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Wang G, Laranjeiro R, LeValley S, Van Raamsdonk JM, Driscoll M. The glyoxylate shunt protein ICL-1 protects from mitochondrial superoxide stress through activation of the mitochondrial unfolded protein response. Free Radic Biol Med 2023; 208:771-779. [PMID: 37758122 DOI: 10.1016/j.freeradbiomed.2023.09.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 09/05/2023] [Accepted: 09/24/2023] [Indexed: 10/03/2023]
Abstract
Disrupting mitochondrial superoxide dismutase (SOD) causes neonatal lethality in mice and death of flies within 24 h after eclosion. Deletion of mitochondrial sod genes in C. elegans impairs fertility as well, but surprisingly is not detrimental to survival of progeny generated. The comparison of metabolic pathways among mouse, flies and nematodes reveals that mice and flies lack the glyoxylate shunt, a shortcut that bypasses part of the tricarboxylic acid (TCA) cycle. Here we show that ICL-1, the sole protein that catalyzes the glyoxylate shunt, is critical for protection against embryonic lethality resulting from elevated levels of mitochondrial superoxide. In exploring the mechanism by which ICL-1 protects against ROS-mediated embryonic lethality, we find that ICL-1 is required for the efficient activation of mitochondrial unfolded protein response (UPRmt) and that ATFS-1, a key UPRmt transcription factor and an activator of icl-1 gene expression, is essential to limit embryonic/neonatal lethality in animals lacking mitochondrial SOD. In sum, we identify a biochemical pathway that highlights a molecular strategy for combating toxic mitochondrial superoxide consequences in cells.
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Affiliation(s)
- Guoqiang Wang
- Department of Molecular Biology and Biochemistry, School of Arts and Sciences, Rutgers, the State University of New Jersey, Piscataway, NJ, USA
| | - Ricardo Laranjeiro
- Department of Molecular Biology and Biochemistry, School of Arts and Sciences, Rutgers, the State University of New Jersey, Piscataway, NJ, USA
| | - Stephanie LeValley
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA
| | - Jeremy M Van Raamsdonk
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada; Metabolic Disorders and Complications Program, and Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada; Division of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Monica Driscoll
- Department of Molecular Biology and Biochemistry, School of Arts and Sciences, Rutgers, the State University of New Jersey, Piscataway, NJ, USA.
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Morris EM, Noland RD, Ponte ME, Montonye ML, Christianson JA, Stanford JA, Miles JM, Hayes MR, Thyfault JP. Reduced Liver-Specific PGC1a Increases Susceptibility for Short-Term Diet-Induced Weight Gain in Male Mice. Nutrients 2021; 13:2596. [PMID: 34444756 PMCID: PMC8400659 DOI: 10.3390/nu13082596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/21/2021] [Accepted: 07/24/2021] [Indexed: 11/18/2022] Open
Abstract
The central integration of peripheral neural signals is one mechanism by which systemic energy homeostasis is regulated. Previously, increased acute food intake following the chemical reduction of hepatic fatty acid oxidation and ATP levels was prevented by common hepatic branch vagotomy (HBV). However, possible offsite actions of the chemical compounds confound the precise role of liver energy metabolism. Herein, we used a hepatocyte PGC1a heterozygous (LPGC1a) mouse model, with associated reductions in mitochondrial fatty acid oxidation and respiratory capacity, to assess the role of liver energy metabolism in systemic energy homeostasis. LPGC1a male, but not female, mice had a 70% greater high-fat/high-sucrose (HFHS) diet-induced weight gain compared to wildtype (WT) mice (p < 0.05). The greater weight gain was associated with altered feeding behavior and lower activity energy expenditure during the HFHS diet in LPGC1a males. WT and LPGC1a mice underwent sham surgery or HBV to assess whether vagal signaling was involved in the HFHS-induced weight gain of male LPGC1a mice. HBV increased HFHS-induced weight gain (85%, p < 0.05) in male WT mice, but not LPGC1a mice. These data demonstrate a sex-specific role of reduced liver energy metabolism in acute diet-induced weight gain, and the need for a more nuanced assessment of the role of vagal signaling in short-term diet-induced weight gain.
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Affiliation(s)
- E. Matthew Morris
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA; (R.D.N.); (M.E.P.); (J.A.S.); (J.P.T.)
- Center for Children’s Healthy Lifestyle and Nutrition, Children’s Mercy Hospital, Kansas City, MO 64108, USA
| | - Roberto D. Noland
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA; (R.D.N.); (M.E.P.); (J.A.S.); (J.P.T.)
| | - Michael E. Ponte
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA; (R.D.N.); (M.E.P.); (J.A.S.); (J.P.T.)
| | - Michelle L. Montonye
- Department of Nutrition & Exercise Physiology, University of Missouri, Columbia, MO 65211, USA;
| | - Julie A. Christianson
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA;
| | - John A. Stanford
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA; (R.D.N.); (M.E.P.); (J.A.S.); (J.P.T.)
| | - John M. Miles
- Department of Internal Medicine—Division of Endocrinology and Metabolism, University of Kansas Medical Center, Kansas City, KS 66160, USA;
| | - Matthew R. Hayes
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA;
| | - John P. Thyfault
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA; (R.D.N.); (M.E.P.); (J.A.S.); (J.P.T.)
- Center for Children’s Healthy Lifestyle and Nutrition, Children’s Mercy Hospital, Kansas City, MO 64108, USA
- Department of Internal Medicine—Division of Endocrinology and Metabolism, University of Kansas Medical Center, Kansas City, KS 66160, USA;
- Kansas City VA Medical Center-Research Service, Kansas City, MO 64128, USA
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3
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Link JC, Wiese CB, Chen X, Avetisyan R, Ronquillo E, Ma F, Guo X, Yao J, Allison M, Chen YDI, Rotter JI, El -Sayed Moustafa JS, Small KS, Iwase S, Pellegrini M, Vergnes L, Arnold AP, Reue K. X chromosome dosage of histone demethylase KDM5C determines sex differences in adiposity. J Clin Invest 2020; 130:5688-5702. [PMID: 32701509 PMCID: PMC7598065 DOI: 10.1172/jci140223] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/16/2020] [Indexed: 12/29/2022] Open
Abstract
Males and females differ in body composition and fat distribution. Using a mouse model that segregates gonadal sex (ovaries and testes) from chromosomal sex (XX and XY), we showed that XX chromosome complement in combination with a high-fat diet led to enhanced weight gain in the presence of male or female gonads. We identified the genomic dosage of Kdm5c, an X chromosome gene that escapes X chromosome inactivation, as a determinant of the X chromosome effect on adiposity. Modulating Kdm5c gene dosage in XX female mice to levels that are normally present in males resulted in reduced body weight, fat content, and food intake to a degree similar to that seen with altering the entire X chromosome dosage. In cultured preadipocytes, the levels of KDM5C histone demethylase influenced chromatin accessibility (ATAC-Seq), gene expression (RNA-Seq), and adipocyte differentiation. Both in vitro and in vivo, Kdm5c dosage influenced gene expression involved in extracellular matrix remodeling, which is critical for adipocyte differentiation and adipose tissue expansion. In humans, adipose tissue KDM5C mRNA levels and KDM5C genetic variants were associated with body mass. These studies demonstrate that the sex-dependent dosage of Kdm5c contributes to male/female differences in adipocyte biology and highlight X-escape genes as a critical component of female physiology.
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Affiliation(s)
| | | | - Xuqi Chen
- Integrative Biology and Physiology, and
| | | | | | - Feiyang Ma
- Molecular, Cellular and Developmental Biology, UCLA, Los Angeles, California, USA
| | - Xiuqing Guo
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Jie Yao
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Matthew Allison
- Division of Preventive Medicine, School of Medicine, UCSD, San Diego, California, USA
| | - Yii-Der Ida Chen
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Jerome I. Rotter
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | | | - Kerrin S. Small
- Department of Twin Research and Genetic Epidemiology, King’s College London, London, United Kingdom
| | - Shigeki Iwase
- Human Genetics, Medical School, University of Michigan, Ann Arbor, Michigan, USA
| | - Matteo Pellegrini
- Molecular, Cellular and Developmental Biology, UCLA, Los Angeles, California, USA
| | | | | | - Karen Reue
- Molecular Biology Institute
- Human Genetics, David Geffen School of Medicine
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4
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Karimi M, Petkova V, Asara JM, Griffin MJ, Sellke FW, Bishop AR, Alexandrov BS, Usheva A. Metabolomics and the pig model reveal aberrant cardiac energy metabolism in metabolic syndrome. Sci Rep 2020; 10:3483. [PMID: 32103083 PMCID: PMC7044421 DOI: 10.1038/s41598-020-60387-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 02/03/2020] [Indexed: 11/09/2022] Open
Abstract
Although metabolic syndrome (MS) is a significant risk of cardiovascular disease (CVD), the cardiac response (MR) to MS remains unclear due to traditional MS models' narrow scope around a limited number of cell-cycle regulation biomarkers and drawbacks of limited human tissue samples. To date, we developed the most comprehensive platform studying MR to MS in a pig model tightly related to human MS criteria. By incorporating comparative metabolomic, transcriptomic, functional analyses, and unsupervised machine learning (UML), we can discover unknown metabolic pathways connections and links on numerous biomarkers across the MS-associated issues in the heart. For the first time, we show severely diminished availability of glycolytic and citric acid cycle (CAC) pathways metabolites, altered expression, GlcNAcylation, and activity of involved enzymes. A notable exception, however, is the excessive succinate accumulation despite reduced succinate dehydrogenase complex iron-sulfur subunit b (SDHB) expression and decreased content of precursor metabolites. Finally, the expression of metabolites and enzymes from the GABA-glutamate, GABA-putrescine, and the glyoxylate pathways significantly increase, suggesting an alternative cardiac means to replenish succinate and malate in MS. Our platform discovers potential therapeutic targets for MS-associated CVD within pathways that were previously unknown to corelate with the disease.
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Affiliation(s)
- Maryam Karimi
- Division of Cardiothoracic Surgery, Department of Surgery, The Warren Alpert Medical School, Brown University, Providence, RI, 02903, United States
| | - Victoria Petkova
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02115, United States
| | - John M Asara
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02115, United States
| | - Michael J Griffin
- Sam Houston State University, College of Osteopathic Medicine, Huntsville, TX, 77320, United States
| | - Frank W Sellke
- Division of Cardiothoracic Surgery, Department of Surgery, The Warren Alpert Medical School, Brown University, Providence, RI, 02903, United States
| | - Alan R Bishop
- Los Alamos National Laboratory, Los Alamos, NM, 87545, United States
| | | | - Anny Usheva
- Division of Cardiothoracic Surgery, Department of Surgery, The Warren Alpert Medical School, Brown University, Providence, RI, 02903, United States.
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5
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Abstract
2017 marks the 60th anniversary of Krebs’ seminal paper on the glyoxylate shunt (and coincidentally, also the 80th anniversary of his discovery of the citric acid cycle). Sixty years on, we have witnessed substantial developments in our understanding of how flux is partitioned between the glyoxylate shunt and the oxidative decarboxylation steps of the citric acid cycle. The last decade has shown us that the beautifully elegant textbook mechanism that regulates carbon flux through the shunt in E. coli is an oversimplification of the situation in many other bacteria. The aim of this review is to assess how this new knowledge is impacting our understanding of flux control at the TCA cycle/glyoxylate shunt branch point in a wider range of genera, and to summarize recent findings implicating a role for the glyoxylate shunt in cellular functions other than metabolism.
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Affiliation(s)
- Stephen K. Dolan
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom;,
| | - Martin Welch
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom;,
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6
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Pace RM, Prince AL, Ma J, Belfort BDW, Harvey AS, Hu M, Baquero K, Blundell P, Takahashi D, Dean T, Kievit P, Sullivan EL, Friedman JE, Grove K, Aagaard KM. Modulations in the offspring gut microbiome are refractory to postnatal synbiotic supplementation among juvenile primates. BMC Microbiol 2018; 18:28. [PMID: 29621980 PMCID: PMC5887201 DOI: 10.1186/s12866-018-1169-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 03/19/2018] [Indexed: 02/07/2023] Open
Abstract
Background We and others have previously shown that alterations in the mammalian gut microbiome are associated with diet, notably early life exposure to a maternal high fat diet (HFD). Here, we aimed to further these studies by examining alterations in the gut microbiome of juvenile Japanese macaques (Macaca fuscata) that were exposed to a maternal HFD, weaned onto a control diet, and later supplemented with a synbiotic comprised of psyllium seed and Enterococcus and Lactobacillus species. Results Eighteen month old offspring (n = 7) of 36% HFD fed dams were fed a control (14% fat) diet post weaning, then were synbiotic supplemented for 75 days and longitudinal stool and serum samples were obtained. All stool samples were subjected to 16S rRNA metagenomic sequencing, and microbiome profiles and serum lipids and triglycerides were compared to untreated, healthy age matched and diet matched controls (n = 7). Overall, 16S-based metagenomic analysis revealed that supplementation exerted minimal alterations to the gut microbiome including transient increased abundance of Lactobacillus species and decreased abundance of few bacterial genera, including Faecalibacterium and Anaerovibrio. However, serum lipid analysis revealed significant decreases in triglycerides, cholesterol, and LDL (p < 0.05). Nevertheless, supplemented juveniles challenged 4 months later were not protected from HFD-induced gut dysbiosis. Conclusions Synbiotic supplementation is temporally associated with alterations in the gut microbiome and host lipid profiles of juvenile Japanese macaques that were previously exposed to a maternal HFD. Despite these presumptive temporal benefits, a protective effect against later HFD-challenge gut dysbiosis was not observed. Electronic supplementary material The online version of this article (10.1186/s12866-018-1169-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ryan M Pace
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Amanda L Prince
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Jun Ma
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Benjamin D W Belfort
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Alexia S Harvey
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Min Hu
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Karalee Baquero
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97239, USA
| | - Peter Blundell
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97239, USA
| | - Diana Takahashi
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97239, USA
| | - Tyler Dean
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97239, USA
| | - Paul Kievit
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97239, USA
| | - Elinor L Sullivan
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97239, USA.,Biology Department, University of Portland, Portland, OR, 97203, USA
| | - Jacob E Friedman
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Kevin Grove
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97239, USA
| | - Kjersti M Aagaard
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Molecular and Cell Biology, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA. .,Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97239, USA.
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7
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Dezfuli G, Gillis RA, Tatge JE, Duncan KR, Dretchen KL, Jackson PG, Verbalis JG, Sahibzada N. Subdiaphragmatic Vagotomy With Pyloroplasty Ameliorates the Obesity Caused by Genetic Deletion of the Melanocortin 4 Receptor in the Mouse. Front Neurosci 2018; 12:104. [PMID: 29545738 PMCID: PMC5838008 DOI: 10.3389/fnins.2018.00104] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 02/12/2018] [Indexed: 12/22/2022] Open
Abstract
Background/Objectives: We tested the hypothesis that abolishing vagal nerve activity will reverse the obesity phenotype of melanocortin 4 receptor knockout mice (Mc4r−/−). Subjects/Methods: In two separate studies, we examined the efficacy of bilateral subdiaphragmatic vagotomy (SDV) with pyloroplasty in the prevention and treatment of obesity in Mc4r−/− mice. Results: In the first study, SDV prevented >20% increase in body weight (BW) associated with this genotype. This was correlated with a transient reduction in overall food intake (FI) in the preventative arm of the study. Initially, SDV mice had reduced weekly FI; however, FI normalized to that of controls and baseline FI within the 8-week study period. In the second study, the severe obesity that is characteristic of the adult Mc4r−/− genotype was significantly improved by SDV with a magnitude of 30% loss in excess BW over a 4-week period. Consistent with the first preventative study, within the treatment arm, SDV mice also demonstrated a transient reduction in FI relative to control and baseline levels that normalized over subsequent weeks. In addition to the accompanying loss in weight, mice subjected to SDV showed a decrease in respiratory exchange ratio (RER), and an increase in locomotor activity (LA). Analysis of the white fat-pad deposits of these mice showed that they were significantly less than the control groups. Conclusions: Altogether, our data demonstrates that SDV both prevents gain in BW and causes weight loss in severely obese Mc4r−/− mice. Moreover, it suggests that an important aspect of weight reduction for this type of monogenic obesity involves loss of signaling in vagal motor neurons.
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Affiliation(s)
- Ghazaul Dezfuli
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC, United States
| | - Richard A Gillis
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC, United States
| | - Jaclyn E Tatge
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC, United States
| | - Kimbell R Duncan
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC, United States
| | - Kenneth L Dretchen
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC, United States
| | - Patrick G Jackson
- Department of Surgery, Georgetown University Medical Center, Washington, DC, United States
| | - Joseph G Verbalis
- Department of Medicine, Georgetown University Medical Center, Washington, DC, United States
| | - Niaz Sahibzada
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC, United States
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8
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Benabdelkamel H, Masood A, Almidani GM, Alsadhan AA, Bassas AF, Duncan MW, Alfadda AA. Mature adipocyte proteome reveals differentially altered protein abundances between lean, overweight and morbidly obese human subjects. Mol Cell Endocrinol 2015; 401:142-54. [PMID: 25498962 DOI: 10.1016/j.mce.2014.11.021] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Revised: 11/23/2014] [Accepted: 11/25/2014] [Indexed: 02/08/2023]
Abstract
Overweight (OW) and obese individuals are considered to be graded parts of the scale having increasing weight as a common feature. They may not, however, be part of the same continuum and may differ metabolically. In this study we applied an untargeted proteomic approach to compare protein abundances in mature adipocytes derived from the subcutaneous adipose tissue of overweight and morbidly obese female subjects to those of lean age matched controls. Mature adipocytes were isolated from liposuction samples of abdominal subcutaneous adipose tissue collected from both lean (L; n = 7, 23.3 ± 0.4 kg/m(2); mean BMI ± SD), overweight (OW; n = 8, 27.9 ± 0.6 kg/m(2); mean BMI ± SD) and morbidly obese (MOB; n = 7, 44.8 ± 3.8 kg/m(2); mean BMI ± SD) individuals. Total protein extracts were then compared by two-dimensional difference in gel electrophoresis (2D DIGE). One hundred and ten differentially expressed protein spots (i.e., fitting the statistical criteria ANOVA test, p < 0.05; fold-change ≥1.5) were detected, and of these, 89 were identified by MALDI-TOF mass spectrometry. Of these, 66 protein spots were common to both groups whereas 23 were unique to the MOB group. Significant differences were evident in the abundances of key proteins involved in glucose and lipid metabolism, energy regulation, cytoskeletal structure and redox control signaling pathways. Differences in the abundance of some chaperones were also evident. The differentially abundant proteins were investigated using Ingenuity Pathway Analysis (IPA) to establish their associations with known biological functions. The network identified in the OW group with the highest score relates to-: cell-to-cell signaling and interaction; in contrast, in the MOB group the major interacting pathways are associated with lipid metabolism, small molecule biochemistry and cancer. The differences in abundance of the differentially regulated proteins were validated by immunoblotting. These findings provide insights into metabolic differences in OW and MOB individuals.
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Affiliation(s)
- Hicham Benabdelkamel
- Obesity Research Center, College of Medicine, King Saud University, P.O. Box 2925 (98), Riyadh 11461, Saudi Arabia
| | - Afshan Masood
- Obesity Research Center, College of Medicine, King Saud University, P.O. Box 2925 (98), Riyadh 11461, Saudi Arabia
| | - Ghaith M Almidani
- Obesity Research Center, College of Medicine, King Saud University, P.O. Box 2925 (98), Riyadh 11461, Saudi Arabia
| | - Abdulmajeed A Alsadhan
- Obesity Research Center, College of Medicine, King Saud University, P.O. Box 2925 (98), Riyadh 11461, Saudi Arabia
| | - Abdulelah F Bassas
- Department of Surgery, Security Forces Hospital, P.O. Box 3643, Riyadh 11481, Saudi Arabia
| | - Mark W Duncan
- Obesity Research Center, College of Medicine, King Saud University, P.O. Box 2925 (98), Riyadh 11461, Saudi Arabia; Division of Endocrinology, Diabetes & Metabolism, Department of Medicine, School of Medicine, MS8106, E. 19th Avenue, Anschutz Medical Campus, University of Colorado Denver, Aurora, CO 80045, USA
| | - Assim A Alfadda
- Obesity Research Center, College of Medicine, King Saud University, P.O. Box 2925 (98), Riyadh 11461, Saudi Arabia; Department of Medicine, College of Medicine, King Saud University, P.O. Box 2925 (38), Riyadh 11461, Saudi Arabia.
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9
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Cotter DG, Ercal B, d'Avignon DA, Dietzen DJ, Crawford PA. Impairments of hepatic gluconeogenesis and ketogenesis in PPARα-deficient neonatal mice. Am J Physiol Endocrinol Metab 2014; 307:E176-85. [PMID: 24865983 PMCID: PMC4101633 DOI: 10.1152/ajpendo.00087.2014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Peroxisome proliferator activated receptor-α (PPARα) is a master transcriptional regulator of hepatic metabolism and mediates the adaptive response to fasting. Here, we demonstrate the roles for PPARα in hepatic metabolic adaptations to birth. Like fasting, nutrient supply is abruptly altered at birth when a transplacental source of carbohydrates is replaced by a high-fat, low-carbohydrate milk diet. PPARα-knockout (KO) neonatal mice exhibit relative hypoglycemia due to impaired conversion of glycerol to glucose. Although hepatic expression of fatty acyl-CoA dehydrogenases is imparied in PPARα neonates, these animals exhibit normal blood acylcarnitine profiles. Furthermore, quantitative metabolic fate mapping of the medium-chain fatty acid [(13)C]octanoate in neonatal mouse livers revealed normal contribution of this fatty acid to the hepatic TCA cycle. Interestingly, octanoate-derived carbon labeled glucose uniquely in livers of PPARα-KO neonates. Relative hypoketonemia in newborn PPARα-KO animals could be mechanistically linked to a 50% decrease in de novo hepatic ketogenesis from labeled octanoate. Decreased ketogenesis was associated with diminished mRNA and protein abundance of the fate-committing ketogenic enzyme mitochondrial 3-hydroxymethylglutaryl-CoA synthase (HMGCS2) and decreased protein abundance of the ketogenic enzyme β-hydroxybutyrate dehydrogenase 1 (BDH1). Finally, hepatic triglyceride and free fatty acid concentrations were increased 6.9- and 2.7-fold, respectively, in suckling PPARα-KO neonates. Together, these findings indicate a primary defect of gluconeogenesis from glycerol and an important role for PPARα-dependent ketogenesis in the disposal of hepatic fatty acids during the neonatal period.
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Affiliation(s)
- David G Cotter
- Department of Medicine, Center for Cardiovascular Research, and Departments of Pediatrics
| | - Baris Ercal
- Department of Medicine, Center for Cardiovascular Research, and
| | | | | | - Peter A Crawford
- Department of Medicine, Center for Cardiovascular Research, and Genetics, Washington University, St. Louis, Missouri
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10
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Biomedically relevant circuit-design strategies in mammalian synthetic biology. Mol Syst Biol 2014; 9:691. [PMID: 24061539 PMCID: PMC3792348 DOI: 10.1038/msb.2013.48] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Accepted: 08/07/2013] [Indexed: 12/24/2022] Open
Abstract
The development and progress in synthetic biology has been remarkable. Although still in its infancy, synthetic biology has achieved much during the past decade. Improvements in genetic circuit design have increased the potential for clinical applicability of synthetic biology research. What began as simple transcriptional gene switches has rapidly developed into a variety of complex regulatory circuits based on the transcriptional, translational and post-translational regulation. Instead of compounds with potential pharmacologic side effects, the inducer molecules now used are metabolites of the human body and even members of native cell signaling pathways. In this review, we address recent progress in mammalian synthetic biology circuit design and focus on how novel designs push synthetic biology toward clinical implementation. Groundbreaking research on the implementation of optogenetics and intercellular communications is addressed, as particularly optogenetics provides unprecedented opportunities for clinical application. Along with an increase in synthetic network complexity, multicellular systems are now being used to provide a platform for next-generation circuit design.
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11
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Heng BC, Aubel D, Fussenegger M. G protein-coupled receptors revisited: therapeutic applications inspired by synthetic biology. Annu Rev Pharmacol Toxicol 2013; 54:227-49. [PMID: 24160705 DOI: 10.1146/annurev-pharmtox-011613-135921] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
G protein-coupled receptors (GPCRs) mediate the majority of cellular responses to hormones and neurotransmitters within the human body. They have much potential in the emerging field of synthetic biology, which is the rational, systematic design of biological systems with desired functionality. The responsiveness of GPCRs to a plethora of endogenous and exogenous ligands and stimuli make them ideal sensory receptor modules of synthetic gene networks. Such networks can activate target gene expression in response to a specific stimulus. Additionally, because GPCRs are important pharmacological targets of various human diseases, genes encoding their protein/peptide ligands can also be incorporated as target genes of the response output elements of synthetic gene networks. This review aims to critically examine the potential role of GPCRs in constructing therapeutic synthetic gene networks and to discuss various challenges in utilizing GPCRs for synthetic biology applications.
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Affiliation(s)
- Boon Chin Heng
- Department of Biosystems Science and Engineering, ETH Zürich, CH-4058 Basel, Switzerland;
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12
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Templeton N, Dean J, Reddy P, Young JD. Peak antibody production is associated with increased oxidative metabolism in an industrially relevant fed-batch CHO cell culture. Biotechnol Bioeng 2013; 110:2013-24. [PMID: 23381838 DOI: 10.1002/bit.24858] [Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 01/11/2013] [Accepted: 01/22/2013] [Indexed: 12/18/2022]
Abstract
Cell metabolism can vary considerably over the course of a typical fed-batch antibody production process. However, the intracellular pathway alterations associated with various phases of growth and antibody production have yet to be fully elucidated using industrially relevant production hosts. Therefore, we performed (13)C labeling experiments and metabolic flux analysis (MFA) to characterize CHO cell metabolism during four separate phases of a fed-batch culture designed to closely represent industrial process conditions. First, we found that peak specific growth rate was associated with high lactate production and minimal TCA cycling. Conversely, we found that lactate metabolism switched from net production to net consumption as the culture transitioned from peak growth to peak antibody production. During the peak antibody production phase, energy was primarily generated through oxidative phosphorylation, which was also associated with elevated oxidative pentose phosphate pathway (oxPPP) activity. Interestingly, as TCA cycling and antibody production reached their peaks, specific growth rate continued to diminish as the culture entered stationary phase. However, TCA cycling and oxPPP activity remained high even as viable cell density began to decline. Overall, we found that a highly oxidative state of metabolism corresponded with peak antibody production, whereas peak cell growth was characterized by a highly glycolytic metabolic state.
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Affiliation(s)
- Neil Templeton
- Chemical and Biomolecular Engineering, Vanderbilt University, PMB 351604, Nashville, TN 37235, USA
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13
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Dean J, Reddy P. Metabolic analysis of antibody producing CHO cells in fed-batch production. Biotechnol Bioeng 2013; 110:1735-47. [DOI: 10.1002/bit.24826] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 10/27/2012] [Accepted: 12/17/2012] [Indexed: 12/19/2022]
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14
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Abstract
Synthetic biology, application of synthetic chemistry to biology, is a broad term that covers the engineering of biological systems with structures and functions not found in nature to process information, manipulate chemicals, produce energy, maintain cell environment and enhance human health. Synthetic biology devices contribute not only to improve our understanding of disease mechanisms, but also provide novel diagnostic tools. Methods based on synthetic biology enable the design of novel strategies for the treatment of cancer, immune diseases metabolic disorders and infectious diseases as well as the production of cheap drugs. The potential of synthetic genome, using an expanded genetic code that is designed for specific drug synthesis as well as delivery and activation of the drug in vivo by a pathological signal, was already pointed out during a lecture delivered at Kuwait University in 2005. Of two approaches to synthetic biology, top-down and bottom-up, the latter is more relevant to the development of personalized medicines as it provides more flexibility in constructing a partially synthetic cell from basic building blocks for a desired task.
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Affiliation(s)
- K K Jain
- PharmaBiotech, Basel, Switzerland.
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15
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Mardinoglu A, Agren R, Kampf C, Asplund A, Nookaew I, Jacobson P, Walley AJ, Froguel P, Carlsson LM, Uhlen M, Nielsen J. Integration of clinical data with a genome-scale metabolic model of the human adipocyte. Mol Syst Biol 2013; 9:649. [PMID: 23511207 PMCID: PMC3619940 DOI: 10.1038/msb.2013.5] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 02/11/2013] [Indexed: 12/18/2022] Open
Abstract
We evaluated the presence/absence of proteins encoded by 14 077 genes in adipocytes obtained from different tissue samples using immunohistochemistry. By combining this with previously published adipocyte-specific proteome data, we identified proteins associated with 7340 genes in human adipocytes. This information was used to reconstruct a comprehensive and functional genome-scale metabolic model of adipocyte metabolism. The resulting metabolic model, iAdipocytes1809, enables mechanistic insights into adipocyte metabolism on a genome-wide level, and can serve as a scaffold for integration of omics data to understand the genotype-phenotype relationship in obese subjects. By integrating human transcriptome and fluxome data, we found an increase in the metabolic activity around androsterone, ganglioside GM2 and degradation products of heparan sulfate and keratan sulfate, and a decrease in mitochondrial metabolic activities in obese subjects compared with lean subjects. Our study hereby shows a path to identify new therapeutic targets for treating obesity through combination of high throughput patient data and metabolic modeling.
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Affiliation(s)
- Adil Mardinoglu
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Rasmus Agren
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Caroline Kampf
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Anna Asplund
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Intawat Nookaew
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Peter Jacobson
- Department of Molecular and Clinical Medicine and Center for Cardiovascular and Metabolic Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Andrew J Walley
- Department of Genomics of Common Diseases, School of Public Health, Imperial College London, Hammersmith Hospital, London, UK
| | - Philippe Froguel
- Department of Genomics of Common Diseases, School of Public Health, Imperial College London, Hammersmith Hospital, London, UK
- Unité Mixte de Recherche 8199, Centre National de Recherche Scientifique (CNRS) and Pasteur Institute, Lille, France
| | - Lena M Carlsson
- Department of Molecular and Clinical Medicine and Center for Cardiovascular and Metabolic Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Mathias Uhlen
- Department of Proteomics, School of Biotechnology, AlbaNova University Center, Royal Institute of Technology (KTH), Stockholm, Sweden
| | - Jens Nielsen
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
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16
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Design and Application of Synthetic Biology Devices for Therapy. Synth Biol (Oxf) 2013. [DOI: 10.1016/b978-0-12-394430-6.00009-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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17
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Folcher M, Fussenegger M. Synthetic biology advancing clinical applications. Curr Opin Chem Biol 2012; 16:345-54. [DOI: 10.1016/j.cbpa.2012.06.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 05/31/2012] [Accepted: 06/20/2012] [Indexed: 10/28/2022]
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18
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Synthetic Biology: Its Applications in Biotechnology*. PROG BIOCHEM BIOPHYS 2012. [DOI: 10.3724/sp.j.1206.2011.00583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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19
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Birkenfeld AL, Lee HY, Guebre-Egziabher F, Alves TC, Jurczak MJ, Jornayvaz FR, Zhang D, Hsiao JJ, Martin-Montalvo A, Fischer-Rosinsky A, Spranger J, Pfeiffer AF, Jordan J, Fromm MF, König J, Lieske S, Carmean CM, Frederick DW, Weismann D, Knauf F, Irusta PM, De Cabo R, Helfand SL, Samuel VT, Shulman GI. Deletion of the mammalian INDY homolog mimics aspects of dietary restriction and protects against adiposity and insulin resistance in mice. Cell Metab 2011; 14:184-95. [PMID: 21803289 PMCID: PMC3163140 DOI: 10.1016/j.cmet.2011.06.009] [Citation(s) in RCA: 165] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Revised: 12/24/2010] [Accepted: 06/07/2011] [Indexed: 01/07/2023]
Abstract
Reduced expression of the Indy (I'm Not Dead, Yet) gene in D. melanogaster and its homolog in C. elegans prolongs life span and in D. melanogaster augments mitochondrial biogenesis in a manner akin to caloric restriction. However, the cellular mechanism by which Indy does this is unknown. Here, we report on the knockout mouse model of the mammalian Indy (mIndy) homolog, SLC13A5. Deletion of mIndy in mice (mINDY(-/-) mice) reduces hepatocellular ATP/ADP ratio, activates hepatic AMPK, induces PGC-1α, inhibits ACC-2, and reduces SREBP-1c levels. This signaling network promotes hepatic mitochondrial biogenesis, lipid oxidation, and energy expenditure and attenuates hepatic de novo lipogenesis. Together, these traits protect mINDY(-/-) mice from the adiposity and insulin resistance that evolve with high-fat feeding and aging. Our studies demonstrate a profound effect of mIndy on mammalian energy metabolism and suggest that mINDY might be a therapeutic target for the treatment of obesity and type 2 diabetes.
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Affiliation(s)
- Andreas L Birkenfeld
- Howard Hughes Medical Institute, Yale School of Medicine, New Haven, CT 06520, USA
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20
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Kaleta C, de Figueiredo LF, Werner S, Guthke R, Ristow M, Schuster S. In silico evidence for gluconeogenesis from fatty acids in humans. PLoS Comput Biol 2011; 7:e1002116. [PMID: 21814506 PMCID: PMC3140964 DOI: 10.1371/journal.pcbi.1002116] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Accepted: 05/24/2011] [Indexed: 11/25/2022] Open
Abstract
The question whether fatty acids can be converted into glucose in humans has a long standing tradition in biochemistry, and the expected answer is “No”. Using recent advances in Systems Biology in the form of large-scale metabolic reconstructions, we reassessed this question by performing a global investigation of a genome-scale human metabolic network, which had been reconstructed on the basis of experimental results. By elementary flux pattern analysis, we found numerous pathways on which gluconeogenesis from fatty acids is feasible in humans. On these pathways, four moles of acetyl-CoA are converted into one mole of glucose and two moles of CO2. Analyzing the detected pathways in detail we found that their energetic requirements potentially limit their capacity. This study has many other biochemical implications: effect of starvation, sports physiology, practically carbohydrate-free diets of inuit, as well as survival of hibernating animals and embryos of egg-laying animals. Moreover, the energetic loss associated to the usage of gluconeogenesis from fatty acids can help explain the efficiency of carbohydrate reduced and ketogenic diets such as the Atkins diet. That sugar can be converted into fatty acids in humans is a well-known fact. The question whether the reverse direction, i.e., gluconeogenesis from fatty acids, is also feasible has been a topic of intense debate since the end of the 19th century. With the discovery of the glyoxylate shunt that allows this conversion in some bacteria, plants, fungi and nematodes it has been considered infeasible in humans since the corresponding enzymes could not be detected. However, by this finding only a single route for gluconeogenesis from fatty acids has been ruled out. To address the question whether there might exist alternative routes in humans we searched for gluconeogenic routes from fatty acids in a metabolic network comprising all reactions known to take place in humans. Thus, we were able to identify several pathways showing that this conversion is indeed feasible. Analyzing evidence concerning the detected pathways lends support to their importance during times of starvation, fasting, carbohydrate reduced and ketogenic diets and other situations in which the nutrition is low on carbohydrates. Moreover, the energetic investment required for this pathway can help to explain the particular efficiency of carbohydrate reduced and ketogenic diets such as the Atkins diet.
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Affiliation(s)
- Christoph Kaleta
- Department of Bioinformatics, School of Biology and Pharmaceutics, Friedrich Schiller University of Jena, Jena, Germany.
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Dean JT, Rizk ML, Tan Y, Dipple KM, Liao JC. Ensemble modeling of hepatic fatty acid metabolism with a synthetic glyoxylate shunt. Biophys J 2010; 98:1385-95. [PMID: 20409457 DOI: 10.1016/j.bpj.2009.12.4308] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 12/06/2009] [Accepted: 12/11/2009] [Indexed: 11/29/2022] Open
Abstract
The liver plays a central role in maintaining whole body metabolic and energy homeostasis by consuming and producing glucose and fatty acids. Glucose and fatty acids compete for hepatic substrate oxidation with regulation ensuring glucose is oxidized preferentially. Increasing fatty acid oxidation is expected to decrease lipid storage in the liver and avoid lipid-induced insulin-resistance. To increase hepatic lipid oxidation in the presence of glucose, we previously engineered a synthetic glyoxylate shunt into human hepatocyte cultures and a mouse model and showed that this synthetic pathway increases free fatty acid beta-oxidation and confers resistance to diet-induced obesity in the mouse model. Here we used ensemble modeling to decipher the effects of perturbations to the hepatic metabolic network on fatty acid oxidation and glucose uptake. Despite sampling of kinetic parameters using the most fundamental elementary reaction models, the models based on current metabolic regulation did not readily describe the phenotype generated by glyoxylate shunt expression. Although not conclusive, this initial negative result prompted us to probe unknown regulations, and malate was identified as inhibitor of hexokinase 2 expression either through direct or indirect actions. This regulation allows the explanation of observed phenotypes (increased fatty acid degradation and decreased glucose consumption). Moreover, the result is a function of pyruvate-carboxylase, mitochondrial pyruvate transporter, citrate transporter protein, and citrate synthase activities. Some subsets of these flux ratios predict increases in fatty acid and decreases in glucose uptake after glyoxylate expression, whereas others predict no change. Altogether, this work defines the possible biochemical space where the synthetic shunt will produce the desired phenotype and demonstrates the efficacy of ensemble modeling for synthetic pathway design.
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Affiliation(s)
- Jason T Dean
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California, USA
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22
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Abstract
Early synthetic biology designs, namely the genetic toggle switch and repressilator, showed that regulatory components can be characterized and assembled to bring about complex, electronics-inspired behaviours in living systems (for example, memory storage and timekeeping). Through the characterization and assembly of genetic parts and biological building blocks, many more devices have been constructed, including switches, memory elements, oscillators, pulse generators, digital logic gates, filters and communication modules. Advances in the field are now allowing expansion beyond small gene networks to the realm of larger biological programs, which hold promise for a wide range of applications, including biosensing, therapeutics and the production of biofuels, pharmaceuticals and biomaterials. Synthetic biosensing circuits consist of sensitive elements that bind analytes and transducer modules that mobilize cellular responses. Balancing these two modules involves engineering modularity and specificity into the various circuits. Biosensor sensitive elements include environment-responsive promoters (transcriptional), RNA aptamers (translational) and protein receptors (post-translational). Biosensor transducer modules include engineered gene networks (transcriptional), non-coding regulatory RNAs (translational) and protein signal-transduction circuits (post-translational). The contributions of synthetic biology to therapeutics include: engineered networks and organisms for disease-mechanism elucidation, drug-target identification, drug-discovery platforms, therapeutic treatment, therapeutic delivery, and drug production and access. In the microbial production of biofuels and pharmaceuticals, synthetic biology has supplemented traditional genetic and metabolic engineering efforts by aiding the construction of optimized biosynthetic pathways. Optimizing metabolic flux through biosynthetic pathways is traditionally accomplished by driving the expression of pathway enzymes with strong, inducible promoters. New synthetic approaches include the rapid diversification of various pathway components, the rational and model-guided assembly of pathway components, and hybrid solutions.
Advances in the synthetic biology field are allowing an expansion beyond small gene networks towards larger biological programs that hold promise for a wide range of applications, including biosensing, therapeutics and the production of biofuels, pharmaceuticals and biomaterials. Synthetic biology is bringing together engineers and biologists to design and build novel biomolecular components, networks and pathways, and to use these constructs to rewire and reprogram organisms. These re-engineered organisms will change our lives over the coming years, leading to cheaper drugs, 'green' means to fuel our cars and targeted therapies for attacking 'superbugs' and diseases, such as cancer. The de novo engineering of genetic circuits, biological modules and synthetic pathways is beginning to address these crucial problems and is being used in related practical applications.
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Affiliation(s)
- Ahmad S Khalil
- Howard Hughes Medical Institute, Department of Biomedical Engineering, Center for BioDynamics and Center for Advanced Biotechnology, Boston University, Boston, Massachusetts 02215, USA
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Self-sufficient control of urate homeostasis in mice by a synthetic circuit. Nat Biotechnol 2010; 28:355-60. [DOI: 10.1038/nbt.1617] [Citation(s) in RCA: 209] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 02/19/2010] [Indexed: 02/07/2023]
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25
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Obese and anorexic yeasts: Experimental models to understand the metabolic syndrome and lipotoxicity. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:222-9. [DOI: 10.1016/j.bbalip.2009.12.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2009] [Revised: 12/23/2009] [Accepted: 12/24/2009] [Indexed: 12/23/2022]
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26
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Abstract
In this issue of Cell Metabolism, Liao and colleagues have applied a novel synthetic approach to fight obesity in animals by engineering the plant glyoxylate shunt in vivo (Dean et al., 2009). The idea of introducing an entirely foreign metabolic pathway opens up opportunities for understanding metabolism and creating novel potential therapeutic approaches.
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Affiliation(s)
- Liming Pei
- Howard Hughes Medical Institute and Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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