1
|
Siddiqui H, Yevstigneyev N, Madani G, McCormick S. Approaches to Visualising Endocytosis of LDL-Related Lipoproteins. Biomolecules 2022; 12:biom12020158. [PMID: 35204658 PMCID: PMC8961563 DOI: 10.3390/biom12020158] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/20/2021] [Accepted: 01/12/2022] [Indexed: 02/04/2023] Open
Abstract
Endocytosis is the process by which molecules are actively transported into cells. It can take on a variety of forms depending on the cellular machinery involved ranging from specific receptor-mediated endocytosis to the less selective and actin-driven macropinocytosis. The plasma lipoproteins, which deliver lipids and other cargo to cells, have been intensely studied with respect to their endocytic uptake. One of the first molecules to be visualised undergoing endocytosis via a receptor-mediated, clathrin-dependent pathway was low-density lipoprotein (LDL). The LDL molecule has subsequently been shown to be internalised through multiple endocytic pathways. Dissecting the pathways of lipoprotein endocytosis has been crucial to understanding the regulation of plasma lipid levels and how lipids enter cells in the arterial wall to promote atherosclerosis. It has also aided understanding of the dysregulation that occurs in plasma lipid levels when molecules involved in uptake are defective, as is the case in familial hypercholesterolemia (FH). The aim of this review is to outline the many endocytic pathways utilised for lipoprotein uptake. It explores the various experimental approaches that have been applied to visualise lipoprotein endocytosis with an emphasis on LDL and its more complex counterpart, lipoprotein(a) [Lp(a)]. Finally, we look at new developments in lipoprotein visualisation that hold promise for scrutinising endocytic pathways to finer detail in the future.
Collapse
Affiliation(s)
- Halima Siddiqui
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand; (H.S.); (N.Y.); (G.M.)
- HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
| | - Nikita Yevstigneyev
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand; (H.S.); (N.Y.); (G.M.)
- HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
| | - Golnoush Madani
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand; (H.S.); (N.Y.); (G.M.)
- HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
| | - Sally McCormick
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand; (H.S.); (N.Y.); (G.M.)
- HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
- Correspondence:
| |
Collapse
|
2
|
Li H, Yu XH, Ou X, Ouyang XP, Tang CK. Hepatic cholesterol transport and its role in non-alcoholic fatty liver disease and atherosclerosis. Prog Lipid Res 2021; 83:101109. [PMID: 34097928 DOI: 10.1016/j.plipres.2021.101109] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 12/12/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a quickly emerging global health problem representing the most common chronic liver disease in the world. Atherosclerotic cardiovascular disease represents the leading cause of mortality in NAFLD patients. Cholesterol metabolism has a crucial role in the pathogenesis of both NAFLD and atherosclerosis. The liver is the major organ for cholesterol metabolism. Abnormal hepatic cholesterol metabolism not only leads to NAFLD but also drives the development of atherosclerotic dyslipidemia. The cholesterol level in hepatocytes reflects the dynamic balance between endogenous synthesis, uptake, esterification, and export, a process in which cholesterol is converted to neutral cholesteryl esters either for storage in cytosolic lipid droplets or for secretion as a major constituent of plasma lipoproteins, including very-low-density lipoproteins, chylomicrons, high-density lipoproteins, and low-density lipoproteins. In this review, we describe decades of research aimed at identifying key molecules and cellular players involved in each main aspect of hepatic cholesterol metabolism. Furthermore, we summarize the recent advances regarding the biological processes of hepatic cholesterol transport and its role in NAFLD and atherosclerosis.
Collapse
Affiliation(s)
- Heng Li
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan International Scientific and Technological Cooperation Base of Arteriosclerotic Disease, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China
| | - Xiao-Hua Yu
- Institute of Clinical Medicine, The Second Affiliated Hospital of Hainan Medical University, Haikou, Hainan 460106, China
| | - Xiang Ou
- Department of Endocrinology, the First Hospital of Changsha, Changsha, Hunan 410005, China
| | - Xin-Ping Ouyang
- Department of Physiology, Institute of Neuroscience Research, Hengyang Key Laboratory of Neurodegeneration and Cognitive Impairment, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China.
| | - Chao-Ke Tang
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan International Scientific and Technological Cooperation Base of Arteriosclerotic Disease, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China.
| |
Collapse
|
3
|
Santander-Ortega M, Plaza-Oliver M, Rodríguez-Robledo V, Castro-Vázquez L, Villaseca-González N, González-Fuentes J, Marcos P, Arroyo-Jiménez M, Lozano M. Colloids for drug delivery to the brain. J Drug Deliv Sci Technol 2017. [DOI: 10.1016/j.jddst.2017.07.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
4
|
Rahimi M, Safa KD, Salehi R. Co-delivery of doxorubicin and methotrexate by dendritic chitosan-g-mPEG as a magnetic nanocarrier for multi-drug delivery in combination chemotherapy. Polym Chem 2017. [DOI: 10.1039/c7py01701d] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Nanoparticulate drug delivery systems have the potential to improve the therapeutic efficacy of anticancer agents, and combination therapy is a promising strategy for clinical cancer treatment with synergistic effects.
Collapse
Affiliation(s)
- Mahdi Rahimi
- Department of Organic and Biochemistry
- Faculty of Chemistry
- University of Tabriz
- Tabriz 5166614766
- Iran
| | - Kazem D. Safa
- Department of Organic and Biochemistry
- Faculty of Chemistry
- University of Tabriz
- Tabriz 5166614766
- Iran
| | - Roya Salehi
- Drug Applied Research Centre and School of Advanced Medical Science
- Tabriz University of Medical Sciences
- Tabriz
- Iran
| |
Collapse
|
5
|
Srimanee A, Regberg J, Hällbrink M, Vajragupta O, Langel Ü. Role of scavenger receptors in peptide-based delivery of plasmid DNA across a blood-brain barrier model. Int J Pharm 2016; 500:128-35. [PMID: 26773601 DOI: 10.1016/j.ijpharm.2016.01.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 12/31/2015] [Accepted: 01/05/2016] [Indexed: 01/01/2023]
Abstract
Receptor-mediated transcytosis remains a major route for drug delivery across the blood-brain barrier (BBB). PepFect 32 (PF32), a peptide-based vector modified with targeting ligand (Angiopep-2) binding to low-density lipoprotein receptor-related protein-1 (LRP-1), was previously found to be a promising vector for plasmid delivery across an in vitro model of the BBB. Cellular uptake of PF32/plasmid DNA (pDNA) complexes was speculated the internalization via LRP-1 receptor. In this study, we prove that PF32/pDNA nanocomplexes are not only transported into brain endothelial cells via LRP-1 receptor-mediated endocytosis, but also via scavenger receptor class A and B (SCARA3, SCARA5, and SR-BI)-mediated endocytosis. SCARA3, SCARA5, and SR-BI are found to be expressed in the brain endothelial cells. Inhibition of these receptors leads to a reduction of the transfection. In conclusion, this study shows that scavenger receptors also play an essential role in the cellular uptake of the PF32/pDNA nanocomplexes.
Collapse
Affiliation(s)
- Artita Srimanee
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Mahidol University, 447 Sri-Ayudhya Rd., 10400 Bangkok, Thailand; Department of Neurochemistry, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden.
| | - Jakob Regberg
- Department of Neurochemistry, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Mattias Hällbrink
- Department of Neurochemistry, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Opa Vajragupta
- Excellent Center for Innovation in Drug Design and Discovery, Faculty of Pharmacy, Mahidol University, 447 Sri-Ayudhya Rd., 10400 Bangkok, Thailand
| | - Ülo Langel
- Department of Neurochemistry, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden; Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu, Estonia
| |
Collapse
|
6
|
Zannis VI, Fotakis P, Koukos G, Kardassis D, Ehnholm C, Jauhiainen M, Chroni A. HDL biogenesis, remodeling, and catabolism. Handb Exp Pharmacol 2015; 224:53-111. [PMID: 25522986 DOI: 10.1007/978-3-319-09665-0_2] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this chapter, we review how HDL is generated, remodeled, and catabolized in plasma. We describe key features of the proteins that participate in these processes, emphasizing how mutations in apolipoprotein A-I (apoA-I) and the other proteins affect HDL metabolism. The biogenesis of HDL initially requires functional interaction of apoA-I with the ATP-binding cassette transporter A1 (ABCA1) and subsequently interactions of the lipidated apoA-I forms with lecithin/cholesterol acyltransferase (LCAT). Mutations in these proteins either prevent or impair the formation and possibly the functionality of HDL. Remodeling and catabolism of HDL is the result of interactions of HDL with cell receptors and other membrane and plasma proteins including hepatic lipase (HL), endothelial lipase (EL), phospholipid transfer protein (PLTP), cholesteryl ester transfer protein (CETP), apolipoprotein M (apoM), scavenger receptor class B type I (SR-BI), ATP-binding cassette transporter G1 (ABCG1), the F1 subunit of ATPase (Ecto F1-ATPase), and the cubulin/megalin receptor. Similarly to apoA-I, apolipoprotein E and apolipoprotein A-IV were shown to form discrete HDL particles containing these apolipoproteins which may have important but still unexplored functions. Furthermore, several plasma proteins were found associated with HDL and may modulate its biological functions. The effect of these proteins on the functionality of HDL is the topic of ongoing research.
Collapse
Affiliation(s)
- Vassilis I Zannis
- Molecular Genetics, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, 02118, USA,
| | | | | | | | | | | | | |
Collapse
|
7
|
Fruhwürth S, Pavelka M, Bittman R, Kovacs WJ, Walter KM, Röhrl C, Stangl H. High-density lipoprotein endocytosis in endothelial cells. World J Biol Chem 2013; 4:131-140. [PMID: 24340136 PMCID: PMC3856308 DOI: 10.4331/wjbc.v4.i4.131] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 11/11/2013] [Accepted: 11/19/2013] [Indexed: 02/05/2023] Open
Abstract
AIM: To describe the way stations of high-density lipoprotein (HDL) uptake and its lipid exchange in endothelial cells in vitro and in vivo.
METHODS: A combination of fluorescence microscopy using novel fluorescent cholesterol surrogates and electron microscopy was used to analyze HDL endocytosis in great detail in primary human endothelial cells. Further, HDL uptake was quantified using radio-labeled HDL particles. To validate the in vitro findings mice were injected with fluorescently labeled HDL and particle uptake in the liver was analyzed using fluorescence microscopy.
RESULTS: HDL uptake occurred via clathrin-coated pits, tubular endosomes and multivesicular bodies in human umbilical vein endothelial cells. During uptake and resecretion, HDL-derived cholesterol was exchanged at a faster rate than cholesteryl oleate, resembling the HDL particle pathway seen in hepatic cells. In addition, lysosomes were not involved in this process and thus HDL degradation was not detectable. In vivo, we found HDL mainly localized in mouse hepatic endothelial cells. HDL was not detected in parenchymal liver cells, indicating that lipid transfer from HDL to hepatocytes occurs primarily via scavenger receptor, class B, type I mediated selective uptake without concomitant HDL endocytosis.
CONCLUSION: HDL endocytosis occurs via clathrin-coated pits, tubular endosomes and multivesicular bodies in human endothelial cells. Mouse endothelial cells showed a similar HDL uptake pattern in vivo indicating that the endothelium is one major site of HDL endocytosis and transcytosis.
Collapse
|
8
|
Röhrl C, Stangl H. HDL endocytosis and resecretion. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:1626-33. [PMID: 23939397 PMCID: PMC3795453 DOI: 10.1016/j.bbalip.2013.07.014] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 07/22/2013] [Accepted: 07/26/2013] [Indexed: 12/23/2022]
Abstract
HDL removes excess cholesterol from peripheral tissues and delivers it to the liver and steroidogenic tissues via selective lipid uptake without catabolism of the HDL particle itself. In addition, endocytosis of HDL holo-particles has been debated for nearly 40years. However, neither the connection between HDL endocytosis and selective lipid uptake, nor the physiological relevance of HDL uptake has been delineated clearly. This review will focus on HDL endocytosis and resecretion and its relation to cholesterol transfer. We will discuss the role of HDL endocytosis in maintaining cholesterol homeostasis in tissues and cell types involved in atherosclerosis, focusing on liver, macrophages and endothelium. We will critically summarize the current knowledge on the receptors mediating HDL endocytosis including SR-BI, F1-ATPase and CD36 and on intracellular HDL transport routes. Dependent on the tissue, HDL is either resecreted (retro-endocytosis) or degraded after endocytosis. Finally, findings on HDL transcytosis across the endothelial barrier will be summarized. We suggest that HDL endocytosis and resecretion is a rather redundant pathway under physiologic conditions. In case of disturbed lipid metabolism, however, HDL retro-endocytosis represents an alternative pathway that enables tissues to maintain cellular cholesterol homeostasis.
Collapse
Affiliation(s)
- Clemens Röhrl
- Department of Medical Chemistry, Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Herbert Stangl
- Department of Medical Chemistry, Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria.
| |
Collapse
|
9
|
Mechanisms regulating hepatic SR-BI expression and their impact on HDL metabolism. Atherosclerosis 2011; 217:299-307. [DOI: 10.1016/j.atherosclerosis.2011.05.036] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 05/11/2011] [Accepted: 05/26/2011] [Indexed: 11/22/2022]
|
10
|
Modulators of Protein Kinase C Affect SR-BI-Dependent HDL Lipid Uptake in Transfected HepG2 Cells. CHOLESTEROL 2011; 2011:687939. [PMID: 21490774 PMCID: PMC3065880 DOI: 10.1155/2011/687939] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 12/02/2010] [Indexed: 11/17/2022]
Abstract
SR-BI is a cell surface HDL receptor that mediates selective uptake of the lipid cargo of HDL, an important process in hepatocytes, driving reverse cholesterol transport from cells in the artery wall. To facilitate examination of factors that modulate SR-BI activity in hepatocytes, we have generated fluorescent protein-tagged versions of SR-BI that allow for facile monitoring of SR-BI protein levels and distribution in transfected cells. We show that deletion of the C-terminal cytosolic tail does not affect the distribution of SR-BI in HepG2 cells, nor is the C-terminal cytosolic tail required for SR-BI-mediated uptake of HDL lipids. We also demonstrate that the phorbol ester, PMA, increased, while protein kinase C inhibitors reduced SR-BI-mediated HDL lipid uptake in HepG2 cells. These data suggest that protein kinase C may modulate selective uptake of HDL lipids including cholesterol in hepatocytes, thereby influencing hepatic HDL cholesterol clearance and reverse cholesterol transport.
Collapse
|
11
|
Robichaud JC, van der Veen JN, Yao Z, Trigatti B, Vance DE. Hepatic uptake and metabolism of phosphatidylcholine associated with high density lipoproteins. Biochim Biophys Acta Gen Subj 2009; 1790:538-51. [PMID: 19250958 DOI: 10.1016/j.bbagen.2009.02.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Revised: 02/11/2009] [Accepted: 02/17/2009] [Indexed: 01/20/2023]
Abstract
BACKGROUND Phosphatidylcholine (PC) is the predominant phospholipid associated with high density lipoproteins (HDL). Although the hepatic uptake of cholesteryl esters from HDL is well characterized, much less is known about the fate of PC associated with HDL. Thus, we investigated the uptake and subsequent metabolism of HDL-PC in primary mouse hepatocytes. METHODS AND RESULTS The absence of scavenger receptor-BI resulted in a 30% decrease in cellular incorporation of [(3)H]PC whereas [(3)H]cholesteryl ether uptake was almost completely abolished. Although endocytosis is not involved in the uptake of cholesteryl esters from HDL, we demonstrate that HDL internalization accounts for 40% of HDL-PC uptake. Extracellular remodeling of HDL by secretory phospholipase A(2) significantly enhances HDL lipid uptake. HDL-PC taken up by hepatocytes is partially converted to triacylglycerols via PC-phospholipase C-mediated hydrolysis of PC and incorporation of diacylglycerol into triacylglycerol. The formation of triacylglycerol is independent of scavenger receptor-BI and occurs in extralysosomal compartments. CONCLUSIONS AND GENERAL SIGNIFICANCE These findings indicate that HDL-associated PC is incorporated into primary hepatocytes via a pathway that differs significantly from that of HDL-cholesteryl ester, and shows that HDL-PC is more than a framework molecule, as evidenced by its partial conversion to hepatic triacylglycerol.
Collapse
Affiliation(s)
- Julie C Robichaud
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | | | | | | | | |
Collapse
|
12
|
Xiao C, Watanabe T, Zhang Y, Trigatti B, Szeto L, Connelly PW, Marcovina S, Vaisar T, Heinecke JW, Lewis GF. Enhanced cellular uptake of remnant high-density lipoprotein particles: a mechanism for high-density lipoprotein lowering in insulin resistance and hypertriglyceridemia. Circ Res 2008; 103:159-66. [PMID: 18556574 DOI: 10.1161/circresaha.108.178756] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A low level of high-density lipoprotein (HDL) cholesterol is characteristic of insulin resistance and hypertriglyceridemia and likely contributes to the increased risk of cardiovascular disease associated with these conditions. One pathway involves enhanced clearance of lipolytically modified HDL particles, but the underlying mechanisms remain poorly understood. Here, we examine the effect of triglyceride enrichment and hepatic lipase hydrolysis on HDL binding, internalization, and degradation in cultured liver and kidney cells. Maximal binding of remnant HDL (HDL enriched with triglycerides followed by hepatic lipase hydrolysis), but not binding affinity, was markedly higher than native and triglyceride-rich HDL in both HepG2 cells and HEK293 cells. Compared with native and triglyceride-rich HDL, remnant HDL was internalized to a greater extent in both cell types and was more readily degraded in HEK293 cells. The increased binding of remnant HDL was not mediated by the low-density lipoprotein receptor or scavenger receptor class B type I (SR-BI), because enhanced remnant HDL binding was observed in low-density lipoprotein receptor-deficient cells with or without SR-BI overexpression. Disruption of cell surface heparan sulfate proteoglycans or blockage of apolipoprotein E-mediated lipoprotein binding also did not abolish the enhanced remnant HDL binding. Our observations indicate that remodeling of triglyceride-enriched HDL by hepatic lipase may result in enhanced binding, internalization, and degradation in tissues involved in HDL catabolism, contributing to rapid clearance and overall lowering of plasma HDL cholesterol in insulin resistance and hypertriglyceridemia.
Collapse
Affiliation(s)
- Changting Xiao
- Department of Medicine and Physiology, University of Toronto, Ontario, Canada
| | | | | | | | | | | | | | | | | | | |
Collapse
|