, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Lifeng Yang
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Gang Xing
- Pfizer Inc. Internal Medicine, Cambridge, MA, USA
| | | | | | - Joshua D Rabinowitz
- Department of Chemistry, Princeton University, Princeton, NJ, USA.
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.
- Ludwig Institute for Cancer Research, Princeton Branch, Princeton University, Princeton, NJ, USA.
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4
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Kanhai KMS, Goulooze SC, van der Grond J, Harms AC, Hankemeier T, Verma A, Dent G, Chavez J, Meijering H, Groeneveld GJ. Kinetics of myelin breakdown products: A labeling study in patients with progressive multiple sclerosis. Clin Transl Sci 2021; 15:638-648. [PMID: 34799987 PMCID: PMC8932820 DOI: 10.1111/cts.13181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 05/10/2021] [Accepted: 10/06/2021] [Indexed: 11/26/2022] Open
Abstract
The majority of disease modifying therapies for multiple sclerosis (MS) reduce inflammation, but do no’t target remyelination. Development of remyelinating therapies will benefit from a method to quantify myelin kinetics in patients with MS. We labeled myelin in vivo with deuterium, and modeled kinetics of myelin breakdown products β‐galactosylceramide (β‐GalC) and N‐Octadecanoyl‐sulfatide (NO‐Sulf). Five patients with MS received 120 ml 70% D2O daily for 70 days and were compared with six healthy subjects who previously received the same procedure. Mass spectrometry and compartmental modeling were used to quantify the turnover rate of β‐GalC and NO‐Sulf in cerebrospinal fluid (CSF). Turnover rate constants of the fractions of β‐GalC and NO‐Sulf with non‐negligible turnover were 0.00186 and 0.00714, respectively, in both healthy subjects and patients with MS. The turnover half‐life of β‐GalC and NO‐Sulf was calculated as 373 days and 96.5 days, respectively. The effect of MS on the NO‐Sulf (49.4% lower fraction with non‐negligible turnover) was more pronounced compared to the effect on β‐GalC turnover (18.3% lower fraction with non‐negligible turnover). Kinetics of myelin breakdown products in the CSF are different in patients with MS compared with healthy subjects. This may be caused by slower myelin production in these patients, by a higher level of degradation of a more stable component of myelin, or, most likely, by a combination of these two processes. Labeling myelin breakdown products is a useful method that can be used to quantify myelin turnover in patients with progressive MS and can therefore be used in proof‐of‐concept studies with remyelination therapies.
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Affiliation(s)
- Kawita M S Kanhai
- Centre for Human Drug Research, Leiden, The Netherlands.,Prothya Biosolutions, Amsterdam, The Netherlands
| | - Sebastiaan C Goulooze
- Centre for Human Drug Research, Leiden, The Netherlands.,Department of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | | | - Amy C Harms
- Prothya Biosolutions, Amsterdam, The Netherlands.,Radiology Department, Leiden University Medical Center, Leiden, The Netherlands
| | - Thomas Hankemeier
- Department of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands.,Netherlands Metabolomics Centre, Leiden, The Netherlands
| | - Ajay Verma
- Yumanity Pharmaceuticals, Boston, Massachusetts, USA
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Mammary Development in Gilts at One Week Postnatal Is Related to Plasma Lysine Concentration at 24 h after Birth, but Not Colostrum Dose. Animals (Basel) 2021; 11:ani11102867. [PMID: 34679896 PMCID: PMC8532886 DOI: 10.3390/ani11102867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/07/2021] [Accepted: 09/16/2021] [Indexed: 01/25/2023] Open
Abstract
Simple Summary A relationship exists between a female’s early nutritional environment and her ability to produce milk when she lactates as an adult. Colostrum is the first milk available to neonates after birth. We hypothesized that differing levels of colostrum stimulate differences in very early mammary development. Despite differences in weight at 24 h and 7 days, mammary morphological development and DNA content was not found to be different between gilts fed a high versus low dose of colostrum. The rate of mammary gland protein and DNA synthesis over the first week was not different between the groups. Circulating levels of amino acids were determined after 24 h of colostrum feeding, and levels of circulating lysine were found to be related to average daily gain and mammary DNA synthetic rate. Moreover, the level of lysine was related to a lower ratio of DNA to protein synthesis, suggesting that higher lysine favored cell division versus differentiation (by leaving the cell cycle). Further studies are needed in this area. Abstract Perinatal nutrition affects future milk production. The number of mammary epithelial cells affect milk production capacity. Therefore, it was hypothesized that the level of colostrum intake affects the proliferation rate and the total number of mammary epithelial cells in the gland. The ratio of newly synthesized protein to newly synthesized DNA reflects the relative amount of cellular differentiation to cell division. The study objective was to determine the relationship between the level of colostrum intake and 24 h-level of circulating amino acid, glucose and insulin with mammary parenchyma histological features, cell division and protein synthesis over the first week postnatal. One of two standardized doses of a homogenate colostrum sample, 10% (n = 8) and 20% (n = 8) of birth bodyweight, was fed to gilts over the first 24 h postnatal. Gilts were administered deuterium oxide immediately after birth and daily to label newly synthesized DNA and proteins. Gilts were euthanized on postnatal day seven, and DNA and protein were isolated from mammary parenchyma. DNA and protein fractional synthesis (f) and fractional synthetic rate (FSR) were calculated using mass isotopomer distribution analysis. The ratio of protein f and FSR to DNA f and FSR were calculated and used to indicate the relative amounts of differentiation to cell division. Mammary morphological development was also analyzed by measuring the parenchymal epithelial area and the stromal and epithelial proliferation index on postnatal day seven. Colostrum dose was not related to any of the variables used to evaluate mammary development. However, plasma lysine levels at 24 h postnatal were positively related to average daily gain (ADG; r = 0.54, p = 0.05), DNA f (r = 0.57; p = 0.03) and DNA FSR (r = 0.57; p = 0.03) in mammary parenchyma. Plasma lysine was inversely related to the ratio of protein to DNA f and FSR (r = −0.56; p = 0.04). ADG was related to the parenchymal epithelial area and DNA and protein f and FSR (p < 0.05). These relationships support the idea that the nutritional environment affects early mammary development and that higher lysine levels in the perinatal period favored a greater degree of cell division versus differentiation in mammary of neonatal pigs and thus, warrant further investigations.
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Maharjan P, Beitia A, Weil J, Suesuttajit N, Hilton K, Caldas J, Umberson C, Martinez D, Kong B, Owens CM, Coon C. Woody breast myopathy broiler show age-dependent adaptive differential gene expression in Pectoralis major and altered in-vivo triglyceride kinetics in adipogenic tissues. Poult Sci 2021; 100:101092. [PMID: 34087697 PMCID: PMC8182436 DOI: 10.1016/j.psj.2021.101092] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 02/17/2021] [Accepted: 03/04/2021] [Indexed: 11/26/2022] Open
Abstract
A study was conducted to understand the differentially expressed genes in Pectoralis (P) major under woody breast (WB) myopathy condition in a high yielding broiler strain using RNA-sequencing at the growing (d 21) and finishing (d 42 and d 56) grow-out ages. Follow-up study was conducted to understand the in vivo triglyceride (TG) synthesis (d 49) occurring in adipogenic tissues using deuterium oxide (2H2O) as a metabolic tracer. Results indicated the top physiological systems affected in myopathy broiler were related to the musculo-skeletal system (d 21, 42, and 56) and cardiovascular system (d 42 and 56). Ubiquitin-specific proteases are expressed higher in myopathy broiler at d 21 (OTUD1) and d 42 (SACS) that potentially indicated higher degradation of muscle protein occurring at those ages. While genes related to transcription factors and muscle cell differentiation (ZNF234, BTG2) and muscle growth (IGF1) were upregulated with myopathy broiler suggesting concurrent muscle fiber regeneration. The downregulation of PYGB and MGAM genes related to carbohydrate transport and metabolism at d 42 potentially indicated nutrient-deficient state of myopathy affected fibers; whereas the nutrient-deficient physiological state of cells seemed to be counteracted by up-regulation of genes related to carbohydrate (ALDOB, GPD1L2) at d 56. There was a reduced (P < 0.05) in vivo TG synthesis in liver of the myopathy broiler (0.123 %/hr) compared to non-myopathy broiler (0.197 %/hr). The majority of TG synthesized in liver with myopathy broiler could conceivably be delivered to P. major (rather than to abdominal fat pad storage) to fulfil the increased energy need of muscle cells (via TG lipolysis and fatty acid [FA] oxidation). The increased utilization of FAs in the WB affected muscle could result in reduced secretion of FAs into blood circulation leading to sub-optimal availability of FAs for re-esterification for TG synthesis in liver. Results indicated that myopathy broiler at later age (d 56) of grow-out period were synchronously going through adaptive physiological processes of feedback responses to adverse cellular states.
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Affiliation(s)
- Pramir Maharjan
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | | | - Jordan Weil
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Nawin Suesuttajit
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Katie Hilton
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | | | - Cole Umberson
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Diego Martinez
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Byungwhi Kong
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Casey M Owens
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Craig Coon
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA.
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7
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Measurement of lipogenic flux by deuterium resolved mass spectrometry. Nat Commun 2021; 12:3756. [PMID: 34145255 PMCID: PMC8213799 DOI: 10.1038/s41467-021-23958-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 05/25/2021] [Indexed: 01/09/2023] Open
Abstract
De novo lipogenesis (DNL) is disrupted in a wide range of human disease. Thus, quantification of DNL may provide insight into mechanisms and guide interventions if it can be performed rapidly and noninvasively. DNL flux is commonly measured by 2H incorporation into fatty acids following deuterated water (2H2O) administration. However, the sensitivity of this approach is limited by the natural abundance of 13C, which masks detection of 2H by mass spectrometry. Here we report that high-resolution Orbitrap gas-chromatography mass-spectrometry resolves 2H and 13C fatty acid mass isotopomers, allowing DNL to be quantified using lower 2H2O doses and shorter experimental periods than previously possible. Serial measurements over 24-hrs in mice detects the nocturnal activation of DNL and matches a 3H-water method in mice with genetic activation of DNL. Most importantly, DNL is detected in overnight-fasted humans in less than an hour and is responsive to feeding during a 4-h study. Thus, 2H specific MS provides the ability to study DNL in settings that are currently impractical.
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8
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Arias-Alvarado A, Aghayev M, Ilchenko S, Rachdaoui N, Lepp J, Tsai TH, Zhang GF, Previs S, Kasumov T. Measuring acetyl-CoA and acetylated histone turnover in vivo: Effect of a high fat diet. Anal Biochem 2020; 615:114067. [PMID: 33340539 DOI: 10.1016/j.ab.2020.114067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/08/2020] [Accepted: 12/13/2020] [Indexed: 11/24/2022]
Abstract
Cellular availability of acetyl-CoA, a central intermediate of metabolism, regulates histone acetylation. The impact of a high-fat diet (HFD) on the turnover rates of acetyl-CoA and acetylated histones is unknown. We developed a method for simultaneous measurement of acetyl-CoA and acetylated histones kinetics using a single 2H2O tracer, and used it to examine effect of HFD-induced perturbations on hepatic histone acetylation in LDLR-/- mice, a mouse model of non-alcoholic fatty liver disease (NAFLD). Mice were given 2H2O in the drinking water and the kinetics of hepatic acetyl-CoA, histones, and acetylated histones were quantified based on their 2H-labeling. Consumption of a high fat Western-diet (WD) for twelve weeks led to decreased acetylation of hepatic histones (p< 0.05), as compared to a control diet. These changes were associated with 1.5-3-fold increased turnover rates of histones without any change in acetyl-CoA flux. Acetylation significantly reduced the stability of histones and the turnover rates of acetylated peptides were correlated with the number of acetyl groups in neighboring lysine sites. We conclude that 2H2O-method can be used to study metabolically controlled histone acetylation and acetylated histone turnover in vivo.
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Affiliation(s)
- Andrea Arias-Alvarado
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, 44272, USA
| | - Mirjavid Aghayev
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, 44272, USA
| | - Serguei Ilchenko
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, 44272, USA
| | - Nadia Rachdaoui
- Department of Animal Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Josephine Lepp
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, 44272, USA
| | - Tsung-Heng Tsai
- Department of Mathematical Sciences, Kent State University, Kent, OH, 44242, USA
| | - Guo-Fang Zhang
- Division of Division of Endocrinology, Metabolism and Nutrition, Duke Molecular Physiology Institute, And Department of Medicine, Duke University, Durham, NC, 27701, USA
| | - Stephen Previs
- Merck & Co., Inc, 2000 Galloping Hill Rd, Kenilworth, NJ, 07033, USA
| | - Takhar Kasumov
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, 44272, USA; Departments of Gastroenterology, Hepatology and Nutrition, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA.
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9
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Downes DP, Kasumov T, Daurio NA, Wood NB, Previs MJ, Sheth PR, McLaren DG, Previs SF. Isotope Fractionation during Gas Chromatography Can Enhance Mass Spectrometry-Based Measures of 2H-Labeling of Small Molecules. Metabolites 2020; 10:E474. [PMID: 33233825 PMCID: PMC7699861 DOI: 10.3390/metabo10110474] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/06/2020] [Accepted: 11/12/2020] [Indexed: 11/16/2022] Open
Abstract
Stable isotope tracers can be used to quantify the activity of metabolic pathways. Specifically, 2H-water is quite versatile, and its incorporation into various products can enable measurements of carbohydrate, lipid, protein and nucleic acid kinetics. However, since there are limits on how much 2H-water can be administered and since some metabolic processes may be slow, it is possible that one may be challenged with measuring small changes in isotopic enrichment. We demonstrate an advantage of the isotope fractionation that occurs during gas chromatography, namely, setting tightly bounded integration regions yields a powerful approach for determining isotope ratios. We determined how the degree of isotope fractionation, chromatographic peak width and mass spectrometer dwell time can increase the apparent isotope labeling. Relatively simple changes in the logic surrounding data acquisition and processing can enhance gas chromatography-mass spectrometry measures of low levels of 2H-labeling, this is especially useful when asymmetrical peaks are recorded at low signal:background. Although we have largely focused attention on alanine (which is of interest in studies of protein synthesis), it should be possible to extend the concepts to other analytes and/or hardware configurations.
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Affiliation(s)
- Daniel P. Downes
- Department of Chemistry, Merck & Co., Inc., Kenilworth, NJ 07033, USA; (D.P.D.); (N.A.D.); (P.R.S.); (D.G.M.)
| | - Takhar Kasumov
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH 44272, USA;
| | - Natalie A. Daurio
- Department of Chemistry, Merck & Co., Inc., Kenilworth, NJ 07033, USA; (D.P.D.); (N.A.D.); (P.R.S.); (D.G.M.)
| | - Neil B. Wood
- Department of Molecular Physiology & Biophysics, University of Vermont, Burlington, VT 05405, USA; (N.B.W.); (M.J.P.)
| | - Michael J. Previs
- Department of Molecular Physiology & Biophysics, University of Vermont, Burlington, VT 05405, USA; (N.B.W.); (M.J.P.)
| | - Payal R. Sheth
- Department of Chemistry, Merck & Co., Inc., Kenilworth, NJ 07033, USA; (D.P.D.); (N.A.D.); (P.R.S.); (D.G.M.)
| | - David G. McLaren
- Department of Chemistry, Merck & Co., Inc., Kenilworth, NJ 07033, USA; (D.P.D.); (N.A.D.); (P.R.S.); (D.G.M.)
| | - Stephen F. Previs
- Department of Chemistry, Merck & Co., Inc., Kenilworth, NJ 07033, USA; (D.P.D.); (N.A.D.); (P.R.S.); (D.G.M.)
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10
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Kelly KL, Reagan WJ, Sonnenberg GE, Clasquin M, Hales K, Asano S, Amor PA, Carvajal-Gonzalez S, Shirai N, Matthews MD, Li KW, Hellerstein MK, Vera NB, Ross TT, Cappon G, Bergman A, Buckeridge C, Sun Z, Qejvanaj EZ, Schmahai T, Beebe D, Pfefferkorn JA, Esler WP. De novo lipogenesis is essential for platelet production in humans. Nat Metab 2020; 2:1163-1178. [PMID: 32929234 DOI: 10.1038/s42255-020-00272-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 08/06/2020] [Indexed: 02/08/2023]
Abstract
Acetyl-CoA carboxylase (ACC) catalyses the first step of de novo lipogenesis (DNL). Pharmacologic inhibition of ACC has been of interest for therapeutic intervention in a wide range of diseases. We demonstrate here that ACC and DNL are essential for platelet production in humans and monkeys, but in not rodents or dogs. During clinical evaluation of a systemically distributed ACC inhibitor, unexpected dose-dependent reductions in platelet count were observed. While platelet count reductions were not observed in rat and dog toxicology studies, subsequent studies in cynomolgus monkeys recapitulated these platelet count reductions with a similar concentration response to that in humans. These studies, along with ex vivo human megakaryocyte maturation studies, demonstrate that platelet lowering is a consequence of DNL inhibition likely to result in impaired megakaryocyte demarcation membrane formation. These observations demonstrate that while DNL is a minor quantitative contributor to global lipid balance in humans, DNL is essential to specific lipid pools of physiological importance.
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Affiliation(s)
- Kenneth L Kelly
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, USA
| | - William J Reagan
- Drug Safety Research and Development, Pfizer Inc., Groton, CT, USA
| | - Gabriele E Sonnenberg
- Early Clinical Development, Pfizer Worldwide Research and Development, Cambridge, MA, USA
| | - Michelle Clasquin
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, USA
| | - Katherine Hales
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, USA
| | - Shoh Asano
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, USA
| | - Paul A Amor
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, USA
| | | | - Norimitsu Shirai
- Drug Safety Research and Development, Pfizer Inc., Groton, CT, USA
| | - Marcy D Matthews
- Department of Nutritional Sciences and Toxicology, University of California at Berkeley, Berkeley, CA, USA
| | - Kelvin W Li
- Department of Nutritional Sciences and Toxicology, University of California at Berkeley, Berkeley, CA, USA
| | - Marc K Hellerstein
- Department of Nutritional Sciences and Toxicology, University of California at Berkeley, Berkeley, CA, USA
| | - Nicholas B Vera
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, USA
| | - Trenton T Ross
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, USA
| | - Gregg Cappon
- Drug Safety Research and Development, Pfizer Inc., Groton, CT, USA
| | - Arthur Bergman
- Early Clinical Development, Pfizer Worldwide Research and Development, Cambridge, MA, USA
| | - Clare Buckeridge
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, USA
| | - Zhongyuan Sun
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, USA
| | - Enida Ziso Qejvanaj
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, USA
| | | | - David Beebe
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, USA
| | - Jeffrey A Pfefferkorn
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, USA
| | - William P Esler
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, USA.
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11
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Shahkhatuni AA, Shahkhatuni AG, Mamyan SS, Ananikov VP, Harutyunyan AS. Proton-deuterium exchange of acetone catalyzed in imidazolium-based ionic liquid-D 2O mixtures. RSC Adv 2020; 10:32485-32489. [PMID: 35516517 PMCID: PMC9056620 DOI: 10.1039/d0ra04206d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/11/2020] [Indexed: 01/31/2023] Open
Abstract
The reaction of the proton–deuterium exchange of acetone in imidazolium-based ionic liquid (IL)–deuterium oxide mixtures was studied in detail via NMR spectroscopy. Certain ILs exhibit considerable catalytic properties and contribute to the course of reaction up to the complete deuteration. The efficiency of deuterium exchange crucially depends on the features of ILs; the type of anion and chain length of cation. The linear secondary isotope effects on the NMR chemical shifts of the 13C atoms in acetone were observed depending on the deuteration level of the molecule. The reaction of the proton–deuterium exchange of acetone in imidazolium-based ionic liquid (IL)–deuterium oxide mixtures was studied in detail via NMR spectroscopy.![]()
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Affiliation(s)
- Astghik A Shahkhatuni
- Molecule Structure Research Center, STCOPC NAS RA Azatutian Ave. 26 Yerevan 0014 Armenia
| | - Aleksan G Shahkhatuni
- Molecule Structure Research Center, STCOPC NAS RA Azatutian Ave. 26 Yerevan 0014 Armenia
| | - Suren S Mamyan
- Molecule Structure Research Center, STCOPC NAS RA Azatutian Ave. 26 Yerevan 0014 Armenia
| | - Valentine P Ananikov
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences Leninsky Prospect 47 Moscow 119991 Russian Federation
| | - Arpine S Harutyunyan
- Molecule Structure Research Center, STCOPC NAS RA Azatutian Ave. 26 Yerevan 0014 Armenia
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12
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Temporal Dynamics of High-Density Lipoprotein Proteome in Diet-Controlled Subjects with Type 2 Diabetes. Biomolecules 2020; 10:biom10040520. [PMID: 32235466 PMCID: PMC7226298 DOI: 10.3390/biom10040520] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/18/2020] [Accepted: 03/28/2020] [Indexed: 12/15/2022] Open
Abstract
We examined the effect of mild hyperglycemia on high-density lipoprotein (HDL) metabolism and kinetics in diet-controlled subjects with type 2 diabetes (T2D). 2H2O-labeling coupled with mass spectrometry was applied to quantify HDL cholesterol turnover and HDL proteome dynamics in subjects with T2D (n = 9) and age- and BMI-matched healthy controls (n = 8). The activities of lecithin–cholesterol acyltransferase (LCAT), cholesterol ester transfer protein (CETP), and the proinflammatory index of HDL were quantified. Plasma adiponectin levels were reduced in subjects with T2D, which was directly associated with suppressed ABCA1-dependent cholesterol efflux capacity of HDL. The fractional catabolic rates of HDL cholesterol, apolipoprotein A-II (ApoA-II), ApoJ, ApoA-IV, transthyretin, complement C3, and vitamin D-binding protein (all p < 0.05) were increased in subjects with T2D. Despite increased HDL flux of acute-phase HDL proteins, there was no change in the proinflammatory index of HDL. Although LCAT and CETP activities were not affected in subjects with T2D, LCAT was inversely associated with blood glucose and CETP was inversely associated with plasma adiponectin. The degradation rates of ApoA-II and ApoA-IV were correlated with hemoglobin A1c. In conclusion, there were in vivo impairments in HDL proteome dynamics and HDL metabolism in diet-controlled patients with T2D.
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13
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Kloehn J, McConville MJ. Analysis of the Physiological and Metabolic State of Leishmania Using Heavy Water Labeling. Methods Mol Biol 2020; 2116:587-609. [PMID: 32221944 DOI: 10.1007/978-1-0716-0294-2_35] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
This protocol describes the use of heavy water (2H2O) labeling to determine the growth rate and metabolic state of Leishmania parasites in culture and in infected animals. In vitro labeling studies are undertaken by cultivating defined parasite developmental stages in standard medium supplemented with 5% 2H2O, resulting in the incorporation of deuterium (2H) into a range of metabolic precursors used in macromolecule (DNA, RNA, protein, lipid, and glycan) synthesis. The rate of turnover of different parasite macromolecules can subsequently be determined by analysis of deuterium enrichment in the different constituents of these macromolecules by gas chromatography-mass spectrometry (GC-MS). To measure the growth rate and physiological state of parasite stages in lesion tissue, infected mice were provided with 9% 2H2O in their drinking water for various periods of time and 2H-enrichment in the macromolecular constituents of isolated lesion-derived parasite stages determined by GC-MS. This protocol provides quantitative information on key cellular processes, such as replication (DNA turnover), transcription (RNA turnover), translation (protein turnover), membrane biogenesis (lipid turnover), and central carbon metabolism (glycan turnover) that define the growth state and phenome of different parasite stages in vitro and in vivo. This approach can be used to assess the impact of host immune responses on parasite growth and physiology (using different Leishmania strains/species, mouse lines), characterize different parasite populations during chronic and acute infections, and assess parasite responses to drug treatments. It is also broadly applicable to other microbial pathogens.
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MESH Headings
- Animals
- DNA, Protozoan/analysis
- DNA, Protozoan/chemistry
- DNA, Protozoan/metabolism
- Deuterium Oxide/chemistry
- Disease Models, Animal
- Female
- Gas Chromatography-Mass Spectrometry/methods
- Humans
- Isotope Labeling/methods
- Leishmania mexicana/isolation & purification
- Leishmania mexicana/metabolism
- Leishmaniasis, Cutaneous/diagnosis
- Leishmaniasis, Cutaneous/immunology
- Leishmaniasis, Cutaneous/parasitology
- Leishmaniasis, Cutaneous/pathology
- Life Cycle Stages/physiology
- Metabolomics/methods
- Mice
- Polysaccharides/analysis
- Polysaccharides/chemistry
- Polysaccharides/metabolism
- Protozoan Proteins/analysis
- Protozoan Proteins/chemistry
- Protozoan Proteins/metabolism
- RNA, Protozoan/analysis
- RNA, Protozoan/chemistry
- RNA, Protozoan/metabolism
- Skin/parasitology
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Affiliation(s)
- Joachim Kloehn
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva, Switzerland
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, VIC, Australia
| | - Malcolm J McConville
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, VIC, Australia.
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14
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Daurio NA, Wang Y, Chen Y, Zhou H, Carballo-Jane E, Mane J, Rodriguez CG, Zafian P, Houghton A, Addona G, McLaren DG, Zhang R, Shyong BJ, Bateman K, Downes DP, Webb M, Kelley DE, Previs SF. Spatial and temporal studies of metabolic activity: contrasting biochemical kinetics in tissues and pathways during fasted and fed states. Am J Physiol Endocrinol Metab 2019; 316:E1105-E1117. [PMID: 30912961 DOI: 10.1152/ajpendo.00459.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The regulation of nutrient homeostasis, i.e., the ability to transition between fasted and fed states, is fundamental in maintaining health. Since food is typically consumed over limited (anabolic) periods, dietary components must be processed and stored to counterbalance the catabolic stress that occurs between meals. Herein, we contrast tissue- and pathway-specific metabolic activity in fasted and fed states. We demonstrate that knowledge of biochemical kinetics that is obtained from opposite ends of the energetic spectrum can allow mechanism-based differentiation of healthy and disease phenotypes. Rat models of type 1 and type 2 diabetes serve as case studies for probing spatial and temporal patterns of metabolic activity via [2H]water labeling. Experimental designs that capture integrative whole body metabolism, including meal-induced substrate partitioning, can support an array of research surrounding metabolic disease; the relative simplicity of the approach that is discussed here should enable routine applications in preclinical models.
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Affiliation(s)
- Natalie A Daurio
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Yichen Wang
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Ying Chen
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Haihong Zhou
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Ester Carballo-Jane
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Joel Mane
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Carlos G Rodriguez
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Peter Zafian
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Andrea Houghton
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - George Addona
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - David G McLaren
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Rena Zhang
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Bao Jen Shyong
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Kevin Bateman
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Daniel P Downes
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Maria Webb
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - David E Kelley
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Stephen F Previs
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
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15
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Chen Y, Berejnaia O, Liu J, Wang SP, Daurio NA, Yin W, Mayoral R, Petrov A, Kasumov T, Zhang GF, Previs SF, Kelley DE, McLaren DG. Quantifying ceramide kinetics in vivo using stable isotope tracers and LC-MS/MS. Am J Physiol Endocrinol Metab 2018; 315:E416-E424. [PMID: 29509438 DOI: 10.1152/ajpendo.00457.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Numerous studies have implicated dyslipidemia as a key factor in mediating insulin resistance. Ceramides have received special attention since their levels are inversely associated with normal insulin signaling and positively associated with factors that are involved in cardiometabolic disease. Despite the growing literature surrounding ceramide biology, there are limited data regarding the activity of ceramide synthesis and turnover in vivo. Herein, we demonstrate the ability to measure ceramide kinetics by coupling the administration of [2H]water with LC-MS/MS analyses. As a "proof-of-concept" we determined the effect of a diet-induced alteration on ceramide flux; studies also examined the effect of myriocin (a known inhibitor of serine palmitoyltransferase, the first step in sphingosine biosynthesis). Our data suggest that one can estimate ceramide synthesis and draw conclusions regarding the source of fatty acids; we discuss caveats in regards to method development in this area.
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Affiliation(s)
- Ying Chen
- MRL, Merck & Co., Inc., Kenilworth, New Jersey
| | | | - Jinqi Liu
- MRL, Merck & Co., Inc., Kenilworth, New Jersey
| | | | | | - Wu Yin
- MRL, Merck & Co., Inc., Kenilworth, New Jersey
| | | | | | - Takhar Kasumov
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio
| | - Guo-Fang Zhang
- Division of Endocrinology, Metabolism and Nutrition, Duke Molecular Physiology Institute, and Department of Medicine, Duke University , Durham, North Carolina
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16
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Previs SF, Herath K, Nawrocki AR, Rodriguez CG, Slipetz D, Singh SB, Kang L, Bhat G, Roddy TP, Conarello S, Terebetski J, Erion MD, Kelley DE. Using [ 2H]water to quantify the contribution of de novo palmitate synthesis in plasma: enabling back-to-back studies. Am J Physiol Endocrinol Metab 2018; 315:E63-E71. [PMID: 29351479 DOI: 10.1152/ajpendo.00010.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An increased contribution of de novo lipogenesis (DNL) may play a role in cases of dyslipidemia and adipose accretion; this suggests that inhibition of fatty acid synthesis may affect clinical phenotypes. Since it is not clear whether modulation of one step in the lipogenic pathway is more important than another, the use of tracer methods can provide a deeper level of insight regarding the control of metabolic activity. Although [2H]water is generally considered a reliable tracer for quantifying DNL in vivo (it yields a homogenous and quantifiable precursor labeling), the relatively long half-life of body water is thought to limit the ability of performing repeat studies in the same subjects; this can create a bottleneck in the development and evaluation of novel therapeutics for inhibiting DNL. Herein, we demonstrate the ability to perform back-to-back studies of DNL using [2H]water. However, this work uncovered special circumstances that affect the data interpretation, i.e., it is possible to obtain seemingly negative values for DNL. Using a rodent model, we have identified a physiological mechanism that explains the data. We show that one can use [2H]water to test inhibitors of DNL by performing back-to-back studies in higher species [i.e., treat nonhuman primates with platensimycin, an inhibitor of fatty acid synthase]; studies also demonstrate the unsuitability of [13C]acetate.
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Affiliation(s)
- Stephen F Previs
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Kithsiri Herath
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Andrea R Nawrocki
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Carlos G Rodriguez
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Deborah Slipetz
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Sheo B Singh
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Ling Kang
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Gowri Bhat
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Thomas P Roddy
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Stacey Conarello
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Jenna Terebetski
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Mark D Erion
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - David E Kelley
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
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17
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Kashyap SR, Osme A, Ilchenko S, Golizeh M, Lee K, Wang S, Bena J, Previs SF, Smith JD, Kasumov T. Glycation Reduces the Stability of ApoAI and Increases HDL Dysfunction in Diet-Controlled Type 2 Diabetes. J Clin Endocrinol Metab 2018; 103:388-396. [PMID: 29077935 PMCID: PMC5800833 DOI: 10.1210/jc.2017-01551] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 10/20/2017] [Indexed: 12/16/2022]
Abstract
CONTEXT Hyperglycemia plays a key role in the pathogenesis of cardiovascular complications of diabetes. Type 2 diabetes mellitus (T2DM) is associated with high-density lipoprotein (HDL) dysfunction and increased degradation of apolipoprotein I (ApoAI). The mechanism(s) of these changes is largely unknown. OBJECTIVE To study the role of hyperglycemia-induced glycation on ApoAI kinetics and stability in patients with diet-controlled T2DM. DESIGN 2H2O-metabolic labeling approach was used to study ApoAI turnover in patients with diet-controlled T2DM [n = 9 (5 F); 59.3 ± 8.5 years] and matched healthy controls [n = 8 (4 F); 50.7 ± 11.6 years]. The effect of Amadori glycation on in vivo ApoAI stability and the antioxidant and cholesterol efflux properties of HDL were assessed using a proteomics approach and in vitro assays. RESULTS Patients with T2DM had increased turnover of ApoAI and impaired cholesterol efflux and antioxidant properties of HDL. Glycated hemoglobin was negatively correlated with the half-life of ApoAI and cholesterol efflux function of HDL. Proteomics analysis identified several nonenzymatic early (Amadori) glycations of ApoAI at lysine sites. The kinetics analysis of glycated and native ApoAI peptides in patients with T2DM revealed that glycation resulted in a threefold shorter ApoAI half-life. CONCLUSIONS The 2H2O method allowed the detection of early in vivo impairments in HDL metabolism and function that were related to hyperglycemia-induced glycation of ApoAI in T2DM.
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Affiliation(s)
- Sangeeta R. Kashyap
- Department of Endocrinology and Metabolism, Cleveland Clinic, Cleveland, Ohio 44195
| | - Abdullah Osme
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Serguei Ilchenko
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Makan Golizeh
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Kwangwon Lee
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Shuhui Wang
- Department of Cellular & Molecular Medicine, Cleveland Clinic, Cleveland, Ohio 44195
| | - James Bena
- Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio 44195
| | | | - Jonathan D. Smith
- Department of Cellular & Molecular Medicine, Cleveland Clinic, Cleveland, Ohio 44195
| | - Takhar Kasumov
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio 44272
- Department of Hepatology, Cleveland Clinic, Cleveland, Ohio 44195
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18
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Golizeh M, Lee K, Ilchenko S, Ösme A, Bena J, Sadygov RG, Kashyap SR, Kasumov T. Increased serotransferrin and ceruloplasmin turnover in diet-controlled patients with type 2 diabetes. Free Radic Biol Med 2017; 113:461-469. [PMID: 29079528 PMCID: PMC5739305 DOI: 10.1016/j.freeradbiomed.2017.10.373] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 09/22/2017] [Accepted: 10/22/2017] [Indexed: 01/07/2023]
Abstract
Type 2 diabetes mellitus (T2DM) is associated with oxidative stress and perturbed iron metabolism. Serotransferrin (Trf) and ceruloplasmin (Cp) are two key proteins involved in iron metabolism and anti-oxidant defense. Non-enzymatic glycation and oxidative modification of plasma proteins are known to occur under hyperglycemia and oxidative stress. In this study, shotgun proteomics and 2H2O-based metabolic labeling were used to characterize post-translational modifications and assess the kinetics of Trf and Cp in T2DM patients and matched controls in vivo. Six early lysine (Amadori) and one advanced arginine glycation were detected in Trf. No glycation, but five asparagine deamidations, were found in Cp. T2DM patients had increased fractional catabolic rates of both Trf and Cp that correlated with HbA1c (p < 0.05). The glycated Trf population was subject to an even faster degradation compared to the total Trf pool, suggesting that hyperglycemia contributed to an increased Trf degradation in T2DM patients. Enhanced production of Trf and Cp kept their levels stable. The changes in Trf and Cp turnover were associated with increased systemic oxidative stress without any alteration in iron status in T2DM. These findings can help better understand the potential role of altered Trf and Cp metabolism in the pathogenesis of T2DM and other diseases.
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Affiliation(s)
- Makan Golizeh
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Kwangwon Lee
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Serguei Ilchenko
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Abdullah Ösme
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, United States
| | - James Bena
- Section of Biostatistics, Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH, United States
| | - Rovshan G Sadygov
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States
| | - Sangeeta R Kashyap
- Department of Endocrinology, Cleveland Clinic, Cleveland, OH, United States
| | - Takhar Kasumov
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, United States; Department of Endocrinology, Cleveland Clinic, Cleveland, OH, United States.
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19
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Rachdaoui N, Li L, Willard B, Kasumov T, Previs S, Sarkar D. Turnover of histones and histone variants in postnatal rat brain: effects of alcohol exposure. Clin Epigenetics 2017; 9:117. [PMID: 29075360 PMCID: PMC5654083 DOI: 10.1186/s13148-017-0416-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Accepted: 10/04/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Alcohol consumption during pregnancy is a significant public health problem and can result in a continuum of adverse outcomes to the fetus known as fetal alcohol spectrum disorders (FASD). Subjects with FASD show significant neurological deficits, ranging from microencephaly, neurobehavioral, and mental health problems to poor social adjustment and stress tolerance. Neurons are particularly sensitive to alcohol exposure. The neurotoxic action of alcohol, i.e., through ROS production, induces DNA damage and neuronal cell death by apoptosis. In addition, epigenetics, including DNA methylation, histone posttranslational modifications (PTMs), and non-coding RNA, play an important role in the neuropathology of FASD. However, little is known about the temporal dynamics and kinetics of histones and their PTMs in FASD. RESULTS We examined the effects of postnatal alcohol exposure (PAE), an animal model of human third-trimester equivalent, on the kinetics of various histone proteins in two distinct brain regions, the frontal cortex, and the hypothalamus, using in vivo 2H2O-labeling combined with mass spectrometry-based proteomics. We show that histones have long half-lives that are in the order of days. We also show that H3.3 and H2Az histone variants have faster turnovers than canonical histones and that acetylated histones, in general, have a faster turnover than unmodified and methylated histones. Our work is the first to show that PAE induces a differential reduction in turnover rates of histones in both brain regions studied. These alterations in histone turnover were associated with increased DNA damage and decreased cell proliferation in postnatal rat brain. CONCLUSION Alterations in histone turnover might interfere with histone deposition and chromatin stability, resulting in deregulated cell-specific gene expression and therefore contribute to the development of the neurological disorders associated with FASD. Using in vivo 2H2O-labeling and mass spectrometry-based proteomics might help in the understanding of histone turnover following alcohol exposure and could be of great importance in enabling researchers to identify novel targets and/or biomarkers for the prevention and management of fetal alcohol spectrum disorders.
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Affiliation(s)
- Nadia Rachdaoui
- Department of Animal Sciences, Rutgers Endocrine Research Program, Rutgers, the State University of New Jersey, 67 Poultry Farm Lane, New Brunswick, NJ 08901 USA
| | - Ling Li
- Department of Research Core Services, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44106 USA
| | - Belinda Willard
- Department of Research Core Services, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44106 USA
| | - Takhar Kasumov
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH 44272 USA
| | - Stephen Previs
- Cardiometabolic Disease, Merck & Co., Inc, Kenilworth, NJ USA
| | - Dipak Sarkar
- Department of Animal Sciences, Rutgers Endocrine Research Program, Rutgers, the State University of New Jersey, 67 Poultry Farm Lane, New Brunswick, NJ 08901 USA
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20
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Daurio NA, Wang SP, Chen Y, Zhou H, McLaren DG, Roddy TP, Johns DG, Milot D, Kasumov T, Erion MD, Kelley DE, Previs SF. Enhancing Studies of Pharmacodynamic Mechanisms via Measurements of Metabolic Flux: Fundamental Concepts and Guiding Principles for Using Stable Isotope Tracers. J Pharmacol Exp Ther 2017; 363:80-91. [DOI: 10.1124/jpet.117.241091] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Accepted: 06/14/2017] [Indexed: 11/22/2022] Open
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21
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Farthing DE, Buxbaum NP, Lucas PJ, Maglakelidze N, Oliver B, Wang J, Hu K, Castro E, Bare CV, Gress RE. Comparing DNA enrichment of proliferating cells following administration of different stable isotopes of heavy water. Sci Rep 2017. [PMID: 28642474 PMCID: PMC5481421 DOI: 10.1038/s41598-017-04404-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Deuterated water (2H2O) is a label commonly used for safe quantitative measurement of deuterium enrichment into DNA of proliferating cells. More recently, it has been used for labeling proteins and other biomolecules. Our in vitro - in vivo research reports important stable isotopic labeling enrichment differences into the DNA nucleosides and their isotopologues (e.g. deoxyadenosine (dA) M + 1, dA M + 2, dA M + 3), as well as tumor cell proliferation effects for various forms of commercially available stable heavy water (2H2O, H218O, and 2H218O). Using an in vitro mouse thymus tumor cell line, we determined that H218O provides superior DNA labeling enrichment quantitation, as measured by GC-positive chemical ionization (PCI)-MS/MS. In addition, at higher but physiologically relevant doses, both 2H218O and 2H2O down modulated mouse thymus tumor cell proliferation, whereas H218O water had no observable effects on cell proliferation. The in vivo labeling studies, where normal mouse bone marrow cells (i.e. high turnover) were evaluated post labeling, demonstrated DNA enrichments concordant with measurements from the in vitro studies. Our research also reports a headspace-GC-NCI-MS method, which rapidly and quantitatively measures stable heavy water levels in total body water.
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Affiliation(s)
- Don E Farthing
- National Institutes of Health (NIH), National Cancer Institute (NCI), Experimental Transplantation and Immunology (ETIB), 10 Center Drive, Bethesda, MD, 20892, United States.
| | - Nataliya P Buxbaum
- National Institutes of Health (NIH), National Cancer Institute (NCI), Experimental Transplantation and Immunology (ETIB), 10 Center Drive, Bethesda, MD, 20892, United States
| | - Philip J Lucas
- National Institutes of Health (NIH), National Cancer Institute (NCI), Experimental Transplantation and Immunology (ETIB), 10 Center Drive, Bethesda, MD, 20892, United States
| | - Natella Maglakelidze
- National Institutes of Health (NIH), National Cancer Institute (NCI), Experimental Transplantation and Immunology (ETIB), 10 Center Drive, Bethesda, MD, 20892, United States
| | - Brittany Oliver
- OCRT&ME, 10 Center Drive, Bethesda, MD, 20814, United States
| | - Jiun Wang
- National Institutes of Health (NIH), National Cancer Institute (NCI), Experimental Transplantation and Immunology (ETIB), 10 Center Drive, Bethesda, MD, 20892, United States
| | - Kevin Hu
- National Institutes of Health (NIH), National Cancer Institute (NCI), Experimental Transplantation and Immunology (ETIB), 10 Center Drive, Bethesda, MD, 20892, United States
| | - Ehydel Castro
- National Institutes of Health (NIH), National Cancer Institute (NCI), Experimental Transplantation and Immunology (ETIB), 10 Center Drive, Bethesda, MD, 20892, United States
| | - Catherine V Bare
- National Institutes of Health (NIH), National Cancer Institute (NCI), Experimental Transplantation and Immunology (ETIB), 10 Center Drive, Bethesda, MD, 20892, United States
| | - Ronald E Gress
- National Institutes of Health (NIH), National Cancer Institute (NCI), Experimental Transplantation and Immunology (ETIB), 10 Center Drive, Bethesda, MD, 20892, United States
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Murphy BA, Tadin-Strapps M, Jensen K, Mogg R, Liaw A, Herath K, Bhat G, McLaren DG, Previs SF, Pinto S. siRNA-mediated inhibition of SREBP cleavage-activating protein reduces dyslipidemia in spontaneously dysmetabolic rhesus monkeys. Metabolism 2017; 71:202-212. [PMID: 28521874 DOI: 10.1016/j.metabol.2017.02.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 02/26/2017] [Accepted: 02/27/2017] [Indexed: 01/07/2023]
Abstract
BACKGROUND SREBP cleavage-activating protein (SCAP) is a cholesterol binding endoplasmic reticulum (ER) membrane protein that is required to activate SREBP transcription factors. SREBPs regulate genes involved in lipid biosynthesis. They also influence lipid clearance by modulating the expression of LDL receptor (LDLR) and proprotein convertase subtilisin/kexin type 9 (PCSK9) genes. Inhibiting SCAP decreases circulating PCSK9, triglycerides (TG), and LDL-cholesterol (LDL-C), both in vitro and in vivo. Type 2 diabetics with dyslipidemia are at high risk for cardiovascular diseases. These patients present a unique pathophysiological lipid profile characterized by moderately elevated LDL-C, elevated TG and reduced HDL-cholesterol (HDL-C). The spontaneous dysmetabolic rhesus monkey model (DysMet RhM) recapitulates this human dyslipidemia and therefore is an attractive preclinical model to evaluate SCAP inhibition as a therapy for this disease population. The objective to of this study was to assess the effect of SCAP inhibition on the lipid profile of DysMet RhM. METHOD We assessed the effect of inhibiting hepatic SCAP on the lipid profile of DysMet RhM using an siRNA encapsulated lipid nanoparticle (siRNA-LNP). RESULTS The SCAP siRNA-LNP significantly reduced LDL-C, PCSK9 and TG in DysMet RhM; LDL-C was reduced by ≥20%, circulating PCSK9 by 30-40% and TG by >25%. These changes by the SCAP siRNA-LNP agree with the predicted effect of SCAP inhibition and reduced SREBP tone on these endpoints. CONCLUSION These data demonstrate that a SCAP siRNA-LNP improved the lipid profile in a clinically relevant preclinical disease model and provide evidence for SCAP inhibition as a therapy for diabetic dyslipidemic patients.
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Affiliation(s)
- Beth Ann Murphy
- Pharmacology, Merck &Co. Inc., 2000 Galloping Hill Rd., Kenilworth, NJ 07033, USA.
| | - Marija Tadin-Strapps
- Genetics and Pharmacogenomics, Merck & Co. Inc., 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Kristian Jensen
- Cardiometabolic Disease, Merck & Co. Inc., 2000 Galloping Hill Rd., Kenilworth, NJ 07033, USA
| | - Robin Mogg
- Biostatistics, Merck & Co. Inc., 351 North Sumneytown Pike, North Wales, PA 19454, USA
| | - Andy Liaw
- Biostatistics, Merck & Co. Inc., 126 E. Lincoln Avenue, PO Box 2000, Rahway, NJ 07065, USA
| | - Kithsiri Herath
- Cardiometabolic Disease, Merck & Co. Inc., 2000 Galloping Hill Rd., Kenilworth, NJ 07033, USA
| | - Gowri Bhat
- Cardiometabolic Disease, Merck & Co. Inc., 2000 Galloping Hill Rd., Kenilworth, NJ 07033, USA
| | - David G McLaren
- Pharmacology, Merck &Co. Inc., 2000 Galloping Hill Rd., Kenilworth, NJ 07033, USA
| | - Stephen F Previs
- Cardiometabolic Disease, Merck & Co. Inc., 2000 Galloping Hill Rd., Kenilworth, NJ 07033, USA
| | - Shirly Pinto
- Cardiometabolic Disease, Merck & Co. Inc., 2000 Galloping Hill Rd., Kenilworth, NJ 07033, USA
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Darrah R, Bederman I, Vitko M, Valerio DM, Drumm ML, Hodges CA. Growth deficits in cystic fibrosis mice begin in utero prior to IGF-1 reduction. PLoS One 2017; 12:e0175467. [PMID: 28384265 PMCID: PMC5383306 DOI: 10.1371/journal.pone.0175467] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 03/27/2017] [Indexed: 12/16/2022] Open
Abstract
Growth deficits are common in cystic fibrosis (CF), but their cause is complex, with contributions from exocrine pancreatic insufficiency, pulmonary complications, gastrointestinal obstructions, and endocrine abnormalities. The CF mouse model displays similar growth impairment despite exocrine pancreatic function and in the absence of chronic pulmonary infection. The high incidence of intestinal obstruction in the CF mouse has been suggested to significantly contribute to the observed growth deficits. Previous studies by our group have shown that restoration of the cystic fibrosis transmembrane conductance regulator (CFTR) in the intestinal epithelium prevents intestinal obstruction but does not improve growth. In this study, we further investigate growth deficits in CF and gut-corrected CF mice by assessing insulin-like growth factor 1 (IGF-1). IGF-1 levels were significantly decreased in CF and gut-corrected CF adult mice compared to wildtype littermates and were highly correlated with weight. Interestingly, perinatal IGF-1 levels were not significantly different between CF and wildtype littermates, even though growth deficits in CF mice could be detected late in gestation. Since CFTR has been suggested to play a role in water and nutrient exchange in the placenta through its interaction with aquaporins, we analyzed placental aquaporin expression in late-gestation CF and control littermates. While significant differences were observed in Aquaporin 9 expression in CF placentas in late gestation, there was no evidence of placental fluid exchange differences between CF and control littermates. The results from this study indicate that decreased IGF-1 levels are highly correlated with growth in CF mice, independent of CF intestinal obstruction. However, the perinatal growth deficits that are observed in CF mice are not due to decreased IGF-1 levels or differences in placenta-mediated fluid exchange. Further investigation is necessary to understand the etiology of early growth deficits in CF, as growth has been shown to be a significant factor in disease outcomes.
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Affiliation(s)
- Rebecca Darrah
- Frances Payne Bolton School of Nursing, Case Western Reserve University, Cleveland, Ohio, United States of America
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Ilya Bederman
- Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Megan Vitko
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Dana M. Valerio
- Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Mitchell L. Drumm
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
- Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Craig A. Hodges
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
- Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio, United States of America
- * E-mail:
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24
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Jensen KK, Tadin-Strapps M, Wang SP, Hubert J, Kan Y, Ma Y, McLaren DG, Previs SF, Herath KB, Mahsut A, Liaw A, Wang S, Stout SJ, Keohan C, Forrest G, Coelho D, Yendluri S, Williams S, Koser M, Bartz S, Akinsanya KO, Pinto S. Dose-dependent effects of siRNA-mediated inhibition of SCAP on PCSK9, LDLR, and plasma lipids in mouse and rhesus monkey. J Lipid Res 2016; 57:2150-2162. [PMID: 27707816 PMCID: PMC5321219 DOI: 10.1194/jlr.m071498] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 10/01/2016] [Indexed: 01/03/2023] Open
Abstract
SREBP cleavage-activating protein (SCAP) is a key protein in the regulation of lipid metabolism and a potential target for treatment of dyslipidemia. SCAP is required for activation of the transcription factors SREBP-1 and -2. SREBPs regulate the expression of genes involved in fatty acid and cholesterol biosynthesis, and LDL-C clearance through the regulation of LDL receptor (LDLR) and PCSK9 expression. To further test the potential of SCAP as a novel target for treatment of dyslipidemia, we used siRNAs to inhibit hepatic SCAP expression and assess the effect on PCSK9, LDLR, and lipids in mice and rhesus monkeys. In mice, robust liver Scap mRNA knockdown (KD) was achieved, accompanied by dose-dependent reduction in SREBP-regulated gene expression, de novo lipogenesis, and plasma PCSK9 and lipids. In rhesus monkeys, over 90% SCAP mRNA KD was achieved resulting in approximately 75, 50, and 50% reduction of plasma PCSK9, TG, and LDL-C, respectively. Inhibition of SCAP function was demonstrated by reduced expression of SREBP-regulated genes and de novo lipogenesis. In conclusion, siRNA-mediated inhibition of SCAP resulted in a significant reduction in circulating PCSK9 and LDL-C in rodent and primate models supporting SCAP as a novel target for the treatment of dyslipidemia.
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Affiliation(s)
| | | | | | - James Hubert
- Cardiometabolic Disease Merck & Co. Inc., Kenilworth, NJ
| | - Yanqing Kan
- Cardiometabolic Disease Merck & Co. Inc., Kenilworth, NJ
| | - Yong Ma
- Sirna Therapeutics Merck & Co. Inc., San Francisco, CA
| | | | | | | | - Ablatt Mahsut
- Cardiometabolic Disease Merck & Co. Inc., Kenilworth, NJ
| | - Andy Liaw
- Biostatistics, Merck & Co. Inc., Rahway, NJ
| | | | - Steven J Stout
- Cardiometabolic Disease Merck & Co. Inc., Kenilworth, NJ
| | | | | | - David Coelho
- Sirna Therapeutics Merck & Co. Inc., San Francisco, CA
| | | | | | - Martin Koser
- RNA Therapeutics, Merck & Co. Inc., West Point, PA
| | - Steven Bartz
- Business Development and Licensing, Merck & Co. Inc., San Francisco, CA
| | | | - Shirly Pinto
- Cardiometabolic Disease Merck & Co. Inc., Kenilworth, NJ
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25
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Singh SB, Kang L, Nawrocki AR, Zhou D, Wu M, Previs S, Miller C, Liu H, Hines CDG, Madeira M, Cao J, Herath K, Wang L, Kelley DE, Li C, Guan HP. The Fatty Acid Synthase Inhibitor Platensimycin Improves Insulin Resistance without Inducing Liver Steatosis in Mice and Monkeys. PLoS One 2016; 11:e0164133. [PMID: 27695056 PMCID: PMC5047649 DOI: 10.1371/journal.pone.0164133] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 09/20/2016] [Indexed: 01/12/2023] Open
Abstract
Objectives Platensimycin (PTM) is a natural antibiotic produced by Streptomyces platensis that selectively inhibits bacterial and mammalian fatty acid synthase (FAS) without affecting synthesis of other lipids. Recently, we reported that oral administration of PTM in mouse models (db/db and db/+) with high de novo lipogenesis (DNL) tone inhibited DNL and enhanced glucose oxidation, which in turn led to net reduction of liver triglycerides (TG), reduced ambient glucose, and improved insulin sensitivity. The present study was conducted to explore translatability and the therapeutic potential of FAS inhibition for the treatment of diabetes in humans. Methods We tested PTM in animal models with different DNL tones, i.e. intrinsic synthesis rates, which vary among species and are regulated by nutritional and disease states, and confirmed glucose-lowering efficacy of PTM in lean NHPs with quantitation of liver lipid by MRS imaging. To understand the direct effect of PTM on liver metabolism, we performed ex vivo liver perfusion study to compare FAS inhibitor and carnitine palmitoyltransferase 1 (CPT1) inhibitor. Results The efficacy of PTM is generally reproduced in preclinical models with DNL tones comparable to humans, including lean and established diet-induced obese (eDIO) mice as well as non-human primates (NHPs). Similar effects of PTM on DNL reduction were observed in lean and type 2 diabetic rhesus and lean cynomolgus monkeys after acute and chronic treatment of PTM. Mechanistically, PTM lowers plasma glucose in part by enhancing hepatic glucose uptake and glycolysis. Teglicar, a CPT1 inhibitor, has similar effects on glucose uptake and glycolysis. In sharp contrast, Teglicar but not PTM significantly increased hepatic TG production, thus caused liver steatosis in eDIO mice. Conclusions These findings demonstrate unique properties of PTM and provide proof-of-concept of FAS inhibition having potential utility for the treatment of diabetes and related metabolic disorders.
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Affiliation(s)
- Sheo B. Singh
- Departments of Discovery Chemistry, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
- * E-mail: (SBS); (HPG)
| | - Ling Kang
- Department of Cardiometabolic Disease, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
| | - Andrea R. Nawrocki
- Department of Pharmacology, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
| | - Dan Zhou
- Department of Pharmacology, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
| | - Margaret Wu
- Department of Cardiometabolic Disease, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
| | - Stephen Previs
- Department of Cardiometabolic Disease, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
| | - Corey Miller
- Department of Imaging and Biomarker, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
| | - Haiying Liu
- Department of Imaging and Biomarker, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
| | - Catherine D. G. Hines
- Department of Translational Imaging Biomarkers, Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA, 19486, United States of America
| | - Maria Madeira
- Department of PKPD, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
| | - Jin Cao
- Department of Imaging and Biomarker, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
| | - Kithsiri Herath
- Department of Cardiometabolic Disease, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
| | - Liangsu Wang
- Department of Cardiometabolic Disease, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
| | - David E. Kelley
- Department of Cardiometabolic Disease, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
| | - Cai Li
- Department of Pharmacology, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
| | - Hong-Ping Guan
- Department of Cardiometabolic Disease, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ, 07033, United States of America
- * E-mail: (SBS); (HPG)
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26
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Eberl A, Altendorfer-Kroath T, Kollmann D, Birngruber T, Sinner F, Raml R, Magnes C. Determination of 2H-enrichment of rat brain interstitial fluid and rat plasma by headspace-gas-chromatography – quadrupole-mass-spectrometry. Anal Biochem 2016; 509:130-134. [DOI: 10.1016/j.ab.2016.07.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 07/06/2016] [Accepted: 07/07/2016] [Indexed: 11/17/2022]
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27
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Li L, Bebek G, Previs SF, Smith JD, Sadygov RG, McCullough AJ, Willard B, Kasumov T. Proteome Dynamics Reveals Pro-Inflammatory Remodeling of Plasma Proteome in a Mouse Model of NAFLD. J Proteome Res 2016; 15:3388-404. [PMID: 27439437 DOI: 10.1021/acs.jproteome.6b00601] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is associated with an increased risk of cardiovascular disease. Because the liver is the major source of circulatory proteins, it is not surprising that hepatic disease could lead to alterations in the plasma proteome, which are therein implicated in atherosclerosis. The current study used low-density lipoprotein receptor-deficient (LDLR(-/-)) mice to examine the impact of Western diet (WD)-induced NAFLD on plasma proteome homeostasis. Using a (2)H2O-metabolic labeling method, we found that a WD led to a proinflammatory distribution of circulatory proteins analyzed in apoB-depleted plasma, which was attributed to an increased production. The fractional turnover rates of short-lived proteins that are implicated in stress-response, lipid metabolism, and transport functions were significantly increased with WD (P < 0.05). Pathway analyses revealed that alterations in plasma proteome dynamics were related to the suppression of hepatic PPARα, which was confirmed based on reduced gene and protein expression of PPARα in mice fed a WD. These changes were associated with ∼4-fold increase (P < 0.0001) in the proinflammatory property of apoB-depleted plasma. In conclusion, the proteome dynamics method reveals proinflammatory remodeling of the plasma proteome relevant to liver disease. The approach used herein may provide a useful metric of in vivo liver function and better enable studies of novel therapies surrounding NAFLD and other diseases.
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Affiliation(s)
| | - Gurkan Bebek
- Department of Nutrition, Center for Proteomics and Bioinformatics, Electrical Engineering and Computer Science Department, Case Western Reserve University , Cleveland, Ohio 44195, United States
| | - Stephen F Previs
- School of Medicine, Case Western Reserve University , Cleveland, Ohio 44106, United States
| | | | - Rovshan G Sadygov
- The University of Texas Medical Branch , Galveston, Texas 77555, United States
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28
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Li L, Zhang GF, Lee K, Lopez R, Previs SF, Willard B, McCullough A, Kasumov T. A Western diet induced NAFLD in LDLR(-/)(-) mice is associated with reduced hepatic glutathione synthesis. Free Radic Biol Med 2016; 96:13-21. [PMID: 27036364 PMCID: PMC5297627 DOI: 10.1016/j.freeradbiomed.2016.03.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 03/24/2016] [Accepted: 03/25/2016] [Indexed: 12/11/2022]
Abstract
Oxidative stress plays a key role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Glutathione is the major anti-oxidant involved in cellular oxidative defense, however there are currently no simple non-invasive methods for assessing hepatic glutathione metabolism in patients with NAFLD. As a primary source of plasma glutathione, liver plays an important role in interorgan glutathione homeostasis. In this study, we have tested the hypothesis that measurements of plasma glutathione turnover could be used to assess the hepatic glutathione metabolism in LDLR(-/)(-) mice, a mouse model of diet-induced NAFLD. Mice were fed a standard low fat diet (LFD) or a high fat diet containing cholesterol (a Western type diet (WD)). The kinetics of hepatic and plasma glutathione were quantified using the (2)H2O metabolic labeling approach. Our results show that a WD leads to reduced fractional synthesis rates (FSR) of hepatic (25%/h in LFD vs. 18%/h in WD, P<0.05) and plasma glutathione (43%/h in LFD vs. 21%/h in WD, P<0.05), without any significant effect on their absolute production rates (PRs). WD-induced concordant changes in both hepatic and plasma glutathione turnover suggest that the plasma glutathione turnover measurements could be used to assess hepatic glutathione metabolism. The safety, simplicity, and low cost of the (2)H2O-based glutathione turnover approach suggest that this method has the potential for non-invasive probing of hepatic glutathione metabolism in patients with NAFLD and other diseases.
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Affiliation(s)
- Ling Li
- Department of Research Core Services, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Guo-Fang Zhang
- Department of Nutrition, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Kwangwon Lee
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, OH 44272, USA
| | - Rocio Lopez
- Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Stephen F Previs
- Merck Research Laboratories, 2000 Galloping Hill Road, Kenilworth, NJ 07033, USA
| | - Belinda Willard
- Department of Research Core Services, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Arthur McCullough
- Department of Hepatology and Gastroenterology, Digestive Disease Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Takhar Kasumov
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, OH 44272, USA; Department of Hepatology and Gastroenterology, Digestive Disease Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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29
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Lin JB, Mast N, Bederman IR, Li Y, Brunengraber H, Björkhem I, Pikuleva IA. Cholesterol in mouse retina originates primarily from in situ de novo biosynthesis. J Lipid Res 2015; 57:258-64. [PMID: 26630912 DOI: 10.1194/jlr.m064469] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Indexed: 12/18/2022] Open
Abstract
The retina, a thin tissue in the back of the eye, has two apparent sources of cholesterol: in situ biosynthesis and cholesterol available from the systemic circulation. The quantitative contributions of these two cholesterol sources to the retinal cholesterol pool are unknown and have been determined in the present work. A new methodology was used. Mice were given separately deuterium-labeled drinking water and chow containing 0.3% deuterium-labeled cholesterol. In the retina, the rate of total cholesterol input was 21 μg of cholesterol/g retina • day, of which 15 μg of cholesterol/g retina • day was provided by local biosynthesis and 6 μg of cholesterol/g retina • day was uptaken from the systemic circulation. Thus, local cholesterol biosynthesis accounts for the majority (72%) of retinal cholesterol input. We also quantified cholesterol input to mouse brain, the organ sharing important similarities with the retina. The rate of total cerebral cholesterol input was 121 μg of cholesterol/g brain • day with local biosynthesis providing 97% of total cholesterol input. Our work addresses a long-standing question in eye research and adds new knowledge to the potential use of statins (drugs that inhibit cholesterol biosynthesis) as therapeutics for age-related macular degeneration, a common blinding disease.
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Affiliation(s)
- Joseph B Lin
- Department of Ophthalmology and Visual Sciences,Case Western Reserve University, Cleveland, OH 44106
| | - Natalia Mast
- Department of Ophthalmology and Visual Sciences,Case Western Reserve University, Cleveland, OH 44106
| | - Ilya R Bederman
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH 44106
| | - Yong Li
- Department of Ophthalmology and Visual Sciences,Case Western Reserve University, Cleveland, OH 44106
| | - Henri Brunengraber
- Department of Nutrition, Case Western Reserve University, Cleveland, OH 44106
| | - Ingemar Björkhem
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska University Hospital, Karolinska Institute, Huddinge, Stockholm 141 86 Sweden
| | - Irina A Pikuleva
- Department of Ophthalmology and Visual Sciences,Case Western Reserve University, Cleveland, OH 44106
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30
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Guan HP, Yang X, Lu K, Wang SP, Castro-Perez JM, Previs S, Wright M, Shah V, Herath K, Xie D, Szeto D, Forrest G, Xiao JC, Palyha O, Sun LP, Andryuk PJ, Engel SS, Xiong Y, Lin S, Kelley DE, Erion MD, Davis HR, Wang L. Glucagon receptor antagonism induces increased cholesterol absorption. J Lipid Res 2015; 56:2183-95. [PMID: 26373568 DOI: 10.1194/jlr.m060897] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Indexed: 12/26/2022] Open
Abstract
Glucagon and insulin have opposing action in governing glucose homeostasis. In type 2 diabetes mellitus (T2DM), plasma glucagon is characteristically elevated, contributing to increased gluconeogenesis and hyperglycemia. Therefore, glucagon receptor (GCGR) antagonism has been proposed as a pharmacologic approach to treat T2DM. In support of this concept, a potent small-molecule GCGR antagonist (GRA), MK-0893, demonstrated dose-dependent efficacy to reduce hyperglycemia, with an HbA1c reduction of 1.5% at the 80 mg dose for 12 weeks in T2DM. However, GRA treatment was associated with dose-dependent elevation of plasma LDL-cholesterol (LDL-c). The current studies investigated the cause for increased LDL-c. We report findings that link MK-0893 with increased glucagon-like peptide 2 and cholesterol absorption. There was not, however, a GRA-related modulation of cholesterol synthesis. These findings were replicated using structurally diverse GRAs. To examine potential pharmacologic mitigation, coadministration of ezetimibe (a potent inhibitor of cholesterol absorption) in mice abrogated the GRA-associated increase of LDL-c. Although the molecular mechanism is unknown, our results provide a novel finding by which glucagon and, hence, GCGR antagonism govern cholesterol metabolism.
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Affiliation(s)
- Hong-Ping Guan
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Xiaodong Yang
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Ku Lu
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Sheng-Ping Wang
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Jose M Castro-Perez
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Stephen Previs
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Michael Wright
- Late Stage In Vitro Pharmacology, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Vinit Shah
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Kithsiri Herath
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Dan Xie
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Daphne Szeto
- Late Stage In Vivo Pharmacology, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Gail Forrest
- Late Stage In Vivo Pharmacology, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Jing Chen Xiao
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Oksana Palyha
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Li-Ping Sun
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Paula J Andryuk
- Clinical Research Department, Merck Research Laboratories, Rahway, NJ 07065
| | - Samuel S Engel
- Clinical Research Department, Merck Research Laboratories, Rahway, NJ 07065
| | - Yusheng Xiong
- Discovery Chemistry, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Songnian Lin
- Discovery Chemistry, Merck Research Laboratories, Kenilworth, NJ 07033
| | - David E Kelley
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Mark D Erion
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Harry R Davis
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
| | - Liangsu Wang
- Departments of Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ 07033
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Umpleby AM. HORMONE MEASUREMENT GUIDELINES: Tracing lipid metabolism: the value of stable isotopes. J Endocrinol 2015; 226:G1-10. [PMID: 26047888 DOI: 10.1530/joe-14-0610] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/04/2015] [Indexed: 01/14/2023]
Abstract
Labelling molecules with stable isotopes to create tracers has become a gold-standard method to study the metabolism of lipids and lipoproteins in humans. There are a range of techniques which use stable isotopes to measure fatty acid flux and oxidation, hepatic fatty synthesis, cholesterol absorption and synthesis and lipoprotein metabolism in humans. Stable isotope tracers are safe to use, enabling repeated studies to be undertaken and allowing studies to be undertaken in children and pregnant women. This review provides details of the most appropriate tracers to use, the techniques which have been developed and validated for measuring different aspects of lipid metabolism and some of the limitations of the methodology.
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Affiliation(s)
- A Margot Umpleby
- Diabetes and Metabolic MedicineFaculty of Health and Metabolic Sciences, University of Surrey, Leggett Building, Daphne Jackson Road, Manor Park, Guildford GU2 7WG, UK
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Naderer T, Heng J, Saunders EC, Kloehn J, Rupasinghe TW, Brown TJ, McConville MJ. Intracellular Survival of Leishmania major Depends on Uptake and Degradation of Extracellular Matrix Glycosaminoglycans by Macrophages. PLoS Pathog 2015; 11:e1005136. [PMID: 26334531 PMCID: PMC4559419 DOI: 10.1371/journal.ppat.1005136] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 08/10/2015] [Indexed: 02/02/2023] Open
Abstract
Leishmania parasites replicate within the phagolysosome compartment of mammalian macrophages. Although Leishmania depend on sugars as a major carbon source during infections, the nutrient composition of the phagolysosome remains poorly described. To determine the origin of the sugar carbon source in macrophage phagolysosomes, we have generated a N-acetylglucosamine acetyltransferase (GNAT) deficient Leishmania major mutant (∆gnat) that is auxotrophic for the amino sugar, N-acetylglucosamine (GlcNAc). This mutant was unable to grow or survive in ex vivo infected macrophages even when macrophages were cultivated in presence of exogenous GlcNAc. In contrast, the L. major ∆gnat mutant induced normal skin lesions in mice, suggesting that these parasites have access to GlcNAc in tissue macrophages. Intracellular growth of the mutant in ex vivo infected macrophages was restored by supplementation of the macrophage medium with hyaluronan, a GlcNAc-rich extracellular matrix glycosaminoglycan. Hyaluronan is present and constitutively turned-over in Leishmania-induced skin lesions and is efficiently internalized into Leishmania containing phagolysosomes. These findings suggest that the constitutive internalization and degradation of host glycosaminoglycans by macrophages provides Leishmania with essential carbon sources, creating a uniquely favorable niche for these parasites.
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Affiliation(s)
- Thomas Naderer
- The Department of Biochemistry and Molecular Biology and the Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Joanne Heng
- The Department of Biochemistry and Molecular Biology and the Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
| | - Eleanor C. Saunders
- The Department of Biochemistry and Molecular Biology and the Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
| | - Joachim Kloehn
- The Department of Biochemistry and Molecular Biology and the Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
| | - Thusitha W. Rupasinghe
- Metabolomics Australia, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
| | - Tracey J. Brown
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Malcolm J. McConville
- The Department of Biochemistry and Molecular Biology and the Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
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Previs SF, Herath K, Castro-Perez J, Mahsut A, Zhou H, McLaren DG, Shah V, Rohm RJ, Stout SJ, Zhong W, Wang SP, Johns DG, Hubbard BK, Cleary MA, Roddy TP. Effect of Error Propagation in Stable Isotope Tracer Studies: An Approach for Estimating Impact on Apparent Biochemical Flux. Methods Enzymol 2015; 561:331-58. [PMID: 26358910 DOI: 10.1016/bs.mie.2015.06.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Stable isotope tracers are widely used to quantify metabolic rates, and yet a limited number of studies have considered the impact of analytical error on estimates of flux. For example, when estimating the contribution of de novo lipogenesis, one typically measures a minimum of four isotope ratios, i.e., the precursor and product labeling pre- and posttracer administration. This seemingly simple problem has 1 correct solution and 80 erroneous outcomes. In this report, we outline a methodology for evaluating the effect of error propagation on apparent physiological endpoints. We demonstrate examples of how to evaluate the influence of analytical error in case studies concerning lipid and protein synthesis; we have focused on (2)H2O as a tracer and contrast different mass spectrometry platforms including GC-quadrupole-MS, GC-pyrolysis-IRMS, LC-quadrupole-MS, and high-resolution FT-ICR-MS. The method outlined herein can be used to determine how to minimize variations in the apparent biology by altering the dose and/or the type of tracer. Likewise, one can facilitate biological studies by estimating the reduction in the noise of an outcome that is expected for a given increase in the number of replicate injections.
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Affiliation(s)
| | | | | | - Ablatt Mahsut
- Merck Research Laboratories, Kenilworth, New Jersey, USA
| | - Haihong Zhou
- Merck Research Laboratories, Kenilworth, New Jersey, USA
| | | | - Vinit Shah
- Merck Research Laboratories, Kenilworth, New Jersey, USA
| | - Rory J Rohm
- Merck Research Laboratories, Kenilworth, New Jersey, USA
| | - Steven J Stout
- Merck Research Laboratories, Kenilworth, New Jersey, USA
| | - Wendy Zhong
- Merck Research Laboratories, Kenilworth, New Jersey, USA
| | | | | | | | | | - Thomas P Roddy
- Merck Research Laboratories, Kenilworth, New Jersey, USA
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Zhou H, Wang SP, Herath K, Kasumov T, Sadygov RG, Previs SF, Kelley DE. Tracer-based estimates of protein flux in cases of incomplete product renewal: evidence and implications of heterogeneity in collagen turnover. Am J Physiol Endocrinol Metab 2015; 309:E115-21. [PMID: 26015435 PMCID: PMC4596733 DOI: 10.1152/ajpendo.00435.2014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 05/04/2015] [Indexed: 11/22/2022]
Abstract
The synthesis of various molecules can be estimated by measuring the incorporation of a labeled precursor into a product of interest. Unfortunately, a central problem in many studies has been an inability to estimate the intracellular dilution of the precursor and therein correctly calculate the synthesis of the product; it is generally assumed that measuring the true product labeling is straightforward. We initiated a study to examine liver collagen synthesis and identified an apparent problem with assumptions regarding measurements of the product labeling. Since it is well known that collagen production is relatively slow, we relied on the use of [(2)H]H2O labeling (analogous to a primed infusion) and sampled animals over the course of 16 days. Although the water labeling (the precursor) remained stable and we observed the incorporation of labeled amino acids into collagen, the asymptotic protein labeling was considerably lower than what would be expected based on the precursor labeling. Although this observation is not necessarily surprising (i.e., one might expect that a substantial fraction of the collagen pool would appear "inert" or turn over at a very slow rate), its implications are of interest in certain areas. Herein, we discuss a novel situation in which tracers are used to quantify rates of flux under conditions where a product may not undergo complete replacement. We demonstrate how heterogeneity in the product pool can lead one to the wrong conclusions regarding estimates of flux, and we outline an approach that may help to minimize errors surrounding data interpretation.
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Affiliation(s)
- Haihong Zhou
- Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, New Jersey
| | - Sheng-Ping Wang
- Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, New Jersey
| | - Kithsiri Herath
- Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, New Jersey
| | - Takhar Kasumov
- Department of Gastroenterology and Hepatology, Cleveland Clinic, Cleveland, Ohio; and
| | - Rovshan G Sadygov
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas
| | - Stephen F Previs
- Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, New Jersey;
| | - David E Kelley
- Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, New Jersey
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35
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Walker DK, Thaden JJ, Deutz NEP. Application of gas chromatography-tandem mass spectrometry (GC/MS/MS) for the analysis of deuterium enrichment of water. JOURNAL OF MASS SPECTROMETRY : JMS 2015; 50:838-843. [PMID: 26169138 PMCID: PMC4503389 DOI: 10.1002/jms.3593] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 03/04/2015] [Accepted: 03/10/2015] [Indexed: 06/04/2023]
Abstract
Incorporation of deuterium from deuterium oxide ((2) H2 O) into biological components is a commonly used approach in metabolic studies. Determining the dilution of deuterium in the body water (BW) pool can be used to estimate body composition. We describe three sensitive GC/MS/MS methods to measure water enrichment in BW. Samples were reacted with NaOH and U-(13) C3 -acetone in an autosampler vial to promote deuterium exchange with U-(13) C3 -acetone hydrogens. Headspace injections were made of U-(13) C3 -acetone-saturated air onto a 30-m DB-1MS column in electron impact-mode. Subjects ingested 30 ml (2) H2 O, and plasma samples were collected. BW was determined by standard equation. Dual-energy X-ray absorptiometry scans were performed to calculate body mass, body volume and bone mineral content. A four-compartmental model was used to estimate body composition (fat and fat free mass). Full-scan experiments generated an m/z 45 peak and to a lesser extent an m/z 61 peak. Product fragment ions further monitored included 45 and 46 using selected ion monitoring (Method1), the 61 > 45 and 62 > 46 transition using multiple reaction monitoring (MRM; Method2) and the neutral loss, 62 > 45, transition (Method3). MRM methods were optimized for collision energy (CE) and collision-induced dissociation (CID) argon gas pressure with 6 eV CE and 1.5 mTorr CID gas being optimal. Method2 was used for final determination of (2) H2 O enrichment of subjects because of lower natural background. We have developed a sensitive method to determine (2) H2 O enrichment in BW to enable measurement of FM and FFM.
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Affiliation(s)
- Dillon K Walker
- Center for Translational Research in Aging and Longevity, Department of Health & Kinesiology, Texas A&M University, College Station, TX, 77843, USA
| | - John J Thaden
- Center for Translational Research in Aging and Longevity, Department of Health & Kinesiology, Texas A&M University, College Station, TX, 77843, USA
| | - Nicolaas E P Deutz
- Center for Translational Research in Aging and Longevity, Department of Health & Kinesiology, Texas A&M University, College Station, TX, 77843, USA
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36
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Kasumov T, Li L, Li M, Gulshan K, Kirwan JP, Liu X, Previs S, Willard B, Smith JD, McCullough A. Ceramide as a mediator of non-alcoholic Fatty liver disease and associated atherosclerosis. PLoS One 2015; 10:e0126910. [PMID: 25993337 PMCID: PMC4439060 DOI: 10.1371/journal.pone.0126910] [Citation(s) in RCA: 153] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 04/09/2015] [Indexed: 12/12/2022] Open
Abstract
Cardiovascular disease (CVD) is a serious comorbidity in nonalcoholic fatty liver disease (NAFLD). Since plasma ceramides are increased in NAFLD and sphingomyelin, a ceramide metabolite, is an independent risk factor for CVD, the role of ceramides in dyslipidemia was assessed using LDLR-/- mice, a diet-induced model of NAFLD and atherosclerosis. Mice were fed a standard or Western diet (WD), with or without myriocin, an inhibitor of ceramide synthesis. Hepatic and plasma ceramides were profiled and lipid and lipoprotein kinetics were quantified. Hepatic and intestinal expression of genes and proteins involved in insulin, lipid and lipoprotein metabolism were also determined. WD caused hepatic oxidative stress, inflammation, apoptosis, increased hepatic long-chain ceramides associated with apoptosis (C16 and C18) and decreased very-long-chain ceramide C24 involved in insulin signaling. The plasma ratio of ApoB/ApoA1 (proteins of VLDL/LDL and HDL) was increased 2-fold due to increased ApoB production. Myriocin reduced hepatic and plasma ceramides and sphingomyelin, and decreased atherosclerosis, hepatic steatosis, fibrosis, and apoptosis without any effect on oxidative stress. These changes were associated with decreased lipogenesis, ApoB production and increased HDL turnover. Thus, modulation of ceramide synthesis may lead to the development of novel strategies for the treatment of both NAFLD and its associated atherosclerosis.
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Affiliation(s)
- Takhar Kasumov
- Department of Gastroenterology& Hepatology, Cleveland Clinic, Cleveland, OH, United States of America
- * E-mail: (TK); (AM)
| | - Ling Li
- Department of Research Core Services, Cleveland Clinic, Cleveland, OH, United States of America
| | - Min Li
- Department of Pathobiology, Cleveland Clinic, Cleveland, OH, United States of America
| | - Kailash Gulshan
- Department of Cellular & Molecular Medicine, Cleveland Clinic, Cleveland, OH, United States of America
| | - John P. Kirwan
- Department of Pathobiology, Cleveland Clinic, Cleveland, OH, United States of America
| | - Xiuli Liu
- Department of Anatomic Pathology, Cleveland Clinic, Cleveland, OH, United States of America
| | - Stephen Previs
- Department of Nutrition & Medicine, Case Western Reserve University School of Medicine Cleveland Clinic, Cleveland, OH, United States of America
| | - Belinda Willard
- Department of Research Core Services, Cleveland Clinic, Cleveland, OH, United States of America
| | - Jonathan D. Smith
- Department of Cellular & Molecular Medicine, Cleveland Clinic, Cleveland, OH, United States of America
| | - Arthur McCullough
- Department of Gastroenterology& Hepatology, Cleveland Clinic, Cleveland, OH, United States of America
- Department of Pathobiology, Cleveland Clinic, Cleveland, OH, United States of America
- * E-mail: (TK); (AM)
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37
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Kloehn J, Saunders EC, O’Callaghan S, Dagley MJ, McConville MJ. Characterization of metabolically quiescent Leishmania parasites in murine lesions using heavy water labeling. PLoS Pathog 2015; 11:e1004683. [PMID: 25714830 PMCID: PMC4340956 DOI: 10.1371/journal.ppat.1004683] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 01/14/2015] [Indexed: 12/29/2022] Open
Abstract
Information on the growth rate and metabolism of microbial pathogens that cause long-term chronic infections is limited, reflecting the absence of suitable tools for measuring these parameters in vivo. Here, we have measured the replication and physiological state of Leishmania mexicana parasites in murine inflammatory lesions using 2H2O labeling. Infected BALB/c mice were labeled with 2H2O for up to 4 months, and the turnover of parasite DNA, RNA, protein and membrane lipids estimated from the rate of deuterium enrichment in constituent pentose sugars, amino acids, and fatty acids, respectively. We show that the replication rate of parasite stages in these tissues is very slow (doubling time of ~12 days), but remarkably constant throughout lesion development. Lesion parasites also exhibit markedly lower rates of RNA synthesis, protein turnover and membrane lipid synthesis than parasite stages isolated from ex vivo infected macrophages or cultured in vitro, suggesting that formation of lesions induces parasites to enter a semi-quiescent physiological state. Significantly, the determined parasite growth rate accounts for the overall increase in parasite burden indicating that parasite death and turnover of infected host cells in these lesions is minimal. We propose that the Leishmania response to lesion formation is an important adaptive strategy that minimizes macrophage activation, providing a permissive environment that supports progressive expansion of parasite burden. This labeling approach can be used to measure the dynamics of other host-microbe interactions in situ. Microbial pathogens can adapt to changing conditions in their hosts by switching between different growth and physiological states. However, current methods for measuring microbial physiology in vivo are limited, hampering detailed dissection of host-pathogen interactions. Here we have used heavy water labeling to measure the growth rate and physiological state of Leishmania parasites in murine lesions. Based on the rate of in situ labeling of parasite DNA, RNA, protein, and lipids, we show that the growth rate of intracellular parasite stages is very slow, and that these stages enter a semi-quiescent state characterized by very low rates of RNA, protein, and membrane turnover. These changes in parasite growth and physiology are more pronounced than in in vitro differentiated parasites, suggesting that they are induced in part by the lesion environment. Despite their slow growth, the parasite burden in these lesions progressively increases as a result of low rates of parasite death and host cell turnover. We propose that these changes in Leishmania growth and physiology contribute to the development of a relatively benign tissue environment that is permissive for long term parasite expansion. This approach is suitable for studying the dynamics of other host-pathogen systems.
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Affiliation(s)
- Joachim Kloehn
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
| | - Eleanor C. Saunders
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
| | - Sean O’Callaghan
- Metabolomics Australia, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
| | - Michael J. Dagley
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
| | - Malcolm J. McConville
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
- Metabolomics Australia, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
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Overexpression of sphingosine kinase 1 in liver reduces triglyceride content in mice fed a low but not high-fat diet. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:210-9. [PMID: 25490466 DOI: 10.1016/j.bbalip.2014.12.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 11/11/2014] [Accepted: 12/01/2014] [Indexed: 11/23/2022]
Abstract
Hepatic insulin resistance is a major risk factor for the development of type 2 diabetes and is associated with the accumulation of lipids, including diacylglycerol (DAG), triacylglycerols (TAG) and ceramide. There is evidence that enzymes involved in ceramide or sphingolipid metabolism may have a role in regulating concentrations of glycerolipids such as DAG and TAG. Here we have investigated the role of sphingosine kinase (SphK) in regulating hepatic lipid levels. We show that mice on a high-fat high-sucrose diet (HFHS) displayed glucose intolerance, elevated liver TAG and DAG, and a reduction in total hepatic SphK activity. Reduced SphK activity correlated with downregulation of SphK1, but not SphK2 expression, and was not associated with altered ceramide levels. The role of SphK1 was further investigated by overexpressing this isoform in the liver of mice in vivo. On a low-fat diet (LFD) mice overexpressing liver SphK1, displayed reduced hepatic TAG synthesis and total TAG levels, but with no change to DAG or ceramide. These mice also exhibited no change in gluconeogenesis, glycogenolysis or glucose tolerance. Similarly, overexpression of SphK1 had no effect on the pattern of endogenous glucose production determined during a glucose tolerance test. Under HFHS conditions, normalization of liver SphK activity to levels observed in LFD controls did not alter hepatic TAG concentrations. Furthermore, DAG, ceramide and glucose tolerance were also unaffected. In conclusion, our data suggest that SphK1 plays an important role in regulating TAG metabolism under LFD conditions.
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Camus G, Schweiger M, Herker E, Harris C, Kondratowicz AS, Tsou CL, Farese RV, Herath K, Previs SF, Roddy TP, Pinto S, Zechner R, Ott M. The hepatitis C virus core protein inhibits adipose triglyceride lipase (ATGL)-mediated lipid mobilization and enhances the ATGL interaction with comparative gene identification 58 (CGI-58) and lipid droplets. J Biol Chem 2014; 289:35770-80. [PMID: 25381252 DOI: 10.1074/jbc.m114.587816] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Liver steatosis is a common health problem associated with hepatitis C virus (HCV) and an important risk factor for the development of liver fibrosis and cancer. Steatosis is caused by triglycerides (TG) accumulating in lipid droplets (LDs), cellular organelles composed of neutral lipids surrounded by a monolayer of phospholipids. The HCV nucleocapsid core localizes to the surface of LDs and induces steatosis in cultured cells and mouse livers by decreasing intracellular TG degradation (lipolysis). Here we report that core at the surface of LDs interferes with the activity of adipose triglyceride lipase (ATGL), the key lipolytic enzyme in the first step of TG breakdown. Expressing core in livers or mouse embryonic fibroblasts of ATGL(-/-) mice no longer decreases TG degradation as observed in LDs from wild-type mice, supporting the model that core reduces lipolysis by engaging ATGL. Core must localize at LDs to inhibit lipolysis, as ex vivo TG hydrolysis is impaired in purified LDs coated with core but not when free core is added to LDs. Coimmunoprecipitation experiments revealed that core does not directly interact with the ATGL complex but, unexpectedly, increased the interaction between ATGL and its activator CGI-58 as well as the recruitment of both proteins to LDs. These data link the anti-lipolytic activity of the HCV core protein with altered ATGL binding to CGI-58 and the enhanced association of both proteins with LDs.
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Affiliation(s)
- Gregory Camus
- From the Gladstone Institute of Virology and Immunology, San Francisco, California 94158
| | - Martina Schweiger
- From the Gladstone Institute of Virology and Immunology, San Francisco, California 94158, Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Eva Herker
- From the Gladstone Institute of Virology and Immunology, San Francisco, California 94158, UCSF Liver Center, University of California, San Francisco, California 94158, Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, 20251 Hamburg, Germany
| | - Charles Harris
- UCSF Liver Center, University of California, San Francisco, California 94158, Gladstone Institute of Cardiovascular Disease, San Francisco, California 94158, Department of Medicine, University of California, San Francisco, California 94158, Division of Endocrinology Metabolism and Lipid Research, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Andrew S Kondratowicz
- From the Gladstone Institute of Virology and Immunology, San Francisco, California 94158
| | - Chia-Lin Tsou
- From the Gladstone Institute of Virology and Immunology, San Francisco, California 94158
| | - Robert V Farese
- UCSF Liver Center, University of California, San Francisco, California 94158, Gladstone Institute of Cardiovascular Disease, San Francisco, California 94158, Department of Medicine, University of California, San Francisco, California 94158, Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158, and
| | - Kithsiri Herath
- Merck Research Laboratories, Merck and Co., Inc., Kenilworth, New Jersey 07065
| | - Stephen F Previs
- Merck Research Laboratories, Merck and Co., Inc., Kenilworth, New Jersey 07065
| | - Thomas P Roddy
- Merck Research Laboratories, Merck and Co., Inc., Kenilworth, New Jersey 07065
| | - Shirly Pinto
- Merck Research Laboratories, Merck and Co., Inc., Kenilworth, New Jersey 07065
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Melanie Ott
- From the Gladstone Institute of Virology and Immunology, San Francisco, California 94158, UCSF Liver Center, University of California, San Francisco, California 94158, Department of Medicine, University of California, San Francisco, California 94158,
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Wang SP, Daniels E, Chen Y, Castro-Perez J, Zhou H, Akinsanya KO, Previs SF, Roddy TP, Johns DG. In vivo effects of anacetrapib on preβ HDL: improvement in HDL remodeling without effects on cholesterol absorption. J Lipid Res 2013; 54:2858-65. [PMID: 23898048 DOI: 10.1194/jlr.m041541] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Cholesteryl ester transfer protein (CETP) transfers cholesteryl ester and triglyceride between HDL and apoB-containing lipoproteins. Anacetrapib (ANA), a reversible inhibitor of CETP, raises HDL cholesterol and lowers LDL cholesterol in dyslipidemic patients. We previously demonstrated that ANA increases macrophage-to-feces reverse cholesterol transport and fecal cholesterol excretion in hamsters, and increased preβ HDL-dependent cholesterol efflux via ABCA1 in vitro. However, the effects of ANA on in vivo preβ HDL have not been characterized. In vitro, ANA inhibited the formation of preβ, however in ANA-treated dyslipidemic hamsters, preβ HDL levels (measured by two-dimensional gel electrophoresis) were increased, in contrast to in vitro findings. Because changes in plasma preβ HDL have been proposed to potentially affect markers of cholesterol absorption with other CETP inhibitors, a dual stable isotope method was used to directly measure cholesterol absorption in hamsters. ANA treatment of hamsters (on either dyslipidemic or normal diet) had no effect on cholesterol absorption, while dalcetrapib-treated hamsters displayed an increase in cholesterol absorption. Taken together, these data support the notion that ANA promotes preβ HDL functionality in vivo, with no effects on cholesterol absorption.
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Affiliation(s)
- Sheng-Ping Wang
- Department of Atherosclerosis, Merck Research Laboratories, Rahway, NJ 07065
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41
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Kasumov T, Dabkowski ER, Shekar KC, Li L, Ribeiro RF, Walsh K, Previs SF, Sadygov RG, Willard B, Stanley WC. Assessment of cardiac proteome dynamics with heavy water: slower protein synthesis rates in interfibrillar than subsarcolemmal mitochondria. Am J Physiol Heart Circ Physiol 2013; 304:H1201-14. [PMID: 23457012 DOI: 10.1152/ajpheart.00933.2012] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Traditional proteomics provides static assessment of protein content, but not synthetic rates. Recently, proteome dynamics with heavy water ((2)H2O) was introduced, where (2)H labels amino acids that are incorporated into proteins, and the synthesis rate of individual proteins is calculated using mass isotopomer distribution analysis. We refine this approach with a novel algorithm and rigorous selection criteria that improve the accuracy and precision of the calculation of synthesis rates and use it to measure protein kinetics in spatially distinct cardiac mitochondrial subpopulations. Subsarcolemmal mitochondria (SSM) and interfibrillar mitochondria (IFM) were isolated from adult rats, which were given (2)H2O in the drinking water for up to 60 days. Plasma (2)H2O and myocardial (2)H-enrichment of amino acids were stable throughout the experimental protocol. Multiple tryptic peptides were identified from 28 proteins in both SSM and IFM and showed a time-dependent increase in heavy mass isotopomers that was consistent within a given protein. Mitochondrial protein synthesis was relatively slow (average half-life of 30 days, 2.4% per day). Although the synthesis rates for individual proteins were correlated between IFM and SSM (R(2) = 0.84; P < 0.0001), values in IFM were 15% less than SSM (P < 0.001). In conclusion, administration of (2)H2O results in stable enrichment of the cardiac precursor amino acid pool, with the use of refined analytical and computational methods coupled with cell fractionation one can measure synthesis rates for cardiac proteins in subcellular compartments in vivo, and protein synthesis is slower in mitochondria located among the myofibrils than in the subsarcolemmal region.
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Affiliation(s)
- Takhar Kasumov
- Department of Gastroenterology and Hepatology, Cleveland Clinic, Cleveland, Ohio 44195, USA.
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Li L, Willard B, Rachdaoui N, Kirwan JP, Sadygov RG, Stanley WC, Previs S, McCullough AJ, Kasumov T. Plasma proteome dynamics: analysis of lipoproteins and acute phase response proteins with 2H2O metabolic labeling. Mol Cell Proteomics 2012; 11:M111.014209. [PMID: 22393261 PMCID: PMC3394944 DOI: 10.1074/mcp.m111.014209] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 02/16/2012] [Indexed: 11/06/2022] Open
Abstract
Understanding the pathologies related to the regulation of protein metabolism requires methods for studying the kinetics of individual proteins. We developed a (2)H(2)O metabolic labeling technique and software for protein kinetic studies in free living organisms. This approach for proteome dynamic studies requires the measurement of total body water enrichments by GC-MS, isotopic distribution of the tryptic peptide by LC-MS/MS, and estimation of the asymptotical number of deuterium incorporated into a peptide by software. We applied this technique to measure the synthesis rates of several plasma lipoproteins and acute phase response proteins in rats. Samples were collected at different time points, and proteins were separated by a gradient gel electrophoresis. (2)H labeling of tryptic peptides was analyzed by ion trap tandem mass spectrometry (LTQ MS/MS) for measurement of the fractional synthesis rates of plasma proteins. The high sensitivity of LTQ MS in zoom scan mode in combination with (2)H label amplification in proteolytic peptides allows detection of the changes in plasma protein synthesis related to animal nutritional status. Our results demonstrate that fasting has divergent effects on the rate of synthesis of plasma proteins, increasing synthesis of ApoB 100 but decreasing formation of albumin and fibrinogen. We conclude that this technique can effectively measure the synthesis of plasma proteins and can be used to study the regulation of protein homeostasis under physiological and pathological conditions.
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Affiliation(s)
- Ling Li
- From the Departments of ‡Research Core Services and
| | | | - Nadia Rachdaoui
- §School of Medicine, Case Western Reserve University, Cleveland, Ohio 44195
| | - John P. Kirwan
- ¶Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, Ohio 44195
| | - Rovshan G. Sadygov
- the ‖Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Texas 77555, and
| | - William C. Stanley
- the **Division of Cardiology, Department of Medicine, University of Maryland Medical Center, Baltimore, Maryland 21201-1595
| | - Stephen Previs
- §School of Medicine, Case Western Reserve University, Cleveland, Ohio 44195
| | | | - Takhar Kasumov
- ¶Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, Ohio 44195
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Zhou H, Li W, Wang SP, Mendoza V, Rosa R, Hubert J, Herath K, McLaughlin T, Rohm RJ, Lassman ME, Wong KK, Johns DG, Previs SF, Hubbard BK, Roddy TP. Quantifying apoprotein synthesis in rodents: coupling LC-MS/MS analyses with the administration of labeled water. J Lipid Res 2012; 53:1223-31. [PMID: 22389331 DOI: 10.1194/jlr.d021295] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Stable isotope tracer studies of apoprotein flux in rodent models present difficulties as they require working with small volumes of plasma. We demonstrate the ability to measure apoprotein flux by administering either (2)H- or (18)O-labeled water to mice and then subjecting samples to LC-MS/MS analyses; we were able to simultaneously determine the labeling of several proteolytic peptides representing multiple apoproteins. Consistent with relative differences reported in the literature regarding apoprotein flux in humans, we found that the fractional synthetic rate of apoB is greater than apoA1 in mice. In addition, the method is suitable for quantifying acute changes in protein flux: we observed a stimulation of apoB production in mice following an intravenous injection of Intralipid and a decrease in apoB production in mice treated with an inhibitor of microsomal triglyceride transfer protein. In summary, we demonstrate a high-throughput method for studying apoprotein kinetics in rodent models. Although notable differences exist between lipoprotein profiles that are observed in rodents and humans, we expect that the method reported here has merit in studies of dyslipidemia as i) rodent models can be used to probe target engagement in cases where one aims to modulate apoprotein production and ii) the approach should be adaptable to studies in humans.
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Affiliation(s)
- Haihong Zhou
- Atherosclerosis, Merck Research Laboratories, Rahway, NJ 07065, USA
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Kamphorst JJ, Fan J, Lu W, White E, Rabinowitz JD. Liquid chromatography-high resolution mass spectrometry analysis of fatty acid metabolism. Anal Chem 2011; 83:9114-22. [PMID: 22004349 DOI: 10.1021/ac202220b] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We present a liquid chromatography/mass spectrometry (LC/MS) method for long-chain and very-long-chain fatty acid analysis and its application to (13)C-tracer studies of fatty acid metabolism. Fatty acids containing 14 to 36 carbon atoms are separated by C(8) reversed-phase chromatography using a water-methanol gradient with tributylamine as ion pairing agent, ionized by electrospray and analyzed by a stand-alone orbitrap mass spectrometer. The median limit of detection is 5 ng/mL with a linear dynamic range of 100-fold. Ratios of unlabeled to (13)C-labeled species are quantitated precisely and accurately (average relative standard deviation 3.2% and deviation from expectation 2.3%). In samples consisting of fatty acids saponified from cultured mammalian cells, 45 species are quantified, with average intraday relative standard deviations for independent biological replicates of 11%. The method enables quantitation of molecular ion peaks for all labeled forms of each fatty acid. Different degrees of (13)C-labeling from glucose and glutamine correspond to fatty acid uptake from media, de novo synthesis, and elongation. To exemplify the utility of the method, we examined isogenic cell lines with and without activated Ras oncogene expression. Ras increases the abundance and alters the labeling patterns of saturated and monounsaturated very-long-chain fatty acids, with the observed pattern consistent with Ras leading to enhanced activity of ELOVL4 or an enzyme with similar catalytic activity. This LC/MS method and associated isotope tracer techniques should be broadly applicable to investigating fatty acid metabolism.
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Affiliation(s)
- Jurre J Kamphorst
- Lewis-Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
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45
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Herath K, Bhat G, Miller PL, Wang SP, Kulick A, Andrews-Kelly G, Johnson C, Rohm RJ, Lassman ME, Previs SF, Johns DG, Hubbard BK, Roddy TP. Equilibration of (2)H labeling between body water and free amino acids: enabling studies of proteome synthesis. Anal Biochem 2011; 415:197-9. [PMID: 21596013 DOI: 10.1016/j.ab.2011.04.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2010] [Revised: 04/02/2011] [Accepted: 04/19/2011] [Indexed: 11/19/2022]
Abstract
Protein synthesis can be estimated by measuring the incorporation of a labeled amino acid into a proteolytic peptide. Although prelabeled amino acids are typically administered, recent studies have tested (2)H(2)O; the assumption is that there is rapid equilibration of (2)H (in body water) with the carbon-bound hydrogens of amino acids before those amino acids are incorporated into a protein(s). We have determined the temporal changes in (2)H labeling of body water and amino acids which should build confidence in (2)H(2)O-based studies of protein synthesis when one aims to measure the (2)H labeling of proteolytic peptides.
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Affiliation(s)
- Kithsiri Herath
- Atherosclerosis, Merck Research Laboratories, Rahway, NJ 07065, USA
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46
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Previs SF, Mahsut A, Kulick A, Dunn K, Andrews-Kelly G, Johnson C, Bhat G, Herath K, Miller PL, Wang SP, Azer K, Xu J, Johns DG, Hubbard BK, Roddy TP. Quantifying cholesterol synthesis in vivo using (2)H(2)O: enabling back-to-back studies in the same subject. J Lipid Res 2011; 52:1420-8. [PMID: 21498887 DOI: 10.1194/jlr.d014993] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The advantages of using (2)H(2)O to quantify cholesterol synthesis include i) homogeneous precursor labeling, ii) incorporation of (2)H via multiple pathways, and iii) the ability to perform long-term studies in free-living subjects. However, there are two concerns. First, the t(1/2) of tracer in body water presents a challenge when there is a need to acutely replicate measurements in the same subject. Second, assumptions are made regarding the number of hydrogens (n) that are incorporated during de novo synthesis. Our primary objective was to determine whether a step-based approach could be used to repeatedly study cholesterol synthesis a subject. We observed comparable changes in the (2)H-labeling of plasma water and total plasma cholesterol in African-Green monkeys that received five oral doses of (2)H(2)O, each dose separated by one week. Similar rates of cholesterol synthesis were estimated when comparing data in the group over the different weeks, but better reproducibility was observed when comparing replicate determinations of cholesterol synthesis in the same nonhuman primate during the respective dosing periods. Our secondary objective was to determine whether n depends on nutritional status in vivo; we observed n of ∼25 and ∼27 in mice fed a high-carbohydrate (HC) versus carbohydrate-free (CF) diet, respectively. We conclude that it is possible to acutely repeat studies of cholesterol synthesis using (2)H(2)O and that n is relatively constant.
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Kasumov T, Ilchenko S, Li L, Rachdaoui N, Sadygov RG, Willard B, McCullough AJ, Previs S. Measuring protein synthesis using metabolic ²H labeling, high-resolution mass spectrometry, and an algorithm. Anal Biochem 2011; 412:47-55. [PMID: 21256107 DOI: 10.1016/j.ab.2011.01.021] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 01/14/2011] [Indexed: 10/18/2022]
Abstract
We recently developed a method for estimating protein dynamics in vivo with heavy water ((2)H(2)O) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) [16], and we confirmed that (2)H labeling of many hepatic free amino acids rapidly equilibrated with body water. Although this is a reliable method, it required modest sample purification and necessitated the determination of tissue-specific amino acid labeling. Another approach for quantifying protein kinetics is to measure the (2)H enrichments of body water (precursor) and protein-bound amino acid or proteolytic peptide (product) and to estimate how many copies of deuterium are incorporated into a product. In the current study, we used nanospray linear trap Fourier transform ion cyclotron resonance mass spectrometry (LTQ FT-ICR MS) to simultaneously measure the isotopic enrichment of peptides and protein-bound amino acids. A mathematical algorithm was developed to aid the data processing. The most notable improvement centers on the fact that the precursor/product labeling ratio can be obtained by measuring the labeling of water and a protein (or peptide) of interest, thereby minimizing the need to measure the amino acid labeling. As a proof of principle, we demonstrate that this approach can detect the effect of nutritional status on albumin synthesis in rats given (2)H(2)O.
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Affiliation(s)
- Takhar Kasumov
- Department of Gastroenterology, Cleveland Clinic, Cleveland, OH 44195, USA.
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48
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Mahsut A, Wang SP, McLaren DG, Bhat G, Herath K, Miller PL, Hubbard BK, Johns DG, Previs SF, Roddy TP. Headspace analyses of 2H labeling of acetone: Enabling studies of fatty acid oxidation in vivo. Anal Biochem 2011; 408:351-3. [DOI: 10.1016/j.ab.2010.09.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 09/10/2010] [Accepted: 09/10/2010] [Indexed: 11/24/2022]
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Castro-Perez J, Previs SF, McLaren DG, Shah V, Herath K, Bhat G, Johns DG, Wang SP, Mitnaul L, Jensen K, Vreeken R, Hankemeier T, Roddy TP, Hubbard BK. In vivo D2O labeling to quantify static and dynamic changes in cholesterol and cholesterol esters by high resolution LC/MS. J Lipid Res 2010; 52:159-69. [PMID: 20884843 DOI: 10.1194/jlr.d009787] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
High resolution LC/MS-MS and LC/APPI-MS methods have been established for the quantitation of flux in the turnover of cholesterol and cholesterol ester. Attention was directed toward quantifying the monoisotopic mass (M0) and that of the singly deuterated labeled (M+1) isotope. A good degree of isotopic dynamic range has been achieved by LC/MS-MS ranging from 3-4 orders of magnitude. Correlation between the linearity of GC/MS and LC atmospheric pressure photoionization (APPI)-MS are complimentary (r² = 0.9409). To prove the viability of this particular approach, male C57Bl/6 mice on either a high carbohydrate (HC) or a high fat (HF) diet were treated with ²H₂O for 96 h. Gene expression analysis showed an increase in the activity of stearoyl-CoA desaturase (Scd1) in the HC diet up to 69-fold (P < 0.0008) compared with the HF diet. This result was supported by the quantitative flux measurement of the isotopic incorporation of ²H into the respective cholesterol and cholesterol ester (CE) pools. We concluded that it is possible to readily obtain static and dynamic measurement of cholesterol and CEs in vivo by coupling novel LC/MS methods with stable isotope-based protocols.
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Affiliation(s)
- Jose Castro-Perez
- Atherosclerosis Exploratory Biomarkers Group, Merck & Co., Inc., Rahway, NJ, USA.
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