1
|
Hoekstra M, Zhang Z, Lindenburg PW, Van Eck M. Scavenger Receptor BI Deficiency in Mice Is Associated With Plasma Ceramide and Sphingomyelin Accumulation and a Reduced Cholesteryl Ester Fatty Acid Length and Unsaturation Degree. J Lipid Atheroscler 2024; 13:69-79. [PMID: 38299166 PMCID: PMC10825577 DOI: 10.12997/jla.2024.13.1.69] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/10/2023] [Accepted: 10/12/2023] [Indexed: 02/02/2024] Open
Abstract
Objective Scavenger receptor class B type I (SR-BI) is primarily known for its role in the selective uptake of cholesteryl esters (CEs) from high-density lipoproteins (HDLs). Here we investigated whether SR-BI deficiency is associated with other potentially relevant changes in the plasma lipidome than the established effect of HDL-cholesterol elevation. Methods Targeted ultra-high-performance liquid chromatography-tandem mass spectrometry was utilized to measure lipid species in plasma from female wild-type and SR-BI knockout mice. Results SR-BI deficiency was associated with a reduction in the average CE fatty acid length (-2%; p<0.001) and degree of CE fatty acid unsaturation (-18%; p<0.001) due to a relative shift from longer, polyunsaturated CE species CE (20:4), CE (20:5), and CE (22:6) towards the mono-unsaturated CE (18:1) species. Sphingomyelin (SM) levels were 64% higher (p<0.001) in SR-BI knockout mice without a parallel change in (lyso)phosphatidylcholine (LPC) concentrations, resulting in an increase in the SM/LPC ratio from 0.102±0.005 to 0.163±0.003 (p<0.001). In addition, lower LPC lengths (-5%; p<0.05) and fatty acid unsaturation degrees (-20%; p<0.01) were detected in SR-BI knockout mice. Furthermore, SR-BI deficiency was associated with a 4.7-fold increase (p<0.001) in total plasma ceramide (Cer) levels, with a marked >9-fold rise (p<0.001) in Cer (d18:1/24:1) concentrations. Conclusion We have shown that SR-BI deficiency in mice not only impacts the CE concentrations, length, and saturation index within the plasma compartment, but is also associated with plasma accumulation of several Cer and SM species that may contribute to the development of specific hematological and metabolic (disease) phenotypes previously detected in SR-BI knockout mice.
Collapse
Affiliation(s)
- Menno Hoekstra
- Division of Systems Pharmacology and Pharmacy, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
- Pharmacy Leiden, Leiden, The Netherlands
| | - Zhengzheng Zhang
- Metabolomics and Analytics Center, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - Peter W. Lindenburg
- Research Group Metabolomics, Faculty Science & Technology, University of Applied Sciences Leiden, Hogeschool Leiden, Leiden, The Netherlands
| | - Miranda Van Eck
- Division of Systems Pharmacology and Pharmacy, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
- Pharmacy Leiden, Leiden, The Netherlands
| |
Collapse
|
2
|
Lee SX, Heine M, Schlein C, Ramakrishnan R, Liu J, Belnavis G, Haimi I, Fischer AW, Ginsberg HN, Heeren J, Rinninger F, Haeusler RA. FoxO transcription factors are required for hepatic HDL cholesterol clearance. J Clin Invest 2018; 128:1615-1626. [PMID: 29408809 DOI: 10.1172/jci94230] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 02/01/2018] [Indexed: 12/15/2022] Open
Abstract
Insulin resistance and type 2 diabetes are associated with low levels of high-density lipoprotein cholesterol (HDL-C). The insulin-repressible FoxO transcription factors are potential mediators of the effect of insulin on HDL-C. FoxOs mediate a substantial portion of insulin-regulated transcription, and poor FoxO repression is thought to contribute to the excessive glucose production in diabetes. In this work, we show that mice with liver-specific triple FoxO knockout (L-FoxO1,3,4), which are known to have reduced hepatic glucose production, also have increased HDL-C. This was associated with decreased expression of the HDL-C clearance factors scavenger receptor class B type I (SR-BI) and hepatic lipase and defective selective uptake of HDL cholesteryl ester by the liver. The phenotype could be rescued by re-expression of SR-BI. These findings demonstrate that hepatic FoxOs are required for cholesterol homeostasis and HDL-mediated reverse cholesterol transport to the liver.
Collapse
Affiliation(s)
- Samuel X Lee
- Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Markus Heine
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Christian Schlein
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Rajasekhar Ramakrishnan
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Jing Liu
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Gabriella Belnavis
- Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Ido Haimi
- Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Alexander W Fischer
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Henry N Ginsberg
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Franz Rinninger
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, Hamburg, Germany.,Department of Internal Medicine III, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Rebecca A Haeusler
- Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York, USA.,Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, New York, New York, USA
| |
Collapse
|
3
|
Rein-Fischboeck L, Pohl R, Haberl EM, Weiss TS, Buechler C. The adaptor protein alpha-syntrophin is reduced in human non-alcoholic steatohepatitis but is unchanged in hepatocellular carcinoma. Exp Mol Pathol 2017; 103:204-209. [DOI: 10.1016/j.yexmp.2017.09.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 09/19/2017] [Indexed: 12/19/2022]
|
4
|
Pollard RD, Blesso CN, Zabalawi M, Fulp B, Gerelus M, Zhu X, Lyons EW, Nuradin N, Francone OL, Li XA, Sahoo D, Thomas MJ, Sorci-Thomas MG. Procollagen C-endopeptidase Enhancer Protein 2 (PCPE2) Reduces Atherosclerosis in Mice by Enhancing Scavenger Receptor Class B1 (SR-BI)-mediated High-density Lipoprotein (HDL)-Cholesteryl Ester Uptake. J Biol Chem 2015; 290:15496-15511. [PMID: 25947382 DOI: 10.1074/jbc.m115.646240] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Indexed: 01/28/2023] Open
Abstract
Studies in human populations have shown a significant correlation between procollagen C-endopeptidase enhancer protein 2 (PCPE2) single nucleotide polymorphisms and plasma HDL cholesterol concentrations. PCPE2, a 52-kDa glycoprotein located in the extracellular matrix, enhances the cleavage of C-terminal procollagen by bone morphogenetic protein 1 (BMP1). Our studies here focused on investigating the basis for the elevated concentration of enlarged plasma HDL in PCPE2-deficient mice to determine whether they protected against diet-induced atherosclerosis. PCPE2-deficient mice were crossed with LDL receptor-deficient mice to obtain LDLr(-/-), PCPE2(-/-) mice, which had elevated HDL levels compared with LDLr(-/-) mice with similar LDL concentrations. We found that LDLr(-/-), PCPE2(-/-) mice had significantly more neutral lipid and CD68+ infiltration in the aortic root than LDLr(-/-) mice. Surprisingly, in light of their elevated HDL levels, the extent of aortic lipid deposition in LDLr(-/-), PCPE2(-/-) mice was similar to that reported for LDLr(-/-), apoA-I(-/-) mice, which lack any apoA-I/HDL. Furthermore, LDLr(-/-), PCPE2(-/-) mice had reduced HDL apoA-I fractional clearance and macrophage to fecal reverse cholesterol transport rates compared with LDLr(-/-) mice, despite a 2-fold increase in liver SR-BI expression. PCPE2 was shown to enhance SR-BI function by increasing the rate of HDL-associated cholesteryl ester uptake, possibly by optimizing SR-BI localization and/or conformation. We conclude that PCPE2 is atheroprotective and an important component of the reverse cholesterol transport HDL system.
Collapse
Affiliation(s)
- Ricquita D Pollard
- Section of Molecular Medicine, Department of Internal Medicine and the Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27101
| | - Christopher N Blesso
- Department of Nutritional Sciences, University of Connecticut, Storrs, Connecticut 06268
| | - Manal Zabalawi
- Section of Molecular Medicine, Department of Internal Medicine and the Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27101
| | - Brian Fulp
- Section of Molecular Medicine, Department of Internal Medicine and the Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27101
| | - Mark Gerelus
- Section of Molecular Medicine, Department of Internal Medicine and the Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27101
| | - Xuewei Zhu
- Section of Molecular Medicine, Department of Internal Medicine and the Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27101
| | - Erica W Lyons
- Section of Molecular Medicine, Department of Internal Medicine and the Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27101
| | - Nebil Nuradin
- Department of Medicine and the Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Omar L Francone
- Shire Human Genetic Therapies, Lexington, Massachusetts 02421
| | - Xiang-An Li
- Department of Pediatrics, University of Kentucky, Lexington, Kentucky 40506
| | - Daisy Sahoo
- Department of Medicine and the Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Michael J Thomas
- Department of Medicine and the Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Mary G Sorci-Thomas
- Department of Medicine and the Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226.
| |
Collapse
|
5
|
Hebel T, Eisinger K, Neumeier M, Rein-Fischboeck L, Pohl R, Meier EM, Boettcher A, Froehner SC, Adams ME, Liebisch G, Krautbauer S, Buechler C. Lipid abnormalities in alpha/beta2-syntrophin null mice are independent from ABCA1. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:527-36. [PMID: 25625330 DOI: 10.1016/j.bbalip.2015.01.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 01/12/2015] [Accepted: 01/19/2015] [Indexed: 01/27/2023]
Abstract
The syntrophins alpha (SNTA) and beta 2 (SNTB2) are molecular adaptor proteins shown to stabilize ABCA1, an essential regulator of HDL cholesterol. Furthermore, SNTB2 is involved in glucose stimulated insulin release. Hyperglycemia and dyslipidemia are characteristic features of the metabolic syndrome, a serious public health problem with rising prevalence. Therefore, it is important to understand the role of the syntrophins herein. Mice deficient for both syntrophins (SNTA/B2-/-) have normal insulin and glucose tolerance, hepatic ABCA1 protein and cholesterol. When challenged with a HFD, wild type and SNTA/B2-/- mice have similar weight gain, adiposity, serum and liver triglycerides. Hepatic ABCA1, serum insulin and insulin sensitivity are normal while glucose tolerance is impaired. Liver cholesterol is reduced, and expression of SREBP2 and HMG-CoA-R is increased in the knockout mice. Scavenger receptor-BI (SR-BI) protein is strongly diminished in the liver of SNTA/B2-/- mice while SR-BI binding protein NHERF1 is not changed and PDZK1 is even induced. Knock-down of SNTA, SNTB2 or both has no effect on hepatocyte SR-BI and PDZK1 proteins. Further, SR-BI levels are not reduced in brown adipose tissue of SNTA/B2-/- mice excluding that syntrophins directly stabilize SR-BI. SR-BI stability is regulated by MAPK and phosphorylated ERK2 is induced in the liver of the knock-out mice. Blockage of ERK activity upregulates hepatocyte SR-BI showing that increased MAPK activity contributes to low SR-BI. Sphingomyelin which is well described to regulate cholesterol metabolism is reduced in the liver and serum of the knock-out mice while the size of serum lipoproteins is not affected. Current data exclude a major function of these syntrophins in ABCA1 activity and insulin release but suggest a role in regulating glucose uptake, ERK and SR-BI levels, and sphingomyelin metabolism in obesity.
Collapse
Affiliation(s)
- Tobias Hebel
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Kristina Eisinger
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Markus Neumeier
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Lisa Rein-Fischboeck
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Rebekka Pohl
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Elisabeth M Meier
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Alfred Boettcher
- Institute for Clinical Chemistry and Laboratory Medicine, Regensburg University Hospital, Regensburg, Germany
| | - Stanley C Froehner
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | - Marvin E Adams
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | - Gerhard Liebisch
- Institute for Clinical Chemistry and Laboratory Medicine, Regensburg University Hospital, Regensburg, Germany
| | - Sabrina Krautbauer
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Christa Buechler
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany.
| |
Collapse
|
6
|
Fruhwürth S, Kovacs WJ, Bittman R, Messner S, Röhrl C, Stangl H. Differential basolateral-apical distribution of scavenger receptor, class B, type I in cultured cells and the liver. Histochem Cell Biol 2014; 142:645-55. [PMID: 25059650 PMCID: PMC4241236 DOI: 10.1007/s00418-014-1251-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2014] [Indexed: 12/11/2022]
Abstract
The high-density lipoprotein (HDL) receptor, scavenger receptor class B, type I (SR-BI), mediates selective cholesteryl ester uptake into the liver, which finally results in cholesterol secretion into the bile. Despite several reports, the distribution of hepatic SR-BI between the sinusoidal and canalicular membranes is still under debate. We present immunohistological data using specific markers showing that the bulk of SR-BI is present in sinusoidal membranes and, to a lesser extent, in canalicular membranes in murine and human liver sections. In addition, SR-BI was detected in preparations of rat liver canalicular membranes. We also compared the in vivo findings to HepG2 cells, a widely used in vitro hepatocyte model. Interestingly, SR-BI was enriched in bile canalicular-like (BC-like) structures in polarized HepG2 cells, which were cultivated either conventionally to form a monolayer or in Matrigel to form three-dimensional structures. Fluorescently labeled HDL was transported into close proximity of BC-like structures, whereas HDL labeled with the fluorescent cholesterol analog BODIPY-cholesterol was clearly detected within these structures. Importantly, similarly to human and mouse liver, SR-BI was localized in basolateral membranes in three-dimensional liver microtissues from primary human liver cells. Our results demonstrate that SR-BI is highly enriched in sinusoidal membranes and is also found in canalicular membranes. There was no significant basolateral-apical redistribution of hepatic SR-BI in fasting and refeeding experiments in mice. Furthermore, in vitro studies in polarized HepG2 cells showed explicit differences as SR-BI was highly enriched in BC-like structures. These structures are, however, functional and accumulated HDL-derived cholesterol. Thus, biological relevant model systems should be employed when investigating SR-BI distribution in vitro.
Collapse
Affiliation(s)
- Stefanie Fruhwürth
- Center for Pathobiochemistry and Genetics, Department of Medical Chemistry, Medical University of Vienna, Währingerstraße 10, 1090 Vienna, Austria
| | - Werner J. Kovacs
- Institute of Molecular Health Sciences, Swiss Federal Institute of Technology Zurich (ETHZ), Zurich, Switzerland
| | - Robert Bittman
- Department of Chemistry and Biochemistry, Queens College of the City University of New York, Flushing, NY USA
| | | | - Clemens Röhrl
- Center for Pathobiochemistry and Genetics, Department of Medical Chemistry, Medical University of Vienna, Währingerstraße 10, 1090 Vienna, Austria
| | - Herbert Stangl
- Center for Pathobiochemistry and Genetics, Department of Medical Chemistry, Medical University of Vienna, Währingerstraße 10, 1090 Vienna, Austria
| |
Collapse
|