1
|
Jiang S, Ren Z, Yang Y, Liu Q, Zhou S, Xiao Y. The GPIHBP1-LPL complex and its role in plasma triglyceride metabolism: Insights into chylomicronemia. Biomed Pharmacother 2023; 169:115874. [PMID: 37951027 DOI: 10.1016/j.biopha.2023.115874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/06/2023] [Accepted: 11/07/2023] [Indexed: 11/13/2023] Open
Abstract
GPIHBP1 is a protein found in the endothelial cells of capillaries that is anchored by glycosylphosphatidylinositol and binds to high-density lipoproteins. GPIHBP1 attaches to lipoprotein lipase (LPL), subsequently carrying the enzyme and anchoring it to the capillary lumen. Enabling lipid metabolism is essential for the marginalization of lipoproteins alongside capillaries. Studies underscore the significance of GPIHBP1 in transporting, stabilizing, and aiding in the marginalization of LPL. The intricate interplay between GPIHBP1 and LPL has provided novel insights into chylomicronemia in recent years. Mutations hindering the formation or reducing the efficiency of the GPIHBP1-LPL complex are central to the onset of chylomicronemia. This review delves into the structural nuances of the GPIHBP1-LPL interaction, the consequences of mutations in the complex leading to chylomicronemia, and cutting-edge advancements in chylomicronemia treatment.
Collapse
Affiliation(s)
- Shali Jiang
- Department of Cardiovascular Medicine, Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, PR China; Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Zhuoqun Ren
- Department of Cardiovascular Medicine, Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, PR China; Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Yutao Yang
- Department of Cardiovascular Medicine, Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, PR China; Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Qiming Liu
- Department of Cardiovascular Medicine, Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, PR China
| | - Shenghua Zhou
- Department of Cardiovascular Medicine, Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, PR China
| | - Yichao Xiao
- Department of Cardiovascular Medicine, Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, PR China.
| |
Collapse
|
2
|
Kurooka N, Eguchi J, Wada J. Role of glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 in hypertriglyceridemia and diabetes. J Diabetes Investig 2023; 14:1148-1156. [PMID: 37448184 PMCID: PMC10512915 DOI: 10.1111/jdi.14056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 06/25/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
In diabetes, the impairment of insulin secretion and insulin resistance contribute to hypertriglyceridemia, as the enzymatic activity of lipoprotein lipase (LPL) depends on insulin action. The transport of LPL to endothelial cells and its enzymatic activity are maintained by the formation of lipolytic complex depending on the multiple positive (glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 [GPIHBP1], apolipoprotein C-II [APOC2], APOA5, heparan sulfate proteoglycan [HSPG], lipase maturation factor 1 [LFM1] and sel-1 suppressor of lin-12-like [SEL1L]) and negative regulators (APOC1, APOC3, angiopoietin-like proteins [ANGPTL]3, ANGPTL4 and ANGPTL8). Among the regulators, GPIHBP1 is a crucial molecule for the translocation of LPL from parenchymal cells to the luminal surface of capillary endothelial cells, and maintenance of lipolytic activity; that is, hydrolyzation of triglyceride into free fatty acids and monoglyceride, and conversion from chylomicron to chylomicron remnant in the exogenous pathway and from very low-density lipoprotein to low-density lipoprotein in the endogenous pathway. The null mutation of GPIHBP1 causes severe hypertriglyceridemia and pancreatitis, and GPIGBP1 autoantibody syndrome also causes severe hypertriglyceridemia and recurrent episodes of acute pancreatitis. In patients with type 2 diabetes, the elevated serum triglyceride levels negatively correlate with circulating LPL levels, and positively with circulating APOC1, APOC3, ANGPTL3, ANGPTL4 and ANGPTL8 levels. In contrast, circulating GPIHBP1 levels are not altered in type 2 diabetes patients with higher serum triglyceride levels, whereas they are elevated in type 2 diabetes patients with diabetic retinopathy and nephropathy. The circulating regulators of lipolytic complex might be new biomarkers for lipid and glucose metabolism, and diabetic vascular complications.
Collapse
Affiliation(s)
- Naoko Kurooka
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Faculty of Medicine, Dentistry and Pharmaceutical SciencesOkayama UniversityOkayamaJapan
| | - Jun Eguchi
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Faculty of Medicine, Dentistry and Pharmaceutical SciencesOkayama UniversityOkayamaJapan
| | - Jun Wada
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Faculty of Medicine, Dentistry and Pharmaceutical SciencesOkayama UniversityOkayamaJapan
| |
Collapse
|
3
|
Fan R, An X, Wang Y, Zhang J, Liu S, Bai J, Li J, Lin Q, Xie Y, Xia Y, Liao J. Severe hypertriglyceridemia caused by Gpihbp1 deficiency facilitates vascular remodeling through increasing endothelial activation and oxidative stress. Biochim Biophys Acta Mol Cell Biol Lipids 2023; 1868:159330. [PMID: 37172802 DOI: 10.1016/j.bbalip.2023.159330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 05/01/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023]
Abstract
Hypertriglyceridemia (HTG) is an independent risk factor for atherosclerosis. However, its impact on non-atherosclerotic cardiovascular diseases remains largely unknown. Glycosylphosphatidylinositol anchored high-density lipoprotein binding protein 1 (GPIHBP1) is essential for the hydrolysis of circulating triglycerides and loss of functional GPIHBP1 causes severe HTG. In this study, we used Gpihbp1 knockout (GKO) mice to investigate the potential effects of HTG on non-atherosclerotic vascular remodeling. We compared the aortic morphology and gene expressions between three-month-old and ten-month-old GKO mice and their age-matched wild-type controls. We also conducted similar comparisons between GKO mice and wild-type controls in an angiotensin II (AngII)-induced vascular remodeling model. Our data showed that the intima-media wall of ten-month-old GKO mice but not three-month-olds was significantly thickened compared to wild-type controls. Moreover, ten-month-old GKO mice but not three-month-olds had increased aortic macrophage infiltration and perivascular fibrosis, along with increased endothelial activation and oxidative stress. Similarly, the AngII-induced vascular remodeling, as well as endothelial activation and oxidative stress, were also exacerbated in the GKO mice compared to wild-type controls. In conclusion, we demonstrated that severe HTG caused by Gpihbp1 deficiency could facilitate the onset and progression of non-atherosclerotic vascular remodeling through endothelial activation and oxidative stress in mice.
Collapse
Affiliation(s)
- Rui Fan
- Institute of Cardiovascular Diseases, First Affiliated Hospital of Dalian Medical University, Dalian 116011, PR China
| | - Xiangbo An
- Department of Interventional Therapy, First Affiliated Hospital of Dalian Medical University, Dalian 116011, PR China
| | - Yao Wang
- Institute of Cardiovascular Diseases, First Affiliated Hospital of Dalian Medical University, Dalian 116011, PR China
| | - Jinjin Zhang
- Institute of Cardiovascular Diseases, First Affiliated Hospital of Dalian Medical University, Dalian 116011, PR China
| | - Shuang Liu
- College of Basic Medical Sciences, Dalian Medical University, Dalian 116004, PR China
| | - Jie Bai
- Department of Nutrition and Food Hygiene, School of Public Health, Dalian Medical University, Dalian 116004, PR China
| | - Jiatian Li
- Institute of Cardiovascular Diseases, First Affiliated Hospital of Dalian Medical University, Dalian 116011, PR China
| | - Qiuyue Lin
- Institute of Cardiovascular Diseases, First Affiliated Hospital of Dalian Medical University, Dalian 116011, PR China
| | - Yunpeng Xie
- Institute of Cardiovascular Diseases, First Affiliated Hospital of Dalian Medical University, Dalian 116011, PR China
| | - Yunlong Xia
- Institute of Cardiovascular Diseases, First Affiliated Hospital of Dalian Medical University, Dalian 116011, PR China.
| | - Jiawei Liao
- Institute of Cardiovascular Diseases, First Affiliated Hospital of Dalian Medical University, Dalian 116011, PR China.
| |
Collapse
|
4
|
Abstract
Despite the success of LDL-lowering drugs in reducing cardiovascular disease (CVD), there remains a large burden of residual disease due in part to persistent dyslipidemia characterized by elevated levels of triglyceride-rich lipoproteins (TRLs) and reduced levels of HDL. This form of dyslipidemia is increasing globally as a result of the rising prevalence of obesity and metabolic syndrome. Accumulating evidence suggests that impaired hepatic clearance of cholesterol-rich TRL remnants leads to their accumulation in arteries, promoting foam cell formation and inflammation. Low levels of HDL may associate with reduced cholesterol efflux from foam cells, aggravating atherosclerosis. While fibrates and fish oils reduce TRL, they have not been uniformly successful in reducing CVD, and there is a large unmet need for new approaches to reduce remnants and CVD. Rare genetic variants that lower triglyceride levels via activation of lipolysis and associate with reduced CVD suggest new approaches to treating dyslipidemia. Apolipoprotein C3 (APOC3) and angiopoietin-like 3 (ANGPTL3) have emerged as targets for inhibition by antibody, antisense, or RNAi approaches. Inhibition of either molecule lowers TRL but respectively raises or lowers HDL levels. Large clinical trials of such agents in patients with high CVD risk and elevated levels of TRL will be required to demonstrate efficacy of these approaches.
Collapse
Affiliation(s)
- Alan R Tall
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, New York, USA
| | - David G Thomas
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, New York, USA
| | - Ainara G Gonzalez-Cabodevilla
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University Grossman School of Medicine, New York, New York, USA
| | - Ira J Goldberg
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University Grossman School of Medicine, New York, New York, USA
| |
Collapse
|
5
|
Abstract
Despite the decades-old knowledge that diabetes mellitus is a major risk factor for cardiovascular disease, the reasons for this association are only partially understood. While this association is true for both type 1 and type 2 diabetes, different pathophysiological processes may be responsible. Lipids and other risk factors are indeed important, whereas the role of glucose is less clear. This lack of clarity stems from clinical trials that do not unambiguously show that intensive glycemic control reduces cardiovascular events. Animal models have provided mechanisms that link diabetes to increased atherosclerosis, and evidence consistent with the importance of factors beyond hyperglycemia has emerged. We review clinical, pathological, and animal studies exploring the pathogenesis of atherosclerosis in humans living with diabetes and in mouse models of diabetes. An increased effort to identify risk factors beyond glucose is now needed to prevent the increased cardiovascular disease risk associated with diabetes.
Collapse
Affiliation(s)
- Robert H Eckel
- Divisions of Endocrinology, Metabolism and Diabetes, and Cardiology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA.
| | - Karin E Bornfeldt
- Department of Medicine, Division of Metabolism, Endocrinology and Nutrition, and Department of Laboratory Medicine and Pathology, University of Washington Medicine Diabetes Institute, University of Washington, Seattle, WA, USA
| | - Ira J Goldberg
- Division of Endocrinology, Diabetes and Metabolism, NYU Grossman School of Medicine, New York, NY, USA
| |
Collapse
|
6
|
Shang R, Rodrigues B. Lipoprotein Lipase and Its Delivery of Fatty Acids to the Heart. Biomolecules 2021; 11:biom11071016. [PMID: 34356640 PMCID: PMC8301904 DOI: 10.3390/biom11071016] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 07/08/2021] [Accepted: 07/08/2021] [Indexed: 02/05/2023] Open
Abstract
Ninety percent of plasma fatty acids (FAs) are contained within lipoprotein-triglyceride, and lipoprotein lipase (LPL) is robustly expressed in the heart. Hence, LPL-mediated lipolysis of lipoproteins is suggested to be a key source of FAs for cardiac use. Lipoprotein clearance by LPL occurs at the apical surface of the endothelial cell lining of the coronary lumen. In the heart, the majority of LPL is produced in cardiomyocytes and subsequently is translocated to the apical luminal surface. Here, vascular LPL hydrolyzes lipoprotein-triglyceride to provide the heart with FAs for ATP generation. This article presents an overview of cardiac LPL, explains how the enzyme works, describes key molecules that regulate its activity and outlines how changes in LPL are brought about by physiological and pathological states such as fasting and diabetes, respectively.
Collapse
|
7
|
Basu D, Bornfeldt KE. Hypertriglyceridemia and Atherosclerosis: Using Human Research to Guide Mechanistic Studies in Animal Models. Front Endocrinol (Lausanne) 2020; 11:504. [PMID: 32849290 PMCID: PMC7423973 DOI: 10.3389/fendo.2020.00504] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 06/23/2020] [Indexed: 12/18/2022] Open
Abstract
Human studies support a strong association between hypertriglyceridemia and atherosclerotic cardiovascular disease (CVD). However, whether a causal relationship exists between hypertriglyceridemia and increased CVD risk is still unclear. One plausible explanation for the difficulty establishing a clear causal role for hypertriglyceridemia in CVD risk is that lipolysis products of triglyceride-rich lipoproteins (TRLs), rather than the TRLs themselves, are the likely mediators of increased CVD risk. This hypothesis is supported by studies of rare mutations in humans resulting in impaired clearance of such lipolysis products (remnant lipoprotein particles; RLPs). Several animal models of hypertriglyceridemia support this hypothesis and have provided additional mechanistic understanding. Mice deficient in lipoprotein lipase (LPL), the major vascular enzyme responsible for TRL lipolysis and generation of RLPs, or its endothelial anchor GPIHBP1, are severely hypertriglyceridemic but develop only minimal atherosclerosis as compared with animal models deficient in apolipoprotein (APO) E, which is required to clear TRLs and RLPs. Likewise, animal models convincingly show that increased clearance of TRLs and RLPs by LPL activation (achieved by inhibition of APOC3, ANGPTL3, or ANGPTL4 action, or increased APOA5) results in protection from atherosclerosis. Mechanistic studies suggest that RLPs are more atherogenic than large TRLs because they more readily enter the artery wall, and because they are enriched in cholesterol relative to triglycerides, which promotes pro-atherogenic effects in lesional cells. Other mechanistic studies show that hepatic receptors (LDLR and LRP1) and APOE are critical for RLP clearance. Thus, studies in animal models have provided additional mechanistic insight and generally agree with the hypothesis that RLPs derived from TRLs are highly atherogenic whereas hypertriglyceridemia due to accumulation of very large TRLs in plasma is not markedly atherogenic in the absence of TRL lipolysis products.
Collapse
Affiliation(s)
- Debapriya Basu
- Division of Endocrinology, Diabetes and Metabolism, New York University School of Medicine, New York, NY, United States
| | - Karin E. Bornfeldt
- Department of Medicine, University of Washington Medicine Diabetes Institute, University of Washington School of Medicine, Seattle, WA, United States
- Department of Pathology, University of Washington Medicine Diabetes Institute, University of Washington School of Medicine, Seattle, WA, United States
- *Correspondence: Karin E. Bornfeldt
| |
Collapse
|
8
|
Young SG, Fong LG, Beigneux AP, Allan CM, He C, Jiang H, Nakajima K, Meiyappan M, Birrane G, Ploug M. GPIHBP1 and Lipoprotein Lipase, Partners in Plasma Triglyceride Metabolism. Cell Metab 2019; 30:51-65. [PMID: 31269429 PMCID: PMC6662658 DOI: 10.1016/j.cmet.2019.05.023] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Lipoprotein lipase (LPL), identified in the 1950s, has been studied intensively by biochemists, physiologists, and clinical investigators. These efforts uncovered a central role for LPL in plasma triglyceride metabolism and identified LPL mutations as a cause of hypertriglyceridemia. By the 1990s, with an outline for plasma triglyceride metabolism established, interest in triglyceride metabolism waned. In recent years, however, interest in plasma triglyceride metabolism has awakened, in part because of the discovery of new molecules governing triglyceride metabolism. One such protein-and the focus of this review-is GPIHBP1, a protein of capillary endothelial cells. GPIHBP1 is LPL's essential partner: it binds LPL and transports it to the capillary lumen; it is essential for lipoprotein margination along capillaries, allowing lipolysis to proceed; and it preserves LPL's structure and activity. Recently, GPIHBP1 was the key to solving the structure of LPL. These developments have transformed the models for intravascular triglyceride metabolism.
Collapse
Affiliation(s)
- Stephen G Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Loren G Fong
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Anne P Beigneux
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Christopher M Allan
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Cuiwen He
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Haibo Jiang
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; School of Molecular Sciences, University of Western Australia, Crawley 6009, Australia
| | - Katsuyuki Nakajima
- Department of Clinical Laboratory Medicine, Gunma University Graduate School of Department of Medicine, Maebashi, Gunma 371-0805, Japan
| | - Muthuraman Meiyappan
- Discovery Therapeutics, Takeda Pharmaceutical Company Ltd., Cambridge, MA 02142, USA
| | - Gabriel Birrane
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | - Michael Ploug
- Finsen Laboratory, Rigshospitalet, Copenhagen DK-2200, Denmark; Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen DK-2200, Denmark.
| |
Collapse
|
9
|
Yu B, Zhang M, Chen J, Wang L, Peng X, Zhang X, Wang H, Wang A, Zhao D, Pang D, OuYang H, Tang X. Abnormality of hepatic triglyceride metabolism in Apc Min/+ mice with colon cancer cachexia. Life Sci 2019; 227:201-211. [PMID: 31002917 DOI: 10.1016/j.lfs.2019.04.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 04/10/2019] [Accepted: 04/16/2019] [Indexed: 01/01/2023]
Abstract
AIMS Colorectal cancer syndrome has been one of the greatest concerns in the world. Although several epidemiological studies have shown that hepatic low lipoprotein lipase (LPL) mRNA expression may be associated with dyslipidemia and tumor progression, it is still not known whether the liver plays an essential role in hyperlipidemia of ApcMin/+ mice. MAIN METHODS We measured the expression of metabolic enzymes that involved fatty acid uptake, de novo lipogenesis (DNL), β-oxidation and investigated hepatic triglyceride production in the liver of wild-type and ApcMin/+ mice. KEY FINDINGS We found that hepatic fatty acid uptake and DNL decreased, but there was no significant difference in fatty acid β-oxidation. Interestingly, the production of hepatic very low-density lipoprotein-triglyceride (VLDL-TG) decreased at 20 weeks of age, but marked steatosis was observed in the livers of the ApcMin/+ mouse. To further explore hypertriglyceridemia, we assessed the function of hepatic glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 (GPIHBP1) for the first time. GPIHBP1 is governed by the transcription factor octamer-binding transcription factor-1 (Oct-1) which are involved in the nuclear factor-κB (NF-κB) signaling pathway in the liver of ApcMin/+ mice. Importantly, it was also confirmed that sn50 (100 μg/mL, an inhibitor of the NF-κB) reversed the tumor necrosis factor α (TNFα)-induced Oct-1 and GPIHBP1 reduction in HepG2 cells. SIGNIFICANCE Altogether, these findings highlighted a novel role of GPIHBP1 that might be responsible for hypertriglyceridemia in ApcMin/+ mice. Hypertriglyceridemia in these mice may be associated with their hepatic lipid metabolism development.
Collapse
Affiliation(s)
- Biao Yu
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Mingjun Zhang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Jiahuan Chen
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Lingyu Wang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Xiaohuan Peng
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Xinwei Zhang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - He Wang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Anbei Wang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Dazhong Zhao
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Daxin Pang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Hongsheng OuYang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Xiaochun Tang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China.
| |
Collapse
|
10
|
Liu X, Li J, Liao J, Wang H, Huang X, Dong Z, Shen Q, Zhang L, Wang Y, Kong W, Liu G, Huang W. Gpihbp1 deficiency accelerates atherosclerosis and plaque instability in diabetic Ldlr-/- mice. Atherosclerosis 2019; 282:100-109. [PMID: 30721842 DOI: 10.1016/j.atherosclerosis.2019.01.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 12/29/2018] [Accepted: 01/15/2019] [Indexed: 01/17/2023]
|
11
|
Liu C, Li L, Guo D, Lv Y, Zheng X, Mo Z, Xie W. Lipoprotein lipase transporter GPIHBP1 and triglyceride-rich lipoprotein metabolism. Clin Chim Acta 2018; 487:33-40. [PMID: 30218660 DOI: 10.1016/j.cca.2018.09.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 09/11/2018] [Accepted: 09/11/2018] [Indexed: 02/05/2023]
Abstract
Increased plasma triglyceride serves as an independent risk factor for cardiovascular disease (CVD). Lipoprotein lipase (LPL), which hydrolyzes circulating triglyceride, plays a crucial role in normal lipid metabolism and energy balance. Hypertriglyceridemia is possibly caused by gene mutations resulting in LPL dysfunction. There are many factors that both positively and negatively interact with LPL thereby impacting TG lipolysis. Glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1), a newly identified factor, appears essential for transporting LPL to the luminal side of the blood vessel and offering a platform for TG hydrolysis. Numerous lines of evidence indicate that GPIHBP1 exerts distinct functions and plays diverse roles in human triglyceride-rich lipoprotein (TRL) metabolism. In this review, we discuss the GPIHBP1 gene, protein, its expression and function and subsequently focus on its regulation and provide critical evidence supporting its role in TRL metabolism. Underlying mechanisms of action are highlighted, additional studies discussed and potential therapeutic targets reviewed.
Collapse
Affiliation(s)
- Chuhao Liu
- Clinical Anatomy & Reproductive Medicine Application Institute, University of South China, Hengyang 421001, Hunan, China; 2016 Class of Excellent Doctor, University of South China, Hengyang 421001, Hunan, China
| | - Liang Li
- Department of Pathophysiology, University of South China, Hengyang 421001, Hunan, China
| | - Dongming Guo
- Clinical Anatomy & Reproductive Medicine Application Institute, University of South China, Hengyang 421001, Hunan, China
| | - Yuncheng Lv
- Clinical Anatomy & Reproductive Medicine Application Institute, University of South China, Hengyang 421001, Hunan, China
| | - XiLong Zheng
- Department of Biochemistry and Molecular Biology, The Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, The University of Calgary, Health Sciences Center, 3330 Hospital Dr NW, Calgary T2N 4N1, Alberta, Canada; Key Laboratory of Molecular Targets & Clinical Pharmacology, School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou 511436, Guangdong, China
| | - Zhongcheng Mo
- Clinical Anatomy & Reproductive Medicine Application Institute, University of South China, Hengyang 421001, Hunan, China.
| | - Wei Xie
- Clinical Anatomy & Reproductive Medicine Application Institute, University of South China, Hengyang 421001, Hunan, China.
| |
Collapse
|
12
|
He C, Weston TA, Jung RS, Heizer P, Larsson M, Hu X, Allan CM, Tontonoz P, Reue K, Beigneux AP, Ploug M, Holme A, Kilburn M, Guagliardo P, Ford DA, Fong LG, Young SG, Jiang H. NanoSIMS Analysis of Intravascular Lipolysis and Lipid Movement across Capillaries and into Cardiomyocytes. Cell Metab 2018; 27:1055-1066.e3. [PMID: 29719224 PMCID: PMC5945212 DOI: 10.1016/j.cmet.2018.03.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 02/16/2018] [Accepted: 03/24/2018] [Indexed: 10/17/2022]
Abstract
The processing of triglyceride-rich lipoproteins (TRLs) in capillaries provides lipids for vital tissues, but our understanding of TRL metabolism is limited, in part because TRL processing and lipid movement have never been visualized. To investigate the movement of TRL-derived lipids in the heart, mice were given an injection of [2H]triglyceride-enriched TRLs, and the movement of 2H-labeled lipids across capillaries and into cardiomyocytes was examined by NanoSIMS. TRL processing and lipid movement in tissues were extremely rapid. Within 30 s, TRL-derived lipids appeared in the subendothelial spaces and in the lipid droplets and mitochondria of cardiomyocytes. Enrichment of 2H in capillary endothelial cells was not greater than in cardiomyocytes, implying that endothelial cells may not be a control point for lipid movement into cardiomyocytes. Remarkably, a deficiency of the putative fatty acid transport protein CD36, which is expressed highly in capillary endothelial cells, did not impede entry of TRL-derived lipids into cardiomyocytes.
Collapse
Affiliation(s)
- Cuiwen He
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Thomas A Weston
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Rachel S Jung
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Patrick Heizer
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Mikael Larsson
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Xuchen Hu
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Christopher M Allan
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Peter Tontonoz
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Karen Reue
- Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Anne P Beigneux
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Michael Ploug
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark; Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Andrea Holme
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth 6009, Australia
| | - Matthew Kilburn
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth 6009, Australia
| | - Paul Guagliardo
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth 6009, Australia
| | - David A Ford
- Department of Biochemistry and Molecular Biology, Center for Cardiovascular Research, Saint Louis University, St. Louis, MO 63104, USA
| | - Loren G Fong
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Stephen G Young
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Haibo Jiang
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth 6009, Australia.
| |
Collapse
|
13
|
Drager LF, Tavoni TM, Silva VM, Santos RD, Pedrosa RP, Bortolotto LA, Vinagre CG, Polotsky VY, Lorenzi-Filho G, Maranhao RC. Obstructive sleep apnea and effects of continuous positive airway pressure on triglyceride-rich lipoprotein metabolism. J Lipid Res 2018; 59:1027-1033. [PMID: 29628442 DOI: 10.1194/jlr.m083436] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 03/19/2018] [Indexed: 11/20/2022] Open
Abstract
This study aimed to explore lipoprotein metabolism in obstructive sleep apnea (OSA) and the effects of continuous positive airway pressure (CPAP). We studied 15 men with severe OSA [apnea-hypopnea index (AHI) ≥30 events/hour] and 12 age-, BMI-, and waist circumference-matched volunteers without OSA (AHI <5 events/hour). Carotid intima-media thickness (CIMT) was determined by a blind examiner. After 12 h fasting, a triglyceride-rich chylomicron-like emulsion, labeled with [14C]cholesteryl oleate and [3H]triolein, was injected intravenously followed by blood sample collection at preestablished times. Fractional clearance rate (FCR) of the radiolabeled lipids was estimated by compartmental analysis of radioisotope decay curves. Compared with controls, patients with OSA showed a significant delay in both cholesteryl ester FCR (0.0126 ± 0.0187 vs. 0.0015 ± 0.0025 min-1; P = 0.0313) and triglycerides FCR (0.0334 ± 0.0390 vs. 0.0051 ± 0.0074 min-1; P = 0.0001). CIMT was higher in the OSA group: 620 ± 17 vs. 725 ± 29 µm; P = 0.004. Cholesteryl ester FCRs were inversely related to total sleep time <90% (r = -0.463; P = 0.029) and CIMT (r = -0.601; P = 0.022). The triglyceride FCR was inversely correlated with AHI (r = -0.537; P = 0.04). In a subgroup of patients treated with CPAP for 3 months (n = 7), triglyceride FCR increased 5-fold (P = 0.025), but the cholesteryl ester FCR was unchanged. In conclusion, severe OSA decreased lipolysis of triglyceride-rich lipoproteins and delayed removal of remnants. CPAP treatment may be effective to restore the lipolysis rates.
Collapse
Affiliation(s)
- Luciano F Drager
- Hypertension Unit, University of Sao Paulo Medical School, São Paulo, Brazil
| | - Thauany M Tavoni
- Laboratory of Metabolism and Lipids, University of Sao Paulo Medical School, São Paulo, Brazil
| | - Vanessa M Silva
- Laboratory of Metabolism and Lipids, University of Sao Paulo Medical School, São Paulo, Brazil
| | - Raul D Santos
- Lipid Clinic, University of Sao Paulo Medical School, São Paulo, Brazil
| | - Rodrigo P Pedrosa
- Sleep and Heart Laboratory, University of Pernambuco, Recife, Brazil
| | - Luiz A Bortolotto
- Hypertension Unit, University of Sao Paulo Medical School, São Paulo, Brazil
| | - Carmen G Vinagre
- Laboratory of Metabolism and Lipids, University of Sao Paulo Medical School, São Paulo, Brazil
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Geraldo Lorenzi-Filho
- Sleep Laboratory, Pulmonary Division, Heart Institute (InCor), University of Sao Paulo Medical School, São Paulo, Brazil
| | - Raul C Maranhao
- Laboratory of Metabolism and Lipids, University of Sao Paulo Medical School, São Paulo, Brazil; Faculty of Pharmaceutical Sciences, University of Sao Paulo, São Paulo, Brazil.
| |
Collapse
|
14
|
Zafrir B, Jubran A, Hijazi R, Shapira C. Clinical features and outcomes of severe, very severe, and extreme hypertriglyceridemia in a regional health service. J Clin Lipidol 2018; 12:928-936. [PMID: 29685592 DOI: 10.1016/j.jacl.2018.03.086] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/19/2018] [Accepted: 03/27/2018] [Indexed: 12/22/2022]
Abstract
BACKGROUND Comprehensive data on severe hypertriglyceridemia (HTG) in the general population setting are limited and of importance due to the increase in metabolic risk factors and novel therapies under development. OBJECTIVE To investigate contributing causes and outcomes of severe to extreme HTG. METHODS Regional database retrospectively analyzed for subjects with severe HTG. Adverse outcomes were investigated in correlation to HTG severity, with follow-up initiating at first documentation of HTG > 1000 mg/dL. RESULTS A total of 3091 subjects with severe (peak triglycerides 1000-1999 mg/dL; n = 2590), very severe (2000-2999 mg/dL; n = 369), and extreme (≥3000 mg/dL; n = 132) HTG were identified. Mean age was 48 ± 12 years; 73% males. Obesity (48%) and diabetes (62%) were main contributing factors. During follow-up (median 101 months), 4.7% subjects had pancreatitis, 4.7% myocardial infarction, and 6% stroke. Compared with severe HTG, the multivariate-adjusted hazard ratio for pancreatitis was 3.22 (95% confidence interval 2.21-4.70) for individuals with very severe HTG and 5.55 (3.53-8.71) for those with extreme HTG, P < .0001. In contrast, the extent of HTG severity at these levels was not associated with worse cardiovascular outcomes or death. Most subjects (81%) achieved triglyceride levels <500 mg/dL, associated with lower risk for developing pancreatitis but not myocardial infarction or stroke. CONCLUSIONS Severity of HTG is closely related to cardiometabolic conditions, with a stepwise increase in the risk for pancreatitis, particularly if not attaining reduced triglyceride levels during the follow-up. In contrast, whereas mild-to-moderate HTG is a known established cardiovascular risk factor, very severe and extreme HTG may not further increase the risk for myocardial infarction, stroke, or mortality.
Collapse
Affiliation(s)
- Barak Zafrir
- Cardiovascular Medicine, Lady Davis Carmel Medical Center, Haifa and Western Galilee District, Israel; Clalit Health Services, Haifa and Western Galilee District, Israel; The Faculty of Medicine, Technion, Israel Institute of Medicine, Haifa, Israel.
| | - Ayman Jubran
- Cardiovascular Medicine, Lady Davis Carmel Medical Center, Haifa and Western Galilee District, Israel; Clalit Health Services, Haifa and Western Galilee District, Israel; The Faculty of Medicine, Technion, Israel Institute of Medicine, Haifa, Israel
| | - Rawan Hijazi
- Cardiovascular Medicine, Lady Davis Carmel Medical Center, Haifa and Western Galilee District, Israel; Clalit Health Services, Haifa and Western Galilee District, Israel; The Faculty of Medicine, Technion, Israel Institute of Medicine, Haifa, Israel
| | - Chen Shapira
- Cardiovascular Medicine, Lady Davis Carmel Medical Center, Haifa and Western Galilee District, Israel; Clalit Health Services, Haifa and Western Galilee District, Israel; The Faculty of Medicine, Technion, Israel Institute of Medicine, Haifa, Israel
| |
Collapse
|
15
|
Goldberg IJ. 2017 George Lyman Duff Memorial Lecture: Fat in the Blood, Fat in the Artery, Fat in the Heart: Triglyceride in Physiology and Disease. Arterioscler Thromb Vasc Biol 2018; 38:700-706. [PMID: 29419410 DOI: 10.1161/atvbaha.117.309666] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 01/10/2018] [Indexed: 12/31/2022]
Abstract
Cholesterol is not the only lipid that causes heart disease. Triglyceride supplies the heart and skeletal muscles with highly efficient fuel and allows for the storage of excess calories in adipose tissue. Failure to transport, acquire, and use triglyceride leads to energy deficiency and even death. However, overabundance of triglyceride can damage and impair tissues. Circulating lipoprotein-associated triglycerides are lipolyzed by lipoprotein lipase (LpL) and hepatic triglyceride lipase. We inhibited these enzymes and showed that LpL inhibition reduces high-density lipoprotein cholesterol by >50%, and hepatic triglyceride lipase inhibition shifts low-density lipoprotein to larger, more buoyant particles. Genetic variations that reduce LpL activity correlate with increased cardiovascular risk. In contrast, macrophage LpL deficiency reduces macrophage function and atherosclerosis. Therefore, muscle and macrophage LpL have opposite effects on atherosclerosis. With models of atherosclerosis regression that we used to study diabetes mellitus, we are now examining whether triglyceride-rich lipoproteins or their hydrolysis by LpL affect the biology of established plaques. Following our focus on triglyceride metabolism led us to show that heart-specific LpL hydrolysis of triglyceride allows optimal supply of fatty acids to the heart. In contrast, cardiomyocyte LpL overexpression and excess lipid uptake cause lipotoxic heart failure. We are now studying whether interrupting pathways for lipid uptake might prevent or treat some forms of heart failure.
Collapse
Affiliation(s)
- Ira J Goldberg
- From the Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, New York University School of Medicine.
| |
Collapse
|
16
|
|
17
|
Abstract
The issue of plasma triglyceride levels relative to the risk of development of cardiovascular disease, as well as overall mortality, has been actively discussed for many years. Like other cardiovascular disease risk factors, final plasma TG values have environmental influences (primarily dietary habits, physical activity, and smoking), and a genetic predisposition. Rare mutations (mainly in the lipoprotein lipase and apolipoprotein C2) along with common polymorphisms (within apolipoprotein A5, glucokinase regulatory protein, apolipoprotein B, apolipo-protein E, cAMP responsive element binding protein 3-like 3, glycosylphosphatidylinositol-anchored HDL-binding protein 1) play an important role in determining plasma TG levels.
Collapse
Affiliation(s)
- L Schwarzova
- Third Department of Internal Medicine, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
| | | | | |
Collapse
|
18
|
Fong LG, Young SG, Beigneux AP, Bensadoun A, Oberer M, Jiang H, Ploug M. GPIHBP1 and Plasma Triglyceride Metabolism. Trends Endocrinol Metab 2016; 27:455-469. [PMID: 27185325 PMCID: PMC4927088 DOI: 10.1016/j.tem.2016.04.013] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 10/21/2022]
Abstract
GPIHBP1, a GPI-anchored protein in capillary endothelial cells, is crucial for the lipolytic processing of triglyceride-rich lipoproteins (TRLs). GPIHBP1 shuttles lipoprotein lipase (LPL) to its site of action in the capillary lumen and is essential for the margination of TRLs along capillaries - such that lipolytic processing can proceed. GPIHBP1 also reduces the unfolding of the LPL catalytic domain, thereby stabilizing LPL catalytic activity. Many different GPIHBP1 mutations have been identified in patients with severe hypertriglyceridemia (chylomicronemia), the majority of which interfere with folding of the protein and abolish its capacity to bind and transport LPL. The discovery of GPIHBP1 has substantially revised our understanding of intravascular triglyceride metabolism but has also raised many new questions for future research.
Collapse
Affiliation(s)
- Loren G Fong
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
| | - Stephen G Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA; Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
| | - Anne P Beigneux
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - André Bensadoun
- Division of Nutritional Science, Cornell University, Ithaca, NY 14853, USA
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz and BioTechMed, Graz, Austria
| | - Haibo Jiang
- Centre for Microscopy, Characterisation, and Analysis, The University of Western Australia
| | - Michael Ploug
- Finsen Laboratory, Rigshospitalet, 2200 Copenhagen N, Denmark; Biotech Research and Innovation Centre (BRIC), University of Copenhagen, 220 Copenhagen N, Denmark.
| |
Collapse
|
19
|
Morita SY. Metabolism and Modification of Apolipoprotein B-Containing Lipoproteins Involved in Dyslipidemia and Atherosclerosis. Biol Pharm Bull 2016; 39:1-24. [DOI: 10.1248/bpb.b15-00716] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Shin-ya Morita
- Department of Pharmacy, Shiga University of Medical Science Hospital
| |
Collapse
|
20
|
Batluk J, Leonards CO, Grittner U, Lange KS, Schreiber SJ, Endres M, Ebinger M. Triglycerides and carotid intima-media thickness in ischemic stroke patients. Atherosclerosis 2015; 243:186-91. [DOI: 10.1016/j.atherosclerosis.2015.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 08/26/2015] [Accepted: 09/03/2015] [Indexed: 11/25/2022]
|
21
|
Li H, Han Y, Qi R, Wang Y, Zhang X, Yu M, Tang Y, Wang M, Shu YN, Huang W, Liu X, Rodrigues B, Han M, Liu G. Aggravated restenosis and atherogenesis in ApoCIII transgenic mice but lack of protection in ApoCIII knockouts: the effect of authentic triglyceride-rich lipoproteins with and without ApoCIII. Cardiovasc Res 2015; 107:579-89. [PMID: 26160324 DOI: 10.1093/cvr/cvv192] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 06/30/2015] [Indexed: 11/13/2022] Open
Abstract
AIM Previously, our group and others have demonstrated a causative relationship between severe hypertriglyceridaemia and atherogenesis in mice. Furthermore, clinical investigations have shown high levels of plasma Apolipoprotein C-III (ApoCIII) associated with hypertriglyceridaemia and even cardiovascular disease. However, it remains unclear whether ApoCIII affects restenosis in vivo, and whether such an effect is mediated by ApoCIII alone, or in combination with hypertriglyceridaemia. We sought to investigate ApoCIII in restenosis and clarify how smooth muscle cells (SMCs) respond to authentic triglyceride-rich lipoproteins (TRLs) with or without ApoCIII (TRLs ± ApoCIII). METHODS AND RESULTS ApoCIII transgenic (ApoCIIItg) and knockout (ApoCIII-/-) mice underwent endothelial denudation to model restenosis. Here, ApoCIIItg mice displayed severe hypertriglyceridaemia and increased neointimal formation compared with wild-type (WT) or ApoCIII-/- mice. Furthermore, increased proliferating cell nuclear antigen (PCNA)-positive cells, Mac-3, and vascular cell adhesion protein-1 (VCAM-1) expression, and 4-hydroxynonenal (4HNE) production were found in lesion sites. ApoCIIItg and ApoCIII-/- mice were then crossed to low-density lipoprotein receptor-deficient (Ldlr-/-) mice and fed an atherogenic diet. ApoCIIItg/Ldlr-/- mice had significantly increased atherosclerotic lesions. However, there was no statistical difference in restenosis between ApoCIII-/- and WT mice, and in atherosclerosis between ApoCIII/Ldlr double knockout and Ldlr-/- mice. SMCs were then incubated in vitro with authentic TRLs ± ApoCIII isolated from extreme hypertriglyceridaemia glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1-deficient (GPIHBP1-/-) mice crossed with ApoCIIItg or ApoCIII-/- mice. It was shown that TRLs + ApoCIII promoted SMC proliferation, VCAM-1 expression, and reactive oxygen species (ROS) production, and activated the Akt pathway. Scavenging ROS significantly reduced SMC activation caused by TRLs + ApoCIII. CONCLUSIONS Severe hypertriglyceridaemia resulting from ApoCIII overexpression promotes restenosis and atherosclerosis. Furthermore, we demonstrated that TRLs + ApoCIII promotes SMC proliferation.
Collapse
Affiliation(s)
- Haibo Li
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing 100191, China
| | - Yingchun Han
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing 100191, China
| | - Rong Qi
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing 100191, China
| | - Yuhui Wang
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing 100191, China
| | - Xiaohong Zhang
- Department of Laboratory Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Maomao Yu
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing 100191, China
| | - Yin Tang
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing 100191, China
| | - Mengyu Wang
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing 100191, China
| | - Ya-Nan Shu
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, No. 361, Zhongshan East Rd, Shijiazhuang 050017, China
| | - Wei Huang
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing 100191, China
| | - Xinfeng Liu
- Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Brian Rodrigues
- Faculty of Pharmaceutical Sciences, The University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC, Canada V6T 1Z3
| | - Mei Han
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, No. 361, Zhongshan East Rd, Shijiazhuang 050017, China
| | - George Liu
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing 100191, China
| |
Collapse
|
22
|
Liu C, Gates KP, Fang L, Amar MJ, Schneider DA, Geng H, Huang W, Kim J, Pattison J, Zhang J, Witztum JL, Remaley AT, Dong PD, Miller YI. Apoc2 loss-of-function zebrafish mutant as a genetic model of hyperlipidemia. Dis Model Mech 2015; 8:989-98. [PMID: 26044956 PMCID: PMC4527288 DOI: 10.1242/dmm.019836] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 05/29/2015] [Indexed: 12/27/2022] Open
Abstract
Apolipoprotein C-II (APOC2) is an obligatory activator of lipoprotein lipase. Human patients with APOC2 deficiency display severe hypertriglyceridemia while consuming a normal diet, often manifesting xanthomas, lipemia retinalis and pancreatitis. Hypertriglyceridemia is also an important risk factor for development of cardiovascular disease. Animal models to study hypertriglyceridemia are limited, with no Apoc2-knockout mouse reported. To develop a genetic model of hypertriglyceridemia, we generated an apoc2 mutant zebrafish characterized by the loss of Apoc2 function. apoc2 mutants show decreased plasma lipase activity and display chylomicronemia and severe hypertriglyceridemia, which closely resemble the phenotype observed in human patients with APOC2 deficiency. The hypertriglyceridemia in apoc2 mutants is rescued by injection of plasma from wild-type zebrafish or by injection of a human APOC2 mimetic peptide. Consistent with a previous report of a transient apoc2 knockdown, apoc2 mutant larvae have a minor delay in yolk consumption and angiogenesis. Furthermore, apoc2 mutants fed a normal diet accumulate lipid and lipid-laden macrophages in the vasculature, which resemble early events in the development of human atherosclerotic lesions. In addition, apoc2 mutant embryos show ectopic overgrowth of pancreas. Taken together, our data suggest that the apoc2 mutant zebrafish is a robust and versatile animal model to study hypertriglyceridemia and the mechanisms involved in the pathogenesis of associated human diseases. Highlighted Article: Apoc2 loss-of-function zebrafish display severe hypertriglyceridemia, which is characteristic of human patients with defective lipoprotein lipase activity.
Collapse
Affiliation(s)
- Chao Liu
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Keith P Gates
- Sanford Children's Health Research Center, Programs in Genetic Disease and Development and Aging, and Stem Cell and Regenerative Biology, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - Longhou Fang
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Marcelo J Amar
- Lipoprotein Metabolism Section, Cardiopulmonary Branch, NHLBI, NIH, Bethesda, MD, USA
| | - Dina A Schneider
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Honglian Geng
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Wei Huang
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Jungsu Kim
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Jennifer Pattison
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Jian Zhang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Joseph L Witztum
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Alan T Remaley
- Lipoprotein Metabolism Section, Cardiopulmonary Branch, NHLBI, NIH, Bethesda, MD, USA
| | - P Duc Dong
- Sanford Children's Health Research Center, Programs in Genetic Disease and Development and Aging, and Stem Cell and Regenerative Biology, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - Yury I Miller
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| |
Collapse
|
23
|
Wakita K, Morita SY, Okamoto N, Takata E, Handa T, Nakano M. Chylomicron remnant model emulsions induce intracellular cholesterol accumulation and cell death due to lysosomal destabilization. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:598-604. [DOI: 10.1016/j.bbalip.2015.01.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 01/15/2015] [Accepted: 01/27/2015] [Indexed: 10/24/2022]
|
24
|
Abstract
Cardiovascular disease is the major cause of death in most developed nations and the social and economic burden of this disease is quite high. Atherosclerosis is a major underlying basis for most cardiovascular diseases including myocardial infarction and stroke. Genetically modified mouse models, particularly mice deficient in apoprotein E or the LDL receptor, have been widely used in preclinical atherosclerosis studies to gain insight into the mechanisms underlying this pathology. This chapter reviews several mouse models of atherosclerosis progression and regression as well as the role of immune cells in disease progression and the genetics of murine atherogenesis.
Collapse
Affiliation(s)
- Godfrey S Getz
- Department of Pathology, University of Chicago, Box MC 1089, 5841 S. Maryland Avenue, Chicago, IL, 60637, USA.
| | - Catherine A Reardon
- Department of Pathology, University of Chicago, Box MC 1089, 5841 S. Maryland Avenue, Chicago, IL, 60637, USA
| |
Collapse
|
25
|
Jiang H, Goulbourne CN, Tatar A, Turlo K, Wu D, Beigneux AP, Grovenor CRM, Fong LG, Young SG. High-resolution imaging of dietary lipids in cells and tissues by NanoSIMS analysis. J Lipid Res 2014; 55:2156-66. [PMID: 25143463 DOI: 10.1194/jlr.m053363] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nanoscale secondary ion MS (NanoSIMS) imaging makes it possible to visualize stable isotope-labeled lipids in cells and tissues at 50 nm lateral resolution. Here we report the use of NanoSIMS imaging to visualize lipids in mouse cells and tissues. After administering stable isotope-labeled fatty acids to mice by gavage, NanoSIMS imaging allowed us to visualize neutral lipids in cytosolic lipid droplets in intestinal enterocytes, chylomicrons at the basolateral surface of enterocytes, and lipid droplets in cardiomyocytes and adipocytes. After an injection of stable isotope-enriched triglyceride-rich lipoproteins (TRLs), NanoSIMS imaging documented delivery of lipids to cytosolic lipid droplets in parenchymal cells. Using a combination of backscattered electron (BSE) and NanoSIMS imaging, it was possible to correlate the chemical data provided by NanoSIMS with high-resolution BSE images of cell morphology. This combined imaging approach allowed us to visualize stable isotope-enriched TRLs along the luminal face of heart capillaries and the lipids within heart capillary endothelial cells. We also observed examples of TRLs within the subendothelial spaces of heart capillaries. NanoSIMS imaging provided evidence of defective transport of lipids from the plasma LPs to adipocytes and cardiomyocytes in mice deficient in glycosylphosphatidylinositol-anchored HDL binding protein 1.
Collapse
Affiliation(s)
- Haibo Jiang
- Materials Department, Oxford University, Oxford, United Kingdom
| | - Chris N Goulbourne
- Departments of Medicine University of California, Los Angeles, Los Angeles, CA
| | - Angelica Tatar
- Departments of Medicine University of California, Los Angeles, Los Angeles, CA
| | - Kirsten Turlo
- Departments of Medicine University of California, Los Angeles, Los Angeles, CA
| | - Daniel Wu
- Departments of Medicine University of California, Los Angeles, Los Angeles, CA
| | - Anne P Beigneux
- Departments of Medicine University of California, Los Angeles, Los Angeles, CA
| | | | - Loren G Fong
- Departments of Medicine University of California, Los Angeles, Los Angeles, CA
| | - Stephen G Young
- Departments of Medicine University of California, Los Angeles, Los Angeles, CA Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA
| |
Collapse
|
26
|
Abstract
The endothelium is often viewed solely as the barrier that prevents the penetration of circulating lipoproteins into the arterial wall. However, recent research has demonstrated that the endothelium has an important part in regulating circulating fatty acids and lipoproteins, and is in turn affected by these lipids/lipoproteins in ways that appear to have important repercussions for atherosclerosis. Thus, a number of potentially toxic lipids are produced during lipolysis of lipoproteins at the endothelial cell surface. Catabolism of triglyceride-rich lipoproteins creates free fatty acids that are readily taken up by endothelial cells, and, likely through the action of acyl-CoA synthetases, exacerbate inflammatory processes. In this article, we review how the endothelium participates in lipoprotein metabolism, how lipids alter endothelial functions, and how lipids are internalized, processed, and transported into the subendothelial space. Finally, we address the many endothelial changes that might promote atherogenesis, especially in the setting of diabetes.
Collapse
Affiliation(s)
- Ira J Goldberg
- Department of Medicine, Division of Preventive Medicine & Nutrition, Columbia University College of Physicians and Surgeons, 630 West 168th Street, New York, NY, 10032, USA,
| | | |
Collapse
|
27
|
Adeyo O, Allan BB, Barnes RH 2nd, Goulbourne CN, Tatar A, Tu Y, Young LC, Weinstein MM, Tontonoz P, Fong LG, Beigneux AP, Young SG. Palmoplantar keratoderma along with neuromuscular and metabolic phenotypes in Slurp1-deficient mice. J Invest Dermatol 2014; 134:1589-98. [PMID: 24499735 DOI: 10.1038/jid.2014.19] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 12/03/2013] [Accepted: 12/07/2013] [Indexed: 01/11/2023]
Abstract
Mutations in SLURP1 cause mal de Meleda, a rare palmoplantar keratoderma (PPK). SLURP1 is a secreted protein that is expressed highly in keratinocytes but has also been identified elsewhere (e.g., spinal cord neurons). Here, we examined Slurp1-deficient mice (Slurp1−/−) created by replacing exon 2 with β-gal and neo cassettes. Slurp1−/− mice developed severe PPK characterized by increased keratinocyte proliferation, an accumulation of lipid droplets in the stratum corneum, and a water barrier defect. In addition, Slurp1−/− mice exhibited reduced adiposity, protection from obesity on a high-fat diet, low plasma lipid levels, and a neuromuscular abnormality (hind limb clasping). Initially, it was unclear whether the metabolic and neuromuscular phenotypes were due to Slurp1 deficiency because we found that the targeted Slurp1 mutation reduced the expression of several neighboring genes (e.g., Slurp2, Lypd2). We therefore created a new line of knockout mice (Slurp1X−/− mice) with a simple nonsense mutation in exon 2. The Slurp1X mutation did not reduce the expression of adjacent genes, but Slurp1X−/− mice exhibited all of the phenotypes observed in the original line of knockout mice. Thus, Slurp1 deficiency in mice elicits metabolic and neuromuscular abnormalities in addition to PPK.
Collapse
|
28
|
Jenkins NT, Padilla J, Thorne PK, Martin JS, Rector RS, Davis JW, Laughlin MH. Transcriptome-wide RNA sequencing analysis of rat skeletal muscle feed arteries. I. Impact of obesity. J Appl Physiol (1985) 2014; 116:1017-32. [PMID: 24436298 DOI: 10.1152/japplphysiol.01233.2013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
We employed next-generation RNA sequencing (RNA-Seq) technology to determine the influence of obesity on global gene expression in skeletal muscle feed arteries. Transcriptional profiles of the gastrocnemius and soleus muscle feed arteries (GFA and SFA, respectively) and aortic endothelial cell-enriched samples from obese Otsuka Long-Evans Tokushima Fatty (OLETF) and lean Long-Evans Tokushima Otsuka (LETO) rats were examined. Obesity produced 282 upregulated and 133 downregulated genes in SFA and 163 upregulated and 77 downregulated genes in GFA [false discovery rate (FDR) < 10%] with an overlap of 93 genes between the arteries. In LETO rats, there were 89 upregulated and 114 downregulated genes in the GFA compared with the SFA. There were 244 upregulated and 275 downregulated genes in OLETF rats (FDR < 10%) in the GFA compared with the SFA, with an overlap of 76 differentially expressed genes common to both LETO and OLETF rats in both the GFA and SFA. A total of 396 transcripts were found to be differentially expressed between LETO and OLETF in aortic endothelial cell-enriched samples. Overall, we found 1) the existence of heterogeneity in the transcriptional profile of the SFA and GFA within healthy LETO rats, 2) that this between-vessel heterogeneity was markedly exacerbated in the hyperphagic, obese OLETF rat, and 3) a greater number of genes whose expression was altered by obesity in the SFA compared with the GFA. Also, results indicate that in OLETF rats the GFA takes on a relatively more proatherogenic phenotype compared with the SFA.
Collapse
Affiliation(s)
- Nathan T Jenkins
- Department of Kinesiology, University of Georgia, Athens, Georgia
| | | | | | | | | | | | | |
Collapse
|
29
|
Abstract
At least 468 individual genes have been manipulated by molecular methods to study their effects on the initiation, promotion, and progression of atherosclerosis. Most clinicians and many investigators, even in related disciplines, find many of these genes and the related pathways entirely foreign. Medical schools generally do not attempt to incorporate the relevant molecular biology into their curriculum. A number of key signaling pathways are highly relevant to atherogenesis and are presented to provide a context for the gene manipulations summarized herein. The pathways include the following: the insulin receptor (and other receptor tyrosine kinases); Ras and MAPK activation; TNF-α and related family members leading to activation of NF-κB; effects of reactive oxygen species (ROS) on signaling; endothelial adaptations to flow including G protein-coupled receptor (GPCR) and integrin-related signaling; activation of endothelial and other cells by modified lipoproteins; purinergic signaling; control of leukocyte adhesion to endothelium, migration, and further activation; foam cell formation; and macrophage and vascular smooth muscle cell signaling related to proliferation, efferocytosis, and apoptosis. This review is intended primarily as an introduction to these key signaling pathways. They have become the focus of modern atherosclerosis research and will undoubtedly provide a rich resource for future innovation toward intervention and prevention of the number one cause of death in the modern world.
Collapse
Affiliation(s)
- Paul N Hopkins
- Cardiovascular Genetics, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA.
| |
Collapse
|
30
|
Ng DS. Diabetic Dyslipidemia: From Evolving Pathophysiological Insight to Emerging Therapeutic Targets. Can J Diabetes 2013; 37:319-26. [DOI: 10.1016/j.jcjd.2013.07.062] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Revised: 07/22/2013] [Accepted: 07/22/2013] [Indexed: 12/12/2022]
|
31
|
Abstract
Significant knowledge regarding different molecules involved in the transport of dietary fat into the circulation has been garnered. Studies point to the possibility that accumulation of intestine-derived lipoproteins in the plasma could contribute to atherosclerosis. This article provides a brief overview of dietary lipid metabolism and studies in mice supporting the hypothesis that intestinal lipoproteins contribute to atherosclerosis. Deficiencies in lipoprotein lipase and Gpihbp1, and overexpression of heparanse in mice, are associated with increases in atherosclerosis, suggesting that defects in catabolism of larger lipoproteins in the plasma contribute to atherosclerosis. Furthermore, inositol-requiring enzyme 1β-deficient mice that produce more intestinal lipoproteins also develop more atherosclerosis. Thus, increases in plasma intestinal lipoproteins due to either overproduction or reduced catabolism result in augmented atherosclerosis. Intestinal lipoproteins tend to adhere strongly to subendothelial proteoglycans, elicit an inflammatory response by endothelial cells and activate macrophages, contributing to the initiation and progression of the disease. Thus, molecules that reduce intestinal lipid absorption can be useful in lowering atherosclerosis.
Collapse
Affiliation(s)
- M Mahmood Hussain
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY 11797, USA ; Department of Pediatrics, SUNY Downstate Medical Center, Brooklyn, NY 11797, USA
| | - Tung Ming Leung
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY 11797, USA ; Department of Pediatrics, SUNY Downstate Medical Center, Brooklyn, NY 11797, USA
| | - Liye Zhou
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY 11797, USA ; Department of Pediatrics, SUNY Downstate Medical Center, Brooklyn, NY 11797, USA
| | - Sarah Abu-Merhi
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY 11797, USA ; Department of Pediatrics, SUNY Downstate Medical Center, Brooklyn, NY 11797, USA
| |
Collapse
|
32
|
Guay SP, Gaudet D, Brisson D. The g.-469G>A polymorphism in the GPIHBP1 gene promoter is associated with hypertriglyceridemia and has an additive effect on the risk conferred by LPL defective alleles. Nutr Metab Cardiovasc Dis 2013; 23:358-365. [PMID: 21978733 DOI: 10.1016/j.numecd.2011.08.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 08/09/2011] [Accepted: 08/10/2011] [Indexed: 11/21/2022]
Abstract
BACKGROUND AND AIMS Hypertriglyceridemia (hyperTG) is a component of the metabolic syndrome and a cardiovascular or pancreatitis risk factor. Although both genetic and environmental factors influence its expression, the biological component of hyperTG is still underestimated and has been reported in 10-20% of cases only. Given its key role in the lipolysis of TG-rich lipoproteins, glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) is a biological candidate for hyperTG. The aim of this study was to assess the association of new GPIHBP1 gene variants with hyperTG (fasting plasma TG values ≥ 2.0 mmol/L). METHODS AND RESULTS Sequencing the GPIHBP1 gene identified a g.-469G > A (rs72691625) polymorphism in the promoter. A sample of 541 Caucasians (263 normoTG and 278 hyperTG) was then screened for this polymorphism using a 5'nuclease TaqMan. In multivariate analyses, GPIHBP1 g.-469G > A polymorphism carriers were at significantly higher risk of hyperTG (≥ 2.0 mmol/L) than non-carriers, the odds ratio (OR) being 1.67 (p = 0.025) among heterozygotes and 5.70 (p = 0.004) in homozygotes. The simultaneous presence of loss-of-function LPL polymorphisms had an incremental additive effect on the risk of hyperTG (OR: 7.30; p < 0.001), highlighting the importance of gene-gene interactions in the expression of hyperTG. CONCLUSIONS In this study, the g.-469G >A polymorphism in the GPIHBP1 gene promoter was associated with an increased risk of hyperTG and had an additive effect on the risk conferred by LPL defective alleles.
Collapse
Affiliation(s)
- S P Guay
- Department of Medicine, Université de Montréal, ECOGENE-21 and Lipid Clinic, Chicoutimi Hospital, Saguenay, QC, Canada.
| | | | | |
Collapse
|
33
|
Abstract
All organisms use fatty acids (FAs) for energy substrates and as precursors for membrane and signaling lipids. The most efficient way to transport and store FAs is in the form of triglycerides (TGs); however, TGs are not capable of traversing biological membranes and therefore need to be cleaved by TG hydrolases ("lipases") before moving in or out of cells. This biochemical process is generally called "lipolysis." Intravascular lipolysis degrades lipoprotein-associated TGs to FAs for their subsequent uptake by parenchymal cells, whereas intracellular lipolysis generates FAs and glycerol for their release (in the case of white adipose tissue) or use by cells (in the case of other tissues). Although the importance of lipolysis has been recognized for decades, many of the key proteins involved in lipolysis have been uncovered only recently. Important new developments include the discovery of glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1), the molecule that moves lipoprotein lipase from the interstitial spaces to the capillary lumen, and the discovery of adipose triglyceride lipase (ATGL) and comparative gene identification-58 (CGI-58) as crucial molecules in the hydrolysis of TGs within cells. This review summarizes current views of lipolysis and highlights the relevance of this process to human disease.
Collapse
Affiliation(s)
- Stephen G. Young
- Department of Medicine
- Department of Human Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California 90095
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| |
Collapse
|
34
|
Yamamoto H, Onishi M, Miyamoto N, Oki R, Ueda H, Ishigami M, Hiraoka H, Matsuzawa Y, Kihara S. Novel Combined GPIHBP1 Mutations in a Patient with Hypertriglyceridemia Associated with CAD. J Atheroscler Thromb 2013; 20:777-84. [DOI: 10.5551/jat.18861] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
35
|
Adeyo O, Goulbourne CN, Bensadoun A, Beigneux AP, Fong LG, Young SG. Glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 and the intravascular processing of triglyceride-rich lipoproteins. J Intern Med 2012; 272:528-40. [PMID: 23020258 PMCID: PMC3940157 DOI: 10.1111/joim.12003] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Lipoprotein lipase (LPL) is produced by parenchymal cells, mainly adipocytes and myocytes, but is involved in hydrolysing triglycerides in plasma lipoproteins at the capillary lumen. For decades, the mechanism by which LPL reaches its site of action in capillaries was unclear, but this mystery was recently solved. Glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1), a glycosylphosphatidylinositol-anchored protein of capillary endothelial cells, 'picks up' LPL from the interstitial spaces and shuttles it across endothelial cells to the capillary lumen. When GPIHBP1 is absent, LPL is mislocalized to the interstitial spaces, leading to severe hypertriglyceridaemia. Some cases of hypertriglyceridaemia in humans are caused by GPIHBP1 mutations that interfere with the ability of GPIHBP1 to bind to LPL, and some are caused by LPL mutations that impair the ability of LPL to bind to GPIHBP1. Here, we review recent progress in understanding the role of GPIHBP1 in health and disease and discuss some of the remaining unresolved issues regarding the processing of triglyceride-rich lipoproteins.
Collapse
Affiliation(s)
- O Adeyo
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | | | | | | | | | | |
Collapse
|
36
|
|
37
|
Berglund L, Brunzell JD, Goldberg AC, Goldberg IJ, Sacks F, Murad MH, Stalenhoef AFH. Evaluation and treatment of hypertriglyceridemia: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2012; 97:2969-89. [PMID: 22962670 PMCID: PMC3431581 DOI: 10.1210/jc.2011-3213] [Citation(s) in RCA: 517] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE The aim was to develop clinical practice guidelines on hypertriglyceridemia. PARTICIPANTS The Task Force included a chair selected by The Endocrine Society Clinical Guidelines Subcommittee (CGS), five additional experts in the field, and a methodologist. The authors received no corporate funding or remuneration. CONSENSUS PROCESS Consensus was guided by systematic reviews of evidence, e-mail discussion, conference calls, and one in-person meeting. The guidelines were reviewed and approved sequentially by The Endocrine Society's CGS and Clinical Affairs Core Committee, members responding to a web posting, and The Endocrine Society Council. At each stage, the Task Force incorporated changes in response to written comments. CONCLUSIONS The Task Force recommends that the diagnosis of hypertriglyceridemia be based on fasting levels, that mild and moderate hypertriglyceridemia (triglycerides of 150-999 mg/dl) be diagnosed to aid in the evaluation of cardiovascular risk, and that severe and very severe hypertriglyceridemia (triglycerides of > 1000 mg/dl) be considered a risk for pancreatitis. The Task Force also recommends that patients with hypertriglyceridemia be evaluated for secondary causes of hyperlipidemia and that subjects with primary hypertriglyceridemia be evaluated for family history of dyslipidemia and cardiovascular disease. The Task Force recommends that the treatment goal in patients with moderate hypertriglyceridemia be a non-high-density lipoprotein cholesterol level in agreement with National Cholesterol Education Program Adult Treatment Panel guidelines. The initial treatment should be lifestyle therapy; a combination of diet modification and drug therapy may also be considered. In patients with severe or very severe hypertriglyceridemia, a fibrate should be used as a first-line agent.
Collapse
Affiliation(s)
- Lars Berglund
- University of California, Davis, Sacramento, California 95817, USA
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Schwartz EA, Reaven PD. Lipolysis of triglyceride-rich lipoproteins, vascular inflammation, and atherosclerosis. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:858-66. [DOI: 10.1016/j.bbalip.2011.09.021] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Revised: 09/29/2011] [Accepted: 09/30/2011] [Indexed: 01/23/2023]
|
39
|
Klop B, Castro Cabezas M. Chylomicrons: A Key Biomarker and Risk Factor for Cardiovascular Disease and for the Understanding of Obesity. Curr Cardiovasc Risk Rep 2011. [DOI: 10.1007/s12170-011-0215-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
40
|
Ortega A, Varela LM, Bermudez B, Lopez S, Abia R, Muriana FJG. Dietary fatty acids linking postprandial metabolic response and chronic diseases. Food Funct 2011; 3:22-7. [PMID: 22020286 DOI: 10.1039/c1fo10085h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chronic diseases are by far one of the main causes of mortality in the world. One of the current global recommendations to counteract disability and premature death resulting from chronic diseases is to decrease the consumption of energy-dense high-fat diets, particularly those rich in saturated fatty acids (SFA). The most effective replacement for SFA in terms of risk factor outcomes for chronic disease are polyunsaturated fatty acids (PUFA) and monounsaturated fatty acids (MUFA). The biochemical basis for healthy benefits of such a dietary pattern has been widely evaluated under fasting conditions. However, the increasing amount of data available from multiple studies suggest that the postprandial state, i.e., "the period that comprises and follows a meal", plays an important, yet underappreciated, role in the genesis of numerous pathological conditions. In this review, the potential of MUFA, PUFA, and SFA to postprandially affect selected metabolic abnormalities related to chronic diseases is discussed.
Collapse
Affiliation(s)
- Almudena Ortega
- Laboratory of Cellular and Molecular Nutrition, Instituto de la Grasa (CSIC), 41012 Seville, Spain
| | | | | | | | | | | |
Collapse
|
41
|
Ding Y, Zhang L, Wang Y, Huang W, Tang Y, Bai L, Ross CJ, Hayden MR, Liu G. Amelioration of hypertriglyceridemia with hypo-alpha-cholesterolemia in LPL deficient mice by hematopoietic cell-derived LPL. PLoS One 2011; 6:e25620. [PMID: 21980507 DOI: 10.1371/journal.pone.0025620] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 09/08/2011] [Indexed: 11/20/2022] Open
Abstract
Background Macrophage-derived lipoprotein lipase (LPL) has been shown uniformly to promote atherosclerotic lesion formation while the extent to which it affects plasma lipid and lipoprotein levels varies in wild-type and hypercholesterolemic mice. It is known that high levels of LPL in the bulk of adipose tissue and skeletal muscle would certainly mask the contribution of macrophage LPL to metabolism of plasma lipoprotein. Therefore, we chose LPL deficient (LPL-/-) mice with severe hypertriglyceridemia as an alternative model to assess the role of macrophage LPL in plasma lipoprotein metabolism via bone marrow transplant, through which LPL will be produced mainly by hematopoietic cell-derived macrophages. Methods and Results Hypertriglyceridemic LPL-/- mice were lethally irradiated, then transplanted with bone marrow from wild-type (LPL+/+) or LPL-/- mice, respectively. Sixteen weeks later, LPL+/+ →LPL-/- mice displayed significant reduction in plasma levels of triglyceride and cholesterol (408±44.9 vs. 2.7±0.5×103 and 82.9±7.1 vs. 229.1±30.6 mg/dl, p<0.05, respectively), while a 2.7-fold increase in plasma high density lipoprotein- cholesterol (p<0.01) was observed, compared with LPL-/-→LPL-/- control mice. The clearance rate for the oral fat load test in LPL+/+ →LPL-/- mice was faster than that in LPL-/-→LPL-/- mice, but slower than that in wild-type mice. Liver triglyceride content in LPL+/+→LPL-/- mice was also significantly increased, compared with LPL-/-→LPL-/- mice (6.8±0.7 vs. 4.6±0.5 mg/g wet tissue, p<0.05, n = 6). However, no significant change was observed in the expression levels of genes involved in hepatic lipid metabolism between the two groups. Conclusions Hematopoietic cell-derived LPL could efficiently ameliorate severe hypertriglyceridemia and hypo-alpha-cholesterolemia at the compensation of increased triglyceride content of liver in LPL-/- mice.
Collapse
|
42
|
Young SG, Davies BSJ, Voss CV, Gin P, Weinstein MM, Tontonoz P, Reue K, Bensadoun A, Fong LG, Beigneux AP. GPIHBP1, an endothelial cell transporter for lipoprotein lipase. J Lipid Res 2011; 52:1869-84. [PMID: 21844202 DOI: 10.1194/jlr.r018689] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Interest in lipolysis and the metabolism of triglyceride-rich lipoproteins was recently reignited by the discovery of severe hypertriglyceridemia (chylomicronemia) in glycosylphosphatidylinositol-anchored high density lipoprotein-binding protein 1 (GPIHBP1)-deficient mice. GPIHBP1 is expressed exclusively in capillary endothelial cells and binds lipoprotein lipase (LPL) avidly. These findings prompted speculation that GPIHBP1 serves as a binding site for LPL in the capillary lumen, creating "a platform for lipolysis." More recent studies have identified a second and more intriguing role for GPIHBP1-picking up LPL in the subendothelial spaces and transporting it across endothelial cells to the capillary lumen. Here, we review the studies that revealed that GPIHBP1 is the LPL transporter and discuss which amino acid sequences are required for GPIHBP1-LPL interactions. We also discuss the human genetics of LPL transport, focusing on cases of chylomicronemia caused by GPIHBP1 mutations that abolish GPIHBP1's ability to bind LPL, and LPL mutations that prevent LPL binding to GPIHBP1.
Collapse
Affiliation(s)
- Stephen G Young
- Department of Medicine, University of California, Los Angeles, CA 90095, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Chapman MJ, Ginsberg HN, Amarenco P, Andreotti F, Borén J, Catapano AL, Descamps OS, Fisher E, Kovanen PT, Kuivenhoven JA, Lesnik P, Masana L, Nordestgaard BG, Ray KK, Reiner Z, Taskinen MR, Tokgözoglu L, Tybjærg-Hansen A, Watts GF. Triglyceride-rich lipoproteins and high-density lipoprotein cholesterol in patients at high risk of cardiovascular disease: evidence and guidance for management. Eur Heart J 2011. [PMID: 21531743 DOI: 10.1093/eurheartj/ehj112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Even at low-density lipoprotein cholesterol (LDL-C) goal, patients with cardiometabolic abnormalities remain at high risk of cardiovascular events. This paper aims (i) to critically appraise evidence for elevated levels of triglyceride-rich lipoproteins (TRLs) and low levels of high-density lipoprotein cholesterol (HDL-C) as cardiovascular risk factors, and (ii) to advise on therapeutic strategies for management. Current evidence supports a causal association between elevated TRL and their remnants, low HDL-C, and cardiovascular risk. This interpretation is based on mechanistic and genetic studies for TRL and remnants, together with the epidemiological data suggestive of the association for circulating triglycerides and cardiovascular disease. For HDL, epidemiological, mechanistic, and clinical intervention data are consistent with the view that low HDL-C contributes to elevated cardiovascular risk; genetic evidence is unclear however, potentially reflecting the complexity of HDL metabolism. The Panel believes that therapeutic targeting of elevated triglycerides (≥ 1.7 mmol/L or 150 mg/dL), a marker of TRL and their remnants, and/or low HDL-C (<1.0 mmol/L or 40 mg/dL) may provide further benefit. The first step should be lifestyle interventions together with consideration of compliance with pharmacotherapy and secondary causes of dyslipidaemia. If inadequately corrected, adding niacin or a fibrate, or intensifying LDL-C lowering therapy may be considered. Treatment decisions regarding statin combination therapy should take into account relevant safety concerns, i.e. the risk of elevation of blood glucose, uric acid or liver enzymes with niacin, and myopathy, increased serum creatinine and cholelithiasis with fibrates. These recommendations will facilitate reduction in the substantial cardiovascular risk that persists in patients with cardiometabolic abnormalities at LDL-C goal.
Collapse
Affiliation(s)
- M John Chapman
- European Atherosclerosis Society, INSERM UMR-S939, Pitié-Salpetriere University Hospital, Paris 75651, France.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Chapman MJ, Ginsberg HN, Amarenco P, Andreotti F, Borén J, Catapano AL, Descamps OS, Fisher E, Kovanen PT, Kuivenhoven JA, Lesnik P, Masana L, Nordestgaard BG, Ray KK, Reiner Z, Taskinen MR, Tokgözoglu L, Tybjærg-Hansen A, Watts GF. Triglyceride-rich lipoproteins and high-density lipoprotein cholesterol in patients at high risk of cardiovascular disease: evidence and guidance for management. Eur Heart J 2011; 32:1345-61. [PMID: 21531743 PMCID: PMC3105250 DOI: 10.1093/eurheartj/ehr112] [Citation(s) in RCA: 859] [Impact Index Per Article: 66.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Even at low-density lipoprotein cholesterol (LDL-C) goal, patients with cardiometabolic abnormalities remain at high risk of cardiovascular events. This paper aims (i) to critically appraise evidence for elevated levels of triglyceride-rich lipoproteins (TRLs) and low levels of high-density lipoprotein cholesterol (HDL-C) as cardiovascular risk factors, and (ii) to advise on therapeutic strategies for management. Current evidence supports a causal association between elevated TRL and their remnants, low HDL-C, and cardiovascular risk. This interpretation is based on mechanistic and genetic studies for TRL and remnants, together with the epidemiological data suggestive of the association for circulating triglycerides and cardiovascular disease. For HDL, epidemiological, mechanistic, and clinical intervention data are consistent with the view that low HDL-C contributes to elevated cardiovascular risk; genetic evidence is unclear however, potentially reflecting the complexity of HDL metabolism. The Panel believes that therapeutic targeting of elevated triglycerides (≥1.7 mmol/L or 150 mg/dL), a marker of TRL and their remnants, and/or low HDL-C (<1.0 mmol/L or 40 mg/dL) may provide further benefit. The first step should be lifestyle interventions together with consideration of compliance with pharmacotherapy and secondary causes of dyslipidaemia. If inadequately corrected, adding niacin or a fibrate, or intensifying LDL-C lowering therapy may be considered. Treatment decisions regarding statin combination therapy should take into account relevant safety concerns, i.e. the risk of elevation of blood glucose, uric acid or liver enzymes with niacin, and myopathy, increased serum creatinine and cholelithiasis with fibrates. These recommendations will facilitate reduction in the substantial cardiovascular risk that persists in patients with cardiometabolic abnormalities at LDL-C goal.
Collapse
Affiliation(s)
- M John Chapman
- European Atherosclerosis Society, INSERM UMR-S939, Pitié-Salpetriere University Hospital, Paris 75651, France.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Abstract
The purpose of this article is to review the basic and clinical science relating plasma triglycerides and cardiovascular disease. Although many aspects of the basic physiology of triglyceride production, its plasma transport, and its tissue uptake have been known for several decades, the relationship of plasma triglyceride levels to vascular disease is uncertain. Are triglyceride-rich lipoproteins, their influence on high-density lipoprotein and low-density lipoprotein, or the underlying diseases that lead to defects in triglyceride metabolism the culprit? Animal models have failed to confirm that anything other than early fatty lesions can be produced by triglyceride-rich lipoproteins. Metabolic products of triglyceride metabolism can be toxic to arterial cells; however, these studies are primarily in vitro. Correlative studies of fasting and postprandial triglycerides and genetic diseases implicate very-low-density lipoprotein and their remnants and chylomicron remnants in atherosclerosis development, but the concomitant alterations in other lipoproteins and other risk factors obscure any conclusions about direct relationships between disease and triglycerides. Genes that regulate triglyceride levels also correlate with vascular disease. Human intervention trials, however, have lacked an appropriately defined population and have produced outcomes without definitive conclusions. The time is more than ripe for new and creative approaches to understanding the relationship of triglycerides and heart disease.
Collapse
Affiliation(s)
- Ira J Goldberg
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
| | | | | |
Collapse
|
46
|
Drager LF, Li J, Shin MK, Reinke C, Aggarwal NR, Jun JC, Bevans-Fonti S, Sztalryd C, O'Byrne SM, Kroupa O, Olivecrona G, Blaner WS, Polotsky VY. Intermittent hypoxia inhibits clearance of triglyceride-rich lipoproteins and inactivates adipose lipoprotein lipase in a mouse model of sleep apnoea. Eur Heart J 2011; 33:783-90. [PMID: 21478490 DOI: 10.1093/eurheartj/ehr097] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
AIMS Delayed lipoprotein clearance is associated with atherosclerosis. This study examined whether chronic intermittent hypoxia (CIH), a hallmark of obstructive sleep apnoea (OSA), can lead to hyperlipidaemia by inhibiting clearance of triglyceride rich lipoproteins (TRLP). METHODS AND RESULTS Male C57BL/6J mice on high-cholesterol diet were exposed to 4 weeks of CIH or chronic intermittent air (control). FIO(2) was decreased to 6.5% once per minute during the 12 h light phase in the CIH group. After the exposure, we measured fasting lipid profile. TRLP clearance was assessed by oral gavage of retinyl palmitate followed by serum retinyl esters (REs) measurements at 0, 1, 2, 4, 10, and 24 h. Activity of lipoprotein lipase (LpL), a key enzyme of lipoprotein clearance, and levels of angiopoietin-like protein 4 (Angptl4), a potent inhibitor of the LpL activity, were determined in the epididymal fat pads, skeletal muscles, and heart. Chronic intermittent hypoxia induced significant increases in levels of total cholesterol and triglycerides, which occurred in TRLP and LDL fractions (P< 0.05 for each comparison). Compared with control mice, animals exposed to CIH showed increases in REs throughout first 10 h after oral gavage of retinyl palmitate (P< 0.05), indicating that CIH inhibited TRLP clearance. CIH induced a >5-fold decrease in LpL activity (P< 0.01) and an 80% increase in Angptl4 mRNA and protein levels in the epididymal fat, but not in the skeletal muscle or heart. CONCLUSIONS CIH decreases TRLP clearance and inhibits LpL activity in adipose tissue, which may contribute to atherogenesis observed in OSA.
Collapse
Affiliation(s)
- Luciano F Drager
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Johns Hopkins Asthma and Allergy Center, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Planer D, Metzger S, Zcharia E, Wexler ID, Vlodavsky I, Chajek-Shaul T. Role of heparanase on hepatic uptake of intestinal derived lipoprotein and fatty streak formation in mice. PLoS One 2011; 6:e18370. [PMID: 21483695 PMCID: PMC3070732 DOI: 10.1371/journal.pone.0018370] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Accepted: 03/06/2011] [Indexed: 12/20/2022] Open
Abstract
Background Heparanase modulates the level of heparan sulfate proteoglycans (HSPGs) which have an important role in multiple cellular processes. Recent studies indicate that HSPGs have an important function in hepatic lipoprotein handling and processes involving removal of lipoprotein particles. Principal Findings To determine the effects of decreased HSPGs chain length on lipoprotein metabolism and atherosclerosis, transgenic mice over-expressing the human heparanase gene were studied. Hepatic lipid uptake in hpa-Tg mice were evaluated by giving transgenic mice oral fat loads and labeled retinol. Sections of aorta from mice over-expressing heparanase (hpa-Tg) and controls (C57/BL6) fed an atherogenic diet were examined for evidence of atherosclerosis. Heparanase over-expression results in reduced hepatic clearance of postprandial lipoproteins and higher levels of fasting and postprandial serum triglycerides. Heparanase over-expression also induces formation of fatty streaks in the aorta. The mean lesion cross-sectional area in heparanase over-expressing mice was almost 6 times higher when compared to control mice (23,984 µm2±5,922 vs. 4,189 µm2±1,130, p<0.001). Conclusions Over-expression of heparanase demonstrates the importance of HSPGs for the uptake of intestinal derived lipoproteins and its role in the formation of fatty streaks.
Collapse
Affiliation(s)
- David Planer
- Department of Medicine, Hadassah-Hebrew University Medical Center, Mount Scopus, Jerusalem, Israel
| | - Shulamit Metzger
- Department of Medicine, Hadassah-Hebrew University Medical Center, Mount Scopus, Jerusalem, Israel
| | - Eyal Zcharia
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel
| | - Isaiah D. Wexler
- Department of Pediatrics, Hadassah-Hebrew University Medical Center, Mount Scopus, Jerusalem, Israel
| | - Israel Vlodavsky
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel
| | - Tova Chajek-Shaul
- Department of Medicine, Hadassah-Hebrew University Medical Center, Mount Scopus, Jerusalem, Israel
- * E-mail:
| |
Collapse
|
48
|
Gin P, Beigneux AP, Voss C, Davies BSJ, Beckstead JA, Ryan RO, Bensadoun A, Fong LG, Young SG. Binding preferences for GPIHBP1, a glycosylphosphatidylinositol-anchored protein of capillary endothelial cells. Arterioscler Thromb Vasc Biol 2010; 31:176-82. [PMID: 20966398 DOI: 10.1161/atvbaha.110.214718] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To define the ability of GPIHBP1 to bind other lipase family members and other apolipoproteins (apos) and lipoproteins. METHODS AND RESULTS GPIHBP1, a GPI-anchored lymphocyte antigen (Ly)6 protein of capillary endothelial cells, binds lipoprotein lipase (LPL) avidly, but its ability to bind related lipase family members has never been evaluated. As judged by cell-based and cell-free binding assays, LPL binds to GPIHBP1, but other members of the lipase family do not. We also examined the binding of apoAV-phospholipid disks to GPIHBP1. ApoAV binds avidly to GPIHBP1-transfected cells; this binding requires GPIHBP1's amino-terminal acidic domain and is independent of its cysteine-rich Ly6 domain (the latter domain is essential for LPL binding). GPIHBP1-transfected cells did not bind high-density lipoprotein. Chylomicrons bind avidly to GPIHBP1-transfected Chinese hamster ovary cells, but this binding is dependent on GPIHBP1's ability to bind LPL within the cell culture medium. CONCLUSIONS GPIHBP1 binds LPL but does not bind other lipase family members. GPIHBP1 binds apoAV but does not bind apoAI or high-density lipoprotein. The ability of GPIHBP1-transfected Chinese hamster ovary cells to bind chylomicrons is mediated by LPL; chylomicron binding does not occur unless GPIHBP1 first captures LPL from the cell culture medium.
Collapse
Affiliation(s)
- Peter Gin
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Abstract
PURPOSE OF REVIEW There are strong epidemiologic connections between plasma triglycerides and atherosclerosis. We will consider to what extent this goes back to derangements of the lipoprotein lipase (LPL) system. The roles of hepatic lipase and endothelial lipase will also be touched upon. RECENT FINDINGS Understanding of LPL action has taken major steps with the discovery of lipase maturation factor 1 as a specific endoplasmic reticulum chaperon needed for proper folding of the lipases, glycosylphosphatidylinositol-anchored HDL-binding protein 1 as an endothelial cell protein needed for transport and binding of LPL and some angiopoietin-like proteins that can modulate LPL activity. Studies of genetic variants continue to support the important roles of the lipases in lipoprotein metabolism and in atherosclerosis. CONCLUSION There are several ways by which derangement of the lipases may contribute to atherogenesis. Lipase actions are major determinants of plasma lipoprotein patterns. LPL activity must be modulated in relation to the physiological situation (feeding, fasting, exercise, etc.). Fatty acids and monoglycerides generated must be efficiently removed so that they do not endanger the integrity of the endothelium, cause lipotoxic reactions or both. In addition, the lipases may cause binding and endocytosis of lipoprotein particles in the artery wall.
Collapse
Affiliation(s)
- Gunilla Olivecrona
- Department of Medical Biosciences, Section on Physiological Chemistry, Umeå University, Umeå, Sweden.
| | | |
Collapse
|
50
|
Olafsen T, Young SG, Davies BSJ, Beigneux AP, Kenanova VE, Voss C, Young G, Wong KP, Barnes RH, Tu Y, Weinstein MM, Nobumori C, Huang SC, Goldberg IJ, Bensadoun A, Wu AM, Fong LG. Unexpected expression pattern for glycosylphosphatidylinositol-anchored HDL-binding protein 1 (GPIHBP1) in mouse tissues revealed by positron emission tomography scanning. J Biol Chem 2010; 285:39239-48. [PMID: 20889497 DOI: 10.1074/jbc.m110.171041] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glycosylphosphatidylinositol-anchored high density lipoprotein-binding protein 1 (GPIHBP1), a GPI-anchored endothelial cell protein, binds lipoprotein lipase (LPL) and transports it into the lumen of capillaries where it hydrolyzes triglycerides in lipoproteins. GPIHBP1 is assumed to be expressed mainly within the heart, skeletal muscle, and adipose tissue, the sites where most lipolysis occurs, but the tissue pattern of GPIHBP1 expression has never been evaluated systematically. Because GPIHBP1 is found on the luminal face of capillaries, we predicted that it would be possible to define GPIHBP1 expression patterns with radiolabeled GPIHBP1-specific antibodies and positron emission tomography (PET) scanning. In Gpihbp1(-/-) mice, GPIHBP1-specific antibodies were cleared slowly from the blood, and PET imaging showed retention of the antibodies in the blood pools (heart and great vessels). In Gpihbp1(+/+) mice, the antibodies were cleared extremely rapidly from the blood and, to our surprise, were taken up mainly by lung and liver. Immunofluorescence microscopy confirmed the presence of GPIHBP1 in the capillary endothelium of both lung and liver. In most tissues with high levels of Gpihbp1 expression, Lpl expression was also high, but the lung was an exception (very high Gpihbp1 expression and extremely low Lpl expression). Despite low Lpl transcript levels, however, LPL protein was readily detectable in the lung, suggesting that some of that LPL originates elsewhere and then is captured by GPIHBP1 in the lung. In support of this concept, lung LPL levels were significantly lower in Gpihbp1(-/-) mice than in Gpihbp1(+/+) mice. In addition, Lpl(-/-) mice expressing human LPL exclusively in muscle contained high levels of human LPL in the lung.
Collapse
Affiliation(s)
- Tove Olafsen
- Department of Molecular and Medical Pharmacology, California NanoSystems Institute, Los Angeles, California 90095, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|