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Afzali MF, Sykes MM, Burton LH, Patton KM, Lee KR, Seebart C, Vigon N, Ek R, Narez GE, Marolf AJ, Sikes KJ, Haut Donahue TL, Santangelo KS. Removal of the infrapatellar fat pad and associated synovium benefits female guinea pigs in the Dunkin Hartley model of idiopathic osteoarthritis. ANNALS OF TRANSLATIONAL MEDICINE 2024; 12:43. [PMID: 38911554 PMCID: PMC11193561 DOI: 10.21037/atm-23-1886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 04/10/2024] [Indexed: 06/25/2024]
Abstract
Background Several tissues contribute to the onset and advancement of knee osteoarthritis (OA). One tissue type that is worthy of closer evaluation, particularly in the context of sex, is the infrapatellar fat pad (IFP). We previously demonstrated that removal of the IFP had short-term beneficial effects for a cohort of male Dunkin-Hartley guinea pigs. The present project was designed to elucidate the influence of IFP removal in females of this OA-prone strain. It was hypothesized that resection of the IFP would reduce the development of OA in knees of a rodent model predisposed to the disease. Methods Female guinea pigs (n=16) were acquired at an age of 2.5 months. Surgical removal of the IFP and associated synovium complex (IFP/SC) was executed at 3 months of age. One knee had the IFP/SC resected; a comparable sham surgery was performed on the contralateral knee. All animals were subjected to voluntary enclosure monitoring and dynamic weight-bearing, as well as compulsory treadmill-based gait analysis monthly; baseline data was collected prior to surgery. Guinea pigs were euthanized at 7 months. Knees from eight animals were evaluated via histology, mRNA expression, and immunohistochemistry (IHC); knees from the remaining eight animals were allocated to microcomputed tomography (microCT), biomechanical analyses (whole joint testing and indentation relaxation testing), and atomic absorption spectroscopy (AAS). Results Fibrous connective tissue (FCT) replaced the IFP/SC. Mobility/gait data indicated that unilateral IFP/SC removal did not affect bilateral hindlimb movement. MicroCT demonstrated that osteophytes were not a significant feature of OA in this sex; however, trabecular thickness (TbTh) in medial femorae decreased in knees containing the FCT. Histopathology scores were predominantly influenced by changes in the lateral tibia, which demonstrated that histologic signs of OA were increased in knees containing the native IFP/SC versus those with the FCT. Similarly, indentation testing demonstrated higher instantaneous and equilibrium moduli in the lateral tibial articular cartilage of control knees with native IFPs. AAS of multiple tissue types associated with the knee revealed that zinc was the major trace element influenced by removal of the IFP/SC. Conclusions Our data suggest that the IFP/SC is a significant component driving knee OA in female guinea pigs and that resection of this tissue prior to disease has short-term benefits. Specifically, the formation of the FCT in place of the native tissue resulted in decreased cartilage-related OA changes, as demonstrated by reduced Osteoarthritis Research Society International (OARSI) histology scores, as well as changes in transcript, protein, and cartilage indentation analyses. Importantly, this model provides evidence that sex needs to be considered when investigating responses and associated mechanisms seen with this intervention.
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Affiliation(s)
- Maryam F. Afzali
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Madeline M. Sykes
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Lindsey H. Burton
- Department of Clinical Sciences, C. Wayne Mcllwraith Translational Medicine Institute, Colorado State University, Fort Collins, CO, USA
| | - Kayley M. Patton
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Koryn R. Lee
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Cassie Seebart
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Nicole Vigon
- Department of Biomedical Engineering, S631 Life Sciences Laboratory, University of Massachusetts Amherst, Amherst, MA, USA
| | - Ryan Ek
- Department of Biomedical Engineering, S631 Life Sciences Laboratory, University of Massachusetts Amherst, Amherst, MA, USA
| | - Gerardo E. Narez
- Department of Biomedical Engineering, S631 Life Sciences Laboratory, University of Massachusetts Amherst, Amherst, MA, USA
| | - Angela J. Marolf
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Katie J. Sikes
- Department of Clinical Sciences, C. Wayne Mcllwraith Translational Medicine Institute, Colorado State University, Fort Collins, CO, USA
| | | | - Kelly S. Santangelo
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
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Delgado-Bravo M, Hart DA, Reimer RA, Herzog W. Alterations in skeletal muscle morphology and mechanics in juvenile male Sprague Dawley rats exposed to a high-fat high-sucrose diet. Sci Rep 2023; 13:12013. [PMID: 37491416 PMCID: PMC10368627 DOI: 10.1038/s41598-023-38487-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 07/09/2023] [Indexed: 07/27/2023] Open
Abstract
Although once a health concern largely considered in adults, the obesity epidemic is now prevalent in pediatric populations. While detrimental effects on skeletal muscle function have been seen in adulthood, the effects of obesity on skeletal muscle function in childhood is not clearly understood. The purpose of this study was to determine if the consumption of a high-fat high-sucrose (HFS) diet, starting in the post-weaning period, leads to changes in skeletal muscle morphology and mechanics after 14 weeks on the HFS diet. Eighteen 3-week-old male CD-Sprague Dawley rats were randomly assigned to a HFS (C-HFS, n = 10) or standard chow diet (C-CHOW, n = 8). Outcome measures included: weekly energy intake, activity levels, oxygen consumption, body mass, body composition, metabolic profile, serum protein levels, and medial gastrocnemius gene expression, morphology, and mechanics. The main findings from this study were that C-HFS rats: (1) had a greater body mass and percent body fat than control rats; (2) showed early signs of metabolic syndrome; (3) demonstrated potential impairment in muscle remodeling; (4) produced lower relative muscle force; and (5) had a shift in the force-length relationship, indicating that the medial gastrocnemius had shorter muscle fiber lengths compared to those of C-CHOW rats. Based on the results of this study, we conclude that exposure to a HFS diet led to increased body mass, body fat percentage, and early signs of metabolic syndrome, resulting in functional deficits in MG of childhood rats.
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Affiliation(s)
- Mauricio Delgado-Bravo
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
- Carrera de Kinesiología, Departamento de Ciencias de la Salud, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - David A Hart
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada
- Department of Surgery, University of Calgary, Calgary, AB, Canada
| | - Raylene A Reimer
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada
| | - Walter Herzog
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada.
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3
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Zadoorian A, Du X, Yang H. Lipid droplet biogenesis and functions in health and disease. Nat Rev Endocrinol 2023:10.1038/s41574-023-00845-0. [PMID: 37221402 DOI: 10.1038/s41574-023-00845-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/25/2023] [Indexed: 05/25/2023]
Abstract
Ubiquitous yet unique, lipid droplets are intracellular organelles that are increasingly being recognized for their versatility beyond energy storage. Advances uncovering the intricacies of their biogenesis and the diversity of their physiological and pathological roles have yielded new insights into lipid droplet biology. Despite these insights, the mechanisms governing the biogenesis and functions of lipid droplets remain incompletely understood. Moreover, the causal relationship between the biogenesis and function of lipid droplets and human diseases is poorly resolved. Here, we provide an update on the current understanding of the biogenesis and functions of lipid droplets in health and disease, highlighting a key role for lipid droplet biogenesis in alleviating cellular stresses. We also discuss therapeutic strategies of targeting lipid droplet biogenesis, growth or degradation that could be applied in the future to common diseases, such as cancer, hepatic steatosis and viral infection.
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Affiliation(s)
- Armella Zadoorian
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Ximing Du
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia.
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4
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Mitić R, Cantoni F, Börlin CS, Post MJ, Jackisch L. A simplified and defined serum-free medium for cultivating fat across species. iScience 2022; 26:105822. [PMID: 36636339 PMCID: PMC9830212 DOI: 10.1016/j.isci.2022.105822] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 11/15/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Cultivated meat is a promising technology with the potential to mitigate the ethical and environmental issues associated with traditional meat. Fat plays a key role in the meat flavor; therefore, development of suitable adipogenic protocols for livestock is essential. The traditional adipogenic cocktail containing IBMX, dexamethasone, insulin and rosiglitazone is not food-compatible. Here, we demonstrate that of the four inducers only insulin and rosiglitazone are necessary in both serum-free (DMAD) and serum-containing media, with DMAD outperforming FBS. Two glucocorticoid receptor activators, progesterone and hydrocortisone, found in DMAD and FBS, affect differentiation homogeneity, without playing an essential role in activating adipogenic genes. Importantly, this protocol leads to mature adipocytes in 3D culture. This was demonstrated in both media types and in four species: ruminant and monogastric. We therefore propose a simplified one-step adipogenic protocol which, given the replacement of rosiglitazone by a food-compatible PPARγ agonist, is suitable for making cultivated fat.
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Affiliation(s)
- Rada Mitić
- Mosa Meat B.V., Maastricht, Limburg 6229 PM, the Netherlands
- Department of Physiology, Maastricht University, Maastricht, Limburg 6211 LK, the Netherlands
| | | | | | - Mark J. Post
- Mosa Meat B.V., Maastricht, Limburg 6229 PM, the Netherlands
- Department of Physiology, Maastricht University, Maastricht, Limburg 6211 LK, the Netherlands
| | - Laura Jackisch
- Mosa Meat B.V., Maastricht, Limburg 6229 PM, the Netherlands
- Corresponding author
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5
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Kong Y, Zhang S, Wu R, Su X, Peng D, Zhao M, Su Y. New insights into different adipokines in linking the pathophysiology of obesity and psoriasis. Lipids Health Dis 2019; 18:171. [PMID: 31521168 PMCID: PMC6745073 DOI: 10.1186/s12944-019-1115-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 09/02/2019] [Indexed: 12/13/2022] Open
Abstract
Psoriasis is a chronic, systemic, hyper-proliferative immune-mediated inflammatory skin disease. The results of epidemiological investigations have shown that psoriasis affects around 2% of the general population worldwide, and the total number of psoriasis patients is more than 6 million in China. Apart from the skin manifestations, psoriasis has been verified to associate with several metabolic comorbidities, such as insulin resistance, diabetes and obesity. However, the underlying mechanism is still not elucidated. Adipocytes, considered as the active endocrine cells, are dysfunctional in obesity which displays increased synthesis and secretion of adipokines with other modified metabolic properties. Currently, growing evidence has pointed to the central role of adipokines in adipose tissue and the immune system, providing new insights into the effect of adipokines in linking the pathophysiology of obesity and psoriasis. In this review, we summarize the current understanding of the pathological role of adipokines and the potential mechanisms whereby different adipokines link obesity and psoriasis. Furthermore, we also provide evidence which identifies a potential therapeutic target aiming at adipokines for the management of these two diseases.
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Affiliation(s)
- Yi Kong
- Department of Dermatology, Hunan Key Laboratory of Medical Epigenomics, the Second Xiangya Hospital of Central South University, 139 Renmin Middle Road, Changsha, 410011, Hunan, China
| | - Suhan Zhang
- Department of Dermatology, Hunan Key Laboratory of Medical Epigenomics, the Second Xiangya Hospital of Central South University, 139 Renmin Middle Road, Changsha, 410011, Hunan, China
| | - Ruifang Wu
- Department of Dermatology, Hunan Key Laboratory of Medical Epigenomics, the Second Xiangya Hospital of Central South University, 139 Renmin Middle Road, Changsha, 410011, Hunan, China
| | - Xin Su
- Department of Cardiovascular Medicine, the Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Daoquan Peng
- Department of Cardiovascular Medicine, the Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Ming Zhao
- Department of Dermatology, Hunan Key Laboratory of Medical Epigenomics, the Second Xiangya Hospital of Central South University, 139 Renmin Middle Road, Changsha, 410011, Hunan, China.
| | - Yuwen Su
- Department of Dermatology, Hunan Key Laboratory of Medical Epigenomics, the Second Xiangya Hospital of Central South University, 139 Renmin Middle Road, Changsha, 410011, Hunan, China.
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Abstract
PURPOSE OF REVIEW Obesity is a pandemic, yet preventable healthcare problem. Insulin resistance, diabetes mellitus, dyslipidemia, and cardiovascular complications are core manifestation of obesity. While adipose tissue is a primary site of energy storage, it is also an endocrine organ, secreting a large number of adipokines and cytokines. Nonetheless in obesity, the secretion of cytokines and free fatty acids increases significantly and is associated with the degree of adiposity and insulin resistance. Fat-specific protein 27 (FSP27) has emerged as one of the major proteins that promote physiological storage of fat in adipose tissue. RECENT FINDINGS Review of number of recent findings suggests that FSP27 plays a crucial role in physiological storage of fat within the adipose tissue especially in humans. However, in disease conditions such as obesity, FSP27 may contribute to ectopic fat accumulation in non-adipose tissue. More studies are required to highlight the tissue-specific role of FSP27, especially in humans.
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Affiliation(s)
- Shakun Karki
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, 88 East Newton St, Boston, MA, 02118, USA.
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7
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Chen L, Liu Q, Tang Q, Kuang J, Li H, Pu S, Wu T, Yang X, Li R, Zhang J, Zhang Z, Huang Y, Li Y, Zou M, Jiang W, Li T, Gong M, Zhang L, Wang H, Qu A, Xie W, He J. Hepatocyte-specific Sirt6 deficiency impairs ketogenesis. J Biol Chem 2018; 294:1579-1589. [PMID: 30530497 DOI: 10.1074/jbc.ra118.005309] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 11/15/2018] [Indexed: 02/05/2023] Open
Abstract
Sirt6 is an NADH (NAD+)-dependent deacetylase with a critical role in hepatic lipid metabolism. Ketogenesis is controlled by a signaling network of hepatic lipid metabolism. However, how Sirt6 functions in ketogenesis remains unclear. Here, we demonstrated that Sirt6 functions as a mediator of ketogenesis in response to a fasting and ketogenic diet (KD). The KD-fed hepatocyte-specific Sirt6 deficiency (HKO) mice exhibited impaired ketogenesis, which was due to enhanced Fsp27 (fat-specific induction of protein 27), a protein known to regulate lipid metabolism. In contrast, overexpression of Sirt6 in mouse primary hepatocytes promoted ketogenesis. Mechanistically, Sirt6 repressed Fsp27β expression by interacting with Crebh (cAMP response element-binding protein H) and preventing its recruitment to the Fsp27β gene promoter. The KD-fed HKO mice also showed exacerbated hepatic steatosis and inflammation. Finally, Fsp27 silencing rescued hypoketonemia and other metabolic phenotypes in KD-fed HKO mice. Our data suggest that the Sirt6-Crebh-Fsp27 axis is pivotal for hepatic lipid metabolism and inflammation. Sirt6 may be a pharmacological target to remedy metabolic diseases.
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Affiliation(s)
- Lei Chen
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Qinhui Liu
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Qin Tang
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Jiangying Kuang
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Hong Li
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Shiyun Pu
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Tong Wu
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Xuping Yang
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Rui Li
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Jinhang Zhang
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Zijing Zhang
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Ya Huang
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yanping Li
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Min Zou
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Wei Jiang
- Molecular Medicine Research Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Tao Li
- West China-Washington Mitochondria and Metabolism Center and Laboratory of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Meng Gong
- West China-Washington Mitochondria and Metabolism Center and Laboratory of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Lu Zhang
- West China-Washington Mitochondria and Metabolism Center and Laboratory of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Hua Wang
- Department of Oncology, First Affiliated Hospital of Anhui Medical University, Hefei 230022, China
| | - Aijuan Qu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China 100069
| | - Wen Xie
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260.
| | - Jinhan He
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China.
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8
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Sugisawa R, Komatsu G, Hiramoto E, Takeda N, Yamamura KI, Arai S, Miyazaki T. Independent modes of disease repair by AIM protein distinguished in AIM-felinized mice. Sci Rep 2018; 8:13157. [PMID: 30177770 PMCID: PMC6120884 DOI: 10.1038/s41598-018-31580-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/17/2018] [Indexed: 12/14/2022] Open
Abstract
Tissue macrophage-derived apoptosis inhibitor of macrophage (AIM, encoded by cd5l gene) is a circulating protein that has suppressive functions in a broad range of diseases including obesity, liver steatosis, hepatocellular carcinoma (HCC), and acute kidney injury (AKI). In healthy states, high levels of AIM circulate in the inactivated state by associating with the immunoglobulin M (IgM) pentamer in the blood, whereas during AKI, AIM dissociates from IgM and gains disease repair activity. Here, we assessed whether AIM activation via its release from IgM is required to ameliorate other diseases. To this end, we employed a mouse line in which mouse AIM was replaced with feline AIM (AIM-felinized mice). Because feline AIM rarely dissociates from IgM due to its extremely high binding affinity for IgM, these mice exhibited deficient AKI repair as in cats. When fed a high-fat diet (HFD), similar to AIM-deficient (AIM−/−) mice, AIM-felinized mice exhibited enhanced triacylglycerol deposition in visceral adipocytes and hepatocytes, resulting in more prominent obesity and fatty liver than in wild-type mice. In contrast, the incidence of HCC after a 1-year HFD was remarkably lower in AIM-felinized mice than in AIM−/− mice, suggesting that AIM produced by liver Kupffer macrophages might directly facilitate the elimination of HCC cells. Accordingly, the marked deposition of AIM accompanied by accumulation of Kupffer cells was obvious during HCC tumour development in AIM-felinized mice. Δsµ mice, which harbour almost no circulating AIM due to the lack of secreted IgM, showed a phenotype comparable with that of AIM-felinized mice in prevention of those diseases. Thus, blood AIM released from IgM contributes to suppression of obesity and fatty liver as in AKI, whereas macrophage-derived noncirculating AIM mainly prevents HCC development. Our study depicted two different modes of disease prevention/repair facilitated by AIM, which could be the basis for HCC therapy that works by increasing AIM expression in macrophages.
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Affiliation(s)
- Ryoichi Sugisawa
- Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan.,School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Ginga Komatsu
- Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Emiri Hiramoto
- Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Naoki Takeda
- Center for Animal Resources and Development, Kumamoto University, Kumamoto, 860-0811, Japan
| | - Ken-Ichi Yamamura
- Center for Animal Resources and Development, Kumamoto University, Kumamoto, 860-0811, Japan
| | - Satoko Arai
- Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Toru Miyazaki
- Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan. .,AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, 113-0033, Japan. .,Max Planck-The University of Tokyo Center for Integrative Inflammology, Tokyo, 113-0033, Japan.
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Su X, Kong Y, Peng DQ. New insights into apolipoprotein A5 in controlling lipoprotein metabolism in obesity and the metabolic syndrome patients. Lipids Health Dis 2018; 17:174. [PMID: 30053818 PMCID: PMC6064078 DOI: 10.1186/s12944-018-0833-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 07/20/2018] [Indexed: 01/01/2023] Open
Abstract
Apolipoprotein A5 (apoA5) has been identified to play an important role in lipid metabolism, specifically in triglyceride (TG) and TG-rich lipoproteins (TRLs) metabolism. Numerous evidence has demonstrated for an association between apoA5 and the increased risk of obesity and metabolic syndrome, but the mechanism remains to be fully elucidated. Recently, several studies verified that apoA5 could significantly reduce plasma TG level by stimulating lipoprotein lipase (LPL) activity, and the intracellular role of apoA5 has also been proved since apoA5 is associated with cytoplasmic lipid droplets (LDs) and affects intrahepatic TG accumulation. Furthermore, since adipocytes provide the largest storage depot for TG and play a crucial role in the development of obesity, we could infer that apoA5 also acts as a novel regulator to modulate TG storage in adipocytes. In this review, we focus on the association of gene and protein of apoA5 with obesity and metabolic syndrome, and provide new insights into the physiological role of apoA5 in humans, giving a potential therapeutic target for obesity and associated disorders.
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Affiliation(s)
- Xin Su
- Department of Cardiovascular Medicine, the Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China
| | - Yi Kong
- Department of Dermatology, Hunan Key Laboratory of Medical Epigenomics, the Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China
| | - Dao-Quan Peng
- Department of Cardiovascular Medicine, the Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China.
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10
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Dietary fat-associated osteoarthritic chondrocytes gain resistance to lipotoxicity through PKCK2/STAMP2/FSP27. Bone Res 2018; 6:20. [PMID: 30002945 PMCID: PMC6033867 DOI: 10.1038/s41413-018-0020-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 12/18/2022] Open
Abstract
Free fatty acids (FFAs), which are elevated with metabolic syndrome, are considered the principal offender exerting lipotoxicity. Few previous studies have reported a causal relationship between FFAs and osteoarthritis pathogenesis. However, the molecular mechanism by which FFAs exert lipotoxicity and induce osteoarthritis remains largely unknown. We here observed that oleate at the usual clinical range does not exert lipotoxicity while oleate at high pathological ranges exerted lipotoxicity through apoptosis in articular chondrocytes. By investigating the differential effect of oleate at toxic and nontoxic concentrations, we revealed that lipid droplet (LD) accumulation confers articular chondrocytes, the resistance to lipotoxicity. Using high fat diet-induced osteoarthritis models and articular chondrocytes treated with oleate alone or oleate plus palmitate, we demonstrated that articular chondrocytes gain resistance to lipotoxicity through protein kinase casein kinase 2 (PKCK2)—six-transmembrane protein of prostate 2 (STAMP2)—and fat-specific protein 27 (FSP27)-mediated LD accumulation. We further observed that the exertion of FFAs-induced lipotoxicity was correlated with the increased concentration of cellular FFAs freed from LDs, whether FFAs are saturated or not. In conclusion, PKCK2/STAMP2/FSP27-mediated sequestration of FFAs in LD rescues osteoarthritic chondrocytes. PKCK2/STAMP2/FSP27 should be considered for interventions against metabolic OA. Cartilage tissue deals with the stress of exposure to free fatty acids by sequestering the toxic molecules into sub-cellular oil droplets. Young Hyun Yoo from Dong-A University College of Medicine in Busan, South Korea, and coworkers exposed rat cartilage cells to increasing levels of a fatty acid called oleate, a by-product of fat metabolism, and observed that the accumulation of oil droplets conferred resistance to oleate-induced toxicity. In these rat cells and in experiments involving mouse models of osteoarthritis fed a high-fat diet, the researchers then identified three of the protective proteins needed for cartilage tissue to properly quarantine fatty acids into oil droplets. Those proteins — and their connected regulatory networks — could now serve as drug targets for treating metabolic syndrome-associated osteoarthritis.
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11
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Li J, Liu G, Zhang F, Zhang Z, Xu Y, Li Q. Role of glycoprotein 78 and cidec in hepatic steatosis. Mol Med Rep 2017; 16:1871-1877. [PMID: 28656280 PMCID: PMC5561988 DOI: 10.3892/mmr.2017.6834] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 03/20/2017] [Indexed: 12/15/2022] Open
Abstract
Hepatic glycoprotein (gp78), a membrane-anchored E3 ubiquitin ligase, has been reported to be involved in regulating lipid and energy metabolism in animals, and cell death-inducing DFFA-like effector c (cidec) has emerged as an important regulator of metabolism, which has been implicated in the process of fat differentiation. Nonalcoholic fatty liver disease is a metabolic disorder associated with hepatic steatosis. In the present study, to investigate the role of gp78 and cidec in hepatic steatosis, an in vitro cell culture model of hepatic steatosis was established, using the AML12 mouse hepatocyte cell line to assess the protein expression of gp78. The results of Oil Red O staining, phase contrast microscopy and triglyceride content detection experiments indicated that the overexpression of gp78 induced lipid accumulation, whereas gp78-knockdown led to a reduction in lipid accumulation in the AML12 cells. The increased expression of gp78 was associated with steatosis. The expression of cidec was consistent with gp78, and the colocalization of gp78 and cidec was observed on the surface of lipid droplets using immunofluorescence analysis. Furthermore, an interaction between gp78 and cidec was detected using coimmunoprecipitation analysis, and this interaction promoted lipid accumulation. Based on these data, it was hypothesized that gp78 is a regulator of hepatic steatosis, and that it may be a putative molecular mediator in metabolic diseases.
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Affiliation(s)
- Jie Li
- State Key Laboratory of Cancer Biology, Department of Pathology, Xijing Hospital, Basic Medical College, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Guocai Liu
- The Third Department of Internal Medicine, The 273 Hospital of Chinese PLA, Korla, Xinjiang 84100, P.R. China
| | - Feng Zhang
- State Key Laboratory of Cancer Biology, Department of Pathology, Xijing Hospital, Basic Medical College, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Zhiwen Zhang
- State Key Laboratory of Cancer Biology, Department of Pathology, Xijing Hospital, Basic Medical College, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Yuqiao Xu
- State Key Laboratory of Cancer Biology, Department of Pathology, Xijing Hospital, Basic Medical College, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Qing Li
- State Key Laboratory of Cancer Biology, Department of Pathology, Xijing Hospital, Basic Medical College, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
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12
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Qian H, Chen Y, Nian Z, Su L, Yu H, Chen FJ, Zhang X, Xu W, Zhou L, Liu J, Yu J, Yu L, Gao Y, Zhang H, Zhang H, Zhao S, Yu L, Xiao RP, Bao Y, Hou S, Li P, Li J, Deng H, Jia W, Li P. HDAC6-mediated acetylation of lipid droplet-binding protein CIDEC regulates fat-induced lipid storage. J Clin Invest 2017; 127:1353-1369. [PMID: 28287402 DOI: 10.1172/jci85963] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 01/19/2017] [Indexed: 12/14/2022] Open
Abstract
Obesity is characterized by aberrant fat accumulation. However, the intracellular signaling pathway that senses dietary fat and leads to fat storage remains elusive. Here, we have observed that the levels of histone deacetylase 6 (HDAC6) and the related family member HDAC10 are markedly reduced in adipose tissues of obese animals and humans. Mice with adipocyte-specific depletion of Hdac6 exhibited increased fat accumulation and reduced insulin sensitivity. In normal adipocytes, we found that reversal of P300/CBP-associated factor-induced (PCAF-induced) acetylation at K56 on cell death-inducing DFFA-like effector C (CIDEC, also known as FSP27) critically regulated lipid droplet fusion and lipid storage. Importantly, HDAC6 deacetylates CIDEC, leading to destabilization and reduced lipid droplet fusion. Accordingly, we observed elevated levels of CIDEC and its acetylated form in HDAC-deficient adipocytes as well as the adipose tissue of obese animals and humans. Fatty acids (FAs) prevented CIDEC deacetylation by promoting the dissociation of CIDEC from HDAC6, which resulted in increased association of CIDEC with PCAF on the endoplasmic reticulum. Control of CIDEC acetylation required the conversion of FAs to triacylglycerols. Thus, we have revealed a signaling axis that is involved in the coordination of nutrient availability, protein acetylation, and cellular lipid metabolic responses.
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13
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Ethanol extracts of chickpeas alter the total lipid content and expression levels of genes related to fatty acid metabolism in mouse 3T3-L1 adipocytes. Int J Mol Med 2016; 38:574-84. [PMID: 27353085 PMCID: PMC4935453 DOI: 10.3892/ijmm.2016.2654] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 05/18/2016] [Indexed: 01/21/2023] Open
Abstract
Desi-type chickpeas, which have long been used as a natural treatment for diabetes, have been reported to lower visceral adiposity, dyslipidemia and insulin resistance induced by a chronic high-fat diet in rats. In this study, in order to examine the effects of chickpeas of this type in an in vitro system, we used the 3T3-L1 mouse cell line, a subclone of Swiss 3T3 cells, which can differentiate into cells with an adipocyte-like phenotype, and we used ethanol extracts of chickpeas (ECP) instead of chickpeas. Treatment of the 3T3-L1 cells with ECP led to a decrease in the lipid content in the cells. The desaturation index, defined as monounsaturated fatty acids (MUFAs)/saturated fatty acids (SFAs), was also decreased by ECP due to an increase in the cellular content of SFAs and a decrease in the content of MUFAs. The decrease in this index may reflect a decreased reaction from SFA to MUFA, which is essential for fat storage. To confirm this hypothesis, we conducted a western blot analysis, which revealed a reduction in the amount of stearoyl-CoA desaturase 1 (SCD1), a key enzyme catalyzing the reaction from SFA to MUFA. We observed simultaneous inactivations of enzymes participating in lipogenesis, i.e., liver kinase B1 (LKB1), acetyl-CoA carboxylase (ACC) and AMPK, by phosphorylation, which may lead to the suppression of reactions from acetyl-CoA to SFA via malonyl-CoA in lipogenesis. We also investigated whether lipolysis is affected by ECP. The amount of carnitine palmitoyltransferase 1 (CPT1), an enzyme important for the oxidation of fatty acids, was increased by ECP treatment. ECP also led to an increase in uncoupling protein 2 (UCP2), reported as a key protein for the oxidation of fatty acids. All of these results obtained regarding lipogenesis and fatty acid metabolism in our in vitro system are consistent with the results previously shown in rats. We also examined the effects on SCD1 and lipid contents of ethanol extracts of Kabuli-type chickpeas, which are used worldwide. The effects were similar, but of much lesser magnitude compared to those of ECP described above. Thus, Desi-type chickpeas may prove to be effective for the treatment of diabetes, as they can alter the lipid content, thus reducing fat storage.
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14
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Lipid droplets hypertrophy: a crucial determining factor in insulin regulation by adipocytes. Sci Rep 2015; 5:8816. [PMID: 25743104 PMCID: PMC4649717 DOI: 10.1038/srep08816] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 01/27/2015] [Indexed: 01/14/2023] Open
Abstract
Lipid droplets (LDs) hypertrophy in adipocytes is the main cause of energy metabolic system dysfunction, obesity and its afflictions such as T2D. However, the role of adipocytes in linking energy metabolic disorders with insulin regulation is unknown in humans. Human adipocytes constitutively synthesize and secrete insulin, which is biologically functional. Insulin concentrations and release are fat mass- and LDs-dependent respectively. Fat reduction mediated by bariatric surgery repairs obesity-associated T2D. The expression of genes, like PCSK1 (proinsulin conversion enzyme), GCG (Glucagon), GPLD1, CD38 and NNAT, involved in insulin regulation/release were differentially expressed in pancreas and adipose tissue (AT). INS (insulin) and GCG expression reduced in human AT-T2D as compared to AT-control, but remained unchanged in pancreas in either state. Insulin levels (mRNA/protein) were higher in AT derived from prediabetes BB rats with destructed pancreatic β-cells and controls than pancreas derived from the same rats respectively. Insulin expression in 10 human primary cell types including adipocytes and macrophages is an evidence for extrapancreatic insulin-producing cells. The data suggest a crosstalk between AT and pancreas to fine-tune energy metabolic system or may minimize the metabolic damage during diabetes. This study opens new avenues towards T2D therapy with a great impact on public health.
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15
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Tanaka N, Takahashi S, Matsubara T, Jiang C, Sakamoto W, Chanturiya T, Teng R, Gavrilova O, Gonzalez FJ. Adipocyte-specific disruption of fat-specific protein 27 causes hepatosteatosis and insulin resistance in high-fat diet-fed mice. J Biol Chem 2014; 290:3092-105. [PMID: 25477509 DOI: 10.1074/jbc.m114.605980] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
White adipose tissue (WAT) functions as an energy reservoir where excess circulating fatty acids are transported to WAT, converted to triglycerides, and stored as unilocular lipid droplets. Fat-specific protein 27 (FSP27, CIDEC in humans) is a lipid-coating protein highly expressed in mature white adipocytes that contributes to unilocular lipid droplet formation. However, the influence of FSP27 in adipose tissue on whole-body energy homeostasis remains unclear. Mice with adipocyte-specific disruption of the Fsp27 gene (Fsp27(ΔAd)) were generated using an aP2-Cre transgene with the Cre/LoxP system. Upon high-fat diet feeding, Fsp27(ΔAd) mice were resistant to weight gain. In the small WAT of these mice, small adipocytes containing multilocular lipid droplets were dispersed. The expression levels of the genes associated with mitochondrial abundance and brown adipocyte identity were increased, and basal lipolytic activities were significantly augmented in adipocytes isolated from Fsp27(ΔAd) mice compared with the Fsp27(F/F) counterparts. The impaired fat-storing function in Fsp27(ΔAd) adipocytes and the resultant lipid overflow from WAT led to marked hepatosteatosis, dyslipidemia, and systemic insulin resistance in high-fat diet-treated Fsp27(ΔAd) mice. These results demonstrate a critical role for FSP27 in the storage of excess fat in WAT with minimizing ectopic fat accumulation that causes insulin-resistant diabetes and non-alcoholic fatty liver disease. This mouse model may be useful for understanding the significance of fat-storing properties of white adipocytes and the role of local FSP27 in whole-body metabolism and estimating the pathogenesis of human partial lipodystrophy caused by CIDEC mutations.
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Affiliation(s)
- Naoki Tanaka
- From the Laboratory of Metabolism, Center for Cancer Research, NCI, National Institutes of Health and
| | - Shogo Takahashi
- From the Laboratory of Metabolism, Center for Cancer Research, NCI, National Institutes of Health and
| | - Tsutomu Matsubara
- From the Laboratory of Metabolism, Center for Cancer Research, NCI, National Institutes of Health and
| | - Changtao Jiang
- From the Laboratory of Metabolism, Center for Cancer Research, NCI, National Institutes of Health and
| | | | - Tatyana Chanturiya
- Mouse Metabolism Core Laboratory, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Ruifeng Teng
- Mouse Metabolism Core Laboratory, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Oksana Gavrilova
- Mouse Metabolism Core Laboratory, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Frank J Gonzalez
- From the Laboratory of Metabolism, Center for Cancer Research, NCI, National Institutes of Health and
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16
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Grahn THM, Kaur R, Yin J, Schweiger M, Sharma VM, Lee MJ, Ido Y, Smas CM, Zechner R, Lass A, Puri V. Fat-specific protein 27 (FSP27) interacts with adipose triglyceride lipase (ATGL) to regulate lipolysis and insulin sensitivity in human adipocytes. J Biol Chem 2014; 289:12029-12039. [PMID: 24627478 DOI: 10.1074/jbc.m113.539890] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In adipocytes, lipolysis is a highly regulated process involving hormonal signals, lipid droplet-associated proteins, and lipases. The discovery of new lipid droplet-associated proteins added complexity to the current model of lipolysis. In this study, we used cultured human adipocytes to demonstrate that fat-specific protein 27 (FSP27), an abundantly expressed protein in adipocytes, regulates both basal and stimulated lipolysis by interacting with adipose triglyceride lipase (ATGL, also called desnutrin or PNPLA2). We identified a core domain of FSP27, amino acids 120-220, that interacts with ATGL to inhibit its lipolytic function and promote triglyceride storage. We also defined the role of FSP27 in free fatty acid-induced insulin resistance in adipocytes. FSP27 depletion in human adipocytes increased lipolysis and inhibited insulin signaling by decreasing AKT phosphorylation. However, reducing lipolysis by either depletion of ATGL or expression of exogenous full-length FSP27 or amino acids 120-220 protected human adipocytes against the adverse effects of free fatty acids on insulin signaling. In embryonic fibroblasts derived from ATGL KO mice, exogenous free fatty acids did not affect insulin sensitivity. Our results demonstrate a crucial role for FSP27-ATGL interactions in regulating lipolysis, triglyceride accumulation, and insulin signaling in human adipocytes.
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Affiliation(s)
- Tan Hooi Min Grahn
- Section of Endocrinology, Diabetes, and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Rajween Kaur
- Section of Endocrinology, Diabetes, and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Jun Yin
- Section of Endocrinology, Diabetes, and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Martina Schweiger
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | - Vishva Mitra Sharma
- Section of Endocrinology, Diabetes, and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Mi-Jeong Lee
- Section of Endocrinology, Diabetes, and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Yasuo Ido
- Section of Endocrinology, Diabetes, and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Cynthia M Smas
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | - Vishwajeet Puri
- Section of Endocrinology, Diabetes, and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02118.
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17
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Jüngst C, Klein M, Zumbusch A. Long-term live cell microscopy studies of lipid droplet fusion dynamics in adipocytes. J Lipid Res 2013; 54:3419-29. [PMID: 24103784 DOI: 10.1194/jlr.m042515] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During the adipogenic differentiation process of mesenchymal stem cells, lipid droplets (LDs) grow slowly by transferring lipids between each other. Recent findings hint at the possibility that a fusion pore is involved. In this study, we analyze lipid transfer data obtained in long-term label-free microscopy studies in the framework of a Hagen-Poiseuille model. The data obtained show a LD fusion process in which the lipid transfer directionality depends on the size difference between LDs, whereas the respective rates depend on the size difference and additionally on the diameter of the smaller LDs. For the data analysis, the viscosity of the transferred material has to be known. We demonstrate that a viscosity-dependent molecular rotor dye can be used to measure LD viscosities in live cells. On this basis, we calculate the diameter of a putative lipid transfer channel which appears to have a direct dependence on the diameter of the smaller of the two participating LDs.
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Affiliation(s)
- Christian Jüngst
- Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany
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18
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Grahn THM, Zhang Y, Lee MJ, Sommer AG, Mostoslavsky G, Fried SK, Greenberg AS, Puri V. FSP27 and PLIN1 interaction promotes the formation of large lipid droplets in human adipocytes. Biochem Biophys Res Commun 2013; 432:296-301. [PMID: 23399566 DOI: 10.1016/j.bbrc.2013.01.113] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 01/30/2013] [Indexed: 12/26/2022]
Abstract
Human adipocytes express high levels of two distinct lipid droplet proteins, fat specific protein 27 (FSP27; also called CIDEC), a member of the CIDE family, and perilipin1 (PLIN1), a member of the PAT family. Both proteins play a role in fat metabolism in adipocytes, but how they interact is not known. Our present study demonstrates that FSP27 and PLIN1 co-localize and interact in cultured human primary adipocytes. We also found that the C-terminal domain of FSP27, aa 120-220, interacts with PLIN1. Individual expression of exogenous FSP27 or PLIN1 increased triglyceride content and decreased glycerol release (a measure of lipolysis), but co-expression of both proteins did not further increase triglyceride content or decrease lipolysis in human adipocytes. However, the combination of PLIN1 and FSP27 increased the average size of lipid droplets or caused the formation of unilocular adipocytes. Our data suggest that FSP27 interacts with PLIN1 to regulate lipid droplet size in human adipocytes in a concerted manner.
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Affiliation(s)
- Tan Hooi Min Grahn
- Section of Endocrinology, Diabetes and Nutrition, Department of Medicine, Boston University School of Medicine, 650 Albany Street, Boston, MA 02118, USA
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19
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Akieda-Asai S, Sugiyama M, Miyazawa T, Koda S, Okano I, Senba K, Poleni PE, Hizukuri Y, Okamoto A, Yamahara K, Mutoh E, Aoyama F, Sawaguchi A, Furuya M, Miyazato M, Kangawa K, Date Y. Involvement of guanylin and GC-C in rat mesenteric macrophages in resistance to a high-fat diet. J Lipid Res 2012; 54:85-96. [PMID: 23081987 DOI: 10.1194/jlr.m029017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A high-fat diet (HFD) is a well-known contributing factor in the development of obesity. Most rats fed HFDs become obese. Those that avoid obesity when fed HFDs are considered diet resistant (DR). We performed a microarray screen to identify genes specific to the mesenteric fat of DR rats and revealed high expression of guanylin and guanylyl cyclase C (GC-C) in some subjects. Our histologic studies revealed that the cellular source of guanylin and GC-C is macrophages. Therefore, we developed double-transgenic (Tg) rats overexpressing guanylin and GC-C in macrophages and found that they were resistant to the effects of HFDs. In the mesenteric fat of HFD-fed Tg rats, Fas and perilipin mRNAs were downregulated, and those of genes involved in fatty acid oxidation were upregulated, compared with the levels in HFD-fed wild-type rats. In vitro studies demonstrated that lipid accumulation was markedly inhibited in adipocytes cocultured with macrophages expressing guanylin and GC-C and that this inhibition was reduced after treatment with guanylin- and GC-C-specific siRNAs. Our results suggest that the macrophagic guanylin-GC-C system contributes to the altered expression of genes involved in lipid metabolism, leading to resistance to obesity.
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Affiliation(s)
- Sayaka Akieda-Asai
- Frontier Science Research Center, Ultrastructural Cell Biology, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
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20
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Murphy DJ. The dynamic roles of intracellular lipid droplets: from archaea to mammals. PROTOPLASMA 2012; 249:541-85. [PMID: 22002710 DOI: 10.1007/s00709-011-0329-7] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 09/28/2011] [Indexed: 05/02/2023]
Abstract
During the past decade, there has been a paradigm shift in our understanding of the roles of intracellular lipid droplets (LDs). New genetic, biochemical and imaging technologies have underpinned these advances, which are revealing much new information about these dynamic organelles. This review takes a comparative approach by examining recent work on LDs across the whole range of biological organisms from archaea and bacteria, through yeast and Drosophila to mammals, including humans. LDs probably evolved originally in microorganisms as temporary stores of excess dietary lipid that was surplus to the immediate requirements of membrane formation/turnover. LDs then acquired roles as long-term carbon stores that enabled organisms to survive episodic lack of nutrients. In multicellular organisms, LDs went on to acquire numerous additional roles including cell- and organism-level lipid homeostasis, protein sequestration, membrane trafficking and signalling. Many pathogens of plants and animals subvert their host LD metabolism as part of their infection process. Finally, malfunctions in LDs and associated proteins are implicated in several degenerative diseases of modern humans, among the most serious of which is the increasingly prevalent constellation of pathologies, such as obesity and insulin resistance, which is associated with metabolic syndrome.
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Affiliation(s)
- Denis J Murphy
- Division of Biological Sciences, University of Glamorgan, Cardiff, CF37 4AT, UK.
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21
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Rodriguez-Cuenca S, Carobbio S, Velagapudi VR, Barbarroja N, Moreno-Navarrete JM, Tinahones FJ, Fernandez-Real JM, Orešič M, Vidal-Puig A. Peroxisome proliferator-activated receptor γ-dependent regulation of lipolytic nodes and metabolic flexibility. Mol Cell Biol 2012; 32:1555-65. [PMID: 22310664 PMCID: PMC3318581 DOI: 10.1128/mcb.06154-11] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 01/28/2012] [Indexed: 12/15/2022] Open
Abstract
Optimal lipid storage and mobilization are essential for efficient adipose tissue. Nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) regulates adipocyte differentiation and lipid deposition, but its role in lipolysis and dysregulation in obesity is not well defined. This investigation aimed to understand the molecular impact of dysfunctional PPARγ on the lipolytic axis and to explore whether these defects are also confirmed in common forms of human obesity. For this purpose, we used the P465L PPARγ mouse as a model of dysfunctional PPARγ that recapitulates the human pparγ mutation (P467L). We demonstrated that defective PPARγ impairs catecholamine-induced lipolysis. This abnormal lipolytic response is exacerbated by a state of positive energy balance in leptin-deficient ob/ob mice. We identified the protein kinase A (PKA) network as a PPARγ-dependent regulatory node of the lipolytic response. Specifically, defective PPARγ is associated with decreased basal expression of prkaca (PKAcatα) and d-akap1, the lipase genes Pnplaz (ATGL) and Lipe (HSL), and lipid droplet protein genes fsp27 and adrp in vivo and in vitro. Our data indicate that PPARγ is required for activation of the lipolytic regulatory network, dysregulation of which is an important feature of obesity-induced insulin resistance in humans.
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Affiliation(s)
- Sergio Rodriguez-Cuenca
- Department of Clinical Biochemistry, Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Stefania Carobbio
- Department of Clinical Biochemistry, Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | | | - Nuria Barbarroja
- Department of Clinical Biochemistry, Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
- Hospital Virgen de la Victoria, CIBERobn Fisiopatología de la Obesidad y Nutrición, Malaga, Spain
| | - Jose Maria Moreno-Navarrete
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomédica de Girona, CIBERobn Fisiopatología de la Obesidad y Nutrición, Girona, Spain
| | - Francisco Jose Tinahones
- Hospital Virgen de la Victoria, CIBERobn Fisiopatología de la Obesidad y Nutrición, Malaga, Spain
| | - Jose Manuel Fernandez-Real
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomédica de Girona, CIBERobn Fisiopatología de la Obesidad y Nutrición, Girona, Spain
| | - Matej Orešič
- VTT Technical Research Centre of Finland, Espoo, Finland
| | - Antonio Vidal-Puig
- Department of Clinical Biochemistry, Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
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22
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FSP27 promotes lipid droplet clustering and then fusion to regulate triglyceride accumulation. PLoS One 2011; 6:e28614. [PMID: 22194867 PMCID: PMC3237475 DOI: 10.1371/journal.pone.0028614] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 11/11/2011] [Indexed: 02/08/2023] Open
Abstract
Fat Specific Protein 27 (FSP27), a lipid droplet (LD) associated protein in adipocytes, regulates triglyceride (TG) storage. In the present study we demonstrate that FSP27 plays a key role in LD morphology to accumulate TGs. We show here that FSP27 promotes clustering of the LDs which is followed by their fusion into fewer and enlarged droplets. To map the domains of FSP27 responsible for these events, we generated GFP-fusion constructs of deletion mutants of FSP27. Microscopic analysis revealed that amino acids 173–220 of FSP27 are necessary and sufficient for both the targeting of FSP27 to LDs and the initial clustering of the droplets. Amino acids 120–140 are essential but not sufficient for LD enlargement, whereas amino acids 120–210 are necessary and sufficient for both clustering and fusion of LDs to form enlarged droplets. In addition, we found that FSP27-mediated enlargement of LDs, but not their clustering, is associated with triglyceride accumulation. These results suggest a model in which FSP27 facilitates LD clustering and then promotes their fusion to form enlarged droplets in two discrete, sequential steps, and a subsequent triglyceride accumulation.
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Ablation of a galectin preferentially expressed in adipocytes increases lipolysis, reduces adiposity, and improves insulin sensitivity in mice. Proc Natl Acad Sci U S A 2011; 108:18696-701. [PMID: 21969596 DOI: 10.1073/pnas.1109065108] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The breakdown of triglycerides, or lipolysis, is a tightly controlled process that regulates fat mobilization in accord with an animal's energy needs. It is well established that lipolysis is stimulated by hormones that signal energy demand and is suppressed by the antilipolytic hormone insulin. However, much still remains to be learned about regulation of lipolysis by intracellular signaling pathways in adipocytes. Here we show that galectin-12, a member of a β-galactoside-binding lectin family preferentially expressed by adipocytes, functions as an intrinsic negative regulator of lipolysis. Galectin-12 is primarily localized on lipid droplets and regulates lipolytic protein kinase A signaling by acting upstream of phosphodiesterase activity to control cAMP levels. Ablation of galectin-12 in mice results in increased adipocyte mitochondrial respiration, reduced adiposity, and ameliorated insulin resistance/glucose intolerance. This study identifies unique properties of this intracellular galectin that is localized to an organelle and performs a critical function in lipid metabolism. These findings add to the significant functions exhibited by intracellular galectins, and have important therapeutic implications for human metabolic disorders.
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Obesity, metabolic syndrome, and adipocytes. J Lipids 2011; 2011:721686. [PMID: 21811683 PMCID: PMC3146987 DOI: 10.1155/2011/721686] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Revised: 05/25/2011] [Accepted: 05/30/2011] [Indexed: 01/02/2023] Open
Abstract
Obesity and metabolic syndromes are examples whereby excess energy consumption and energy flux disruptions are causative agents of increased fatness. Because other, as yet elucidated, cellular factors may be involved and because potential treatments of these metabolic problems involve systemic agents that are not adipose depot-specific in their actions, should we be thinking of adipose depot-specific (cellular) treatments for these problems? For sure, whether treating obesity or metabolic syndrome, the characteristics of all adipose depot-specific adipocytes and stromal vascular cells should be considered. The focus of this paper is to begin to align metabolic dysfunctions with specific characteristics of adipocytes.
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Kang HS, Okamoto K, Kim YS, Takeda Y, Bortner CD, Dang H, Wada T, Xie W, Yang XP, Liao G, Jetten AM. Nuclear orphan receptor TAK1/TR4-deficient mice are protected against obesity-linked inflammation, hepatic steatosis, and insulin resistance. Diabetes 2011; 60:177-88. [PMID: 20864514 PMCID: PMC3012170 DOI: 10.2337/db10-0628] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
OBJECTIVE The nuclear receptor TAK1/TR4/NR2C2 is expressed in several tissues that are important in the control of energy homeostasis. In this study, we investigate whether TAK1 functions as a regulator of lipid and energy homeostasis and has a role in metabolic syndrome. RESEARCH DESIGN AND METHODS We generated TAK1-deficient (TAK1⁻(/)⁻) mice to study the function of TAK1 in the development of metabolic syndrome in aged mice and mice fed a high-fat diet (HFD). (Immuno)histochemical, biochemical, and gene expression profile analyses were performed to determine the effect of the loss of TAK1 expression on lipid homeostasis in liver and adipose tissues. In addition, insulin sensitivity, energy expenditure, and adipose-associated inflammation were compared in wild-type (WT) and TAK1⁻(/)⁻ mice fed a HFD. RESULTS TAK1-deficient (TAK1⁻(/)⁻) mice are resistant to the development of age- and HFD-induced metabolic syndrome. Histo- and biochemical analyses showed significantly lower hepatic triglyceride levels and reduced lipid accumulation in adipose tissue in TAK1⁻(/)⁻ mice compared with WT mice. Gene expression profiling analysis revealed that the expression of several genes encoding proteins involved in lipid uptake and triglyceride synthesis and storage, including Cidea, Cidec, Mogat1, and CD36, was greatly decreased in the liver and primary hepatocytes of TAK1⁻(/)⁻ mice. Restoration of TAK1 expression in TAK1⁻(/)⁻ hepatocytes induced expression of several lipogenic genes. Moreover, TAK1⁻(/)⁻ mice exhibited reduced infiltration of inflammatory cells and expression of inflammatory genes in white adipose tissue, and were resistant to the development of glucose intolerance and insulin resistance. TAK1⁻(/)⁻ mice consume more oxygen and produce more carbon dioxide than WT mice, suggesting increased energy expenditure. CONCLUSIONS Our data reveal that TAK1 plays a critical role in the regulation of energy and lipid homeostasis, and promotes the development of metabolic syndrome. TAK1 may provide a new therapeutic target in the management of obesity, diabetes, and liver steatosis.
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Affiliation(s)
- Hong Soon Kang
- Cell Biology Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Kyoko Okamoto
- Cell Biology Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Yong-Sik Kim
- Cell Biology Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Yukimasa Takeda
- Cell Biology Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Carl D. Bortner
- Laboratory of Signal Transduction, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Huaixin Dang
- Cell Biology Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Taira Wada
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Wen Xie
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Xiao-Ping Yang
- Cell Biology Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Grace Liao
- Cell Biology Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Anton M. Jetten
- Cell Biology Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
- Corresponding author: Anton M. Jetten,
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Ranjit S, Boutet E, Gandhi P, Prot M, Tamori Y, Chawla A, Greenberg AS, Puri V, Czech MP. Regulation of fat specific protein 27 by isoproterenol and TNF-α to control lipolysis in murine adipocytes. J Lipid Res 2010; 52:221-36. [PMID: 21097823 DOI: 10.1194/jlr.m008771] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The lipid droplet-associated fat specific protein 27 (FSP27) suppresses lipolysis and thereby enhances triglyceride accumulation in adipocytes. We and others have recently found FSP27 to be a remarkably short-lived protein (half-life, 15 min) due to its rapid ubiquitination and proteasomal degradation. Thus, we tested the hypothesis that lipolytic agents such as tumor necrosis factor-α (TNF-α) and isoproterenol modulate FSP27 levels to regulate FFA release. Consistent with this concept, we showed that the lipolytic actions of TNF-α, interleukin-1β (IL-1β), and IFN-γ are accompanied by marked decreases in FSP27 expression and lipid droplet size in mouse adipocytes. Similar depletion of FSP27 using short interfering RNA (siRNA) mimicked the lipolysis-enhancing effect of TNF-α, while maintaining stable FSP27 levels using expression of hemagglutinin epitope-tagged FSP27 blocked TNF-α-mediated lipolysis. In contrast, we show the robust lipolytic action of isoproterenol is paradoxically associated with increases in FSP27 levels and a delayed degradation rate corresponding to decreased ubiquitination. This catecholamine-mediated increase in FSP27 abundance, probably a feedback mechanism for restraining excessive lipolysis by catecholamines, is mimicked by forskolin or 8-bromo-cAMP treatment and is prevented by the protein kinase A (PKA) inhibitor KT5720 or by PKA depletion using siRNA. Taken together, these data identify the regulation of FSP27 as an important intermediate in the mechanism of lipolysis in adipocytes in response to TNF-α and isoproterenol.
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Affiliation(s)
- Srijana Ranjit
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
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27
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Christianson JL, Boutet E, Puri V, Chawla A, Czech MP. Identification of the lipid droplet targeting domain of the Cidea protein. J Lipid Res 2010; 51:3455-62. [PMID: 20810722 PMCID: PMC2975717 DOI: 10.1194/jlr.m009498] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Cidea, the cell death-inducing DNA fragmentation factor-α-like effector (CIDE) domain-containing protein, is targeted to lipid droplets in mouse adipocytes, where it inhibits triglyceride hydrolysis and promotes lipid storage. In mice, Cidea may prevent lipolysis by binding and shielding lipid droplets from lipase association. Here we demonstrate that human Cidea localizes with lipid droplets in both adipocyte and nonadipocyte cell lines, and we ascribe specific functions to its protein domains. Expression of full-length Cidea in undifferentiated 3T3-L1 cells or COS-1 cells increases total cellular triglyceride and strikingly alters the morphology of lipid droplets by enhancing their size and reducing their number. Remarkably, both lipid droplet binding and increased triglyceride accumulation are also elicited by expression of only the carboxy-terminal 104 amino acids, indicating this small domain directs lipid droplet targeting and triglyceride shielding. However, unlike the full-length protein, expression of the carboxy-terminus causes clustering of small lipid droplets but not the formation of large droplets, identifying a novel function of the N terminus. Furthermore, human Cidea promotes lipid storage via lipolysis inhibition, as the expression of human Cidea in fully differentiated 3T3-L1 adipocytes causes a significant decrease in basal glycerol release. Taken together, these data indicate that the carboxy-terminal domain of Cidea directs lipid droplet targeting, lipid droplet clustering, and triglyceride accumulation, whereas the amino terminal domain is required for Cidea-mediated development of enlarged lipid droplets.
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Affiliation(s)
- Jennifer L Christianson
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
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Müller MJ, Bosy-Westphal A, Heller M. 'Functional' body composition: differentiating between benign and non-benign obesity. F1000 BIOLOGY REPORTS 2009; 1:75. [PMID: 20948613 PMCID: PMC2948251 DOI: 10.3410/b1-75] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Recent body composition analyses, together with assessments of insulin resistance, aerobic fitness, and intima-media thickness of the common carotid artery, have shown that metabolically-benign obese subjects have a similar BMI, waist circumference, and subcutaneous abdominal fat compared with non-metabolically-benign obese subjects. Research has suggested that 25-30% of the obese population do not need either treatment or prevention of secondary disorders. Therefore, assessment of functional body composition should replace nutritional status-based risk assessments (such as the body mass index) in both metabolic research and clinical decision making. The concept of ‘functional’ body composition gives us a more sophisticated view on nutritional status, metabolism, endocrinology, and diseases. Knowledge of detailed body composition enables characterization of biomedical traits which will give functional evidence relating genetic variants.
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Affiliation(s)
- Manfred J Müller
- Institut für Humanernährung und Lebensmittelkunde, Agrar- und Ernährungswissenschaftliche Fakultät, Christian-Albrechts-Universität, Düsternbrooker Weg 17-19, D-24105 Kiel, Germany.
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29
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Rubio-Cabezas O, Puri V, Murano I, Saudek V, Semple RK, Dash S, Hyden CSS, Bottomley W, Vigouroux C, Magré J, Raymond-Barker P, Murgatroyd PR, Chawla A, Skepper JN, Chatterjee VK, Suliman S, Patch AM, Agarwal AK, Garg A, Barroso I, Cinti S, Czech MP, Argente J, O'Rahilly S, Savage DB. Partial lipodystrophy and insulin resistant diabetes in a patient with a homozygous nonsense mutation in CIDEC. EMBO Mol Med 2009; 1:280-7. [PMID: 20049731 PMCID: PMC2891108 DOI: 10.1002/emmm.200900037] [Citation(s) in RCA: 185] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 06/29/2009] [Accepted: 07/02/2009] [Indexed: 12/13/2022] Open
Abstract
Lipodystrophic syndromes are characterized by adipose tissue deficiency. Although rare, they are of considerable interest as they, like obesity, typically lead to ectopic lipid accumulation, dyslipidaemia and insulin resistant diabetes. In this paper we describe a female patient with partial lipodystrophy (affecting limb, femorogluteal and subcutaneous abdominal fat), white adipocytes with multiloculated lipid droplets and insulin-resistant diabetes, who was found to be homozygous for a premature truncation mutation in the lipid droplet protein cell death-inducing Dffa-like effector C (CIDEC) (E186X). The truncation disrupts the highly conserved CIDE-C domain and the mutant protein is mistargeted and fails to increase the lipid droplet size in transfected cells. In mice, Cidec deficiency also reduces fat mass and induces the formation of white adipocytes with multilocular lipid droplets, but in contrast to our patient, Cidec null mice are protected against diet-induced obesity and insulin resistance. In addition to describing a novel autosomal recessive form of familial partial lipodystrophy, these observations also suggest that CIDEC is required for unilocular lipid droplet formation and optimal energy storage in human fat.
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Affiliation(s)
- Oscar Rubio-Cabezas
- Department of Endocrinology, Hospital Infantil Universitario Niño JesúsMadrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid; MadridSpain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos IIIMadrid, Spain
| | - Vishwajeet Puri
- Program in Molecular Medicine, University of Massachusetts Medical School, WorcesterMA, USA
| | - Incoronata Murano
- Institute of Normal Human Morphology, University of AnconaAncona, Italy
| | - Vladimir Saudek
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Addenbrooke's HospitalCambridge, UK
| | - Robert K Semple
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Addenbrooke's HospitalCambridge, UK
| | - Satya Dash
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Addenbrooke's HospitalCambridge, UK
| | - Caroline S S Hyden
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Addenbrooke's HospitalCambridge, UK
| | - William Bottomley
- Metabolic Disease Group, The Wellcome Trust Sanger InstituteHinxton, UK
| | - Corinne Vigouroux
- UPMC Univ Paris 06, UMR_S938Paris, France
- INSERM, UMR_S938, Faculté de Médecine Pierre et Marie Curie, Site Saint-AntoineParis, France
- AP-HP, Hôpital Tenon, Service de Biochimie et HormonologieParis, France
| | - Jocelyne Magré
- UPMC Univ Paris 06, UMR_S938Paris, France
- INSERM, UMR_S938, Faculté de Médecine Pierre et Marie Curie, Site Saint-AntoineParis, France
| | | | - Peter R Murgatroyd
- Wellcome Trust Clinical Research Facility, Addenbrooke's HospitalCambridge, UK
| | - Anil Chawla
- Program in Molecular Medicine, University of Massachusetts Medical School, WorcesterMA, USA
| | - Jeremy N Skepper
- Multi-imaging Centre, Physiology Development & Neuroscience, University of CambridgeCambridge, UK
| | - V Krishna Chatterjee
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Addenbrooke's HospitalCambridge, UK
| | - Sara Suliman
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of OxfordOxford, UK
| | - Ann-Marie Patch
- Institute of Biomedical and Clinical Science (AM.P.), Peninsula Medical SchoolExeter, UK
| | - Anil K Agarwal
- Division of Nutrition and Metabolic Diseases, Department of Internal Medicine, Center for Human Nutrition, University of Texas Southwestern Medical Center at Dallas, DallasTX, USA
| | - Abhimanyu Garg
- Division of Nutrition and Metabolic Diseases, Department of Internal Medicine, Center for Human Nutrition, University of Texas Southwestern Medical Center at Dallas, DallasTX, USA
| | - Inês Barroso
- Metabolic Disease Group, The Wellcome Trust Sanger InstituteHinxton, UK
| | - Saverio Cinti
- Institute of Normal Human Morphology, University of AnconaAncona, Italy
| | - Michael P Czech
- Program in Molecular Medicine, University of Massachusetts Medical School, WorcesterMA, USA
| | - Jesús Argente
- Department of Endocrinology, Hospital Infantil Universitario Niño JesúsMadrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid; MadridSpain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos IIIMadrid, Spain
| | - Stephen O'Rahilly
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Addenbrooke's HospitalCambridge, UK
| | - David B Savage
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Addenbrooke's HospitalCambridge, UK
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