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Lee MJ, Kim J. The pathophysiology of visceral adipose tissues in cardiometabolic diseases. Biochem Pharmacol 2024; 222:116116. [PMID: 38460909 DOI: 10.1016/j.bcp.2024.116116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/21/2024] [Accepted: 03/06/2024] [Indexed: 03/11/2024]
Abstract
Central pattern of fat distribution, especially fat accumulation within the intraabdominal cavity increases risks for cardiometabolic diseases. Portal hypothesis combined with a pathological remodeling in visceral fat is considered the major etiological factor explaining the independent contribution of visceral obesity to cardiometabolic diseases. Excessive remodeling in visceral fat during development of obesity leads to dysfunctions in the depot, characterized by hypertrophy and death of adipocytes, hypoxia, inflammation, and fibrosis. Dysfunctional visceral fat secretes elevated levels of fatty acids, glycerol, and proinflammatory and profibrotic cytokines into the portal vein directly impacting the liver, the central regulator of systemic metabolism. These metabolic and endocrine products induce ectopic fat accumulation, insulin resistance, inflammation, and fibrosis in the liver, which in turn causes or exacerbates systemic metabolic derangements. Elucidation of underlying mechanisms that lead to the pathological remodeling and higher degree of dysfunctions in visceral adipose tissue is therefore, critical for the development of therapeutics to prevent deleterious sequelae in obesity. We review depot differences in metabolic and endocrine properties and expendabilities as well as underlying mechanisms that contribute to the pathophysiological aspects of visceral adiposity in cardiometabolic diseases. We also discuss impacts of different weight loss interventions on visceral adiposity and cardiometabolic diseases.
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Affiliation(s)
- Mi-Jeong Lee
- Department of Human Nutrition, Food and Animal Sciences, University of Hawaii at Manoa, Hawaii 96822, USA.
| | - Jeehoon Kim
- Department of Sociology, Social Work, and Criminology, Idaho State University, Idaho 83209, USA
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Ruppert PMM, Michielsen CCJR, Hazebroek EJ, Pirayesh A, Olivecrona G, Afman LA, Kersten S. Fasting induces ANGPTL4 and reduces LPL activity in human adipose tissue. Mol Metab 2020; 40:101033. [PMID: 32504883 PMCID: PMC7334813 DOI: 10.1016/j.molmet.2020.101033] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 05/28/2020] [Accepted: 05/31/2020] [Indexed: 02/06/2023] Open
Abstract
Objective Studies in mice have shown that the decrease in lipoprotein lipase (LPL) activity in adipose tissue upon fasting is mediated by induction of the inhibitor ANGPTL4. Here, we aimed to validate this concept in humans by determining the effect of a prolonged fast on ANGPTL4 and LPL gene and protein expression in human subcutaneous adipose tissue. Methods Twenty-three volunteers ate a standardized meal at 18.00 h and fasted until 20.00 h the next day. Blood was drawn and periumbilical adipose tissue biopsies were collected 2 h and 26 h after the meal. Results Consistent with previous mouse data, LPL activity in human adipose tissue was significantly decreased by fasting (−60%), concurrent with increased ANGPTL4 mRNA (+90%) and decreased ANGPTL8 mRNA (−94%). ANGPTL4 protein levels in adipose tissue were also significantly increased by fasting (+46%), whereas LPL mRNA and protein levels remained unchanged. In agreement with the adipose tissue data, plasma ANGPTL4 levels increased upon fasting (+100%), whereas plasma ANGPTL8 decreased (−79%). Insulin, levels of which significantly decreased upon fasting, downregulated ANGPTL4 mRNA and protein in primary human adipocytes. By contrast, cortisol, levels of which significantly increased upon fasting, upregulated ANGPTL4 mRNA and protein in primary human adipocytes as did fatty acids. Conclusion ANGPTL4 levels in human adipose tissue are increased by fasting, likely via increased plasma cortisol and free fatty acids and decreased plasma insulin, resulting in decreased LPL activity. This clinical trial was registered with identifier NCT03757767. 24-h fast in humans reduces LPL activity in subcutaneous adipose tissue. 24-h fast in humans increases adipose ANGPTL4 mRNA, protein, and plasma ANGPTL4 levels. Cortisol, fatty acids, and insulin regulate ANGPTL4 in vitro. ANGPTL4 mediates the reduction in adipose LPL activity during fasting. 24-h fast in humans decreases adipose ANGPTL8 mRNA and plasma ANGPTL8 levels.
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Affiliation(s)
- Philip M M Ruppert
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Wageningen, the Netherlands
| | - Charlotte C J R Michielsen
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Wageningen, the Netherlands
| | - Eric J Hazebroek
- Department of Bariatric Surgery, Rijnstate Hospital/Vitalys Clinic, Arnhem, the Netherlands; Nutrition and Disease Group, Division of Human Nutrition and Health, Wageningen University, Wageningen, the Netherlands
| | - Ali Pirayesh
- Amsterdam Plastic Surgery, Amsterdam, the Netherlands
| | - Gunilla Olivecrona
- Department of Medical Biosciences/Physiological Chemistry, Umeå University, Umeå, Sweden
| | - Lydia A Afman
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Wageningen, the Netherlands
| | - Sander Kersten
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Wageningen, the Netherlands.
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Xue Y, Wu Y, Wang Q, Xue L, Su Z, Zhang C. Cellular Vehicles Based on Neutrophils Enable Targeting of Atherosclerosis. Mol Pharm 2019; 16:3109-3120. [PMID: 31082253 DOI: 10.1021/acs.molpharmaceut.9b00342] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Given the multiple interactions between neutrophils (NEs) and atherosclerosis (AS), in this study, we exploited NEs as cellular vehicles loaded with cationic liposomes for actively targeting atherosclerotic sites. The cellular vehicles based on NEs possess efficient internalization of cationic liposomes and sensitive response to the chemotaxis of atherosclerotic inflammatory cells, which ultimately realize the targeted delivery of the cargos into the target cells in vitro. Moreover, these effects also translated to significant enhancement of the accumulation of NEs' cargos into the atherosclerotic plaque in vivo after administering NE vehicles to the AS animal model. Consequently, cellular vehicles based on NEs could be a novel strategy for targeted delivery of payloads into atherosclerotic plaque, which would facilitate theranostics for AS and the development of anti-AS drugs to manage the disease.
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Affiliation(s)
- Yanan Xue
- State Key Laboratory of Natural Medicines Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases Center of Advanced Pharmaceuticals and Biomaterials , China Pharmaceutical University , No. 24 Tongjiaxiang , Nanjing 210009 , China
| | - Yue Wu
- State Key Laboratory of Natural Medicines Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases Center of Advanced Pharmaceuticals and Biomaterials , China Pharmaceutical University , No. 24 Tongjiaxiang , Nanjing 210009 , China
| | - Qianqian Wang
- State Key Laboratory of Natural Medicines Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases Center of Advanced Pharmaceuticals and Biomaterials , China Pharmaceutical University , No. 24 Tongjiaxiang , Nanjing 210009 , China
| | - Lingjing Xue
- State Key Laboratory of Natural Medicines Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases Center of Advanced Pharmaceuticals and Biomaterials , China Pharmaceutical University , No. 24 Tongjiaxiang , Nanjing 210009 , China
| | - Zhigui Su
- State Key Laboratory of Natural Medicines Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases Center of Advanced Pharmaceuticals and Biomaterials , China Pharmaceutical University , No. 24 Tongjiaxiang , Nanjing 210009 , China
| | - Can Zhang
- State Key Laboratory of Natural Medicines Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases Center of Advanced Pharmaceuticals and Biomaterials , China Pharmaceutical University , No. 24 Tongjiaxiang , Nanjing 210009 , China
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Blomquist C, Chorell E, Ryberg M, Mellberg C, Worrsjö E, Makoveichuk E, Larsson C, Lindahl B, Olivecrona G, Olsson T. Decreased lipogenesis-promoting factors in adipose tissue in postmenopausal women with overweight on a Paleolithic-type diet. Eur J Nutr 2017; 57:2877-2886. [PMID: 29075849 PMCID: PMC6267391 DOI: 10.1007/s00394-017-1558-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 10/13/2017] [Indexed: 01/19/2023]
Abstract
Purpose We studied effects of diet-induced postmenopausal weight loss on gene expression and activity of proteins involved in lipogenesis and lipolysis in adipose tissue. Methods Fifty-eight postmenopausal women with overweight (BMI 32.5 ± 5.5) were randomized to eat an ad libitum Paleolithic-type diet (PD) aiming for a high intake of protein and unsaturated fatty acids or a prudent control diet (CD) for 24 months. Anthropometry, plasma adipokines, gene expression of proteins involved in fat metabolism in subcutaneous adipose tissue (SAT) and lipoprotein lipase (LPL) activity and mass in SAT were measured at baseline and after 6 months. LPL mass and activity were also measured after 24 months. Results The PD led to improved insulin sensitivity (P < 0.01) and decreased circulating triglycerides (P < 0.001), lipogenesis-related factors, including LPL mRNA (P < 0.05), mass (P < 0.01), and activity (P < 0.001); as well as gene expressions of CD36 (P < 0.05), fatty acid synthase, FAS (P < 0.001) and diglyceride acyltransferase 2, DGAT2 (P < 0.001). The LPL activity (P < 0.05) and gene expression of DGAT2 (P < 0.05) and FAS (P < 0.05) were significantly lowered in the PD group versus the CD group at 6 months and the LPL activity (P < 0.05) remained significantly lowered in the PD group compared to the CD group at 24 months. Conclusions Compared to the CD, the PD led to a more pronounced reduction of lipogenesis-promoting factors in SAT among postmenopausal women with overweight. This could have mediated the favorable metabolic effects of the PD on triglyceride levels and insulin sensitivity.
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Affiliation(s)
- Caroline Blomquist
- Department of Public Health and Clinical Medicine, Medicine, Umeå University, By 6M, M31, SE-901 87, Umeå, Sweden.
| | - Elin Chorell
- Department of Public Health and Clinical Medicine, Medicine, Umeå University, By 6M, M31, SE-901 87, Umeå, Sweden
| | - Mats Ryberg
- Department of Public Health and Clinical Medicine, Medicine, Umeå University, By 6M, M31, SE-901 87, Umeå, Sweden
| | - Caroline Mellberg
- Department of Public Health and Clinical Medicine, Medicine, Umeå University, By 6M, M31, SE-901 87, Umeå, Sweden
| | - Evelina Worrsjö
- Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine, Umeå University, Umeå, Sweden
| | - Elena Makoveichuk
- Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine, Umeå University, Umeå, Sweden
| | - Christel Larsson
- Department of Food and Nutrition and Sport Science, University of Gothenburg, Gothenburg, Sweden
| | - Bernt Lindahl
- Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine, Umeå University, Umeå, Sweden
| | | | - Tommy Olsson
- Department of Public Health and Clinical Medicine, Medicine, Umeå University, By 6M, M31, SE-901 87, Umeå, Sweden
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Studies on the lipase-induced degradation of lipid-based drug delivery systems. Part II – Investigations on the mechanisms leading to collapse of the lipid structure. Eur J Pharm Biopharm 2013; 84:456-63. [DOI: 10.1016/j.ejpb.2012.12.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 12/03/2012] [Accepted: 12/21/2012] [Indexed: 11/21/2022]
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Abstract
Excess intra-abdominal adipose tissue accumulation, often termed visceral obesity, is part of a phenotype including dysfunctional subcutaneous adipose tissue expansion and ectopic triglyceride storage closely related to clustering cardiometabolic risk factors. Hypertriglyceridemia; increased free fatty acid availability; adipose tissue release of proinflammatory cytokines; liver insulin resistance and inflammation; increased liver VLDL synthesis and secretion; reduced clearance of triglyceride-rich lipoproteins; presence of small, dense LDL particles; and reduced HDL cholesterol levels are among the many metabolic alterations closely related to this condition. Age, gender, genetics, and ethnicity are broad etiological factors contributing to variation in visceral adipose tissue accumulation. Specific mechanisms responsible for proportionally increased visceral fat storage when facing positive energy balance and weight gain may involve sex hormones, local cortisol production in abdominal adipose tissues, endocannabinoids, growth hormone, and dietary fructose. Physiological characteristics of abdominal adipose tissues such as adipocyte size and number, lipolytic responsiveness, lipid storage capacity, and inflammatory cytokine production are significant correlates and even possible determinants of the increased cardiometabolic risk associated with visceral obesity. Thiazolidinediones, estrogen replacement in postmenopausal women, and testosterone replacement in androgen-deficient men have been shown to favorably modulate body fat distribution and cardiometabolic risk to various degrees. However, some of these therapies must now be considered in the context of their serious side effects. Lifestyle interventions leading to weight loss generally induce preferential mobilization of visceral fat. In clinical practice, measuring waist circumference in addition to the body mass index could be helpful for the identification and management of a subgroup of overweight or obese patients at high cardiometabolic risk.
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Affiliation(s)
- André Tchernof
- Endocrinology and Genomics Axis, Centre Hospitalier Universitaire de Québec, Québec, Canada
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Pereira MJ, Palming J, Rizell M, Aureliano M, Carvalho E, Svensson MK, Eriksson JW. The immunosuppressive agents rapamycin, cyclosporin A and tacrolimus increase lipolysis, inhibit lipid storage and alter expression of genes involved in lipid metabolism in human adipose tissue. Mol Cell Endocrinol 2013; 365:260-9. [PMID: 23160140 DOI: 10.1016/j.mce.2012.10.030] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 10/15/2012] [Accepted: 10/30/2012] [Indexed: 02/07/2023]
Abstract
Cyclosporin A (CsA), tacrolimus and rapamycin are immunosuppressive agents (IAs) associated with insulin resistance and dyslipidemia, although their molecular effects on lipid metabolism in adipose tissue are unknown. We explored IAs effects on lipolysis, lipid storage and expression of genes involved on lipid metabolism in isolated human adipocytes and/or adipose tissue obtained via subcutaneous and omental fat biopsies. CsA, tacrolimus and rapamycin increased isoproterenol-stimulated lipolysis and inhibited lipid storage by 20-35% and enhanced isoproterenol-stimulated hormone-sensitive lipase Ser552 phosphorylation. Rapamycin also increased basal lipolysis (~20%) and impaired insulin's antilipolytic effect. Rapamycin, down-regulated the gene expression of perilipin, sterol regulatory element-binding protein 1 (SREBP1) and lipin 1, while tacrolimus down-regulated CD36 and aP2 gene expression. All three IAs increased IL-6 gene expression and secretion, but not expression and secretion of TNF-α or adiponectin. These findings suggest that CsA, tacrolimus and rapamycin enhance lipolysis, inhibit lipid storage and expression of lipogenic genes in adipose tissue, which may contribute to the development of dyslipidemia and insulin resistance associated with immunosuppressive therapy.
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Affiliation(s)
- Maria J Pereira
- The Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, The Sahlgrenska Academy at University of Gothenburg, 413 45 Gothenburg, Sweden.
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Nyrén R, Chang CL, Lindström P, Barmina A, Vorrsjö E, Ali Y, Juntti-Berggren L, Bensadoun A, Young SG, Olivecrona T, Olivecrona G. Localization of lipoprotein lipase and GPIHBP1 in mouse pancreas: effects of diet and leptin deficiency. BMC PHYSIOLOGY 2012. [PMID: 23186339 PMCID: PMC3537605 DOI: 10.1186/1472-6793-12-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Lipoprotein lipase (LPL) hydrolyzes triglycerides in plasma lipoproteins and enables uptake of lipolysis products for energy production or storage in tissues. Our aim was to study the localization of LPL and its endothelial anchoring protein glycosylphosphatidylinositol-anchored high density lipoprotein-binding protein 1 (GPIHBP1) in mouse pancreas, and effects of diet and leptin deficiency on their expression patterns. For this, immunofluorescence microscopy was used on pancreatic tissue from C57BL/6 mouse embryos (E18), adult mice on normal or high-fat diet, and adult ob/ob-mice treated or not with leptin. The distribution of LPL and GPIHBP1 was compared to insulin, glucagon and CD31. Heparin injections were used to discriminate between intracellular and extracellular LPL. RESULTS In the exocrine pancreas LPL was found in capillaries, and was mostly co-localized with GPIHBP1. LPL was releasable by heparin, indicating localization on cell surfaces. Within the islets, most of the LPL was associated with beta cells and could not be released by heparin, indicating that the enzyme remained mostly within cells. Staining for LPL was found also in the glucagon-producing alpha cells, both in embryos (E18) and in adult mice. Only small amounts of LPL were found together with GPIHBP1 within the capillaries of islets. Neither a high fat diet nor fasting/re-feeding markedly altered the distribution pattern of LPL or GPIHBP1 in mouse pancreas. Islets from ob/ob mice appeared completely deficient of LPL in the beta cells, while LPL-staining was normal in alpha cells and in the exocrine pancreas. Leptin treatment of ob/ob mice for 12 days reversed this pattern, so that most of the islets expressed LPL in beta cells. CONCLUSIONS We conclude that both LPL and GPIHBP1 are present in mouse pancreas, and that LPL expression in beta cells is dependent on leptin.
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Affiliation(s)
- Rakel Nyrén
- Department of Medical Biosciences/Physiological Chemistry, Umeå University, Umeå, Sweden
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Wronska A, Kmiec Z. Structural and biochemical characteristics of various white adipose tissue depots. Acta Physiol (Oxf) 2012; 205:194-208. [PMID: 22226221 DOI: 10.1111/j.1748-1716.2012.02409.x] [Citation(s) in RCA: 240] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 09/29/2011] [Accepted: 01/02/2012] [Indexed: 12/11/2022]
Abstract
It is now widely accepted that white adipose tissue (WAT) is not merely a fuel storage organ, but also a key component of metabolic homoeostatic mechanisms. Apart from its major role in lipid and glucose metabolism, adipose tissue is also involved in a wide array of other biological processes. The hormones and adipokines, as well as other biologically active agents released from fat cells, affect many physiological and pathological processes. WAT is neither uniform nor inflexible because it undergoes constant remodelling, adapting the size and number of adipocytes to changes in nutrients' availability and hormonal milieu. Fat depots from different areas of the body display distinct structural and functional properties and have disparate roles in pathology. The two major types of WAT are visceral fat, localized within the abdominal cavity and mediastinum, and subcutaneous fat in the hypodermis. Visceral obesity correlates with increased risk of insulin resistance and cardiovascular diseases, while increase of subcutaneous fat is associated with favourable plasma lipid profiles. Visceral adipocytes show higher lipogenic and lipolytic activities and produce more pro-inflammatory cytokines, while subcutaneous adipocytes are the main source of leptin and adiponectin. Moreover, adipose tissue associated with skeletal muscles (intramyocellular and intermuscular fat) and with the epicardium is believed to provide fuels for skeletal and cardiac muscle contraction. However, increased mass of either epicardial or intermuscular adipose tissue correlates with cardiovascular risk, while the presence of the intramyocellular fat is a risk factor for the development of insulin resistance. This review summarizes results of mainly human studies related to the differential characteristics of various WAT depots.
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Affiliation(s)
- A. Wronska
- Department of Histology; Medical Faculty; Medical University of Gdansk; Gdansk; Poland
| | - Z. Kmiec
- Department of Histology; Medical Faculty; Medical University of Gdansk; Gdansk; Poland
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Ruge T, Sukonina V, Kroupa O, Makoveichuk E, Lundgren M, Svensson MK, Olivecrona G, Eriksson JW. Effects of hyperinsulinemia on lipoprotein lipase, angiopoietin-like protein 4, and glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 in subjects with and without type 2 diabetes mellitus. Metabolism 2012; 61:652-60. [PMID: 22078753 DOI: 10.1016/j.metabol.2011.09.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 09/27/2011] [Indexed: 11/22/2022]
Abstract
Our aims were to compare the systemic effects of insulin on lipoprotein lipase (LPL) in tissues from subjects with different degrees of insulin sensitivity. The effects of insulin on LPL during a 4-hour hyperinsulinemic, euglycemic clamp were studied in skeletal muscle, adipose tissue, and postheparin plasma from young healthy subjects (YS), older subjects with type 2 diabetes mellitus (DS), and older control subjects (CS). In addition, we studied the effects of insulin on the expression of 2 recently recognized candidate genes for control of LPL activity: angiopoietin-like protein 4 (ANGPTL4) and glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1. As an effect of insulin, LPL activity decreased by 20% to 25% in postheparin plasma and increased by 20% to 30% in adipose tissue in all groups. In YS, the levels of ANGPTL4 messenger RNA in adipose tissue decreased 3-fold during the clamp. In contrast, there was no significant change in DS or CS. Regression analysis showed that the ability of insulin to reduce the expression of ANGPTL4 was positively correlated with M-values and inversely correlated with factors linked to the metabolic syndrome. Expression of glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 tended to be higher in YS than in DS or CS, but the expression was not affected by insulin in any of the groups. Our data imply that the insulin-mediated regulation of LPL is not directly linked to the control of glucose turnover by insulin or to ANGPTL4 expression in adipose tissue or plasma. Interestingly, the response of ANGPTL4 expression in adipose tissue to insulin was severely blunted in both DS and CS.
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Affiliation(s)
- Toralph Ruge
- Department of Surgery and Peri-Operative Sciences/Surgery, Umeå University, SE-901 85 Umeå, Sweden.
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Hosseini M, Ehrhardt N, Weissglas-Volkov D, Lai CM, Mao HZ, Liao JL, Nikkola E, Bensadoun A, Taskinen MR, Doolittle MH, Pajukanta P, Péterfy M. Transgenic expression and genetic variation of Lmf1 affect LPL activity in mice and humans. Arterioscler Thromb Vasc Biol 2012; 32:1204-10. [PMID: 22345169 DOI: 10.1161/atvbaha.112.245696] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Lipoprotein lipase (LPL) is a principal enzyme in lipoprotein metabolism, tissue lipid utilization, and energy metabolism. LPL is synthesized by parenchymal cells in adipose, heart, and muscle tissues followed by secretion to extracellular sites, where lipolyic function is exerted. The catalytic activity of LPL is attained during posttranslational maturation, which involves glycosylation, folding, and subunit assembly within the endoplasmic reticulum. A lipase-chaperone, lipase maturation factor 1 (Lmf1), has recently emerged as a critical factor in this process. Previous studies demonstrated that loss-of-function mutations of Lmf1 result in diminished lipase activity and severe hypertriglyceridemia in mice and human subjects. The objective of this study is to investigate whether, beyond its role as a required factor in lipase maturation, variation in Lmf1 expression is sufficient to modulate LPL activity in vivo. METHODS AND RESULTS To assess the effects of Lmf1 overexpression in adipose and muscle tissues, we generated aP2-Lmf1 and Mck-Lmf1 transgenic mice. Characterization of relevant tissues revealed increased LPL activity in both mouse strains. In the omental and subcutaneous adipose depots, Lmf1 overexpression was associated with increased LPL specific activity without changes in LPL mass. In contrast, increased LPL activity was due to elevated LPL protein level in heart and gonadal adipose tissue. To extend these studies to humans, we detected association between LMF1 gene variants and postheparin LPL activity in a dyslipidemic cohort. CONCLUSIONS Our results suggest that variation in Lmf1 expression is a posttranslational determinant of LPL activity.
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Affiliation(s)
- Maryam Hosseini
- Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
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Péterfy M. Lipase maturation factor 1: a lipase chaperone involved in lipid metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1821:790-4. [PMID: 22063272 DOI: 10.1016/j.bbalip.2011.10.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 10/03/2011] [Accepted: 10/04/2011] [Indexed: 10/16/2022]
Abstract
Mutations in lipase maturation factor 1 (LMF1) are associated with severe hypertriglyceridemia in mice and human subjects. The underlying cause is impaired lipid clearance due to lipase deficiency. LMF1 is a chaperone of the endoplasmic reticulum (ER) and it is critically required for the post-translational activation of three vascular lipases: lipoprotein lipase (LPL), hepatic lipase (HL) and endothelial lipase (EL). As LMF1 is only required for the maturation of homodimeric, but not monomeric, lipases, it is likely involved in the assembly of inactive lipase subunits into active enzymes and/or the stabilization of active dimers. Herein, we provide an overview of current understanding of LMF1 function and propose that it may play a regulatory role in lipase activation and lipid metabolism. Further studies will be required to test this hypothesis and elucidate the full spectrum of phenotypes in combined lipase deficiency. This article is part of a Special Issue entitled Triglyceride Metabolism and Disease.
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Affiliation(s)
- Miklós Péterfy
- Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States.
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Clemente-Postigo M, Queipo-Ortuño MI, Fernandez-Garcia D, Gomez-Huelgas R, Tinahones FJ, Cardona F. Adipose tissue gene expression of factors related to lipid processing in obesity. PLoS One 2011; 6:e24783. [PMID: 21966368 PMCID: PMC3178563 DOI: 10.1371/journal.pone.0024783] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 08/17/2011] [Indexed: 12/03/2022] Open
Abstract
Background Adipose tissue lipid storage and processing capacity can be a key factor for obesity-related metabolic disorders such as insulin resistance and diabetes. Lipid uptake is the first step to adipose tissue lipid storage. The aim of this study was to analyze the gene expression of factors involved in lipid uptake and processing in subcutaneous (SAT) and visceral (VAT) adipose tissue according to body mass index (BMI) and the degree of insulin resistance (IR). Methods and Principal Findings VLDL receptor (VLDLR), lipoprotein lipase (LPL), acylation stimulating protein (ASP), LDL receptor-related protein 1 (LRP1) and fatty acid binding protein 4 (FABP4) gene expression was measured in VAT and SAT from 28 morbidly obese patients with Type 2 Diabetes Mellitus (T2DM) or high IR, 10 morbidly obese patients with low IR, 10 obese patients with low IR and 12 lean healthy controls. LPL, FABP4, LRP1 and ASP expression in VAT was higher in lean controls. In SAT, LPL and FABP4 expression were also higher in lean controls. BMI, plasma insulin levels and HOMA-IR correlated negatively with LPL expression in both VAT and SAT as well as with FABP4 expression in VAT. FABP4 gene expression in SAT correlated inversely with BMI and HOMA-IR. However, multiple regression analysis showed that BMI was the main variable contributing to LPL and FABP4 gene expression in both VAT and SAT. Conclusions Morbidly obese patients have a lower gene expression of factors related with lipid uptake and processing in comparison with healthy lean persons.
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Affiliation(s)
- Mercedes Clemente-Postigo
- Laboratorio de Investigaciones Biomédicas del Hospital Virgen de la Victoria, Málaga (Fundación IMABIS), Spain
| | - Maria Isabel Queipo-Ortuño
- Laboratorio de Investigaciones Biomédicas del Hospital Virgen de la Victoria, Málaga (Fundación IMABIS), Spain
- CIBER Fisiopatología de la Obesidad y la Nutrición, Spain
| | - Diego Fernandez-Garcia
- CIBER Fisiopatología de la Obesidad y la Nutrición, Spain
- Servicio Endocrinología y Nutrición del Hospital Universitario Virgen de la Victoria, Málaga, Spain
| | - Ricardo Gomez-Huelgas
- CIBER Fisiopatología de la Obesidad y la Nutrición, Spain
- Servicio de Medicina Interna del Hospital Regional Carlos Haya, Spain
| | - Francisco J. Tinahones
- CIBER Fisiopatología de la Obesidad y la Nutrición, Spain
- Servicio Endocrinología y Nutrición del Hospital Universitario Virgen de la Victoria, Málaga, Spain
| | - Fernando Cardona
- Laboratorio de Investigaciones Biomédicas del Hospital Virgen de la Victoria, Málaga (Fundación IMABIS), Spain
- CIBER Fisiopatología de la Obesidad y la Nutrición, Spain
- * E-mail:
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14
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Su Z, Niu J, Xiao Y, Ping Q, Sun M, Huang A, You W, Sang X, Yuan D. Effect of octreotide-polyethylene glycol(100) monostearate modification on the pharmacokinetics and cellular uptake of nanostructured lipid carrier loaded with hydroxycamptothecine. Mol Pharm 2011; 8:1641-51. [PMID: 21770405 DOI: 10.1021/mp100463n] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A new conjugate, octreotide-polyethylene glycol(100) monostearate (OPMS), was developed for the enhancement of targeting delivery of hydroxycamptothecine (HCPT) loaded in nanostructured lipid carrier (NLC). 2 × 10(-3) and 5 × 10(-3) mmol of OPMS were respectively used to modify NLC so that the targeted nanocarriers with low and high ligand density were obtained. For comparison, the pegylated NLCs without octreotide were prepared by adding equal molar amounts of polyethylene glycol(100) monostearate (PGMS). The relation between the modification levels and properties of various NLCs were studied in vivo and in vitro. At a high modification level, a slower release rate of HCPT and the more stable nanocarriers was achieved. At the same time, the fixed aqueous layer thickness (FALT) and average surface density of PEG chains (SD(PEG)) was increased, but the distance (D) between two neighboring PEG grafting sites became narrower. The in vivo pharmacokinetic study in healthy rat indicated that the modified NLCs had a longer circulation than NLC (P < 0.05) due to pegylation effect and OPMS modified NLCs had larger MRT and AUC(0-t) than that of PGMS modified NLCs at the same modification level. Furthermore, the florescence microscopy observation also showed the targeting effect of octreotide modification on somatostatin receptors (SSTRs) of tumor cell (SMMC-7721). The uptake of SMMC-7721 was much more than that of normal liver cell (L02) for OPMS modified NLC, and the highest uptake was observed for 5 × 10(-3) mmol of OPMS modified one. No obvious difference was found among the L02 uptake of OPMS modified NLCs and NLC, but their uptake was higher than that of PGMS modified NLCs. All the results indicated that the OPMS highly modified NLCs would improve the effect of antitumor therapy by inhibiting the degradation, evading RES and enhancing the drug uptake of tumor cells.
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Affiliation(s)
- Zhigui Su
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China
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15
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van Hoek M, van Herpt TW, Dehghan A, Hofman A, Lieverse AG, van Duijn CM, Witteman JCM, Sijbrands EJG. Association of an APOC3 promoter variant with type 2 diabetes risk and need for insulin treatment in lean persons. Diabetologia 2011; 54:1360-7. [PMID: 21373834 PMCID: PMC3088807 DOI: 10.1007/s00125-011-2092-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Accepted: 01/25/2011] [Indexed: 12/02/2022]
Abstract
AIMS/HYPOTHESIS An APOC3 promoter haplotype has been previously associated with type 1 diabetes. In this population-based study, we investigated whether APOC3 polymorphisms increase type 2 diabetes risk and need for insulin treatment in lean participants. METHODS In the Rotterdam Study, a population-based prospective cohort (n = 7,983), Cox and logistic regression models were used to analyse the associations and interactive effects of APOC3 promoter variants (-482C > T, -455T > C) and BMI on type 2 diabetes risk and insulin treatment. Analyses were followed by replication in an independent case-control sample (1,817 cases, 2,292 controls) and meta-analysis. RESULTS In lean participants, the -482T allele was associated with increased risk of prevalent and incident type 2 diabetes: OR -482CT 1.47 (95% CI 1.13-1.92), -482TT 1.40 (95% CI 0.83-2.35), p = 0.009 for trend; HR -482CT 1.35 (95% CI 0.96-1.89), -482TT 1.68 (95% CI 0.91-3.1), p = 0.03 for trend, respectively. These results were confirmed by replication. Meta-analysis was highly significant (-482T meta-analysis p = 1.1 × 10(-4)). A borderline significant interaction was observed for insulin use among participants with type 2 diabetes (-482CT*BMI p = 0.06, -455TC*BMI p = 0.02). CONCLUSIONS/INTERPRETATION At a population-based level, the influence of APOC3 promoter variants on type 2 diabetes risk varies with the level of adiposity. Lean carriers of the -482T allele had increased type 2 diabetes risk, while such an effect was not observed in overweight participants. Conversely, in overweight participants the -455C allele seemed protective against type 2 diabetes. The interaction of the variants with need for insulin treatment may indicate beta cell involvement in lean participants. Our findings suggest overlap in the genetic backgrounds of type 1 diabetes and type 2 diabetes in lean patients.
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Affiliation(s)
- M. van Hoek
- Department of Internal Medicine, Erasmus Medical Center, PO Box 2040, 3000 CA Rotterdam, the Netherlands
- Department of Epidemiology and Biostatistics, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - T. W. van Herpt
- Department of Internal Medicine, Erasmus Medical Center, PO Box 2040, 3000 CA Rotterdam, the Netherlands
- Department of Internal Medicine, Maxima Medical Center, Eindhoven, the Netherlands
| | - A. Dehghan
- Department of Epidemiology and Biostatistics, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - A. Hofman
- Department of Epidemiology and Biostatistics, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - A. G. Lieverse
- Department of Internal Medicine, Maxima Medical Center, Eindhoven, the Netherlands
| | - C. M. van Duijn
- Department of Epidemiology and Biostatistics, Erasmus University Medical Center, Rotterdam, the Netherlands
- Department of Clinical Genetics, Genetic Epidemiology Unit, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - J. C. M. Witteman
- Department of Epidemiology and Biostatistics, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - E. J. G. Sijbrands
- Department of Internal Medicine, Erasmus Medical Center, PO Box 2040, 3000 CA Rotterdam, the Netherlands
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16
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Studies on the lipase induced degradation of lipid based drug delivery systems. J Control Release 2009; 140:27-33. [DOI: 10.1016/j.jconrel.2009.07.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Revised: 06/28/2009] [Accepted: 07/06/2009] [Indexed: 11/18/2022]
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17
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Mansouri M, Sevov M, Fahlgren E, Tobin G, Jondal M, Osorio L, Roos G, Olivecrona G, Rosenquist R. Lipoprotein lipase is differentially expressed in prognostic subsets of chronic lymphocytic leukemia but displays invariably low catalytical activity. Leuk Res 2009; 34:301-6. [PMID: 19709746 DOI: 10.1016/j.leukres.2009.07.032] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Revised: 06/18/2009] [Accepted: 07/22/2009] [Indexed: 11/29/2022]
Abstract
Lipoprotein lipase (LPL) expression has been shown to correlate with IGHV mutational status and to predict outcome in chronic lymphocytic leukemia (CLL). We here investigated the prognostic impact of LPL expression in relation to other prognostic markers including IGHV3-21 usage in 140 CLL patients. Additionally, we studied the catalytic activity of LPL in CLL cells. A significant difference in LPL mRNA expression was detected in IGHV unmutated compared to mutated CLL patients (p<0.001). However, the poor-prognostic mutated/stereotyped IGHV3-21 patients did not differ from other mutated CLL cases. Clinical outcome was significantly different in CLL cases with high versus low LPL expression (p<0.001), and LPL expression exceeded mutation status/IGHV3-21 usage as an independent prognostic marker. Finally, LPL protein expression correlated significantly with mRNA expression and was higher in IGHV unmutated versus mutated CLL (p=0.018), although the majority of synthesized protein was catalytically inactive indicating a non-catalytical function in CLL.
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Affiliation(s)
- Mahmoud Mansouri
- Department of Genetics and Pathology, Uppsala University, Uppsala, Sweden.
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18
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Abstract
Lipoprotein lipase (LPL) is a multifunctional enzyme produced by many tissues, including adipose tissue, cardiac and skeletal muscle, islets, and macrophages. LPL is the rate-limiting enzyme for the hydrolysis of the triglyceride (TG) core of circulating TG-rich lipoproteins, chylomicrons, and very low-density lipoproteins (VLDL). LPL-catalyzed reaction products, fatty acids, and monoacylglycerol are in part taken up by the tissues locally and processed differentially; e.g., they are stored as neutral lipids in adipose tissue, oxidized, or stored in skeletal and cardiac muscle or as cholesteryl ester and TG in macrophages. LPL is regulated at transcriptional, posttranscriptional, and posttranslational levels in a tissue-specific manner. Nutrient states and hormonal levels all have divergent effects on the regulation of LPL, and a variety of proteins that interact with LPL to regulate its tissue-specific activity have also been identified. To examine this divergent regulation further, transgenic and knockout murine models of tissue-specific LPL expression have been developed. Mice with overexpression of LPL in skeletal muscle accumulate TG in muscle, develop insulin resistance, are protected from excessive weight gain, and increase their metabolic rate in the cold. Mice with LPL deletion in skeletal muscle have reduced TG accumulation and increased insulin action on glucose transport in muscle. Ultimately, this leads to increased lipid partitioning to other tissues, insulin resistance, and obesity. Mice with LPL deletion in the heart develop hypertriglyceridemia and cardiac dysfunction. The fact that the heart depends increasingly on glucose implies that free fatty acids are not a sufficient fuel for optimal cardiac function. Overall, LPL is a fascinating enzyme that contributes in a pronounced way to normal lipoprotein metabolism, tissue-specific substrate delivery and utilization, and the many aspects of obesity and other metabolic disorders that relate to energy balance, insulin action, and body weight regulation.
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Affiliation(s)
- Hong Wang
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado 80045, USA
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19
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van der Ham RLM, Alizadeh Dehnavi R, Berbée JFP, Putter H, de Roos A, Romijn JA, Rensen PCN, Tamsma JT. Plasma apolipoprotein CI and CIII levels are associated with increased plasma triglyceride levels and decreased fat mass in men with the metabolic syndrome. Diabetes Care 2009; 32:184-6. [PMID: 18835943 PMCID: PMC2606811 DOI: 10.2337/dc08-1330] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To determine whether, in accordance with observations in mouse models, high concentrations of the lipoprotein lipase inhibitors apolipoprotein (Apo) CI and ApoCIII are associated with increased triglyceride concentrations and decreased fat mass in men with the metabolic syndrome. RESEARCH DESIGN AND METHODS Plasma ApoCI, ApoCIII, and triglyceride concentrations were measured in the postabsorptive state in 98 men with the metabolic syndrome. Subcutaneous and visceral fat areas were measured by 3T-magnetic resonance imaging. RESULTS Triglyceride concentrations were 49% higher, and the average visceral fat area was 26% lower (both P < 0.001), in subjects with high ApoCI and ApoCIII compared with low ApoCI and ApoCIII. Subjects with either high ApoCI or ApoCIII had 16% (P < 0.05) and 18% (P < 0.01) decreased visceral fat area, respectively. CONCLUSIONS High concentrations of ApoCI and ApoCIII are associated with increased triglycerides and decreased visceral fat mass in men with the metabolic syndrome. These findings translate mouse studies into human pathophysiology.
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Affiliation(s)
- Rachel L M van der Ham
- Section of Vascular Medicine, Department of Endocrinology and Internal Medicine, Leiden University Medical Center, Leiden, the Netherlands.
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Belaid-Choucair Z, Lepelletier Y, Poncin G, Thiry A, Humblet C, Maachi M, Beaulieu A, Schneider E, Briquet A, Mineur P, Lambert C, Mendes-Da-Cruz D, Ahui ML, Asnafi V, Dy M, Boniver J, Nusgens BV, Hermine O, Defresne MP. Human bone marrow adipocytes block granulopoiesis through neuropilin-1-induced granulocyte colony-stimulating factor inhibition. Stem Cells 2008; 26:1556-64. [PMID: 18388301 DOI: 10.1634/stemcells.2008-0068] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Adipocytes are part of hematopoietic microenvironment, even though up to now in humans, their role in hematopoiesis is still questioned. We have previously shown that accumulation of fat cells in femoral bone marrow (BM) coincides with increased expression of neuropilin-1 (NP-1), while it is weakly expressed in hematopoietic iliac crest BM. Starting from this observation, we postulated that adipocytes might exert a negative effect on hematopoiesis mediated through NP-1. To test this hypothesis, we set up BM adipocytes differentiated into fibroblast-like fat cells (FLFC), which share the major characteristics of primitive unilocular fat cells, as an experimental model. As expected, FLFCs constitutively produced macrophage colony stimulating factor and induced CD34(+) differentiation into macrophages independently of cell-to-cell contact. By contrast, granulopoiesis was hampered by cell-to-cell contact but could be restored in transwell culture conditions, together with granulocyte colony stimulating factor production. Both functions were also recovered when FLFCs cultured in contact with CD34(+) cells were treated with an antibody neutralizing NP-1, which proved its critical implication in contact inhibition. An inflammatory cytokine such as interleukin-1 beta or dexamethasone modulates FLFC properties to restore granulopoiesis. Our data provide the first evidence that primary adipocytes exert regulatory functions during hematopoiesis that might be implicated in some pathological processes. Disclosure of potential conflicts of interest is found at the end of this article.
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Affiliation(s)
- Zakia Belaid-Choucair
- Department of Cytology and Histology, Groupe Interdisciplinaire de Génoprotéomique Appliquée-Recherche, University of Liege, Liège, Belgium.
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21
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Abstract
Lipoprotein lipase (LPL) activity is necessary for adipocytes to take up triglycerides from the circulation, and regional differences in LPL activity could help determine regional fat storage. LPL activity has been reported to increase as a function of fat cell size, but this issue has not been extensively evaluated in different depots comparing sexes. Our objective was to determine whether sex alters the relationship between LPL activity and fat cell size. Subcutaneous adipose tissue biopsies were taken from the abdomen and thigh after an overnight fast and 1 h after a meal in 65 females (BMI 25.4 +/- 0.8, means +/- SE) and 41 males (BMI 23.7 +/- 0.3); gluteal adipose samples were obtained in 47 of the females and 27 of the males. Fat cell size was greater in females than males in thigh (P < 0.005) and gluteal (P < 0.05) regions but not in the abdomen. There was a relationship between fasting LPL activity/fat cell and fat cell size in females (abdomen r2 = 0.52, P < 0.0001; gluteal r2 = 0.23, P < 0.005; thigh r2 = 0.19, P < 0.005). In males, this relationship was seen only in the abdomen (r2 = 0.51, P < 0.0001) and thigh (r2 = 0.17, P < 0.05). Males and females had a significantly different relationship in the thigh only in the fasted state. Similar results were found in the fed state, although the strength of the relationship decreased in the abdominal regions for females only. This suggests fundamental differences in the regulation of triglyceride uptake between males and females and adipose regions.
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Affiliation(s)
- Susanne B Votruba
- Endocrine Research Unit, 200 1st St. SW, Rm. 5-194 Joseph, Rochester, MN 55905, USA
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22
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Abstract
Visceral obesity is an independent risk factor for the development of cardiovascular diseases and type 2 diabetes. This is likely to be due to biological characteristics of visceral tissue, which are different from those of subcutaneous adipose tissue in terms of decreased insulin sensitivity and increased lipolytic activity. In addition, the anatomical site of visceral fat could be one potential reason for the increased cardio-metabolic risk associated with visceral obesity. Visceral adipose tissue drains into the portal vein and therefore the liver is exposed to the undiluted metabolites and adipokines released from visceral fat. There are profound differences between visceral and subcutaneous adipocytes in the metabolism, expression of specific receptors and secretion of a specific adipokine pattern, which could contribute to the adverse consequences of visceral obesity.
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Affiliation(s)
- N Klöting
- Medizinische Klinik und Poliklinik III, Universität Leipzig, 04103 Leipzig, Deutschland
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