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Al Harake SN, Abedin Y, Hatoum F, Nassar NZ, Ali A, Nassar A, Kanaan A, Bazzi S, Azar S, Harb F, Ghadieh HE. Involvement of a battery of investigated genes in lipid droplet pathophysiology and associated comorbidities. Adipocyte 2024; 13:2403380. [PMID: 39329369 DOI: 10.1080/21623945.2024.2403380] [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: 12/07/2023] [Revised: 08/29/2024] [Accepted: 09/05/2024] [Indexed: 09/28/2024] Open
Abstract
Lipid droplets (LDs) are highly specialized energy storage organelles involved in the maintenance of lipid homoeostasis by regulating lipid flux within white adipose tissue (WAT). The physiological function of adipocytes and LDs can be compromised by mutations in several genes, leading to NEFA-induced lipotoxicity, which ultimately manifests as metabolic complications, predominantly in the form of dyslipidemia, ectopic fat accumulation, and insulin resistance. In this review, we delineate the effects of mutations and deficiencies in genes - CIDEC, PPARG, BSCL2, AGPAT2, PLIN1, LIPE, LMNA, CAV1, CEACAM1, and INSR - involved in lipid droplet metabolism and their associated pathophysiological impairments, highlighting their roles in the development of lipodystrophies and metabolic dysfunction.
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Affiliation(s)
- Sami N Al Harake
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Yasamin Abedin
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Fatema Hatoum
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Nour Zahraa Nassar
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Ali Ali
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Aline Nassar
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Amjad Kanaan
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Samer Bazzi
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Sami Azar
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Frederic Harb
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
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McClure JJ, McIlroy GD, Symons RA, Clark SM, Cunningham I, Han W, Kania K, Colella F, Rochford JJ, De Bari C, Roelofs AJ. Disentangling the detrimental effects of local from systemic adipose tissue dysfunction on articular cartilage in the knee. Osteoarthritis Cartilage 2024:S1063-4584(24)01312-8. [PMID: 39103079 DOI: 10.1016/j.joca.2024.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 07/11/2024] [Accepted: 07/12/2024] [Indexed: 08/07/2024]
Abstract
OBJECTIVE Obesity increases osteoarthritis (OA) risk due to adipose tissue dysfunction with associated metabolic syndrome and excess weight. Lipodystrophy syndromes exhibit systemic metabolic and inflammatory abnormalities similar to obesity without biomechanical overloading. Here, we used lipodystrophy mouse models to investigate the effects of systemic versus intra-articular adipose tissue dysfunction on the knee. METHODS Intra-articular adipose tissue development was studied using reporter mice. Mice with selective lipodystrophy of intra-articular adipose tissue were generated by conditional knockout (cKO) of Bscl2 in Gdf5-lineage cells, and compared with whole-body Bscl2 knockout (KO) mice with generalised lipodystrophy and associated systemic metabolic dysfunction. OA was induced by surgically destabilising the medial meniscus (DMM) and obesity by high-fat diet (HFD). Gene expression was analysed by quantitative RT-PCR and tissues were analysed histologically. RESULTS The infrapatellar fat pad (IFP), in contrast to overlying subcutaneous adipose tissue, developed from a template established from the Gdf5-expressing joint interzone during late embryogenesis, and was populated shortly after birth by adipocytes stochastically arising from Pdgfrα-expressing Gdf5-lineage progenitors. While female Bscl2 KO mice with generalised lipodystrophy developed spontaneous knee cartilage damage, Bscl2 cKO mice with intra-articular lipodystrophy did not, despite the presence of synovial hyperplasia and inflammation of the residual IFP. Furthermore, male Bscl2 cKO mice showed no worse cartilage damage after DMM. However, female Bscl2 cKO mice showed increased susceptibility to the cartilage-damaging effects of HFD-induced obesity. CONCLUSION Our findings emphasise the prevalent role of systemic metabolic and inflammatory effects in impairing cartilage homeostasis, with a modulatory role for intra-articular adipose tissue.
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Affiliation(s)
- Jessica J McClure
- Arthritis & Regenerative Medicine Laboratory, Centre for Arthritis and Musculoskeletal Health, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - George D McIlroy
- The Rowett Institute and Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Rebecca A Symons
- Arthritis & Regenerative Medicine Laboratory, Centre for Arthritis and Musculoskeletal Health, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Susan M Clark
- Arthritis & Regenerative Medicine Laboratory, Centre for Arthritis and Musculoskeletal Health, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Iain Cunningham
- Arthritis & Regenerative Medicine Laboratory, Centre for Arthritis and Musculoskeletal Health, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Weiping Han
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A⁎STAR), Singapore
| | - Karolina Kania
- Arthritis & Regenerative Medicine Laboratory, Centre for Arthritis and Musculoskeletal Health, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Fabio Colella
- Arthritis & Regenerative Medicine Laboratory, Centre for Arthritis and Musculoskeletal Health, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Justin J Rochford
- The Rowett Institute and Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Cosimo De Bari
- Arthritis & Regenerative Medicine Laboratory, Centre for Arthritis and Musculoskeletal Health, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Anke J Roelofs
- Arthritis & Regenerative Medicine Laboratory, Centre for Arthritis and Musculoskeletal Health, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK.
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Li C, Sun XN, Funcke JB, Vanharanta L, Joffin N, Li Y, Prasanna X, Paredes M, Joung C, Gordillo R, Vörös C, Kulig W, Straub L, Chen S, Velasco J, Cobb A, Padula DL, Wang MY, Onodera T, Varlamov O, Li Y, Liu C, Nawrocki AR, Zhao S, Oh DY, Wang ZV, Goodman JM, Wynn RM, Vattulainen I, Han Y, Ikonen E, Scherer PE. Adipogenin Dictates Adipose Tissue Expansion by Facilitating the Assembly of a Dodecameric Seipin Complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.25.605195. [PMID: 39211078 PMCID: PMC11360994 DOI: 10.1101/2024.07.25.605195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Adipogenin (Adig) is an evolutionarily conserved microprotein and is highly expressed in adipose tissues and testis. Here, we identify Adig as a critical regulator for lipid droplet formation in adipocytes. We determine that Adig interacts directly with seipin, leading to the formation of a rigid complex. We solve the structure of the seipin/Adig complex by Cryo-EM at 2.98Å overall resolution. Surprisingly, seipin can form two unique oligomers, undecamers and dodecamers. Adig selectively binds to the dodecameric seipin complex. We further find that Adig promotes seipin assembly by stabilizing and bridging adjacent seipin subunits. Functionally, Adig plays a key role in generating lipid droplets in adipocytes. In mice, inducible overexpression of Adig in adipocytes substantially increases fat mass, with enlarged lipid droplets. It also elevates thermogenesis during cold exposure. In contrast, inducible adipocyte-specific Adig knockout mice manifest aberrant lipid droplet formation in brown adipose tissues and impaired cold tolerance.
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Liu J, Li L, Xu D, Li Y, Chen T, Liu Y, Bao Y, Wang Y, Yang L, Li P, Xu L. Rab18 maintains homeostasis of subcutaneous adipose tissue to prevent obesity-induced metabolic disorders. SCIENCE CHINA. LIFE SCIENCES 2024; 67:1170-1182. [PMID: 38523235 DOI: 10.1007/s11427-023-2367-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 05/15/2023] [Indexed: 03/26/2024]
Abstract
Metabolically healthy obesity refers to obese individuals who do not develop metabolic disorders. These people store fat in subcutaneous adipose tissue (SAT) rather than in visceral adipose tissue (VAT). However, the molecules participating in this specific scenario remain elusive. Rab18, a lipid droplet (LD)-associated protein, mediates the contact between the endoplasmic reticulum (ER) and LDs to facilitate LD growth and maturation. In the present study, we show that the protein level of Rab18 is specifically upregulated in the SAT of obese people and mice. Rab18 adipocyte-specific knockout (Rab18 AKO) mice had a decreased volume ratio of SAT to VAT compared with wildtype mice. When subjected to high-fat diet (HFD), Rab18 AKO mice had increased ER stress and inflammation, reduced adiponectin, and decreased triacylglycerol (TAG) accumulation in SAT. In contrast, TAG accumulation in VAT, brown adipose tissue (BAT) or liver of Rab18 AKO mice had a moderate increase without ER stress stimulation. Rab18 AKO mice developed insulin resistance and systematic inflammation. Rab18 AKO mice maintained body temperature in response to acute and chronic cold induction with a thermogenic SAT, similar to the counterpart mice. Furthermore, Rab18-deficient 3T3-L1 adipocytes were more prone to palmitate-induced ER stress, indicating the involvement of Rab18 in alleviating lipid toxicity. Rab18 AKO mice provide a good animal model to investigate metabolic disorders such as impaired SAT. In conclusion, our studies reveal that Rab18 is a key and specific regulator that maintains the proper functions of SAT by alleviating lipid-induced ER stress.
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Affiliation(s)
- Jiaming Liu
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Shanghai Qi Zhi Institute, Shanghai, 200232, China
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, 200438, China
| | - Liangkui Li
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tianjian Laboratory of Advanced Biomedical Sciences, Zhengzhou University, Zhengzhou, 450001, China
| | - Dijin Xu
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yuqi Li
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Tao Chen
- Department of Physiology, School of Basic Medical Sciences, Gannan Medical University, Ganzhou, 341000, China
| | - Yeyang Liu
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yuqian Bao
- Department of Endocrinology and Metabolism, Shanghai Jiao Tong University School of Medicine Affiliated Sixth People's Hospital, Shanghai, 200025, China
| | - Yan Wang
- Center for Endocrine Metabolism and Immune Diseases, Beijing Luhe Hospital, Capital Medical University, Beijing, 101149, China
- Beijing Key Laboratory of Diabetes Research and Care, Beijing, 101149, China
| | - Longyan Yang
- Center for Endocrine Metabolism and Immune Diseases, Beijing Luhe Hospital, Capital Medical University, Beijing, 101149, China
- Beijing Key Laboratory of Diabetes Research and Care, Beijing, 101149, China
| | - Peng Li
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
- Shanghai Qi Zhi Institute, Shanghai, 200232, China.
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, 200438, China.
- Tianjian Laboratory of Advanced Biomedical Sciences, Zhengzhou University, Zhengzhou, 450001, China.
| | - Li Xu
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
- Shanghai Qi Zhi Institute, Shanghai, 200232, China.
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Cui W, Yang J, Tu C, Zhang Z, Zhao H, Qiao Y, Li Y, Yang W, Lim KL, Ma Q, Zhang C, Lu L. Seipin deficiency-induced lipid dysregulation leads to hypomyelination-associated cognitive deficits via compromising oligodendrocyte precursor cell differentiation. Cell Death Dis 2024; 15:350. [PMID: 38773070 PMCID: PMC11109229 DOI: 10.1038/s41419-024-06737-z] [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: 12/25/2023] [Revised: 05/05/2024] [Accepted: 05/09/2024] [Indexed: 05/23/2024]
Abstract
Seipin is one key mediator of lipid metabolism that is highly expressed in adipose tissues as well as in the brain. Lack of Seipin gene, Bscl2, leads to not only severe lipid metabolic disorders but also cognitive impairments and motor disabilities. Myelin, composed mainly of lipids, facilitates nerve transmission and is important for motor coordination and learning. Whether Seipin deficiency-leaded defects in learning and motor coordination is underlined by lipid dysregulation and its consequent myelin abnormalities remains to be elucidated. In the present study, we verified the expression of Seipin in oligodendrocytes (OLs) and their precursors, oligodendrocyte precursor cells (OPCs), and demonstrated that Seipin deficiency compromised OPC differentiation, which led to decreased OL numbers, myelin protein, myelinated fiber proportion and thickness of myelin. Deficiency of Seipin resulted in impaired spatial cognition and motor coordination in mice. Mechanistically, Seipin deficiency suppressed sphingolipid metabolism-related genes in OPCs and caused morphological abnormalities in lipid droplets (LDs), which markedly impeded OPC differentiation. Importantly, rosiglitazone, one agonist of PPAR-gamma, substantially restored phenotypes resulting from Seipin deficiency, such as aberrant LDs, reduced sphingolipids, obstructed OPC differentiation, and neurobehavioral defects. Collectively, the present study elucidated how Seipin deficiency-induced lipid dysregulation leads to neurobehavioral deficits via impairing myelination, which may pave the way for developing novel intervention strategy for treating metabolism-involved neurological disorders.
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Affiliation(s)
- Wenli Cui
- School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
- Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Jing Yang
- School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
- Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Chuanyun Tu
- School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
- Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Ziting Zhang
- School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
- Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Huifang Zhao
- School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Yan Qiao
- Analytical Instrumentation Center & State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, Shanxi, China
| | - Yanqiu Li
- Analytical Instrumentation Center & State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, Shanxi, China
| | - Wulin Yang
- Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China
| | - Kah-Leong Lim
- Lee Kong Chian School of Medicine, Nanyang Technological University, 11 Mandalay Road, Singapore, 308232, Singapore
| | - Quanhong Ma
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, China.
| | - Chengwu Zhang
- School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China.
- Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, 030001, Shanxi, China.
| | - Li Lu
- School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China.
- Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, 030001, Shanxi, China.
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Meng Z, Liu C, Xu M, Tao Y, Li H, Wang X, Liao J, Wang M. Adipose transplantation improves metabolism and atherosclerosis but not perivascular adipose tissue abnormality or vascular dysfunction in lipodystrophic Seipin/Apoe null mice. Am J Physiol Cell Physiol 2024; 326:C1410-C1422. [PMID: 38525541 PMCID: PMC11371364 DOI: 10.1152/ajpcell.00698.2023] [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: 12/17/2023] [Revised: 03/14/2024] [Accepted: 03/21/2024] [Indexed: 03/26/2024]
Abstract
Adipose dysfunction in lipodystrophic SEIPIN deficiency is associated with multiple metabolic disorders and increased risks of developing cardiovascular diseases, such as atherosclerosis, cardiac hypertrophy, and heart failure. Recently, adipose transplantation has been found to correct adipose dysfunction and metabolic disorders in lipodystrophic Seipin knockout mice; however, whether adipose transplantation could improve lipodystrophy-associated cardiovascular consequences is still unclear. Here, we aimed to explore the effects of adipose transplantation on lipodystrophy-associated metabolic cardiovascular diseases in Seipin knockout mice crossed into atherosclerosis-prone apolipoprotein E (Apoe) knockout background. At 2 months of age, lipodystrophic Seipin/Apoe double knockout mice and nonlipodystrophic Apoe knockout controls were subjected to adipose transplantation or sham operation. Seven months later, mice were euthanized. Our data showed that although adipose transplantation had no significant impact on endogenous adipose atrophy or gene expression, it remarkably increased plasma leptin but not adiponectin concentration in Seipin/Apoe double knockout mice. This led to significantly reduced hyperlipidemia, hepatic steatosis, and insulin resistance in Seipin/Apoe double knockout mice. Consequently, atherosclerosis burden, intraplaque macrophage infiltration, and aortic inflammatory gene expression were all attenuated in Seipin/Apoe double knockout mice with adipose transplantation. However, adipocyte morphology, macrophage infiltration, or fibrosis of the perivascular adipose tissue was not altered in Seipin/Apoe double knockout mice with adipose transplantation, followed by no significant improvement of vasoconstriction or relaxation. In conclusion, we demonstrate that adipose transplantation could alleviate lipodystrophy-associated metabolic disorders and atherosclerosis but has an almost null impact on perivascular adipose abnormality or vascular dysfunction in lipodystrophic Seipin/Apoe double knockout mice.NEW & NOTEWORTHY Adipose transplantation (AT) reverses multiply metabolic derangements in lipodystrophy, but whether it could improve lipodystrophy-related cardiovascular consequences is unknown. Here, using Seipin/Apoe double knockout mice as a lipodystrophy disease model, we showed that AT partially restored adipose functionality, which translated into significantly reduced atherosclerosis. However, AT was incapable of reversing perivascular adipose abnormality or vascular dysfunction. The current study provides preliminary experimental evidence on the therapeutic potential of AT on lipodystrophy-related metabolic cardiovascular diseases.
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Affiliation(s)
- Zhe Meng
- Department of Cardiology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Chuangxing Liu
- Department of Cardiology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Mengke Xu
- Department of Cardiology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Yongqiang Tao
- Department of Cardiology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Haiyu Li
- Department of Cardiology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Xijia Wang
- Department of Cardiology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Jiawei Liao
- Institute of Cardiovascular Diseases, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Mengyu Wang
- Department of Cardiology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
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Roumane A, Mcilroy GD, Sommer N, Han W, Heisler LK, Rochford JJ. GLP-1 receptor agonist improves metabolic disease in a pre-clinical model of lipodystrophy. Front Endocrinol (Lausanne) 2024; 15:1379228. [PMID: 38745956 PMCID: PMC11091257 DOI: 10.3389/fendo.2024.1379228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 04/08/2024] [Indexed: 05/16/2024] Open
Abstract
Aims Individuals with lipodystrophies typically suffer from metabolic disease linked to adipose tissue dysfunction including lipoatrophic diabetes. In the most severe forms of lipodystrophy, congenital generalised lipodystrophy, adipose tissue may be almost entirely absent. Better therapies for affected individuals are urgently needed. Here we performed the first detailed investigation of the effects of a glucagon like peptide-1 receptor (GLP-1R) agonist in lipoatrophic diabetes, using mice with generalised lipodystrophy. Methods Lipodystrophic insulin resistant and glucose intolerant seipin knockout mice were treated with the GLP-1R agonist liraglutide either acutely preceding analyses of insulin and glucose tolerance or chronically prior to metabolic phenotyping and ex vivo studies. Results Acute liraglutide treatment significantly improved insulin, glucose and pyruvate tolerance. Once daily injection of seipin knockout mice with liraglutide for 14 days led to significant improvements in hepatomegaly associated with steatosis and reduced markers of liver fibrosis. Moreover, liraglutide enhanced insulin secretion in response to glucose challenge with concomitantly improved glucose control. Conclusions GLP-1R agonist liraglutide significantly improved lipoatrophic diabetes and hepatic steatosis in mice with generalised lipodystrophy. This provides important insights regarding the benefits of GLP-1R agonists for treating lipodystrophy, informing more widespread use to improve the health of individuals with this condition.
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Affiliation(s)
- Ahlima Roumane
- The Rowett Institute and Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Aberdeen, United Kingdom
| | - George D. Mcilroy
- The Rowett Institute and Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Aberdeen, United Kingdom
| | - Nadine Sommer
- The Rowett Institute and Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Aberdeen, United Kingdom
| | - Weiping Han
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
| | - Lora K. Heisler
- The Rowett Institute and Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Aberdeen, United Kingdom
| | - Justin J. Rochford
- The Rowett Institute and Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Aberdeen, United Kingdom
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Yang G, Li C, Wang S, Liang X, Yang B, Zhang Y, Zhang X, Chang X, Meng X. Molecular characterization of the grass carp bscl2 gene and its expression response to lipid accumulation, nutritional status, insulin and glucagon. Comp Biochem Physiol B Biochem Mol Biol 2024; 270:110931. [PMID: 38070669 DOI: 10.1016/j.cbpb.2023.110931] [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: 07/12/2023] [Revised: 12/03/2023] [Accepted: 12/03/2023] [Indexed: 01/10/2024]
Abstract
Bscl2 plays a role in lipid metabolism of mammals, however its role in teleost fish remains unclear. Using the grass carp (Ctenopharyngodon idella) as a model, the bscl2 gene was isolated from the brain and characterized. Thereafter, the tissue distribution of the gene was examined, before expression was analyzed as a function of fasting, refeeding, oral glucose administration and overfeeding. In addition, bscl2 mRNA levels were evaluated in grass carp primary hepatocytes treated with glucagon, insulin, oleic acid, and glucose. Results showed that the cloned bscl2 gene was 1341 bp, encoding 446 amino acids, and was highly expressed in the brain, heart, and gonad. Following oral glucose administration, bscl2 expression increased. Expression of bscl2 decreased in fasted fish but increased following refeeding. Overfeeding, which resulted in elevated lipid accumulation, also stimulated bscl2 expression. In primary hepatocytes, bscl2 levels were increased by glucose, oleic acid, and insulin treatments, and reduced by glucagon treatment. These data suggest that bscl2 may play an important role in nutrient metabolism in teleost fish.
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Affiliation(s)
- Guokun Yang
- College of Fisheries, Henan Normal University, Xinxiang 453007, PR China; Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, Henan Normal University, Xinxiang 453007, PR China
| | - Chengquan Li
- College of Fisheries, Henan Normal University, Xinxiang 453007, PR China
| | - Sunan Wang
- College of Fisheries, Henan Normal University, Xinxiang 453007, PR China
| | - Xiaomin Liang
- College of Fisheries, Henan Normal University, Xinxiang 453007, PR China
| | - Boya Yang
- College of Fisheries, Henan Normal University, Xinxiang 453007, PR China
| | - Yanmin Zhang
- College of Fisheries, Henan Normal University, Xinxiang 453007, PR China; Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, Henan Normal University, Xinxiang 453007, PR China
| | - Xindang Zhang
- College of Fisheries, Henan Normal University, Xinxiang 453007, PR China; Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, Henan Normal University, Xinxiang 453007, PR China
| | - Xulu Chang
- College of Fisheries, Henan Normal University, Xinxiang 453007, PR China; Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, Henan Normal University, Xinxiang 453007, PR China
| | - Xiaolin Meng
- College of Fisheries, Henan Normal University, Xinxiang 453007, PR China; Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, Henan Normal University, Xinxiang 453007, PR China.
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9
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Deng Y, Zhu H, Wang Y, Dong Y, Du J, Yu Q, Li M. The Endoplasmic Reticulum-Plasma Membrane Tethering Protein Ice2 Controls Lipid Droplet Size via the Regulation of Phosphatidylcholine in Candida albicans. J Fungi (Basel) 2024; 10:87. [PMID: 38276033 PMCID: PMC10817647 DOI: 10.3390/jof10010087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/13/2024] [Accepted: 01/17/2024] [Indexed: 01/27/2024] Open
Abstract
Lipid droplets (LDs) are intracellular organelles that play important roles in cellular lipid metabolism; they change their sizes and numbers in response to both intracellular and extracellular signals. Changes in LD size reflect lipid synthesis and degradation and affect many cellular activities, including energy supply and membrane synthesis. Here, we focused on the function of the endoplasmic reticulum-plasma membrane tethering protein Ice2 in LD dynamics in the fungal pathogen Candida albicans (C. albicans). Nile red staining and size quantification showed that the LD size increased in the ice2Δ/Δ mutant, indicating the critical role of Ice2 in the regulation of LD dynamics. A lipid content analysis further demonstrated that the mutant had lower phosphatidylcholine levels. As revealed with GFP labeling and fluorescence microscopy, the methyltransferase Cho2, which is involved in phosphatidylcholine synthesis, had poorer localization in the plasma membrane in the mutant than in the wild-type strain. Interestingly, the addition of the phosphatidylcholine precursor choline led to the recovery of normal-sized LDs in the mutant. These results indicated that Ice2 regulates LD size by controlling intracellular phosphatidylcholine levels and that endoplasmic reticulum-plasma membrane tethering proteins play a role in lipid metabolism regulation in C. albicans. This study provides significant findings for further investigation of the lipid metabolism in fungi.
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Affiliation(s)
| | | | | | | | | | | | - Mingchun Li
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China; (Y.D.); (H.Z.); (Y.W.); (Y.D.); (J.D.)
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10
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Peng K, Chen X, Pei K, Wang X, Ma X, Liang C, Dong Q, Liu Z, Han M, Liu G, Yang H, Zheng M, Liu G, Gao M. Lipodystrophic gene Agpat2 deficiency aggravates hyperlipidemia and atherosclerosis in Ldlr -/- mice. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166850. [PMID: 37591406 DOI: 10.1016/j.bbadis.2023.166850] [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: 02/11/2023] [Revised: 08/11/2023] [Accepted: 08/12/2023] [Indexed: 08/19/2023]
Abstract
AIMS Dysfunction of adipose tissue increases the risk of cardiovascular disease. It was well established that obesity aggravates atherosclerosis, but the effect of adipose tissue loss on atherosclerosis has been less studied. AGPAT2 is the first causative gene of congenital generalized lipodystrophy (CGL), but the role of AGPAT2 on atherosclerosis has not been reported. Hypertriglyceridemia is one of the clinical manifestations of CGL patients, but it is usually absent in CGL mouse model on a normal diet. This study will investigate the effect of Agpat2 on hyperlipidemia and atherosclerosis. METHODS AND RESULTS In this study, Agpat2 knockout (Agpat2-/-) mice were generated using CRISPR/Cas system, which showed severe loss of adipose tissue and fatty liver, consistent with previous reports. Agpat2-/- mice were then crossed with hypercholesterolemic and atherosclerotic prone LDL receptor knockout (Ldlr-/-) mice to obtain double knockout mouse model (Agpat2-/-Ldlr-/-). Plasma lipid profile, insulin resistance, fatty liver, and atherosclerotic lesions were observed after 12 weeks of the atherogenic high-fat diet (HFD) feeding. We found that compared with Ldlr-/- mice, Agpat2-/-Ldlr-/- mice showed significantly higher plasma total cholesterol and triglycerides after HFD feeding. Agpat2-/-Ldlr-/- mice also developed hyperglycemia and hyperinsulinemia, with increased pancreatic islet area. The liver weight of Agpat2-/-Ldlr-/- mice was about 4 times higher than that of Ldlr-/- mice. The liver lipid deposition was severe and Sirius red staining showed liver fibrosis. In addition, in Agpat2-/-Ldlr-/- mice, the area of atherosclerotic lesions in aortic arch and aortic root was significantly increased. CONCLUSIONS Our results show that Agpat2 deficiency led to more severe hyperlipidemia, liver fibrosis and aggravation of atherosclerosis in Ldlr-/- mice. This study provided additional insights into the role of adipose tissue in hyperlipidemia and atherosclerosis.
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Affiliation(s)
- Kenan Peng
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China; Laboratory Department of Hebei General Hospital, Shijiazhuang, Hebei 050051, China
| | - Xin Chen
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China; Department of General Surgery, The First Hospital of Hebei Medical University, Shijiazhuang, Hebei 050031, China
| | - Kexin Pei
- Department of Cardiology, The First Hospital of Hebei Medical University, Shijiazhuang, Hebei 050031, China
| | - Xiaowei Wang
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Xindi Ma
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Chenxi Liang
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Qianqian Dong
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China; Department of Clinical Laboratory, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, China
| | - Ziwei Liu
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Mei Han
- Department of Biochemistry and Molecular Biology, Key Laboratory of Medical Biotechnology of Hebei Province, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - George Liu
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, the University of New South Wales, Sydney, NSW 2052, Australia
| | - Mingqi Zheng
- Department of Cardiology, The First Hospital of Hebei Medical University, Shijiazhuang, Hebei 050031, China.
| | - Gang Liu
- Department of Cardiology, The First Hospital of Hebei Medical University, Shijiazhuang, Hebei 050031, China.
| | - Mingming Gao
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China.
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11
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Cobelo-Gómez S, Sánchez-Iglesias S, Rábano A, Senra A, Aguiar P, Gómez-Lado N, García-Varela L, Burgueño-García I, Lampón-Fernández L, Fernández-Pombo A, Díaz-López EJ, Prado-Moraña T, San Millán B, Araújo-Vilar D. A murine model of BSCL2-associated Celia's encephalopathy. Neurobiol Dis 2023; 187:106300. [PMID: 37717662 DOI: 10.1016/j.nbd.2023.106300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 09/06/2023] [Accepted: 09/14/2023] [Indexed: 09/19/2023] Open
Abstract
Celia's encephalopathy or progressive encephalopathy with/without lipodystrophy is a neurodegenerative disease with a fatal prognosis in childhood. It is generally caused by the c.985C > T variant in the BSCL2 gene, leading to the skipping of exon 7 and resulting in an aberrant seipin protein (Celia-seipin). To precisely define the temporal evolution and the mechanisms involved in neurodegeneration, lipodystrophy and fatty liver in Celia's encephalopathy, our group has generated the first global knock-in murine model for the aberrant human transcript of BSCL2 (Bscl2Celia/Celia) using a strategy based on the Cre/loxP recombination system. In order to carry out a characterization at the neurological, adipose tissue and hepatic level, behavioral studies, brain PET, metabolic, histological and molecular studies were performed. Around 12% of homozygous and 5.4% of heterozygous knock-in mice showed severe neurological symptoms early in life, and their life expectancy was dramatically reduced. Severe generalized lipodystrophy and mild hepatic steatosis were present in these affected animals, while serum triglycerides and glucose metabolism were normal, with no insulin resistance. Furthermore, the study revealed a reduction in brain glucose uptake, along with patchy loss of Purkinje cells and the presence of intranuclear inclusions in cerebellar cortex cells. Homozygous, non-severely-affected knock-in mice showed a decrease in locomotor activity and greater anxiety compared with their wild type littermates. Bscl2Celia/Celia is the first murine model of Celia's encephalopathy which partially recapitulates the phenotype and severe neurodegenerative picture suffered by these patients. This model will provide a helpful tool to investigate both the progressive encephalopathy with/without lipodystrophy and congenital generalized lipodystrophy.
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Affiliation(s)
- Silvia Cobelo-Gómez
- UETeM-Molecular Pathology Group. Department of Psychiatry, Radiology, Public Health, Nursing and Medicine, IDIS-CIMUS, University of Santiago de Compostela, Spain
| | - Sofía Sánchez-Iglesias
- UETeM-Molecular Pathology Group. Department of Psychiatry, Radiology, Public Health, Nursing and Medicine, IDIS-CIMUS, University of Santiago de Compostela, Spain
| | - Alberto Rábano
- Alzheimer's Disease Research Unit, CIEN Foundation, Queen Sofia Foundation Alzheimer Center, Madrid, Spain
| | - Ana Senra
- Department of Physiology, CIMUS, University of Santiago de Compostela, Spain
| | - Pablo Aguiar
- Molecular Imaging and Medical Physics, University of Santiago de Compostela-IDIS, Spain; Nuclear Medicine and Molecular Imaging Group, IDIS, University Clinical Hospital of Santiago de Compostela, Spain
| | - Noemí Gómez-Lado
- Molecular Imaging and Medical Physics, University of Santiago de Compostela-IDIS, Spain; Nuclear Medicine and Molecular Imaging Group, IDIS, University Clinical Hospital of Santiago de Compostela, Spain
| | - Lara García-Varela
- Molecular Imaging and Medical Physics, University of Santiago de Compostela-IDIS, Spain; Nuclear Medicine and Molecular Imaging Group, IDIS, University Clinical Hospital of Santiago de Compostela, Spain
| | - Iván Burgueño-García
- Alzheimer's Disease Research Unit, CIEN Foundation, Queen Sofia Foundation Alzheimer Center, Madrid, Spain
| | - Laura Lampón-Fernández
- UETeM-Molecular Pathology Group. Department of Psychiatry, Radiology, Public Health, Nursing and Medicine, IDIS-CIMUS, University of Santiago de Compostela, Spain
| | - Antía Fernández-Pombo
- UETeM-Molecular Pathology Group. Department of Psychiatry, Radiology, Public Health, Nursing and Medicine, IDIS-CIMUS, University of Santiago de Compostela, Spain; Division of Endocrinology and Nutrition, University Clinical Hospital of Santiago de Compostela, Spain
| | - Everardo Josué Díaz-López
- UETeM-Molecular Pathology Group. Department of Psychiatry, Radiology, Public Health, Nursing and Medicine, IDIS-CIMUS, University of Santiago de Compostela, Spain; Division of Endocrinology and Nutrition, University Clinical Hospital of Santiago de Compostela, Spain
| | - Teresa Prado-Moraña
- UETeM-Molecular Pathology Group. Department of Psychiatry, Radiology, Public Health, Nursing and Medicine, IDIS-CIMUS, University of Santiago de Compostela, Spain; Division of Endocrinology and Nutrition, University Clinical Hospital of Santiago de Compostela, Spain
| | - Beatriz San Millán
- Grupo de Enfermedades Raras y Medicina Pediátrica, Instituto de Investigación Sanitaria Galicia Sur (IISGS), Vigo, Spain; Pathology Department, Alvaro Cunqueiro Hospital, Vigo, Spain
| | - David Araújo-Vilar
- UETeM-Molecular Pathology Group. Department of Psychiatry, Radiology, Public Health, Nursing and Medicine, IDIS-CIMUS, University of Santiago de Compostela, Spain; Division of Endocrinology and Nutrition, University Clinical Hospital of Santiago de Compostela, Spain.
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12
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Chitraju C, Fischer AW, Ambaw YA, Wang K, Yuan B, Hui S, Walther TC, Farese RV. Mice lacking triglyceride synthesis enzymes in adipose tissue are resistant to diet-induced obesity. eLife 2023; 12:RP88049. [PMID: 37782317 PMCID: PMC10545428 DOI: 10.7554/elife.88049] [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] [Indexed: 10/03/2023] Open
Abstract
Triglycerides (TGs) in adipocytes provide the major stores of metabolic energy in the body. Optimal amounts of TG stores are desirable as insufficient capacity to store TG, as in lipodystrophy, or exceeding the capacity for storage, as in obesity, results in metabolic disease. We hypothesized that mice lacking TG storage in adipocytes would result in excess TG storage in cell types other than adipocytes and severe lipotoxicity accompanied by metabolic disease. To test this hypothesis, we selectively deleted both TG synthesis enzymes, DGAT1 and DGAT2, in adipocytes (ADGAT DKO mice). As expected with depleted energy stores, ADGAT DKO mice did not tolerate fasting well and, with prolonged fasting, entered torpor. However, ADGAT DKO mice were unexpectedly otherwise metabolically healthy and did not accumulate TGs ectopically or develop associated metabolic perturbations, even when fed a high-fat diet. The favorable metabolic phenotype resulted from activation of energy expenditure, in part via BAT (brown adipose tissue) activation and beiging of white adipose tissue. Thus, the ADGAT DKO mice provide a fascinating new model to study the coupling of metabolic energy storage to energy expenditure.
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Affiliation(s)
- Chandramohan Chitraju
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public HealthBostonUnited States
- Department of Cell Biology, Harvard Medical SchoolBostonUnited States
| | - Alexander W Fischer
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public HealthBostonUnited States
- Department of Cell Biology, Harvard Medical SchoolBostonUnited States
| | - Yohannes A Ambaw
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public HealthBostonUnited States
- Department of Cell Biology, Harvard Medical SchoolBostonUnited States
- Cell Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer CenterNew YorkUnited States
| | - Kun Wang
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public HealthBostonUnited States
- Department of Cell Biology, Harvard Medical SchoolBostonUnited States
| | - Bo Yuan
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public HealthBostonUnited States
| | - Sheng Hui
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public HealthBostonUnited States
| | - Tobias C Walther
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public HealthBostonUnited States
- Department of Cell Biology, Harvard Medical SchoolBostonUnited States
- Cell Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer CenterNew YorkUnited States
- Broad Institute of Harvard and MITCambridgeUnited States
- Howard Hughes Medical InstituteBostonUnited States
| | - Robert V Farese
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public HealthBostonUnited States
- Department of Cell Biology, Harvard Medical SchoolBostonUnited States
- Cell Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer CenterNew YorkUnited States
- Broad Institute of Harvard and MITCambridgeUnited States
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13
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Yang J, Yang N, Zhao H, Qiao Y, Li Y, Wang C, Lim KL, Zhang C, Yang W, Lu L. Adipose transplantation improves olfactory function and neurogenesis via PKCα-involved lipid metabolism in Seipin Knockout mice. Stem Cell Res Ther 2023; 14:239. [PMID: 37674230 PMCID: PMC10483743 DOI: 10.1186/s13287-023-03463-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 08/22/2023] [Indexed: 09/08/2023] Open
Abstract
BACKGROUND Lipodystrophy-associated metabolic disorders caused by Seipin deficiency lead to not only severe lipodystrophy but also neurological disorders. However, the underlying mechanism of Seipin deficiency-induced neuropathy is not well elucidated, and the possible restorative strategy needs to be explored. METHODS In the present study, we used Seipin knockout (KO) mice, combined with transcriptome analysis, mass spectrometry imaging, neurobehavior test, and cellular and molecular assay to investigate the systemic lipid metabolic abnormalities in lipodystrophic mice model and their effects on adult neurogenesis in the subventricular zone (SVZ) and olfactory function. After subcutaneous adipose tissue (AT) transplantation, metabolic and neurological function was measured in Seipin KO mice to clarify whether restoring lipid metabolic homeostasis would improve neurobehavior. RESULTS It was found that Seipin KO mice presented the ectopic accumulation of lipids in the lateral ventricle, accompanied by decreased neurogenesis in adult SVZ, diminished new neuron formation in the olfactory bulb, and impaired olfactory-related memory. Transcriptome analysis showed that the differentially expressed genes (DEGs) in SVZ of adult Seipin KO mice were significantly enriched in lipid metabolism. Mass spectrometry imaging showed that the levels of glycerophospholipid and diglyceride (DG) were significantly increased. Furthermore, we found that AT transplantation rescued the abnormality of peripheral metabolism in Seipin KO mice and ameliorated the ectopic lipid accumulation, concomitant with restoration of the SVZ neurogenesis and olfactory function. Mechanistically, PKCα expression was up-regulated in SVZ tissues of Seipin KO mice, which may be a potential mediator between lipid dysregulation and neurological disorder. DG analogue (Dic8) can up-regulate PKCα and inhibit the proliferation and differentiation of neural stem cells (NSCs) in vitro, while PKCα inhibitor can block this effect. CONCLUSION This study demonstrates that Seipin deficiency can lead to systemic lipid disorder with concomitant SVZ neurogenesis and impaired olfactory memory. However, AT restores lipid homeostasis and neurogenesis. PKCα is a key mediator mediating Seipin KO-induced abnormal lipid metabolism and impaired neurogenesis in the SVZ, and inhibition of PKCα can restore the impaired neurogenesis. This work reveals the underlying mechanism of Seipin deficiency-induced neurological dysfunction and provides new ideas for the treatment of neurological dysfunction caused by metabolic disorders.
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Affiliation(s)
- Jing Yang
- Department of Anatomy, Shanxi Medical University, Taiyuan, 030001, People's Republic of China
| | - Na Yang
- Department of Anatomy, Shanxi Medical University, Taiyuan, 030001, People's Republic of China
| | - Huifang Zhao
- School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, People's Republic of China
| | - Yan Qiao
- Analytical Instrumentation Center and State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, People's Republic of China
| | - Yanqiu Li
- Analytical Instrumentation Center and State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, People's Republic of China
| | - Chunfang Wang
- Laboratory Animal Research Center of Shanxi Medical University, Shanxi Key Laboratory of Animal and Animal Model of Human Diseases, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Kah-Leong Lim
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Chengwu Zhang
- School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, People's Republic of China.
| | - Wulin Yang
- Anhui Province Key Laboratory of Medical Physics and Technology, Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, People's Republic of China.
- Cancer Hospital, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, People's Republic of China.
| | - Li Lu
- Department of Anatomy, Shanxi Medical University, Taiyuan, 030001, People's Republic of China.
- Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, People's Republic of China.
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14
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Zadoorian A, Du X, Yang H. Lipid droplet biogenesis and functions in health and disease. Nat Rev Endocrinol 2023:10.1038/s41574-023-00845-0. [PMID: 37221402 DOI: 10.1038/s41574-023-00845-0] [Citation(s) in RCA: 89] [Impact Index Per Article: 89.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/25/2023] [Indexed: 05/25/2023]
Abstract
Ubiquitous yet unique, lipid droplets are intracellular organelles that are increasingly being recognized for their versatility beyond energy storage. Advances uncovering the intricacies of their biogenesis and the diversity of their physiological and pathological roles have yielded new insights into lipid droplet biology. Despite these insights, the mechanisms governing the biogenesis and functions of lipid droplets remain incompletely understood. Moreover, the causal relationship between the biogenesis and function of lipid droplets and human diseases is poorly resolved. Here, we provide an update on the current understanding of the biogenesis and functions of lipid droplets in health and disease, highlighting a key role for lipid droplet biogenesis in alleviating cellular stresses. We also discuss therapeutic strategies of targeting lipid droplet biogenesis, growth or degradation that could be applied in the future to common diseases, such as cancer, hepatic steatosis and viral infection.
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Affiliation(s)
- Armella Zadoorian
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Ximing Du
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia.
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15
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Peloso A, Tihy M, Moeckli B, Rubbia-Brandt L, Toso C. Clearing Steatosis Prior to Liver Surgery for Colorectal Metastasis: A Narrative Review and Case Illustration. Nutrients 2022; 14:5340. [PMID: 36558499 PMCID: PMC9785595 DOI: 10.3390/nu14245340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/26/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022] Open
Abstract
Over recent years, non-alcoholic fatty liver disease (NAFLD) has become the most common liver disorder in the developed world, accounting for 20% to 46% of liver abnormalities. Steatosis is the hallmark of NAFLD and is recognized as an important risk factor for complication and death after general surgery, even more so after liver resection. Similarly, liver steatosis also impacts the safety of live liver donation and transplantation. We aim to review surgical outcomes after liver resection for colorectal metastases in patients with steatosis and discuss the most common pre-operative strategies to reduce steatosis. Finally, as illustration, we report the favorable effect of a low-caloric, hyper-protein diet during a two-stage liver resection for colorectal metastases in a patient with severe steatosis.
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Affiliation(s)
- Andrea Peloso
- Division of Abdominal Surgery, Department of Surgery, Geneva University Hospitals, University of Geneva, 1205 Geneva, Switzerland
| | - Matthieu Tihy
- Department of Pathology and Immunology, University of Geneva, 1205 Geneva, Switzerland
- Division of Clinical Pathology, Geneva University Hospital, 1205 Geneva, Switzerland
| | - Beat Moeckli
- Division of Abdominal Surgery, Department of Surgery, Geneva University Hospitals, University of Geneva, 1205 Geneva, Switzerland
| | - Laura Rubbia-Brandt
- Department of Pathology and Immunology, University of Geneva, 1205 Geneva, Switzerland
- Division of Clinical Pathology, Geneva University Hospital, 1205 Geneva, Switzerland
| | - Christian Toso
- Division of Abdominal Surgery, Department of Surgery, Geneva University Hospitals, University of Geneva, 1205 Geneva, Switzerland
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16
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Sommer N, Roumane A, Han W, Delibegović M, Rochford JJ, Mcilroy GD. Gene therapy restores adipose tissue and metabolic health in a pre-clinical mouse model of lipodystrophy. Mol Ther Methods Clin Dev 2022; 27:206-216. [PMID: 36320417 PMCID: PMC9589143 DOI: 10.1016/j.omtm.2022.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 09/29/2022] [Indexed: 11/29/2022]
Abstract
Congenital generalized lipodystrophy type 2 is a serious multisystem disorder with limited treatment options. It is caused by mutations affecting the BSCL2 gene, which encodes the protein seipin. Patients with congenital generalized lipodystrophy type 2 lack both metabolic and mechanical adipose tissue and develop severe metabolic complications including hepatic steatosis, lipoatrophic diabetes, and cardiovascular disease. Gene therapies are becoming viable treatments, helping to alleviate inherited and acquired human disorders. We aimed to determine whether gene therapy could offer an effective form of medical intervention for lipodystrophy. We examined whether systemic adeno-associated virus delivery of human BSCL2 could reverse metabolic disease in seipin knockout mice, where white adipose tissue is absent. We reveal that adeno-associated virus gene therapy targets adipose progenitor cells in vivo and substantially restores white adipose tissue development in adult seipin knockout mice. This resulted in both rapid and prolonged beneficial effects to metabolic health in this pre-clinical mouse model of congenital generalized lipodystrophy type 2. Hyperglycemia was normalized within 2 weeks post-treatment together with normalization of severe insulin resistance. We propose that gene therapy offers great potential as a therapeutic strategy to correct multiple metabolic complications in patients with congenital lipodystrophy.
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Affiliation(s)
- Nadine Sommer
- The Rowett Institute, University of Aberdeen, Aberdeen AB25 2ZD, UK
- Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Ahlima Roumane
- The Rowett Institute, University of Aberdeen, Aberdeen AB25 2ZD, UK
- Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Aberdeen AB25 2ZD, UK
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, WA 6102, Australia
| | - Weiping Han
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A∗STAR), 138667 Singapore, Singapore
- Center for Neuro-Metabolism and Regeneration Research, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou 510700, China
- School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Mirela Delibegović
- Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Aberdeen AB25 2ZD, UK
- Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Justin J. Rochford
- The Rowett Institute, University of Aberdeen, Aberdeen AB25 2ZD, UK
- Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - George D. Mcilroy
- The Rowett Institute, University of Aberdeen, Aberdeen AB25 2ZD, UK
- Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Aberdeen AB25 2ZD, UK
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17
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Saito S, Ishikawa T, Ninagawa S, Okada T, Mori K. A motor neuron disease-associated mutation produces non-glycosylated Seipin that induces ER stress and apoptosis by inactivating SERCA2b. eLife 2022; 11:74805. [PMID: 36444643 PMCID: PMC9708084 DOI: 10.7554/elife.74805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 11/06/2022] [Indexed: 11/30/2022] Open
Abstract
A causal relationship between endoplasmic reticulum (ER) stress and the development of neurodegenerative diseases remains controversial. Here, we focused on Seipinopathy, a dominant motor neuron disease, based on the finding that its causal gene product, Seipin, is a protein that spans the ER membrane twice. Gain-of-function mutations of Seipin produce non-glycosylated Seipin (ngSeipin), which was previously shown to induce ER stress and apoptosis at both cell and mouse levels albeit with no clarified mechanism. We found that aggregation-prone ngSeipin dominantly inactivated SERCA2b, the major calcium pump in the ER, and decreased the calcium concentration in the ER, leading to ER stress and apoptosis in human colorectal carcinoma-derived cells (HCT116). This inactivation required oligomerization of ngSeipin and direct interaction of the C-terminus of ngSeipin with SERCA2b, and was observed in Seipin-deficient neuroblastoma (SH-SY5Y) cells expressing ngSeipin at an endogenous protein level. Our results thus provide a new direction to the controversy noted above.
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Affiliation(s)
- Shunsuke Saito
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Tokiro Ishikawa
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Satoshi Ninagawa
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Tetsuya Okada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Kazutoshi Mori
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
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18
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Lukmantara I, Chen F, Mak HY, Zadoorian A, Du X, Xiao FN, Norris DM, Pandzic E, Whan R, Zhong Q, Yang H. PI(3)P and DFCP1 regulate the biogenesis of lipid droplets. Mol Biol Cell 2022; 33:ar131. [PMID: 36129766 PMCID: PMC9727793 DOI: 10.1091/mbc.e22-07-0279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The biogenesis of lipid droplets (LDs), key organelles for cellular lipid storage and homeostasis, remains poorly understood. Seipin is essential to normal LD biogenesis but exactly how it regulates LD initiation remains to be elucidated. Our previous results suggested that seipin may bind anionic phospholipids such as PI(3)P. Here, we investigate whether PI(3)P is functionally linked to seipin and whether PI(3)P can also impact LD biogenesis. In seipin-deficient cells, there were enlarged PI(3)P puncta where its effector, DFCP1, also appeared to congregate. Reducing cellular PI(3)P partially rescued the defective LD initiation caused by seipin deficiency. Increasing PI(3)P impeded the lipidation of nascent LDs. We further demonstrated that DFCP1 localized to LDs and facilitated the efficient lipidation of nascent LDs. However, the normal function and localization of DFCP1 were disrupted when cellular PI(3)P homeostasis was perturbed. Our results thus identify PI(3)P as a novel regulator of LD initiation and suggest that PI(3)P may impact the biogenesis of LDs through DFCP1.
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Affiliation(s)
- Ivan Lukmantara
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Fang Chen
- Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200240, China
| | - Hoi Yin Mak
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Armella Zadoorian
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Ximing Du
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Fanqian Nicole Xiao
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Dougall MacMurray Norris
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Elvis Pandzic
- Katharina Gaus Light Microscopy Facility, Mark Wainwright Analytical Center, University of New South Wales, Sydney, NSW 2052, Australia
| | - Renee Whan
- Katharina Gaus Light Microscopy Facility, Mark Wainwright Analytical Center, University of New South Wales, Sydney, NSW 2052, Australia
| | - Qing Zhong
- Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200240, China
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia,*Address correspondence to: Hongyuan Yang ()
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19
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Li Y, Yang X, Peng L, Xia Q, Zhang Y, Huang W, Liu T, Jia D. Role of Seipin in Human Diseases and Experimental Animal Models. Biomolecules 2022; 12:biom12060840. [PMID: 35740965 PMCID: PMC9221541 DOI: 10.3390/biom12060840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/13/2022] [Accepted: 06/14/2022] [Indexed: 02/05/2023] Open
Abstract
Seipin, a protein encoded by the Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2) gene, is famous for its key role in the biogenesis of lipid droplets and type 2 congenital generalised lipodystrophy (CGL2). BSCL2 gene mutations result in genetic diseases including CGL2, progressive encephalopathy with or without lipodystrophy (also called Celia’s encephalopathy), and BSCL2-associated motor neuron diseases. Abnormal expression of seipin has also been found in hepatic steatosis, neurodegenerative diseases, glioblastoma stroke, cardiac hypertrophy, and other diseases. In the current study, we comprehensively summarise phenotypes, underlying mechanisms, and treatment of human diseases caused by BSCL2 gene mutations, paralleled by animal studies including systemic or specific Bscl2 gene knockout, or Bscl2 gene overexpression. In various animal models representing diseases that are not related to Bscl2 mutations, differential expression patterns and functional roles of seipin are also described. Furthermore, we highlight the potential therapeutic approaches by targeting seipin or its upstream and downstream signalling pathways. Taken together, restoring adipose tissue function and targeting seipin-related pathways are effective strategies for CGL2 treatment. Meanwhile, seipin-related pathways are also considered to have potential therapeutic value in diseases that are not caused by BSCL2 gene mutations.
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Affiliation(s)
- Yuying Li
- West China Pancreatitis Centre, Centre for Integrated Traditional Chinese Medicine and Western Medicine, West China-Liverpool Biomedical Research Centre, West China Hospital, Sichuan University, Chengdu 610041, China; (Y.L.); (X.Y.); (Q.X.)
| | - Xinmin Yang
- West China Pancreatitis Centre, Centre for Integrated Traditional Chinese Medicine and Western Medicine, West China-Liverpool Biomedical Research Centre, West China Hospital, Sichuan University, Chengdu 610041, China; (Y.L.); (X.Y.); (Q.X.)
| | - Linrui Peng
- Department of Endocrinology and Metabolism, West China Hospital of Sichuan University, Chengdu 610041, China; (L.P.); (Y.Z.)
| | - Qing Xia
- West China Pancreatitis Centre, Centre for Integrated Traditional Chinese Medicine and Western Medicine, West China-Liverpool Biomedical Research Centre, West China Hospital, Sichuan University, Chengdu 610041, China; (Y.L.); (X.Y.); (Q.X.)
| | - Yuwei Zhang
- Department of Endocrinology and Metabolism, West China Hospital of Sichuan University, Chengdu 610041, China; (L.P.); (Y.Z.)
| | - Wei Huang
- West China Pancreatitis Centre, Centre for Integrated Traditional Chinese Medicine and Western Medicine, West China-Liverpool Biomedical Research Centre, West China Hospital, Sichuan University, Chengdu 610041, China; (Y.L.); (X.Y.); (Q.X.)
- Institutes for Systems Genetics & Immunology and Inflammation, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu 610041, China
- Correspondence: (W.H.); (T.L.)
| | - Tingting Liu
- West China Pancreatitis Centre, Centre for Integrated Traditional Chinese Medicine and Western Medicine, West China-Liverpool Biomedical Research Centre, West China Hospital, Sichuan University, Chengdu 610041, China; (Y.L.); (X.Y.); (Q.X.)
- Correspondence: (W.H.); (T.L.)
| | - Da Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu 610041, China;
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20
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Zhou H, Li J, Su H, Li J, Lydic TA, Young ME, Chen W. BSCL2/Seipin deficiency in hearts causes cardiac energy deficit and dysfunction via inducing excessive lipid catabolism. Clin Transl Med 2022; 12:e736. [PMID: 35384404 PMCID: PMC8982503 DOI: 10.1002/ctm2.736] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 01/26/2022] [Accepted: 01/29/2022] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Heart failure (HF) is one of the leading causes of death worldwide and is associated with cardiac metabolic perturbations. Human Type 2 Berardinelli-Seip Congenital Lipodystrophy (BSCL2) disease is caused by mutations in the BSCL2 gene. Global lipodystrophic Bscl2-/- mice exhibit hypertrophic cardiomyopathy with reduced cardiac steatosis. Whether BSCL2 plays a direct role in regulating cardiac substrate metabolism and/or contractile function remains unknown. METHODS We generated mice with cardiomyocyte-specific deletion of Bscl2 (Bscl2cKO ) and studied their cardiac substrate utilisation, bioenergetics, lipidomics and contractile function under baseline or after either a treatment regimen using fatty acid oxidation (FAO) inhibitor trimetazidine (TMZ) or a prevention regimen with high-fat diet (HFD) feeding. Mice with partial ATGL deletion and cardiac-specific deletion of Bscl2 were also generated followed by cardiac phenotyping. RESULTS Different from hypertrophic cardiomyopathy in Bscl2-/- mice, mice with cardiac-specific deletion of Bscl2 developed systolic dysfunction with dilation. Myocardial BSCL2 deletion led to elevated ATGL expression and FAO along with reduced cardiac lipid contents. Cardiac dysfunction in Bscl2cKO mice was independent of mitochondrial dysfunction and oxidative stress, but associated with decreased metabolic reserve and ATP levels. Importantly, cardiac dysfunction in Bscl2cKO mice could be partially reversed by FAO inhibitor TMZ, or prevented by genetic abolishment of one ATGL allele or HFD feeding. Lipidomic analysis further identified markedly reduced glycerolipids, glycerophospholipids, NEFA and acylcarnitines in Bscl2cKO hearts, which were partially normalised by TMZ or HFD. CONCLUSIONS We identified a new form of cardiac dysfunction with excessive lipid utilisation which ultimately causes cardiac substrate depletion and bioenergetics failure. Our findings also uncover a crucial role of BSCL2 in controlling cardiac lipid catabolism and contractile function and provide novel insights into metabolically treating energy-starved HF using FAO inhibitor or HFD.
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Affiliation(s)
- Hongyi Zhou
- Department of PhysiologyMedical College of Georgia at Augusta UniversityAugustaGeorgiaUSA
| | - Jie Li
- Vascular Biology CenterMedical College of Georgia at Augusta UniversityAugustaGeorgiaUSA
| | - Huabo Su
- Vascular Biology CenterMedical College of Georgia at Augusta UniversityAugustaGeorgiaUSA
| | - Ji Li
- Department of SurgeryMorsani College of MedicineUniversity of South FloridaTampaFloridaUSA
| | - Todd A. Lydic
- Department of PhysiologyMichigan State UniversityEast LansingMichiganUSA
| | - Martin E Young
- Department of MedicineUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Weiqin Chen
- Department of PhysiologyMedical College of Georgia at Augusta UniversityAugustaGeorgiaUSA
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21
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Rochford JJ. When Adipose Tissue Lets You Down: Understanding the Functions of Genes Disrupted in Lipodystrophy. Diabetes 2022; 71:589-598. [PMID: 35316838 DOI: 10.2337/dbi21-0006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 12/22/2021] [Indexed: 11/13/2022]
Abstract
Lipodystrophy syndromes are conditions in which the adipose tissue mass of an individual is altered inappropriately. The change in adipose mass can range from a relatively modest and subtle redistribution in some individuals with partial lipodystrophy to a near-complete absence of adipose tissue in the most severe forms of generalized lipodystrophy. The common feature is a disconnection between the need of the individual for a safe, healthy lipid storage capacity and the available adipose mass to perform this critical role. The inability to partition lipids for storage in appropriately functioning adipocytes leads to lipid accumulation in other tissues, which typically results in conditions such as diabetes, dyslipidemia, fatty liver, and cardiovascular disease. Several genes have been identified whose disruption leads to inherited forms of lipodystrophy. There is a link between some of these genes and adipose dysfunction, so the molecular basis of disease pathophysiology appears clear. However, for other lipodystrophy genes, it is not evident why their disruption should affect adipose development or function or, in the case of partial lipodystrophy, why only some adipose depots should be affected. Elucidating the molecular functions of these genes and their cellular and physiological effects has the capacity to uncover fundamental new insights regarding the development and functions of adipose tissue. This information is also likely to inform better management of lipodystrophy and improved treatments for patients. In addition, the findings will often be relevant to other conditions featuring adipose tissue dysfunction, including the more common metabolic disease associated with obesity.
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22
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Iqbal J, Jiang HL, Wu HX, Li L, Zhou YH, Hu N, Xiao F, Wang T, Xu SN, Zhou HD. Hereditary severe insulin resistance syndrome: Pathogenesis, pathophysiology, and clinical management. Genes Dis 2022. [PMID: 37492723 PMCID: PMC10363564 DOI: 10.1016/j.gendis.2022.03.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Severe insulin resistance has been linked to some of the most globally prevalent disorders, such as diabetes mellitus, nonalcoholic fatty liver disease, polycystic ovarian syndrome, and hypertension. Hereditary severe insulin resistance syndrome (H-SIRS) is a rare disorder classified into four principal categories: primary insulin receptor defects, lipodystrophies, complex syndromes, and obesity-related H-SIRS. Genes such as INSR, AKT2, TBC1D4, AGPAT2, BSCL2, CAV1, PTRF, LMNA, PPARG, PLIN1, CIDEC, LIPE, PCYT1A, MC4R, LEP, POMC, SH2B1, RECQL2, RECQL3, ALMS1, PCNT, ZMPSTE24, PIK3R1, and POLD1 have been linked to H-SIRS. Its clinical features include insulin resistance, hyperglycemia, hyperandrogenism, severe dyslipidemia, fatty liver, abnormal topography of adipose tissue, and low serum leptin and adiponectin levels. Diagnosis of H-SIRS is based on the presence of typical clinical features associated with the various H-SIRS forms and the identification of mutations in H-SIRS-linked genes by genetic testing. Diet therapy, insulin sensitization, exogenous insulin therapy, and leptin replacement therapy have widely been adopted to manage H-SIRS. The rarity of H-SIRS, its highly variable clinical presentation, refusal to be tested for genetic mutations by patients' family members who are not severely sick, unavailability of genetic testing, and testing expenses contribute to the delayed or underdiagnoses of H-SIRS. Early diagnosis facilitates early management of the condition, which results in improved glycemic control and delayed onset of diabetes and other complications related to severe insulin resistance. The use of updated genetic sequencing technologies is recommended, and long-term studies are required for genotype-phenotype differentiation and formulation of diagnostic and treatment protocols.
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23
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Yang Y, Ma L, Sun J, Gong X, Cai C, Hong W. The neonatal onset diabetes mellitus of Chinese neonate with congenital generalized lipodystrophy 2: a case report. BMC Endocr Disord 2022; 22:83. [PMID: 35351089 PMCID: PMC8961907 DOI: 10.1186/s12902-022-00992-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/17/2022] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Congenital generalized lipodystrophy (CGL) is a clinically heterogeneous disorder characterized by near total absence of adipose tissue along with metabolic complications. Diabetes mellitus developed from CGL usually present between ages 15 and 20 years, and there are few reports in neonate. CASE PRESENTATION In this report, we described a rare clinical presentation of CGL in a 12-day-old Chinese female neonates with hyperglycemia, hyperlipidemia, and subsequently appeared diabetes, hepatomegaly and fatty liver. The two clinical-exome sequencing identified heterozygous null mutations (c.793C > T and c.565G > T) in BSCL2 gene which was inherited from father and mother respectively. To date, it was the firstly reported CGL patient with neonatal onset diabetes. The neonate was treated with antibiotic, insulin and deeply hydrolyzed formula milk to significantly decrease FBG and serum trigylcerides levels. CONCLUSIONS: Our case report analyzes the causes of early onset diabetes may relate with the locus of BSCL2 gene mutations and infection induction. It also suggests the importance of early identification, genetic analysis, and symptomatic treatment in the CGL, which are essential for improving the prognosis of children.
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Affiliation(s)
- Yuan Yang
- Department of Neonatology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 200062, China
| | - Li Ma
- Department of Neonatology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 200062, China
| | - Jingjing Sun
- Department of Neonatology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 200062, China
| | - Xiaohui Gong
- Department of Neonatology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 200062, China
| | - Cheng Cai
- Department of Neonatology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 200062, China
| | - Wenchao Hong
- Department of Neonatology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 200062, China.
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24
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Magré J, Prieur X. Seipin Deficiency as a Model of Severe Adipocyte Dysfunction: Lessons from Rodent Models and Teaching for Human Disease. Int J Mol Sci 2022; 23:740. [PMID: 35054926 PMCID: PMC8775404 DOI: 10.3390/ijms23020740] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 02/05/2023] Open
Abstract
Obesity prevalence is increasing worldwide, leading to cardiometabolic morbidities. Adipocyte dysfunction, impairing white adipose tissue (WAT) expandability and metabolic flexibility, is central in the development of obesity-related metabolic complications. Rare syndromes of lipodystrophy characterized by an extreme paucity of functional adipose tissue should be considered as primary adipocyte dysfunction diseases. Berardinelli-Seip congenital lipodystrophy (BSCL) is the most severe form with a near absence of WAT associated with cardiometabolic complications such as insulin resistance, liver steatosis, dyslipidemia, and cardiomyopathy. Twenty years ago, mutations in the BSCL2 gene have been identified as the cause of BSCL in human. BSCL2 encodes seipin, an endoplasmic reticulum (ER) anchored protein whose function was unknown back then. Studies of seipin knockout mice or rats demonstrated how seipin deficiency leads to severe lipodystrophy and to cardiometabolic complications. At the cellular levels, seipin is organized in multimers that are particularly enriched at ER/lipid droplet and ER/mitochondria contact sites. Seipin deficiency impairs both adipocyte differentiation and mature adipocyte maintenance. Experiments using adipose tissue transplantation in seipin knockout mice and tissue-specific deletion of seipin have provided a large body of evidence that liver steatosis, cardiomyopathy, and renal injury, classical diabetic complications, are all consequences of lipodystrophy. Rare adipocyte dysfunctions such as in BSCL are the key paradigm to unravel the pathways that control adipocyte homeostasis. The knowledge gathered through the study of these pathologies may bring new strategies to maintain and improve adipose tissue expandability.
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Affiliation(s)
| | - Xavier Prieur
- Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, L’institut du Thorax, Université de Nantes, F-44000 Nantes, France;
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25
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Seipin localizes at endoplasmic-reticulum-mitochondria contact sites to control mitochondrial calcium import and metabolism in adipocytes. Cell Rep 2022; 38:110213. [PMID: 35021082 DOI: 10.1016/j.celrep.2021.110213] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 10/11/2021] [Accepted: 12/14/2021] [Indexed: 12/31/2022] Open
Abstract
Deficiency of the endoplasmic reticulum (ER) protein seipin results in generalized lipodystrophy by incompletely understood mechanisms. Here, we report mitochondrial abnormalities in seipin-deficient patient cells. A subset of seipin is enriched at ER-mitochondria contact sites (MAMs) in human and mouse cells and localizes in the vicinity of calcium regulators SERCA2, IP3R, and VDAC. Seipin association with MAM calcium regulators is stimulated by fasting-like stimuli, while seipin association with lipid droplets is promoted by lipid loading. Acute seipin removal does not alter ER calcium stores but leads to defective mitochondrial calcium import accompanied by a widespread reduction in Krebs cycle metabolites and ATP levels. In mice, inducible seipin deletion leads to mitochondrial dysfunctions preceding the development of metabolic complications. Together, these data suggest that seipin controls mitochondrial energy metabolism by regulating mitochondrial calcium influx at MAMs. In seipin-deficient adipose tissue, reduced ATP production compromises adipocyte properties, contributing to lipodystrophy pathogenesis.
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26
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Le Lay S, Magré J, Prieur X. Not Enough Fat: Mouse Models of Inherited Lipodystrophy. Front Endocrinol (Lausanne) 2022; 13:785819. [PMID: 35250856 PMCID: PMC8895270 DOI: 10.3389/fendo.2022.785819] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 01/17/2022] [Indexed: 12/19/2022] Open
Abstract
Lipodystrophies belong to the heterogenous group of syndromes in which the primary defect is a generalized or partial absence of adipose tissue, which may be congenital or acquired in origin. Lipodystrophy should be considered in patients manifesting the combination of insulin resistance (with or without overt diabetes), dyslipidemia and fatty liver. Lipodystrophies are classified according to the etiology of the disease (genetic or acquired) and to the anatomical distribution of adipose tissue (generalized or partial). The mechanism of adipose tissue loss is specific to each syndrome, depending on the biological function of the mutated gene. Mice models, together with cellular studies have permitted clarification of the mechanisms by which human mutations deeply compromise adipocyte homeostasis. In addition, rodent models have proven to be crucial in deciphering the cardiometabolic consequences of the lack of adipose tissue such as NAFLD, muscle insulin resistance and cardiomyopathy. More precisely, tissue-specific transgenic and knockout mice have brought new tools to distinguish phenotypic traits that are the consequences of lipodystrophy from those that are cell-autonomous. In this review, we discuss the mice models of lipodystrophy including those of inherited human syndromes of generalized and partial lipodystrophy. We present how these models have demonstrated the central role of white adipose tissue in energetic homeostasis in general, including insulin sensitivity and lipid handling in particular. We underscore the differences reported with the human phenotype and discuss the limit of rodent models in recapitulating adipose tissue primary default. Finally, we present how these mice models have highlighted the function of the causative-genes and brought new insights into the pathophysiology of the cardiometabolic complications associated with lipodystrophy.
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Affiliation(s)
- Soazig Le Lay
- Nantes Université, CNRS, INSERM, l’institut du thorax, Nantes, France
- Univ Angers, SFR ICAT, Angers, France
| | - Jocelyne Magré
- Nantes Université, CNRS, INSERM, l’institut du thorax, Nantes, France
| | - Xavier Prieur
- Nantes Université, CNRS, INSERM, l’institut du thorax, Nantes, France
- *Correspondence: Xavier Prieur,
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27
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Stranahan AM. Visceral adiposity, inflammation, and hippocampal function in obesity. Neuropharmacology 2021; 205:108920. [PMID: 34902347 DOI: 10.1016/j.neuropharm.2021.108920] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 11/09/2021] [Accepted: 12/08/2021] [Indexed: 02/06/2023]
Abstract
The 'apple-shaped' anatomical pattern that accompanies visceral adiposity increases risk for multiple chronic diseases, including conditions that impact the brain, such as diabetes and hypertension. However, distinguishing between the consequences of visceral obesity, as opposed to visceral adiposity-associated metabolic and cardiovascular pathologies, presents certain challenges. This review summarizes current literature on relationships between adipose tissue distribution and cognition in preclinical models and highlights unanswered questions surrounding the potential role of tissue- and cell type-specific insulin resistance in these effects. While gaps in knowledge persist related to insulin insensitivity and cognitive impairment in obesity, several recent studies suggest that cells of the neurovascular unit contribute to hippocampal synaptic dysfunction, and this review interprets those findings in the context of progressive metabolic dysfunction in the CNS. Signalling between cerebrovascular endothelial cells, astrocytes, microglia, and neurons has been linked with memory deficits in visceral obesity, and this article describes the cellular changes in each of these populations with respect to their role in amplification or diminution of peripheral signals. The picture emerging from these studies, while incomplete, implicates pro-inflammatory cytokines, insulin resistance, and hyperglycemia in various stages of obesity-induced hippocampal dysfunction. As in the parable of the five blind wanderers holding different parts of an elephant, considerable work remains in order to assemble a model for the underlying mechanisms linking visceral adiposity with age-related cognitive decline.
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Affiliation(s)
- Alexis M Stranahan
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, 1462 Laney Walker Blvd, Augusta, GA, 30912, USA.
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28
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Ramos-Lopes J, Ribeiro J, Laço M, Alves C, Matos A, Costa C. A De Novo BSCL2 Gene S90L Mutation in a Progressive Tetraparesis with Urinary Dysfunction and Corpus Callosum Involvement. J Pediatr Genet 2021; 10:253-258. [PMID: 34504732 PMCID: PMC8416207 DOI: 10.1055/s-0040-1713768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 05/20/2020] [Indexed: 10/23/2022]
Abstract
A Silver syndrome is a rare autosomal dominant spastic paraparesis in which spasticity of the lower limbs is accompanied by amyotrophy of the small hand muscles. The causative gene is the Berardinelli-Seip congenital lipodystrophy 2 ( BSCL2) , which is related to a spectrum of neurological phenotypes. In the current study, we presented a 14-year-old male with a slowly progressive spastic paraparesis with urinary incontinence that later on exhibited atrophy and weakness in the thenar and dorsal interosseous muscles. Magnetic resonance imaging (MRI) revealed discrete atrophy of the corpus callosum isthmus and an extended next-generation sequencing panel identified a de novo heterozygous mutation in BSCL2 gene, c.269C > T p.(S90L). Various clinical expression and incomplete penetrance of BSCL2 gene mutations complicate the establishment of a genetic etiology for these cases. Therefore, Silver syndrome should be included in the differential diagnosis if the initial presentation is a spastic paraparesis by urinary involvement with childhood-onset, even with MRI atypical findings. This report described the first Iberian Silver syndrome case carrying a de novo c.269C > T p. (S90L) BSCL2 gene mutation.
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Affiliation(s)
- Joana Ramos-Lopes
- Department of Neurology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Joana Ribeiro
- Child Development Centre, Pediatric Hospital, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Mário Laço
- Medical Genetics Unit, Pediatric Hospital, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Cristina Alves
- Orthopedics Department, Pediatric Hospital, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Anabela Matos
- Department of Neurology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Cármen Costa
- Child Development Centre, Pediatric Hospital, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
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29
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Wang M, Xing J, Liu M, Gao M, Liu Y, Li X, Hu L, Zhao X, Liao J, Liu G, Dong J. Deletion of Seipin Attenuates Vascular Function and the Anticontractile Effect of Perivascular Adipose Tissue. Front Cardiovasc Med 2021; 8:706924. [PMID: 34409079 PMCID: PMC8365033 DOI: 10.3389/fcvm.2021.706924] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 07/13/2021] [Indexed: 11/13/2022] Open
Abstract
Seipin locates in endoplasmic reticulum (ER) and regulates adipogenesis and lipid droplet formation. Deletion of Seipin has been well-demonstrated to cause severe general lipodystrophy, however, its role in maintaining perivascular adipose tissue (PVAT) and vascular homeostasis has not been directly assessed. In the present study, we investigated the role of Seipin in mediating the anticontractile effect of PVAT and vascular function. Seipin expression in PVAT and associated vessels were detected by qPCR and western-blot. Seipin is highly expressed in PVAT, but hardly in vessels. Structural and functional alterations of PVAT and associated vessels were compared between Seipin−/− mice and WT mice. In Seipin−/− mice, aortic and mesenteric PVAT were significantly reduced in mass and adipose-derived relaxing factors (ADRFs) secretion, but increased in macrophage infiltration and ER stress, as compared with those in WT mice. Aortic and mesenteric artery rings from WT and Seipin−/− mice were mounted on a wire myograph. Vasoconstriction and vasodilation were studied in vessels with and without PVAT. WT PVAT augmented relaxation but not Seipin−/− PVAT, which suggest impaired anticontractile function in PVAT of Seipin−/− mice. Thoracic aorta and mesenteric artery from Seipin−/− mice had impaired contractility in response to phenylephrine (PHE) and relaxation to acetylcholine (Ach). In conclusion, Seipin deficiency caused abnormalities in PVAT morphology and vascular functions. Our data demonstrated for the first time that Seipin plays a critical role in maintaining PVAT function and vascular homeostasis.
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Affiliation(s)
- Mengyu Wang
- Department of Cardiology, Henan Key Laboratory of Hereditary Cardiovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Junhui Xing
- Department of Cardiology, Henan Key Laboratory of Hereditary Cardiovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Mengduan Liu
- Department of Cardiology, Henan Key Laboratory of Hereditary Cardiovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Mingming Gao
- Laboratory of Lipid Metabolism, Hebei Medical University, Shijiazhuang, China
| | - Yangyang Liu
- Department of Cardiology, Henan Key Laboratory of Hereditary Cardiovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xiaowei Li
- Department of Cardiology, Henan Key Laboratory of Hereditary Cardiovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Liang Hu
- Department of Cardiology, Henan Key Laboratory of Hereditary Cardiovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xiaoyan Zhao
- Department of Cardiology, Henan Key Laboratory of Hereditary Cardiovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Jiawei Liao
- Department of Cardiology, Institute of Cardiovascular Diseases, First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - George Liu
- Key Laboratory of Molecular Cardiovascular Sciences, Peking University Health Science Center, School of Basic Medical Sciences, Institute of Cardiovascular Sciences, Ministry of Education, Beijing, China
| | - Jianzeng Dong
- Department of Cardiology, Henan Key Laboratory of Hereditary Cardiovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Department of Cardiology, National Clinical Research Centre for Cardiovascular Diseases, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
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Rao MJ, Goodman JM. Seipin: harvesting fat and keeping adipocytes healthy. Trends Cell Biol 2021; 31:912-923. [PMID: 34215489 DOI: 10.1016/j.tcb.2021.06.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/29/2021] [Accepted: 06/03/2021] [Indexed: 01/17/2023]
Abstract
Seipin is a key protein in the assembly of cytoplasmic lipid droplets (cLDs) and their maintenance at endoplasmic reticulum (ER)-LD junctions; the absence of seipin results in generalized lipodystrophy. How seipin mediates LD dynamics and prevents lipodystrophy are not well understood. New evidence suggests that seipin attracts triglyceride monomers from the ER to sites of droplet formation. By contrast, seipin may not be directly involved in the assembly of nuclear LDs and may actually suppress their formation at a distance. Seipin promotes adipogenesis, but lipodystrophy may also involve postadipogenic effects. We hypothesize that among these are a cycle of runaway lipolysis and lipotoxicity caused by aberrant LDs, resulting in a depletion of fat stores and a failure of adipose and other cells to thrive.
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Affiliation(s)
- Monala Jayaprakash Rao
- Department of Pharmacology, University of Texas Southwestern Medical School, Dallas, TX 75390-9041, USA
| | - Joel M Goodman
- Department of Pharmacology, University of Texas Southwestern Medical School, Dallas, TX 75390-9041, USA.
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31
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Gao M, Liu L, Wang X, Mak HY, Liu G, Yang H. GPAT3 deficiency alleviates insulin resistance and hepatic steatosis in a mouse model of severe congenital generalized lipodystrophy. Hum Mol Genet 2021; 29:432-443. [PMID: 31873720 DOI: 10.1093/hmg/ddz300] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/12/2019] [Accepted: 12/05/2019] [Indexed: 12/17/2022] Open
Abstract
Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2) is the most severe form of human lipodystrophy and is caused by loss-of-function mutations in the BSCL2/seipin gene. Exactly how seipin may regulate adipogenesis remains unclear. A recent study in vitro suggested that seipin may function to inhibit the activity of glycerol-3-phosphate acyltransferases (GPATs), and increased GPAT activity may be responsible for the defective adipogenesis under seipin deficiency. Here we generated Seipin-/-Gpat3-/- mice, which had mild but significant recovery of white adipose tissue mass over Seipin-/- mice. The mass of brown adipose tissue (BAT) of the Seipin-/-Gpat3-/- mice was almost completely restored to normal level. Importantly, the Seipin-/-Gpat3-/- mice showed significant improvement in liver steatosis and insulin sensitivity over Seipin-/- mice, which is attributable to the increased BAT mass and to the enhanced browning of the subcutaneous fat of the Seipin-/-Gpat3-/- mice. Together, our results establish a functional link between seipin and GPAT3 in vivo and suggest that GPAT inhibitors may have beneficial effects on BSCL2 patients.
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Affiliation(s)
- Mingming Gao
- Laboratory of Lipid Metabolism, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Lin Liu
- Laboratory of Lipid Metabolism, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Xiaowei Wang
- Laboratory of Lipid Metabolism, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Hoi Yin Mak
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
| | - George Liu
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing 100191, China
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
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Chartschenko E, Hugenroth M, Akhtar I, Droste A, Kolkhof P, Bohnert M, Beller M. CG32803 is the fly homolog of LDAF1 and influences lipid storage in vivo. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2021; 133:103512. [PMID: 33307187 DOI: 10.1016/j.ibmb.2020.103512] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 11/05/2020] [Accepted: 11/29/2020] [Indexed: 06/12/2023]
Abstract
The Seipin protein is a conserved key component in the biogenesis of lipid droplets (LDs). Recently, a cooperation between human Seipin and the Lipid droplet assembly factor 1 (LDAF1) was described. LDAF1 physically interacts with Seipin and the holocomplex safeguards regular LD biogenesis. The function of LDAF1 proteins outside mammals is less clear. In yeast, the lipid droplet organization (LDO) proteins, which also cooperate with Seipin, are the putative homologs of LDAF1. While certain functional aspects are shared between the LDO and mammalian LDAF1 proteins, the relationship between the proteins is under debate. Here, we identify the Drosophila melanogaster protein CG32803, which we re-named to dmLDAF1, as an insect member of this protein family. dmLDAF1 decorates LDs in cultured cells and in vivo and the protein is linked to the fly and mouse Seipin proteins. Altering the dmLDAF1 abundance affects LD size, number and overall lipid storage amounts. Our results suggest that the LDAF1 proteins thus fulfill an evolutionarily conserved function in the biogenesis and biology of LDs.
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Affiliation(s)
- Eugenia Chartschenko
- Institute for Mathematical Modeling of Biological Systems, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany; Systems Biology of Lipid Metabolism, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Marie Hugenroth
- Institute of Cell Dynamics and Imaging, University of Münster, Von-Esmarch-Str. 56, Münster, 48149, Germany; Cells in Motion Interfaculty Centre (CiM), University of Münster, Münster, 48149, Germany
| | - Irfan Akhtar
- Institute for Mathematical Modeling of Biological Systems, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany; Systems Biology of Lipid Metabolism, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Andrea Droste
- Institute for Mathematical Modeling of Biological Systems, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany; Systems Biology of Lipid Metabolism, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Petra Kolkhof
- Institute for Mathematical Modeling of Biological Systems, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany; Systems Biology of Lipid Metabolism, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Maria Bohnert
- Institute of Cell Dynamics and Imaging, University of Münster, Von-Esmarch-Str. 56, Münster, 48149, Germany; Cells in Motion Interfaculty Centre (CiM), University of Münster, Münster, 48149, Germany
| | - Mathias Beller
- Institute for Mathematical Modeling of Biological Systems, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany; Systems Biology of Lipid Metabolism, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany.
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Wu X, Liu X, Wang H, Zhou Z, Yang C, Li Z, Zhang Y, Shi X, Zhang L, Wang Y, Xian X, Liu G, Huang W. Seipin Deficiency Accelerates Heart Failure Due to Calcium Handling Abnormalities and Endoplasmic Reticulum Stress in Mice. Front Cardiovasc Med 2021; 8:644128. [PMID: 33778025 PMCID: PMC7990891 DOI: 10.3389/fcvm.2021.644128] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 02/15/2021] [Indexed: 12/19/2022] Open
Abstract
Seipin deficiency can induce hypertrophic cardiomyopathy and heart failure, which often leads to death in humans. To explore the effects and the possible mechanisms of Seipin deficiency in myocardial remodeling, Seipin knockout (SKO) mice underwent transverse aortic constriction (TAC) for 12 weeks. We found a more severe left ventricular hypertrophy and diastolic heart failure and increases in inflammatory cell infiltration, collagen deposition, and apoptotic bodies in the SKO group compared to those in the wild type (WT) group after TAC. Electron microscopy also showed a more extensive sarcoplasmic reticulum expansion, deformation of microtubules, and formation of mitochondrial lesions in the cardiomyocytes of SKO mice than in those of WT mice after TAC. Compared with the WT group, the SKO group showed increases in endoplasmic reticulum (ER) stress-, inflammation-, and fibrosis-related gene expression, while calcium ion-related factors, such as Serca2a and Ryr, were decreased in the SKO group after TAC. Increased levels of the ER stress-related protein GRP78 and decreased SERCA2a and P-RYR protein levels were detected in the SKO group compared with the WT group after TAC. Slowing of transient Ca2+ current decay and an increased SR Ca2+ content in myocytes were detected in the cardiomyocytes of SKO mice. Adipose tissue transplantation could not rescue the cardiac hypertrophy after TAC in SKO mice. In conclusion, we found that Seipin deficiency could promote cardiac hypertrophy and diastolic heart failure after TAC in mice. These changes may be related to the impairment of myocardial calcium handling, ER stress, inflammation, and apoptosis.
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Affiliation(s)
- Xiaoyue Wu
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Xuejing Liu
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Huan Wang
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Zihao Zhou
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Chengzhi Yang
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Zijian Li
- Institute of Vascular Medicine, Peking University Third Hospital, Beijing, China
| | - Youyi Zhang
- Institute of Vascular Medicine, Peking University Third Hospital, Beijing, China
| | - XiaoLu Shi
- Experimental Research Center, China Academy of Chinese Medical Science, Beijing, China
| | - Ling Zhang
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Yuhui Wang
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Xunde Xian
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - George Liu
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Wei Huang
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
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Bscl2 Deficiency Does Not Directly Impair the Innate Immune Response in a Murine Model of Generalized Lipodystrophy. J Clin Med 2021; 10:jcm10030441. [PMID: 33498782 PMCID: PMC7865406 DOI: 10.3390/jcm10030441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/13/2021] [Accepted: 01/15/2021] [Indexed: 11/28/2022] Open
Abstract
Congenital Generalized Lipodystrophy type 2 (CGL2) is the most severe form of lipodystrophy and is caused by mutations in the BSCL2 gene. Affected patients exhibit a near complete lack of adipose tissue and suffer severe metabolic disease. A recent study identified infection as a major cause of death in CGL2 patients, leading us to examine whether Bscl2 loss could directly affect the innate immune response. We generated a novel mouse model selectively lacking Bscl2 in the myeloid lineage (LysM-B2KO) and also examined the function of bone-marrow-derived macrophages (BMDM) isolated from global Bscl2 knockout (SKO) mice. LysM-B2KO mice failed to develop lipodystrophy and metabolic disease, providing a model to study the direct role of Bscl2 in myeloid lineage cells. Lipopolysaccharide-mediated stimulation of inflammatory cytokines was not impaired in LysM-B2KO mice or in BMDM isolated from either LysM-B2KO or SKO mice. Additionally, intracellular fate and clearance of bacteria in SKO BMDM challenged with Staphylococcus aureus was indistinguishable from that in BMDM isolated from littermate controls. Overall, our findings reveal that selective Bscl2 deficiency in macrophages does not critically impact the innate immune response to infection. Instead, an increased susceptibility to infection in CGL2 patients is likely to result from severe metabolic disease.
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McGrath C, Little-Letsinger SE, Sankaran JS, Sen B, Xie Z, Styner MA, Zong X, Chen W, Rubin J, Klett EL, Coleman RA, Styner M. Exercise Increases Bone in SEIPIN Deficient Lipodystrophy, Despite Low Marrow Adiposity. Front Endocrinol (Lausanne) 2021; 12:782194. [PMID: 35145475 PMCID: PMC8822583 DOI: 10.3389/fendo.2021.782194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 12/20/2021] [Indexed: 01/12/2023] Open
Abstract
Exercise, typically beneficial for skeletal health, has not yet been studied in lipodystrophy, a condition characterized by paucity of white adipose tissue, with eventual diabetes, and steatosis. We applied a mouse model of global deficiency of Bscl2 (SEIPIN), required for lipid droplet formation. Male twelve-week-old B6 knockouts (KO) and wild type (WT) littermates were assigned six-weeks of voluntary, running exercise (E) versus non-exercise (N=5-8). KO weighed 14% less than WT (p=0.01) and exhibited an absence of epididymal adipose tissue; KO liver Plin1 via qPCR was 9-fold that of WT (p=0.04), consistent with steatosis. Bone marrow adipose tissue (BMAT), unlike white adipose, was measurable, although 40.5% lower in KO vs WT (p=0.0003) via 9.4T MRI/advanced image analysis. SEIPIN ablation's most notable effect marrow adiposity was in the proximal femoral diaphysis (-56% KO vs WT, p=0.005), with relative preservation in KO-distal-femur. Bone via μCT was preserved in SEIPIN KO, though some quality parameters were attenuated. Running distance, speed, and time were comparable in KO and WT. Exercise reduced weight (-24% WT-E vs WT p<0.001) but not in KO. Notably, exercise increased trabecular BV/TV in both (+31%, KO-E vs KO, p=0.004; +14%, WT-E vs WT, p=0.006). The presence and distribution of BMAT in SEIPIN KO, though lower than WT, is unexpected and points to a uniqueness of this depot. That trabecular bone increases were achievable in both KO and WT, despite a difference in BMAT quantity/distribution, points to potential metabolic flexibility during exercise-induced skeletal anabolism.
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Affiliation(s)
- Cody McGrath
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Sarah E. Little-Letsinger
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Jeyantt Srinivas Sankaran
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Buer Sen
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Zhihui Xie
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Martin A. Styner
- Department of Psychiatry, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Computer Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Xiaopeng Zong
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Weiqin Chen
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Janet Rubin
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- North Carolina Diabetes Research Center (NCDRC), Chapel Hill, NC, United States
| | - Eric L. Klett
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- North Carolina Diabetes Research Center (NCDRC), Chapel Hill, NC, United States
- Department of Nutrition, Gillings School of Global Public Health, UNC, Chapel Hill, NC, United States
| | - Rosalind A. Coleman
- Department of Nutrition, Gillings School of Global Public Health, UNC, Chapel Hill, NC, United States
| | - Maya Styner
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- North Carolina Diabetes Research Center (NCDRC), Chapel Hill, NC, United States
- *Correspondence: Maya Styner,
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36
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Santos JL, Cortés VA. Eating behaviour in contrasting adiposity phenotypes: Monogenic obesity and congenital generalized lipodystrophy. Obes Rev 2021; 22:e13114. [PMID: 33030294 DOI: 10.1111/obr.13114] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 07/13/2020] [Indexed: 12/11/2022]
Abstract
Most known types of nonsyndromic monogenic obesity are caused by rare mutations in genes of the leptin-melanocortin pathway controlling appetite and adiposity. In contrast, congenital generalized lipodystrophy represents the most extreme form of leanness in humans caused by recessive mutations in four genes involved in phospholipid/triglyceride synthesis and lipid droplet/caveolae structure. In this disease, the inability to store triglyceride in adipocytes results in hypoleptinemia and ectopic hepatic and muscle fat accumulation leading to fatty liver, hypertriglyceridemia and severe insulin resistance. As a result of hypoleptinemia, patients with lipodystrophy show alterations in eating behaviour characterized by constant increased energy intake. As it occurs in obesity caused by genetic leptin deficiency, exogenous leptin rapidly reduces hunger scores in patients with congenital generalized lipodystrophy, with additional beneficial effects on glucose homeostasis and metabolic profile normalization. The melanocortin-4 receptor agonist setmelanotide has been used in the treatment of monogenic obesities. There is only one report on the effect of setmelanotide in a patient with partial lipodystrophy resulting in mild reductions in hunger scores, with no improvements in metabolic status. The assessment of contrasting phenotypes of obesity/leanness represents an adequate strategy to understand the pathophysiology and altered eating behaviour associated with adipose tissue excessive accumulation/paucity.
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Affiliation(s)
- José L Santos
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Víctor A Cortés
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
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37
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Jin Y, Tan Y, Zhao P, Ren Z. SEIPIN: A Key Factor for Nuclear Lipid Droplet Generation and Lipid Homeostasis. Int J Mol Sci 2020; 21:ijms21218208. [PMID: 33147895 PMCID: PMC7663086 DOI: 10.3390/ijms21218208] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/27/2020] [Accepted: 10/28/2020] [Indexed: 12/28/2022] Open
Abstract
Lipid homeostasis is essential for normal cell physiology. Generally, lipids are stored in a lipid droplet (LD), a ubiquitous organelle consisting of a neutral lipid core and a single layer of phospholipid membrane. It is thought that LDs are generated from the endoplasmic reticulum and then released into the cytosol. Recent studies indicate that LDs can exist in the nucleus, where they play an important role in the maintenance of cell phospholipid homeostasis. However, the details of nuclear lipid droplet (nLD) generation have not yet been clearly characterized. SEIPIN is a nonenzymatic protein encoded by the Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2) gene. It is associated with lipodystrophy diseases. Many recent studies have indicated that SEIPIN is essential for LDs generation. Here, we review much of this research in an attempt to explain the role of SEIPIN in nLD generation. From an integrative perspective, we conclude by proposing a theoretical model to explain how SEIPIN might participate in maintaining homeostasis of lipid metabolism.
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Affiliation(s)
- Yi Jin
- Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of the Ministry of Education & Key Laboratory of Swine Genetics and Breeding of the Ministry of Agriculture and Rural Affairs, College of Animal Science, Huazhong Agricultural University, Wuhan 430070, Hubei, China; (Y.J.); (Y.T.); (P.Z.)
- Bio-Medical Center of Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Yanjie Tan
- Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of the Ministry of Education & Key Laboratory of Swine Genetics and Breeding of the Ministry of Agriculture and Rural Affairs, College of Animal Science, Huazhong Agricultural University, Wuhan 430070, Hubei, China; (Y.J.); (Y.T.); (P.Z.)
- Institute of Biomedical Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, College of Life Sciences, Shandong Normal University, Jinan 250014, Shandong, China
| | - Pengxiang Zhao
- Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of the Ministry of Education & Key Laboratory of Swine Genetics and Breeding of the Ministry of Agriculture and Rural Affairs, College of Animal Science, Huazhong Agricultural University, Wuhan 430070, Hubei, China; (Y.J.); (Y.T.); (P.Z.)
| | - Zhuqing Ren
- Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of the Ministry of Education & Key Laboratory of Swine Genetics and Breeding of the Ministry of Agriculture and Rural Affairs, College of Animal Science, Huazhong Agricultural University, Wuhan 430070, Hubei, China; (Y.J.); (Y.T.); (P.Z.)
- Bio-Medical Center of Huazhong Agricultural University, Wuhan 430070, Hubei, China
- Correspondence:
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Salo VT, Hölttä-Vuori M, Ikonen E. Seipin-Mediated Contacts as Gatekeepers of Lipid Flux at the Endoplasmic Reticulum–Lipid Droplet Nexus. ACTA ACUST UNITED AC 2020. [DOI: 10.1177/2515256420945820] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Lipid droplets (LDs) are dynamic cellular hubs of lipid metabolism. While LDs contact a plethora of organelles, they have the most intimate relationship with the endoplasmic reticulum (ER). Indeed, LDs are initially assembled at specialized ER subdomains, and recent work has unraveled an increasing array of proteins regulating ER-LD contacts. Among these, seipin, a highly conserved lipodystrophy protein critical for LD growth and adipogenesis, deserves special attention. Here, we review recent insights into the role of seipin in LD biogenesis and as a regulator of ER-LD contacts. These studies have also highlighted the evolving concept of ER and LDs as a functional continuum for lipid partitioning and pinpointed a role for seipin at the ER-LD nexus in controlling lipid flux between these compartments.
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Affiliation(s)
- Veijo T. Salo
- Department of Anatomy and Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki
- Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Maarit Hölttä-Vuori
- Department of Anatomy and Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki
- Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Elina Ikonen
- Department of Anatomy and Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki
- Minerva Foundation Institute for Medical Research, Helsinki, Finland
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39
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Hoa Chung L, Qi Y. Lipodystrophy - A Rare Condition with Serious Metabolic Abnormalities. Rare Dis 2020. [DOI: 10.5772/intechopen.88667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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40
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Zhou H, Xu C, Lee H, Yoon Y, Chen W. Berardinelli-Seip congenital lipodystrophy 2/SEIPIN determines brown adipose tissue maintenance and thermogenic programing. Mol Metab 2020; 36:100971. [PMID: 32246911 PMCID: PMC7136632 DOI: 10.1016/j.molmet.2020.02.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 02/18/2020] [Accepted: 02/25/2020] [Indexed: 01/12/2023] Open
Abstract
Objective Understanding the mechanisms that control brown adipose tissue (BAT) mass and functionality is crucial for our understanding of how the disruption of energy homeostasis leads to obesity. Bernerdinali Seip Congenital Lipodystrophy (BSCL) type 2 (BSCL2, a.k.a. SEIPIN), a lipodystrophy-associated protein, has been shown to not be required for brown adipogenesis, but it has been shown to be essential for perinatal BAT development. However, its role in mature BAT maintenance and thermogenic programing remains poorly understood. Methods We subjected Bscl2f/f and Bscl2UCP1-BKO (BKO) mice with a brown adipose-specific loss of BSCL2 through UCP1 promoter-driven Cre to environmental, pharmacological and diet interventions to challenge BAT functionality and reprogramming. We carried out physiological, molecular and transcriptomic analyses of BAT. Results The deletion of BSCL2 in mature brown adipocytes increased sympathetic nervous system-independent cAMP/protein kinase A (PKA) signaling in BAT. Such activation reduced BAT triglyceride content and mass and was sufficient to reduce plasma triglyceride, but not enough to combat thermoneutral and high fat diet-induced obesity. Surprisingly, BKO mice displayed an impaired response to acute and chronic cold challenges despite cAMP/PKA activation. When subjected to chronic cold exposure or the administration of a β3-adrenergic agonist, CL 316,243, BKO mice failed to induce BAT recruitment and underwent dramatic brown adipocyte loss. Transcriptomic analysis revealed pathological BAT remodeling with inflammation and fibrosis, which was further exacerbated by a chronic thermogenic challenge in BKO mice. Mechanistically, we found abnormal mitochondrial shapes and function in BAT of BKO mice housed at 21 °C; as well as mitochondrial DNA depletion and necroptotic-mediated brown adipocyte death after chronic thermogenic insult. Conclusion BSCL2-mediated lipid catabolism within BAT is crucial for mature brown adipocyte function and survival both during times of activation and quiescence. BSCL2 is an important regulator of mature brown adipocyte mitochondrial metabolism, necroptosis and thus adaptive thermogenesis. Mature BAT-specific loss of BSCL2 (Bscl2UCP1-BKO) activates SNS-independent cAMP/PKA signaling. Bscl2UCP1-BKO increases BAT mitochondrial fission and uncoupling. Bscl2UCP1-BKO reduces plasma triglyceride but not adiposity under thermoneutrality or high fat diet. Bscl2UCP1-BKO blunts BAT reprograming and causes cold intolerance. BSCL2 deletion exposes brown adipocyte to necroptosis under chronic thermogenic stress.
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Affiliation(s)
- Hongyi Zhou
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Cheng Xu
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Hakjoo Lee
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Yisang Yoon
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Weiqin Chen
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA.
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Xiong J, Sun P, Wang Y, Hua X, Song W, Wang Y, Wu J, Yu W, Liu G, Chen L. Heterozygous deletion of Seipin in islet beta cells of male mice has an impact on insulin synthesis and secretion through reduced PPARγ expression. Diabetologia 2020; 63:338-350. [PMID: 31776610 DOI: 10.1007/s00125-019-05038-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 10/03/2019] [Indexed: 12/11/2022]
Abstract
AIMS/HYPOTHESIS Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2) is an autosomal recessive disorder characterised by lipodystrophy and insulin resistance. BSCL2 is caused by loss-of-function mutations in the Seipin gene (also known as Bscl2). Deletion of this gene in mice induces insulin resistance, glucose intolerance and a loss of adipose tissue. This study evaluated the effects of genetic deletion of Seipin on islet beta cell function. METHODS We examined seipin expression in islet cells and measured glucose profiles, insulin synthesis, glucose-stimulated insulin secretion (GSIS), islet expression of peroxisome proliferator-activated receptor γ (PPARγ), levels of Pdx-1, Nkx6.1, Glut2 (also known as Slc2a2) and proinsulin mRNA, nuclear translocation of pancreatic duodenal homeobox 1 (PDX-1), islet numbers, and beta cell mass and proliferation in male and female Seipin-knockout homozygous (Seipin-/-) and heterozygous (Seipin+/-) mice. RESULTS Male and female Seipin-/- mice displayed glucose intolerance, insulin resistance, hyperinsulinaemia and a lack of adipose tissue. By contrast, male but not female Seipin+/- mice showed glucose intolerance without adipose tissue loss or insulin resistance. Seipin was highly expressed in islet beta cells in wild-type mice. Expression of islet PPARγ was reduced in male Seipin-/- and Seipin+/- mice but not in female Seipin-/- or Seipin+/- mice. Treatment of male Seipin+/- mice with rosiglitazone corrected the glucose intolerance. Male Seipin+/- mice displayed a decrease in islet insulin concentration and GSIS with low expression of Pdx-1, Nkx6.1, Glut2 and proinsulin, and a decline in PDX-1 nuclear translocation; these changes were rescued by rosiglitazone administration. Male Seipin-/- mice showed obvious, but rosiglitazone-sensitive, increases in islet insulin concentration, islet number and beta cell mass and proliferation, with a notable decline in GSIS. Ovariectomised female Seipin+/- mice displayed glucose intolerance and deficits in insulin synthesis and secretion, with a decline in islet PPARγ level; these deleterious effects were reversed by administration of oestradiol or rosiglitazone. CONCLUSIONS/INTERPRETATION Heterozygous deletion of Seipin in islet beta cells impacts on insulin synthesis and secretion through reduced PPARγ expression. This leads to glucose intolerance and is relieved by oestradiol, which rescues PPARγ expression.
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Affiliation(s)
- Jianwei Xiong
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| | - Peng Sun
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China
| | - Ya Wang
- Department of Physiology, Nanjing Medical University, Longmian Road 101, Nanjing, 211166, China
| | - Xu Hua
- Department of Physiology, Nanjing Medical University, Longmian Road 101, Nanjing, 211166, China
| | - Wenyu Song
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China
| | - Yan Wang
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China
| | - Jie Wu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| | - Wenfeng Yu
- Key Laboratory of Medical Molecular Biology, Guizhou Medical University, Guiyang, 550004, China.
| | - George Liu
- Institute of Cardiovascular Sciences, Peking University and Key Laboratory of Cardiovascular Sciences, China Administration of Education, Beijing, 100191, China.
| | - Ling Chen
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China.
- Department of Physiology, Nanjing Medical University, Longmian Road 101, Nanjing, 211166, China.
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Mcilroy GD, Mitchell SE, Han W, Delibegović M, Rochford JJ. Ablation of Bscl2/seipin in hepatocytes does not cause metabolic dysfunction in congenital generalised lipodystrophy. Dis Model Mech 2020; 13:dmm.042655. [PMID: 31848133 PMCID: PMC6994952 DOI: 10.1242/dmm.042655] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 12/10/2019] [Indexed: 12/19/2022] Open
Abstract
Mutations affecting the BSCL2 gene cause the most severe form of congenital generalised lipodystrophy (CGL). Affected individuals develop severe metabolic complications including diabetes and hepatic steatosis. Bscl2-deficient mice almost entirely reproduce the CGL phenotype. Adipose tissue-specific loss of Bscl2 is also sufficient to cause early-onset generalised lipodystrophy in mice. However, these mice do not show severe metabolic dysfunction, even when challenged with a high-fat diet. Germline Bscl2 loss in mice and BSCL2 disruption in humans causes severe hepatic steatosis, and the encoded protein, seipin, has acknowledged roles in lipid accumulation. Given the critical role of the liver in glucose regulation, we speculated that intact hepatic Bscl2 expression may protect adipose tissue-specific Bscl2-deficient mice from metabolic disease. To investigate this, we generated a novel mouse model in which Bscl2 has been deleted in both adipose tissue and hepatocytes simultaneously using an adeno-associated viral vector. Despite achieving efficient disruption of Bscl2 in the liver, hepatic lipid accumulation and metabolic homeostasis was unaffected in mice fed a high-fat diet for 4 weeks. We also investigated the consequences of BSCL2 ablation in the human hepatocyte HepG2 cell line using CRISPR/Cas9 genome editing. No significant increases in lipid accumulation were observed in BSCL2 knockout cell lines. Overall, we reveal that Bscl2/BSCL2 does not appear to play a cell-autonomous role in the regulation of lipid accumulation in the liver. Loss of hepatic BSCL2 is therefore unlikely to contribute significantly to the development of hepatic steatosis or metabolic dysfunction in this form of CGL. Editor's choice: Hepatic Bscl2 ablation in adipose tissue-specific Bscl2 knockout mice does not cause metabolic dysfunction. CRISPR/Cas9 genome editing reveals that seipin does not play a cell-autonomous role in regulating hepatocyte lipid accumulation.
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Affiliation(s)
- George D Mcilroy
- The Rowett Institute, University of Aberdeen, Aberdeen AB25 2ZD, UK .,Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Sharon E Mitchell
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Weiping Han
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), Singapore 138667
| | - Mirela Delibegović
- Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Aberdeen AB25 2ZD, UK.,Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Justin J Rochford
- The Rowett Institute, University of Aberdeen, Aberdeen AB25 2ZD, UK.,Aberdeen Cardiovascular and Diabetes Centre, University of Aberdeen, Aberdeen AB25 2ZD, UK
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Changes in redox and endoplasmic reticulum homeostasis are related to congenital generalized lipodystrophy type 2. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158610. [PMID: 31917334 DOI: 10.1016/j.bbalip.2020.158610] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 12/23/2019] [Accepted: 12/31/2019] [Indexed: 12/27/2022]
Abstract
CGL type 2 is a rare autosomal recessive syndrome characterized by an almost complete lack of body fat. CGL is caused by loss-of-function mutations in both alleles of the BSCL2 gene that codifies to seipin. Subjects often show hyperglycemia, decreased HDL-c, and hypoadiponectinemia. These laboratory findings are important triggers for changes in redox and ER homeostasis. Therefore, our aim was to investigate whether these intracellular mechanisms are associated with this syndrome. We collected blood from people from Northeastern Brazil with 0, 1, and 2 mutant alleles for the rs786205071 in the BSCL2 gene. Through the qPCR technique, we evaluated the expression of genes responsible for triggering the antioxidant response, DNA repair, and ER stress in leukocytes. Colorimetric tests were applied to quantify lipid peroxidation and to evaluate the redox status of glutathione, as well as to access the panorama of energy metabolism. Long extension PCR was performed to observe leukocyte mitochondrial DNA lesions, and the immunoblot technique to investigate plasma adiponectin concentrations. Subjects with the rs786205071 in both BSCL2 alleles showed increased transcription of NFE2L2, APEX1, and OGG1 in leukocytes, as well as high concentrations of malondialdehyde and the GSSG:GSH ratio in plasma. We also observed increase of mitochondrial DNA lesions and XBP1 splicing, as well as a decrease in adiponectin and HDL-c. Our data suggest the presence of lipid lesions due to changes in redox homeostasis in that group, associated with increased levels of mitochondrial DNA damage and transcriptional activation of genes involved with antioxidant response and DNA repair.
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Liu L, Liang C, Wang X, Ding X, Lu Y, Dong J, Han M, Yang H, Gao M, Liao J. Surgical fat removal exacerbates metabolic disorders but not atherogenesis in LDLR -/- mice fed on high-fat diet. Sci Rep 2019; 9:17848. [PMID: 31780791 PMCID: PMC6883051 DOI: 10.1038/s41598-019-54392-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 11/12/2019] [Indexed: 01/17/2023] Open
Abstract
Lipodystrophy is a severe adipose dysfunction that can be classified as congenital or acquired lipodystrophy, in term of the etiology. Previous knowledge about the metabolic disorders and cardiovascular consequences were mostly obtained from lipodystrophic mice with genetic defects. To completely rule out the genetic influence, we established a mouse model of acquired generalized lipodystrophy by surgical removal of multiple fat depots, including subcutaneous fat in the inguinal, visceral fat in the epididymis and brown fat in the scapula, in atherosclerosis-prone LDLR-/- mice which were fed with a high-fat diet (HFD). It was observed that fat removal increased diet-induced hyperlipidemia, especially hypercholesteremia, as early as 2 weeks after HFD and till the end of HFD feeding. After 12 weeks on the HFD, the residual fats of fat-removed mice were found expanded. Although fat removal aggravated diet-induced lipid deposition in the liver and systemic insulin resistance, there was no significant difference in atherogenesis in fat-removed mice compared with sham-operated control mice. Acquired generalized lipodystrophy by surgical fat removal promoted metabolic disorders but not atherogenesis in LDLR-/- mice fed on HFD.
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Affiliation(s)
- Lin Liu
- Laboratory of Lipid Metabolism, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei, 050017, China
| | - Chenxi Liang
- Laboratory of Lipid Metabolism, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei, 050017, China
| | - Xiaowei Wang
- Laboratory of Lipid Metabolism, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei, 050017, China
| | - Xiayu Ding
- Laboratory of Lipid Metabolism, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei, 050017, China
| | - Yingjing Lu
- Laboratory of Lipid Metabolism, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei, 050017, China
| | - Jinghui Dong
- Department of Physiology, Hebei Medical University, Shijiazhuang, Hebei, 050017, China
| | - Mei Han
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Key Laboratory of Medical Biotechnology of Hebei Province, Hebei Medical University, Shijiazhuang, Hebei, 050017, China
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Mingming Gao
- Laboratory of Lipid Metabolism, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei, 050017, China.
| | - Jiawei Liao
- Department of Cardiology, Institute of Cardiovascular Diseases, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, 116011, China.
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Complexity of Generating Mouse Models to Study the Upper Motor Neurons: Let Us Shift Focus from Mice to Neurons. Int J Mol Sci 2019; 20:ijms20163848. [PMID: 31394733 PMCID: PMC6720674 DOI: 10.3390/ijms20163848] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 07/26/2019] [Accepted: 08/05/2019] [Indexed: 12/11/2022] Open
Abstract
Motor neuron circuitry is one of the most elaborate circuitries in our body, which ensures voluntary and skilled movement that requires cognitive input. Therefore, both the cortex and the spinal cord are involved. The cortex has special importance for motor neuron diseases, in which initiation and modulation of voluntary movement is affected. Amyotrophic lateral sclerosis (ALS) is defined by the progressive degeneration of both the upper and lower motor neurons, whereas hereditary spastic paraplegia (HSP) and primary lateral sclerosis (PLS) are characterized mainly by the loss of upper motor neurons. In an effort to reveal the cellular and molecular basis of neuronal degeneration, numerous model systems are generated, and mouse models are no exception. However, there are many different levels of complexities that need to be considered when developing mouse models. Here, we focus our attention to the upper motor neurons, which are one of the most challenging neuron populations to study. Since mice and human differ greatly at a species level, but the cells/neurons in mice and human share many common aspects of cell biology, we offer a solution by focusing our attention to the affected neurons to reveal the complexities of diseases at a cellular level and to improve translational efforts.
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46
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The biogenesis of lipid droplets: Lipids take center stage. Prog Lipid Res 2019; 75:100989. [PMID: 31351098 DOI: 10.1016/j.plipres.2019.100989] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 05/21/2019] [Accepted: 06/27/2019] [Indexed: 11/20/2022]
Abstract
Lipid droplets (LDs) are multi-functional cellular organelles that store energy, and regulate many aspects of cell physiology. However, our understanding of the biogenesis of LDs remains very limited. Originating from the endoplasmic reticulum (ER), LDs are highly unique organelles in that each LD is bounded by a monolayer of amphipathic lipids. Recent progress has unveiled critical roles of non-bilayer lipids in LD formation. For instance, non-bilayer lipids such as lysophospholipids, diacylglycerol and phosphatidic acid (PA) can impact the curvature, surface and line tension of the ER, thereby impacting LD biogenesis. Two well-known regulators of LD formation, FIT2/FITM2 and seipin, have both been implicated in controlling the metabolism and/or distribution of non-bilayer lipids. We summarize and integrate these recent advances and propose that non-bilayer lipids may play a critical role in each step of LD biogenesis.
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Polyzos SA, Perakakis N, Mantzoros CS. Fatty liver in lipodystrophy: A review with a focus on therapeutic perspectives of adiponectin and/or leptin replacement. Metabolism 2019; 96:66-82. [PMID: 31071311 DOI: 10.1016/j.metabol.2019.05.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/23/2019] [Accepted: 05/03/2019] [Indexed: 01/17/2023]
Abstract
Lipodystrophy is a group of clinically heterogeneous, inherited or acquired, disorders characterized by complete or partial absence of subcutaneous adipose tissue that may occur simultaneously with the pathological, ectopic, accumulation of fat in other regions of the body, including the liver. Fatty liver adds significantly to hepatic and extra-hepatic morbidity in patients with lipodystrophy. Lipodystrophy is strongly associated with severe insulin resistance and related comorbidities, such as hyperglycemia, hyperlipidemia and nonalcoholic fatty liver disease (NAFLD), but other hepatic diseases may co-exist in some types of lipodystrophy, including autoimmune hepatitis in acquired lipodystrophies, or viral hepatitis in human immunodeficiency virus (HIV)-associated lipodystrophy. The aim of this review is to summarize evidence linking lipodystrophy with hepatic disease and to provide a special focus on potential therapeutic perspectives of leptin replacement therapy and adiponectin upregulation in lipodystrophy.
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Affiliation(s)
- Stergios A Polyzos
- First Department of Pharmacology, Faculty of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
| | - Nikolaos Perakakis
- Department of Internal Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Christos S Mantzoros
- Department of Internal Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Section of Endocrinology, Boston VA Healthcare System, Harvard Medical School, Boston, MA, USA
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Zhou H, Lei X, Yan Y, Lydic T, Li J, Weintraub NL, Su H, Chen W. Targeting ATGL to rescue BSCL2 lipodystrophy and its associated cardiomyopathy. JCI Insight 2019; 5:129781. [PMID: 31185001 DOI: 10.1172/jci.insight.129781] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Mutations in BSCL2 gene underlie human type 2 Berardinelli-Seip Congenital Lipodystrophy (BSCL2) disease. Global Bscl2-/- mice recapitulate human BSCL2 lipodystrophy and develop insulin resistance and hypertrophic cardiomyopathy. The pathological mechanisms underlying the development of lipodystrophy and cardiomyopathy in BSCL2 are controversial. Here we report that Bscl2-/- mice develop cardiac hypertrophy due to increased basal IGF1 receptor (IGF1R)-mediated PI3K/AKT signaling. Bscl2-/- hearts exhibited increased adipose triglyceride lipase (ATGL) protein stability and expression causing drastic reduction of glycerolipids. Excessive fatty acid oxidation was overt in Bscl2-/- hearts, partially attributing to the hyperacetylation of cardiac mitochondrial proteins. Intriguingly, pharmacological inhibition or genetic inactivation of ATGL could rescue adipocyte differentiation and lipodystrophy in Bscl2-/- cells and mice. Restoring a small portion of fat mass by ATGL partial deletion in Bscl2-/- mice not only reversed the systemic insulin resistance, but also ameliorated cardiac protein hyperacetylation, normalized cardiac substrate metabolism and improved contractile function. Collectively, our study uncovers novel pathways underlying lipodystrophy-induced cardiac hypertrophy and metabolic remodeling and pinpoints ATGL as a downstream target of BSCL2 in regulating the development of lipodystrophy and its associated cardiomyopathy.
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Affiliation(s)
- Hongyi Zhou
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Xinnuo Lei
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Yun Yan
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Todd Lydic
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
| | - Jie Li
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Neal L Weintraub
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Huabo Su
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Weiqin Chen
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
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Salo VT, Li S, Vihinen H, Hölttä-Vuori M, Szkalisity A, Horvath P, Belevich I, Peränen J, Thiele C, Somerharju P, Zhao H, Santinho A, Thiam AR, Jokitalo E, Ikonen E. Seipin Facilitates Triglyceride Flow to Lipid Droplet and Counteracts Droplet Ripening via Endoplasmic Reticulum Contact. Dev Cell 2019; 50:478-493.e9. [PMID: 31178403 DOI: 10.1016/j.devcel.2019.05.016] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 02/27/2019] [Accepted: 05/03/2019] [Indexed: 01/02/2023]
Abstract
Seipin is an oligomeric integral endoplasmic reticulum (ER) protein involved in lipid droplet (LD) biogenesis. To study the role of seipin in LD formation, we relocalized it to the nuclear envelope and found that LDs formed at these new seipin-defined sites. The sites were characterized by uniform seipin-mediated ER-LD necks. At low seipin content, LDs only grew at seipin sites, and tiny, growth-incompetent LDs appeared in a Rab18-dependent manner. When seipin was removed from ER-LD contacts within 1 h, no lipid metabolic defects were observed, but LDs became heterogeneous in size. Studies in seipin-ablated cells and model membranes revealed that this heterogeneity arises via a biophysical ripening process, with triglycerides partitioning from smaller to larger LDs through droplet-bilayer contacts. These results suggest that seipin supports the formation of structurally uniform ER-LD contacts and facilitates the delivery of triglycerides from ER to LDs. This counteracts ripening-induced shrinkage of small LDs.
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Affiliation(s)
- Veijo T Salo
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Shiqian Li
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Helena Vihinen
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Maarit Hölttä-Vuori
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | | | | | - Ilya Belevich
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Johan Peränen
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | | | - Pentti Somerharju
- Department of Biochemistry, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Hongxia Zhao
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Alexandre Santinho
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Universite de Paris, Paris, France
| | - Abdou Rachid Thiam
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Universite de Paris, Paris, France.
| | - Eija Jokitalo
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
| | - Elina Ikonen
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland.
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Gilardi F, Winkler C, Quignodon L, Diserens JG, Toffoli B, Schiffrin M, Sardella C, Preitner F, Desvergne B. Systemic PPARγ deletion in mice provokes lipoatrophy, organomegaly, severe type 2 diabetes and metabolic inflexibility. Metabolism 2019; 95:8-20. [PMID: 30878493 DOI: 10.1016/j.metabol.2019.03.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 02/27/2019] [Accepted: 03/12/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND The peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-dependent transcription factor involved in many aspects of metabolism, immune response and development. Numerous studies relying on tissue-specific invalidation of the Pparg gene have shown distinct facets of its activity, whereas the effects of its systemic inactivation remain unexplored due to embryonic lethality. By maintaining PPARγ expression in the placenta, we recently generated a mouse model carrying Pparg full body deletion (PpargΔ/Δ), which in contrast to a previously published model is totally deprived of any form of adipose tissue. Herein, we propose an in-depth study of the metabolic alterations observed in this new model. METHODS Young adult mice, both males and females analyzed separately, were first phenotyped for their gross anatomical alterations. Systemic metabolic parameters were analyzed in the blood, in static and in dynamic conditions. A full exploration of energy metabolism was performed in calorimetric cages as well as in metabolic cages. Our study was completed by expression analyses of a set of specific genes. MAIN FINDINGS PpargΔ/Δ mice show a striking complete absence of any form of adipose tissue, which triggers a complex metabolic phenotype including increased lean mass with organomegaly, hypermetabolism, urinary energy loss, hyperphagia, and increased amino acid metabolism. PpargΔ/Δ mice develop severe type 2 diabetes, characterized by hyperglycemia, hyperinsulinemia, polyuria and polydispsia. They show a remarkable metabolic inflexibility, as indicated by the inability to shift substrate oxidation between glucose and lipids, in both ad libitum fed state and fed/fasted/refed transitions. Moreover, upon fasting PpargΔ/Δ mice enter a severe hypometabolic state. CONCLUSIONS Our data comprehensively describe the impact of lipoatrophy on metabolic homeostasis. As such, the presented data on PpargΔ/Δ mice gives new clues on what and how to explore severe lipodystrophy and its subsequent metabolic complications in human.
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Affiliation(s)
- Federica Gilardi
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland.
| | - Carine Winkler
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Laure Quignodon
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Jean-Gael Diserens
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Barbara Toffoli
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Mariano Schiffrin
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Chiara Sardella
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Frédéric Preitner
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Béatrice Desvergne
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland.
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