1
|
Abstract
Growth hormone (GH) is a pleiotropic hormone that coordinates an array of physiological processes, including effects on bone, muscle, and fat, ultimately resulting in growth. Metabolically, GH promotes anabolic action in most tissues except adipose, where its catabolic action causes the breakdown of stored triglycerides into free fatty acids (FFA). GH antagonizes insulin action via various molecular pathways. Chronic GH secretion suppresses the anti-lipolytic action of insulin and increases FFA flux into the systemic circulation; thus, promoting lipotoxicity, which causes pathophysiological problems, including insulin resistance. In this review, we will provide an update on GH-stimulated adipose lipolysis and its consequences on insulin signaling in liver, skeletal muscle, and adipose tissue. Furthermore, we will discuss the mechanisms that contribute to the diabetogenic action of GH.
Collapse
Affiliation(s)
- Rita Sharma
- Department of Biomedical Sciences, Ohio University, Athens, OH, 45701, USA
| | - John J Kopchick
- Department of Biomedical Sciences, Ohio University, Athens, OH, 45701, USA; Edison Biotechnology Institute, Ohio University, Athens, OH, 45701, USA; Diabetes Institute, Ohio University, Athens, OH, 45701, USA
| | - Vishwajeet Puri
- Department of Biomedical Sciences, Ohio University, Athens, OH, 45701, USA; Diabetes Institute, Ohio University, Athens, OH, 45701, USA
| | - Vishva M Sharma
- Department of Biomedical Sciences, Ohio University, Athens, OH, 45701, USA; Diabetes Institute, Ohio University, Athens, OH, 45701, USA.
| |
Collapse
|
2
|
Zhang L, Ding L, Shi H, Wang C, Xue C, Zhang T, Wang Y. Eicosapentaenoic acid-enriched phospholipids suppressed lipid accumulation by specific inhibition of lipid droplet-associated protein FSP27 in mice. J Sci Food Agric 2020; 100:2244-2251. [PMID: 31919850 DOI: 10.1002/jsfa.10250] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 11/22/2019] [Accepted: 01/09/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND Sea cucumber is a rich source of eicosapentaenoic acid in the form of eicosapentaenoic acid-enriched phospholipids (EPA-PL). It is known to be efficacious in preventing obesity. However, few studies have focused on the role of EPA-PL in inhibiting lipid accumulation by lipid droplets (LDs). This study first investigated the effect of EPA-PL from sea cucumber on the formation of LDs and the underlying mechanism in C57BL/6J mice. The mice were randomly divided into two groups and treated for 8 weeks or 3, 7, and 14 days with either (i) a high-sucrose diet (model group), (ii) a high-sucrose diet plus 2% EPA-PL (EPA-PL group). RESULTS Eight-week EPA-PL supplementation significantly reduced lipid accumulation and LD size in liver and white adipose tissue (WAT), which was accompanied by the decreased expression of LDs-associated protein FSP27. A 3-day EPA-PL treatment suppressed the mRNA expression of Fsp27. The mRNA level of Fsp27 reached its 'normal level' after withdrawing EPA-PL for 7 days, suggesting that EPA-PL might serve as a rapid regulator of FSP27. Furthermore, EPA-PL increased the expression of lipolysis genes Hsl and Atgl accompanied by the regulation of Pparγ in WAT. CONCLUSIONS Dietary EPA-PL from sea cucumber (Cucumaria frondosa) protected against lipid accumulation by regulating LDs-associated protein FSP27, which might provide novel evidence for the anti-obesity action of EPA-PL. © 2020 Society of Chemical Industry.
Collapse
Affiliation(s)
- Lingyu Zhang
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Lin Ding
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Haohao Shi
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Chengcheng Wang
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Changhu Xue
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
- Qingdao National Laboratory for Marine Science and Technology, Laboratory of Marine Drugs & Biological Products, Qingdao, China
| | - Tiantian Zhang
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Yuming Wang
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
- Qingdao National Laboratory for Marine Science and Technology, Laboratory of Marine Drugs & Biological Products, Qingdao, China
| |
Collapse
|
3
|
Price AM, Doner NM, Gidda SK, Jambunathan S, James CN, Schami A, Yurchenko O, Mullen RT, Dyer JM, Puri V, Chapman KD. Mouse Fat-Specific Protein 27 ( FSP27) expressed in plant cells localizes to lipid droplets and promotes lipid droplet accumulation and fusion. Biochimie 2020; 169:41-53. [PMID: 31400447 DOI: 10.1016/j.biochi.2019.08.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/05/2019] [Indexed: 10/26/2022]
Abstract
Fat-Specific Protein 27 (FSP27) belongs to a small group of vertebrate proteins containing a Cell-death Inducing DNA fragmentation factor-α-like Effector (CIDE)-C domain and is involved in lipid droplet (LD) accumulation and energy homeostasis. FSP27 is predominantly expressed in white and brown adipose tissues, as well as liver, and plays a key role in mediating LD-LD fusion. No orthologs have been identified in invertebrates or plants. In this study, we tested the function of mouse FSP27 in stably-transformed Arabidopsis thaliana leaves and seeds, as well as through transient expression in Nicotiana tabacum suspension-cultured cells and N. benthamiana leaves. Confocal microscopic analysis of plant cells revealed that, similar to ectopic expression in mammalian cells, FSP27 produced in plants 1) correctly localized to LDs, 2) accumulated at LD-LD contact sites, and 3) induced an increase in the number and size of LDs and also promoted LD clustering and fusion. Furthermore, FSP27 increased oil content in transgenic A. thaliana seeds. Given that plant oils have uses in human and animal nutrition as well as industrial uses such as biofuels and bioplastics, our results suggest that ectopic expression of FSP27 in plants represents a potential strategy for increasing oil content and energy density in bioenergy or oilseed crops.
Collapse
Affiliation(s)
- Ann M Price
- BioDiscovery Institute, Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Nathan M Doner
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Satinder K Gidda
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Srikarthika Jambunathan
- Department of Medicine, Section of Endocrinology, Diabetes and Nutrition, Boston University School of Medicine, Boston, MA, USA
| | - Christopher N James
- BioDiscovery Institute, Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Alyssa Schami
- BioDiscovery Institute, Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Olga Yurchenko
- USDA-ARS, US Arid-Land Agricultural Research Center, Maricopa, AZ, USA
| | - Robert T Mullen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - John M Dyer
- USDA-ARS, US Arid-Land Agricultural Research Center, Maricopa, AZ, USA
| | - Vishwajeet Puri
- Department of Biomedical Sciences and the Diabetes Institute, Ohio University, Athens, OH, USA
| | - Kent D Chapman
- BioDiscovery Institute, Department of Biological Sciences, University of North Texas, Denton, TX, USA.
| |
Collapse
|
4
|
Abstract
Growth hormone (GH) is a pleiotropic hormone that coordinates an array of physiological processes including growth and metabolism. GH promotes anabolic action in all tissues except adipose, where it catabolizes stored fat to release energy for the promotion of growth in other tissues. However, chronic stimulation of lipolysis by GH results in an increased flux of free fatty acids (FFAs) into systemic circulation. Hence, a sustained release of high levels of GH contributes significantly to the development of insulin resistance by antagonizing the anti-lipolytic action of insulin. The molecular pathways associated with the lipolytic effect of GH in adipose tissue however, remain elusive. Recent studies have provided molecular insights into GH-induced lipolysis and impairment of insulin signaling. This review discusses the physiological and metabolic actions of GH on adipose tissue as well as GH-mediated deregulation of the FSP27-PPARγ axis which alters adipose tissue homeostasis and contributes to the development of insulin resistance and Type 2 diabetes.
Collapse
Affiliation(s)
- Vishva M Sharma
- Department of Biomedical Sciences and Diabetes Institute, Ohio University, Athens, OH 45701, USA, E-mail:
| |
Collapse
|
5
|
Hjelholt AJ, Lee KY, Arlien-Søborg MC, Pedersen SB, Kopchick JJ, Puri V, Jessen N, Jørgensen JOL. Temporal patterns of lipolytic regulators in adipose tissue after acute growth hormone exposure in human subjects: A randomized controlled crossover trial. Mol Metab 2019; 29:65-75. [PMID: 31668393 PMCID: PMC6731350 DOI: 10.1016/j.molmet.2019.08.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/11/2019] [Accepted: 08/15/2019] [Indexed: 12/18/2022] Open
Abstract
Objective Growth hormone (GH) stimulates lipolysis, but the underlying mechanisms remain incompletely understood. We examined the effect of GH on the expression of lipolytic regulators in adipose tissue (AT). Methods In a randomized, placebo-controlled, cross-over study, nine men were examined after injection of 1) a GH bolus and 2) a GH-receptor antagonist (pegvisomant) followed by four AT biopsies. In a second study, eight men were examined in a 2 × 2 factorial design including GH infusion and 36-h fasting with AT biopsies obtained during a basal period and a hyperinsulinemic-euglycemic clamp. Expression of GH-signaling intermediates and lipolytic regulators were studied by PCR and western blotting. In addition, mechanistic experiments in mouse models and 3T3-L1 adipocytes were performed. Results The GH bolus increased circulating free fatty acids (p < 0.0001) together with phosphorylation of signal transducer and activator of transcription 5 (STAT5) (p < 0.0001) and mRNA expression of the STAT5-dependent genes cytokine-inducible SH2-containing protein (CISH) and IGF-1 in AT. This was accompanied by suppressed mRNA expression of G0/G1 switch gene 2 (G0S2) (p = 0.007) and fat specific protein 27 (FSP27) (p = 0.002) and upregulation of phosphatase and tensin homolog (PTEN) mRNA expression (p = 0.03). Suppression of G0S2 was also observed in humans after GH infusion and fasting, as well as in GH transgene mice, and in vitro studies suggested MEK-PPARγ signaling to be involved. Conclusions GH-induced lipolysis in human subjects in vivo is linked to downregulation of G0S2 and FSP27 and upregulation of PTEN in AT. Mechanistically, in vitro data suggest that GH acts via MEK to suppress PPARγ-dependent transcription of G0S2. ClinicalTrials.govNCT02782221 and NCT01209429. Acute GH exposure in human subjects in vivo stimulates lipolysis and release of FFA together with GH signaling in adipose tissue. GH-induced lipolysis is associated with suppression of G0S2 and FSP27 and upregulation of PTEN in human subjects in vivo. Inhibition of MEK and activation of PPARγ abrogate GH-induced suppression of G0S2 mRNA expression in vitro.
Collapse
Affiliation(s)
- Astrid Johannesson Hjelholt
- Medical Research Laboratory, Department of Clinical Medicine, Endocrinology and Internal Medicine, Aarhus University Hospital, Palle Juul-Jensens Boulevard 165, 8200 Aarhus N, Denmark; Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark.
| | - Kevin Y Lee
- Heritage College of Osteopathic Medicine, Ohio University, 204 Grosvenor Hall, Athens, OH 45701, USA; The Diabetes Institute, Ohio University, Konneker Research Center 108, Athens, OH 45701, USA
| | - Mai Christiansen Arlien-Søborg
- Medical Research Laboratory, Department of Clinical Medicine, Endocrinology and Internal Medicine, Aarhus University Hospital, Palle Juul-Jensens Boulevard 165, 8200 Aarhus N, Denmark; Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - Steen Bønløkke Pedersen
- Medical Research Laboratory, Department of Clinical Medicine, Endocrinology and Internal Medicine, Aarhus University Hospital, Palle Juul-Jensens Boulevard 165, 8200 Aarhus N, Denmark; Steno Diabetes Center Aarhus, Aarhus University Hospital, Hedeager 3, 2., 8200 Aarhus N, Denmark
| | - John J Kopchick
- Heritage College of Osteopathic Medicine, Ohio University, 204 Grosvenor Hall, Athens, OH 45701, USA; The Edison Biotechnology Institute, Ohio University, Konneker Research Center, 172 Water Tower Dr., Athens, OH 45701, USA
| | - Vishwajeet Puri
- Heritage College of Osteopathic Medicine, Ohio University, 204 Grosvenor Hall, Athens, OH 45701, USA; The Diabetes Institute, Ohio University, Konneker Research Center 108, Athens, OH 45701, USA
| | - Niels Jessen
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Hedeager 3, 2., 8200 Aarhus N, Denmark; Department of Clinical Pharmacology, Aarhus University Hospital, Wilh. Meyers Allé 4, 8000 Aarhus C, Denmark; Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 Aarhus C, Denmark
| | - Jens Otto L Jørgensen
- Medical Research Laboratory, Department of Clinical Medicine, Endocrinology and Internal Medicine, Aarhus University Hospital, Palle Juul-Jensens Boulevard 165, 8200 Aarhus N, Denmark; Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| |
Collapse
|
6
|
Abstract
Cell death-Inducing DNA Fragmentation Factor Alpha (DFFA)-like Effector (CIDE) proteins have emerged as lipid droplet-associated proteins that regulate fat metabolism. There are three members in the CIDE protein family—CIDEA, CIDEB, and CIDEC (also known as fat-specific protein 27 (FSP27)). CIDEA and FSP27 are primarily expressed in adipose tissue, while CIDEB is expressed in the liver. Originally, based upon their homology with DNA fragmentation factors, these proteins were identified as apoptotic proteins. However, recent studies have changed the perception of these proteins, redefining them as regulators of lipid droplet dynamics and fat metabolism, which contribute to a healthy metabolic phenotype in humans. Despite various studies in humans and gene-targeting studies in mice, the physiological roles of CIDE proteins remains elusive. This review will summarize the known physiological role and metabolic pathways regulated by the CIDE proteins in human health and disease.
Collapse
Affiliation(s)
- Mark Slayton
- Department of Biomedical Sciences and Diabetes Institute, Ohio University Heritage College of Osteopathic Medicine, Athens, OH 45701, USA.
| | - Abhishek Gupta
- Department of Biomedical Sciences and Diabetes Institute, Ohio University Heritage College of Osteopathic Medicine, Athens, OH 45701, USA.
| | - Bijinu Balakrishnan
- Department of Biomedical Sciences and Diabetes Institute, Ohio University Heritage College of Osteopathic Medicine, Athens, OH 45701, USA.
| | - Vishwajeet Puri
- Department of Biomedical Sciences and Diabetes Institute, Ohio University Heritage College of Osteopathic Medicine, Athens, OH 45701, USA.
| |
Collapse
|
7
|
Cerk IK, Wechselberger L, Oberer M. Adipose Triglyceride Lipase Regulation: An Overview. Curr Protein Pept Sci 2018; 19:221-233. [PMID: 28925902 DOI: 10.2174/1389203718666170918160110] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/07/2017] [Accepted: 09/08/2017] [Indexed: 11/22/2022]
Abstract
Adipose triglyceride lipase (ATGL) is the key-enzyme for the release of fatty acids (FAs) from triacylglycerol (TG) stores during intracellular lipolysis producing FAs used for energy production. There is growing evidence that the products and intermediates from lipolytic breakdown during the FA mobilization process also have fundamental regulatory functions affecting cell signaling, gene expression, metabolism, cell growth, cell death, and lipotoxicity. Regulation of ATGL is therefore vital for maintaining a defined balance between lipid storage and mobilization. This review addresses the regulation of ATGL activity at the post-translational level with special emphasis on protein-mediated interaction at the site of hydrolytic action, namely to the lipid droplet.
Collapse
Affiliation(s)
- Ines Katrin Cerk
- Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, A-8010 Graz, Austria
| | - Lisa Wechselberger
- Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, A-8010 Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, A-8010 Graz, Austria
| |
Collapse
|
8
|
Rajamoorthi A, Lee RG, Baldán Á. Therapeutic silencing of FSP27 reduces the progression of atherosclerosis in Ldlr -/- mice. Atherosclerosis 2018; 275:43-49. [PMID: 29859472 PMCID: PMC6113075 DOI: 10.1016/j.atherosclerosis.2018.05.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/08/2018] [Accepted: 05/23/2018] [Indexed: 11/22/2022]
Abstract
Background and aims Obesity, hepatosteatosis, and hypertriglyceridemia are components of the metabolic syndrome and independent risk factors for cardiovascular disease. The lipid droplet-associated protein CIDEC (cell death-inducing DFFA-like effector C), known in mice as FSP27 (fat-specific protein 27), plays a key role in maintaining triacylglyceride (TAG) homeostasis in adipose tissue and liver, and controls circulating TAG levels in mice. Importantly, mutations and SNPs in CIDEC are associated with dyslipidemia and altered metabolic function in humans. Here we tested whether systemic silencing of Fsp27 using antisense oligonucleotides (ASOs) was atheroprotective in LDL receptor knock-out (Ldlr−/−) mice. Methods Atheroprone Ldlr−/− mice were fed a high-fat, high-cholesterol diet for 12 weeks while simultaneously dosed with saline, ASO-ctrl, or ASO-Fsp27. Results Data show that, compared to control treatments, silencing Fsp27 significantly reduced body weight gain and visceral adiposity, prevented diet-induced hypertriglyceridemia, and reduced athero-sclerotic lesion size both in en face aortas and in the aortic root. Conclusions Our findings suggest that therapeutic silencing of Fsp27 with ASOs may be beneficial in the prevention and management of atherogenic disease in patients with metabolic syndrome.
Collapse
Affiliation(s)
- Ananthi Rajamoorthi
- Edward A. Doisy Department of Biochemistry & Molecular Biology, Saint Louis University, Saint Louis, MO, 63104, USA
| | - Richard G Lee
- Cardiovascular Group, Antisense Drug Discovery, Ionis Pharmaceuticals, Carlsbad, CA, 92010, USA
| | - Ángel Baldán
- Edward A. Doisy Department of Biochemistry & Molecular Biology, Saint Louis University, Saint Louis, MO, 63104, USA; Center for Cardiovascular Research, Saint Louis, MO, 63104, USA; Liver Center, Saint Louis University, Saint Louis, MO, 63104, USA.
| |
Collapse
|
9
|
Liu L, Zheng LD, Zou P, Brooke J, Smith C, Long YC, Almeida FA, Liu D, Cheng Z. FoxO1 antagonist suppresses autophagy and lipid droplet growth in adipocytes. Cell Cycle 2016; 15:2033-41. [PMID: 27260854 DOI: 10.1080/15384101.2016.1192732] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Obesity and related metabolic disorders constitute one of the most pressing heath concerns worldwide. Increased adiposity is linked to autophagy upregulation in adipose tissues. However, it is unknown how autophagy is upregulated and contributes to aberrant adiposity. Here we show a FoxO1-autophagy-FSP27 axis that regulates adipogenesis and lipid droplet (LD) growth in adipocytes. Adipocyte differentiation was associated with upregulation of autophagy and fat specific protein 27 (FSP27), a key regulator of adipocyte maturation and expansion by promoting LD formation and growth. However, FoxO1 specific inhibitor AS1842856 potently suppressed autophagy, FSP27 expression, and adipocyte differentiation. In terminally differentiated adipocytes, AS1842856 significantly reduced FSP27 level and LD size, which was recapitulated by autophagy inhibitors (bafilomycin-A1 and leupeptin, BL). Similarly, AS1842856 and BL dampened autophagy activity and FSP27 expression in explant cultures of white adipose tissue. To our knowledge, this is the first study addressing FoxO1 in the regulation of adipose autophagy, shedding light on the mechanism of increased autophagy and adiposity in obese individuals. Given that adipogenesis and adipocyte expansion contribute to aberrant adiposity, targeting the FoxO1-autophagy-FSP27 axis may lead to new anti-obesity options.
Collapse
Affiliation(s)
- Longhua Liu
- a Department of Human Nutrition, Foods, and Exercise , Fralin Life Science Institute, College of Agriculture and Life Science, Virginia Tech , Blacksburg , VA , USA
| | - Louise D Zheng
- a Department of Human Nutrition, Foods, and Exercise , Fralin Life Science Institute, College of Agriculture and Life Science, Virginia Tech , Blacksburg , VA , USA
| | - Peng Zou
- a Department of Human Nutrition, Foods, and Exercise , Fralin Life Science Institute, College of Agriculture and Life Science, Virginia Tech , Blacksburg , VA , USA
| | - Joseph Brooke
- a Department of Human Nutrition, Foods, and Exercise , Fralin Life Science Institute, College of Agriculture and Life Science, Virginia Tech , Blacksburg , VA , USA
| | - Cayleen Smith
- a Department of Human Nutrition, Foods, and Exercise , Fralin Life Science Institute, College of Agriculture and Life Science, Virginia Tech , Blacksburg , VA , USA
| | - Yun Chau Long
- b Department of Biochemistry , Yong Loo Lin School of Medicine, National University of Singapore , Singapore
| | - Fabio A Almeida
- a Department of Human Nutrition, Foods, and Exercise , Fralin Life Science Institute, College of Agriculture and Life Science, Virginia Tech , Blacksburg , VA , USA.,c Department of Health Promotion, Social & Behavioral Health , College of Public Health, University of Nebraska Medical Center , Omaha , NE , USA
| | - Dongmin Liu
- a Department of Human Nutrition, Foods, and Exercise , Fralin Life Science Institute, College of Agriculture and Life Science, Virginia Tech , Blacksburg , VA , USA
| | - Zhiyong Cheng
- a Department of Human Nutrition, Foods, and Exercise , Fralin Life Science Institute, College of Agriculture and Life Science, Virginia Tech , Blacksburg , VA , USA
| |
Collapse
|
10
|
Lee SM, Jang TH, Park HH. Molecular basis for homo-dimerization of the CIDE domain revealed by the crystal structure of the CIDE-N domain of FSP27. Biochem Biophys Res Commun 2013; 439:564-9. [PMID: 24025675 DOI: 10.1016/j.bbrc.2013.09.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 09/03/2013] [Indexed: 12/12/2022]
Abstract
FSP27 (CIDE-3 in humans) plays critical roles in lipid metabolism and apoptosis and is known to be involved in regulation of lipid droplet (LD) size and lipid storage and apoptotic DNA fragmentation. Given that CIDE-containing proteins including FSP27 are associated with many human diseases including cancer, aging, diabetes, and obesity, studies of FSP27 and other CIDE-containing proteins are of great biological importance. As a first step toward elucidating the molecular mechanisms of FSP27-mediated lipid droplet growth and apoptosis, we report the crystal structure of the CIDE-N domain of FSP27 at a resolution of 2.0 Å. The structure revealed a possible biologically important homo-dimeric interface similar to that formed by the hetero-dimeric complex, CAD/ICAD. Comparison with other structural homologues revealed that the PB1 domain of BEM1P, ubiquitin-like domain of BAG6 and ubiquitin are structurally similar proteins. Our homo-dimeric structure of the CIDE-N domain of FSP27 will provide important information that will enable better understanding of the function of FSP27.
Collapse
Affiliation(s)
- Seung Mi Lee
- School of Biotechnology and Graduate School of Biochemistry at Yeungnam University, Gyeongsan, South Korea
| | | | | |
Collapse
|
11
|
Guebre-Egziabher F, Alix PM, Koppe L, Pelletier CC, Kalbacher E, Fouque D, Soulage CO. Ectopic lipid accumulation: A potential cause for metabolic disturbances and a contributor to the alteration of kidney function. Biochimie 2013; 95:1971-9. [PMID: 23896376 DOI: 10.1016/j.biochi.2013.07.017] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 07/18/2013] [Indexed: 01/06/2023]
Abstract
Ectopic lipid accumulation is now known to be a mechanism that contributes to organ injury in the context of metabolic diseases. In muscle and liver, accumulation of lipids impairs insulin signaling. This hypothesis accounts for the mechanism of insulin resistance in obesity, type 2 diabetes, aging and lipodystrophy. Increasing data suggest that lipid accumulation in the kidneys could also contribute to the alteration of kidney function in the context of metabolic syndrome and obesity. Furthermore and more unexpectedly, animal models of kidney disease exhibit a decreased adiposity and ectopic lipid redistribution suggesting that kidney disease may be a state of lipodystrophy. However, whether this abnormal lipid partitioning during chronic kidney disease (CKD) may have any functional impact in these tissues needs to be investigated. Here, we provide a perspective by defining the problem and analyzing the possible causes and consequences. Further human studies are required to strengthen these observations, and provide novel therapeutic approaches.
Collapse
Affiliation(s)
- Fitsum Guebre-Egziabher
- Université de Lyon, INSERM U1060, CarMeN, INSA de Lyon, Univ Lyon-1, F-69621 Villeurbanne, France; Hospices Civils de Lyon, Department of Nephrology, Hôpital E Herriot, Lyon F-69003, France.
| | | | | | | | | | | | | |
Collapse
|