1
|
Tang Y, Majewska M, Leß B, Mehmeti I, Wollnitzke P, Semleit N, Levkau B, Saba JD, van Echten-Deckert G, Gurgul-Convey E. The fate of intracellular S1P regulates lipid droplet turnover and lipotoxicity in pancreatic beta-cells. J Lipid Res 2024:100587. [PMID: 38950680 DOI: 10.1016/j.jlr.2024.100587] [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: 12/19/2023] [Revised: 06/07/2024] [Accepted: 06/22/2024] [Indexed: 07/03/2024] Open
Abstract
Lipotoxicity has been considered the main cause of pancreatic beta-cell failure during type 2 diabetes development. Lipid droplets (LD) are believed to regulate the beta-cell sensitivity to free fatty acids (FFA), but the underlying molecular mechanisms are largely unclear. Accumulating evidence points, however, to an important role of intracellular sphingosine-1-phosphate (S1P) metabolism in lipotoxicity-mediated disturbances of beta-cell function. In the present study, we compared the effects of an increased irreversible S1P degradation (S1P-lyase, SPL overexpression) with those associated with an enhanced S1P recycling (overexpression of S1P phosphatase 1, SGPP1) on LD formation and lipotoxicity in rat INS1E beta-cells. Interestingly, although both approaches led to a reduced S1P concentration, they had opposite effects on the susceptibility to FFA. Overexpression of SGPP1 prevented FFA-mediated caspase-3 activation by a mechanism involving an enhanced lipid storage capacity and prevention of oxidative stress. In contrast, SPL overexpression limited lipid droplet biogenesis, content and size, while accelerating lipophagy. This was associated with FFA-induced hydrogen peroxide formation, mitochondrial fragmentation and dysfunction, as well as ER stress. These changes coincided with upregulation of proapoptotic ceramides, but were independent of lipid peroxidation rate. Also in human EndoC-βH1 beta-cells suppression of SPL with simultaneous overexpression of SGPP1 led to a similar and even more pronounced LD phenotype as that in INS1E-SGPP1 cells. Thus, intracellular S1P turnover significantly regulates LD content and size, and influences beta-cell sensitivity to FFA.
Collapse
Affiliation(s)
- Yadi Tang
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Mariola Majewska
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Britta Leß
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Ilir Mehmeti
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Philipp Wollnitzke
- Institute of Molecular Medicine III, University Hospital Düsseldorf and Heinrich Heine University, Düsseldorf, Germany
| | - Nina Semleit
- Institute of Molecular Medicine III, University Hospital Düsseldorf and Heinrich Heine University, Düsseldorf, Germany
| | - Bodo Levkau
- Institute of Molecular Medicine III, University Hospital Düsseldorf and Heinrich Heine University, Düsseldorf, Germany
| | - Julie D Saba
- University of California, San Francisco, Oakland, CA, USA
| | | | - Ewa Gurgul-Convey
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
| |
Collapse
|
2
|
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.
Collapse
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.
| |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
Lan ZQ, Ge ZY, Lv SK, Zhao B, Li CX. The regulatory role of lipophagy in central nervous system diseases. Cell Death Discov 2023; 9:229. [PMID: 37414782 DOI: 10.1038/s41420-023-01504-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/04/2023] [Accepted: 06/19/2023] [Indexed: 07/08/2023] Open
Abstract
Lipid droplets (LDs) are the organelles for storing neutral lipids, which are broken down when energy is insufficient. It has been suggested that excessive accumulation of LDs can affect cellular function, which is important to coordinate homeostasis of lipids in vivo. Lysosomes play an important role in the degradation of lipids, and the process of selective autophagy of LDs through lysosomes is known as lipophagy. Dysregulation of lipid metabolism has recently been associated with a variety of central nervous system (CNS) diseases, but the specific regulatory mechanisms of lipophagy in these diseases remain to be elucidated. This review summarizes various forms of lipophagy and discusses the role that lipophagy plays in the development of CNS diseases in order to reveal the related mechanisms and potential therapeutic targets for these diseases.
Collapse
Affiliation(s)
- Zhuo-Qing Lan
- Department of General practice medicine, the Fourth Affiliated Hospital, School of Medicine, Zhejiang University, Yiwu, P.R. China
| | - Zi-Yi Ge
- Department of Anesthesiology, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, P.R. China
| | - Shu-Kai Lv
- Department of General practice medicine, the Fourth Affiliated Hospital, School of Medicine, Zhejiang University, Yiwu, P.R. China
| | - Bing Zhao
- Department of Anesthesiology, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, P.R. China.
| | - Cai-Xia Li
- Department of General practice medicine, the Fourth Affiliated Hospital, School of Medicine, Zhejiang University, Yiwu, P.R. China.
- Department of Anesthesiology, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, P.R. China.
| |
Collapse
|
5
|
Shen WJ, Cortez Y, Singh A, Chen W, Azhar S, Kraemer FB. Mice deficient in ER protein seipin have reduced adrenal cholesteryl ester lipid droplet formation and utilization. J Lipid Res 2022; 63:100309. [PMID: 36332685 PMCID: PMC9703635 DOI: 10.1016/j.jlr.2022.100309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/28/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022] Open
Abstract
Cholesteryl ester (CE)-rich lipid droplets (LDs) accumulate in steroidogenic tissues under physiological conditions and constitute an important source of cholesterol as the precursor for the synthesis of all steroid hormones. The mechanisms specifically involved in CE-rich LD formation have not been directly studied and are assumed by most to occur in a fashion analogous to triacylglycerol-rich LDs. Seipin is an endoplasmic reticulum protein that forms oligomeric complexes at endoplasmic reticulum-LD contact sites, and seipin deficiency results in severe alterations in LD maturation and morphology as seen in Berardinelli-Seip congenital lipodystrophy type 2. While seipin is critical for triacylglycerol-rich LD formation, no studies have directly addressed whether seipin is important for CE-rich LD biogenesis. To address this issue, mice with deficient expression of seipin specifically in adrenal, testis, and ovary, steroidogenic tissues that accumulate CE-rich LDs under normal physiological conditions, were generated. We found that the steroidogenic-specific seipin-deficient mice displayed a marked reduction in LD and CE accumulation in the adrenals, demonstrating the pivotal role of seipin in CE-rich LD accumulation/formation. Moreover, the reduction in CE-rich LDs was associated with significant defects in adrenal and gonadal steroid hormone production that could not be completely reversed by addition of exogenous lipoprotein cholesterol. We conclude that seipin has a heretofore unappreciated role in intracellular cholesterol trafficking.
Collapse
Affiliation(s)
- Wen-Jun Shen
- Division of Endocrinology, Gerontology, and Metabolism, Stanford University, Stanford, CA, USA; Geriatric Research, Education, and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA.
| | - Yuan Cortez
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
| | - Amar Singh
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
| | - Weiqin Chen
- Department of Physiology, Augusta University, Augusta, GA, USA
| | - Salman Azhar
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
| | - Fredric B Kraemer
- Division of Endocrinology, Gerontology, and Metabolism, Stanford University, Stanford, CA, USA; Geriatric Research, Education, and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA.
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
Apte MS, Joshi AS. Membrane shaping proteins, lipids, and cytoskeleton: Recipe for nascent lipid droplet formation. Bioessays 2022; 44:e2200038. [PMID: 35832014 DOI: 10.1002/bies.202200038] [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: 02/15/2022] [Revised: 06/26/2022] [Accepted: 06/29/2022] [Indexed: 11/06/2022]
Abstract
Lipid droplets (LDs) are ubiquitous, neutral lipidorganelles that act as hubs of metabolic processes. LDs are structurally unique with a hydrophobic core that mainly consists of neutral lipids, sterol esters, and triglycerides, enclosed within a phospholipid monolayer. Nascent LD formation begins with the accumulation of neutral lipids in the endoplasmic reticulum (ER) bilayer. The ER membrane proteins such as seipin, LDAF1, FIT, and MCTPs are reported to play an important role in the formation of nascent LDs. As the LDs grow, they unmix from the highly charged ER membrane to form mature LDs. LD biogenesis is an exciting, emerging research area, and herein, we discuss the recent progress in our understanding of the formation of eukaryotic nascent LDs. We focus on the role of ER membrane shaping proteins such as reticulons and reticulon-like proteins, membrane lipids, and cytoskeleton proteins such as septin in the formation of nascent LDs.
Collapse
Affiliation(s)
- Manasi S Apte
- Department of Biochemistry & Cell and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Amit S Joshi
- Department of Biochemistry & Cell and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| |
Collapse
|
8
|
Kim S, Chung J, Arlt H, Pak AJ, Farese RV, Walther TC, Voth GA. Seipin transmembrane segments critically function in triglyceride nucleation and lipid droplet budding from the membrane. eLife 2022; 11:75808. [PMID: 35583926 PMCID: PMC9122495 DOI: 10.7554/elife.75808] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 04/22/2022] [Indexed: 11/24/2022] Open
Abstract
Lipid droplets (LDs) are organelles formed in the endoplasmic reticulum (ER) to store triacylglycerol (TG) and sterol esters. The ER protein seipin is key for LD biogenesis. Seipin forms a cage-like structure, with each seipin monomer containing a conserved hydrophobic helix and two transmembrane (TM) segments. How the different parts of seipin function in TG nucleation and LD budding is poorly understood. Here, we utilized molecular dynamics simulations of human seipin, along with cell-based experiments, to study seipin’s functions in protein–lipid interactions, lipid diffusion, and LD maturation. An all-atom simulation indicates that seipin TM segment residues and hydrophobic helices residues located in the phospholipid tail region of the bilayer attract TG. Simulating larger, growing LDs with coarse-grained models, we find that the seipin TM segments form a constricted neck structure to facilitate conversion of a flat oil lens into a budding LD. Using cell experiments and simulations, we also show that conserved, positively charged residues at the end of seipin’s TM segments affect LD maturation. We propose a model in which seipin TM segments critically function in TG nucleation and LD growth.
Collapse
Affiliation(s)
- Siyoung Kim
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, United States
| | - Jeeyun Chung
- Department of Molecular Metabolism, Harvard T H Chan School of Public Health, Boston, United States.,Department of Cell Biology, Harvard Medical School, Boston, United States
| | - Henning Arlt
- Department of Molecular Metabolism, Harvard T H Chan School of Public Health, Boston, United States.,Department of Cell Biology, Harvard Medical School, Boston, United States.,Howard Hughes Medical Institute, Harvard T H Chan School of Public Health, Boston, United States
| | - Alexander J Pak
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, United States
| | - Robert V Farese
- Department of Molecular Metabolism, Harvard T H Chan School of Public Health, Boston, United States.,Department of Cell Biology, Harvard Medical School, Boston, United States.,Broad Institute of Harvard and MIT, Cambridge, United States
| | - Tobias C Walther
- Department of Molecular Metabolism, Harvard T H Chan School of Public Health, Boston, United States.,Department of Cell Biology, Harvard Medical School, Boston, United States.,Howard Hughes Medical Institute, Harvard T H Chan School of Public Health, Boston, United States.,Broad Institute of Harvard and MIT, Cambridge, United States
| | - Gregory A Voth
- Department of Chemistry, Chicago Center for Theoretical Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, United States
| |
Collapse
|
9
|
Cao Z, Fung CW, Mak HY. A Flexible Network of Lipid Droplet Associated Proteins Support Embryonic Integrity of C. elegans. Front Cell Dev Biol 2022; 10:856474. [PMID: 35445028 PMCID: PMC9015696 DOI: 10.3389/fcell.2022.856474] [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: 01/17/2022] [Accepted: 03/16/2022] [Indexed: 11/13/2022] Open
Abstract
In addition to coordinating the storage and mobilization of neutral fat, lipid droplets (LDs) are conserved organelles that can accommodate additional cargos in order to support animal development. However, it is unclear if each type of cargo is matched with a specific subset of LDs. Here, we report that SEIP-1/seipin defines a subset of oocyte LDs that are required for proper eggshell formation in C. elegans. Using a photoconvertible fluorescent protein-based imaging assay, we found that SEIP-1 positive LDs were selectively depleted after fertilization, coincident of the formation of a lipid-rich permeability barrier of the eggshell. Loss of SEIP-1 function caused impenetrant embryonic arrest, which could be worsened by FAT-3/fatty acyl-CoA desaturase deficiency or suppressed by PLIN-1/Perilipin deficiency. The embryonic development of seip-1; plin-1 mutant in turn depended on the recruitment of RAB-18/Rab18 to LDs, which was not observed in wild type embryos. We propose that SEIP-1 dependent and independent mechanisms act in parallel to ensure the packaging and export of lipid-rich permeability barrier constituents, which involve LDs. The identity of these LDs, as defined by their associated proteins, exhibits unexpected plasticity that ultimately ensures the survival of embryos ex utero.
Collapse
Affiliation(s)
- Zhe Cao
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Chun Wing Fung
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Ho Yi Mak
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| |
Collapse
|
10
|
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.
Collapse
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.
| |
Collapse
|
11
|
Akinci G, Celik M, Akinci B. Complications of lipodystrophy syndromes. Presse Med 2021; 50:104085. [PMID: 34728268 DOI: 10.1016/j.lpm.2021.104085] [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: 07/04/2021] [Revised: 10/09/2021] [Accepted: 10/20/2021] [Indexed: 10/19/2022] Open
Abstract
Lipodystrophy syndromes are rare complex multisystem disorders caused by generalized or partial lack of adipose tissue. Adipose tissue dysfunction in lipodystrophy is associated with leptin deficiency. Lipodystrophy leads to severe metabolic problems. These abnormalities include, but are not limited to, insulin-resistant diabetes, severe hypertriglyceridemia, and lipid accumulation in ectopic organs such as the liver, and are associated with end-organ complications. Metabolic abnormalities can be present at the time of diagnosis or may develop over time as the disease progresses. In addition to metabolic abnormalities, subtype-specific presentations due to underlying molecular etiology in genetic forms and autoimmunity in acquired forms contribute to severe morbidity in lipodystrophy.
Collapse
Affiliation(s)
- Gulcin Akinci
- Division of Pediatric Neurology, Dr. Behcet Uz Children's Hospital, Izmir, Turkey
| | - Merve Celik
- Division of Endocrinology and Metabolism, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Baris Akinci
- Division of Endocrinology and Metabolism, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
| |
Collapse
|
12
|
Pyc M, Gidda SK, Seay D, Esnay N, Kretzschmar FK, Cai Y, Doner NM, Greer MS, Hull JJ, Coulon D, Bréhélin C, Yurchenko O, de Vries J, Valerius O, Braus GH, Ischebeck T, Chapman KD, Dyer JM, Mullen RT. LDIP cooperates with SEIPIN and LDAP to facilitate lipid droplet biogenesis in Arabidopsis. THE PLANT CELL 2021; 33:3076-3103. [PMID: 34244767 PMCID: PMC8462815 DOI: 10.1093/plcell/koab179] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 06/26/2021] [Indexed: 05/19/2023]
Abstract
Cytoplasmic lipid droplets (LDs) are evolutionarily conserved organelles that store neutral lipids and play critical roles in plant growth, development, and stress responses. However, the molecular mechanisms underlying their biogenesis at the endoplasmic reticulum (ER) remain obscure. Here we show that a recently identified protein termed LD-associated protein [LDAP]-interacting protein (LDIP) works together with both endoplasmic reticulum-localized SEIPIN and the LD-coat protein LDAP to facilitate LD formation in Arabidopsis thaliana. Heterologous expression in insect cells demonstrated that LDAP is required for the targeting of LDIP to the LD surface, and both proteins are required for the production of normal numbers and sizes of LDs in plant cells. LDIP also interacts with SEIPIN via a conserved hydrophobic helix in SEIPIN and LDIP functions together with SEIPIN to modulate LD numbers and sizes in plants. Further, the co-expression of both proteins is required to restore normal LD production in SEIPIN-deficient yeast cells. These data, combined with the analogous function of LDIP to a mammalian protein called LD Assembly Factor 1, are discussed in the context of a new model for LD biogenesis in plant cells with evolutionary connections to LD biogenesis in other eukaryotes.
Collapse
Affiliation(s)
| | | | - Damien Seay
- U.S. Department of Agriculture, Agricultural Research Service, U.S. Arid-Land Agricultural Research Center, Maricopa, Arizona 85138, USA
| | - Nicolas Esnay
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203, USA
| | - Franziska K. Kretzschmar
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, 37077 Göttingen, Germany
| | | | - Nathan M. Doner
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | | | - J. Joe Hull
- U.S. Department of Agriculture, Agricultural Research Service, U.S. Arid-Land Agricultural Research Center, Maricopa, Arizona 85138, USA
| | - Denis Coulon
- Université de Bordeaux, Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, UMR5200, F-33140 Villenave d’Ornon, France
| | - Claire Bréhélin
- Université de Bordeaux, Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, UMR5200, F-33140 Villenave d’Ornon, France
| | | | - Jan de Vries
- Institute for Microbiology and Genetics, Göttingen Center for Molecular Biosciences and Campus Institute Data Science, Department of Applied Bioinformatics, University of Göttingen, 37077 Göttingen, Germany
| | - Oliver Valerius
- Institute for Microbiology and Genetics and Göttingen Center for Molecular Biosciences, Department for Molecular Microbiology and Genetics, University of Göttingen, 37077 Göttingen, Germany
| | - Gerhard H. Braus
- Institute for Microbiology and Genetics and Göttingen Center for Molecular Biosciences, Department for Molecular Microbiology and Genetics, University of Göttingen, 37077 Göttingen, Germany
| | - Till Ischebeck
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, 37077 Göttingen, Germany
| | - Kent D. Chapman
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203, USA
| | | | | |
Collapse
|
13
|
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.
Collapse
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
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Qiu Y, Ding R, Zhuang Z, Wu J, Yang M, Zhou S, Ye Y, Geng Q, Xu Z, Huang S, Cai G, Wu Z, Yang J. Genome-wide detection of CNV regions and their potential association with growth and fatness traits in Duroc pigs. BMC Genomics 2021; 22:332. [PMID: 33964879 PMCID: PMC8106131 DOI: 10.1186/s12864-021-07654-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 04/27/2021] [Indexed: 11/19/2022] Open
Abstract
Background In the process of pig breeding, the average daily gain (ADG), days to 100 kg (AGE), and backfat thickness (BFT) are directly related to growth rate and fatness. However, the genetic mechanisms involved are not well understood. Copy number variation (CNV), an important source of genetic diversity, can affect a variety of complex traits and diseases and has gradually been thrust into the limelight. In this study, we reported the genome-wide CNVs of Duroc pigs using SNP genotyping data from 6627 animals. We also performed a copy number variation region (CNVR)-based genome-wide association studies (GWAS) for growth and fatness traits in two Duroc populations. Results Our study identified 953 nonredundant CNVRs in U.S. and Canadian Duroc pigs, covering 246.89 Mb (~ 10.90%) of the pig autosomal genome. Of these, 802 CNVRs were in U.S. Duroc pigs with 499 CNVRs were in Canadian Duroc pigs, indicating 348 CNVRs were shared by the two populations. Experimentally, 77.8% of nine randomly selected CNVRs were validated through quantitative PCR (qPCR). We also identified 35 CNVRs with significant association with growth and fatness traits using CNVR-based GWAS. Ten of these CNVRs were associated with both ADG and AGE traits in U.S. Duroc pigs. Notably, four CNVRs showed significant associations with ADG, AGE, and BFT, indicating that these CNVRs may play a pleiotropic role in regulating pig growth and fat deposition. In Canadian Duroc pigs, nine CNVRs were significantly associated with both ADG and AGE traits. Further bioinformatic analysis identified a subset of potential candidate genes, including PDGFA, GPER1, PNPLA2 and BSCL2. Conclusions The present study provides a necessary supplement to the CNV map of the Duroc genome through large-scale population genotyping. In addition, the CNVR-based GWAS results provide a meaningful way to elucidate the genetic mechanisms underlying complex traits. The identified CNVRs can be used as molecular markers for genetic improvement in the molecular-guided breeding of modern commercial pigs. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07654-7.
Collapse
Affiliation(s)
- Yibin Qiu
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, Guangdong, 510642, People's Republic of China
| | - Rongrong Ding
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, Guangdong, 510642, People's Republic of China.,Guangdong Wens Breeding Swine Technology Co., Ltd., Yunfu, Guangdong, 527400, People's Republic of China
| | - Zhanwei Zhuang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, Guangdong, 510642, People's Republic of China
| | - Jie Wu
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, Guangdong, 510642, People's Republic of China
| | - Ming Yang
- Guangdong Wens Breeding Swine Technology Co., Ltd., Yunfu, Guangdong, 527400, People's Republic of China
| | - Shenping Zhou
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, Guangdong, 510642, People's Republic of China
| | - Yong Ye
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, Guangdong, 510642, People's Republic of China
| | - Qian Geng
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, Guangdong, 510642, People's Republic of China
| | - Zheng Xu
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, Guangdong, 510642, People's Republic of China.,Lingnan Guangdong Laboratory of Modern Agriculture, Guangzhou, 510642, People's Republic of China
| | - Sixiu Huang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, Guangdong, 510642, People's Republic of China
| | - Gengyuan Cai
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, Guangdong, 510642, People's Republic of China.,Guangdong Wens Breeding Swine Technology Co., Ltd., Yunfu, Guangdong, 527400, People's Republic of China.,Lingnan Guangdong Laboratory of Modern Agriculture, Guangzhou, 510642, People's Republic of China
| | - Zhenfang Wu
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, Guangdong, 510642, People's Republic of China. .,Guangdong Wens Breeding Swine Technology Co., Ltd., Yunfu, Guangdong, 527400, People's Republic of China. .,Lingnan Guangdong Laboratory of Modern Agriculture, Guangzhou, 510642, People's Republic of China.
| | - Jie Yang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, Guangdong, 510642, People's Republic of China. .,Lingnan Guangdong Laboratory of Modern Agriculture, Guangzhou, 510642, People's Republic of China.
| |
Collapse
|
16
|
Choudhary V, Schneiter R. A Unique Junctional Interface at Contact Sites Between the Endoplasmic Reticulum and Lipid Droplets. Front Cell Dev Biol 2021; 9:650186. [PMID: 33898445 PMCID: PMC8060488 DOI: 10.3389/fcell.2021.650186] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/09/2021] [Indexed: 12/19/2022] Open
Abstract
Lipid droplets (LDs) constitute compartments dedicated to the storage of metabolic energy in the form of neutral lipids. LDs originate from the endoplasmic reticulum (ER) with which they maintain close contact throughout their life cycle. These ER-LD junctions facilitate the exchange of both proteins and lipids between these two compartments. In recent years, proteins that are important for the proper formation of LDs and localize to ER-LD junctions have been identified. This junction is unique as it is generally believed to invoke a transition from the ER bilayer membrane to a lipid monolayer that delineates LDs. Proper formation of this junction requires the ordered assembly of proteins and lipids at specialized ER subdomains. Without such a well-ordered assembly of LD biogenesis factors, neutral lipids are synthesized throughout the ER membrane, resulting in the formation of aberrant LDs. Such ectopically formed LDs impact ER and lipid homeostasis, resulting in different types of lipid storage diseases. In response to starvation, the ER-LD junction recruits factors that tether the vacuole to these junctions to facilitate LD degradation. In addition, LDs maintain close contacts with peroxisomes and mitochondria for metabolic channeling of the released fatty acids toward beta-oxidation. In this review, we discuss the function of different components that ensure proper functioning of LD contact sites, their role in lipogenesis and lipolysis, and their relation to lipid storage diseases.
Collapse
Affiliation(s)
- Vineet Choudhary
- Department of Biotechnology, All India Institute of Medical Sciences (AIIMS), New Delhi, India
| | - Roger Schneiter
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| |
Collapse
|
17
|
Lim K, Haider A, Adams C, Sleigh A, Savage DB. Lipodistrophy: a paradigm for understanding the consequences of "overloading" adipose tissue. Physiol Rev 2020; 101:907-993. [PMID: 33356916 DOI: 10.1152/physrev.00032.2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Lipodystrophies have been recognized since at least the nineteenth century and, despite their rarity, tended to attract considerable medical attention because of the severity and somewhat paradoxical nature of the associated metabolic disease that so closely mimics that of obesity. Within the last 20 yr most of the monogenic subtypes have been characterized, facilitating family genetic screening and earlier disease detection as well as providing important insights into adipocyte biology and the systemic consequences of impaired adipocyte function. Even more recently, compelling genetic studies have suggested that subtle partial lipodystrophy is likely to be a major factor in prevalent insulin-resistant type 2 diabetes mellitus (T2DM), justifying the longstanding interest in these disorders. This progress has also underpinned novel approaches to treatment that, in at least some patients, can be of considerable therapeutic benefit.
Collapse
Affiliation(s)
- Koini Lim
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Afreen Haider
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Claire Adams
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Alison Sleigh
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - David B Savage
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
18
|
New friends for seipin — Implications of seipin partner proteins in the life cycle of lipid droplets. Semin Cell Dev Biol 2020; 108:24-32. [DOI: 10.1016/j.semcdb.2020.04.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 03/20/2020] [Accepted: 04/17/2020] [Indexed: 12/31/2022]
|
19
|
Jia Z, Yue F, Chen X, Narayanan N, Qiu J, Syed SA, Imbalzano AN, Deng M, Yu P, Hu C, Kuang S. Protein Arginine Methyltransferase PRMT5 Regulates Fatty Acid Metabolism and Lipid Droplet Biogenesis in White Adipose Tissues. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2002602. [PMID: 33304767 PMCID: PMC7709973 DOI: 10.1002/advs.202002602] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Indexed: 02/06/2023]
Abstract
The protein arginine methyltransferase 5 (PRMT5) is an emerging regulator of cancer and stem cells including adipogenic progenitors. Here, a new physiological role of PRMT5 in adipocytes and systemic metabolism is reported. Conditional knockout mice were generated to ablate the Prmt5 gene specifically in adipocytes (Prmt5AKO). The Prmt5AKO mice exhibit sex- and depot-dependent progressive lipodystrophy that is more pronounced in females and in visceral (than subcutaneous) white fat. The lipodystrophy and associated energy imbalance, hyperlipidemia, hepatic steatosis, glucose intolerance, and insulin resistance are exacerbated by high-fat-diet. Mechanistically, Prmt5 methylates and releases the transcription elongation factor SPT5 from Berardinelli-Seip congenital lipodystrophy 2 (Bscl2, encoding Seipin) promoter, and Prmt5AKO disrupts Seipin-mediated lipid droplet biogenesis. Prmt5 also methylates Sterol Regulatory Element-Binding Transcription Factor 1a (SREBP1a) and promotes lipogenic gene expression, and Prmt5AKO suppresses SREBP1a-dependent fatty acid metabolic pathways in adipocytes. Thus, PRMT5 plays a critical role in regulating lipid metabolism and lipid droplet biogenesis in adipocytes.
Collapse
Affiliation(s)
- Zhihao Jia
- Department of Animal SciencesPurdue UniversityWest LafayetteIN47907USA
| | - Feng Yue
- Department of Animal SciencesPurdue UniversityWest LafayetteIN47907USA
| | - Xiyue Chen
- Department of Animal SciencesPurdue UniversityWest LafayetteIN47907USA
| | - Naagarajan Narayanan
- Department of Agricultural and Biological EngineeringPurdue UniversityWest LafayetteIN47907USA
- Bindley Bioscience CenterPurdue UniversityWest LafayetteIN47907USA
| | - Jiamin Qiu
- Department of Animal SciencesPurdue UniversityWest LafayetteIN47907USA
| | - Sabriya A. Syed
- Department of Biochemistry and Molecular PharmacologyUniversity of Massachusetts Medical SchoolWorcesterMA01605USA
| | - Anthony N. Imbalzano
- Department of Biochemistry and Molecular PharmacologyUniversity of Massachusetts Medical SchoolWorcesterMA01605USA
| | - Meng Deng
- Department of Agricultural and Biological EngineeringPurdue UniversityWest LafayetteIN47907USA
- Bindley Bioscience CenterPurdue UniversityWest LafayetteIN47907USA
| | - Peng Yu
- West China Biomedical Big Data CenterWest China HospitalSichuan UniversityChengdu610041China
- Medical Big Data CenterSichuan UniversityChengdu610041China
| | - Changdeng Hu
- Department of Medicinal Chemistry and Molecular PharmacologyPurdue UniversityWest LafayetteIndiana47907USA
- Purdue University Center for Cancer ResearchWest LafayetteIndiana47907USA
| | - Shihuan Kuang
- Department of Animal SciencesPurdue UniversityWest LafayetteIN47907USA
- Purdue University Center for Cancer ResearchWest LafayetteIndiana47907USA
| |
Collapse
|
20
|
Bai X, Huang LJ, Chen SW, Nebenfuehr B, Wysolmerski B, Wu JC, Olson SK, Golden A, Wang CW. Loss of the seipin gene perturbs eggshell formation in Caenorhabditis elegans. Development 2020; 147:dev.192997. [PMID: 32820022 DOI: 10.1242/dev.192997] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/11/2020] [Indexed: 12/13/2022]
Abstract
Seipin, an evolutionary conserved protein, plays pivotal roles during lipid droplet (LD) biogenesis and is associated with various human diseases with unclear mechanisms. Here, we analyzed Caenorhabditis elegans mutants deleted of the sole SEIPIN gene, seip-1 Homozygous seip-1 mutants displayed penetrant embryonic lethality, which is caused by the disruption of the lipid-rich permeability barrier, the innermost layer of the C. elegans embryonic eggshell. In C. elegans oocytes and embryos, SEIP-1 is associated with LDs and is crucial for controlling LD size and lipid homeostasis. The seip-1 deletion mutants reduced the ratio of polyunsaturated fatty acids (PUFAs) in their embryonic fatty acid pool. Interestingly, dietary supplementation of selected n-6 PUFAs rescued the embryonic lethality and defective permeability barrier. Accordingly, we propose that SEIP-1 may maternally regulate LD biogenesis and lipid homeostasis to orchestrate the formation of the permeability barrier for eggshell synthesis during embryogenesis. A lipodystrophy allele of seip-1 resulted in embryonic lethality as well and could be rescued by PUFA supplementation. These experiments support a great potential for using C. elegans to model SEIPIN-associated human diseases.
Collapse
Affiliation(s)
- Xiaofei Bai
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Leng-Jie Huang
- Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Sheng-Wen Chen
- Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Benjamin Nebenfuehr
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Brian Wysolmerski
- Department of Biology and Program in Molecular Biology, Pomona College, Claremont, CA 91711, USA
| | - Jui-Ching Wu
- Department of Clinical Laboratory Science and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei 10048, Taiwan
| | - Sara K Olson
- Department of Biology and Program in Molecular Biology, Pomona College, Claremont, CA 91711, USA
| | - Andy Golden
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chao-Wen Wang
- Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan
| |
Collapse
|
21
|
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.
Collapse
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
| |
Collapse
|
22
|
Greer MS, Cai Y, Gidda SK, Esnay N, Kretzschmar FK, Seay D, McClinchie E, Ischebeck T, Mullen RT, Dyer JM, Chapman KD. SEIPIN Isoforms Interact with the Membrane-Tethering Protein VAP27-1 for Lipid Droplet Formation. THE PLANT CELL 2020; 32:2932-2950. [PMID: 32690719 PMCID: PMC7474298 DOI: 10.1105/tpc.19.00771] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 06/08/2020] [Accepted: 07/11/2020] [Indexed: 05/05/2023]
Abstract
SEIPIN proteins are localized to endoplasmic reticulum (ER)-lipid droplet (LD) junctions where they mediate the directional formation of LDs into the cytoplasm in eukaryotic cells. Unlike in animal and yeast cells, which have single SEIPIN genes, plants have three distinct SEIPIN isoforms encoded by separate genes. The mechanism of SEIPIN action remains poorly understood, and here we demonstrate that part of the function of two SEIPIN isoforms in Arabidopsis (Arabidopsis thaliana), AtSEIPIN2 and AtSEIPIN3, may depend on their interaction with the vesicle-associated membrane protein (VAMP)-associated protein (VAP) family member AtVAP27-1. VAPs have well-established roles in the formation of membrane contact sites and lipid transfer between the ER and other organelles, and here, we used a combination of biochemical, cell biology, and genetics approaches to show that AtVAP27-1 interacts with the N termini of AtSEIPIN2 and AtSEIPIN3 and likely supports the normal formation of LDs. This insight indicates that the ER membrane tethering machinery in plant cells could play a role with select SEIPIN isoforms in LD biogenesis at the ER, and additional experimental evidence in Saccharomyces cerevisiae supports the possibility that this interaction may be important in other eukaryotic systems.
Collapse
Affiliation(s)
- Michael Scott Greer
- Department of Biological Sciences, BioDiscovery Institute, University of North Texas, Denton, Texas 76203
| | - Yingqi Cai
- Department of Biological Sciences, BioDiscovery Institute, University of North Texas, Denton, Texas 76203
| | - Satinder K Gidda
- Department of Molecular Cell Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Nicolas Esnay
- Department of Biological Sciences, BioDiscovery Institute, University of North Texas, Denton, Texas 76203
| | - Franziska K Kretzschmar
- Albrecht-von-Haller-Institute for Plant Sciences and Goettingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, University of Goettingen, Justus-von-Liebig Weg 11, 37077 Goettingen, Germany
| | - Damien Seay
- U.S. Department of Agriculture-Agricultural Research Service, U.S. Arid-Land Agricultural Research Center, Maricopa, Arizona 85138
| | - Elizabeth McClinchie
- Department of Biological Sciences, BioDiscovery Institute, University of North Texas, Denton, Texas 76203
| | - Till Ischebeck
- Albrecht-von-Haller-Institute for Plant Sciences and Goettingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, University of Goettingen, Justus-von-Liebig Weg 11, 37077 Goettingen, Germany
| | - Robert T Mullen
- Department of Molecular Cell Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - John M Dyer
- U.S. Department of Agriculture-Agricultural Research Service, U.S. Arid-Land Agricultural Research Center, Maricopa, Arizona 85138
| | - Kent D Chapman
- Department of Biological Sciences, BioDiscovery Institute, University of North Texas, Denton, Texas 76203
| |
Collapse
|
23
|
Ischebeck T, Krawczyk HE, Mullen RT, Dyer JM, Chapman KD. Lipid droplets in plants and algae: Distribution, formation, turnover and function. Semin Cell Dev Biol 2020; 108:82-93. [PMID: 32147380 DOI: 10.1016/j.semcdb.2020.02.014] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 01/28/2020] [Accepted: 02/29/2020] [Indexed: 01/02/2023]
Abstract
Plant oils represent an energy-rich and carbon-dense group of hydrophobic compounds. These oils are not only of economic interest, but also play important, fundamental roles in plant and algal growth and development. The subcellular storage compartments of plant lipids, referred to as lipid droplets (LDs), have long been considered relatively inert oil vessels. However, research in the last decade has revealed that LDs play far more dynamic roles in plant biology than previously appreciated, including transient neutral lipid storage, membrane remodeling, lipid signaling, and stress responses. Here we discuss recent developments in the understanding of LD formation, turnover and function in land plants and algae.
Collapse
Affiliation(s)
- Till Ischebeck
- University of Göttingen, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, 37077, Göttingen, Germany.
| | - Hannah E Krawczyk
- University of Göttingen, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, 37077, Göttingen, Germany
| | - Robert T Mullen
- University of Guelph, Department of Molecular Cell Biology, Guelph, Ontario, N1G 2W1, Canada
| | - John M Dyer
- United States Department of Agriculture, Agriculture Research Service, US Arid-Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Kent D Chapman
- University of North Texas, BioDiscovery Institute, Department of Biological Sciences, Denton, TX, 76203, USA
| |
Collapse
|
24
|
Özen S, Akıncı B, Oral EA. Current Diagnosis, Treatment and Clinical Challenges in the Management of Lipodystrophy Syndromes in Children and Young People. J Clin Res Pediatr Endocrinol 2020; 12:17-28. [PMID: 31434462 PMCID: PMC7127888 DOI: 10.4274/jcrpe.galenos.2019.2019.0124] [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] [Indexed: 12/12/2022] Open
Abstract
Lipodystrophy is a heterogeneous group of disorders characterized by lack of body fat in characteristic patterns, which can be genetic or acquired. Lipodystrophy is associated with insulin resistance that can develop in childhood and adolescence, and usually leads to severe metabolic complications. Diabetes mellitus, hypertriglyceridemia, and hepatic steatosis ordinarily develop in these patients, and most girls suffer from menstrual abnormalities. Severe complications develop at a relatively young age, which include episodes of acute pancreatitis, renal failure, cirrhosis, and complex cardiovascular diseases, and all of these are associated with serious morbidity. Treatment of lipodystrophy consists of medical nutritional therapy, exercise, and the use of anti-hyperglycemic and lipid-lowering agents. New treatment modalities, such as metreleptin replacement, promise much in the treatment of metabolic abnormalities secondary to lipodystrophy. Current challenges in the management of lipodystrophy in children and adolescents include, but are not limited to: (1) establishing specialized centers with experience in providing care for lipodystrophy presenting in childhood and adolescence; (2) optimizing algorithms that can provide some guidance for the use of standard and novel therapies to ensure adequate metabolic control and to prevent complications; (3) educating patients and their parents about lipodystrophy management; (4) improving patient adherence to chronic therapies; (5) reducing barriers to access to novel treatments; and (5) improving the quality of life of these patients and their families.
Collapse
Affiliation(s)
- Samim Özen
- Ege University Faculty of Medicine, Department of Pediatric Endocrinology, İzmir, Turkey,* Address for Correspondence: Ege University Faculty of Medicine, Department of Pediatric Endocrinology, İzmir, Turkey Phone: +90 232 390 12 30 E-mail:
| | - Barış Akıncı
- Dokuz Eylül University Faculty of Medicine, Department of Internal Medicine, Division of Endocrinology and Metabolism, İzmir, Turkey,University of Michigan Medical School, Department of Medicine, and Brehm Center for Diabetes, Division of Metabolism, Endocrinology, and Diabetes, Michigan, USA
| | - Elif A. Oral
- University of Michigan Medical School, Department of Medicine, and Brehm Center for Diabetes, Division of Metabolism, Endocrinology, and Diabetes, Michigan, USA
| |
Collapse
|
25
|
Foss-Freitas MC, Akinci B, Luo Y, Stratton A, Oral EA. Diagnostic strategies and clinical management of lipodystrophy. Expert Rev Endocrinol Metab 2020; 15:95-114. [PMID: 32368944 DOI: 10.1080/17446651.2020.1735360] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/24/2020] [Indexed: 12/16/2022]
Abstract
Introduction: Lipodystrophy is a heterogeneous group of rare diseases characterized by various degrees of fat loss which leads to serious morbidity due to metabolic abnormalities associated with insulin resistance and subtype-specific clinical features associated with underlying molecular etiology.Areas covered: This article aims to help physicians address challenges in diagnosing and managing lipodystrophy. We systematically reviewed the literature on PubMed and Google Scholar databases to summarize the current knowledge in lipodystrophy management.Expert opinion: Adipose tissue is a highly active endocrine organ that regulates metabolic homeostasis in the human body through a comprehensive communication network with other organ systems such as the central nervous system, liver, digestive system, and the immune system. The adipose tissue is capable of producing and secreting numerous factors with important endocrine functions such as leptin that regulates energy homeostasis. Recent developments in the field have helped to solve some of the mysteries behind lipodystrophy that allowed us to get a better understanding of adipocyte function and differentiation. From a clinical standpoint, physicians who suspect lipodystrophy should distinguish the disease from several others that may present with similar clinical features. It is also important for physicians to carefully interpret clinical features, laboratory, and imaging results before moving to more sophisticated tests and making decisions about therapy.
Collapse
Affiliation(s)
- Maria C Foss-Freitas
- Division of Metabolism, Endocrinology and Diabetes (MEND), Department of Internal Medicine, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Ribeirao Preto Medical School, Sao Paulo University, Ribeirao Preto, Brazil
| | - Baris Akinci
- Division of Metabolism, Endocrinology and Diabetes (MEND), Department of Internal Medicine, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Yingying Luo
- Division of Metabolism, Endocrinology and Diabetes (MEND), Department of Internal Medicine, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Beijing, China
| | | | - Elif A Oral
- Division of Metabolism, Endocrinology and Diabetes (MEND), Department of Internal Medicine, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
26
|
Chung J, Wu X, Lambert TJ, Lai ZW, Walther TC, Farese RV. LDAF1 and Seipin Form a Lipid Droplet Assembly Complex. Dev Cell 2019; 51:551-563.e7. [PMID: 31708432 PMCID: PMC7235935 DOI: 10.1016/j.devcel.2019.10.006] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 08/12/2019] [Accepted: 10/08/2019] [Indexed: 10/25/2022]
Abstract
Lipid droplets (LDs) originate from the endoplasmic reticulum (ER) to store triacylglycerol (TG) and cholesterol esters. The ER protein seipin was shown to localize to ER-LD contacts soon after LDs form, but what determines the sites of initial LD biogenesis in the ER is unknown. Here, we identify TMEM159, now re-named lipid droplet assembly factor 1 (LDAF1), as an interaction partner of seipin. Together, LDAF1 and seipin form an ∼600 kDa oligomeric complex that copurifies with TG. LDs form at LDAF1-seipin complexes, and re-localization of LDAF1 to the plasma membrane co-recruits seipin and redirects LD formation to these sites. Once LDs form, LDAF1 dissociates from seipin and moves to the LD surface. In the absence of LDAF1, LDs form only at significantly higher cellular TG concentrations. Our data suggest that the LDAF1-seipin complex is the core protein machinery that facilitates LD biogenesis and determines the sites of their formation in the ER.
Collapse
Affiliation(s)
- Jeeyun Chung
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Xudong Wu
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Talley J Lambert
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Zon Weng Lai
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Harvard Chan Advanced Multi-omics Platform, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Tobias C Walther
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Harvard Chan Advanced Multi-omics Platform, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02124, USA; Howard Hughes Medical Institute, Boston, MA 02115, USA.
| | - Robert V Farese
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02124, USA.
| |
Collapse
|
27
|
Hodson L, Gunn PJ. The regulation of hepatic fatty acid synthesis and partitioning: the effect of nutritional state. Nat Rev Endocrinol 2019; 15:689-700. [PMID: 31554932 DOI: 10.1038/s41574-019-0256-9] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is an increasing global public health burden. NAFLD is strongly associated with type 2 diabetes mellitus, obesity and cardiovascular disease and begins with intrahepatic triacylglycerol accumulation. Under healthy conditions, the liver regulates lipid metabolism to meet systemic energy needs in the fed and fasted states. The processes of fatty acid uptake, fatty acid synthesis and the intracellular partitioning of fatty acids into storage, oxidation and secretion pathways are tightly regulated. When one or more of these processes becomes dysregulated, excess lipid accumulation can occur. Although genetic and environmental factors have been implicated in the development of NAFLD, it remains unclear why an imbalance in these pathways begins. The regulation of fatty acid partitioning occurs at several points, including during triacylglycerol synthesis, lipid droplet formation and lipolysis. These processes are influenced by enzyme function, intake of dietary fats and sugars and whole-body metabolism, and are further affected by the presence of obesity or insulin resistance. Insight into how the liver controls fatty acid metabolism in health and how these processes might be affected in disease would offer the potential for new therapeutic treatments for NAFLD to be developed.
Collapse
Affiliation(s)
- Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Headington, Oxford, UK.
- Oxford NIHR Biomedical Research Centre, Churchill Hospital, Headington, Oxford, UK.
| | - Pippa J Gunn
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Headington, Oxford, UK
- Oxford NIHR Biomedical Research Centre, Churchill Hospital, Headington, Oxford, UK
| |
Collapse
|
28
|
Su WC, Lin YH, Pagac M, Wang CW. Seipin negatively regulates sphingolipid production at the ER-LD contact site. J Cell Biol 2019; 218:3663-3680. [PMID: 31594806 PMCID: PMC6829658 DOI: 10.1083/jcb.201902072] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 06/23/2019] [Accepted: 08/08/2019] [Indexed: 01/06/2023] Open
Abstract
Su et al. show that seipin negatively regulates the production of sphingoid intermediates by binding the enzymes serine palmitoyltransferase and fatty acid elongase at discrete regions of the ER in close vicinity to lipid droplets, thereby mediating the synthesis of two major building blocks for sphingolipids. Seipin is known for its critical role in controlling lipid droplet (LD) assembly at the LD-forming subdomain of the endoplasmic reticulum (ER). Here, we identified a new function of seipin as a negative regulator for sphingolipid production. We show that yeast cells lacking seipin displayed altered sensitivity to sphingolipid inhibitors, accumulated sphingoid precursors and intermediates, and increased serine palmitoyltransferase (SPT) and fatty acid (FA) elongase activities. Seipin associated with SPT and FA elongase, and the interaction was reduced by inhibitors for sphingolipid synthesis in a concentration-dependent manner. We further show that the interactions of seipin with SPT and FA elongase occurred at ER–LD contacts and were likely regulated differentially. Further evidence indicated that LD biogenesis was intact when SPT activity was blocked, whereas excess sphingoid intermediates may affect LD morphology. Expression of human seipin rescued the altered sphingolipids in yeast seipin mutants, suggesting that the negative regulation of sphingolipid synthesis by seipin is likely an evolutionarily conserved process.
Collapse
Affiliation(s)
- Wei-Cheng Su
- Institute of Plant and Microbial Biology, Academia Sinica, Nangang, Taipei, Taiwan
| | - Yi-Hsiu Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Nangang, Taipei, Taiwan
| | - Martin Pagac
- Institute of Plant and Microbial Biology, Academia Sinica, Nangang, Taipei, Taiwan
| | - Chao-Wen Wang
- Institute of Plant and Microbial Biology, Academia Sinica, Nangang, Taipei, Taiwan
| |
Collapse
|
29
|
Fernández-Marmiesse A, Sánchez-Iglesias S, Darling A, O'Callaghan MM, Tonda R, Jou C, Araújo-Vilar D. A de novo heterozygous missense BSCL2 variant in 2 siblings with intractable developmental and epileptic encephalopathy. Seizure 2019; 71:161-165. [DOI: 10.1016/j.seizure.2019.07.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/17/2019] [Accepted: 07/24/2019] [Indexed: 12/11/2022] Open
|
30
|
Oswiecimska J, Dawidziuk M, Gambin T, Ziora K, Marek M, Rzonca S, Guilbride DL, Jhangiani SN, Obuchowicz A, Sikora A, Lupski JR, Wiszniewski W, Gawlinski P. A Patient with Berardinelli-Seip Syndrome, Novel AGPAT2 Splicesite Mutation and Concomitant Development of Non-diabetic Polyneuropathy. J Clin Res Pediatr Endocrinol 2019; 11:319-326. [PMID: 30563316 PMCID: PMC6745459 DOI: 10.4274/jcrpe.galenos.2018.2018.0227] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 12/17/2018] [Indexed: 12/01/2022] Open
Abstract
Primary polyneuropathy in the context of Seip-Berardinelli type 1 seipinopathy, or congenital generalized lipodystrophy type 1 (CGL1) has not been previously reported. We report the case history of a 27 year old female CGL1 patient presenting with an unusual additional development of non-diabetic peripheral neuropathy and learning disabilities in early adolescence. Whole exome sequencing (WES) of the patient genome identified a novel variant, homozygous for a 52 bp intronic deletion in the AGPAT2 locus, coding for 1-acylglycerol-3-phosphate O-acyltransferase 2, which is uniquely associated with CGL1 seipinopathies, with no molecular evidence for dual diagnosis. Functional studies using RNA isolated from patient peripheral blood leucocytes showed abnormal RNA splicing resulting in the loss of 25 amino acids from the patient AGPAT2 protein coding sequence. Stability and transcription levels for the misspliced AGPAT2 mRNA in our patient nonetheless remained normal. Any AGPAT2 protein produced in our patient is therefore likely to be dysfunctional. However, formal linkage of this deletion to the neuropathy observed remains to be shown. The classical clinical presentation of a patient with AGPAT2-associated lipodystrophy shows normal cognition and no development of polyneuropathy. Cognitive disabilities and polyneuropathy are features associated exclusively with clinical CGL type 2 arising from seipin (BSCL2) gene mutations. This case study suggests that in some genetic contexts, AGPAT2 mutations can also produce phenotypes with primary polyneuropathy.
Collapse
Affiliation(s)
- Joanna Oswiecimska
- Medical University of Silesia in Katowice, Department of Pediatrics in Zabrze, Silesia, Poland
| | - Mateusz Dawidziuk
- Institute of Mother and Child, Department of Medical Genetics, Warsaw, Poland
| | - Tomasz Gambin
- Institute of Mother and Child, Department of Medical Genetics, Warsaw, Poland
- Warsaw University of Technology, Institute of Computer Science, Warsaw, Poland
- Baylor College of Medicine, Department of Molecular and Human Genetics, Texas, USA
| | - Katarzyna Ziora
- Medical University of Silesia in Katowice, Department of Pediatrics in Zabrze, Silesia, Poland
| | - Marta Marek
- Medical University of Silesia in Katowice, Department of Pediatrics in Bytom, Silesia, Poland
| | - Sylwia Rzonca
- Institute of Mother and Child, Department of Medical Genetics, Warsaw, Poland
| | | | | | - Anna Obuchowicz
- Medical University of Silesia in Katowice, Department of Pediatrics in Bytom, Silesia, Poland
| | - Alicja Sikora
- Medical University of Silesia in Katowice, Department of Pediatrics in Bytom, Silesia, Poland
| | - James R. Lupski
- Baylor College of Medicine, Department of Molecular and Human Genetics, Texas, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Texas, USA
- Baylor College of Medicine, Department of Pediatrics, Texas, USA
- Texas Children’s Hospital, Texas, USA
| | - Wojciech Wiszniewski
- Institute of Mother and Child, Department of Medical Genetics, Warsaw, Poland
- Oregon Health and Science University, Department of Molecular and Medical Genetics, Portland, USA
| | - Pawel Gawlinski
- Institute of Mother and Child, Department of Medical Genetics, Warsaw, Poland
| |
Collapse
|
31
|
El Zowalaty AE, Li R, Chen W, Ye X. Seipin deficiency leads to increased endoplasmic reticulum stress and apoptosis in mammary gland alveolar epithelial cells during lactation. Biol Reprod 2019; 98:570-578. [PMID: 29236949 DOI: 10.1093/biolre/iox169] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Accepted: 12/10/2017] [Indexed: 02/06/2023] Open
Abstract
Seipin is an integral endoplasmic reticulum (ER) membrane protein encoded by Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2/Bscl2) gene. Most litters (59%) from Bscl2-/- dams mated with wild type (WT) (Bscl2+/+) males did not survive postnatal day 5 (PND5) and pups (Bscl2+/-) lacked milk in their stomachs. The survived litters had reduced pup survival rate at PND21. It was hypothesized that seipin was critical for lactation. Bscl2 was upregulated and highly detected in the lactation day 1 (LD1) WT mammary gland alveolar epithelial cells. LD1 Bscl2-/- mammary glands lacked adipocytes and alveolar clusters and had varied alveolar morphology: from interconnected mammary gland alveoli with dilated lumen and sloughed epithelial cells to undifferentiated mammary gland alveoli with unexpanded lumen. Comparable levels of whey acidic protein (WAP, a major component in rodent milk) staining and Nile Red lipid droplet staining between WT and Bscl2-/- LD1 alveolar epithelial cells indicated normal milk protein synthesis and lipid syntheses in LD1 Bscl2-/- mammary glands. Significantly reduced percentage of larger lipid droplets was detected in LD1 Bscl2-/- alveoli with unexpanded lumen. There was no obviously impaired proliferation detected by PCNA staining but increased apoptosis detected by cleaved caspase-3 staining in LD1 Bscl2-/- alveolar epithelial cells. Increased expression of protein disulfide isomerase and binding immunoglobulin protein in the LD1 Bscl2-/- mammary gland alveolar epithelial cells indicated increased ER stress. This study demonstrates increased ER stress and apoptosis in LD1 Bscl2-/- mammary gland alveolar epithelial cells and reveals a novel in vivo function of seipin in lactation.
Collapse
Affiliation(s)
- Ahmed E El Zowalaty
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA.,Interdisciplinary Toxicology Program, University of Georgia, Athens, Georgia, USA
| | - Rong Li
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA.,Interdisciplinary Toxicology Program, University of Georgia, Athens, Georgia, USA
| | - Weiqin Chen
- Department of Physiology, Augusta University, Augusta, Georgia, USA
| | - Xiaoqin Ye
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA.,Interdisciplinary Toxicology Program, University of Georgia, Athens, Georgia, USA
| |
Collapse
|
32
|
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.
Collapse
|
33
|
Cao Z, Hao Y, Fung CW, Lee YY, Wang P, Li X, Xie K, Lam WJ, Qiu Y, Tang BZ, Shui G, Liu P, Qu J, Kang BH, Mak HY. Dietary fatty acids promote lipid droplet diversity through seipin enrichment in an ER subdomain. Nat Commun 2019; 10:2902. [PMID: 31263173 PMCID: PMC6602954 DOI: 10.1038/s41467-019-10835-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 06/03/2019] [Indexed: 02/06/2023] Open
Abstract
Exogenous metabolites from microbial and dietary origins have profound effects on host metabolism. Here, we report that a sub-population of lipid droplets (LDs), which are conserved organelles for fat storage, is defined by metabolite-modulated targeting of the C. elegans seipin ortholog, SEIP-1. Loss of SEIP-1 function reduces the size of a subset of LDs while over-expression of SEIP-1 has the opposite effect. Ultrastructural analysis reveals SEIP-1 enrichment in an endoplasmic reticulum (ER) subdomain, which co-purifies with LDs. Analyses of C. elegans and bacterial genetic mutants indicate a requirement of polyunsaturated fatty acids (PUFAs) and microbial cyclopropane fatty acids (CFAs) for SEIP-1 enrichment, as confirmed by dietary supplementation experiments. In mammalian cells, heterologously expressed SEIP-1 engages nascent lipid droplets and promotes their subsequent expansion in a conserved manner. Our results suggest that microbial and polyunsaturated fatty acids serve unexpected roles in regulating cellular fat storage by promoting LD diversity. Lipid droplets (LDs) are fat storage organelles that are initiated and expanded by seipins at ER contact sites. Here the authors show that the C. elegans seipin ortholog SEIP-1 is recruited to these sites by certain dietary fatty acids to support the expansion of a subset of LDs.
Collapse
Affiliation(s)
- Zhe Cao
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Yan Hao
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Chun Wing Fung
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Yiu Yiu Lee
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Pengfei Wang
- School of Life Science, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Xuesong Li
- Biophotonics Research Laboratory, Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Kang Xie
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Wen Jiun Lam
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Yifei Qiu
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Ben Zhong Tang
- Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Guanghou Shui
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Pingsheng Liu
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Jianan Qu
- Biophotonics Research Laboratory, Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Byung-Ho Kang
- School of Life Science, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Ho Yi Mak
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China.
| |
Collapse
|
34
|
Celia's encephalopathy and c.974dupG in BSCL2 gene: a hidden change in a known variant. Neurogenetics 2019; 20:73-82. [PMID: 30903322 DOI: 10.1007/s10048-019-00574-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/17/2019] [Indexed: 12/11/2022]
Abstract
Celia's encephalopathy (progressive encephalopathy with/without lipodystrophy (PELD)) is a childhood neurodegenerative disorder with a fatal prognosis before the age of 10, due to the variant c.985C>T in the BSCL2 gene that causes a cryptic splicing site leading to skipping of exon 7. For years, different authors have reported cases of congenital generalized lipodystrophy due to the variant c.974dupG in BSCL2 associated with neurological manifestations of variable severity, although some of them clearly superimposable to PELD. To identify the molecular mechanisms responsible for these neurological alterations in two patients with c.974dupG. Clinical characterization, biochemistry, and neuroimaging studies of two girls carrying this variant. In silico analysis, PCR amplification, and BSCL2 cDNA sequencing. BSCL2-201 transcript expression, which lacks exon 7, by qPCR in fibroblasts from the index case, from a healthy child as a control and from two patients with PELD, and in leukocytes from the index case and her parents. One with a severe encephalopathy including a picture of intellectual deficiency, severe language impairment, myoclonic epilepsy, and lipodystrophy as described in PELD, dying at 9 years and 9 months of age. The other 2-year-old patient showed incipient signs of neurological involvement. In silico and cDNA sequencing studies showed that variant c.974dupG gives rise to skipping of exon 7. The expression of BSCL2-201 in fibroblasts was significantly higher in the index case than in the healthy child, although less than in the case with homozygous PELD due to c.985C>T variant. The expression of this transcript was approximately half in the healthy carrier parents of this patient. The c.974dupG variant leads to the skipping of exon 7 of the BSCL2 gene and is responsible for a variant of Celia's encephalopathy, with variable phenotypic expression.
Collapse
|
35
|
Qin YY, Zhang X, Xiang LQ, Shan QW, Li SD, Yan J, Lin FQ. A New Compound Heterozygous Mutation Of BSCL2 In A Chinese Zhuang Ethnic Family With Congenital Generalized Lipodystrophy. Diabetes Metab Syndr Obes 2019; 12:2583-2587. [PMID: 31824185 PMCID: PMC6901035 DOI: 10.2147/dmso.s207293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 10/14/2019] [Indexed: 12/28/2022] Open
Abstract
PURPOSE This study aims to report the clinical features of an infant with CGL in a Chinese Zhuang ethnic family, whose family members were discovered to carry new pathogenic mutations in the BSCL2. PATIENTS AND METHODS In this study, we report clinical and molecular investigations of CGL disease in a family of 4 members (parents and two sons). We used whole exome sequencing (WES) in the family to examine the genetic cause of the disease. RESULTS The proband presented with skin pigmentation, hypertriglyceridemia and diabetes. WES identified a previously unreported compound heterozygous mutation in the BSCL2 (c.545_546insCCG heterozygous mutation and exon 3 heterozygous deletion) in the proband. His mother is a heterozygous carrier of the c.545_546insCCG mutation and his father and brother are carriers of the exon 3 heterozygous deletion. CONCLUSION Compound heterozygous mutation of the BSCL2 (new c.545_546insCCG heterozygous mutation and new exon 3 heterozygous deletion) was detected in the proband with characteristic clinical manifestations of CGL2.
Collapse
Affiliation(s)
- Yuan-yuan Qin
- Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People’s Republic of China
| | - Xuan Zhang
- Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People’s Republic of China
| | - Li-qun Xiang
- Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People’s Republic of China
| | - Qing-wen Shan
- Department of Pediatric, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People’s Republic of China
| | - Shou-dong Li
- Guangxi Anren Xin Bio Technology Co., Ltd, Nanning, Guangxi Zhuang Autonomous Region, People’s Republic of China
| | - Jie Yan
- Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People’s Republic of China
| | - Fa-quan Lin
- Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People’s Republic of China
- Correspondence: Fa-quan Lin The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People’s Republic of ChinaTel +86-771-5329287 Email
| |
Collapse
|
36
|
Sánchez-Iglesias S, Fernández-Liste A, Guillín-Amarelle C, Rábano A, Rodriguez-Cañete L, González-Méndez B, Fernández-Pombo A, Senra A, Araújo-Vilar D. Does Seipin Play a Role in Oxidative Stress Protection and Peroxisome Biogenesis? New Insights from Human Brain Autopsies. Neuroscience 2018; 396:119-137. [PMID: 30447390 DOI: 10.1016/j.neuroscience.2018.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 11/02/2018] [Accepted: 11/03/2018] [Indexed: 12/19/2022]
Abstract
Seipin is a widely expressed protein but with highest levels found in the brain and testes. Seipin function is not yet completely understood, therefore the aim of this study was to evaluate the expression of BSCL2 transcripts in the central nervous system (CNS) of humans and investigate the effect of their overexpression on a neuron model and their relationship with oxidative stress protection, as well as shed light on the pathogenic mechanisms of Celia's Encephalopathy. We analyzed the expression of BSCL2 transcripts using real-time RT-PCR in samples across the brain regions of subjects who underwent necropsy and from a case with Celia's Encephalopathy. The transcript encoding the long seipin isoform (BSCL2-203, 462 aa) is expressed primarily in the brain and its expression is inversely correlated with age in the temporal lobe, amygdala, and hypothalamus. Strong positive correlations were found between BSCL2 expression and some genes encoding protective enzymes against oxidative stress including SOD1 and SOD2, as well as peroxisome proliferator-activated receptor gamma (PPARG) in the amygdala. These results were experimentally corroborated by overexpressing BSCL2 transcripts in SH-SY5Y cells with lentiviral transduction and assessing their effects on neuron differentiated cells. Confocal microscopy studies showed that both seipin and PEX16 are closely expressed in the hypothalami of healthy human brains, and PEX16 was absent in the same region of the PELD case. We hypothesize that seipin has specific CNS functions and may play a role in peroxisome biogenesis.
Collapse
Affiliation(s)
- Sofía Sánchez-Iglesias
- Thyroid and Metabolic Diseases Unit (U.E.T.eM.), Department of Psychiatry, Radiology, Public Health, Nursing and Medicine (Medicine Area), Center for Research in Molecular Medicine and Chronic Diseases (CIMUS)-IDIS, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Alberto Fernández-Liste
- Instituto de Medicina Legal de Galicia (IMELGA), 15707 Santiago de Compostela, A Coruña, Spain
| | - Cristina Guillín-Amarelle
- Thyroid and Metabolic Diseases Unit (U.E.T.eM.), Department of Psychiatry, Radiology, Public Health, Nursing and Medicine (Medicine Area), Center for Research in Molecular Medicine and Chronic Diseases (CIMUS)-IDIS, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Alberto Rábano
- Neuropathology Department and Tissue Bank, Fundación CIEN, 28031 Madrid, Spain
| | - Leticia Rodriguez-Cañete
- Thyroid and Metabolic Diseases Unit (U.E.T.eM.), Department of Psychiatry, Radiology, Public Health, Nursing and Medicine (Medicine Area), Center for Research in Molecular Medicine and Chronic Diseases (CIMUS)-IDIS, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Blanca González-Méndez
- Thyroid and Metabolic Diseases Unit (U.E.T.eM.), Department of Psychiatry, Radiology, Public Health, Nursing and Medicine (Medicine Area), Center for Research in Molecular Medicine and Chronic Diseases (CIMUS)-IDIS, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Antía Fernández-Pombo
- Thyroid and Metabolic Diseases Unit (U.E.T.eM.), Department of Psychiatry, Radiology, Public Health, Nursing and Medicine (Medicine Area), Center for Research in Molecular Medicine and Chronic Diseases (CIMUS)-IDIS, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Ana Senra
- Department of Physiology, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS)-IDIS, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - David Araújo-Vilar
- Thyroid and Metabolic Diseases Unit (U.E.T.eM.), Department of Psychiatry, Radiology, Public Health, Nursing and Medicine (Medicine Area), Center for Research in Molecular Medicine and Chronic Diseases (CIMUS)-IDIS, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
| |
Collapse
|
37
|
Akinci B, Meral R, Oral EA. Phenotypic and Genetic Characteristics of Lipodystrophy: Pathophysiology, Metabolic Abnormalities, and Comorbidities. Curr Diab Rep 2018; 18:143. [PMID: 30406415 DOI: 10.1007/s11892-018-1099-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW This article focuses on recent progress in understanding the genetics of lipodystrophy syndromes, the pathophysiology of severe metabolic abnormalities caused by these syndromes, and causes of severe morbidity and a possible signal of increased mortality associated with lipodystrophy. An updated classification scheme is also presented. RECENT FINDINGS Lipodystrophy encompasses a group of heterogeneous rare diseases characterized by generalized or partial lack of adipose tissue and associated metabolic abnormalities including altered lipid metabolism and insulin resistance. Recent advances in the field have led to the discovery of new genes associated with lipodystrophy and have also improved our understanding of adipose biology, including differentiation, lipid droplet assembly, and metabolism. Several registries have documented the natural history of the disease and the serious comorbidities that patients with lipodystrophy face. There is also evolving evidence for increased mortality rates associated with lipodystrophy. Lipodystrophy syndromes represent a challenging cluster of diseases that lead to severe insulin resistance, a myriad of metabolic abnormalities, and serious morbidity. The understanding of these syndromes is evolving in parallel with the identification of novel disease-causing mechanisms.
Collapse
Affiliation(s)
- Baris Akinci
- Brehm Center for Diabetes Research, Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, 1000 Wall Street, Room 5313, Ann Arbor, MI, 48105, USA
- Division of Endocrinology, Department of Internal Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Rasimcan Meral
- Brehm Center for Diabetes Research, Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, 1000 Wall Street, Room 5313, Ann Arbor, MI, 48105, USA
| | - Elif Arioglu Oral
- Brehm Center for Diabetes Research, Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, 1000 Wall Street, Room 5313, Ann Arbor, MI, 48105, USA.
| |
Collapse
|
38
|
Lugat A, Joubert M, Cariou B, Prieur X. [At the heart of diabetic cardiomyopathy: Bscl2 knockout mice to investigate glucotoxicity]. Med Sci (Paris) 2018; 34:563-570. [PMID: 30067203 DOI: 10.1051/medsci/20183406016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a well-recognized independent risk factor for heart failure (HF). T2DM is associated with altered cardiac energy metabolism, leading to ectopic lipid accumulation and glucose overload. However, the relative contribution of these two parameters remains unclear. In order to get new insight into the mechanism involved in diabetic cardiomyopathy, the cardiac phenotype of a unique T2DM mice model has been performed: the seipin knockout mice (SKO). Cardiac phenotyping revealed a diastolic dysfunction associated with hyperglycemia in these mice with a chronic activation of the hexosamine biosynthetic pathway (HBP), suggesting a glucose overload. An inhibitor of the renal sodium/glucose cotransporter 2 (SGLT2), dapagliflozin, successfully prevented the development of cardiomyopathy in SKO mice. This is particularly relevant, given that SGLT2i treatment reduces cardiovascular event in T2DM patients. Therefore, glucose lowering appears an important therapeutic target to prevent cardiac dysfunction associated with T2DM.
Collapse
Affiliation(s)
- Alexandre Lugat
- Institut du thorax, Inserm, CNRS, univ Nantes, CHU Nantes, 8, quai Moncousu, Nantes, F-44000, France
| | - Michael Joubert
- Service Endocrinologie, CHU de Caen, Caen, F-14003, France - EA4650 - Unicaen - GIP Cyceron - Caen, Caen, F-14074, France
| | - Bertrand Cariou
- Institut du thorax, Inserm, CNRS, univ Nantes, CHU Nantes, 8, quai Moncousu, Nantes, F-44000, France
| | - Xavier Prieur
- Institut du thorax, Inserm, CNRS, univ Nantes, Nantes, F-44000, France
| |
Collapse
|
39
|
Ding L, Yang X, Tian H, Liang J, Zhang F, Wang G, Wang Y, Ding M, Shui G, Huang X. Seipin regulates lipid homeostasis by ensuring calcium-dependent mitochondrial metabolism. EMBO J 2018; 37:embj.201797572. [PMID: 30049710 DOI: 10.15252/embj.201797572] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 07/05/2018] [Accepted: 07/09/2018] [Indexed: 02/06/2023] Open
Abstract
Seipin, the gene that causes Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2), is important for adipocyte differentiation and lipid homeostasis. Previous studies in Drosophila revealed that Seipin promotes ER calcium homeostasis through the Ca2+-ATPase SERCA, but little is known about the events downstream of perturbed ER calcium homeostasis that lead to decreased lipid storage in Drosophila dSeipin mutants. Here, we show that glycolytic metabolites accumulate and the downstream mitochondrial TCA cycle is impaired in dSeipin mutants. The impaired TCA cycle further leads to a decreased level of citrate, a critical component of lipogenesis. Mechanistically, Seipin/SERCA-mediated ER calcium homeostasis is important for maintaining mitochondrial calcium homeostasis. Reduced mitochondrial calcium in dSeipin mutants affects the TCA cycle and mitochondrial function. The lipid storage defects in dSeipin mutant fat cells can be rescued by replenishing mitochondrial calcium or by restoring the level of citrate through genetic manipulations or supplementation with exogenous metabolites. Together, our results reveal that Seipin promotes adipose tissue lipid storage via calcium-dependent mitochondrial metabolism.
Collapse
Affiliation(s)
- Long Ding
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Xiao Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - He Tian
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Jingjing Liang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Fengxia Zhang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Guodong Wang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Yingchun Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Mei Ding
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Guanghou Shui
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Xun Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China .,University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
40
|
Henne WM, Reese ML, Goodman JM. The assembly of lipid droplets and their roles in challenged cells. EMBO J 2018; 37:embj.201898947. [PMID: 29789390 DOI: 10.15252/embj.201898947] [Citation(s) in RCA: 167] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 03/08/2018] [Accepted: 03/22/2018] [Indexed: 12/14/2022] Open
Abstract
Cytoplasmic lipid droplets are important organelles in nearly every eukaryotic and some prokaryotic cells. Storing and providing energy is their main function, but they do not work in isolation. They respond to stimuli initiated either on the cell surface or in the cytoplasm as conditions change. Cellular stresses such as starvation and invasion are internal insults that evoke changes in droplet metabolism and dynamics. This review will first outline lipid droplet assembly and then discuss how droplets respond to stress and in particular nutrient starvation. Finally, the role of droplets in viral and microbial invasion will be presented, where an unresolved issue is whether changes in droplet abundance promote the invader, defend the host, to try to do both. The challenges of stress and infection are often accompanied by changes in physical contacts between droplets and other organelles. How these changes may result in improving cellular physiology, an ongoing focus in the field, is discussed.
Collapse
Affiliation(s)
- W Mike Henne
- Department of Cell Biology, University of Texas Southwestern Medical School, Dallas, TX, USA
| | - Michael L Reese
- Department of Pharmacology, University of Texas Southwestern Medical School, Dallas, TX, USA
| | - Joel M Goodman
- Department of Pharmacology, University of Texas Southwestern Medical School, Dallas, TX, USA
| |
Collapse
|
41
|
Xu D, Li Y, Wu L, Li Y, Zhao D, Yu J, Huang T, Ferguson C, Parton RG, Yang H, Li P. Rab18 promotes lipid droplet (LD) growth by tethering the ER to LDs through SNARE and NRZ interactions. J Cell Biol 2018; 217:975-995. [PMID: 29367353 PMCID: PMC5839781 DOI: 10.1083/jcb.201704184] [Citation(s) in RCA: 146] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 10/12/2017] [Accepted: 12/22/2017] [Indexed: 12/16/2022] Open
Abstract
Lipid incorporation from endoplasmic reticulum (ER) to lipid droplet (LD) is important in controlling LD growth and intracellular lipid homeostasis. However, the molecular link mediating ER and LD cross talk remains elusive. Here, we identified Rab18 as an important Rab guanosine triphosphatase in controlling LD growth and maturation. Rab18 deficiency resulted in a drastically reduced number of mature LDs and decreased lipid storage, and was accompanied by increased ER stress. Rab3GAP1/2, the GEF of Rab18, promoted LD growth by activating and targeting Rab18 to LDs. LD-associated Rab18 bound specifically to the ER-associated NAG-RINT1-ZW10 (NRZ) tethering complex and their associated SNAREs (Syntaxin18, Use1, BNIP1), resulting in the recruitment of ER to LD and the formation of direct ER-LD contact. Cells with defects in the NRZ/SNARE complex function showed reduced LD growth and lipid storage. Overall, our data reveal that the Rab18-NRZ-SNARE complex is critical protein machinery for tethering ER-LD and establishing ER-LD contact to promote LD growth.
Collapse
Affiliation(s)
- Dijin Xu
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yuqi Li
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Lizhen Wu
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Ying Li
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Dongyu Zhao
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jinhai Yu
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Tuozhi Huang
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Charles Ferguson
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia.,Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Australia
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Peng Li
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| |
Collapse
|
42
|
Ponte CMM, Fernandes VO, Gurgel MHC, Vasconcelos ITGF, Karbage LBDAS, Liberato CBR, Negrato CA, Gomes MDB, Montenegro APDR, Montenegro Júnior RM. Early commitment of cardiovascular autonomic modulation in Brazilian patients with congenital generalized lipodystrophy. BMC Cardiovasc Disord 2018; 18:6. [PMID: 29329523 PMCID: PMC5767058 DOI: 10.1186/s12872-017-0738-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 12/13/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Metabolic abnormalities in congenital generalized lipodystrophy (CGL) are associated with microvascular complications. However, the evaluation of different types of neuropathy in these patients, including the commitment of cardiovascular autonomic modulation, is scarce. The objective of the present study was to determine the prevalence of cardiovascular autonomic neuropathy (CAN) in patients with CGL compared with individuals with type 1 diabetes and healthy subjects. METHODS Ten patients with CGL, 20 patients with type 1 diabetes and 20 healthy subjects were included in the study. Controls were paired 1:2 for age, gender, BMI and pubertal stage. Heart rate variability (HRV) was analyzed using cardiovascular autonomic reflex tests, including postural hypotension test, Valsalva (VAL), respiratory (E/I) and orthostatic (30/15) coefficients, and spectral analysis of the HRV, determining very low (VLF), low (LF) and high (HF) frequencies components. The diagnosis of CAN was defined as the presence of at least two altered tests. RESULTS CAN was detected in 40% of the CGL patients, 5% in type 1 diabetes patients and was absent in healthy individuals (p < 0.05). We observed a significant reduction in the E/I, VLF, LF and HF in CGL cases vs. type 1 diabetes and healthy individuals and lower levels of 30/15 and VAL in CGL vs. healthy individuals. A significant positive correlation was observed between leptin and 30/15 coefficient (r = 0.396; p = 0.036) after adjusting for insulin resistance and triglycerides. Autonomic cardiovascular tests were associated with HbA1c, HOMA-IR, triglycerides and albumin/creatinine ratio in CGL cases. CONCLUSIONS We observed a high prevalence of CAN in young patients with CGL, suggesting that insulin resistance, hypertriglyceridemia and hypoleptinemia, may have been involved in early CAN development. Additional studies are needed to evaluate the role of leptinemia in the physiopathogenesis of the condition.
Collapse
|
43
|
|
44
|
Eisenberg-Bord M, Mari M, Weill U, Rosenfeld-Gur E, Moldavski O, Castro IG, Soni KG, Harpaz N, Levine TP, Futerman AH, Reggiori F, Bankaitis VA, Schuldiner M, Bohnert M. Identification of seipin-linked factors that act as determinants of a lipid droplet subpopulation. J Cell Biol 2017; 217:269-282. [PMID: 29187527 PMCID: PMC5748981 DOI: 10.1083/jcb.201704122] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 09/21/2017] [Accepted: 10/23/2017] [Indexed: 02/07/2023] Open
Abstract
Eisenberg-Bord et al. describe a lipid droplet (LD) subpopulation with a unique proteome, which is adjacent to the nucleus–vacuole junction contact site. They identify the LD machinery, which cooperates with the lipodystrophy factor seipin as a key determinant of LD identity and suggest a mechanism for functional organelle diversification. Functional heterogeneity within the lipid droplet (LD) pool of a single cell has been observed, yet the underlying mechanisms remain enigmatic. Here, we report on identification of a specialized LD subpopulation characterized by a unique proteome and a defined geographical location at the nucleus–vacuole junction contact site. In search for factors determining identity of these LDs, we screened ∼6,000 yeast mutants for loss of targeting of the subpopulation marker Pdr16 and identified Ldo45 (LD organization protein of 45 kD) as a crucial targeting determinant. Ldo45 is the product of a splicing event connecting two adjacent genes (YMR147W and YMR148W/OSW5/LDO16). We show that Ldo proteins cooperate with the LD biogenesis component seipin and establish LD identity by defining positioning and surface-protein composition. Our studies suggest a mechanism to establish functional differentiation of organelles, opening the door to better understanding of metabolic decisions in cells.
Collapse
Affiliation(s)
| | - Muriel Mari
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Uri Weill
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Eden Rosenfeld-Gur
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Ofer Moldavski
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Inês G Castro
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Krishnakant G Soni
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX
| | - Nofar Harpaz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Tim P Levine
- UCL Institute of Ophthalmology, London, England, UK
| | - Anthony H Futerman
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Fulvio Reggiori
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Vytas A Bankaitis
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Maria Bohnert
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| |
Collapse
|
45
|
余 淦, 欧 正, 陶 启, 万 国, 陆 宗, 郎 斌. [Role of lncRNA PTENP1 in tumorigenesis and progression of bladder cancer and the molecular mechanism]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2017; 37:1494-1500. [PMID: 29180330 PMCID: PMC6779653 DOI: 10.3969/j.issn.1673-4254.2017.11.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Indexed: 06/07/2023]
Abstract
OBJECTIVE To explore the molecular mechanism underlying the biological function of lncRNA PTENP1 in bladder cancer. METHODS Expressions of PTENP1, PTEN and miR-17 were examined by quantitative reverse transcriptase PCR (qRT-PCR) in 12 bladder cancer tissues. The expression of PTEN was examined by Western blotting in bladder cancer cell lines T24 and 5637 overexpressing PTENP1. Luciferase reporter assay was performed to confirm the targeting of miR-17 to PTENP1 and PTEN. T24 and 5637 cell lines with stable overexpression of PTENP1 and mir-17 were used to investigate effect of PTNE and miR-17 on the function of PTENP1 in bladder cancer. RESULTS The expression of miR-17 was up-regulated and PTENP1 and PTEN were down-regulated in bladder cancer tissues, where a positive correlation was found between PTENP1 and PTEN expressions and a negative correlation between PTENP1 and miR-17 (P<0.05). Overexpression of PTENP1 in bladder cancer cell lines T24 and 5637 obviously enhanced the expression of PTEN protein. miR-17 was found to target both PTENP1 and PTEN and promote the growth of bladder cancer. miR-17 could partially restore the tumor-suppressing activity of PTENP1 in bladder cancer. CONCLUSION By binding with miR-17, lncRNA PTENP1 functions as a PTEN competing endogenous RNA (ceRNA) to suppress the progression of bladder cancer.
Collapse
Affiliation(s)
- 淦 余
- 华中科技大学同济医学院附属同济医院泌尿外科,湖北 武汉 430030Department of Urology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - 正岳 欧
- 澳门理工学院高等卫生学校,澳门 999078School of Health Sciences, Macao Polytechnic Institute, Macao 999078, China
| | - 启业 陶
- 澳门理工学院高等卫生学校,澳门 999078School of Health Sciences, Macao Polytechnic Institute, Macao 999078, China
| | - 国悦 万
- 澳门理工学院高等卫生学校,澳门 999078School of Health Sciences, Macao Polytechnic Institute, Macao 999078, China
| | - 宗浩 陆
- 澳门理工学院高等卫生学校,澳门 999078School of Health Sciences, Macao Polytechnic Institute, Macao 999078, China
| | - 斌 郎
- 澳门理工学院高等卫生学校,澳门 999078School of Health Sciences, Macao Polytechnic Institute, Macao 999078, China
| |
Collapse
|
46
|
Pagac M, Cooper DE, Qi Y, Lukmantara IE, Mak HY, Wu Z, Tian Y, Liu Z, Lei M, Du X, Ferguson C, Kotevski D, Sadowski P, Chen W, Boroda S, Harris TE, Liu G, Parton RG, Huang X, Coleman RA, Yang H. SEIPIN Regulates Lipid Droplet Expansion and Adipocyte Development by Modulating the Activity of Glycerol-3-phosphate Acyltransferase. Cell Rep 2017; 17:1546-1559. [PMID: 27806294 PMCID: PMC5647143 DOI: 10.1016/j.celrep.2016.10.037] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 09/03/2016] [Accepted: 10/10/2016] [Indexed: 12/26/2022] Open
Abstract
Berardinelli-Seip congenital lipodystrophy 2 (BSCL2) is caused by loss-of-function mutations in SEIPIN, a protein implicated in both adipogenesis and lipid droplet expansion but whose molecular function remains obscure. Here, we identify physical and functional interactions between SEIPIN and microsomal isoforms of glycerol-3-phosphate acyltransferase (GPAT) in multiple organisms. Compared to controls, GPAT activity was elevated in SEIPIN-deficient cells and tissues and GPAT kinetic values were altered. Increased GPAT activity appears to underpin the block in adipogenesis and abnormal lipid droplet morphology associated with SEIPIN loss. Overexpression of Gpat3 blocked adipogenesis, and Gpat3 knockdown in SEIPIN-deficient preadipocytes partially restored differentiation. GPAT overexpression in yeast, preadipocytes, and fly salivary glands also formed supersized lipid droplets. Finally, pharmacological inhibition of GPAT in Seipin-/- mouse preadipocytes partially restored adipogenesis. These data identify SEIPIN as an evolutionarily conserved regulator of microsomal GPAT and suggest that GPAT inhibitors might be useful for the treatment of human BSCL2 patients.
Collapse
Affiliation(s)
- Martin Pagac
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Daniel E Cooper
- Department of Nutrition, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Yanfei Qi
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Ivan E Lukmantara
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Hoi Yin Mak
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Zengying Wu
- Department of Nutrition, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Yuan Tian
- State Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhonghua Liu
- State Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Mona Lei
- 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
| | - Charles Ferguson
- Institute for Molecular Bioscience, The University of Queensland, Queensland, QLD 4072, Australia
| | - Damian Kotevski
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Pawel Sadowski
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Weiqin Chen
- Department of Physiology, Medical College of Georgia Regents University, Augusta, GA 30912, USA
| | - Salome Boroda
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Thurl E Harris
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - George Liu
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing 100191, China
| | - Robert G Parton
- Institute for Molecular Bioscience, The University of Queensland, Queensland, QLD 4072, Australia
| | - Xun Huang
- State Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Rosalind A Coleman
- Department of Nutrition, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
| |
Collapse
|
47
|
Chen X, Goodman JM. The collaborative work of droplet assembly. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1205-1211. [PMID: 28711458 DOI: 10.1016/j.bbalip.2017.07.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 07/05/2017] [Accepted: 07/06/2017] [Indexed: 10/19/2022]
Abstract
Three proteins have been implicated in the assembly of cytoplasmic lipid droplets: seipin, FIT2, and perilipin. This review examines the current theories of seipin function as well as the evidence for the involvement of all three proteins in droplet biogenesis, and ends with a proposal of how they collaborate to regulate the formation of droplets. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink.
Collapse
Affiliation(s)
- Xiao Chen
- Department of Pharmacology, University of Texas Southwestern Medical School, Dallas, TX 75390-9041, United States
| | - Joel M Goodman
- Department of Pharmacology, University of Texas Southwestern Medical School, Dallas, TX 75390-9041, United States.
| |
Collapse
|
48
|
Jackson CL, Walch L, Verbavatz JM. Lipids and Their Trafficking: An Integral Part of Cellular Organization. Dev Cell 2017; 39:139-153. [PMID: 27780039 DOI: 10.1016/j.devcel.2016.09.030] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
An evolutionarily conserved feature of cellular organelles is the distinct phospholipid composition of their bounding membranes, which is essential to their identity and function. Within eukaryotic cells, two major lipid territories can be discerned, one centered on the endoplasmic reticulum and characterized by membranes with lipid packing defects, the other comprising plasma-membrane-derived organelles and characterized by membrane charge. We discuss how this cellular lipid organization is maintained, how lipid flux is regulated, and how perturbations in cellular lipid homeostasis can lead to disease.
Collapse
Affiliation(s)
- Catherine L Jackson
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris, France.
| | - Laurence Walch
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris, France
| | - Jean-Marc Verbavatz
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris, France
| |
Collapse
|
49
|
Akinci G, Topaloglu H, Demir T, Danyeli AE, Talim B, Keskin FE, Kadioglu P, Talip E, Altay C, Yaylali GF, Bilen H, Nur B, Demir L, Onay H, Akinci B. Clinical spectra of neuromuscular manifestations in patients with lipodystrophy: A multicenter study. Neuromuscul Disord 2017; 27:923-930. [PMID: 28754454 DOI: 10.1016/j.nmd.2017.05.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 05/23/2017] [Accepted: 05/25/2017] [Indexed: 01/14/2023]
Abstract
Lipodystrophy is a heterogeneous group of disorders characterized by loss of adipose tissue. Here, we report on clinical spectra of neuromuscular manifestations of Turkish patients with lipodystrophy. Seventy-four patients with lipodystrophy and 20 healthy controls were included. Peripheral sensorimotor neuropathy was a common finding (67.4%) in lipodystrophic patients with diabetes. Neuropathic foot ulcers were observed in 4 patients. Drop foot developed in 1 patient with congenital generalized lipodystrophy type 1. Muscle symptoms and hypertrophy were consistent findings in congenital generalized lipodystrophy (21/21) and familial partial lipodystrophy (25/34); on the other hand, overt myopathy with elevated creatine kinase activity was a distinctive characteristic of congenital generalized lipodystrophy type 4. Muscle biopsies revealed myopathic changes at different levels. Accumulation of triglycerides was observed which contributes to insulin resistance. All patients with congenital generalized lipodystrophy suffered from tight Achilles tendons at various levels. Scoliosis was observed in congenital generalized lipodystrophy type 4 (2/2) and familial partial lipodystrophy type 2 (2/17). Atlantoaxial instability was unique to congenital generalized lipodystrophy type 4 (2/2). Bone cysts were detected in congenital generalized lipodystrophy type 1 (7/10) and congenital generalized lipodystrophy type 2 (2/8). Our study suggests that lipodystrophies are associated with a wide spectrum of neuromuscular abnormalities.
Collapse
Affiliation(s)
- Gulcin Akinci
- Department of Pediatric Neurology, Dr. Behcet Uz Children's Hospital, Izmir, Turkey.
| | - Haluk Topaloglu
- Department of Pediatric Neurology, Hacettepe University Children's Hospital, Ankara, Turkey
| | - Tevfik Demir
- Department of Internal Medicine, Division of Endocrinology, Dokuz Eylul University, Izmir, Turkey
| | | | - Beril Talim
- Pediatric Pathology Unit, Hacettepe University Children's Hospital, Ankara, Turkey
| | - Fatma Ela Keskin
- Department of Internal Medicine, Division of Endocrinology, Gaziosmanpasa Taksim Training Hospital, Istanbul, Turkey
| | - Pinar Kadioglu
- Department of Internal Medicine, Division of Endocrinology, Istanbul University, Istanbul, Turkey
| | - Enez Talip
- Department of Internal Medicine, Division of Endocrinology, Dokuz Eylul University, Izmir, Turkey
| | - Canan Altay
- Department of Radiology, Dokuz Eylul University, Izmir, Turkey
| | - Guzin Fidan Yaylali
- Department of Internal Medicine, Division of Endocrinology, Pamukkale University, Denizli, Turkey
| | - Habib Bilen
- Department of Internal Medicine, Division of Endocrinology, Ataturk University, Erzurum, Turkey
| | - Banu Nur
- Department of Pediatrics, Division of Pediatric Genetics, Akdeniz University, Antalya, Turkey
| | - Leyla Demir
- Department of Biochemistry, Ataturk Training Hospital, Izmir, Turkey
| | - Huseyin Onay
- Department of Medical Genetics, Ege University, Izmir, Turkey
| | - Baris Akinci
- Department of Internal Medicine, Division of Endocrinology, Dokuz Eylul University, Izmir, Turkey
| |
Collapse
|
50
|
Haidar M, Timmerman V. Autophagy as an Emerging Common Pathomechanism in Inherited Peripheral Neuropathies. Front Mol Neurosci 2017; 10:143. [PMID: 28553203 PMCID: PMC5425483 DOI: 10.3389/fnmol.2017.00143] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 04/26/2017] [Indexed: 12/16/2022] Open
Abstract
The inherited peripheral neuropathies (IPNs) comprise a growing list of genetically heterogeneous diseases. With mutations in more than 80 genes being reported to cause IPNs, a wide spectrum of functional consequences is expected to follow this genotypic diversity. Hence, the search for a common pathomechanism among the different phenotypes has become the holy grail of functional research into IPNs. During the last decade, studies on several affected genes have shown a direct and/or indirect correlation with autophagy. Autophagy, a cellular homeostatic process, is required for the removal of cell aggregates, long-lived proteins and dead organelles from the cell in double-membraned vesicles destined for the lysosomes. As an evolutionarily highly conserved process, autophagy is essential for the survival and proper functioning of the cell. Recently, neuronal cells have been shown to be particularly vulnerable to disruption of the autophagic pathway. Furthermore, autophagy has been shown to be affected in various common neurodegenerative diseases of both the central and the peripheral nervous system including Alzheimer's, Parkinson's, and Huntington's diseases. In this review we provide an overview of the genes involved in hereditary neuropathies which are linked to autophagy and we propose the disruption of the autophagic flux as an emerging common pathomechanism. We also shed light on the different steps of the autophagy pathway linked to these genes. Finally, we review the concept of autophagy being a therapeutic target in IPNs, and the possibilities and challenges of this pathway-specific targeting.
Collapse
Affiliation(s)
- Mansour Haidar
- Peripheral Neuropathy Research Group, Institute Born Bunge, University of AntwerpAntwerpen, Belgium
| | - Vincent Timmerman
- Peripheral Neuropathy Research Group, Institute Born Bunge, University of AntwerpAntwerpen, Belgium
| |
Collapse
|