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Chen J, Lewis MA, Wai A, Yin L, Dawson SJ, Ingham NJ, Steel KP. A new mutation of Sgms1 causes gradual hearing loss associated with a reduced endocochlear potential. Hear Res 2024; 451:109091. [PMID: 39067415 DOI: 10.1016/j.heares.2024.109091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 07/04/2024] [Accepted: 07/22/2024] [Indexed: 07/30/2024]
Abstract
Sgms1 encodes sphingomyelin synthase 1, an enzyme in the sphingosine-1-phosphate signalling pathway, and was previously reported to underlie hearing impairment in the mouse. A new mouse allele, Sgms1tm1a, unexpectedly showed normal Auditory Brainstem Response thresholds. We found that the Sgms1tm1a mutation led to incomplete knockdown of transcript to 20 % of normal values, which was enough to support normal hearing. The Sgms1tm1b allele was generated by knocking out exon 7, leading to a complete lack of detectable transcript in the inner ear. Sgms1tm1b homozygotes showed largely normal auditory brainstem response thresholds at first, followed by progressive loss of sensitivity until they showed severe impairment at 6 months old. The endocochlear potential was consistently reduced in Sgms1tm1b mutants at 3, 4 and 8 weeks old, to around 80 mV compared with around 120 mV in control littermates. The stria vascularis showed a characteristic irregularity of marginal cell surfaces and patchy loss of Kcnq1 expression at their apical membrane, and expression analysis of the lateral wall suggested that marginal cells were the most likely initial site of dysfunction in the mutants. Finally, significant association of auditory thresholds with DNA markers within and close to the human SGMS1 gene were found in the 1958 Birth Cohort, suggesting that SGMS1 variants may play a role in the range of hearing abilities in the human population.
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Affiliation(s)
- Jing Chen
- Wolfson Sensory, Pain and Regeneration Centre, King's College London, London SE1 1UL, United Kingdom
| | - Morag A Lewis
- Wolfson Sensory, Pain and Regeneration Centre, King's College London, London SE1 1UL, United Kingdom
| | - Alisa Wai
- Wolfson Sensory, Pain and Regeneration Centre, King's College London, London SE1 1UL, United Kingdom
| | - Lucia Yin
- Wolfson Sensory, Pain and Regeneration Centre, King's College London, London SE1 1UL, United Kingdom
| | - Sally J Dawson
- UCL Ear Institute, University College London, London WC1X 8EE, United Kingdom
| | - Neil J Ingham
- Wolfson Sensory, Pain and Regeneration Centre, King's College London, London SE1 1UL, United Kingdom
| | - Karen P Steel
- Wolfson Sensory, Pain and Regeneration Centre, King's College London, London SE1 1UL, United Kingdom.
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Wilkerson JL, Tatum SM, Holland WL, Summers SA. Ceramides are fuel gauges on the drive to cardiometabolic disease. Physiol Rev 2024; 104:1061-1119. [PMID: 38300524 PMCID: PMC11381030 DOI: 10.1152/physrev.00008.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/02/2024] Open
Abstract
Ceramides are signals of fatty acid excess that accumulate when a cell's energetic needs have been met and its nutrient storage has reached capacity. As these sphingolipids accrue, they alter the metabolism and survival of cells throughout the body including in the heart, liver, blood vessels, skeletal muscle, brain, and kidney. These ceramide actions elicit the tissue dysfunction that underlies cardiometabolic diseases such as diabetes, coronary artery disease, metabolic-associated steatohepatitis, and heart failure. Here, we review the biosynthesis and degradation pathways that maintain ceramide levels in normal physiology and discuss how the loss of ceramide homeostasis drives cardiometabolic pathologies. We highlight signaling nodes that sense small changes in ceramides and in turn reprogram cellular metabolism and stimulate apoptosis. Finally, we evaluate the emerging therapeutic utility of these unique lipids as biomarkers that forecast disease risk and as targets of ceramide-lowering interventions that ameliorate disease.
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Affiliation(s)
- Joseph L Wilkerson
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, United States
| | - Sean M Tatum
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, United States
| | - William L Holland
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, United States
| | - Scott A Summers
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, United States
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3
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Hu K, Zhang Q, Chen Y, Yang J, Xia Y, Rao B, Li S, Shen Y, Cao M, Lu H, Qin A, Jiang XC, Yao D, Zhao J, Zhou L, Cao Y. Cryo-EM structure of human sphingomyelin synthase and its mechanistic implications for sphingomyelin synthesis. Nat Struct Mol Biol 2024; 31:884-895. [PMID: 38388831 DOI: 10.1038/s41594-024-01237-2] [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: 04/12/2023] [Accepted: 01/31/2024] [Indexed: 02/24/2024]
Abstract
Sphingomyelin (SM) has key roles in modulating mammalian membrane properties and serves as an important pool for bioactive molecules. SM biosynthesis is mediated by the sphingomyelin synthase (SMS) family, comprising SMS1, SMS2 and SMS-related (SMSr) members. Although SMS1 and SMS2 exhibit SMS activity, SMSr possesses ceramide phosphoethanolamine synthase activity. Here we determined the cryo-electron microscopic structures of human SMSr in complexes with ceramide, diacylglycerol/phosphoethanolamine and ceramide/phosphoethanolamine (CPE). The structures revealed a hexameric arrangement with a reaction chamber located between the transmembrane helices. Within this structure, a catalytic pentad E-H/D-H-D was identified, situated at the interface between the lipophilic and hydrophilic segments of the reaction chamber. Additionally, the study unveiled the two-step synthesis process catalyzed by SMSr, involving PE-PLC (phosphatidylethanolamine-phospholipase C) hydrolysis and the subsequent transfer of the phosphoethanolamine moiety to ceramide. This research provides insights into the catalytic mechanism of SMSr and expands our understanding of sphingolipid metabolism.
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Affiliation(s)
- Kexin Hu
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qing Zhang
- Department of Orthopaedics, Shanghai Key Laboratory of Orthopaedic Implant, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Frontiers Science Center of Degeneration and Regeneration in Skeletal System, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Yang Chen
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jintong Yang
- Department of Medicinal Chemistry, School of Pharmacy, Fudan University, Shanghai, China
| | - Ying Xia
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bing Rao
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Orthopaedics, Shanghai Key Laboratory of Orthopaedic Implant, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shaobai Li
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yafeng Shen
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mi Cao
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hongliang Lu
- College of Basic Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - An Qin
- Department of Orthopaedics, Shanghai Key Laboratory of Orthopaedic Implant, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Frontiers Science Center of Degeneration and Regeneration in Skeletal System, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xian-Cheng Jiang
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, NY, USA
| | - Deqiang Yao
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- Institute of Aging & Tissue Regeneration, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Jie Zhao
- Department of Orthopaedics, Shanghai Key Laboratory of Orthopaedic Implant, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- Shanghai Frontiers Science Center of Degeneration and Regeneration in Skeletal System, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Lu Zhou
- Department of Medicinal Chemistry, School of Pharmacy, Fudan University, Shanghai, China.
| | - Yu Cao
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- Department of Orthopaedics, Shanghai Key Laboratory of Orthopaedic Implant, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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Hu D, Zhang H, Liu Z, Ibáñez CF, Tie C, Xie M. Sphingomyelin is involved in regulating UCP1-mediated nonshivering thermogenesis. J Lipid Res 2024; 65:100559. [PMID: 38729351 PMCID: PMC11166878 DOI: 10.1016/j.jlr.2024.100559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 04/29/2024] [Accepted: 05/02/2024] [Indexed: 05/12/2024] Open
Abstract
Adipogenesis is one of the major mechanisms for adipose tissue expansion, during which spindle-shaped mesenchymal stem cells commit to the fate of adipocyte precursors and differentiate into round-shaped fat-laden adipocytes. Here, we investigated the lipidomic profile dynamics of ex vivo-differentiated brown and white adipocytes derived from the stromal vascular fractions of interscapular brown (iBAT) and inguinal white adipose tissues. We showed that sphingomyelin was specifically enriched in terminally differentiated brown adipocytes, but not white adipocytes. In line with this, freshly isolated adipocytes of iBAT showed higher sphingomyelin content than those of inguinal white adipose tissue. Upon cold exposure, sphingomyelin abundance in iBAT gradually decreased in parallel with reduced sphingomyelin synthase 1 protein levels. Cold-exposed animals treated with an inhibitor of sphingomyelin hydrolases failed to maintain core body temperature and showed reduced oxygen consumption and iBAT UCP1 levels. Conversely, blockade of sphingomyelin synthetic enzymes resulted in enhanced nonshivering thermogenesis, reflected by elevated body temperature and UCP1 levels. Taken together, our results uncovered a relation between sphingomyelin abundance and fine-tuning of UCP1-mediated nonshivering thermogenesis.
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Affiliation(s)
- Detian Hu
- Chinese Institute for Brain Research, Zhongguancun Life Science Park, Beijing, China; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Houyu Zhang
- Chinese Institute for Brain Research, Zhongguancun Life Science Park, Beijing, China; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Zhen Liu
- Yuanpei College, Peking University, Beijing, China
| | - Carlos F Ibáñez
- Chinese Institute for Brain Research, Zhongguancun Life Science Park, Beijing, China; School of Life Sciences, Peking University, Beijing, China; Peking-Tsinghua Center for Life Sciences, Beijing, China; PKU-IDG/McGovern Institute for Brain Research, Beijing, China; Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Cai Tie
- State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources, China University of Mining and Technology-Beijing, Beijing, China; School of Chemical and Environmental Engineering, China University of Mining and Technology-Beijing, Beijing, China
| | - Meng Xie
- PKU-IDG/McGovern Institute for Brain Research, Beijing, China; School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China; Department of Biosciences and Nutrition, Karolinska Institute, Flemingsberg, Sweden.
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Yu H, Niu Y, Lei X, Xie C, Yan X. Multi-Omics Analysis Reveals Sphingomyelin Accumulation, Glycerolipids Loss, and Disorders of Lipid Metabolism Regulated by Leucine Deprivation in the Liver of Mice. Mol Nutr Food Res 2024; 68:e2300567. [PMID: 38059795 DOI: 10.1002/mnfr.202300567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/27/2023] [Indexed: 12/08/2023]
Abstract
SCOPE Branched-chain amino acids, especially leucine, have been reported to play a role in regulating lipid metabolism. This study aims to examine the effects of leucine deprivation on hepatic lipid metabolism. METHODS AND RESULTS C57BL/6 mice are fed with a chow diet (control group, n = 8) or a leucine-free diet (-Leu group, n = 8) for 7 days. Histology, lipidomics, targeted metabolomics, and transcriptomics are performed to analyze the liver tissue. Compared to control group, -Leu group exhibits a notably reduced liver weight, accompanied by hepatic injury, and disorders of lipid metabolism. The level of sphingomyelin (SM) is significantly increased in the liver of -Leu group, while the glycerolipids (GL) level is significantly decreased. The expression of sphingomyelin synthase 1 (SGMS1) is upregulated by leucine deprivation in a time-dependent manner, leading to hepatic SM accumulation. Moreover, leucine deprivation results in hepatic GL loss via suppressing fatty acid synthase (FASN) and acetyl-CoA carboxylase 1 (ACC1) expression. CONCLUSION The findings demonstrate that leucine deprivation results in abnormal lipid metabolism in the liver, mainly manifested as SM accumulation and GL loss. These results provide insights into the role of leucine in regulating lipid metabolism.
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Affiliation(s)
- Haonan Yu
- National Key Laboratory of Agricultural Microbiology, Frontiers Science Center for Animal Breeding and Sustainable Production, Hubei Hongshan Laboratory, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, 430070, China
- Hubei Provincial Engineering Laboratory for Pig Precision Feeding and Feed Safety Technology, Wuhan, Hubei, 430070, China
| | - Yaorong Niu
- National Key Laboratory of Agricultural Microbiology, Frontiers Science Center for Animal Breeding and Sustainable Production, Hubei Hongshan Laboratory, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, 430070, China
- Hubei Provincial Engineering Laboratory for Pig Precision Feeding and Feed Safety Technology, Wuhan, Hubei, 430070, China
| | - Xinyu Lei
- National Key Laboratory of Agricultural Microbiology, Frontiers Science Center for Animal Breeding and Sustainable Production, Hubei Hongshan Laboratory, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, 430070, China
- Hubei Provincial Engineering Laboratory for Pig Precision Feeding and Feed Safety Technology, Wuhan, Hubei, 430070, China
| | - Chunlin Xie
- National Key Laboratory of Livestock and Poultry Breeding, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangzhou, Guangdong, 510640, China
| | - Xianghua Yan
- National Key Laboratory of Agricultural Microbiology, Frontiers Science Center for Animal Breeding and Sustainable Production, Hubei Hongshan Laboratory, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, 430070, China
- Hubei Provincial Engineering Laboratory for Pig Precision Feeding and Feed Safety Technology, Wuhan, Hubei, 430070, China
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Suzuki R, Murakami C, Dilimulati K, Atsuta-Tsunoda K, Kawai T, Sakane F. Human sphingomyelin synthase 1 generates diacylglycerol in the presence and absence of ceramide via multiple enzymatic activities. FEBS Lett 2023; 597:2672-2686. [PMID: 37715942 DOI: 10.1002/1873-3468.14735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/24/2023] [Accepted: 09/01/2023] [Indexed: 09/18/2023]
Abstract
Sphingomyelin (SM) synthase 1 (SMS1), which is involved in lipodystrophy, deafness, and thrombasthenia, generates diacylglycerol (DG) and SM using phosphatidylcholine (PC) and ceramide as substrates. Here, we found that SMS1 possesses DG-generating activities via hydrolysis of PC and phosphatidylethanolamine (PE) in the absence of ceramide and ceramide phosphoethanolamine synthase (CPES) activity. In the presence of the same concentration (4.7 mol%) of PC and ceramide, the amounts of DG produced by SMS and PC-phospholipase C (PLC) activities of SMS1 were approximately 65% and 35% of total DG production, respectively. PC-PLC activity showed substrate selectivity for saturated and/or monounsaturated fatty acid-containing PC species. A PC-PLC/SMS inhibitor, D609, inhibited only SMS activity. Mn2+ inhibited only PC-PLC activity. Intriguingly, DG attenuated SMS/CPES activities. Our study indicates that SMS1 is a unique enzyme with PC-PLC/PE-PLC/SMS/CPES activities.
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Affiliation(s)
- Rika Suzuki
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
| | - Chiaki Murakami
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
- Institute for Advanced Academic Research, Chiba University, Japan
| | - Kamila Dilimulati
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
| | | | - Takuma Kawai
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
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Savikj M, Stocks B, Sato S, Caidahl K, Krook A, Deshmukh AS, Zierath JR, Wallberg-Henriksson H. Exercise timing influences multi-tissue metabolome and skeletal muscle proteome profiles in type 2 diabetic patients - A randomized crossover trial. Metabolism 2022; 135:155268. [PMID: 35908579 DOI: 10.1016/j.metabol.2022.155268] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/10/2022] [Accepted: 07/22/2022] [Indexed: 01/06/2023]
Abstract
AIMS/HYPOTHESIS Metabolic effects of exercise may partly depend on the time-of-day when exercise is performed. We tested the hypothesis that exercise timing affects the adaptations in multi-tissue metabolome and skeletal muscle proteome profiles in men with type 2 diabetes. METHODS Men fitting the inclusion (type 2 diabetes, age 45-68 years and body mass index 23-33 kg/m2) and exclusion criteria (insulin treatment, smoking, concurrent systemic disease, and regular exercise training) were included in a randomized crossover trial (n = 15). Participants included in this metabolomics and proteomics analysis fully completed all exercise sessions (n = 8). The trial consisted of two weeks of high-intensity interval training (HIT) (three sessions/week) either in the morning (08:00, n = 5) or afternoon (16:45, n = 3), a two-week wash-out period, and an additional two weeks of HIT at the opposing time. Participants and researchers were not blinded to group allocation. Blood, skeletal muscle and subcutaneous adipose tissue were obtained before the first, and after each training period. Broad-spectrum, untargeted proteomic analysis was performed on skeletal muscle, and metabolomic analysis was performed on all biosamples. Differential content was assessed by linear regression and pathway set enrichment analyses were performed. Coordinated metabolic changes across tissues were identified by Spearman correlation analysis. RESULTS Metabolic and proteomic profiles remained stable after two weeks of HIT, and individual metabolites and proteins were not altered, irrespective of the time of day at which the training was performed. However, coordinated changes in relevant metabolic pathways and protein categories were identified. Morning and afternoon HIT similarly increased plasma diacylglycerols, skeletal muscle acyl-carnitines, and subcutaneous adipose tissue sphingomyelins and lysophospholipids. Acyl-carnitines were central to training-induced metabolic cross-talk across tissues. Plasma carbohydrates, via the penthose phosphate pathway, were increased and skeletal muscle lipids were decreased after morning compared to afternoon HIT. Skeletal muscle lipoproteins were higher, and mitochondrial complex III abundance was lower after morning compared to afternoon HIT. CONCLUSIONS/INTERPRETATION We provide a comprehensive analysis of a multi-tissue metabolomic and skeletal muscle proteomic responses to training at different times of the day in men with type 2 diabetes. Increased circulating lipids and changes in adipose tissue lipid composition were common between morning and afternoon HIT. However, afternoon HIT increased skeletal muscle lipids and mitochondrial content to a greater degree than morning training. Thus, there is a diurnal component in the metabolomic and proteomic response to exercise in men with type 2 diabetes. The clinical relevance of this response warrants further investigation.
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Affiliation(s)
- Mladen Savikj
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Ben Stocks
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Shogo Sato
- Center for Epigenetics and Metabolism, INSERM U1233, Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Kenneth Caidahl
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Krook
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Atul S Deshmukh
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Juleen R Zierath
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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8
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Sphingomyelin Synthase Family and Phospholipase Cs. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1372:77-86. [DOI: 10.1007/978-981-19-0394-6_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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9
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Li Z, Chiang YP, He M, Worgall TS, Zhou H, Jiang XC. Liver sphingomyelin synthase 1 deficiency causes steatosis, steatohepatitis, fibrosis, and tumorigenesis: An effect of glucosylceramide accumulation. iScience 2021; 24:103449. [PMID: 34927020 PMCID: PMC8649732 DOI: 10.1016/j.isci.2021.103449] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 10/21/2021] [Accepted: 11/11/2021] [Indexed: 11/30/2022] Open
Abstract
Glucosylceramide (GluCer) was accumulated in sphingomyelin synthase 1 (SMS1) but not SMS2 deficient mouse tissues. In current study, we studied GluCer accumulation-mediated metabolic consequences. Livers from liver-specific Sms1/global Sms2 double-knockout (dKO) exhibited severe steatosis under a high-fat diet. Moreover, chow diet-fed ≥6-month-old dKO mice had liver impairment, inflammation, and fibrosis, compared with wild type and Sms2 KO mice. RNA sequencing showed 3- to 12-fold increases in various genes which are involved in lipogenesis, inflammation, and fibrosis. Further, we found that direct GluCer treatment (in vitro and in vivo) promoted hepatocyte to secrete more activated TGFβ1, which stimulated more collagen 1α1 production in hepatic stellate cells. Additionally, GluCer promoted more β-catenin translocation into the nucleus, thus promoting tumorigenesis. Importantly, human NASH patients had higher liver GluCer synthase and higher plasma GluCer. These findings implicated that GluCer accumulation is one of triggers promoting the development of NAFLD into NASH, then, fibrosis, and tumorigenesis.
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Affiliation(s)
- Zhiqiang Li
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Yeun-po Chiang
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Mulin He
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | | | | | - Xian-Cheng Jiang
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
- Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York, USA
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Choi RH, Tatum SM, Symons JD, Summers SA, Holland WL. Ceramides and other sphingolipids as drivers of cardiovascular disease. Nat Rev Cardiol 2021; 18:701-711. [PMID: 33772258 PMCID: PMC8978615 DOI: 10.1038/s41569-021-00536-1] [Citation(s) in RCA: 154] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/22/2021] [Indexed: 02/03/2023]
Abstract
Increases in calorie consumption and sedentary lifestyles are fuelling a global pandemic of cardiometabolic diseases, including coronary artery disease, diabetes mellitus, cardiomyopathy and heart failure. These lifestyle factors, when combined with genetic predispositions, increase the levels of circulating lipids, which can accumulate in non-adipose tissues, including blood vessel walls and the heart. The metabolism of these lipids produces bioactive intermediates that disrupt cellular function and survival. A compelling body of evidence suggests that sphingolipids, such as ceramides, account for much of the tissue damage in these cardiometabolic diseases. In humans, serum ceramide levels are proving to be accurate biomarkers of adverse cardiovascular disease outcomes. In mice and rats, pharmacological inhibition or depletion of enzymes driving de novo ceramide synthesis prevents the development of diabetes, atherosclerosis, hypertension and heart failure. In cultured cells and isolated tissues, ceramides perturb mitochondrial function, block fuel usage, disrupt vasodilatation and promote apoptosis. In this Review, we discuss the body of literature suggesting that ceramides are drivers - and not merely passengers - on the road to cardiovascular disease. Moreover, we explore the feasibility of therapeutic strategies to lower ceramide levels to improve cardiovascular health.
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Affiliation(s)
- Ran Hee Choi
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
| | - Sean M Tatum
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
| | - J David Symons
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
| | - Scott A Summers
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA.
| | - William L Holland
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
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Taniguchi M, Okazaki T. Role of ceramide/sphingomyelin (SM) balance regulated through "SM cycle" in cancer. Cell Signal 2021; 87:110119. [PMID: 34418535 DOI: 10.1016/j.cellsig.2021.110119] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 08/16/2021] [Accepted: 08/16/2021] [Indexed: 12/15/2022]
Abstract
Sphingomyelin synthase (SMS), which comprises of two isozymes, SMS1 and SMS2, is the only enzyme that generates sphingomyelin (SM) by transferring phosphocholine of phosphatidylcholine to ceramide in mammals. Conversely, ceramide is generated from SM hydrolysis via sphingomyelinases (SMases), ceramide de novo synthesis, and the salvage pathway. The biosynthetic pathway for SM and ceramide content by SMS and SMase, respectively, is called "SM cycle." SM forms a SM-rich microdomain on the cell membrane to regulate signal transduction, such as proliferation/survival, migration, and inflammation. On the other hand, ceramide acts as a lipid mediator by forming a ceramide-rich platform on the membrane, and ceramide exhibits physiological actions such as cell death, cell cycle arrest, and autophagy induction. Therefore, the regulation of ceramide/SM balance by SMS and SMase is responsible for diverse cell functions not only in physiological cells but also in cancer cells. This review outlines the implications of ceramide/SM balance through "SM cycle" in cancer progression and prevention. In addition, the possible involvement of "SM cycle" is introduced in anti-cancer tumor immunity, which has become a hot topic to innovate a more effective and safer way to conquer cancer in recent years.
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Affiliation(s)
- Makoto Taniguchi
- Department of Life Science, Medical Research Institute, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Kahoku 920-0293, Japan
| | - Toshiro Okazaki
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi-shi, Ishikawa 921-8836, Japan; Faculty of Advanced Life Science, Graduate School of Life Science, Hokkaido University, Kita 10, Nishi 8, Kita-ku, Sapporo 060-0810, Japan.
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12
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Quinville BM, Deschenes NM, Ryckman AE, Walia JS. A Comprehensive Review: Sphingolipid Metabolism and Implications of Disruption in Sphingolipid Homeostasis. Int J Mol Sci 2021; 22:ijms22115793. [PMID: 34071409 PMCID: PMC8198874 DOI: 10.3390/ijms22115793] [Citation(s) in RCA: 104] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/23/2021] [Accepted: 05/24/2021] [Indexed: 12/16/2022] Open
Abstract
Sphingolipids are a specialized group of lipids essential to the composition of the plasma membrane of many cell types; however, they are primarily localized within the nervous system. The amphipathic properties of sphingolipids enable their participation in a variety of intricate metabolic pathways. Sphingoid bases are the building blocks for all sphingolipid derivatives, comprising a complex class of lipids. The biosynthesis and catabolism of these lipids play an integral role in small- and large-scale body functions, including participation in membrane domains and signalling; cell proliferation, death, migration, and invasiveness; inflammation; and central nervous system development. Recently, sphingolipids have become the focus of several fields of research in the medical and biological sciences, as these bioactive lipids have been identified as potent signalling and messenger molecules. Sphingolipids are now being exploited as therapeutic targets for several pathologies. Here we present a comprehensive review of the structure and metabolism of sphingolipids and their many functional roles within the cell. In addition, we highlight the role of sphingolipids in several pathologies, including inflammatory disease, cystic fibrosis, cancer, Alzheimer’s and Parkinson’s disease, and lysosomal storage disorders.
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13
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Daian F, Esper BS, Ashrafi N, Yu GQ, Luciano G, Moorthi S, Luberto C. Regulation of human sphingomyelin synthase 1 translation through its 5'-untranslated region. FEBS Lett 2020; 594:3751-3764. [PMID: 33037626 PMCID: PMC7756225 DOI: 10.1002/1873-3468.13952] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 09/04/2020] [Indexed: 11/11/2022]
Abstract
Bcr‐abl1 oncogene causes a shift in the transcription start site of the SMS1 gene (SGMS1) encoding the sphingomyelin (SM) synthesizing enzyme, sphingomyelin synthase 1 (SMS1). This results in an mRNA with a significantly shorter 5′‐UTR, called 7‐SGMS1, which is translated more efficiently than another transcript (IIb‐SGMS1) with a longer 5′UTR in Bcr‐abl1‐positive cells. Here, we determine the effects of these alternative 5′UTRs on SMS1 translation and investigate the key features underlying such regulation. First, the presence of the longer IIb 5′UTR is sufficient to greatly impair translation of a reporter gene. Deletion of the upstream open reading frame (−164 nt) or of the predicted stem‐loops in the 5′UTR of IIb‐SGMS1 has minimal effects on SGMS1 translation. Conversely, deletion of nucleotides −310 to −132 enhanced transcription of IIb‐SGMS1 to reach that of 7‐SGMS1. We thus suggest that regulatory features within nucleotides −310 and −132 modulate IIb‐SGMS1 translation efficiency.
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Affiliation(s)
- Foysal Daian
- Renaissance School of Medicine, Stony Brook University, NY, USA
| | | | - Navid Ashrafi
- Department of Physiology and Biophysics, Stony Brook University, NY, USA
| | - Gui-Qin Yu
- Department of Physiology and Biophysics, Stony Brook University, NY, USA
| | - Gabriella Luciano
- Department of Physiology and Biophysics, Stony Brook University, NY, USA
| | - Sitapriya Moorthi
- Department of Physiology and Biophysics, Stony Brook University, NY, USA
| | - Chiara Luberto
- Department of Physiology and Biophysics, Stony Brook University, NY, USA
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14
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De Miguel C, Hamrick WC, Sedaka R, Jagarlamudi S, Asico LD, Jose PA, Cuevas S. Uncoupling Protein 2 Increases Blood Pressure in DJ -1 Knockout Mice. J Am Heart Assoc 2020; 8:e011856. [PMID: 30995881 PMCID: PMC6512091 DOI: 10.1161/jaha.118.011856] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background The redox-sensitive chaperone DJ -1 and uncoupling protein 2 are protective against mitochondrial oxidative stress. We previously reported that renal-selective depletion and germline deletion of DJ -1 increases blood pressure in mice. This study aimed to determine the mechanisms involved in the oxidative stress-mediated hypertension in DJ -1 -/- mice. Methods and Results There were no differences in sodium excretion, renal renin expression, renal NADPH oxidase activity, and serum creatinine levels between DJ -1 -/- and wild-type mice. Renal expression of nitro-tyrosine, malondialdehyde, and urinary kidney injury marker-1 were increased in DJ -1 -/- mice relative to wild-type littermates. mRNA expression of mitochondrial heat shock protein 60 was also elevated in kidneys from DJ -1 -/- mice, indicating the presence of oxidative stress. Tempol-treated DJ -1 -/- mice presented higher serum nitrite/nitrate levels than vehicle-treated DJ -1 -/- mice, suggesting a role of the NO system in the high blood pressure of this model. Tempol treatment normalized renal kidney injury marker-1 and malondialdehyde expression as well as blood pressure in DJ -1 -/- mice, but had no effect in wild-type mice. The renal Ucp2 mRNA expression was increased in DJ -1 -/- mice versus wild-type and was also normalized by tempol. The renal-selective silencing of Ucp2 led to normalization of blood pressure and serum nitrite/nitrate ratio in DJ -1 -/- mice. Conclusions The deletion of DJ -1 leads to oxidative stress-induced hypertension associated with downregulation of NO function, and overexpression of Ucp2 in the kidney increases blood pressure in DJ -1 -/- mice. To our knowledge, this is the first report providing evidence of the role of uncoupling protein 2 in blood pressure regulation.
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Affiliation(s)
- Carmen De Miguel
- 1 Section of Cardio-Renal Physiology and Medicine Division of Nephrology Department of Medicine University of Alabama at Birmingham AL
| | - William C Hamrick
- 1 Section of Cardio-Renal Physiology and Medicine Division of Nephrology Department of Medicine University of Alabama at Birmingham AL
| | - Randee Sedaka
- 1 Section of Cardio-Renal Physiology and Medicine Division of Nephrology Department of Medicine University of Alabama at Birmingham AL
| | - Sudha Jagarlamudi
- 2 Division of Renal Diseases & Hypertension Department of Medicine The George Washington University School of Medicine and Health Sciences Washington DC
| | - Laureano D Asico
- 2 Division of Renal Diseases & Hypertension Department of Medicine The George Washington University School of Medicine and Health Sciences Washington DC
| | - Pedro A Jose
- 2 Division of Renal Diseases & Hypertension Department of Medicine The George Washington University School of Medicine and Health Sciences Washington DC
| | - Santiago Cuevas
- 3 Research Center for Genetic Medicine Children's National Health System Washington DC
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15
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Taniguchi M, Okazaki T. Ceramide/Sphingomyelin Rheostat Regulated by Sphingomyelin Synthases and Chronic Diseases in Murine Models. J Lipid Atheroscler 2020; 9:380-405. [PMID: 33024732 PMCID: PMC7521967 DOI: 10.12997/jla.2020.9.3.380] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/16/2020] [Accepted: 07/19/2020] [Indexed: 12/16/2022] Open
Abstract
Ceramide and sphingomyelin (SM) are major components of the double membrane-bound sphingolipids. Ceramide is an essential bioactive lipid involved in numerous cell processes including apoptosis, necrosis, and autophagy-dependent cell death. Inversely, SM regulates opposite cellular processes such as proliferation and migration by changing receptor-mediated signal transduction in the lipid microdomain. SM is generated through a transfer of phosphocholine from phosphatidylcholine to ceramide by SM synthases (SMSs). Research during the past several decades has revealed that the ceramide/SM balance in cellular membranes regulated by SMSs is important to decide the cell fate, survival, and proliferation. In addition, recent experimental studies utilizing SMS knockout mice and murine disease models provide evidence that SMS-regulated ceramide/SM balance is involved in human diseases. Here, we review the basic structural and functional characteristics of SMSs and focus on their cellular functions through the regulation of ceramide/SM balance in membrane microdomains. In addition, we present the pathological or physiological implications of SMSs by analyzing their role in SMS-knockout mice and human disease models. This review finally presents evidence indicating that the regulation of ceramide/SM balance through SMS could be a therapeutic target for human disorders.
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Affiliation(s)
- Makoto Taniguchi
- Department of Life Science, Medical Research Institute, Kanazawa Medical University, Kahoku, Japan
| | - Toshiro Okazaki
- Research Institute for Bioresources and Biotechnology, Kanazawa Prefectural University, Nonoichi, Japan
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16
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Discovery of 1,8-naphthyridin-2-one derivative as a potent and selective sphingomyelin synthase 2 inhibitor. Bioorg Med Chem 2020; 28:115376. [DOI: 10.1016/j.bmc.2020.115376] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 02/01/2020] [Accepted: 02/06/2020] [Indexed: 12/21/2022]
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17
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Hirabayashi Y, Kim YJ. Roles of GPRC5 family proteins: focusing on GPRC5B and lipid-mediated signalling. J Biochem 2020; 167:541-547. [DOI: 10.1093/jb/mvaa030] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 02/26/2020] [Indexed: 12/15/2022] Open
Abstract
Abstract
In the past decade, physiological roles and molecular functions of GPRC5 family receptors, originally identified as retinoic acid-induced gene products, have been uncovered, even though their intrinsic agonists are still a mystery. They are differentially distributed in certain tissues and cells in the body suggesting that cell-type-specific regulations and functions are significant. Molecular biological approaches and knockout mouse studies reveal that GPRC5 family proteins have pivotal roles in cancer progression and control of metabolic homeostasis pathways. Remarkably, GPRC5B-mediated tyrosine-phosphorylation signalling cascades play a critical role in development of obesity and insulin resistance through dynamic sphingolipid metabolism.
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Affiliation(s)
| | - Yeon-Jeong Kim
- Department of Biochemistry, Faculty of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
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18
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Funcke JB, Scherer PE. Beyond adiponectin and leptin: adipose tissue-derived mediators of inter-organ communication. J Lipid Res 2019; 60:1648-1684. [PMID: 31209153 PMCID: PMC6795086 DOI: 10.1194/jlr.r094060] [Citation(s) in RCA: 176] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 06/17/2019] [Indexed: 01/10/2023] Open
Abstract
The breakthrough discoveries of leptin and adiponectin more than two decades ago led to a widespread recognition of adipose tissue as an endocrine organ. Many more adipose tissue-secreted signaling mediators (adipokines) have been identified since then, and much has been learned about how adipose tissue communicates with other organs of the body to maintain systemic homeostasis. Beyond proteins, additional factors, such as lipids, metabolites, noncoding RNAs, and extracellular vesicles (EVs), released by adipose tissue participate in this process. Here, we review the diverse signaling mediators and mechanisms adipose tissue utilizes to relay information to other organs. We discuss recently identified adipokines (proteins, lipids, and metabolites) and briefly outline the contributions of noncoding RNAs and EVs to the ever-increasing complexities of adipose tissue inter-organ communication. We conclude by reflecting on central aspects of adipokine biology, namely, the contribution of distinct adipose tissue depots and cell types to adipokine secretion, the phenomenon of adipokine resistance, and the capacity of adipose tissue to act both as a source and sink of signaling mediators.
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Affiliation(s)
- Jan-Bernd Funcke
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX
| | - Philipp E Scherer
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX
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19
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Dludla PV, Mazibuko-Mbeje SE, Nyambuya TM, Mxinwa V, Tiano L, Marcheggiani F, Cirilli I, Louw J, Nkambule BB. The beneficial effects of N-acetyl cysteine (NAC) against obesity associated complications: A systematic review of pre-clinical studies. Pharmacol Res 2019; 146:104332. [DOI: 10.1016/j.phrs.2019.104332] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 06/13/2019] [Accepted: 06/25/2019] [Indexed: 12/29/2022]
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20
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Potential therapeutic targets for atherosclerosis in sphingolipid metabolism. Clin Sci (Lond) 2019; 133:763-776. [PMID: 30890654 PMCID: PMC6422862 DOI: 10.1042/cs20180911] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 02/13/2019] [Accepted: 02/14/2019] [Indexed: 12/14/2022]
Abstract
Sphingolipids, such as sphingomyelins, ceramides, glycosphingolipids, and sphingosine-1-phosphates (S1P) are a large group of structurally and functionally diverse molecules. Some specific species are found associated with atherogenesis and provide novel therapeutic targets. Herein, we briefly review how sphingolipids are implicated in the progression of atherosclerosis and related diseases, and then we discuss the potential therapy options by targetting several key enzymes in sphingolipid metabolism.
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21
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Discovery, synthesis and anti-atherosclerotic activities of a novel selective sphingomyelin synthase 2 inhibitor. Eur J Med Chem 2018; 163:864-882. [PMID: 30580239 DOI: 10.1016/j.ejmech.2018.12.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 12/11/2018] [Accepted: 12/12/2018] [Indexed: 02/03/2023]
Abstract
The sphingomyelin synthase 2 (SMS2) is a potential target for pharmacological intervention in atherosclerosis. However, so far, few selective SMS2 inhibitors and their pharmacological activities were reported. In this study, a class of 2-benzyloxybenzamides were discovered as novel SMS2 inhibitors through scaffold hopping and structural optimization. Among them, Ly93 as one of the most potent inhibitors exhibited IC50 values of 91 nM and 133.9 μM against purified SMS2 and SMS1 respectively. The selectivity ratio of Ly93 was more than 1400-fold for purified SMS2 over SMS1. The in vitro studies indicated that Ly93 not only dose-dependently diminished apoB secretion from Huh7 cells, but also significantly reduced the SMS activity and increased cholesterol efflux from macrophages. Meanwhile, Ly93 inhibited the secretion of LPS-mediated pro-inflammatory cytokine and chemokine in macrophages. The pharmacokinetic profiles of Ly93 performed on C57BL/6J mice demonstrated that Ly93 was orally efficacious. As a potent selective SMS2 inhibitor, Ly93 significantly decreased the plasma SM levels of C57BL/6J mice. Furthermore, Ly93 was capable of dose-dependently attenuating the atherosclerotic lesions in the root and the entire aorta as well as macrophage content in lesions, in apolipoprotein E gene knockout mice treated with Ly93. In conclusion, we discovered a novel selective SMS2 inhibitor Ly93 and demonstrated its anti-atherosclerotic activities in vivo. The preliminary molecular mechanism-of-action studies revealed its function in lipid homeostasis and inflammation process, which indicated that the selective inhibition of SMS2 would be a promising treatment for atherosclerosis.
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22
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Lambert JM, Anderson AK, Cowart LA. Sphingolipids in adipose tissue: What's tipping the scale? Adv Biol Regul 2018; 70:19-30. [PMID: 30473005 PMCID: PMC11129658 DOI: 10.1016/j.jbior.2018.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/13/2018] [Accepted: 10/14/2018] [Indexed: 01/06/2023]
Abstract
Adipose tissue lies at the heart of obesity, mediating its many effects upon the rest of the body, with its unique capacity to expand and regenerate, throughout the lifespan of the organism. Adipose is appreciated as an endocrine organ, with its myriad adipokines that elicit both physiological and pathological outcomes. Sphingolipids, bioactive signaling molecules, affect many aspects of obesity and the metabolic syndrome. While sphingolipids are appreciated in the context of these diseases in other tissues, there are many discoveries yet to be uncovered in the adipose tissue. This review focuses on the effects of sphingolipids on various aspects of adipose function and dysfunction. The processes of adipogenesis, metabolism and thermogenesis, in addition to inflammation and insulin resistance are intimately linked to sphingolipids as discussed below.
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Affiliation(s)
- Johana M Lambert
- Department of Biochemistry and Molecular Biology and the Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA; Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Andrea K Anderson
- Department of Biochemistry and Molecular Biology and the Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA; Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - L Ashley Cowart
- Department of Biochemistry and Molecular Biology and the Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA; Hunter Holmes McGuire Veteran's Affairs Medical Center, Richmond, VA, USA.
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23
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GPRC5B-Mediated Sphingomyelin Synthase 2 Phosphorylation Plays a Critical Role in Insulin Resistance. iScience 2018; 8:250-266. [PMID: 30343189 PMCID: PMC6197706 DOI: 10.1016/j.isci.2018.10.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/09/2018] [Accepted: 10/01/2018] [Indexed: 12/20/2022] Open
Abstract
GPRC5B recruitment of Src family kinases has been implicated in diet-induced insulin resistance. However, the mechanism of this action is not fully understood. Here, we report that GPRC5B-mediated phosphorylation of sphingomyelin synthase 2 (SMS2) by Fyn is a crucial step in the development of insulin resistance. Lipid-induced metabolic stress augments SMS2 phosphorylation by facilitating the interaction of GPRC5B and SMS2. SMS2 phosphorylation reduces its ubiquitination, and consequently increases SMS2 protein abundance. Although ceramide and diacylglycerol (DAG) have been known to be central mediators of lipid-induced insulin resistance, the accumulation of these lipids fails to impair insulin signaling in SMS2 knockout mouse embryonic fibroblasts (MEFs). Conversely, exogenous expression of a phosphomimetic SMS2 impairs insulin action in SMS2 knockout MEFs under metabolic stress conditions. We demonstrate that SMS2-generated DAG in sphingomyelin synthesis inhibits insulin signaling through JNK activation. Thus, GPRC5B links sphingolipid metabolism to diet-induced insulin resistance via SMS2-dependent DAG production. Saturated fatty acids enhance interaction between GPRC5B and SMS2 GPRC5B facilitates tyrosine phosphorylation of SMS2 by recruiting Fyn Tyrosine phosphorylation of SMS2 increases its protein abundance SMS2-generated DAG is critical for the development of insulin resistance
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24
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Abstract
Studies of bioactive lipids in general and sphingolipids in particular have intensified over the past several years, revealing an unprecedented and unanticipated complexity of the lipidome and its many functions, which rivals, if not exceeds, that of the genome or proteome. These results highlight critical roles for bioactive sphingolipids in most, if not all, major cell biological responses, including all major cell signalling pathways, and they link sphingolipid metabolism to key human diseases. Nevertheless, the fairly nascent field of bioactive sphingolipids still faces challenges in its biochemical and molecular underpinnings, including defining the molecular mechanisms of pathway and enzyme regulation, the study of lipid-protein interactions and the development of cellular probes, suitable biomarkers and therapeutic approaches.
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Affiliation(s)
- Yusuf A Hannun
- Stony Brook Cancer Center and Department of Medicine, Stony Brook University, New York 11794, USA
| | - Lina M Obeid
- Stony Brook Cancer Center and Department of Medicine, Stony Brook University, New York 11794, USA
- Northport Veterans Affairs Medical Center, Northport, New York 11768, USA
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25
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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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26
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Chen Y, Cao Y. The sphingomyelin synthase family: proteins, diseases, and inhibitors. Biol Chem 2017; 398:1319-1325. [PMID: 28742512 DOI: 10.1515/hsz-2017-0148] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/13/2017] [Indexed: 12/18/2022]
Abstract
Sphingomyelin (SM) is among the most important biomolecules in eukaryotes and acts as both constructive components and signal carrier in physiological processes. SM is catalyzed by a membrane protein family, sphingomyelin synthases (SMSs), consisting of three members, SMS1, SMS2 and SMSr. SMSs modulate sphingomyelin and other sphingolipids levels, thereby regulating membrane mobility, ceramide-dependent apoptosis and DAG-dependent signaling pathways. SMSs was found associated with various diseases. Downregulation of SMS2 activity results in protective effects against obesity, atherosclerosis and diabetes and makes SMS2 inhibitors potential medicines. Structural guided specific drug design could be the next breakthrough, discriminating SMS2 from other homologs.
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27
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The expanding role of sphingolipids in lipid droplet biogenesis. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1155-1165. [PMID: 28743537 DOI: 10.1016/j.bbalip.2017.07.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 07/18/2017] [Accepted: 07/18/2017] [Indexed: 01/17/2023]
Abstract
Sphingolipids are a diverse class of lipids that have regulatory, structural, and metabolic functions. Although chemically distinct from the neutral lipids and the glycerophospholipids, which are the main lipid components of the lipid droplets, sphingolipids have nonetheless been shown to influence lipid droplet formation. The goal of this article is to review the available information and provide a cohesive picture of the role sphingolipids play in lipid droplet biogenesis. The following topics are discussed: (i) the abundance of sphingolipids in lipid droplets and their functional significance; (ii) cross-talk between the synthetic pathways of sphingolipids, glycerophospholipids, and neutral lipids; (iii) the impact of bioactive sphingolipids on TAG synthesis and degradation; (iv) interactions between sphingolipids and other lipid droplet components, like cholesterol esters and proteins; (v) inhibition/genetic deletion of specific sphingolipid metabolic enzymes and the resulting effects on lipid droplet formation in mouse models. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink.
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28
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Abstract
Lipidomics is the identification and quantitation of changes in the lipidome of a cell, tissue, organ or biofluid in health and disease using high resolution mass spectrometry. Lipidome of a particular organism has relevance to the disease manifestation as it reflects the metabolic changes which can be a consequence of the disease. Hence these changes in the molecules can be considered as potential markers for screening and early detection of the disease. Biological fluids as blood/serum/plasma, urine, saliva, tear and cerebrospinal fluid, due to their accessibility, offer ease of collection with minimal or no discomfort to the patient and provide a ready footprint of the metabolic changes occurring during disease. This review provides a brief introduction to lipidomics and its role in understanding the metabolic changes in health and disease followed by discussion on the chemical diversity of the lipid species and their biological role, mammalian lipids and their metabolism and role of lipids in pathogens and the immune response before dwelling further into importance of studying lipidome in various biological fluids. The challenges in performing a lipidomic analysis at the experimental and data analysis stages are discussed.
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Affiliation(s)
- Arkasubhra Ghosh
- GROW Research Laboratory, Narayana Nethralaya Foundation, Narayana Health City, # 258/A, Bommasandra, Hosur Road, Bangalore, 560 099, India
| | - Krishnatej Nishtala
- GROW Research Laboratory, Narayana Nethralaya Foundation, Narayana Health City, # 258/A, Bommasandra, Hosur Road, Bangalore, 560 099, India.
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29
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30
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Yano M. ABCB10 depletion reduces unfolded protein response in mitochondria. Biochem Biophys Res Commun 2017; 486:465-469. [PMID: 28315685 DOI: 10.1016/j.bbrc.2017.03.063] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 03/14/2017] [Indexed: 10/20/2022]
Abstract
Mitochondria have many functions, including ATP generation. The electron transport chain (ETC) and the coupled ATP synthase generate ATP by consuming oxygen. Reactive oxygen species (ROS) are also produced by ETC, and ROS damage deoxyribonucleic acids, membrane lipids and proteins. Recent analysis indicate that mitochondrial unfolded protein response (UPRmt), which enhances expression of mitochondrial chaperones and proteases to remove damaged proteins, is activated when damaged proteins accumulate in the mitochondria. In Caenorhabditis elegans, HAF-1, a putative ortholog of human ABCB10, plays an essential role in signal transduction from mitochondria to nuclei to enhance UPRmt. Therefore, it is possible that ABCB10 has a role similar to that of HAF-1. However, it has not been reported whether ABCB10 is a factor in the signal transduction pathway to enhance UPRmt. In this study, ABCB10 was depleted in HepG2 cells using small interfering RNA (siRNA), and the effect was examined. ABCB10 depletion upregulated ROS and the expression of ROS-detoxifying enzymes (SOD2, GSTA1, and GSTA2), and SESN3, a protein induced by ROS to protect the cell from oxidative stress. In addition, ABCB10 depletion significantly decreased expression of UPRmt-related mitochondrial chaperones (HSPD1 and DNAJA3), and a mitochondrial protease (LONP1). However, the putative activity of ABCB10 to export peptides from mitochondria was not lost by ABCB10 depletion. Altogether, these data suggest that ABCB10 is involved in UPRmt signaling pathway similar to that of HAF-1, although ABCB10 probably does not participate in peptide export from mitochondria.
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Affiliation(s)
- Masato Yano
- Department of Medical Technology, Faculty of Health Sciences, Kumamoto Health Science University, Kumamoto 861-5598, Japan.
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Cabukusta B, Kol M, Kneller L, Hilderink A, Bickert A, Mina JGM, Korneev S, Holthuis JCM. ER residency of the ceramide phosphoethanolamine synthase SMSr relies on homotypic oligomerization mediated by its SAM domain. Sci Rep 2017; 7:41290. [PMID: 28120887 PMCID: PMC5264588 DOI: 10.1038/srep41290] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 12/19/2016] [Indexed: 12/12/2022] Open
Abstract
SMSr/SAMD8 is an ER-resident ceramide phosphoethanolamine synthase with a critical role in controlling ER ceramides and suppressing ceramide-induced apoptosis in cultured cells. SMSr-mediated ceramide homeostasis relies on the enzyme's catalytic activity as well as on its N-terminal sterile α-motif or SAM domain. Here we report that SMSr-SAM is structurally and functionally related to the SAM domain of diacylglycerol kinase DGKδ, a central regulator of lipid signaling at the plasma membrane. Native gel electrophoresis indicates that both SAM domains form homotypic oligomers. Chemical crosslinking studies show that SMSr self-associates into ER-resident trimers and hexamers that resemble the helical oligomers formed by DGKδ-SAM. Residues critical for DGKδ-SAM oligomerization are conserved in SMSr-SAM and their substitution causes a dissociation of SMSr oligomers as well as a partial redistribution of the enzyme to the Golgi. Conversely, treatment of cells with curcumin, a drug disrupting ceramide and Ca2+ homeostasis in the ER, stabilizes SMSr oligomers and promotes retention of the enzyme in the ER. Our data provide first demonstration of a multi-pass membrane protein that undergoes homotypic oligomerization via its SAM domain and indicate that SAM-mediated self-assembly of SMSr is required for efficient retention of the enzyme in the ER.
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Affiliation(s)
- Birol Cabukusta
- Molecular Cell Biology Division, Faculty of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Matthijs Kol
- Molecular Cell Biology Division, Faculty of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Laura Kneller
- Molecular Cell Biology Division, Faculty of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Angelika Hilderink
- Molecular Cell Biology Division, Faculty of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Andreas Bickert
- Molecular Genetics, Life and Medical Sciences Institute, University of Bonn, 53115 Bonn, Germany
| | - John G. M. Mina
- Molecular Cell Biology Division, Faculty of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Sergei Korneev
- Molecular Cell Biology Division, Faculty of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Joost C. M. Holthuis
- Molecular Cell Biology Division, Faculty of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
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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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Characterization of the role of sphingomyelin synthase 2 in glucose metabolism in whole-body and peripheral tissues in mice. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:688-702. [DOI: 10.1016/j.bbalip.2016.04.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 04/20/2016] [Accepted: 04/30/2016] [Indexed: 11/22/2022]
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34
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Adada M, Luberto C, Canals D. Inhibitors of the sphingomyelin cycle: Sphingomyelin synthases and sphingomyelinases. Chem Phys Lipids 2016. [DOI: 10.1016/j.chemphyslip.2015.07.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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35
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Yoshizaki H, Ogiso H, Okazaki T, Kiyokawa E. Comparative lipid analysis in the normal and cancerous organoids of MDCK cells. J Biochem 2016; 159:573-84. [PMID: 26783265 DOI: 10.1093/jb/mvw001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 12/06/2015] [Indexed: 11/14/2022] Open
Abstract
Epithelial organs are made of a well-polarized monolayer of epithelial cells, and their morphology is maintained strictly for their proper functioning. The roles of lipids are not only to generate the membrane, but also to provide the specific domains for signal transduction, or to transmit signals as second messengers. By using a liquid chromatography-electrospray ionization mass spectrometry (LC-MS)/MS method, we here analyzed sphingolipids in MDCK cysts under various conditions. Our result showed that, compared to the three-dimensional cyst, the two-dimensional MDCK sheet is relatively enriched in sphingolipids. During cystogenesis, the contents of sphingomyelin (SM) and lactocylceramide (LacCer)-but, none those of ceramide, hexocylceramide, or GM3-are altered depending on their acyl chains. While the total SM is decreased more efficiently by SMS-1 knockdown than by SMS-2 knockdown, depletion of SMS-2, but not SMS-1, inhibits cyst growth. Finally upon the switching on of activated K-Ras expression which induces luminal cell filling, ceramide and LacCer are increased. Our parallel examinations of the microarray data for mRNA of sphingolipid metabolic enzymes failed to fully explain the remodelling of the sphingolipids of MDCK cysts. However, these results should be useful to investigate the cell-type- and structure-specific lipid metabolism.
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Affiliation(s)
| | - Hideo Ogiso
- Department of Hematology/Immunology, Kanazawa Medical University, Ishikawa 920-0293, Japan
| | - Toshiro Okazaki
- Department of Hematology/Immunology, Kanazawa Medical University, Ishikawa 920-0293, Japan
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36
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Lipodystrophies: adipose tissue disorders with severe metabolic implications. J Physiol Biochem 2015; 71:471-8. [DOI: 10.1007/s13105-015-0404-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 03/18/2015] [Indexed: 01/06/2023]
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37
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Bickert A, Ginkel C, Kol M, vom Dorp K, Jastrow H, Degen J, Jacobs RL, Vance DE, Winterhager E, Jiang XC, Dörmann P, Somerharju P, Holthuis JCM, Willecke K. Functional characterization of enzymes catalyzing ceramide phosphoethanolamine biosynthesis in mice. J Lipid Res 2015; 56:821-35. [PMID: 25667419 DOI: 10.1194/jlr.m055269] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Besides bulk amounts of SM, mammalian cells produce small quantities of the SM analog ceramide phosphoethanolamine (CPE). Little is known about the biological role of CPE or enzymes responsible for CPE production. Heterologous expression studies revealed that SM synthase (SMS)2 is a bifunctional enzyme producing both SM and CPE, whereas SMS-related protein (SMSr) serves as monofunctional CPE synthase. Acute disruption of SMSr catalytic activity in cultured cells causes a rise in endoplasmic reticulum (ER) ceramides, fragmentation of ER exit sites, and induction of mitochondrial apoptosis. To address the relevance of CPE biosynthesis in vivo, we analyzed the tissue-specific distribution of CPE in mice and generated mouse lines lacking SMSr and SMS2 catalytic activity. We found that CPE levels were >300-fold lower than SM in all tissues examined. Unexpectedly, combined inactivation of SMSr and SMS2 significantly reduced, but did not eliminate, tissue-specific CPE pools and had no obvious impact on mouse development or fertility. While SMSr is widely expressed and serves as the principal CPE synthase in the brain, blocking its catalytic activity did not affect ceramide levels or secretory pathway integrity in the brain or any other tissue. Our data provide a first inventory of CPE species and CPE-biosynthetic enzymes in mammals.
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Affiliation(s)
- Andreas Bickert
- Molecular Genetics, Life, and Medical Sciences Institute University of Bonn, 53115 Bonn, Germany
| | - Christina Ginkel
- Molecular Genetics, Life, and Medical Sciences Institute University of Bonn, 53115 Bonn, Germany
| | - Matthijs Kol
- Molecular Cell Biology Division, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Katharina vom Dorp
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany
| | - Holger Jastrow
- Imaging Center Essen, Electron Microscopy Unit, University Hospital University of Duisburg-Essen, 45147 Essen, Germany
| | - Joachim Degen
- Molecular Genetics, Life, and Medical Sciences Institute University of Bonn, 53115 Bonn, Germany
| | - René L Jacobs
- Departments of Agricultural, Food, and Nutritional Science, Molecular and Cell Biology of Lipids, University of Alberta, T6G 2S2 Edmonton, Canada
| | - Dennis E Vance
- Biochemistry, University of Alberta, T6G 2S2 Edmonton, Canada
| | - Elke Winterhager
- Department of Molecular Biology, University of Duisburg-Essen, 45147 Essen, Germany
| | - Xian-Cheng Jiang
- Department of Anatomy and Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY 11203
| | - Peter Dörmann
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany
| | - Pentti Somerharju
- Medical Biochemistry, Institute of Biomedicine, University of Helsinki, 00014 Helsinki, Finland
| | - Joost C M Holthuis
- Molecular Cell Biology Division, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Klaus Willecke
- Molecular Genetics, Life, and Medical Sciences Institute University of Bonn, 53115 Bonn, Germany
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38
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Ferreira AVM, Menezes-Garcia Z, Viana JB, Mário ÉG, Botion LM. Distinct metabolic pathways trigger adipocyte fat accumulation induced by high-carbohydrate and high-fat diets. Nutrition 2014; 30:1138-43. [DOI: 10.1016/j.nut.2014.02.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 02/13/2014] [Accepted: 02/14/2014] [Indexed: 10/25/2022]
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39
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Ndisang JF, Tiwari S. Featured article: induction of heme oxygenase with hemin improves pericardial adipocyte morphology and function in obese Zucker rats by enhancing proteins of regeneration. Exp Biol Med (Maywood) 2014; 240:45-57. [PMID: 25053781 DOI: 10.1177/1535370214544268] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Oxidative stress and inflammation are implicated in tissue remodeling, hypertrophy, and organ malfunction. Since heme-oxygenase (HO) is a cytoprotective enzyme with effects against oxidative stress and inflammation, we investigated the effects of upregulating HO with hemin on adipocyte hypertrophy, proteins of repair/regeneration including beta-catenin, Oct3/4 and Pax2 as well as pro-fibrotic/remodeling proteins like osteopontin and transforming growth factor-beta (TGF-β) in pericardial adipose tissue from obese Zucker rats (ZRs). Treatment with hemin significantly reduced pericardial adipose tissue inflammation/oxidative stress, suppressed osteopontin and TGF-β, and attenuated pericardial adipocyte hypertrophy in obese ZRs. These were associated with enhanced expression of the stem/progenitor-cell marker cKit; the potentiation of several proteins of regeneration including beta-catenin, Oct3/4, Pax2; and improved pericardial adipocyte morphology. Interestingly, the amelioration of adipocyte hypertrophy in hemin-treated animals was accompanied by improved adipocyte function, evidenced by increased levels of pericardial adipose tissue adiponectin. Furthermore, hemin significantly reduced hypertriglyceridemia and hypercholesteromia in obese ZRs. The protective effects of hemin were accompanied by robust potentiation HO activity and the total antioxidant capacity, whereas the co-administration of hemin with the HO inhibitor, stannous mesoporphyrin abolished the effects of hemin. These data suggest that hemin improves pericardial adipocyte morphology and function by enhancing proteins of repair and regeneration, while concomitantly abating inflammatory/oxidative insults and suppressing extracellular-matrix/profibrotic and remodeling proteins. The reduction of hypertriglyceridemia, hypercholesteromia, pericardial adiposity, and pericardial adipocyte hypertrophy with corresponding improvement of adipocyte morphology/function in hemin-treated animals suggests that HO inducers may be explored for the design of novel remedies against cardiac complications arising from excessive adiposity.
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Affiliation(s)
- Joseph Fomusi Ndisang
- Department of Physiology, College of Medicine, University of Saskatchewan College of Medicine, Saskatoon, SK, Canada S7N 5E5
| | - Shuchita Tiwari
- Department of Physiology, College of Medicine, University of Saskatchewan College of Medicine, Saskatoon, SK, Canada S7N 5E5
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40
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Taniguchi M, Okazaki T. The role of sphingomyelin and sphingomyelin synthases in cell death, proliferation and migration—from cell and animal models to human disorders. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:692-703. [DOI: 10.1016/j.bbalip.2013.12.003] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 12/06/2013] [Accepted: 12/09/2013] [Indexed: 12/16/2022]
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