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Kuo A, Hla T. Regulation of cellular and systemic sphingolipid homeostasis. Nat Rev Mol Cell Biol 2024:10.1038/s41580-024-00742-y. [PMID: 38890457 DOI: 10.1038/s41580-024-00742-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2024] [Indexed: 06/20/2024]
Abstract
One hundred and fifty years ago, Johann Thudichum described sphingolipids as unusual "Sphinx-like" lipids from the brain. Today, we know that thousands of sphingolipid molecules mediate many essential functions in embryonic development and normal physiology. In addition, sphingolipid metabolism and signalling pathways are dysregulated in a wide range of pathologies, and therapeutic agents that target sphingolipids are now used to treat several human diseases. However, our understanding of sphingolipid regulation at cellular and organismal levels and their functions in developmental, physiological and pathological settings is rudimentary. In this Review, we discuss recent advances in sphingolipid pathways in different organelles, how secreted sphingolipid mediators modulate physiology and disease, progress in sphingolipid-targeted therapeutic and diagnostic research, and the trans-cellular sphingolipid metabolic networks between microbiota and mammals. Advances in sphingolipid biology have led to a deeper understanding of mammalian physiology and may lead to progress in the management of many diseases.
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Affiliation(s)
- Andrew Kuo
- Vascular Biology Program, Boston Children's Hospital, Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Timothy Hla
- Vascular Biology Program, Boston Children's Hospital, Department of Surgery, Harvard Medical School, Boston, MA, USA.
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2
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Ma S, Sandhoff R, Luo X, Shang F, Shi Q, Li Z, Wu J, Ming Y, Schwarz F, Madi A, Weisshaar N, Mieg A, Hering M, Zettl F, Yan X, Mohr K, Ten Bosch N, Li Z, Poschet G, Rodewald HR, Papavasiliou N, Wang X, Gao P, Cui G. Serine enrichment in tumors promotes regulatory T cell accumulation through sphinganine-mediated regulation of c-Fos. Sci Immunol 2024; 9:eadg8817. [PMID: 38640251 DOI: 10.1126/sciimmunol.adg8817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 03/15/2024] [Indexed: 04/21/2024]
Abstract
CD4+ regulatory T (Treg) cells accumulate in the tumor microenvironment (TME) and suppress the immune system. Whether and how metabolite availability in the TME influences Treg cell differentiation is not understood. Here, we measured 630 metabolites in the TME and found that serine and palmitic acid, substrates required for the synthesis of sphingolipids, were enriched. A serine-free diet or a deficiency in Sptlc2, the rate-limiting enzyme catalyzing sphingolipid synthesis, suppressed Treg cell accumulation and inhibited tumor growth. Sphinganine, an intermediate metabolite in sphingolipid synthesis, physically interacted with the transcription factor c-Fos. Sphinganine c-Fos interactions enhanced the genome-wide recruitment of c-Fos to regions near the transcription start sites of target genes including Pdcd1 (encoding PD-1), which promoted Pdcd1 transcription and increased inducible Treg cell differentiation in vitro in a PD-1-dependent manner. Thus, Sptlc2-mediated sphingolipid synthesis translates the extracellular information of metabolite availability into nuclear signals for Treg cell differentiation and limits antitumor immunity.
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Affiliation(s)
- Sicong Ma
- Key Laboratory of Immune Response and Immunotherapy, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230601, China
| | - Roger Sandhoff
- Lipid Pathobiochemistry Group (A411), 69120 Heidelberg, Germany
| | - Xiu Luo
- CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Fuwei Shang
- Cellular Immunology (D110), German Cancer Research Center, 69120 Heidelberg, Germany
- Faculty of Medicine, Heidelberg University, Heidelberg, Germany
| | - Qiaozhen Shi
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Zhaolong Li
- CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Jingxia Wu
- Key Laboratory of Immune Response and Immunotherapy, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230601, China
| | - Yanan Ming
- Key Laboratory of Immune Response and Immunotherapy, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230601, China
| | - Frank Schwarz
- Core Facility Antibodies (W170), German Cancer Research Center, 69120 Heidelberg, Germany
| | - Alaa Madi
- Immune Diversity (D150), German Cancer Research Center, 69120 Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Nina Weisshaar
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
- T Cell Metabolism (D192), German Cancer Research Center, 69120 Heidelberg, Germany
| | - Alessa Mieg
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
- T Cell Metabolism (D192), German Cancer Research Center, 69120 Heidelberg, Germany
| | - Marvin Hering
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
- T Cell Metabolism (D192), German Cancer Research Center, 69120 Heidelberg, Germany
| | - Ferdinand Zettl
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
- T Cell Metabolism (D192), German Cancer Research Center, 69120 Heidelberg, Germany
| | - Xin Yan
- Immune Diversity (D150), German Cancer Research Center, 69120 Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Kerstin Mohr
- T Cell Metabolism (D192), German Cancer Research Center, 69120 Heidelberg, Germany
| | - Nora Ten Bosch
- T Cell Metabolism (D192), German Cancer Research Center, 69120 Heidelberg, Germany
| | - Zhe Li
- Division of Pathogenesis of Virus Associated Tumors (F100), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Gernot Poschet
- Metabolomics Core Technology Platform, Centre for Organismal Studies (COS), Heidelberg University, 69120 Heidelberg, Germany
| | - Hans-Reimer Rodewald
- Cellular Immunology (D110), German Cancer Research Center, 69120 Heidelberg, Germany
| | - Nina Papavasiliou
- Immune Diversity (D150), German Cancer Research Center, 69120 Heidelberg, Germany
| | - Xi Wang
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Pu Gao
- CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Guoliang Cui
- Key Laboratory of Immune Response and Immunotherapy, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230601, China
- T Cell Metabolism (D192), German Cancer Research Center, 69120 Heidelberg, Germany
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Li Z, He M, Chen G, Souaiaia T, Worgall TS, Jiang XC. Effect of Total SMS Activity on LDL Catabolism in Mice. Arterioscler Thromb Vasc Biol 2023; 43:1251-1261. [PMID: 37128925 PMCID: PMC10330209 DOI: 10.1161/atvbaha.123.319031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 04/06/2023] [Indexed: 05/03/2023]
Abstract
BACKGROUND Sphingomyelin (SM) and cholesterol are 2 key lipid partners on cell membranes and on lipoproteins. Many studies have indicated the influence of cholesterol on SM metabolism. This study examined the influence of SM biosynthesis on cholesterol metabolism. METHODS Inducible global Sms1 KO (knockout)/global Sms2 KO mice were prepared to evaluate the effect of whole-body SM biosynthesis deficiency on lipoprotein metabolism. Tissue cholesterol, SM, ceramide, and glucosylceramide levels were measured. Triglyceride production rate and LDL (low-density lipoprotein) catabolism were measured. Lipid rafts were isolated and LDL receptor mass and function were evaluated. Also, the effects of exogenous sphingolipids on hepatocytes were investigated. RESULTS We found that total SMS (SM synthase) depletion significantly reduced plasma SM levels. Also, the total deficiency significantly induced plasma cholesterol, apoB (apolipoprotein B), and apoE (apolipoprotein E) levels. Importantly, total SMS deficiency, but not SMS2 deficiency, dramatically decreased LDL receptors in the liver and attenuated LDL uptake through the receptor. Further, we found that total SMS deficiency greatly reduced LDL receptors in the lipid rafts, which contained significantly lower SM and significantly higher glucosylceramide, as well as cholesterol. Furthermore, we treated primary hepatocytes and Huh7 cells (a human hepatoma cell line) with SM, ceramide, or glucosylceramide, and we found that only SM could upregulate LDL receptor levels in a dose-dependent fashion. CONCLUSIONS Whole-body SM biosynthesis plays an important role in LDL cholesterol catabolism. The total SMS deficiency, but not SMS2 deficiency, reduces LDL uptake and causes LDL cholesterol accumulation in the circulation. Given the fact that serum SM level is a risk factor for cardiovascular diseases, inhibiting SMS2 but not SMS1 should be the desirable approach.
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Affiliation(s)
- Zhiqiang Li
- Department of Cell Biology, State University of New York, Downstate Health Sciences University, Brooklyn (Z.L., M.H., G.C., T.S., X.-C.J.)
- Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System (Z.L., X.-C.J.)
| | - Mulin He
- Department of Cell Biology, State University of New York, Downstate Health Sciences University, Brooklyn (Z.L., M.H., G.C., T.S., X.-C.J.)
| | - Guangzhi Chen
- Department of Cell Biology, State University of New York, Downstate Health Sciences University, Brooklyn (Z.L., M.H., G.C., T.S., X.-C.J.)
| | - Tade Souaiaia
- Department of Cell Biology, State University of New York, Downstate Health Sciences University, Brooklyn (Z.L., M.H., G.C., T.S., X.-C.J.)
| | - Tilla S Worgall
- Department of Pathology and Cell Biology, Columbia University, New York (T.S.W.)
| | - Xian-Cheng Jiang
- Department of Cell Biology, State University of New York, Downstate Health Sciences University, Brooklyn (Z.L., M.H., G.C., T.S., X.-C.J.)
- Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System (Z.L., X.-C.J.)
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Effect of Total Sphingomyelin Synthase Activity on Low Density Lipoprotein Catabolism in Mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.03.527088. [PMID: 36798262 PMCID: PMC9934588 DOI: 10.1101/2023.02.03.527088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Background Sphingomyelin (SM) and cholesterol are two key lipid partners on cell membranes and on lipoproteins. Many studies have indicated the influence of cholesterol on SM metabolism. This study examined the influence of SM biosynthesis on cholesterol metabolism. Methods Inducible global Sms1 KO/global Sms2 KO mice were prepared to evaluate the effect of whole-body SM biosynthesis deficiency on lipoprotein metabolism. Tissue cholesterol, SM, ceramide, and glucosylceramide levels were measured. TG production rate and LDL catabolism were measured. Lipid rafts were isolated and LDL receptor mass and function were evaluated. Also, the effects of exogenous sphingolipids on hepatocytes were investigated. Results We found that total SMS depletion significantly reduced plasma SM levels. Also, the total deficiency significantly induced plasma cholesterol, apoB, and apoE levels. Importantly, total SMS deficiency, but not SMS2 deficiency, dramatically decreased LDL receptors in the liver and attenuated LDL uptake through the receptor. Further, we found that total SMS deficiency greatly reduced LDL receptors in the lipid rafts which contained significantly lower SM and significantly higher glucosylceramide as well as cholesterol. Furthermore, we treated primary hepatocytes and Huh7 cells (a human hepatoma cell line) with SM, ceramide, or glucosylceramide, and we found that only SM could up-regulate LDL receptor levels in a dose-dependent fashion. Conclusions Whole-body SM biosynthesis plays an important role in LDL-cholesterol catabolism. The total SMS deficiency, but not SMS2 deficiency, reduces LDL uptake and causes LDL-cholesterol accumulation in the circulation. Given the fact that serum SM level is a risk factor for cardiovascular diseases, inhibiting SMS2 but not SMS1 should be the desirable approach. Graphic Abstract
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5
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Kim GT, Devi S, Sharma A, Cho KH, Kim SJ, Kim BR, Kwon SH, Park TS. Upregulation of the serine palmitoyltransferase subunit SPTLC2 by endoplasmic reticulum stress inhibits the hepatic insulin response. Exp Mol Med 2022; 54:573-584. [PMID: 35513574 PMCID: PMC9166747 DOI: 10.1038/s12276-022-00766-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 12/13/2021] [Accepted: 12/30/2021] [Indexed: 11/27/2022] Open
Abstract
Endoplasmic reticulum (ER) stress is induced by various conditions, such as inflammation and the presence of excess nutrients. Abnormal accumulation of unfolded proteins leads to the activation of a collective signaling cascade, termed the unfolded protein response (UPR). ER stress is reported to perturb hepatic insulin response metabolism while promoting insulin resistance. Here, we report that ER stress regulates the de novo biosynthesis of sphingolipids via the activation of serine palmitoyltransferase (SPT), a rate-limiting enzyme involved in the de novo biosynthesis of ceramides. We found that the expression levels of Sptlc1 and Sptlc2, the major SPT subunits, were upregulated and that the cellular concentrations of ceramide and dihydroceramide were elevated by acute ER stress inducers in primary hepatocytes and HepG2 cells. Sptlc2 was upregulated and ceramide levels were elevated by tunicamycin in the livers of C57BL/6J wild-type mice. Analysis of the Sptlc2 promoter demonstrated that the transcriptional activation of Sptlc2 was mediated by the spliced form of X-box binding protein 1 (sXBP1). Liver-specific Sptlc2 transgenic mice exhibited increased ceramide levels in the liver and elevated fasting glucose levels. The insulin response was reduced by the inhibition of the phosphorylation of insulin receptor β (IRβ). Collectively, these results demonstrate that ER stress induces activation of the de novo biosynthesis of ceramide and contributes to the progression of hepatic insulin resistance via the reduced phosphorylation of IRβ in hepatocytes. A lipid molecule called ceramide is key to regulating the body’s insulin response, which controls blood sugar, and thus may hold keys to new treatments for metabolic diseases such as diabetes. Although ceramide levels were known to be raised in obesity and diabetes, the mechanism remained unclear. Tae-Sik Park at Gachon University, Sungnam, South Korea, and Sang-Ho Kwon at Augusta University, USA, and co-workers investigated how excess ceramide production is triggered and the blood sugar regulation consequences. They found that the liver-specific SPTLC2 transgenic mice fed a high-fat diet had increased levels of an enzyme activity of serine palmitoyltransferase which led to synthesis of high levels of ceramide in the liver. The high ceramide levels suppressed insulin signaling, imbalancing blood sugar levels and causing liver toxicity. Therapies that inhibit ceramide synthesis show promise for treatment of metabolic diseases.
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Affiliation(s)
- Goon-Tae Kim
- Department of Life Science, Gachon University, Sungnam, Korea
| | - Shivani Devi
- Department of Life Science, Gachon University, Sungnam, Korea
| | - Amitesh Sharma
- Department of Life Science, Gachon University, Sungnam, Korea
| | - Kyung-Hee Cho
- Department of Life Science, Gachon University, Sungnam, Korea
| | - Su-Jung Kim
- Biomedical Research Center, Asan Institute for Life Sciences, Seoul, Korea
| | - Bo-Rahm Kim
- The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea
| | - Sang-Ho Kwon
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.
| | - Tae-Sik Park
- Department of Life Science, Gachon University, Sungnam, Korea. .,Lipidomia Inc., Sungnam, Korea.
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6
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Kuo A, Checa A, Niaudet C, Jung B, Fu Z, Wheelock CE, Singh SA, Aikawa M, Smith LE, Proia RL, Hla T. Murine endothelial serine palmitoyltransferase 1 (SPTLC1) is required for vascular development and systemic sphingolipid homeostasis. eLife 2022; 11:78861. [PMID: 36197001 PMCID: PMC9578713 DOI: 10.7554/elife.78861] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 10/04/2022] [Indexed: 02/04/2023] Open
Abstract
Serine palmitoyl transferase (SPT), the rate-limiting enzyme in the de novo synthesis of sphingolipids (SL), is needed for embryonic development, physiological homeostasis, and response to stress. The functions of de novo SL synthesis in vascular endothelial cells (EC), which line the entire circulatory system, are not well understood. Here, we show that the de novo SL synthesis in EC not only regulates vascular development but also maintains circulatory and peripheral organ SL levels. Mice with an endothelial-specific gene knockout of SPTLC1 (Sptlc1 ECKO), an essential subunit of the SPT complex, exhibited reduced EC proliferation and tip/stalk cell differentiation, resulting in delayed retinal vascular development. In addition, Sptlc1 ECKO mice had reduced retinal neovascularization in the oxygen-induced retinopathy model. Mechanistic studies suggest that EC SL produced from the de novo pathway are needed for lipid raft formation and efficient VEGF signaling. Post-natal deletion of the EC Sptlc1 also showed rapid reduction of several SL metabolites in plasma, red blood cells, and peripheral organs (lung and liver) but not in the retina, part of the central nervous system (CNS). In the liver, EC de novo SL synthesis was important for acetaminophen-induced rapid ceramide elevation and hepatotoxicity. These results suggest that EC-derived SL metabolites are in constant flux between the vasculature, circulatory elements, and parenchymal cells of non-CNS organs. Taken together, our data point to the central role of the endothelial SL biosynthesis in maintaining vascular development, neovascular proliferation, non-CNS tissue metabolic homeostasis, and hepatocyte response to stress.
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Affiliation(s)
- Andrew Kuo
- Vascular Biology Program, Boston Children’s Hospital, Department of Surgery, Harvard Medical SchoolBostonUnited States
| | - Antonio Checa
- Unit of Integrative Metabolomics, Institute of Environmental Medicine, Karolinska InstituteStockholmSweden
| | - Colin Niaudet
- Vascular Biology Program, Boston Children’s Hospital, Department of Surgery, Harvard Medical SchoolBostonUnited States
| | - Bongnam Jung
- Vascular Biology Program, Boston Children’s Hospital, Department of Surgery, Harvard Medical SchoolBostonUnited States
| | - Zhongjie Fu
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical SchoolBostonUnited States
| | - Craig E Wheelock
- Unit of Integrative Metabolomics, Institute of Environmental Medicine, Karolinska InstituteStockholmSweden,Department of Respiratory Medicine and Allergy, Karolinska University HospitalStockholmSweden,Gunma University Initiative for Advanced Research, Gunma UniversityMaebashiJapan
| | - Sasha A Singh
- Center for Interdisciplinary Cardiovascular Sciences, Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical SchoolBostonUnited States
| | - Masanori Aikawa
- Center for Interdisciplinary Cardiovascular Sciences, Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical SchoolBostonUnited States
| | - Lois E Smith
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical SchoolBostonUnited States
| | - Richard L Proia
- Genetics and Biochemistry Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesdaUnited States
| | - Timothy Hla
- Vascular Biology Program, Boston Children’s Hospital, Department of Surgery, Harvard Medical SchoolBostonUnited States
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Wang T, Wang Z, de Fabritus L, Tao J, Saied EM, Lee HJ, Ramazanov BR, Jackson B, Burkhardt D, Parker M, Gleinich AS, Wang Z, Seo DE, Zhou T, Xu S, Alecu I, Azadi P, Arenz C, Hornemann T, Krishnaswamy S, van de Pavert SA, Kaech SM, Ivanova NB, Santori FR. 1-deoxysphingolipids bind to COUP-TF to modulate lymphatic and cardiac cell development. Dev Cell 2021; 56:3128-3145.e15. [PMID: 34762852 PMCID: PMC8628544 DOI: 10.1016/j.devcel.2021.10.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 08/30/2021] [Accepted: 10/19/2021] [Indexed: 12/12/2022]
Abstract
Identification of physiological modulators of nuclear hormone receptor (NHR) activity is paramount for understanding the link between metabolism and transcriptional networks that orchestrate development and cellular physiology. Using libraries of metabolic enzymes alongside their substrates and products, we identify 1-deoxysphingosines as modulators of the activity of NR2F1 and 2 (COUP-TFs), which are orphan NHRs that are critical for development of the nervous system, heart, veins, and lymphatic vessels. We show that these non-canonical alanine-based sphingolipids bind to the NR2F1/2 ligand-binding domains (LBDs) and modulate their transcriptional activity in cell-based assays at physiological concentrations. Furthermore, inhibition of sphingolipid biosynthesis phenocopies NR2F1/2 deficiency in endothelium and cardiomyocytes, and increases in 1-deoxysphingosine levels activate NR2F1/2-dependent differentiation programs. Our findings suggest that 1-deoxysphingosines are physiological regulators of NR2F1/2-mediated transcription.
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Affiliation(s)
- Ting Wang
- Department of Immunobiology, Yale University, New Haven, CT 06520, USA; Department of Hematology, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Zheng Wang
- Department of Genetics and Cell Biology, Basic Medical College, Qingdao University, Qingdao, Shandong 266071, China; Department of Reproductive Medicine, the Affiliated Hospital of Qingdao University, Qingdao, Shandong 266000, China
| | - Lauriane de Fabritus
- Aix-Marseille Universite, CNRS, INSERM, Centre d'Immunologie de Marseille-Luminy (CIML), 13288 Marseille Cedex 9, France
| | - Jinglian Tao
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin 300052, China; Center for Molecular Medicine, Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Essa M Saied
- Institut für Chemie, Humboldt Universität zu Berlin, Berlin 12489, Germany; Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522, Egypt
| | - Ho-Joon Lee
- Department of Genetics, Yale University, New Haven, CT 06520, USA; Center for Genome Analysis, Yale University, New Haven, CT 06510, USA
| | - Bulat R Ramazanov
- Department of Cell Biology, Yale University, New Haven, CT 06520, USA
| | - Benjamin Jackson
- Center for Molecular Medicine, Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Daniel Burkhardt
- Department of Genetics, Yale University, New Haven, CT 06520, USA
| | - Mikhail Parker
- Center for Molecular Medicine, Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Anne S Gleinich
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Zhirui Wang
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Dong Eun Seo
- Center for Molecular Medicine, Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Ting Zhou
- Department of Immunobiology, Yale University, New Haven, CT 06520, USA
| | - Shihao Xu
- NOMIS Center for Immunobiology and Microbial Pathogenesis, the Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Irina Alecu
- Neural Regeneration Laboratory, Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa K1H 8M5, Canada
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Christoph Arenz
- Institut für Chemie, Humboldt Universität zu Berlin, Berlin 12489, Germany
| | - Thorsten Hornemann
- Institute of Clinical Chemistry, University and University Hospital of Zurich, Zurich 8091, Switzerland
| | | | - Serge A van de Pavert
- Aix-Marseille Universite, CNRS, INSERM, Centre d'Immunologie de Marseille-Luminy (CIML), 13288 Marseille Cedex 9, France
| | - Susan M Kaech
- NOMIS Center for Immunobiology and Microbial Pathogenesis, the Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
| | - Natalia B Ivanova
- Center for Molecular Medicine, Department of Genetics, University of Georgia, Athens, GA 30602, USA.
| | - Fabio R Santori
- Department of Immunobiology, Yale University, New Haven, CT 06520, USA.
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8
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Zhang K, Zheng J, Chen Y, Dong J, Li Z, Chiang YP, He M, Huang Q, Tang H, Jiang XC. Inducible phospholipid transfer protein deficiency ameliorates atherosclerosis. Atherosclerosis 2021; 324:9-17. [PMID: 33798923 DOI: 10.1016/j.atherosclerosis.2021.03.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 02/23/2021] [Accepted: 03/11/2021] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND AIMS Atherosclerosis progression and regression studies are related to its prevention and treatment. Although we have gained extensive knowledge on germline phospholipid transfer protein (PLTP) deficiency, the effect of inducible PLTP deficiency in atherosclerosis remains unexplored. METHODS We generated inducible PLTP (iPLTP)-knockout (KO) mice and measured their plasma lipid levels after feeding a normal chow or a Western-type diet. Adenovirus associated virus-proprotein convertase subtilisin/kexin type 9 (AAV-PCSK9) was used to induce hypercholesterolemia in the mice. Collars were placed around the common carotid arteries, and atherosclerosis progression and regression in the carotid arteries and aortic roots were evaluated. RESULTS On a normal chow diet, iPLTP-KO mice exhibited decreased cholesterol, phospholipid, apoA-I, and apoB levels compared with control mice. Furthermore, the overall amount of high-density lipoprotein (HDL) particles was reduced in these mice, but this effect was more profound for larger HDL particles. On a Western-type diet, iPLTP-KO mice again exhibited reduced levels of all tested lipids, even though the basal lipid levels were increased. Additionally, these mice displayed significantly reduced atherosclerotic plaque sizes with increased plaque stability. Importantly, inducible PLTP deficiency significantly ameliorated atherosclerosis by reducing the size of established plaques and the number of macrophages in the plaques without causing lipid accumulation in the liver. CONCLUSIONS Induced PLTP deficiency in adult mice reduces plasma total cholesterol and triglycerides, prevents atherosclerosis progression, and promotes atherosclerosis regression. Thus, PLTP inhibition is a promising therapeutic approach for atherosclerosis.
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Affiliation(s)
- Ke Zhang
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, New York, USA; Department of Emergency, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Jiao Zheng
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, New York, USA; Beijing University of Chinese Medicine, Beijing, China
| | | | | | - Zhiqiang Li
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, New York, USA; Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, Brooklyn, New York, USA
| | - Yeun-Po Chiang
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, New York, USA
| | - Mulin He
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, New York, USA
| | | | | | - Xian-Cheng Jiang
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, New York, USA; Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, Brooklyn, New York, USA.
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9
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Li Z, Chiang YP, He M, Zhang K, Zheng J, Wu W, Cai J, Chen Y, Chen G, Chen Y, Dong J, Worgall TS, Jiang XC. Effect of liver total sphingomyelin synthase deficiency on plasma lipid metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158898. [PMID: 33545384 DOI: 10.1016/j.bbalip.2021.158898] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 01/11/2021] [Accepted: 01/28/2021] [Indexed: 11/26/2022]
Abstract
Sphingomyelin (SM) is one major phospholipids on lipoproteins. It is enriched on apolipoprotein B-containing particles, including very low-density lipoprotein (VLDL) and its catabolites, low-density lipoprotein (LDL). SM is synthesized by sphingomyelin synthase 1 and 2 (SMS1 and SMS2) which utilizes ceramide and phosphatidylcholine, as two substrates, to produce SM and diacylglyceride. SMS1 and SMS2 activities are co-expressed in all tested tissues, including the liver where VLDL is produced. Thus, neither Sms1 gene knockout (KO) nor Sms2 KO approach is sufficient to evaluate the effect of SMS on VLDL metabolism. We prepared liver-specific Sms1 KO/global Sms2 KO mice to evaluate the effect of hepatocyte SM biosynthesis in lipoprotein metabolism. We found that hepatocyte total SMS depletion significantly reduces cellular sphingomyelin levels. Also, we found that the deficiency induces cellular glycosphingolipid levels which is specifically related with SMS1 but not SMS2 deficiency. To our surprise, hepatocyte total SMS deficiency has marginal effect on hepatocyte ceramide, diacylglyceride, and phosphatidylcholine levels. Importantly, total SMS deficiency decreases plasma triglyceride but not apoB levels and reduces larger VLDL concentration. The reduction of triglyceride levels also was observed when the animals were on a high fat diet. Our results show that hepatocyte total SMS blocking can reduce VLDL-triglyceride production and plasma triglyceride levels. This phenomenon could be related with a reduction of atherogenicity.
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Affiliation(s)
- Zhiqiang Li
- Department of Cell Biology, SUNY Downstate Medical Center, United States of America
| | - Yeun-Po Chiang
- Department of Cell Biology, SUNY Downstate Medical Center, United States of America
| | - Mulin He
- Department of Cell Biology, SUNY Downstate Medical Center, United States of America
| | - Ke Zhang
- Department of Cell Biology, SUNY Downstate Medical Center, United States of America
| | - Jiao Zheng
- Department of Cell Biology, SUNY Downstate Medical Center, United States of America
| | - Weihua Wu
- Department of Cell Biology, SUNY Downstate Medical Center, United States of America
| | - Jiajia Cai
- Department of Cell Biology, SUNY Downstate Medical Center, United States of America
| | - Yong Chen
- Department of Cell Biology, SUNY Downstate Medical Center, United States of America
| | - Guangzhi Chen
- Department of Cell Biology, SUNY Downstate Medical Center, United States of America
| | | | | | - Tilla S Worgall
- Department of Medicine, Columbia University, United States of America
| | - Xian-Cheng Jiang
- Department of Cell Biology, SUNY Downstate Medical Center, United States of America; Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, Brooklyn, United States of America.
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10
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Mah M, Febbraio M, Turpin-Nolan S. Circulating Ceramides- Are Origins Important for Sphingolipid Biomarkers and Treatments? Front Endocrinol (Lausanne) 2021; 12:684448. [PMID: 34385976 PMCID: PMC8353232 DOI: 10.3389/fendo.2021.684448] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 06/23/2021] [Indexed: 01/13/2023] Open
Abstract
Biomarkers are important tools for describing the adequacy or inadequacy of biological processes (to allow for the early and accurate diagnosis) and monitoring the biological effects of intervention strategies (to identify and develop optimal dose and treatment strategies). A number of lipid biomarkers are implicated in metabolic disease and the circulating levels of these biomarkers are used in clinical settings to predict and monitor disease severity. There is convincing evidence that specific circulating ceramide species can be used as biological predictors and markers of cardiovascular disease, atherosclerosis and type 2 diabetes mellitus. Here, we review the existing literature that investigated sphingolipids as biomarkers for metabolic disease prediction. What are the advantages and disadvantages? Are circulating ceramides predominantly produced in the liver? Will hepatic sphingolipid inhibitors be able to completely prevent and treat metabolic disease? As sphingolipids are being employed as biomarkers and potential metabolic disease treatments, we explore what is currently known and what still needs to be discovered.
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11
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Kim GT, Kim SJ, Park SH, Lee D, Park TS. Hepatic Expression of the Serine Palmitoyltransferase Subunit Sptlc2 Reduces Lipid Droplets in the Liver by Activating VLDL Secretion. J Lipid Atheroscler 2020; 9:291-303. [PMID: 32821738 PMCID: PMC7379091 DOI: 10.12997/jla.2020.9.2.291] [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: 11/17/2019] [Revised: 02/18/2020] [Accepted: 03/03/2020] [Indexed: 01/22/2023] Open
Abstract
Objective Ceramide is a signaling molecule that contributes to insulin resistance and hepatosteatosis. In the present study, we activated de novo ceramide synthesis by inducing the hepatic expression of Sptlc2 to investigate the role of ceramide in glucose and lipid metabolism. Methods We first constructed an adenovirus containing Sptlc2 (AdSptlc2), which encodes a major catalytic subunit of serine palmitoyltransferase (SPT). We then infected hepatocytes and mice fed a regular diet with AdSptlc2 to activate de novo ceramide biosynthesis. The liver-specific effects of ceramide biosynthesis on glucose and lipid metabolism were investigated by measuring changes in insulin signaling, lipid droplet formation, and very low-density lipoprotein (VLDL) secretion. Results In HepG2 hepatocytes, adenoviral Sptlc2 expression inhibited insulin signaling and increased ceramide levels via activation of c-Jun N-terminal kinase and serine phosphorylation of insulin receptor substrate 1. In contrast, in mice, AdSptlc2 infection decreased plasma glucose levels by downregulating gluconeogenic genes and increased plasma triglyceride levels by increasing VLDL secretion. In mice infected with AdSptlc2, glucose intolerance and insulin sensitivity improved, while pyruvate utilization via gluconeogenesis decreased. Conclusion Hepatic ceramide was found to modulate hepatosteatosis and the insulin response via increased VLDL secretion and inhibition of gluconeogenesis in vivo. Although inhibition of the insulin response was observed in vitro, the compensatory mechanism of relieving ceramide-induced stress and reducing ceramide levels resulted in improvements of glucose and lipid metabolic profiles in vivo. This discrepancy between in vitro and in vivo regulation mechanisms suggests that ceramide plays a role in non-alcoholic fatty liver disease and insulin resistance.
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Affiliation(s)
- Goon-Tae Kim
- Department of Life Science, Gachon University, Seongnam, Korea
| | - Su-Jung Kim
- Biomedical Research Center, Asan Institute for Life Sciences, Seoul, Korea
| | - Si-Hyun Park
- Department of Life Science, Gachon University, Seongnam, Korea
| | - Dongyup Lee
- Department of Life Science, Gachon University, Seongnam, Korea
| | - Tae-Sik Park
- Department of Life Science, Gachon University, Seongnam, Korea
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12
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Tremblay BL, Guénard F, Lamarche B, Pérusse L, Vohl MC. Integrative Network Analysis of Multi-Omics Data in the Link between Plasma Carotenoid Concentrations and Lipid Profile. Lifestyle Genom 2019; 13:11-19. [PMID: 31770753 DOI: 10.1159/000503828] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 09/24/2019] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Carotenoids, which are a reliable biomarker of fruit and vegetable consumption, are positively associated with the lipid profile. Circulating carotenoid concentrations may interact with several omics profiles including genome, transcriptome, and epigenome. Few studies have used multi-omics approaches, and they rarely include environmental factors, such as diet. OBJECTIVE The objective of this observational study was to examine the potential role of multi-omics data in the interconnection between diet, represented by total carotenoids, and lipid profile using weighted gene correlation network analysis (WGCNA). METHODS Blood leukocyte DNA methylation levels of 472,245 CpG sites and whole blood gene expression levels of 18,160 transcripts were tested for associations with total carotenoid concentrations using regressions in 48 healthy subjects. WGCNA was used to identify co-omics modules and hub genes related to the lipid profile. RESULTS Among genes associated with total carotenoid concentrations, a total of 236 genes were identified at both DNA methylation and gene expression levels. Using WGCNA, six modules, consisting of groups of highly correlated genes represented by colors, were identified and linked to the lipid profile. Probes clustered in the turquoise and green modules correlated with plasma lipid concentrations. A total of 28 hub genes were identified. CONCLUSIONS Genome-wide DNA methylation and gene expression levels were both associated with plasma total carotenoid concentrations. Several hub genes, mostly involved in lipid metabolism and inflammatory response with several genetic variants associated with plasma lipid concentrations, came out of the integrative analysis. This provides a comprehensive understanding of the interactive molecular system between carotenoids, omics, and plasma lipid profile.
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Affiliation(s)
- Bénédicte L Tremblay
- Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, Québec, Canada.,School of Nutrition, Laval University, Quebec City, Québec, Canada
| | - Frédéric Guénard
- Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, Québec, Canada.,School of Nutrition, Laval University, Quebec City, Québec, Canada
| | - Benoît Lamarche
- Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, Québec, Canada.,School of Nutrition, Laval University, Quebec City, Québec, Canada
| | - Louis Pérusse
- Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, Québec, Canada.,Department of Kinesiology, Laval University, Quebec City, Québec, Canada
| | - Marie-Claude Vohl
- Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, Québec, Canada, .,School of Nutrition, Laval University, Quebec City, Québec, Canada,
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13
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Wu J, Ma S, Sandhoff R, Ming Y, Hotz-Wagenblatt A, Timmerman V, Bonello-Palot N, Schlotter-Weigel B, Auer-Grumbach M, Seeman P, Löscher WN, Reindl M, Weiss F, Mah E, Weisshaar N, Madi A, Mohr K, Schlimbach T, Velasco Cárdenas RMH, Koeppel J, Grünschläger F, Müller L, Baumeister M, Brügger B, Schmitt M, Wabnitz G, Samstag Y, Cui G. Loss of Neurological Disease HSAN-I-Associated Gene SPTLC2 Impairs CD8 + T Cell Responses to Infection by Inhibiting T Cell Metabolic Fitness. Immunity 2019; 50:1218-1231.e5. [PMID: 30952607 DOI: 10.1016/j.immuni.2019.03.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 01/07/2019] [Accepted: 03/06/2019] [Indexed: 12/16/2022]
Abstract
Patients with the neurological disorder HSAN-I suffer frequent infections, attributed to a lack of pain sensation and failure to seek care for minor injuries. Whether protective CD8+ T cells are affected in HSAN-I patients remains unknown. Here, we report that HSAN-I-associated mutations in serine palmitoyltransferase subunit SPTLC2 dampened human T cell responses. Antigen stimulation and inflammation induced SPTLC2 expression, and murine T-cell-specific ablation of Sptlc2 impaired antiviral-T-cell expansion and effector function. Sptlc2 deficiency reduced sphingolipid biosynthetic flux and led to prolonged activation of the mechanistic target of rapamycin complex 1 (mTORC1), endoplasmic reticulum (ER) stress, and CD8+ T cell death. Protective CD8+ T cell responses in HSAN-I patient PBMCs and Sptlc2-deficient mice were restored by supplementing with sphingolipids and pharmacologically inhibiting ER stress-induced cell death. Therefore, SPTLC2 underpins protective immunity by translating extracellular stimuli into intracellular anabolic signals and antagonizes ER stress to promote T cell metabolic fitness.
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Affiliation(s)
- Jingxia Wu
- T Cell Metabolism Group (D140), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Sicong Ma
- T Cell Metabolism Group (D140), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Medical Faculty Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
| | - Roger Sandhoff
- Lipid Pathobiochemistry Group (G131), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Yanan Ming
- Internal Medicine IV, University Heidelberg Hospital, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany
| | - Agnes Hotz-Wagenblatt
- Core Facility Omics IT and Data Management, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Vincent Timmerman
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences, Institute Born Bunge, B-2610, University of Antwerp, Antwerpen, Belgium
| | - Nathalie Bonello-Palot
- Department of Medical Genetics, Children Timone Hospital, 264 Rue Saint Pierre & Aix Marseille University, INSERM, MMG, U1251, 13385 Marseille, France
| | - Beate Schlotter-Weigel
- Friedrich-Baur-Institut, Neurologische Klinik and Poliklinik Ludwig-Maximilians-Universität, 80336 München, Germany
| | - Michaela Auer-Grumbach
- Department of Orthopaedics and Trauma Surgery, Medical University of Vienna, Vienna, Austria
| | - Pavel Seeman
- DNA Laboratory, Department of Child Neurology, 2nd Medical School, University Hospital Motol, Charles University, Prague, Czech Republic
| | - Wolfgang N Löscher
- Clinical Department of Neurology, Medical University Innsbruck, Anichstr. 35, 6020 Innsbruck, Austria
| | - Markus Reindl
- Clinical Department of Neurology, Medical University Innsbruck, Anichstr. 35, 6020 Innsbruck, Austria
| | - Florian Weiss
- Department of Psychiatry and Psychotherapy, University Hospital of Psychiatry, Bolligenstrasse 111, 3000 Bern, Germany
| | - Eric Mah
- School of Medicine, UC San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Nina Weisshaar
- T Cell Metabolism Group (D140), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Faculty of Biosciences, Heidelberg University, 69120 Heidelberg, Germany
| | - Alaa Madi
- T Cell Metabolism Group (D140), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Faculty of Biosciences, Heidelberg University, 69120 Heidelberg, Germany
| | - Kerstin Mohr
- T Cell Metabolism Group (D140), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Tilo Schlimbach
- T Cell Metabolism Group (D140), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Rubí M-H Velasco Cárdenas
- T Cell Metabolism Group (D140), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Jonas Koeppel
- T Cell Metabolism Group (D140), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Florian Grünschläger
- T Cell Metabolism Group (D140), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Lisann Müller
- T Cell Metabolism Group (D140), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Maren Baumeister
- T Cell Metabolism Group (D140), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Britta Brügger
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany
| | - Michael Schmitt
- Internal Medicine V, University Heidelberg Hospital, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Guido Wabnitz
- Section Molecular Immunology, Institute of Immunology, Heidelberg University, Im Neuenheimer Feld 305, 69120 Heidelberg, Germany
| | - Yvonne Samstag
- Section Molecular Immunology, Institute of Immunology, Heidelberg University, Im Neuenheimer Feld 305, 69120 Heidelberg, Germany
| | - Guoliang Cui
- T Cell Metabolism Group (D140), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Faculty of Biosciences, Heidelberg University, 69120 Heidelberg, Germany.
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14
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Li Z, Kabir I, Tietelman G, Huan C, Fan J, Worgall T, Jiang XC. Sphingolipid de novo biosynthesis is essential for intestine cell survival and barrier function. Cell Death Dis 2018; 9:173. [PMID: 29415989 PMCID: PMC5833386 DOI: 10.1038/s41419-017-0214-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 11/13/2017] [Accepted: 12/07/2017] [Indexed: 12/15/2022]
Abstract
Serine palmitoyltransferase (SPT) is the rate-limiting enzyme for sphingolipid biosynthesis. SPT has two major subunits, SPTLC1 and SPTLC2. We previously found that liver Sptlc2 deficiency in early life impairs the development of adherens junctions. Here, we investigated the role of Sptlc2 deficiency in intestine. We treated Sptlc2-Flox/villin-Cre-ERT2 mice with tamoxifen (days 1, 2, and 3) to ablate Sptlc2 specifically in the intestine. At day 6 after tamoxifen treatment, Sptlc2-deficient mice had significantly decreased body weight with concurrent diarrhea and rectal bleeding. The number of goblet cells was reduced in both large and small intestine of Sptlc2-deficient mice compared with controls. Sptlc2 deficiency suppressed the level of mucin2 in the colon and increased circulating lipopolysaccharides, suggesting that SPT activity has a housekeeping function in the intestine. All Sptlc2-deficient mice died 7-10 days after tamoxifen treatment. Notably, supplementation with antibiotics and dexamethasone reduced lethality by 70%. We also found that colon specimens from patients with inflammatory bowel diseases had significantly reduced Sptlc2 expression, SPTLC2 staining, and goblet cell numbers. SPT activity is crucial for intestinal cell survival and barrier function.
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Affiliation(s)
- Zhiqiang Li
- Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn, NY, 11203, USA
- Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, Brooklyn, NY, 11209, USA
| | - Inamul Kabir
- Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn, NY, 11203, USA
| | - Gladys Tietelman
- Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn, NY, 11203, USA
| | - Chongmin Huan
- Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn, NY, 11203, USA
| | - Jianglin Fan
- Department of Molecular Pathology, University of Yamanashi, Yamanashi, Japan
| | - Tilla Worgall
- Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - Xian-Cheng Jiang
- Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn, NY, 11203, USA.
- Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, Brooklyn, NY, 11209, USA.
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15
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Flotte TR, Daniels E, Benson J, Bevett-Rose JM, Cornetta K, Diggins M, Johnston J, Sepelak S, van der Loo JCM, Wilson JM, McDonald CL. The Gene Therapy Resource Program: A Decade of Dedication to Translational Research by the National Heart, Lung, and Blood Institute. HUM GENE THER CL DEV 2017; 28:178-186. [PMID: 29130351 PMCID: PMC5733658 DOI: 10.1089/humc.2017.170] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 09/26/2017] [Indexed: 12/11/2022] Open
Abstract
Over a 10-year period, the Gene Therapy Resource Program (GTRP) of the National Heart Lung and Blood Institute has provided a set of core services to investigators to facilitate the clinical translation of gene therapy. These services have included a preclinical (research-grade) vector production core; current Good Manufacturing Practice clinical-grade vector cores for recombinant adeno-associated virus and lentivirus vectors; a pharmacology and toxicology core; and a coordinating center to manage program logistics and to provide regulatory and financial support to early-phase clinical trials. In addition, the GTRP has utilized a Steering Committee and a Scientific Review Board to guide overall progress and effectiveness and to evaluate individual proposals. These resources have been deployed to assist 82 investigators with 172 approved service proposals. These efforts have assisted in clinical trial implementation across a wide range of genetic, cardiac, pulmonary, and blood diseases. Program outcomes and potential future directions of the program are discussed.
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Affiliation(s)
- Terence R. Flotte
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Eric Daniels
- Social and Scientific Systems, Inc., Silver Spring, Maryland
| | - Janet Benson
- Lovelace Biomedical and Environmental Research Institute, Albuquerque, New Mexico
| | | | - Kenneth Cornetta
- Department of Medical and Molecular Genetics, Indiana University, Indianapolis, Indiana
| | | | - Julie Johnston
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Susan Sepelak
- Social and Scientific Systems, Inc., Silver Spring, Maryland
| | - Johannes C. M. van der Loo
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - James M. Wilson
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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16
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Sankella S, Garg A, Agarwal AK. Activation of Sphingolipid Pathway in the Livers of Lipodystrophic Agpat2-/- Mice. J Endocr Soc 2017; 1:980-993. [PMID: 29264548 PMCID: PMC5686665 DOI: 10.1210/js.2017-00157] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 05/15/2017] [Indexed: 12/26/2022] Open
Abstract
A several fold increase in triacylglycerol is observed in the livers of lipodystrophic Agpat2−/− mice. We have previously reported an unexpected increase in the phosphatidic acid (PA) levels in the livers of these mice and that a few specific molecular species of PA were able to transcriptionally upregulate hepatic gluconeogenesis. In the current study, we measured the metabolites and expression of associated enzymes of the sphingolipid synthesis pathway. The entire sphingolipid pathway was activated both at the gene expression and the metabolite level. The levels of some ceramides were increased by as much as ~eightfold in the livers of Agpat2−/− mice. Furthermore, several molecular species of ceramides were increased in the plasma of Agpat2−/− mice, specifically ceramide C16:0, which was threefold elevated in the plasma of both the sexes. However, the ceramides failed to increase glucose production in mouse primary hepatocytes obtained from wild-type and Agpat2−/− mice, further establishing the specificity of PA in the induction of hepatic gluconeogenesis. This study shows elevated levels of sphingolipids in the steatotic livers of Agpat2−/− mice and increased expression of associated enzymes for the sphingolipid pathway. Therefore, this study and those in the literature suggest that ceramide C16:0 could be used as a biomarker for insulin resistance/type 2 diabetes mellitus.
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Affiliation(s)
- Shireesha Sankella
- Division of Nutrition and Metabolic Diseases, University of Texas Southwestern Medical Center, Dallas, Texas 75390.,Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Abhimanyu Garg
- Division of Nutrition and Metabolic Diseases, University of Texas Southwestern Medical Center, Dallas, Texas 75390.,Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Anil K Agarwal
- Division of Nutrition and Metabolic Diseases, University of Texas Southwestern Medical Center, Dallas, Texas 75390.,Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, Texas 75390
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17
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Alexaki A, Clarke BA, Gavrilova O, Ma Y, Zhu H, Ma X, Xu L, Tuymetova G, Larman BC, Allende ML, Dunn TM, Proia RL. De Novo Sphingolipid Biosynthesis Is Required for Adipocyte Survival and Metabolic Homeostasis. J Biol Chem 2017; 292:3929-3939. [PMID: 28100772 DOI: 10.1074/jbc.m116.756460] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 01/18/2017] [Indexed: 12/18/2022] Open
Abstract
Sphingolipids are a diverse class of essential cellular lipids that function as structural membrane components and as signaling molecules. Cells acquire sphingolipids by both de novo biosynthesis and recycling of exogenous sphingolipids. The individual importance of these pathways for the generation of essential sphingolipids in differentiated cells is not well understood. To investigate the requirement for de novo sphingolipid biosynthesis in adipocytes, a cell type with highly regulated lipid metabolism, we generated mice with an adipocyte-specific deletion of Sptlc1 Sptlc1 is an obligate subunit of serine palmitoyltransferase, the enzyme responsible for the first and rate-limiting step of de novo sphingolipid biosynthesis. These mice, which initially developed adipose tissue, exhibited a striking age-dependent loss of adipose tissue accompanied by evidence of adipocyte death, increased macrophage infiltration, and tissue fibrosis. Adipocyte differentiation was not affected by the Sptlc1 deletion. The mice also had elevated fasting blood glucose, fatty liver, and insulin resistance. Collectively, these data indicate that de novo sphingolipid biosynthesis is required for adipocyte cell viability and normal metabolic function and that reduced de novo sphingolipid biosynthesis within adipocytes is associated with adipocyte death, adipose tissue remodeling, and metabolic dysfunction.
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Affiliation(s)
| | | | - Oksana Gavrilova
- Mouse Metabolism Core Laboratory, NIDDK, National Institutes of Health, Bethesda, Maryland 20892 and
| | - Yinyan Ma
- Mouse Metabolism Core Laboratory, NIDDK, National Institutes of Health, Bethesda, Maryland 20892 and
| | - Hongling Zhu
- From the Genetics of Development and Disease Branch and
| | - Xinran Ma
- From the Genetics of Development and Disease Branch and
| | - Lingyan Xu
- From the Genetics of Development and Disease Branch and
| | | | | | | | - Teresa M Dunn
- the Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20184
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18
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Li Z, Kabir I, Jiang H, Zhou H, Libien J, Zeng J, Stanek A, Ou P, Li KR, Zhang S, Bui HH, Kuo MS, Park TS, Kim B, Worgall TS, Huan C, Jiang XC. Liver serine palmitoyltransferase activity deficiency in early life impairs adherens junctions and promotes tumorigenesis. Hepatology 2016; 64:2089-2102. [PMID: 27642075 PMCID: PMC5115983 DOI: 10.1002/hep.28845] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 08/18/2016] [Accepted: 09/08/2016] [Indexed: 12/22/2022]
Abstract
UNLABELLED Serine palmitoyltransferase is the key enzyme in sphingolipid biosynthesis. Mice lacking serine palmitoyltransferase are embryonic lethal. We prepared liver-specific mice deficient in the serine palmitoyltransferase long chain base subunit 2 gene using an albumin-cyclization recombination approach and found that the deficient mice have severe jaundice. Moreover, the deficiency impairs hepatocyte polarity, attenuates liver regeneration after hepatectomy, and promotes tumorigenesis. Importantly, we show that the deficiency significantly reduces sphingomyelin but not other sphingolipids in hepatocyte plasma membrane; greatly reduces cadherin, the major protein in adherens junctions, on the membrane; and greatly induces cadherin phosphorylation, an indication of its degradation. The deficiency affects cellular distribution of β-catenin, the central component of the canonical Wnt pathway. Furthermore, such a defect can be partially corrected by sphingomyelin supplementation in vivo and in vitro. CONCLUSION The plasma membrane sphingomyelin level is one of the key factors in regulating hepatocyte polarity and tumorigenesis. (Hepatology 2016;64:2089-2102).
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Affiliation(s)
- Zhiqiang Li
- Department of Cell Biology, Department of Surgery, and Department of Pathology, SUNY Downstate Medical Center,Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, Brooklyn
| | - Inamul Kabir
- Department of Cell Biology, Department of Surgery, and Department of Pathology, SUNY Downstate Medical Center
| | - Hui Jiang
- Department of Cell Biology, Department of Surgery, and Department of Pathology, SUNY Downstate Medical Center
| | | | - Jenny Libien
- Department of Cell Biology, Department of Surgery, and Department of Pathology, SUNY Downstate Medical Center
| | - Jianying Zeng
- Department of Cell Biology, Department of Surgery, and Department of Pathology, SUNY Downstate Medical Center
| | - Albert Stanek
- Department of Cell Biology, Department of Surgery, and Department of Pathology, SUNY Downstate Medical Center
| | - Peiqi Ou
- Department of Cell Biology, Department of Surgery, and Department of Pathology, SUNY Downstate Medical Center
| | - Kailyn R. Li
- Department of Cell Biology, Department of Surgery, and Department of Pathology, SUNY Downstate Medical Center
| | - Shane Zhang
- Department of Cell Biology, Department of Surgery, and Department of Pathology, SUNY Downstate Medical Center
| | - Hai H. Bui
- Lilly Research Laboratories, Eli Lilly & Company, Indianapolis, IN, 46285
| | - Ming-Shang Kuo
- Lilly Research Laboratories, Eli Lilly & Company, Indianapolis, IN, 46285
| | - Tae-Sik Park
- Department of Life Science, Gachon University, Sungnam, South Korea
| | | | | | - Chongmin Huan
- Department of Cell Biology, Department of Surgery, and Department of Pathology, SUNY Downstate Medical Center,Correspondence: ; Or
| | - Xian-Cheng Jiang
- Department of Cell Biology, Department of Surgery, and Department of Pathology, SUNY Downstate Medical Center,Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, Brooklyn,Correspondence: ; Or
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19
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Genin MJ, Gonzalez Valcarcel IC, Holloway WG, Lamar J, Mosior M, Hawkins E, Estridge T, Weidner J, Seng T, Yurek D, Adams LA, Weller J, Reynolds VL, Brozinick JT. Imidazopyridine and Pyrazolopiperidine Derivatives as Novel Inhibitors of Serine Palmitoyl Transferase. J Med Chem 2016; 59:5904-10. [PMID: 27213958 DOI: 10.1021/acs.jmedchem.5b01851] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
To develop novel treatments for type 2 diabetes and dyslipidemia, we pursued inhibitors of serine palmitoyl transferase (SPT). To this end compounds 1 and 2 were developed as potent SPT inhibitors in vitro. 1 and 2 reduce plasma ceramides in rodents, have a slight trend toward enhanced insulin sensitization in DIO mice, and reduce triglycerides and raise HDL in cholesterol/cholic acid fed rats. Unfortunately these molecules cause a gastric enteropathy after chronic dosing in rats.
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Affiliation(s)
- Michael J Genin
- Discovery Chemistry Research and Technology, ‡Cardiovascular and Metabolic Diseases Therapeutic Area, §Diabetes Therapeutic Area, ∥Drug Disposition and Metabolism, ⊥Quantitative Biology, and #Non-Clinical Safety, Lilly Research Laboratories, a Division of Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Isabel C Gonzalez Valcarcel
- Discovery Chemistry Research and Technology, ‡Cardiovascular and Metabolic Diseases Therapeutic Area, §Diabetes Therapeutic Area, ∥Drug Disposition and Metabolism, ⊥Quantitative Biology, and #Non-Clinical Safety, Lilly Research Laboratories, a Division of Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - William G Holloway
- Discovery Chemistry Research and Technology, ‡Cardiovascular and Metabolic Diseases Therapeutic Area, §Diabetes Therapeutic Area, ∥Drug Disposition and Metabolism, ⊥Quantitative Biology, and #Non-Clinical Safety, Lilly Research Laboratories, a Division of Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Jason Lamar
- Discovery Chemistry Research and Technology, ‡Cardiovascular and Metabolic Diseases Therapeutic Area, §Diabetes Therapeutic Area, ∥Drug Disposition and Metabolism, ⊥Quantitative Biology, and #Non-Clinical Safety, Lilly Research Laboratories, a Division of Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Marian Mosior
- Discovery Chemistry Research and Technology, ‡Cardiovascular and Metabolic Diseases Therapeutic Area, §Diabetes Therapeutic Area, ∥Drug Disposition and Metabolism, ⊥Quantitative Biology, and #Non-Clinical Safety, Lilly Research Laboratories, a Division of Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Eric Hawkins
- Discovery Chemistry Research and Technology, ‡Cardiovascular and Metabolic Diseases Therapeutic Area, §Diabetes Therapeutic Area, ∥Drug Disposition and Metabolism, ⊥Quantitative Biology, and #Non-Clinical Safety, Lilly Research Laboratories, a Division of Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Thomas Estridge
- Discovery Chemistry Research and Technology, ‡Cardiovascular and Metabolic Diseases Therapeutic Area, §Diabetes Therapeutic Area, ∥Drug Disposition and Metabolism, ⊥Quantitative Biology, and #Non-Clinical Safety, Lilly Research Laboratories, a Division of Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Jeffrey Weidner
- Discovery Chemistry Research and Technology, ‡Cardiovascular and Metabolic Diseases Therapeutic Area, §Diabetes Therapeutic Area, ∥Drug Disposition and Metabolism, ⊥Quantitative Biology, and #Non-Clinical Safety, Lilly Research Laboratories, a Division of Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Thomas Seng
- Discovery Chemistry Research and Technology, ‡Cardiovascular and Metabolic Diseases Therapeutic Area, §Diabetes Therapeutic Area, ∥Drug Disposition and Metabolism, ⊥Quantitative Biology, and #Non-Clinical Safety, Lilly Research Laboratories, a Division of Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - David Yurek
- Discovery Chemistry Research and Technology, ‡Cardiovascular and Metabolic Diseases Therapeutic Area, §Diabetes Therapeutic Area, ∥Drug Disposition and Metabolism, ⊥Quantitative Biology, and #Non-Clinical Safety, Lilly Research Laboratories, a Division of Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Lisa A Adams
- Discovery Chemistry Research and Technology, ‡Cardiovascular and Metabolic Diseases Therapeutic Area, §Diabetes Therapeutic Area, ∥Drug Disposition and Metabolism, ⊥Quantitative Biology, and #Non-Clinical Safety, Lilly Research Laboratories, a Division of Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Jennifer Weller
- Discovery Chemistry Research and Technology, ‡Cardiovascular and Metabolic Diseases Therapeutic Area, §Diabetes Therapeutic Area, ∥Drug Disposition and Metabolism, ⊥Quantitative Biology, and #Non-Clinical Safety, Lilly Research Laboratories, a Division of Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Vincent L Reynolds
- Discovery Chemistry Research and Technology, ‡Cardiovascular and Metabolic Diseases Therapeutic Area, §Diabetes Therapeutic Area, ∥Drug Disposition and Metabolism, ⊥Quantitative Biology, and #Non-Clinical Safety, Lilly Research Laboratories, a Division of Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Joseph T Brozinick
- Discovery Chemistry Research and Technology, ‡Cardiovascular and Metabolic Diseases Therapeutic Area, §Diabetes Therapeutic Area, ∥Drug Disposition and Metabolism, ⊥Quantitative Biology, and #Non-Clinical Safety, Lilly Research Laboratories, a Division of Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
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20
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Kusminski CM, Chen S, Ye R, Sun K, Wang QA, Spurgin SB, Sanders PE, Brozinick JT, Geldenhuys WJ, Li WH, Unger RH, Scherer PE. MitoNEET-Parkin Effects in Pancreatic α- and β-Cells, Cellular Survival, and Intrainsular Cross Talk. Diabetes 2016; 65:1534-55. [PMID: 26895793 PMCID: PMC5310214 DOI: 10.2337/db15-1323] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 02/06/2016] [Indexed: 12/16/2022]
Abstract
Mitochondrial metabolism plays an integral role in glucose-stimulated insulin secretion (GSIS) in β-cells. In addition, the diabetogenic role of glucagon released from α-cells plays a major role in the etiology of both type 1 and type 2 diabetes because unopposed hyperglucagonemia is a pertinent contributor to diabetic hyperglycemia. Titrating expression levels of the mitochondrial protein mitoNEET is a powerful approach to fine-tune mitochondrial capacity of cells. Mechanistically, β-cell-specific mitoNEET induction causes hyperglycemia and glucose intolerance due to activation of a Parkin-dependent mitophagic pathway, leading to the formation of vacuoles and uniquely structured mitophagosomes. Induction of mitoNEET in α-cells leads to fasting-induced hypoglycemia and hypersecretion of insulin during GSIS. MitoNEET-challenged α-cells exert potent antiapoptotic effects on β-cells and prevent cellular dysfunction associated with mitoNEET overexpression in β-cells. These observations identify that reduced mitochondrial function in α-cells exerts potently protective effects on β-cells, preserving β-cell viability and mass.
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Affiliation(s)
- Christine M Kusminski
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Shiuhwei Chen
- Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, TX Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Risheng Ye
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Kai Sun
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Qiong A Wang
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Stephen B Spurgin
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Phillip E Sanders
- Lilly Research Laboratories, Division of Eli Lilly and Co., Indianapolis, IN
| | - Joseph T Brozinick
- Lilly Research Laboratories, Division of Eli Lilly and Co., Indianapolis, IN
| | - Werner J Geldenhuys
- Department of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV
| | - Wen-Hong Li
- Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, TX Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Roger H Unger
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, TX
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21
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Camell CD, Nguyen KY, Jurczak MJ, Christian BE, Shulman GI, Shadel GS, Dixit VD. Macrophage-specific de Novo Synthesis of Ceramide Is Dispensable for Inflammasome-driven Inflammation and Insulin Resistance in Obesity. J Biol Chem 2015; 290:29402-13. [PMID: 26438821 DOI: 10.1074/jbc.m115.680199] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Indexed: 12/31/2022] Open
Abstract
Dietary lipid overload and calorie excess during obesity is a low grade chronic inflammatory state with diminished ability to appropriately metabolize glucose or lipids. Macrophages are critical in maintaining adipose tissue homeostasis, in part by regulating lipid metabolism, energy homeostasis, and tissue remodeling. During high fat diet-induced obesity, macrophages are activated by lipid derived "danger signals" such as ceramides and palmitate and promote the adipose tissue inflammation in an Nlrp3 inflammasome-dependent manner. Given that the metabolic fate of fatty acids in macrophages is not entirely elucidated, we have hypothesized that de novo synthesis of ceramide, through the rate-limiting enzyme serine palmitoyltransferase long chain (Sptlc)-2, is required for saturated fatty acid-driven Nlrp3 inflammasome activation in macrophages. Here we report that mitochondrial targeted overexpression of catalase, which is established to mitigate oxidative stress, controls ceramide-induced Nlrp3 inflammasome activation but does not affect the ATP-mediated caspase-1 cleavage. Surprisingly, myeloid cell-specific deletion of Sptlc2 is not required for palmitate-driven Nlrp3 inflammasome activation. Furthermore, the ablation of Sptlc2 in macrophages did not impact macrophage polarization or obesity-induced adipose tissue leukocytosis. Consistent with these data, investigation of insulin resistance using hyperinsulinemic-euglycemic clamps revealed no significant differences in obese mice lacking ceramide de novo synthesis machinery in macrophages. These data suggest that alternate metabolic pathways control fatty acid-derived ceramide synthesis in macrophage and the Nlrp3 inflammasome activation in obesity.
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Affiliation(s)
- Christina D Camell
- From the Section of Comparative Medicine and Department of Immunobiology
| | - Kim Y Nguyen
- From the Section of Comparative Medicine and Department of Immunobiology
| | | | | | | | - Gerald S Shadel
- Departments of Internal Medicine, Genetics, Yale School of Medicine, New Haven, Connectitcut 06520
| | - Vishwa Deep Dixit
- From the Section of Comparative Medicine and Department of Immunobiology,
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22
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Ding T, Kabir I, Li Y, Lou C, Yazdanyar A, Xu J, Dong J, Zhou H, Park T, Boutjdir M, Li Z, Jiang XC. All members in the sphingomyelin synthase gene family have ceramide phosphoethanolamine synthase activity. J Lipid Res 2015; 56:537-545. [PMID: 25605874 DOI: 10.1194/jlr.m054627] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sphingomyelin synthase-related protein (SMSr) synthesizes the sphingomyelin analog ceramide phosphoethanolamine (CPE) in cells. Previous cell studies indicated that SMSr is involved in ceramide homeostasis and is crucial for cell function. To further examine SMSr function in vivo, we generated Smsr KO mice that were fertile and had no obvious phenotypic alterations. Quantitative MS analyses of plasma, liver, and macrophages from the KO mice revealed only marginal changes in CPE and ceramide as well as other sphingolipid levels. Because SMS2 also has CPE synthase activity, we prepared Smsr/Sms2 double KO mice. We found that CPE levels were not significantly changed in macrophages, suggesting that CPE levels are not exclusively dependent on SMSr and SMS2 activities. We then measured CPE levels in Sms1 KO mice and found that Sms1 deficiency also reduced plasma CPE levels. Importantly, we found that expression of Sms1 or Sms2 in SF9 insect cells significantly increased not only SM but also CPE formation, indicating that SMS1 also has CPE synthase activity. Moreover, we measured CPE synthase Km and Vmax for SMS1, SMS2, and SMSr using different NBD ceramides. Our study reveals that all mouse SMS family members (SMSr, SMS1, and SMS2) have CPE synthase activity. However, neither CPE nor SMSr appears to be a critical regulator of ceramide levels in vivo.
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Affiliation(s)
- Tingbo Ding
- School of Pharmacy, Fudan University, China; Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY
| | - Inamul Kabir
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY
| | - Yue Li
- School of Pharmacy, Fudan University, China; Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY
| | - Caixia Lou
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY; Guangdong Medical Laboratory Animal Center, Foshan, China
| | | | - Jiachen Xu
- School of Pharmacy, Fudan University, China
| | - Jibin Dong
- School of Pharmacy, Fudan University, China
| | - Hongwen Zhou
- Department of Endocrinology, The First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Taesik Park
- Department of Life Science, Gachon University, Sungnam, 461-701, South Korea
| | | | - Zhiqiang Li
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY
| | - Xian-Cheng Jiang
- School of Pharmacy, Fudan University, China; Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY; Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, Brooklyn, NY.
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23
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Allende ML, Proia RL. Simplifying complexity: genetically resculpting glycosphingolipid synthesis pathways in mice to reveal function. Glycoconj J 2014; 31:613-22. [PMID: 25351657 PMCID: PMC4245496 DOI: 10.1007/s10719-014-9563-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 10/03/2014] [Indexed: 11/30/2022]
Abstract
Glycosphingolipids (GSLs) are a group of plasma-membrane lipids notable for their extremely diverse glycan head groups. The metabolic pathways for GSLs, including the identity of the biosynthetic enzymes needed for synthesis of their glycans, are now well understood. Many of their cellular functions, which include plasma-membrane organization, regulation of cell signaling, endocytosis, and serving as binding sites for pathogens and endogenous receptors, have also been established. However, an understanding of their functions in vivo had been lagging. Studies employing genetic manipulations of the GSL synthesis pathways in mice have been used to systematically reduce the large numbers and complexity of GSL glycan structures, allowing the in vivo functions of GSLs to be revealed from analysis of the resulting phenotypes. Findings from these studies have produced a clearer picture of the role of GSLs in mammalian physiology, which is the topic of this review.
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Affiliation(s)
- Maria Laura Allende
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 10, Room 9D-06; 10 Center DR MSC 1821, Bethesda, MD, 20892-1821, USA
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24
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Chen C, Yang B, Zeng Z, Yang H, Liu C, Ren J, Huang L. Genetic dissection of blood lipid traits by integrating genome-wide association study and gene expression profiling in a porcine model. BMC Genomics 2013; 14:848. [PMID: 24299188 PMCID: PMC4046658 DOI: 10.1186/1471-2164-14-848] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 11/19/2013] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Serum concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) are highly heritable traits that are used clinically to evaluate risk for cardiovascular disease in humans. In this study, we applied a genome-wide association study (GWAS) in 1,075 pigs from two populations and gene expression studies on 497 liver samples to dissect the genetic basis of serum lipids in a pig model. RESULTS We totally identified 8, 5, 2 and 3 genomic loci harboring 109 SNPs that were significantly associated with LDL-C, TC, TG and the ratio of HDL-C/LDL-C in two experimental populations, respectively. In the F2 population, the most prominent SNP was identified at the SSC3: 124,769,847 bp where APOB is the well-known candidate gene. However, in the Sutai population, the most number of significant SNPs was identified at SSC2: 64.97-82.22 Mb where LDLR was identified as the candidate gene. Furthermore, we firstly reported 4 novel genomic loci in pigs harboring the LDL-C-associated SNPs. We also observed obvious population heterogeneity in the two tested populations. Through whole-genome gene expression analysis, we detected 718 trait-correlated expressions. Many of these transcripts correspond to candidate genes for blood lipids in humans. The GWAS mapped 120 cis-eQTLs and 523 trans-eQTLs for these transcripts. One gene encoding the transcript gnl|UG|Ssc#S35330332 stands out to be an important candidate gene for LDL-C by an integrative analysis of GWAS, eQTL and trait-associated expression. CONCLUSIONS We identified the genomic regions or candidate genes associated with blood lipids by an integrative analysis of GWAS, QTT and eQTL mapping in pigs. The findings would benefit the further identification of the causative genes for blood lipid traits in both pigs and humans.
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Affiliation(s)
- Congying Chen
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China
| | - Bin Yang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China
| | - Zhijun Zeng
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China
| | - Hui Yang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China
| | - Chenlong Liu
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China
| | - Jun Ren
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China
| | - Lusheng Huang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China
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25
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Brozinick JT, Hawkins E, Hoang Bui H, Kuo MS, Tan B, Kievit P, Grove K. Plasma sphingolipids are biomarkers of metabolic syndrome in non-human primates maintained on a Western-style diet. Int J Obes (Lond) 2013; 37:1064-70. [PMID: 23207405 PMCID: PMC3718866 DOI: 10.1038/ijo.2012.191] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 10/09/2012] [Accepted: 10/16/2012] [Indexed: 12/18/2022]
Abstract
BACKGROUND The intake of a Western diet enriched in animal fat has been shown to be a major risk factor for Type 2 diabetes and obesity. Previous rodent studies have indicated that these conditions may be triggered by the accumulation of the sphingolipid ceramide in insulin-sensitive tissues. However, data are lacking in this regard from both humans and non-human primates. OBJECTIVE Here we have investigated the relationship between plasma ceramides and metabolic syndrome in Rhesus macaques fed a high-fat and high-fructose (HFFD) 'western' diet. METHODS We investigated this relationship in cohorts of monkeys fed a HFFD for a period of 8 months to 5 years. Animals were classified as control, pre-diabetic or diabetic based on fasting plasma parameters and insulin sensitivity. RESULTS HFFD treatment produced significant increases in body weight and body fat and also resulted in a decline in insulin sensitivity. In parallel to the reduction in insulin sensitivity, significant increases in both plasma ceramide and dihydroceramide levels were observed, which further increased as animals progressed to the diabetic state. Plasma levels of the rare sphingolipid C18:0 deoxysphinganine, a marker of increased metabolic flux through serine palmitoyl transferase (SPT), were also elevated in both pre- and diabetic animals. Furthermore, plasma serine levels were significantly elevated in diabetic monkeys, which may indicate a shift in SPT substrate selectivity from serine to alanine or glycine. In contrast, branch chain amino acids were unchanged in pre-diabetic non-human primates, and only plasma valine levels were elevated in diabetic animals. CONCLUSION Together, these data indicate that HFFD induces de novo synthesis of ceramides in non-human primates, and that increased production of plasma ceramides is significantly correlated with the decline in insulin sensitivity.
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26
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Biological functions of sphingomyelins. Prog Lipid Res 2013; 52:424-37. [PMID: 23684760 DOI: 10.1016/j.plipres.2013.05.001] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 04/12/2013] [Accepted: 05/02/2013] [Indexed: 12/14/2022]
Abstract
Sphingomyelin (SM) is a dominant sphingolipid in membranes of mammalian cells and this lipid class is specifically enriched in the plasma membrane, the endocytic recycling compartment, and the trans Golgi network. The distribution of SM and cholesterol among cellular compartments correlate. Sphingolipids have extensive hydrogen-bonding capabilities which together with their saturated nature facilitate the formation of sphingolipid and SM-enriched lateral domains in membranes. Cholesterol prefers to interact with SMs and this interaction has many important functional consequences. In this review, the synthesis, regulation, and intracellular distribution of SMs are discussed. The many direct roles played by membrane SM in various cellular functions and processes will also be discussed. These include involvement in the regulation of endocytosis and receptor-mediated ligand uptake, in ion channel and G-protein coupled receptor function, in protein sorting, and functioning as receptor molecules for various bacterial toxins, and for non-bacterial pore-forming toxins. SM is also an important constituent of the eye lens membrane, and is believed to participate in the regulation of various nuclear functions. SM is an independent risk factor in the development of cardiovascular disease, and new studies have shed light on possible mechanism behind its role in atherogenesis.
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27
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Holland WL, Adams AC, Brozinick JT, Bui HH, Miyauchi Y, Kusminski CM, Bauer SM, Wade M, Singhal E, Cheng CC, Volk K, Kuo MS, Gordillo R, Kharitonenkov A, Scherer PE. An FGF21-adiponectin-ceramide axis controls energy expenditure and insulin action in mice. Cell Metab 2013; 17:790-7. [PMID: 23663742 PMCID: PMC3667496 DOI: 10.1016/j.cmet.2013.03.019] [Citation(s) in RCA: 413] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Revised: 01/22/2013] [Accepted: 03/29/2013] [Indexed: 11/18/2022]
Abstract
FGF21, a member of the fibroblast growth factor (FGF) superfamily, has recently emerged as a regulator of metabolism and energy utilization. However, the exact mechanism(s) whereby FGF21 mediates its actions have not been elucidated. There is considerable evidence that insulin resistance may arise from aberrant accumulation of intracellular lipids in insulin-responsive tissues due to lipotoxicity. In particular, the sphingolipid ceramide has been implicated in this process. Here, we show that FGF21 rapidly and robustly stimulates adiponectin secretion in rodents while diminishing accumulation of ceramides in obese animals. Importantly, adiponectin-knockout mice are refractory to changes in energy expenditure and ceramide-lowering effects evoked by FGF21 administration. Moreover, FGF21 lowers blood glucose levels and enhances insulin sensitivity in diabetic Lep(ob/ob) mice and diet-induced obese (DIO) mice only when adiponectin is functionally present. Collectively, these data suggest that FGF21 is a potent regulator of adiponectin secretion and that FGF21 critically depends on adiponectin to exert its glycemic and insulin sensitizing effects.
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Affiliation(s)
- William L. Holland
- Touchstone Diabetes Center, Department of Internal Medicine, Dallas, Texas 75390-8549
| | - Andrew C. Adams
- Lilly Research Laboratories, Division of Eli Lilly and Co., Indianapolis, Indiana
| | - Joseph T. Brozinick
- Lilly Research Laboratories, Division of Eli Lilly and Co., Indianapolis, Indiana
| | - Hai H. Bui
- Lilly Research Laboratories, Division of Eli Lilly and Co., Indianapolis, Indiana
| | - Yukiko Miyauchi
- Touchstone Diabetes Center, Department of Internal Medicine, Dallas, Texas 75390-8549
| | | | - Steven M. Bauer
- Lilly Research Laboratories, Division of Eli Lilly and Co., Indianapolis, Indiana
| | - Mark Wade
- Lilly Research Laboratories, Division of Eli Lilly and Co., Indianapolis, Indiana
| | - Esha Singhal
- Touchstone Diabetes Center, Department of Internal Medicine, Dallas, Texas 75390-8549
| | - Christine C. Cheng
- Lilly Research Laboratories, Division of Eli Lilly and Co., Indianapolis, Indiana
| | - Katherine Volk
- Lilly Research Laboratories, Division of Eli Lilly and Co., Indianapolis, Indiana
| | - Ming-Shang Kuo
- Lilly Research Laboratories, Division of Eli Lilly and Co., Indianapolis, Indiana
| | - Ruth Gordillo
- Touchstone Diabetes Center, Department of Internal Medicine, Dallas, Texas 75390-8549
| | - Alexei Kharitonenkov
- Lilly Research Laboratories, Division of Eli Lilly and Co., Indianapolis, Indiana
- Corresponding Authors: Alexei Kharitonenkov, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN, USA 46285, Telephone: (317) 276-0091, Fax: (317) 277-2934, . Philipp E. Scherer, Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX USA 75390-8549, Telephone: (214) 648-8715, Fax: (214) 648-8720,
| | - Philipp E. Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, Dallas, Texas 75390-8549
- Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-8549
- Corresponding Authors: Alexei Kharitonenkov, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN, USA 46285, Telephone: (317) 276-0091, Fax: (317) 277-2934, . Philipp E. Scherer, Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX USA 75390-8549, Telephone: (214) 648-8715, Fax: (214) 648-8720,
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28
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Martínez-Beamonte R, Lou-Bonafonte JM, Martínez-Gracia MV, Osada J. Sphingomyelin in high-density lipoproteins: structural role and biological function. Int J Mol Sci 2013; 14:7716-41. [PMID: 23571495 PMCID: PMC3645712 DOI: 10.3390/ijms14047716] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 03/20/2013] [Accepted: 03/29/2013] [Indexed: 11/16/2022] Open
Abstract
High-density lipoprotein (HDL) levels are an inverse risk factor for cardiovascular diseases, and sphingomyelin (SM) is the second most abundant phospholipid component and the major sphingolipid in HDL. Considering the marked presence of SM, the present review has focused on the current knowledge about this phospholipid by addressing its variable distribution among HDL lipoparticles, how they acquire this phospholipid, and the important role that SM plays in regulating their fluidity and cholesterol efflux from different cells. In addition, plasma enzymes involved in HDL metabolism such as lecithin-cholesterol acyltransferase or phospholipid transfer protein are inhibited by HDL SM content. Likewise, HDL SM levels are influenced by dietary maneuvers (source of protein or fat), drugs (statins or diuretics) and modified in diseases such as diabetes, renal failure or Niemann-Pick disease. Furthermore, increased levels of HDL SM have been shown to be an inverse risk factor for coronary heart disease. The complexity of SM species, described using new lipidomic methodologies, and their distribution in different HDL particles under many experimental conditions are promising avenues for further research in the future.
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Affiliation(s)
- Roberto Martínez-Beamonte
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Zaragoza E-50013, Spain; E-Mail:
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid E-28029, Spain; E-Mails: (J.M.L.-B.); (M.V.M.-G.)
| | - Jose M. Lou-Bonafonte
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid E-28029, Spain; E-Mails: (J.M.L.-B.); (M.V.M.-G.)
- Departamento de Farmacología y Fisiología, Facultad de Ciencias de la Salud y del Deporte, Universidad de Zaragoza, Huesca E-22002, Spain
| | - María V. Martínez-Gracia
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid E-28029, Spain; E-Mails: (J.M.L.-B.); (M.V.M.-G.)
| | - Jesús Osada
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Zaragoza E-50013, Spain; E-Mail:
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid E-28029, Spain; E-Mails: (J.M.L.-B.); (M.V.M.-G.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +34-976-761-644; Fax: +34-976-761-612
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Chakraborty M, Lou C, Huan C, Kuo MS, Park TS, Cao G, Jiang XC. Myeloid cell-specific serine palmitoyltransferase subunit 2 haploinsufficiency reduces murine atherosclerosis. J Clin Invest 2013; 123:1784-97. [PMID: 23549085 DOI: 10.1172/jci60415] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 01/24/2013] [Indexed: 12/15/2022] Open
Abstract
Serine palmitoyltransferase (SPT) is the first and rate-limiting enzyme of the de novo biosynthetic pathway of sphingomyelin (SM). Both SPT and SM have been implicated in the pathogenesis of atherosclerosis, the development of which is driven by macrophages; however, the role of SPT in macrophage-mediated atherogenesis is unknown. To address this issue, we have analyzed macrophage inflammatory responses and reverse cholesterol transport, 2 key mediators of atherogenesis, in SPT subunit 2-haploinsufficient (Sptlc2(+/-)) macrophages. We found that Sptlc2(+/-) macrophages have significantly lower SM levels in plasma membrane and lipid rafts. This reduction not only impaired inflammatory responses triggered by TLR4 and its downstream NF-κB and MAPK pathways, but also enhanced reverse cholesterol transport mediated by ABC transporters. LDL receptor-deficient (Ldlr(-/-)) mice transplanted with Sptlc2(+/-) bone marrow cells exhibited significantly fewer atherosclerotic lesions after high-fat and high-cholesterol diet feeding. Additionally, Ldlr(-/-) mice with myeloid cell-specific Sptlc2 haploinsufficiency exhibited significantly less atherosclerosis than controls. These findings suggest that SPT could be a novel therapeutic target in atherosclerosis.
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Affiliation(s)
- Mahua Chakraborty
- Department of Cell Biology, State University of New York Downstate Medical Center, New York, New York, USA
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Albinet V, Bats ML, Bedia C, Sabourdy F, Garcia V, Ségui B, Andrieu-Abadie N, Hornemann T, Levade T. Genetic disorders of simple sphingolipid metabolism. Handb Exp Pharmacol 2013:127-152. [PMID: 23579453 DOI: 10.1007/978-3-7091-1368-4_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A better understanding of the functions sphingolipids play in living organisms can be achieved by analyzing the biochemical and physiological changes that result from genetic alterations of sphingolipid metabolism. This review summarizes the current knowledge gained from studies both on human patients and mutant animals (mice, cats, dogs, and cattle) with genetic disorders of sphingolipid metabolism. Genetic alterations affecting the biosynthesis, transport, or degradation of simple sphingolipids are discussed.
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Affiliation(s)
- Virginie Albinet
- Institut National de la Santé et de la Recherche Médicale UMR1037, Centre de Recherches en Cancérologie de Toulouse, Team n°4, Université de Toulouse, CHU Rangueil, 84225, Toulouse Cedex 4, 31432, France
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31
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Impact of immune-metabolic interactions on age-related thymic demise and T cell senescence. Semin Immunol 2012; 24:321-30. [DOI: 10.1016/j.smim.2012.04.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 03/29/2012] [Accepted: 04/09/2012] [Indexed: 01/13/2023]
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Hornemann T, Worgall TS. Sphingolipids and atherosclerosis. Atherosclerosis 2012; 226:16-28. [PMID: 23075523 DOI: 10.1016/j.atherosclerosis.2012.08.041] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 08/06/2012] [Accepted: 08/22/2012] [Indexed: 11/19/2022]
Abstract
The atherosclerotic lesion contains a high amount of sphingolipids, a large group of structurally diverse lipids that regulate distinct biological functions beyond their role as structural membrane components. Assessment of their role in atherogenesis has been enabled after genes that regulate their metabolism had been identified and facilitated by the more wide availability of mass spectrometry. Here we discuss recent mechanistic insights obtained in animal and epidemiological studies that have greatly enhanced our understanding of mechanisms how sphingolipids affect the atherosclerotic process.
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Affiliation(s)
- Thorsten Hornemann
- Inst. for Clinical Chemistry, University Hospital Zuerich, Raemistrasse 100, 8091 Zuerich, Switzerland.
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Ruangsiriluk W, Grosskurth SE, Ziemek D, Kuhn M, des Etages SG, Francone OL. Silencing of enzymes involved in ceramide biosynthesis causes distinct global alterations of lipid homeostasis and gene expression. J Lipid Res 2012; 53:1459-71. [PMID: 22628619 PMCID: PMC3540863 DOI: 10.1194/jlr.m020941] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Dysregulation of ceramide synthesis has been associated with metabolic disorders such as atherosclerosis and diabetes. We examined the changes in lipid homeostasis and gene expression in Huh7 hepatocytes when the synthesis of ceramide is perturbed by knocking down serine pal mitoyltransferase subunits 1, 2, and 3 (SPTLC123) or dihydroceramide desaturase 1 (DEGS1). Although knocking down all SPTLC subunits is necessary to reduce total ceramides significantly, depleting DEGS1 is sufficient to produce a similar outcome. Lipidomic analysis of distribution and speciation of multiple lipid classes indicates an increase in phospholipids in SPTLC123-silenced cells, whereas DEGS1 depletion leads to the accumulation of sphingolipid intermediates, free fatty acids, and diacylglycerol. When cer amide synthesis is disrupted, the transcriptional profiles indicate inhibition in biosynthetic processes, downregulation of genes involved in general endomembrane trafficking, and upregulation of endocytosis and endosomal recycling. SPTLC123 silencing strongly affects the expression of genes involved with lipid metabolism. Changes in amino acid, sugar, and nucleotide metabolism, as well as vesicle trafficking between organelles, are more prominent in DEGS1-silenced cells. These studies are the first to provide a direct and comprehensive understanding at the lipidomic and transcriptomic levels of how Huh7 hepatocytes respond to changes in the inhibition of ceramide synthesis.
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Affiliation(s)
- Wanida Ruangsiriluk
- Department of Cardiovascular, Metabolic, and Endocrine Diseases, Pfizer Inc., Cambridge, MA, USA
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Lee SY, Kim JR, Hu Y, Khan R, Kim SJ, Bharadwaj KG, Davidson MM, Choi CS, Shin KO, Lee YM, Park WJ, Park IS, Jiang XC, Goldberg IJ, Park TS. Cardiomyocyte specific deficiency of serine palmitoyltransferase subunit 2 reduces ceramide but leads to cardiac dysfunction. J Biol Chem 2012; 287:18429-39. [PMID: 22493506 DOI: 10.1074/jbc.m111.296947] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The role of serine palmitoyltransferase (SPT) and de novo ceramide biosynthesis in cardiac ceramide and sphingomyelin metabolism is unclear. To determine whether the de novo synthetic pathways, rather than ceramide uptake from circulating lipoproteins, is important for heart ceramide levels, we created cardiomyocyte-specific deficiency of Sptlc2, a subunit of SPT. Heart-specific Sptlc2-deficient (hSptlc2 KO) mice had a >35% reduction in ceramide, which was limited to C18:0 and very long chain ceramides. Sphingomyelinase expression, and levels of sphingomyelin and diacylglycerol were unchanged. But surprisingly phospholipids and acyl CoAs contained increased saturated long chain fatty acids. hSptlc2 KO mice had decreased fractional shortening and thinning of the cardiac wall. While the genes regulating glucose and fatty acid metabolism were not changed, expression of cardiac failure markers and the genes involved in the formation of extracellular matrices were up-regulated in hSptlc2 KO hearts. In addition, ER-stress markers were up-regulated leading to increased apoptosis. These results suggest that Sptlc2-mediated de novo ceramide synthesis is an essential source of C18:0 and very long chain, but not of shorter chain, ceramides in the heart. Changes in heart lipids other than ceramide levels lead to cardiac toxicity.
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Affiliation(s)
- Su-Yeon Lee
- Department of Life Science, Gachon University, Seongnam-Si, Gyeonggi-Do, Republic of Korea
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Receptor-mediated activation of ceramidase activity initiates the pleiotropic actions of adiponectin. Nat Med 2010; 17:55-63. [PMID: 21186369 PMCID: PMC3134999 DOI: 10.1038/nm.2277] [Citation(s) in RCA: 672] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 10/20/2010] [Indexed: 12/12/2022]
Abstract
The adipocyte-derived secretory factor adiponectin promotes insulin sensitivity,
decreases inflammation and promotes cell survival. To date, no unifying mechanism explains how
adiponectin can exert such a variety of beneficial systemic effects. Here, we show that
adiponectin potently stimulates a ceramidase activity associated with its two receptors,
adipoR1 and adipoR2, and enhances ceramide catabolism and formation of its anti-apoptotic
metabolite – sphingosine-1-phosphate (S1P), independently of AMPK. Using models of
inducible apoptosis in pancreatic β-cells and cardiomyocytes, we show that transgenic
overproduction of adiponectin decreases caspase-8 mediated death, while genetic adiponectin
ablation enhances apoptosis in vivo through a sphingolipid-mediated pathway.
Ceramidase activity is impaired in cells lacking both adiponectin receptor isoforms, leading to
elevated ceramide levels and enhanced susceptibility to palmitate-induced cell death. Combined,
our observations suggest a novel unifying mechanism of action for the beneficial systemic
effects exerted by adiponectin, with sphingolipid metabolism as its core upstream
component.
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Fan Y, Shi F, Liu J, Dong J, Bui HH, Peake DA, Kuo MS, Cao G, Jiang XC. Selective reduction in the sphingomyelin content of atherogenic lipoproteins inhibits their retention in murine aortas and the subsequent development of atherosclerosis. Arterioscler Thromb Vasc Biol 2010; 30:2114-20. [PMID: 20814016 DOI: 10.1161/atvbaha.110.213363] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVE We used the sphingomyelin (SM) synthase 2 (Sms2) gene knockout (KO) approach to test our hypothesis that selectively decreasing plasma lipoprotein SM can play an important role in preventing atherosclerosis. METHODS AND RESULTS The sphingolipid de novo synthesis pathway is considered a promising target for pharmacological intervention in atherosclerosis. However, its potential is hampered because the substance's atherogenic mechanism is not completely understood. We prepared Sms2 and apolipoprotein E (Apoe) double-KO mice. They showed a significant decrease in plasma lipoprotein SM levels (35%, P<0.01) and a significant increase in ceramide and dihydroceramide levels (87.5% and 27%, respectively; P<0.01) but no significant changes in other tested sphingolipids, cholesterol, and triglyceride. Non-high-density lipoproteins from the double-KO mice showed a reduction of SM, but not cholesterol, and displayed less tendency toward aortic sphingomyelinase-mediated lipoprotein aggregation in vitro and retention in aortas in vivo when compared with controls. More important, at the age of 19 weeks, Sms2 KO/Apoe KO mice showed a significant reduction in atherosclerotic lesions of the aortic arch and root (52%, P<0.01) compared with controls. The Sms2 KO/Apoe KO brachiocephalic artery contained significantly less SM, ceramide, free cholesterol, and cholesteryl ester (35%, 32%, 58%, and 60%, respectively; P<0.01) than that of the Apoe KO brachiocephalic artery. CONCLUSIONS Decreasing plasma SM levels through decreasing SMS2 activity could become a promising treatment for atherosclerosis.
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Affiliation(s)
- Yifan Fan
- Department of Cardiology, Renmin Hospotal, Wuhan University, Wuhan, China
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