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Carneiro de Oliveira K, Wei Y, Repetti RL, Meth J, Majumder N, Sapkota A, Gusella GL, Rohatgi R. Tubular deficiency of ABCA1 augments cholesterol- and Na +-dependent effects on systemic blood pressure in male mice. Am J Physiol Renal Physiol 2024; 326:F265-F277. [PMID: 38153852 PMCID: PMC11207546 DOI: 10.1152/ajprenal.00154.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 10/31/2023] [Accepted: 11/17/2023] [Indexed: 12/30/2023] Open
Abstract
Dyslipidemia, with changes in plasma membrane (PM) composition, is associated with hypertension, while rising PM cholesterol induces Na+ channel activity. We hypothesize that ablation of renal tubular ABCA1, a cholesterol efflux protein, leads to cholesterol- and Na+-dependent changes in blood pressure (BP). Transgenic mice (TgPAX8rtTA;tetO-Cre/+) expressing a doxycycline (dox)-inducible CRE recombinase were bred with mice expressing floxed ABCA1 to generate renal tubules deficient in ABCA1 (ABCA1FF). Tail-cuff systolic BP (SBP) was measured in mice on specific diets. Immunoblotting was performed on whole and PM protein lysates of kidney from mice completing experimental diets. Cortical PM of ABCA1FF showed reduced ABCA1 (60 ± 28%; n = 10, P < 0.05) compared with wild-type littermates (WT; n = 9). Tail-cuff SBP of ABCA1FF (n = 11) was not only greater post dox, but also during cholesterol or high Na+ feeding (P < 0.05) compared with WT mice (n = 15). A Na+-deficient diet abolished the difference, while 6 wk of cholesterol diet raised SBP in ABCA1FF compared with mice before cholesterol feeding (P < 0.05). No difference in α-ENaC protein abundance was noted in kidney lysate; however, γ-ENaC increased in ABCA1FF mice versus WT mice. In kidney membranes, NKCC2 abundance was greater in ABCA1FF versus WT mice. Cortical lysates of ABCA1FF mouse kidneys expressed less renin and angiotensin I receptor than WT mouse kidneys. Furosemide injection induced a greater diuretic effect in ABCA1FF (n = 7; 45.2 ± 8.7 µL/g body wt) versus WT (n = 7; 33.1 ± 6.9 µL/g body wt; P < 0.05) but amiloride did not. Tubular ABCA1 deficiency induces cholesterol-dependent rise in SBP and modest Na+ sensitivity of SBP, which we speculate is partly related to Na+ transporters and channels.NEW & NOTEWORTHY Cholesterol has been linked to greater Na+ channel activity in kidney cells, which may predispose to systemic hypertension. We showed that when ABCA1, a protein that removes cholesterol from tissues, is ablated from mouse kidneys, systemic blood pressure is greater than normal mice. Dietary cholesterol further increases blood pressure in transgenic mice, whereas low dietary salt intake reduced blood pressure to that of normal mice. Thus, we speculate that diseases and pharmaceuticals that reduce renal ABCA1 expression, like diabetes and calcineurin inhibitors, respectively, contribute to the prominence of hypertension in their clinical presentation.
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Affiliation(s)
- Karin Carneiro de Oliveira
- Renal Section, Department of Medicine, James J. Peters Veterans Affairs Medical Center, Bronx, New York, United States
- Barbara T. Murphy Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Yuan Wei
- Renal Section, Department of Medicine, James J. Peters Veterans Affairs Medical Center, Bronx, New York, United States
- Barbara T. Murphy Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Robert L Repetti
- Renal Section, Department of Medicine, Northport Veterans Affairs Medical Center, Northport, New York, United States
- Division of Nephrology, Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, United States
| | - Jennifer Meth
- Renal Section, Department of Medicine, Northport Veterans Affairs Medical Center, Northport, New York, United States
| | - Nomrota Majumder
- Division of Nephrology, Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, United States
| | - Ananda Sapkota
- Division of Nephrology, Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, United States
| | - G Luca Gusella
- Barbara T. Murphy Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Rajeev Rohatgi
- Renal Section, Department of Medicine, James J. Peters Veterans Affairs Medical Center, Bronx, New York, United States
- Barbara T. Murphy Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States
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2
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Liu Y, Zhang C, Wang S, Hu Y, Jing J, Ye L, Jing R, Ding Z. Dependence of sperm structural and functional integrity on testicular calcineurin isoform PPP3R2 expression. J Mol Cell Biol 2021; 12:515-529. [PMID: 31900494 PMCID: PMC7493031 DOI: 10.1093/jmcb/mjz115] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 09/05/2019] [Accepted: 11/27/2019] [Indexed: 01/09/2023] Open
Abstract
After leaving the testis, mammalian sperm undergo a sequential maturation process in the epididymis followed by capacitation during their movement through the female reproductive tract. These phenotypic changes are associated with modification of protein phosphorylation and membrane remodeling, which is requisite for sperm to acquire forward motility and induce fertilization. However, the molecular mechanisms underlying sperm maturation and capacitation are still not fully understood. Herein, we show that PPP3R2, a testis-specific regulatory subunit of protein phosphatase 3 (an isoform of calcineurin in the testis), is essential for sperm maturation and capacitation. Knockout of Ppp3r2 in mice leads to male sterility due to sperm motility impairment and morphological defects. One very noteworthy change includes increases in sperm membrane stiffness. Moreover, PPP3R2 regulates sperm maturation and capacitation via (i) modulation of membrane diffusion barrier function at the annulus and (ii) facilitation of cholesterol efflux during sperm capacitation. Taken together, PPP3R2 plays a critical role in modulating cholesterol efflux and mediating the dynamic control of membrane remodeling during sperm maturation and capacitation.
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Affiliation(s)
- Yue Liu
- Department of Histology, Embryology, Genetics and Developmental Biology, Shanghai Key Laboratory for Reproductive Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Chujun Zhang
- Department of Clinical Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Shiyao Wang
- Department of Clinical Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yanqin Hu
- Department of Histology, Embryology, Genetics and Developmental Biology, Shanghai Key Laboratory for Reproductive Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jia Jing
- Department of Histology, Embryology, Genetics and Developmental Biology, Shanghai Key Laboratory for Reproductive Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Luyao Ye
- Department of Clinical Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Ran Jing
- Department of Clinical Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Zhide Ding
- Department of Histology, Embryology, Genetics and Developmental Biology, Shanghai Key Laboratory for Reproductive Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
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3
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Lake NJ, Taylor RL, Trahair H, Harikrishnan KN, Curran JE, Almeida M, Kulkarni H, Mukhamedova N, Hoang A, Low H, Murphy AJ, Johnson MP, Dyer TD, Mahaney MC, Göring HHH, Moses EK, Sviridov D, Blangero J, Jowett JBM, Bozaoglu K. TRAK2, a novel regulator of ABCA1 expression, cholesterol efflux and HDL biogenesis. Eur Heart J 2019; 38:3579-3587. [PMID: 28655204 DOI: 10.1093/eurheartj/ehx315] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 05/25/2017] [Indexed: 12/28/2022] Open
Abstract
Aims The recent failures of HDL-raising therapies have underscored our incomplete understanding of HDL biology. Therefore there is an urgent need to comprehensively investigate HDL metabolism to enable the development of effective HDL-centric therapies. To identify novel regulators of HDL metabolism, we performed a joint analysis of human genetic, transcriptomic, and plasma HDL-cholesterol (HDL-C) concentration data and identified a novel association between trafficking protein, kinesin binding 2 (TRAK2) and HDL-C concentration. Here we characterize the molecular basis of the novel association between TRAK2 and HDL-cholesterol concentration. Methods and results Analysis of lymphocyte transcriptomic data together with plasma HDL from the San Antonio Family Heart Study (n = 1240) revealed a significant negative correlation between TRAK2 mRNA levels and HDL-C concentration, HDL particle diameter and HDL subspecies heterogeneity. TRAK2 siRNA-mediated knockdown significantly increased cholesterol efflux to apolipoprotein A-I and isolated HDL from human macrophage (THP-1) and liver (HepG2) cells by increasing the mRNA and protein expression of the cholesterol transporter ATP-binding cassette, sub-family A member 1 (ABCA1). The effect of TRAK2 knockdown on cholesterol efflux was abolished in the absence of ABCA1, indicating that TRAK2 functions in an ABCA1-dependent efflux pathway. TRAK2 knockdown significantly increased liver X receptor (LXR) binding at the ABCA1 promoter, establishing TRAK2 as a regulator of LXR-mediated transcription of ABCA1. Conclusion We show, for the first time, that TRAK2 is a novel regulator of LXR-mediated ABCA1 expression, cholesterol efflux, and HDL biogenesis. TRAK2 may therefore be an important target in the development of anti-atherosclerotic therapies.
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Affiliation(s)
- Nicole J Lake
- Baker IDI Heart and Diabetes Institute, 75 Commercial Road, Melbourne, VIC 3004, Australia.,Murdoch Children's Research Institute, 50 Flemington Road, Parkville, VIC 3052, Australia
| | - Rachael L Taylor
- Baker IDI Heart and Diabetes Institute, 75 Commercial Road, Melbourne, VIC 3004, Australia
| | - Hugh Trahair
- Baker IDI Heart and Diabetes Institute, 75 Commercial Road, Melbourne, VIC 3004, Australia
| | - K N Harikrishnan
- Baker IDI Heart and Diabetes Institute, 75 Commercial Road, Melbourne, VIC 3004, Australia.,Department of Pathology, University of Melbourne, Grattan Street, Parkville, VIC 3010, Australia
| | - Joanne E Curran
- South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, One West University Blvd. Brownsville, Texas 78520, USA
| | - Marcio Almeida
- South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, One West University Blvd. Brownsville, Texas 78520, USA
| | - Hemant Kulkarni
- South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, One West University Blvd. Brownsville, Texas 78520, USA
| | - Nigora Mukhamedova
- Baker IDI Heart and Diabetes Institute, 75 Commercial Road, Melbourne, VIC 3004, Australia
| | - Anh Hoang
- Baker IDI Heart and Diabetes Institute, 75 Commercial Road, Melbourne, VIC 3004, Australia
| | - Hann Low
- Baker IDI Heart and Diabetes Institute, 75 Commercial Road, Melbourne, VIC 3004, Australia
| | - Andrew J Murphy
- Baker IDI Heart and Diabetes Institute, 75 Commercial Road, Melbourne, VIC 3004, Australia
| | - Matthew P Johnson
- South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, One West University Blvd. Brownsville, Texas 78520, USA
| | - Thomas D Dyer
- South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, One West University Blvd. Brownsville, Texas 78520, USA
| | - Michael C Mahaney
- South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, One West University Blvd. Brownsville, Texas 78520, USA
| | - Harald H H Göring
- South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, One West University Blvd. Brownsville, Texas 78520, USA
| | - Eric K Moses
- University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia.,Curtin University, Kent St, Bentley, WA 6102, Australia
| | - Dmitri Sviridov
- Baker IDI Heart and Diabetes Institute, 75 Commercial Road, Melbourne, VIC 3004, Australia
| | - John Blangero
- South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, One West University Blvd. Brownsville, Texas 78520, USA
| | - Jeremy B M Jowett
- Baker IDI Heart and Diabetes Institute, 75 Commercial Road, Melbourne, VIC 3004, Australia
| | - Kiymet Bozaoglu
- Baker IDI Heart and Diabetes Institute, 75 Commercial Road, Melbourne, VIC 3004, Australia.,Murdoch Children's Research Institute, 50 Flemington Road, Parkville, VIC 3052, Australia.,Department of Paediatrics, University of Melbourne, 50 Flemington Road, Parkville,VIC 3052, Australia
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Wu M, Liang C, Yu X, Song B, Yue Q, Zhai Y, Linck V, Cai Y, Niu N, Yang X, Zhang B, Wang Q, Zou L, Zhang S, Thai TL, Ma J, Sutliff RL, Zhang Z, Ma H. Lovastatin attenuates hypertension induced by renal tubule-specific knockout of ATP-binding cassette transporter A1, by inhibiting epithelial sodium channels. Br J Pharmacol 2019; 176:3695-3711. [PMID: 31222723 PMCID: PMC6715779 DOI: 10.1111/bph.14775] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 05/12/2019] [Accepted: 06/08/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND AND PURPOSE We have shown that cholesterol is synthesized in the principal cells of renal cortical collecting ducts (CCD) and stimulates the epithelial sodium channels (ENaC). Here we have determined whether lovastatin, a cholesterol synthesis inhibitor, can antagonize the hypertension induced by activated ENaC, following deletion of the cholesterol transporter (ATP-binding cassette transporter A1; ABCA1). EXPERIMENTAL APPROACH We selectively deleted ABCA1 in the principal cells of mouse CCD and used the cell-attached patch-clamp technique to record ENaC activity. Western blot and immunofluorescence staining were used to evaluate protein expression levels. Systolic BP was measured with the tail-cuff method. KEY RESULTS Specific deletion of ABCA1 elevated BP and ENaC single-channel activity in the principal cells of CCD in mice. These effects were antagonized by lovastatin. ABCA1 deletion elevated intracellular cholesterol levels, which was accompanied by elevated ROS, increased expression of serum/glucocorticoid regulated kinase 1 (Sgk1), phosphorylated neural precursor cell-expressed developmentally down-regulated protein 4-2 (Nedd4-2) and furin, along with shorten the primary cilium, and reduced ATP levels in urine. CONCLUSIONS AND IMPLICATIONS These data suggest that specific deletion of ABCA1 in principal cells increases BP by stimulating ENaC channels via a cholesterol-dependent pathway which induces several secondary responses associated with oxidative stress, activated Sgk1/Nedd4-2, increased furin expression, and reduced cilium-mediated release of ATP. As ABCA1 can be blocked by cyclosporine A, these results suggest further investigation of the possible use of statins to treat CsA-induced hypertension.
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Affiliation(s)
- Ming‐Ming Wu
- Departments of Cardiology and Clinic Pharmacy, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and TreatmentHarbin Medical University Cancer HospitalHarbinChina
- Department of PhysiologyEmory University School of MedicineAtlantaGeorgia
| | - Chen Liang
- Departments of Cardiology and Clinic Pharmacy, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and TreatmentHarbin Medical University Cancer HospitalHarbinChina
| | - Xiao‐Di Yu
- Departments of Cardiology and Clinic Pharmacy, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and TreatmentHarbin Medical University Cancer HospitalHarbinChina
| | - Bin‐Lin Song
- Departments of Cardiology and Clinic Pharmacy, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and TreatmentHarbin Medical University Cancer HospitalHarbinChina
- Department of PhysiologyEmory University School of MedicineAtlantaGeorgia
| | - Qiang Yue
- Department of PhysiologyEmory University School of MedicineAtlantaGeorgia
| | - Yu‐Jia Zhai
- Department of PhysiologyEmory University School of MedicineAtlantaGeorgia
| | - Valerie Linck
- Department of PhysiologyEmory University School of MedicineAtlantaGeorgia
| | - Yong‐Xu Cai
- Departments of Cardiology and Clinic Pharmacy, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and TreatmentHarbin Medical University Cancer HospitalHarbinChina
| | - Na Niu
- Departments of Cardiology and Clinic Pharmacy, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and TreatmentHarbin Medical University Cancer HospitalHarbinChina
| | - Xu Yang
- Departments of Cardiology and Clinic Pharmacy, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and TreatmentHarbin Medical University Cancer HospitalHarbinChina
| | - Bao‐Long Zhang
- Departments of Cardiology and Clinic Pharmacy, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and TreatmentHarbin Medical University Cancer HospitalHarbinChina
| | - Qiu‐Shi Wang
- Departments of Cardiology and Clinic Pharmacy, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and TreatmentHarbin Medical University Cancer HospitalHarbinChina
| | - Li Zou
- Department of PhysiologyEmory University School of MedicineAtlantaGeorgia
| | - Shuai Zhang
- Department of PhysiologyEmory University School of MedicineAtlantaGeorgia
| | - Tiffany L. Thai
- Department of PhysiologyEmory University School of MedicineAtlantaGeorgia
| | - Jing Ma
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of MedicineAtlanta Veterans Affairs Medical CenterDecaturGeorgia
| | - Roy L. Sutliff
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of MedicineAtlanta Veterans Affairs Medical CenterDecaturGeorgia
| | - Zhi‐Ren Zhang
- Departments of Cardiology and Clinic Pharmacy, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and TreatmentHarbin Medical University Cancer HospitalHarbinChina
| | - He‐Ping Ma
- Department of PhysiologyEmory University School of MedicineAtlantaGeorgia
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5
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Zhai YJ, Wu MM, Linck VA, Zou L, Yue Q, Wei SP, Song C, Zhang S, Williams CR, Song BL, Zhang ZR, Ma HP. Intracellular cholesterol stimulates ENaC by interacting with phosphatidylinositol‑4,5‑bisphosphate and mediates cyclosporine A-induced hypertension. Biochim Biophys Acta Mol Basis Dis 2019; 1865:1915-1924. [PMID: 31109455 DOI: 10.1016/j.bbadis.2018.08.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/04/2018] [Accepted: 08/19/2018] [Indexed: 12/31/2022]
Abstract
We have previously shown that blockade of ATP-binding cassette transporter A1 (ABCA1) with cyclosporine A (CsA) stimulates the epithelial sodium channel (ENaC) in cultured distal nephron cells. Here we show that CsA elevated systolic blood pressure in both wild-type and apolipoprotein E (ApoE) knockout (KO) mice to a similar level. The elevated systolic blood pressure was completely reversed by inhibition of cholesterol (Cho) synthesis with lovastatin. Inside-out patch-clamp data show that intracellular Cho stimulated ENaC in cultured distal nephron cells by interacting with phosphatidylinositol‑4,5‑bisphosphate (PIP2), an ENaC activator. Confocal microscopy data show that both α‑ENaC and PIP2 were localized in microvilli via a Cho-dependent mechanism. Deletion of membrane Cho reduced the levels of γ‑ENaC in the apical membrane. Reduced ABCA1 expression and elevated intracellular Cho were observed in old mice, compared to young mice. In parallel, cell-attached patch-clamp data from the split-open cortical collecting ducts (CCD) show that ENaC activity was significantly increased in old mice. These data suggest that elevation of intracellular Cho due to blockade of ABCA1 stimulates ENaC, which may contribute to CsA-induced hypertension. This study also implies that reduced ABCA1 expression may mediate age-related hypertension by increasing ENaC activity via elevation of intracellular Cho.
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Affiliation(s)
- Yu-Jia Zhai
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Ming-Ming Wu
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Cardiology, Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin 150081, China
| | - Valerie A Linck
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Li Zou
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Qiang Yue
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Shi-Peng Wei
- Department of Internal Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Chang Song
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Shuai Zhang
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Clintoria R Williams
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Bin-Lin Song
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Cardiology, Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin 150081, China
| | - Zhi-Ren Zhang
- Department of Cardiology, Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin 150081, China.
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA.
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6
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Macrophage lipid accumulation in the presence of immunosuppressive drugs mycophenolate mofetil and cyclosporin A. Inflamm Res 2019; 68:787-799. [PMID: 31227843 DOI: 10.1007/s00011-019-01262-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 06/10/2019] [Accepted: 06/12/2019] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE Mycophenolate (MPA) and cyclosporin A (CsA) are two immunosuppressive agents currently used for the treatment of autoimmune diseases. However, reports regarding their effects on inflammation and lipid handling are controversial. Here, we compare the effect of these two drugs on the expression of proteins involved in cholesterol handling and lipid accumulation in a macrophage cell system utilizing M0, M1 and M2 human macrophages and in murine bone marrow-derived macrophages (BMDM). METHODS Differentiated M0, M1 and M2 subsets of THP-1 human macrophages were subjected to various concentrations of either MPA or CsA. Expression of proteins involved in reverse cholesterol transport (ABCA1 and 27-hydroxylase) and scavenger receptors, responsible for uptake of modified lipids (CD36, ScR-A1, CXCL16 and LOX-1), were evaluated by real-time PCR and confirmed with Western blot. DiI-oxidized LDL internalization assay was used to assess foam cell formation. The influence of MPA was also evaluated in BMDM obtained from atherosclerosis-prone transgenic mice, ApoE-/- and ApoE-/-Fas-/-. RESULTS In M0 macrophages, MPA increased expression of ABCA1 and CXCL16 in a concentration-dependent manner. In M1 THP-1 macrophages, MPA caused a significant increase of 27-hydroxylase mRNA and CD36 and SR-A1 receptor mRNAs. Exposure of M2 macrophages to MPA also stimulated expression of 27-hydroxylase, while downregulating all evaluated scavenger receptors. In contrast, CsA had no impact on cholesterol efflux in M0 and M1 macrophages, but significantly augmented expression of ABCA1 and 27-hydroxylase in M2 macrophages. CsA significantly increased expression of the LOX1 receptor in naïve macrophages, downregulated expression of CD36 and SR-A1 in the M1 subpopulation and upregulated expression of all evaluated scavenger receptors. However, CsA enhanced foam cell transformation in M0 and M2 macrophages, while MPA had no effect on foam cell formation unless used at a high concentration in the M2 subtype. CONCLUSIONS Our results clearly underline the importance of further evaluation of the effects of these drugs when used in atherosclerosis-prone patients with autoimmune or renal disease.
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Hu J, Yang Q, Chen Z, Liang W, Feng J, Ding G. Small GTPase Arf6 regulates diabetes-induced cholesterol accumulation in podocytes. J Cell Physiol 2019; 234:23559-23570. [PMID: 31206670 DOI: 10.1002/jcp.28924] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/19/2019] [Accepted: 05/20/2019] [Indexed: 12/29/2022]
Abstract
Podocyte injury is a critical factor for the initiation and progression of diabetic kidney disease (DKD). However, the underlying mechanisms of podocyte injury in DKD have not been completely elucidated. Studies suggested that intracellular cholesterol accumulation was correlated with podocyte injury, but the cause of podocyte cholesterol disorders in DKD are still unknown. ADP-ribosylation factor 6 (Arf6) is a small GTPase with pleiotropic effects and has previously been shown to regulate ATP-binding cassette transporter 1 (ABCA1) recycling, and thus, cholesterol homeostasis. However, Arf6 involvement in cholesterol metabolism in podocytes is scarce. To investigate the role of Arf6 in cholesterol modulation in podocytes, the effect of Arf6 on the regulation of the cholesterol transporter ABCA1 was studied in podocytes in vivo and in vitro. Intracellular cholesterol accumulation was significantly increased in podocytes from streptozotocin-induced diabetic rats and that hyperglycemia downregulated the expression of Arf6. Arf6 knockdown could cause ABCA1 recycling disorders, and thus, further aggravate cholesterol accumulation in podocytes under high-glucose (HG) conditions. Our results demonstrate that HG-induced cholesterol accumulation and cellular injury in podocytes may be related to the recycling disorder of ABCA1 caused by the downexpression of Arf6 in DKD.
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Affiliation(s)
- Jijia Hu
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Qian Yang
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zhaowei Chen
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Wei Liang
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Jun Feng
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Guohua Ding
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, China
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8
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Zhang T, Wang Q, Wang Y, Wang J, Su Y, Wang F, Wang G. AIBP and APOA-I synergistically inhibit intestinal tumor growth and metastasis by promoting cholesterol efflux. J Transl Med 2019; 17:161. [PMID: 31101050 PMCID: PMC6524272 DOI: 10.1186/s12967-019-1910-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 05/07/2019] [Indexed: 12/24/2022] Open
Abstract
Background The roles played by cholesterol in cancer development and progression represent a popular field in the cancer community. High cholesterol levels are positively correlated with the risk of various types of cancer. APOA-I binding protein (AIBP) promotes the reverse cholesterol transport pathway (RCT) in cooperation with Apolipoprotein A-I (APOA-I) or high-density lipoprotein cholesterol. However, the combined effect of AIBP and APOA-I on intestinal tumor cells is still unclear. Methods Immunohistochemistry, western blot and qPCR were performed to investigate the expression of AIBP and APOA-I in intestinal tumor tissues and cell lines. The anti-tumor activity of AIBP and APOA-I was evaluated by overexpression or recombinant protein treatment. Cholesterol efflux and localization of lipid raft-related proteins were analyzed by a cholesterol efflux assay and lipid raft fraction assay, respectively. Results Here, we reported that both AIBP expression and APOA-I expression were associated with the degree of malignancy in intestinal tumors. Co-overexpression of AIBP and APOA-I more potently inhibited colon cancer cell-mediated tumor growth and metastasis compared to overexpression of each protein individually. Additionally, the recombinant fusion proteins of AIBP and APOA-I exhibited a significant therapeutic effect on tumor growth in Apcmin/+ mice as an inherited intestinal tumor model. The synergistic effect of the two proteins inhibited colon cancer cell migration, invasion and tumor-induced angiogenesis by promoting cholesterol efflux, reducing the membrane raft content, and eventually disrupting the proper localization of migration- and invasion-related proteins on the membrane raft. Moreover, cyclosporine A, a cholesterol efflux inhibitor, rescued the inhibitory effect induced by the combination of AIBP and APOA-I. Conclusions These results indicate that the combination of APOA-I and AIBP has an obvious anticancer effect on colorectal cancer by promoting cholesterol efflux. Electronic supplementary material The online version of this article (10.1186/s12967-019-1910-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tao Zhang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, China.,Institute of Combined Injury, State Key Laboratory of Trauma, Burn and Combined Injury, Third Military Medical University, Chongqing, China
| | - Qilong Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, China
| | - Yeqi Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, China
| | - Junping Wang
- Institute of Combined Injury, State Key Laboratory of Trauma, Burn and Combined Injury, Third Military Medical University, Chongqing, China
| | - Yongping Su
- Institute of Combined Injury, State Key Laboratory of Trauma, Burn and Combined Injury, Third Military Medical University, Chongqing, China
| | - Fengchao Wang
- Institute of Combined Injury, State Key Laboratory of Trauma, Burn and Combined Injury, Third Military Medical University, Chongqing, China.
| | - Guixue Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, China.
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9
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PMP22 Regulates Cholesterol Trafficking and ABCA1-Mediated Cholesterol Efflux. J Neurosci 2019; 39:5404-5418. [PMID: 31061090 DOI: 10.1523/jneurosci.2942-18.2019] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 04/22/2019] [Accepted: 04/26/2019] [Indexed: 12/21/2022] Open
Abstract
The absence of functional peripheral myelin protein 22 (PMP22) is associated with shortened lifespan in rodents and severe peripheral nerve myelin abnormalities in several species including humans. Schwann cells and nerves from PMP22 knock-out (KO) mice show deranged cholesterol distribution and aberrant lipid raft morphology, supporting an unrecognized role for PMP22 in cellular lipid metabolism. To examine the mechanisms underlying these abnormalities, we studied Schwann cells and nerves from male and female PMP22 KO mice. Whole-cell current-clamp recordings in cultured Schwann cells revealed increased membrane capacitance and decreased membrane resistance in the absence of PMP22, which was consistent with a reduction in membrane cholesterol. Nerves from PMP22-deficient mice contained abnormal lipid droplets, with both mRNA and protein levels of apolipoprotein E (apoE) and ATP-binding cassette transporter A1 (ABCA1) being highly upregulated. Despite the upregulation of ABCA1 and apoE, the absence of PMP22 resulted in reduced localization of the transporter to the cell membrane and diminished secretion of apoE. The absence of PMP22 also impaired ABCA1-mediated cholesterol efflux capacity. In nerves from ABCA1 KO mice, the expression of PMP22 was significantly elevated and the subcellular processing of the overproduced protein was aberrant. In wild-type samples, double immunolabeling identified overlapping distribution of PMP22 and ABCA1 at the Schwann cell plasma membrane and the two proteins were coimmunoprecipitated from Schwann cell and nerve lysates. Together, these results reveal a novel role for PMP22 in regulating lipid metabolism and cholesterol trafficking through functional interaction with the cholesterol efflux regulatory protein ABCA1.SIGNIFICANCE STATEMENT Understanding the subcellular events that underlie abnormal myelin formation in hereditary neuropathies is critical for advancing therapy development. Peripheral myelin protein 22 (PMP22) is an essential peripheral myelin protein because its genetic abnormalities account for ∼80% of hereditary neuropathies. Here, we demonstrate that in the absence of PMP22, the cellular and electrophysiological properties of the Schwann cells' plasma membrane are altered and cholesterol trafficking and lipid homeostasis are perturbed. The molecular mechanisms for these abnormalities involve a functional interplay among PMP22, cholesterol, apolipoprotein E, and the major cholesterol-efflux transporter protein ATP-binding cassette transporter A1 (ABCA1). These findings establish a critical role for PMP22 in the maintenance of cholesterol homeostasis in Schwann cells.
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10
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Rodriguez-Agudo D, Malacrida L, Kakiyama G, Sparrer T, Fortes C, Maceyka M, Subler MA, Windle JJ, Gratton E, Pandak WM, Gil G. StarD5: an ER stress protein regulates plasma membrane and intracellular cholesterol homeostasis. J Lipid Res 2019; 60:1087-1098. [PMID: 31015253 DOI: 10.1194/jlr.m091967] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/08/2019] [Indexed: 01/01/2023] Open
Abstract
How plasma membrane (PM) cholesterol is controlled is poorly understood. Ablation of the gene encoding the ER stress steroidogenic acute regulatory-related lipid transfer domain (StarD)5 leads to a decrease in PM cholesterol content, a decrease in cholesterol efflux, and an increase in intracellular neutral lipid accumulation in macrophages, the major cell type that expresses StarD5. ER stress increases StarD5 expression in mouse hepatocytes, which results in an increase in accessible PM cholesterol in WT but not in StarD5-/- hepatocytes. StarD5-/- mice store higher levels of cholesterol and triglycerides, which leads to altered expression of cholesterol-regulated genes. In vitro, a recombinant GST-StarD5 protein transfers cholesterol between synthetic liposomes. StarD5 overexpression leads to a marked increase in PM cholesterol. Phasor analysis of 6-dodecanoyl-2-dimethylaminonaphthalene fluorescence lifetime imaging microscopy data revealed an increase in PM fluidity in StarD5-/- macrophages. Taken together, these studies show that StarD5 is a stress-responsive protein that regulates PM cholesterol and intracellular cholesterol homeostasis.
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Affiliation(s)
- Daniel Rodriguez-Agudo
- Departments of Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298.,McGuire Veterans Affairs Medical Center, Richmond, VA 23248
| | - Leonel Malacrida
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California at Irvine, Irvine, CA 92697.,Area de Investigación Respiratoria, Departamento de Fisiopatologia, Hospital de Clinicas, Facultad de Medicina, Universidad de la Republica, Montevideo, Uruguay
| | - Genta Kakiyama
- Departments of Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298.,McGuire Veterans Affairs Medical Center, Richmond, VA 23248
| | - Tavis Sparrer
- Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA 23298
| | - Carolina Fortes
- Departments of Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298.,Departmento de Biologia Molecular y Bioquimica, Universidad de Malaga, Malaga, Spain
| | - Michael Maceyka
- Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA 23298.,Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, VA 23298
| | - Mark A Subler
- Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298
| | - Jolene J Windle
- Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, VA 23298.,Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California at Irvine, Irvine, CA 92697
| | - William M Pandak
- Departments of Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298 .,McGuire Veterans Affairs Medical Center, Richmond, VA 23248
| | - Gregorio Gil
- Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA 23298 .,Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, VA 23298
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11
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Lee EH, Kim S, Choi MS, Park SM, Moon KS, Yoon S, Oh JH. Inhibition of PPARα target genes during cyclosporine A-induced nephrotoxicity and hepatotoxicity. Mol Cell Toxicol 2019. [DOI: 10.1007/s13273-019-0022-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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12
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Shinohara M, Shinohara M, Zhao J, Fu Y, Liu CC, Kanekiyo T, Bu G. 5-HT3 Antagonist Ondansetron Increases apoE Secretion by Modulating the LXR-ABCA1 Pathway. Int J Mol Sci 2019; 20:ijms20061488. [PMID: 30934555 PMCID: PMC6471172 DOI: 10.3390/ijms20061488] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/10/2019] [Accepted: 03/21/2019] [Indexed: 12/20/2022] Open
Abstract
Apolipoprotein E (apoE) is linked to the risk for Alzheimer’s disease (AD) and thus has been suggested to be an important therapeutic target. In our drug screening effort, we identified Ondansetron (OS), an FDA-approved 5-HT3 antagonist, as an apoE-modulating drug. OS at low micromolar concentrations significantly increased apoE secretion from immortalized astrocytes and primary astrocytes derived from apoE3 and apoE4-targeted replacement mice without generating cellular toxicity. Other 5-HT3 antagonists also had similar effects as OS, though their effects were milder and required higher concentrations. Antagonists for other 5-HT receptors did not increase apoE secretion. OS also increased mRNA and protein levels of the ATB-binding cassette protein A1 (ABCA1), which is involved in lipidation and secretion of apoE. Accordingly, OS increased high molecular weight apoE. Moreover, the liver X receptor (LXR) and ABCA1 antagonists blocked the OS-induced increase of apoE secretion, indicating that the LXR-ABCA1 pathway is involved in the OS-mediated facilitation of apoE secretion from astrocytes. The effects of OS on apoE and ABCA1 were also observed in human astrocytes derived from induced pluripotent stem cells (iPSC) carrying the APOE ε3/ε3 and APOE ε4/ε4 genotypes. Oral administration of OS at clinically-relevant doses affected apoE levels in the liver, though the effects in the brain were not observed. Collectively, though further studies are needed to probe its effects in vivo, OS could be a potential therapeutic drug for AD by modulating poE metabolism through the LXR-ABCA1 pathway.
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Affiliation(s)
- Motoko Shinohara
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.
- Department of Aging Neurobiology, National Center for Geriatrics and Gerontology, Aichi 474-8511, Japan.
| | - Mitsuru Shinohara
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.
- Department of Aging Neurobiology, National Center for Geriatrics and Gerontology, Aichi 474-8511, Japan.
| | - Jing Zhao
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.
| | - Yuan Fu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.
| | - Chia-Chen Liu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.
| | - Takahisa Kanekiyo
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.
- Neuroscience Graduate Program, Mayo Clinic, Jacksonville, FL 32224, USA.
| | - Guojun Bu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.
- Neuroscience Graduate Program, Mayo Clinic, Jacksonville, FL 32224, USA.
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13
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Oldoni F, van Capelleveen JC, Dalila N, Wolters JC, Heeren J, Sinke RJ, Hui DY, Dallinga-Thie GM, Frikke-Schmidt R, Hovingh KG, van de Sluis B, Tybjærg-Hansen A, Kuivenhoven JA. Naturally Occurring Variants in LRP1 (Low-Density Lipoprotein Receptor-Related Protein 1) Affect HDL (High-Density Lipoprotein) Metabolism Through ABCA1 (ATP-Binding Cassette A1) and SR-B1 (Scavenger Receptor Class B Type 1) in Humans. Arterioscler Thromb Vasc Biol 2018; 38:1440-1453. [PMID: 29853565 PMCID: PMC6023722 DOI: 10.1161/atvbaha.117.310309] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 05/07/2018] [Indexed: 12/14/2022]
Abstract
Supplemental Digital Content is available in the text. Objective— Studies into the role of LRP1 (low-density lipoprotein receptor–related protein 1) in human lipid metabolism are scarce. Although it is known that a common variant in LRP1 (rs116133520) is significantly associated with HDL-C (high-density lipoprotein cholesterol), the mechanism underlying this observation is unclear. In this study, we set out to study the functional effects of 2 rare LRP1 variants identified in subjects with extremely low HDL-C levels. Approach and Results— In 2 subjects with HDL-C below the first percentile for age and sex and moderately elevated triglycerides, we identified 2 rare variants in LRP1: p.Val3244Ile and p.Glu3983Asp. Both variants decrease LRP1 expression and stability. We show in a series of translational experiments that these variants culminate in reduced trafficking of ABCA1 (ATP-binding cassette A1) to the cell membrane. This is accompanied by an increase in cell surface expression of SR-B1 (scavenger receptor class B type 1). Combined these effects may contribute to low HDL-C levels in our study subjects. Supporting these findings, we provide epidemiological evidence that rs116133520 is associated with apo (apolipoprotein) A1 but not with apoB levels. Conclusions— This study provides the first evidence that rare variants in LRP1 are associated with changes in human lipid metabolism. Specifically, this study shows that LRP1 may affect HDL metabolism by virtue of its effect on both ABCA1 and SR-B1.
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Affiliation(s)
- Federico Oldoni
- From the Department of Pediatrics, Section of Molecular Genetics, University Medical Centre Groningen, University of Groningen, The Netherlands (F.O., J.C.W., B.v.d.S., J.A.K.)
| | | | - Nawar Dalila
- Department of Clinical Biochemistry, Rigshospitalet (N.D., R.F.-S., A.T.-H.)
| | - Justina C Wolters
- From the Department of Pediatrics, Section of Molecular Genetics, University Medical Centre Groningen, University of Groningen, The Netherlands (F.O., J.C.W., B.v.d.S., J.A.K.)
| | - Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Germany (J.H.)
| | - Richard J Sinke
- Department of Genetics, University Medical Centre Groningen, The Netherlands (R.J.S.)
| | - David Y Hui
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Institute, University of Cincinnati College of Medicine, OH (D.Y.H.)
| | - Geesje M Dallinga-Thie
- Department of Vascular Medicine (J.C.v.C., G.M.D.-T., K.G.H.).,Department Experimental Vascular Medicine (G.M.D.-T.), Academic Medical Center, Amsterdam, The Netherlands
| | - Ruth Frikke-Schmidt
- Department of Clinical Biochemistry, Rigshospitalet (N.D., R.F.-S., A.T.-H.)
| | - Kees G Hovingh
- Department of Vascular Medicine (J.C.v.C., G.M.D.-T., K.G.H.)
| | - Bart van de Sluis
- From the Department of Pediatrics, Section of Molecular Genetics, University Medical Centre Groningen, University of Groningen, The Netherlands (F.O., J.C.W., B.v.d.S., J.A.K.)
| | - Anne Tybjærg-Hansen
- Department of Clinical Biochemistry, Rigshospitalet (N.D., R.F.-S., A.T.-H.).,Copenhagen City Heart Study, Frederiksberg Hospital (A.T.-H.), Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Jan Albert Kuivenhoven
- From the Department of Pediatrics, Section of Molecular Genetics, University Medical Centre Groningen, University of Groningen, The Netherlands (F.O., J.C.W., B.v.d.S., J.A.K.)
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14
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Abstract
PURPOSE OF REVIEW Cholesterol metabolism is increasingly recognized in inflammatory diseases including transplantation. This review discusses the mechanistic underpinnings that tie macrophage cholesterol efflux capacity (CEC) of high-density lipoprotein (HDL) to chronic rejection in transplanted patients. RECENT FINDINGS Animal studies suggest that administration of apolipoprotein A-I, the main protein constituent of HDL, can prevent transplant arteriosclerosis. apoA-I administration increases CEC of HDL. In patients with cardiac allograft vasculopathy (CAV), decreased CEC has been associated with poorer survival. In addition, reduced CEC in recipients, pretransplant, has been associated with the development of CAV and renal allograft survival. SUMMARY These recent findings raise the hypothesis that increasing cholesterol efflux may prevent chronic rejection and improve allograft survival after transplant. Reconstituted HDL significantly increases CEC and is currently in clinical development for traditional atherosclerosis. Clinical trials of reconstituted HDL administration in transplantation should be performed.
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15
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Aziz MM, Eid NI, Nada AS, Amin NED, Ain-Shoka AA. Possible protective effect of the algae spirulina against nephrotoxicity induced by cyclosporine A and/or gamma radiation in rats. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:9060-9070. [PMID: 29333572 DOI: 10.1007/s11356-017-1146-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 12/26/2017] [Indexed: 06/07/2023]
Abstract
The present study was conducted to evaluate the possible protective role of the algae spirulina (Sp) against nephrotoxicity and oxidative stress which are the main secondary effects induced by the immunosuppressant drug CSA and/or ionizing radiation. In this study, male rats were given Sp (1 g/kg) either for 15 days before irradiation (6.5 Gy) or 5 days before and 10 days concomitant with CSA (25 mg/kg). Markers used to assess renal injury included serum creatinine, urea, glucose, albumin, protein, and lipid profile as well as kidney content of reduced glutathione (GSH); lipid peroxidation (thiobarbituric acid reactive substances (TBARS)); nitrite and superoxide dismutase (SOD) activity. In addition, some trace elements (Zn and Mg) were estimated in kidney. Apoptosis was assessed by immunohistochemical estimation of caspase-3 expression in addition to histopathological examination. Results revealed that gamma radiation and/or CSA induced elevation in urea, creatinine, lipids, and glucose while decreasing albumin and protein levels. There was a noticeable increase in kidney content of GSH, TBARS, and nitrite. Meanwhile, profound decrease in kidney SOD activity was observed. Treatment with Sp significantly reversed the changes induced by CSA and/or gamma radiation in renal function tests. Spirulina also ameliorated kidney oxidative stress through decreasing GSH, TBARS, and nitrite kidney content while increasing SOD activity. Histopathological examination further confirmed Sp protective efficacy. Moreover, kidney caspase-3 expression that was triggered by CSA and/or gamma radiation was decreased. In conclusion, spirulina can be regarded as a promising renoprotective natural agent against renal injury induced by CSA and/or gamma radiation.
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Affiliation(s)
- Maha M Aziz
- Department of Drug Radiation Research, National Center for Radiation Research and Technology, Atomic Energy Authority, Nasr City, PO Box 29, Cairo, Egypt.
| | - Nihad I Eid
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Giza, Egypt
| | - Ahmed S Nada
- Department of Drug Radiation Research, National Center for Radiation Research and Technology, Atomic Energy Authority, Nasr City, PO Box 29, Cairo, Egypt
| | - Nour El-Din Amin
- Department of Drug Radiation Research, National Center for Radiation Research and Technology, Atomic Energy Authority, Nasr City, PO Box 29, Cairo, Egypt
| | - Afaf A Ain-Shoka
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Giza, Egypt
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16
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Phillips MC. Is ABCA1 a lipid transfer protein? J Lipid Res 2018; 59:749-763. [PMID: 29305383 DOI: 10.1194/jlr.r082313] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/02/2018] [Indexed: 12/16/2022] Open
Abstract
ABCA1 functions as a lipid transporter because it mediates the transfer of cellular phospholipid (PL) and free (unesterified) cholesterol (FC) to apoA-I and related proteins present in the extracellular medium. ABCA1 is a membrane PL translocase and its enzymatic activity leads to transfer of PL molecules from the cytoplasmic leaflet to the exofacial leaflet of a cell plasma membrane (PM). The presence of active ABCA1 in the PM promotes binding of apoA-I to the cell surface. About 10% of this bound apoA-I interacts directly with ABCA1 and stabilizes the transporter. Most of the pool of cell surface-associated apoA-I is bound to lipid domains in the PM that are created by the activity of ABCA1. The amphipathic α-helices in apoA-I confer detergent-like properties on the protein enabling it to solubilize PL and FC in these membrane domains to create a heterogeneous population of discoidal nascent HDL particles. This review focuses on current understanding of the structure-function relationships of human ABCA1 and the molecular mechanisms underlying HDL particle production.
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Affiliation(s)
- Michael C Phillips
- Division of Translational Medicine and Human Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-5158
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17
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Jadhav PD, Shim YY, Reaney MJT. Affinity binding of chicken apolipoprotein A1 to a novel flax orbitide (linusorb). RSC Adv 2018; 8:17702-17709. [PMID: 35542099 PMCID: PMC9080508 DOI: 10.1039/c8ra01757c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 04/14/2020] [Accepted: 04/18/2018] [Indexed: 01/09/2023] Open
Abstract
Bioactive orbitides (linusorbs, LOs) from flaxseed (Linum usitatissimum L.) were ligated through methionine with resin to form an affinity column. The affinity resin was characterized using elemental analysis and the resin bound 70% of its weight in LOs. Chicken serum was passed over the column and washed to remove non-binding materials. The column was eluted with unbound orbitide to competitively release bound protein. A single 28 kDa protein was found in the affinity binding pool. The protein MW and sequence were identical to apolipoprotein A1 (Apo A1), a major serum protein. Its role includes reverse cholesterol transport and cholesterol efflux. The affinity technique allowed convenient and rapid isolation of Apo A1 with a recyclable affinity column. LO binding to a cholesterol carrier molecule might also help us to understand the mechanism of action of LOs in health and the biological activity of flaxseed products. Bioactive orbitides (linusorbs) from flaxseed (Linum usitatissimum L.) were ligated through methionine with resin to form an affinity column that selectively binds chicken apolipoprotein A1 from chicken serum.![]()
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Affiliation(s)
| | - Youn Young Shim
- Department of Plant Sciences
- University of Saskatchewan
- Saskatoon
- Canada
- Guangdong Saskatchewan Oilseed Joint Laboratory
| | - Martin J. T. Reaney
- Department of Plant Sciences
- University of Saskatchewan
- Saskatoon
- Canada
- Guangdong Saskatchewan Oilseed Joint Laboratory
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18
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Lepist EI, Ray AS. Beyond drug-drug interactions: effects of transporter inhibition on endobiotics, nutrients and toxins. Expert Opin Drug Metab Toxicol 2017; 13:1075-1087. [PMID: 28847160 DOI: 10.1080/17425255.2017.1372425] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Membrane transport proteins play a central role in regulating the disposition of endobiotics, dietary nutrients and environmental toxins. The inhibition of transporters by drugs has potential physiologic consequences. The full extent of the effect of drugs on the function of transporters is poorly understood because only a small subset of the hundreds of transporters expressed in humans - primarily those mediating the rate-determining step in the elimination of specific drugs - are assessed during clinical development. Areas covered: We provide a comprehensive overview of literature reports implicating the inhibition of transporters as the mechanism for off-target effects of drugs. Expert opinion: Transporter inhibition, the mechanism of action of many marketed drugs, appears to play an underappreciated role in a number of side effects including vitamin deficiency, edema, dyslipidemia, cholestasis and gout. Cell systems more broadly expressing transporter networks and methods like unbiased metabolomics should be incorporated into the screening paradigm to expand our understanding of the impact of drugs on the physiologic function of transporters and to allow for these effects to be taken into account in drug discovery and clinical practice.
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Affiliation(s)
- Eve-Irene Lepist
- a Departments of Drug Metabolism , Gilead Sciences, Inc ., Foster City , CA , USA
| | - Adrian S Ray
- b Clinical Research , Gilead Sciences, Inc ., Foster City , CA , USA
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19
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Sengupta MB, Saha S, Mohanty PK, Mukhopadhyay KK, Mukhopadhyay D. Increased expression of ApoA1 after neuronal injury may be beneficial for healing. Mol Cell Biochem 2016; 424:45-55. [PMID: 27734225 DOI: 10.1007/s11010-016-2841-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 10/06/2016] [Indexed: 01/24/2023]
Abstract
ApoA1 is a player in reverse cholesterol transport that initiates multiple cellular pathways on binding to its receptor ABCA1. Its relation to neuronal injury is however unclear. We found ApoA1 to be increasingly abundant at a later time point in the secondary phase of traumatic spinal cord injury. In a cellular injury model of neuroblastoma, ApoA1 showed an initial diminished expression after infliction of injury, which sharply increased thereafter. Subsequently, ApoA1 was shown to alter wound healing dynamics in neuroblastoma injury model. It was observed that an initial lag in scratch wound closure was followed by rapid healing in the ApoA1 treatment group. Activation of ERK pathway and Actin polymerisation by ApoA1 corroborated its role in healing after neuronal injury. We propose that ApoA1 is increasingly expressed and secreted as a delayed response to neuronal injury, and this is a self-protecting mechanism of the injured system.
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Affiliation(s)
- Mohor B Sengupta
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata, 700064, India
| | - Suparna Saha
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata, 700064, India
| | - Pradeep K Mohanty
- Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata, 700064, India
| | - Kiran K Mukhopadhyay
- Department of Orthopaedic Surgery, Nil Ratan Sircar Medical College and Hospital, 138 AJC Bose Road, Kolkata, 700014, India
| | - Debashis Mukhopadhyay
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata, 700064, India.
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20
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Eicosapentaenoic acid membrane incorporation impairs ABCA1-dependent cholesterol efflux via a protein kinase A signaling pathway in primary human macrophages. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:331-41. [DOI: 10.1016/j.bbalip.2016.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 01/04/2016] [Accepted: 01/07/2016] [Indexed: 11/22/2022]
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21
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Zhao W, Prijic S, Urban BC, Tisza MJ, Zuo Y, Li L, Tan Z, Chen X, Mani SA, Chang JT. Candidate Antimetastasis Drugs Suppress the Metastatic Capacity of Breast Cancer Cells by Reducing Membrane Fluidity. Cancer Res 2016; 76:2037-49. [PMID: 26825169 DOI: 10.1158/0008-5472.can-15-1970] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 01/02/2016] [Indexed: 01/03/2023]
Abstract
Despite the high mortality from metastatic cancer, therapeutic targets to prevent metastasis are limited. Efforts to identify genetic aberrations that predispose tumors to metastasis have been mostly unsuccessful. To understand the nature of candidate targets for metastatic disease, we performed an in silico screen to identify drugs that can inhibit a gene expression signature associated with epithelial-mesenchymal transition (EMT). Compounds discovered through this method, including those previously identified, appeared to restrict metastatic capacity through a common mechanism, the ability to modulate the fluidity of cell membranes. Treatment of breast cancer cell lines with the putative antimetastasis agents reduced membrane fluidity, resulting in decreased cell motility, stem cell-like properties, and EMT in vitro, and the drugs also inhibited spontaneous metastasis in vivo When fluidity was unchanged, the antimetastasis compounds could no longer restrict metastasis, indicating a causal association between fluidity and metastasis. We further demonstrate that fluidity can be regulated by cellular cholesterol flux, as the cholesterol efflux channel ABCA1 potentiated metastatic behaviors in vitro and in vivo The requirement for fluidity was further supported by the finding in breast cancer patients that ABCA1 was overexpressed in 41% of metastatic tumors, reducing time to metastasis by 9 years. Collectively, our findings reveal increased membrane fluidity as a necessary cellular feature of metastatic potential that can be controlled by many currently available drugs, offering a viable therapeutic opportunity to prevent cancer metastasis. Cancer Res; 76(7); 2037-49. ©2016 AACR.
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Affiliation(s)
- Weina Zhao
- Department of Integrative Biology & Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas
| | - Sara Prijic
- Department of Integrative Biology & Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas
| | - Bettina C Urban
- Department of Integrative Biology & Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas
| | - Michael J Tisza
- Department of Integrative Biology & Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas
| | - Yan Zuo
- Department of Integrative Biology & Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas
| | - Lin Li
- Department of Integrative Biology & Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas
| | - Zhi Tan
- Department of Integrative Biology & Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas. Graduate School of Biomedical Sciences, Houston, Texas
| | - Xiaoling Chen
- School of Biomedical Informatics, University of Texas Health Science Center at Houston, Houston, Texas
| | - Sendurai A Mani
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Jeffrey T Chang
- Department of Integrative Biology & Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas. Graduate School of Biomedical Sciences, Houston, Texas. School of Biomedical Informatics, University of Texas Health Science Center at Houston, Houston, Texas. Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, Texas. Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas.
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22
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Ditiatkovski M, Neelisetti VNLV, Cui HL, Malesevic M, Fischer G, Bukrinsky M, Sviridov D. Inhibition of extracellular cyclophilins with cyclosporine analog and development of atherosclerosis in apolipoprotein E-deficient mice. J Pharmacol Exp Ther 2015; 353:490-5. [PMID: 25788712 PMCID: PMC11047113 DOI: 10.1124/jpet.115.223420] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 03/17/2015] [Indexed: 11/22/2022] Open
Abstract
Cyclophilins exert both intracellular and extracellular activities related to immune responses and inflammation, which have been implicated in pathogenesis of atherosclerosis. Pan-inhibition of cyclophilins has both pro- and antiatherosclerotic properties, but specific contributions of extracellular and intracellular cyclophilins to these effects have not been characterized. Here, using selective inhibitor of extracellular cyclophilins, we investigated the role of these molecules in atherosclerosis. Apolipoprotein E-null mice fed a high-fat diet received intraperitoneal injections every second day of either vehicle or two analogs of cyclosporine A (CsA): [Melle](4)-CsA (NIM811), a nonimmunosupressive cell-permeable inhibitor of both intracellular and extracellular cyclophilins; and [(4R)-4-[(6-carboxy-1H-benzo[d]imidazol-2-yl)-methyl]-4-methyl-l-threonine](1)-CsA (MM284), cell-impermeable analog only inhibiting extracellular cyclophilins. Development of atherosclerosis and composition of plaques in aorta and innominate artery were studied. Both analogs increased abundance and cross-sectional size of the atherosclerotic plaques in aorta but did not affect development of atherosclerosis in innominate artery. Neither compound affected abundance of macrophages and amount of vascular cell adhesion molecule-1 or nitrotyrosine in the plaques of both arteries. Both compounds reduced the amount of collagen in innominate artery without affecting abundance of collagen in aortic sinus. MM284, but not NIM811, significantly reduced plasma concentration of tumor necrosis factor-α (TNFα); neither compound affected plasma concentrations of interleukin (IL)-6, IL-10 or monocyte chemoattractant protein-1. Ratio between different populations of immune cells in blood or isolated from lymph nodes and spleen as well as plasma lipoprotein profile were unaffected by both compounds. In conclusion, selective inhibition of extracellular cyclophilins reduced TNFα levels in plasma but increased atherosclerosis.
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Affiliation(s)
- Michael Ditiatkovski
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (M.D., V.N.L.V.N., H.L.C., D.S.); Department of Biochemistry, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany (M.M.); Max Planck Institute for Biophysical Chemistry, Gottingen, Germany (G.F.); and Department of Microbiology, and Immunology and Tropical Medicine, George Washington University, Washington, DC (M.B.)
| | - Vijaya N L V Neelisetti
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (M.D., V.N.L.V.N., H.L.C., D.S.); Department of Biochemistry, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany (M.M.); Max Planck Institute for Biophysical Chemistry, Gottingen, Germany (G.F.); and Department of Microbiology, and Immunology and Tropical Medicine, George Washington University, Washington, DC (M.B.)
| | - Huanhuan L Cui
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (M.D., V.N.L.V.N., H.L.C., D.S.); Department of Biochemistry, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany (M.M.); Max Planck Institute for Biophysical Chemistry, Gottingen, Germany (G.F.); and Department of Microbiology, and Immunology and Tropical Medicine, George Washington University, Washington, DC (M.B.)
| | - Miroslav Malesevic
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (M.D., V.N.L.V.N., H.L.C., D.S.); Department of Biochemistry, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany (M.M.); Max Planck Institute for Biophysical Chemistry, Gottingen, Germany (G.F.); and Department of Microbiology, and Immunology and Tropical Medicine, George Washington University, Washington, DC (M.B.)
| | - Gunter Fischer
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (M.D., V.N.L.V.N., H.L.C., D.S.); Department of Biochemistry, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany (M.M.); Max Planck Institute for Biophysical Chemistry, Gottingen, Germany (G.F.); and Department of Microbiology, and Immunology and Tropical Medicine, George Washington University, Washington, DC (M.B.)
| | - Michael Bukrinsky
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (M.D., V.N.L.V.N., H.L.C., D.S.); Department of Biochemistry, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany (M.M.); Max Planck Institute for Biophysical Chemistry, Gottingen, Germany (G.F.); and Department of Microbiology, and Immunology and Tropical Medicine, George Washington University, Washington, DC (M.B.)
| | - Dmitri Sviridov
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (M.D., V.N.L.V.N., H.L.C., D.S.); Department of Biochemistry, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany (M.M.); Max Planck Institute for Biophysical Chemistry, Gottingen, Germany (G.F.); and Department of Microbiology, and Immunology and Tropical Medicine, George Washington University, Washington, DC (M.B.)
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23
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Abstract
ABCA1 mediates the secretion of cellular free cholesterol and phospholipids to an extracellular acceptor, apolipoprotein AI, to form nascent high-density lipoprotein (HDL). Thus, ABCA1 is a key molecule in cholesterol homeostasis. Functional studies of certain Tangier disease mutations demonstrate that ABCA1 has multiple activities, including plasma membrane remodeling and apoAI binding to cell surface, which participate in nascent HDL biogenesis. Recent advances in our understanding of ABCA1 have demonstrated that ABCA1also mediates unfolding the N terminus of apoAI on the cell surface, followed by lipidation of apoAI and release of nascent HDL. Although ABCA1-mediated cholesterol efflux to apoAI can occur on the plasma membrane, the role of apoAI retroendocytosis during cholesterol efflux may play a role in macrophage foam cells that store cholesterol esters in cytoplasmic lipid droplets.
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Affiliation(s)
- Shuhui Wang
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland OH 44195, USA
| | - Jonathan D. Smith
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland OH 44195, USA
- Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland OH 44195, USA
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24
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Omura R, Nagao K, Kobayashi N, Ueda K, Saito H. Direct detection of ABCA1-dependent HDL formation based on lipidation-induced hydrophobicity change in apoA-I. J Lipid Res 2014; 55:2423-31. [PMID: 25214539 DOI: 10.1194/jlr.d049445] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
ABCA1 mediates the efflux of cholesterol and phospholipids into apoA-I to form HDL, which is important in the prevention of atherosclerosis. To develop a novel method for the evaluation of HDL formation, we prepared an apoA-I-POLARIC by labeling the specific residue of an apoA-I variant with a hydrophobicity-sensitive fluorescence probe that detects the environmental change around apoA-I during HDL formation. apoA-I-POLARIC possesses the intact ABCA1-dependent HDL formation activity and shows 4.0-fold higher fluorescence intensity in HDL particles than in the lipid-free state. Incubation of apoA-I-POLARIC with ABCA1-expressing cells, but not ABCA1-non-expressing cells, caused a 1.7-fold increase in fluorescence intensity. Gel filtration analysis demonstrated that the increase in fluorescence intensity of apoA-I-POLARIC represents the amount of apoA-I incorporated into the discoidal HDL particles rather than the amount of secreted cholesterol. THP-1 macrophage-mediated HDL formation and inhibition of HDL formation by cyclosporine A could also be measured using apoA-I-POLARIC. Furthermore, HDL formation-independent lipid release induced by microparticle formation or cell death was not detected by apoA-I-POLARIC. These results demonstrate that HDL formation by ABCA1-expressing cells can be specifically detected by sensing hydrophobicity change in apoA-I, thus providing a novel method for assessing HDL formation and screening of the HDL formation modulator.
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Affiliation(s)
- Risa Omura
- Institute of Health Biosciences and Graduate School of Pharmaceutical Sciences, The University of Tokushima, Tokushima 770-8505, Japan
| | - Kohjiro Nagao
- Institute of Health Biosciences and Graduate School of Pharmaceutical Sciences, The University of Tokushima, Tokushima 770-8505, Japan
| | | | - Kazumitsu Ueda
- Laboratory of Cellular Biochemistry, Division of Applied Life Sciences, Kyoto University Graduate School of Agriculture, Kyoto 606-8502, Japan Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto 606-8502, Japan
| | - Hiroyuki Saito
- Institute of Health Biosciences and Graduate School of Pharmaceutical Sciences, The University of Tokushima, Tokushima 770-8505, Japan
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25
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Hessel S, Gottschalk C, Schumann D, These A, Preiss-Weigert A, Lampen A. Structure-activity relationship in the passage of different pyrrolizidine alkaloids through the gastrointestinal barrier: ABCB1 excretes heliotrine and echimidine. Mol Nutr Food Res 2013; 58:995-1004. [PMID: 24375927 DOI: 10.1002/mnfr.201300707] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 10/30/2013] [Accepted: 10/30/2013] [Indexed: 01/25/2023]
Abstract
SCOPE 1,2-Unsaturated pyrrolizidine alkaloids (PA) are found in plants such as Asteraceae and Boraginaceae families. Acute PA poisoning via contaminated food or feed causes severe damage to liver depending on species-specific oral bioavailability. For assessing PA bioavailability, their passage across the intestinal barrier was investigated using Caco-2 cells. METHODS Differentiated Caco-2 cells were exposed in transport chambers to the PA heliotrine (Hn), echimidine (Em), senecionine (Sc), and senkirkine (Sk). Cell supernatants were analyzed by LC-MS/MS. RESULTS PA pass Caco-2 monolayer from the apical into basolateral compartment depending on their chemical structure. Compared to the cyclic diesters Sc and Sk with a passage rate of 47% ± 4 and 40% ± 3, respectively, the transferred amount of the monoester Hn (32% ± 3) and open-chained diester Em (13% ± 2) was substantially lower. This suggested an active transport of Hn and Em. Using Madin-Darby canine kidney II/P-glycoprotein (ABCB1)-overexpressing cells, the active excretion of Hn and Em by ABCB1 from the gastrointestinal epithelium into the gut lumen was shown. CONCLUSION PA cross the intestinal barrier structure-dependently. The passage of the noncyclic PA Hn and Em is reduced by an ABCB1-driven efflux into the gastrointestinal lumen resulting in a decreased oral bioavailability.
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Affiliation(s)
- Stefanie Hessel
- Federal Institute for Risk Assessment (BfR), Berlin, Germany
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26
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Zanotti I, Greco D, Lusardi G, Zimetti F, Potì F, Arnaboldi L, Corsini A, Bernini F. Cyclosporine A impairs the macrophage reverse cholesterol transport in mice by reducing sterol fecal excretion. PLoS One 2013; 8:e71572. [PMID: 23951193 PMCID: PMC3739729 DOI: 10.1371/journal.pone.0071572] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 07/03/2013] [Indexed: 12/04/2022] Open
Abstract
Despite the efficacy in reducing acute rejection events in organ transplanted subjects, long term therapy with cyclosporine A is associated with increased atherosclerotic cardiovascular morbidity. We studied whether this drug affects the antiatherogenic process of the reverse cholesterol transport from macrophages in vivo. Cyclosporine A 50 mg/kg/d was administered to C57BL/6 mice by subcutaneous injection for 14 days. Macrophage reverse cholesterol transport was assessed by following [3H]-cholesterol mobilization from pre-labeled intraperitoneally injected macrophages, expressing or not apolipoprotein E, to plasma, liver and feces. The pharmacological treatment significantly reduced the amount of radioactive sterols in the feces, independently on the expression of apolipoprotein E in the macrophages injected into recipient mice and in absence of changes of plasma levels of high density lipoprotein-cholesterol. Gene expression analysis revealed that cyclosporine A inhibited the hepatic levels of cholesterol 7-alpha-hydroxylase, concomitantly with the increase in hepatic and intestinal expression of ATP Binding Cassette G5. However, the in vivo relevance of the last observation was challenged by the demonstration that mice treated or not with cyclosporine A showed the same levels of circulating beta-sitosterol. These results indicate that treatment of mice with cyclosporine A impaired the macrophage reverse cholesterol transport by reducing fecal sterol excretion, possibly through the inhibition of cholesterol 7-alpha-hydroxylase expression. The current observation may provide a potential mechanism for the high incidence of atherosclerotic coronary artery disease following the immunosuppressant therapy in organ transplanted recipients.
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Affiliation(s)
- Ilaria Zanotti
- Dipartimento di Farmacia, Università degli Studi di Parma, Parma, Italy.
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27
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Luu W, Sharpe LJ, Gelissen IC, Brown AJ. The role of signalling in cellular cholesterol homeostasis. IUBMB Life 2013; 65:675-84. [PMID: 23847008 DOI: 10.1002/iub.1182] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 04/21/2013] [Indexed: 12/19/2022]
Abstract
Cholesterol is a vital lipid and performs diverse functions on a whole body and cellular level. However, excess cellular cholesterol is toxic, and thus, elegant mechanisms have evolved to tightly regulate this important lipid. The regulation of cholesterol homeostasis is an area of intense research, and the role that signalling plays is gradually becoming more widely recognised. Cholesterol homeostasis is achieved through intricate mechanisms involving synthesis, uptake, and efflux. Although there is a large body of work elucidating these cholesterol-related pathways, less is known about the role of signalling in these processes. Here, we discuss the variety of ways that signalling impacts on these modes and levels of cholesterol homeostasis, including transcriptional regulation. Most work thus far has investigated the role of kinases in cholesterol efflux (especially on ATP-binding cassette transporter A1, ABCA1), and therefore constitutes a major focus of this review. We also indicate further avenues to explore in the area of signalling in cellular cholesterol homeostasis.
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Affiliation(s)
- Winnie Luu
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, NSW, Australia
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28
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Lv YC, Yin K, Fu YC, Zhang DW, Chen WJ, Tang CK. Posttranscriptional Regulation ofATP-Binding Cassette Transporter A1in Lipid Metabolism. DNA Cell Biol 2013; 32:348-58. [DOI: 10.1089/dna.2012.1940] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Affiliation(s)
- Yun-cheng Lv
- Key Laboratory for Atherosclerology of Hunan Province, Institute of Cardiovascular Research, Life Science Research Center, University of South China, Hengyang, China
- Laboratory of Clinical Anatomy, University of South China, Hengyang, China
| | - Kai Yin
- Key Laboratory for Atherosclerology of Hunan Province, Institute of Cardiovascular Research, Life Science Research Center, University of South China, Hengyang, China
| | - Yu-chang Fu
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama
| | - Da-wei Zhang
- Department of Pediatrics and Group on the Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Canada
| | - Wu-jun Chen
- Key Laboratory for Atherosclerology of Hunan Province, Institute of Cardiovascular Research, Life Science Research Center, University of South China, Hengyang, China
| | - Chao-ke Tang
- Key Laboratory for Atherosclerology of Hunan Province, Institute of Cardiovascular Research, Life Science Research Center, University of South China, Hengyang, China
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29
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Nagao K, Maeda M, Mañucat NB, Ueda K. Cyclosporine A and PSC833 inhibit ABCA1 function via direct binding. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1831:398-406. [PMID: 23153588 DOI: 10.1016/j.bbalip.2012.11.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 10/06/2012] [Accepted: 11/05/2012] [Indexed: 10/27/2022]
Abstract
ATP-binding cassette protein A1 (ABCA1) plays a key role in generating high-density lipoprotein (HDL). However, the detailed mechanism of HDL formation remains unclear; in order to reveal it, chemicals that specifically block each step of HDL formation would be useful. Cyclosporine A inhibits ABCA1-mediated cholesterol efflux, but it is not clear whether this is mediated via inhibition of calcineurin. We analyzed the effects of cyclosporine A and related compounds on ABCA1 function in BHK/ABCA1 cells. Cyclosporine A, FK506, and pimecrolimus inhibited ABCA1-mediated cholesterol efflux in a concentration-dependent manner, with IC(50) of 7.6, 13.6, and 7.0μM, respectively. An mTOR inhibitor, rapamycin also inhibited ABCA1, with IC(50) of 18.8μM. The primary targets for these drugs were inhibited at much lower concentrations in BHK/ABCA1 cells, suggesting that they were not involved. Binding of [(3)H] cyclosporine A to purified ABCA1 could be clearly detected. Furthermore, a non-immunosuppressive cyclosporine, PSC833, inhibited ABCA1-mediated cholesterol efflux with IC(50) of 1.9μM, and efficiently competed with [(3)H] cyclosporine A binding to ABCA1. These results indicate that cyclosporine A and PSC833 inhibit ABCA1 via direct binding, and that the ABCA1 inhibitor PSC833 is an excellent candidate for further investigations of the detailed mechanisms underlying formation of HDL.
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Affiliation(s)
- Kohjiro Nagao
- Institute for integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto 606-8502, Japan
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30
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Reboulleau A, Robert V, Vedie B, Doublet A, Grynberg A, Paul JL, Fournier N. Involvement of cholesterol efflux pathway in the control of cardiomyocytes cholesterol homeostasis. J Mol Cell Cardiol 2012; 53:196-205. [PMID: 22668787 DOI: 10.1016/j.yjmcc.2012.05.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 05/10/2012] [Accepted: 05/26/2012] [Indexed: 11/16/2022]
Abstract
Although cholesterol-rich microdomains are highly involved in the functions of cardiomyocytes, the cholesterol homeostasis is largely unknown in these cells. We developed experimental procedures to assess cholesterol synthesis, cholesterol masses and cholesterol efflux from primary cultures of cardiac myocytes obtained from 2 to 4 days old Wistar rats. We first observed that cardiomyocytes poorly internalized exogenously supplied native or modified LDL and that free cholesterol (FC) efflux to free apolipoprotein AI (apo AI) and to HDL was mediated by ATP binding cassette transporter A1 (ABCA1) and likely by ATP binding cassette transporter G1 (ABCG1), respectively, which are both upregulated by liver X receptor/retinoid X receptor (LXR/RXR) activation. We then investigated the consequences of cholesterol synthesis inhibition on cholesterol homeostasis using an HMGCoA reductase inhibitor (pravastatin, 90% effective concentration (EC90): 0.11 mM, 18 h). We observed no impact of cholesterol synthesis inhibition on the FC or cholesteryl ester (CE) masses. Consistently with no FC mass changes, pravastatin treatment had no notable impact on LDL receptors mRNA expression or on the capacity of cardiomyocytes to uptake radiolabeled LDL. Conversely, pravastatin treatment induced a significant decrease of cholesterol efflux to both apo AI and HDL whereas the passive aqueous diffusion remained unchanged. The cholesterol efflux pathway reductions induced by cholesterol synthesis inhibition were not caused by a reduction of ABC transporter expression (mRNA or protein). These results show that cardiac myocytes down-regulate active cholesterol efflux processes when endogenous cholesterol synthesis is inhibited, allowing them to preserve cholesterol homeostasis.
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Affiliation(s)
- Anne Reboulleau
- Univ Paris-Sud, EA 4529, UFR de Pharmacie, 92296 Châtenay-Malabry, France
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31
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Zhao GJ, Yin K, Fu YC, Tang CK. The interaction of ApoA-I and ABCA1 triggers signal transduction pathways to mediate efflux of cellular lipids. Mol Med 2012; 18:149-58. [PMID: 22064972 DOI: 10.2119/molmed.2011.00183] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 11/01/2011] [Indexed: 12/17/2022] Open
Abstract
Reverse cholesterol transport (RCT) has been characterized as a crucial step for antiatherosclerosis, which is initiated by ATP-binding cassette A1 (ABCA1) to mediate the efflux of cellular phospholipids and cholesterol to lipid-free apolipoprotein A-I (apoA-I). However, the mechanisms underlying apoA-I/ABCA1 interaction to lead to the lipidation of apoA-I are poorly understood. There are several models proposed for the interaction of apoA-I with ABCA1 as well as the lipidation of apoA-I mediated by ABCA1. ApoA-I increases the levels of ABCA1 protein markedly. In turn, ABCA1 can stabilize apoA-I. The interaction of apoA-I with ABCA1 could activate signaling molecules that modulate posttranslational ABCA1 activity or lipid transport activity. The key signaling molecules in these processes include protein kinase A (PKA), protein kinase C (PKC), Janus kinase 2 (JAK2), Rho GTPases and Ca²⁺, and many factors also could influence the interaction of apoA-I with ABCA1. This review will summarize these mechanisms for the apoA-I interaction with ABCA1 as well as the signal transduction pathways involved in these processes.
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Affiliation(s)
- Guo-Jun Zhao
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang, China
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32
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Ponnudurai RP, Basak T, Ahmad S, Bhardwaj G, Chauhan RK, Singh RA, Lalwani MK, Sivasubbu S, Sengupta S. Proteomic analysis of zebrafish (Danio rerio) embryos exposed to cyclosporine A. J Proteomics 2012; 75:1004-17. [DOI: 10.1016/j.jprot.2011.10.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2011] [Revised: 09/28/2011] [Accepted: 10/21/2011] [Indexed: 10/15/2022]
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33
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Chen CY, Shyue SK, Ching LC, Su KH, Wu YL, Kou YR, Chiang AN, Pan CC, Lee TS. Wogonin promotes cholesterol efflux by increasing protein phosphatase 2B-dependent dephosphorylation at ATP-binding cassette transporter-A1 in macrophages. J Nutr Biochem 2011; 22:1015-21. [DOI: 10.1016/j.jnutbio.2010.08.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 08/16/2010] [Accepted: 08/31/2010] [Indexed: 11/26/2022]
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34
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Fournier N, Attia N, Rousseau-Ralliard D, Vedie B, Destaillats F, Grynberg A, Paul JL. Deleterious impact of elaidic fatty acid on ABCA1-mediated cholesterol efflux from mouse and human macrophages. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1821:303-12. [PMID: 22074701 DOI: 10.1016/j.bbalip.2011.10.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 09/07/2011] [Accepted: 10/05/2011] [Indexed: 10/16/2022]
Abstract
Consumption of trans fatty acids (TFA) increase cardiovascular risk more than do saturated FA, but the mechanisms explaining their atherogenicity are still unclear. We investigated the impact of membrane incorporation of TFA on cholesterol efflux by exposing J774 mouse macrophages or human monocyte-derived macrophages (HMDM) to media enriched or not (standard medium) with industrially produced elaidic (trans-9 18:1) acid, naturally produced vaccenic (trans-11 18:1) acid (34 h, 70 μM) or palmitic acid. In J774 macrophages, elaidic and palmitic acid, but not vaccenic acid, reduced ABCA1-mediated efflux by ~23% without affecting aqueous diffusion, SR-BI or ABCG1-mediated pathways, and this effect was maintained in cholesterol-loaded cells. The impact of elaidic acid on the ABCA1 pathway was weaker in cholesterol-normal HMDM, but elaidic acid induced a strong reduction of ABCA1-mediated efflux in cholesterol-loaded cells (-36%). In J774 cells, the FA supplies had no impact on cellular free cholesterol or cholesteryl ester masses, the abundance of ABCA1 mRNA or the total and plasma membrane ABCA1 protein content. Conversely, TFA or palmitic acid incorporation induced strong modifications of the membrane FA composition with a decrease in the ratio of (cis-monounsaturated FA+polyunsaturated FA):(saturated FA+TFA), with elaidic and vaccenic acids representing each 20% and 13% of the total FA composition, respectively. Moreover, we demonstrated that cellular ATP was required for the effect of elaidic acid, suggesting that it contributes to atherogenesis by impairing ABCA1-mediated cholesterol efflux in macrophages, likely by decreasing the membrane fluidity, which could thereby reduce ATPase activity and the function of the transporter.
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Affiliation(s)
- Natalie Fournier
- Univ Paris-Sud, EA 4529, UFR de Pharmacie, 92296 Châtenay-Malabry, France.
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35
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Morel O, Morel N, Jesel L, Freyssinet JM, Toti F. Microparticles: a critical component in the nexus between inflammation, immunity, and thrombosis. Semin Immunopathol 2011; 33:469-86. [DOI: 10.1007/s00281-010-0239-3] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2010] [Accepted: 12/20/2010] [Indexed: 12/27/2022]
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36
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Lee JY, Karwatsky J, Ma L, Zha X. ABCA1 increases extracellular ATP to mediate cholesterol efflux to ApoA-I. Am J Physiol Cell Physiol 2011; 301:C886-94. [PMID: 21697542 DOI: 10.1152/ajpcell.00042.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
ATP-binding cassette protein A1 (ABCA1) is a key plasma membrane protein required for the efflux of cellular cholesterol to extracellular acceptors, particularly to apolipoprotein A-I (apoA-I). This process is essential to maintain cholesterol homeostasis in the body. The detailed molecular mechanisms, however, are still insufficiently understood. Also, the molecular identity of ABCA1, i.e., channel, pump, or flippase, remains unknown. In this study we analyzed extracellular ATP levels in the medium of ABCA1-expressing BHK cells and RAW macrophages and compared them to the medium of nonexpressing cells. We found that extracellular ATP concentrations are significantly elevated when cells express ABCA1. Importantly, a dysfunctional ABCA1 mutant (A937V), when expressed similarly as wild-type ABCA1, is unable to raise extracellular ATP concentration, which suggests a casual relationship between functional ABCA1 and elevated extracellular ATP. To explore the physiological role of extracellular ATP, we analyzed ABCA1-mediated cholesterol efflux under conditions where extracellular ATP levels were modulated. We found that increasing extracellular ATP within the physiological range, i.e., <μM, promotes cholesterol efflux to apoA-I. On the other hand, removing extracellular ATP, either by adding apyrase to the medium or by expressing a plasma membrane-bound ectonucleotidase, CD39, abolishes cholesterol efflux to apoA-I. On the basis of these results, we conclude that, through direct or indirect mechanisms, ABCA1 functions to raise ATP levels in the medium. This elevated extracellular ATP is required for ABCA1-mediated cholesterol efflux to apoA-I.
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Nagao K, Tomioka M, Ueda K. Function and regulation of ABCA1 - membrane meso-domain organization and reorganization. FEBS J 2011; 278:3190-203. [DOI: 10.1111/j.1742-4658.2011.08170.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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38
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Ohnsorg PM, Rohrer L, Perisa D, Kateifides A, Chroni A, Kardassis D, Zannis VI, von Eckardstein A. Carboxyl terminus of apolipoprotein A-I (ApoA-I) is necessary for the transport of lipid-free ApoA-I but not prelipidated ApoA-I particles through aortic endothelial cells. J Biol Chem 2011; 286:7744-7754. [PMID: 21209084 DOI: 10.1074/jbc.m110.193524] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
High density lipoproteins (HDL) and apolipoprotein A-I (apoA-I) must leave the circulation and pass the endothelium to exert their atheroprotective actions in the arterial wall. We previously demonstrated that the transendothelial transport of apoA-I involves ATP-binding cassette transporter (ABC) A1 and re-secretion of lipidated particles. Transendothelial transport of HDL is modulated by ABCG1 and the scavenger receptor BI (SR-BI). We hypothesize that apoA-I transport is started by the ABCA1-mediated generation of a lipidated particle which is then transported by ABCA1-independent pathways. To test this hypothesis we analyzed the endothelial binding and transport properties of initially lipid-free as well as prelipidated apoA-I mutants. Lipid-free apoA-I mutants with a defective carboxyl-terminal domain showed an 80% decreased specific binding and 90% decreased specific transport by aortic endothelial cells. After prior cell-free lipidation of the mutants, the resulting HDL-like particles were transported through endothelial cells by an ABCG1- and SR-BI-dependent process. ApoA-I mutants with deletions of either the amino terminus or both the amino and carboxyl termini showed dramatic increases in nonspecific binding but no specific binding or transport. Prior cell-free lipidation did not rescue these anomalies. Our findings of stringent structure-function relationships underline the specificity of transendothelial apoA-I transport and suggest that lipidation of initially lipid-free apoA-I is necessary but not sufficient for specific transendothelial transport. Our data also support the model of a two-step process for the transendothelial transport of apoA-I in which apoA-I is initially lipidated by ABCA1 and then further processed by ABCA1-independent mechanisms.
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Affiliation(s)
- Pascale M Ohnsorg
- From the Institute of Clinical Chemistry, University Hospital of Zurich, 8091 Zurich, Switzerland,; the Competence Center for Systems Physiology and Metabolic Diseases, ETH and University of Zurich, 8091 Zurich, Switzerland
| | - Lucia Rohrer
- From the Institute of Clinical Chemistry, University Hospital of Zurich, 8091 Zurich, Switzerland,; the Center for Integrative Human Physiology, University of Zurich, 8091 Zurich, Switzerland
| | - Damir Perisa
- From the Institute of Clinical Chemistry, University Hospital of Zurich, 8091 Zurich, Switzerland,; the Center for Integrative Human Physiology, University of Zurich, 8091 Zurich, Switzerland
| | - Andreas Kateifides
- Molecular Genetics, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts 02118,; the Department of Biochemistry, Division of Basic Sciences, Institute of Molecular Biology and Biotechnology, University of Crete Medical School, 71201 Crete, Greece
| | - Angeliki Chroni
- the National Centre of Scientific Research "Demokritos," Institute of Biology, 15310 Athens, Greece, and
| | - Dimitris Kardassis
- the Department of Biochemistry, Division of Basic Sciences, Institute of Molecular Biology and Biotechnology, University of Crete Medical School, 71201 Crete, Greece
| | - Vassilis I Zannis
- Molecular Genetics, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts 02118,; the Department of Biochemistry, Division of Basic Sciences, Institute of Molecular Biology and Biotechnology, University of Crete Medical School, 71201 Crete, Greece
| | - Arnold von Eckardstein
- From the Institute of Clinical Chemistry, University Hospital of Zurich, 8091 Zurich, Switzerland,; the Competence Center for Systems Physiology and Metabolic Diseases, ETH and University of Zurich, 8091 Zurich, Switzerland,; the Center for Integrative Human Physiology, University of Zurich, 8091 Zurich, Switzerland,.
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Van Summeren A, Renes J, Bouwman FG, Noben JP, van Delft JHM, Kleinjans JCS, Mariman ECM. Proteomics Investigations of Drug-Induced Hepatotoxicity in HepG2 Cells. Toxicol Sci 2010; 120:109-22. [DOI: 10.1093/toxsci/kfq380] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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The β-subunit of ATP synthase is involved in cellular uptake and resecretion of apoA-I but does not control apoA-I-induced lipid efflux in adipocytes. Mol Cell Biochem 2010; 348:155-64. [PMID: 21069432 DOI: 10.1007/s11010-010-0650-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Accepted: 10/28/2010] [Indexed: 10/18/2022]
Abstract
Cellular uptake and resecretion of apoA-I (apoA-I recycling) could be an important factor in determining the circulating plasma levels of apoA-I and/or HDL. Using a novel method to study protein recycling, we have recently demonstrated recycling of apoA-I by adipocytes and suggested that this is a receptor mediated process independent of ABCA1 function. In the present study, it is shown that apoA-I recycling by adipocytes can be blocked by a monoclonal antibody against the β-subunit of ATP synthase, a protein that had been previously identified as an apoA-I receptor. Investigation of the cellular recycling of two other proteins, an apolipoprotein and a small globular protein, showed that recycling of apoA-I is a selective process. The present study also shows that blocking apoA-I recycling has no effect on the rate of apoA-I-induced cholesterol or phospholipid efflux. It is concluded that cellular recycling of apoA-I is a selective process that involves the ectopically expressed β-subunit of ATP synthase. The physiological function of apoA-I recycling remains to be elucidated. However, this study shows that the process of apoA-I uptake and resecretion is not required for apoA-I lipidation.
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Kockx M, Jessup W, Kritharides L. Cyclosporin A and atherosclerosis--cellular pathways in atherogenesis. Pharmacol Ther 2010; 128:106-18. [PMID: 20598751 DOI: 10.1016/j.pharmthera.2010.06.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Accepted: 06/02/2010] [Indexed: 12/31/2022]
Abstract
Cyclosporin A (CsA) is an immunosuppressant drug widely used in organ transplant recipients and people with autoimmune disorders. Long term treatment with CsA is associated with many side effects including hyperlipidemia and an increased risk of atherosclerosis. While its immunosuppressive effects are closely linked to its effects on T cell activation via the inhibition of the nuclear factor of activated T cells (NFAT) pathway, the precise mechanisms underlying its cardiovascular effects appear to involve multiple pathways additional to those relevant for immunosuppression. These include inhibition of calcineurin activity and intracellular cyclophilin peptidylprolyl isomerase and chaperone activities, inhibition of pro-inflammatory extracellular cyclophilin A, and NFAT-independent transcriptional effects. CsA demonstrates complex effects on lipoprotein metabolism and bile acid production, and affects endothelial cells, smooth muscle cells and macrophages, all of which are critical to the atherosclerotic process. Interpretation of the available data is hampered as many experimental models are used to study the effects of CsA in vivo and in vitro, leading to diverse and often contradictory findings. In this review we will describe the cellular mechanisms related to CsA-induced hyperlipidemia and atherosclerosis, with a focus on identifying pro-atherogenic pathways that are distinct from those relevant to its immunosuppressant effects. The potential of CsA analogues to avoid such sequelae will be discussed.
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Affiliation(s)
- Maaike Kockx
- Macrophage Biology Group, Centre for Vascular Research, University of New South Wales, Sydney, Australia
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42
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Model system for the analysis of cell surface expression of human ABCA1. BMC Cell Biol 2009; 10:93. [PMID: 20025763 PMCID: PMC2804593 DOI: 10.1186/1471-2121-10-93] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Accepted: 12/21/2009] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND The ABCA1 protein plays a pivotal role in reverse cholesterol transport, by mediating the generation of HDL particles and removing cellular cholesterol. Both the proper expression of ABCA1 in the plasma membrane and the internalization along with apoA-I are required for function. Therefore, we developed a model system to investigate the effect of clinically relevant drugs on the cell surface appearance of ABCA1. RESULTS By retroviral transduction system, we established stable mammalian cell lines expressing functional and non-functional ABCA1 variants, tagged with an extracellular hemagglutinin epitope. After characterization of the expression, proper localization and function of different ABCA1 variants, we followed quantitatively their cell surface expression by immunofluorescent staining, using flow cytometry. As expected, we found increased cell surface expression of ABCA1 after treatment with a calpain inhibitor, and observed a strong decrease in plasma membrane ABCA1 expression upon treatment with a trans-Golgi transport inhibitor, Brefeldin A. We tested cholesterol level lowering drugs and other potential inhibitors of ABCA1. Here we demonstrate that ezetimibe affects ABCA1 cell surface expression only in the case of a functional ABCA1. CONCLUSIONS Our model system allows a quantitative detection of cell surface expression of ABCA1, screening of substrates or specific inhibitors, and investigating transport regulation.
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Karwatsky J, Ma L, Dong F, Zha X. Cholesterol efflux to apoA-I in ABCA1-expressing cells is regulated by Ca2+-dependent calcineurin signaling. J Lipid Res 2009; 51:1144-56. [PMID: 19965585 DOI: 10.1194/jlr.m003145] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ATP-binding cassette transporter A1 (ABCA1) is required for the lipidation of apolipoprotein A-I (apoA-I), although molecular mechanisms supporting this process remain poorly defined. In this study, we focused on the role of cytosolic Ca(2+) and its signaling and found that cytosolic Ca(2+) was required for cholesterol efflux to apoA-I. Removing extracellular Ca(2+) or chelating cytosolic Ca(2+) were equally inhibitory for apoA-I lipidation. We provide evidence that apoA-I induced Ca(2+) influx from the medium. We further demonstrate that calcineurin activity, the downstream target of Ca(2+) influx, was essential; inhibition of calcineurin activity by cyclosporine A or FK506 completely abolished apoA-I lipidation. Furthermore, calcineurin inhibition abolished apoA-I binding and diminished JAK2 phosphorylation, an established signaling event for cholesterol efflux to apoA-I. Finally, we demonstrate that neither Ca(2+) manipulation nor calcineurin inhibition influenced ABCA1's capacity to release microparticles or to remodel the plasma membrane. We conclude that this Ca(2+)-dependent calcineurin/JAK2 pathway is specifically responsible for apoA-I lipidation without directly modifying ABCA1 activity.
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Affiliation(s)
- Joel Karwatsky
- Ottawa Hospital Research Institute and Department of Biochemistry Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8L6, Canada
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Kockx M, Guo DL, Traini M, Gaus K, Kay J, Wimmer-Kleikamp S, Rentero C, Burnett JR, Le Goff W, Van Eck M, Stow JL, Jessup W, Kritharides L. Cyclosporin A decreases apolipoprotein E secretion from human macrophages via a protein phosphatase 2B-dependent and ATP-binding cassette transporter A1 (ABCA1)-independent pathway. J Biol Chem 2009; 284:24144-54. [PMID: 19589783 DOI: 10.1074/jbc.m109.032615] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cyclosporin A (CsA) is an immunosuppressant that inhibits protein phosphatase 2B (PP2B/calcineurin) and is associated with hyperlipidemia, decreased cholesterol efflux via ATP-binding cassette transporter A1 (ABCA1), and increased risk of atherosclerosis. Apolipoprotein E (apoE) is an important regulator of lipid metabolism and atherosclerosis, the secretion of which from human macrophages is regulated by the serine/threonine protein kinase A (PKA) and intracellular calcium (Ca(2+)) (Kockx, M., Guo, D. L., Huby, T., Lesnik, P., Kay, J., Sabaretnam, T., Jary, E., Hill, M., Gaus, K., Chapman, J., Stow, J. L., Jessup, W., and Kritharides, L. (2007) Circ. Res. 101, 607-616). As PP2B is Ca(2+)-dependent and has been linked to PKA-dependent processes, we investigated whether CsA modulated apoE secretion. CsA dose- and time-dependently inhibited secretion of apoE from primary human macrophages and from Chinese hamster ovary cells stably transfected with human apoE and increased cellular apoE levels without affecting apoE mRNA. [(35)S]Met kinetic modeling studies showed that CsA inhibited both secretion and degradation of apoE, increasing the half-life of cellular apoE 2-fold. CsA also inhibited secretion from primary human Tangier disease macrophages and from mouse macrophages deficient in ABCA1, indicating that the effect is independent of the known inhibition of ABCA1 by CsA. The role of PP2B in mediating apoE secretion was confirmed using additional peptide and chemical inhibitors of PP2B. Importantly, kinetic modeling, live-cell imaging, and confocal microscopy all indicated that CsA inhibited apoE secretion by mechanisms quite distinct from those of PKA inhibition, most likely inducing accumulation of apoE in the endoplasmic reticulum compartment. Taken together, these results establish a novel mechanism for the pro-atherosclerotic effects of CsA, and establish for the first time a role for PP2B in regulating the intracellular transport and secretion of apoE.
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Affiliation(s)
- Maaike Kockx
- Centre for Vascular Research, School of Medical Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
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45
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Wang J, Zhang ZR, Chou CF, Liang YY, Gu Y, Ma HP. Cyclosporine stimulates the renal epithelial sodium channel by elevating cholesterol. Am J Physiol Renal Physiol 2008; 296:F284-90. [PMID: 19091785 DOI: 10.1152/ajprenal.90647.2008] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cyclosporine A (CsA) is an efficient immunosuppressant used for reducing allograft rejection but with a severe side effect of causing hypertension. We hypothesize that the renal epithelial sodium channel (ENaC) may participate in CsA-induced hypertension. In the present study, we used the patch-clamp cell-attached configuration to examine whether and how CsA stimulates ENaC in A6 distal nephron cells. The data showed that CsA significantly increased ENaC open probability. Since CsA is an inhibitor of the ATP-binding cassette A1 (ABCA1) transporter, we employed 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), another ABCA1 inhibitor, and found that DIDS mimicked the effects of CsA on ENaC basal and cholesterol-induced activity but without any additive effect if combined with CsA. CsA and DIDS also had an identical effect on reduced ENaC activity caused by cholesterol extraction. ABCA1 protein was detected in A6 cells by Western blot analysis. Confocal microscopy data showed that both CsA and DIDS facilitated A6 cells to uptake cholesterol. Since enhanced ENaC activity is known to cause hypertension, these data together suggest that CsA may cause hypertension by stimulating ENaC through a pathway associated with inhibition of ABCA1 and consequent elevation of cholesterol in the cells.
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Affiliation(s)
- Jing Wang
- Division of Nephrology, Univ. of Alabama at Birmingham, 1530 Third Ave. South, Zeigler Research Bldg. 510, Birmingham, AL 35294, USA
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46
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Affiliation(s)
- John F Oram
- Department of Medicine, University of Washington, Seattle, WA, USA.
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47
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Faulkner LE, Panagotopulos SE, Johnson JD, Woollett LA, Hui DY, Witting SR, Maiorano JN, Davidson WS. An analysis of the role of a retroendocytosis pathway in ABCA1-mediated cholesterol efflux from macrophages. J Lipid Res 2008; 49:1322-32. [PMID: 18359958 DOI: 10.1194/jlr.m800048-jlr200] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ATP binding cassette transporter A-1 (ABCA1) is critical for apolipoprotein-mediated cholesterol efflux, an important mechanism employed by macrophages to avoid becoming lipid-laden foam cells, the hallmark of early atherosclerotic lesions. It has been proposed that lipid-free apolipoprotein A-I (apoA-I) enters the cell and is resecreted as a lipidated particle via a retroendocytosis pathway during ABCA1-mediated cholesterol efflux from macrophages. To determine the functional importance of such a pathway, confocal microscopy was used to characterize the internalization of a fully functional apoA-I cysteine mutant containing a thiol-reactive fluorescent probe in cultured macrophages. ApoA-I was also endogenously labeled with (35)S-methionine to quantify cellular uptake and to determine the metabolic fate of the internalized protein. It was found that apoA-I was specifically taken inside macrophages and that a small amount of intact apoA-I was resecreted from the cells. However, a majority of the label that reappeared in the media was degraded. We estimate that the mass of apoA-I retroendocytosed is not sufficient to account for the HDL produced by the cholesterol efflux reaction. Furthermore, we have demonstrated that lipid-free apoA-I-mediated cholesterol efflux from macrophages can be pharmacologically uncoupled from apoA-I internalization into cells. On the basis these findings, we present a model in which the ABCA1-mediated lipid transfer process occurs primarily at the membrane surface in macrophages, but still accounts for the observed specific internalization of apoA-I.
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Affiliation(s)
- Loren E Faulkner
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati OH, 45237, USA
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48
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Tall AR. Cholesterol efflux pathways and other potential mechanisms involved in the athero-protective effect of high density lipoproteins. J Intern Med 2008; 263:256-73. [PMID: 18271871 DOI: 10.1111/j.1365-2796.2007.01898.x] [Citation(s) in RCA: 308] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Plasma high density lipoprotein (HDL) levels bear a strong independent inverse relationship with atherosclerotic cardiovascular disease. Although HDL has anti-oxidant, anti-inflammatory, vasodilating and anti-thrombotic properties, the central anti-atherogenic activity of HDL is likely to be its ability to remove cholesterol and oxysterols from macrophage foam cells, smooth muscle cells and endothelial cells in the arterial wall. To some extent, the pleotropic athero-protective properties of HDL may be related to its ability to promote sterol and oxysterol efflux from arterial wall cells, as well as to detoxify oxidized phospholipids. In cholesterol-loaded macrophages, activation of liver X receptors (LXRs) leads to increased expression of adenosine triphosphate (ATP) binding cassetter transporter (ABCA1), ATP binding cassetter transporter gene (ABCG1) and apoE and promotes cholesterol efflux. ABCA1 stimulates cholesterol efflux to lipid-poor apolipoproteins, whilst ABCG1 promotes efflux of cholesterol and oxysterols to HDL. Despite some recent setbacks in the clinical arena, there is still intense interest in therapeutically targeting HDL and macrophage cholesterol efflux pathways, via treatments with niacin, cholesterol ester transfer protein inhibitors, LXR activators and infusions of apoA-1, phospholipids and peptides.
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Affiliation(s)
- A R Tall
- Division of Molecular Medicine, Department of Medicine, Columbia University, NY, USA
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49
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Hassan HH, Bailey D, Lee DYD, Iatan I, Hafiane A, Ruel I, Krimbou L, Genest J. Quantitative analysis of ABCA1-dependent compartmentalization and trafficking of apolipoprotein A-I: implications for determining cellular kinetics of nascent high density lipoprotein biogenesis. J Biol Chem 2008; 283:11164-75. [PMID: 18218626 DOI: 10.1074/jbc.m707720200] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The molecular mechanisms underlying the apoA-I/ABCA1 endocytic trafficking pathway in relation to high density lipoprotein (HDL) formation remain poorly understood. We have developed a quantitative cell surface biotinylation assay to determine the compartmentalization and trafficking of apoA-I between the plasma membrane (PM) and intracellular compartments (ICCs). Here we report that (125)I-apoA-I exhibited saturable association with the PM and ICCs in baby hamster kidney cells stably overexpressing ABCA1 and in fibroblasts. The PM was found to have a 2-fold higher capacity to accommodate apoA-I as compared with ICCs. Overexpressing various levels of ABCA1 in baby hamster kidney cells promoted the association of apoA-I with PM and ICCs compartments. The C-terminal deletion of apoA-I Delta(187-243) and reconstituted HDL particles exhibited reduced association of apoA-I with both the PM and ICCs. Interestingly, cell surface biotinylation with a cleavable biotin revealed that apoA-I induces ABCA1 endocytosis. Such endocytosis was impaired by naturally occurring mutations of ABCA1 (Q597R and C1477R). To better understand the role of the endocytotic pathway in the dynamics of the lipidation of apoA-I, a pulse-chase experiment was performed, and the dissociation (re-secretion) of (125)I-apoA-I from both PM and ICCs was monitored over a 6-h period. Unexpectedly, we found that the time required for 50% dissociation of (125)I-apoA-I from the PM was 4-fold slower than that from ICCs at 37 degrees C. Finally, treatment of the cells with phosphatidylcholine-specific phospholipase C, increased the dissociation of apoA-I from the PM. This study provides evidence that the lipidation of apoA-I occurs in two kinetically distinguishable compartments. The finding that apoA-I specifically mediates the continuous endocytic recycling of ABCA1, together with the kinetic data showing that apoA-I associated with ICCs is rapidly re-secreted, suggests that the endocytotic pathway plays a central role in the genesis of nascent HDL.
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Affiliation(s)
- Houssein Hajj Hassan
- Cardiovascular Genetics Laboratory, Division of Cardiology, McGill University Health Centre/Royal Victoria Hospital, Montréal, Québec H3A 1A1, Canada
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Azuma Y, Takada M, Shin HW, Kioka N, Nakayama K, Ueda K. Retroendocytosis pathway of ABCA1/apoA-I contributes to HDL formation. Genes Cells 2008; 14:191-204. [PMID: 19170766 DOI: 10.1111/j.1365-2443.2008.01261.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
ATP-binding cassette protein A1 (ABCA1) mediates transfer of cellular free cholesterol and phospholipids to apolipoprotein A-I (apoA-I), an extracellular acceptor in plasma, to form high-density lipoprotein (HDL). It is currently unknown to what extent ABCA1 endocytosis and recycling contribute to the HDL formation. To address this issue, we expressed human ABCA1 constructs with either an extracellular HA tag or an intracellular GFP tag in cells, and used this system to characterize endocytosis and recycling of ABCA1 and apoA-I. Under basal conditions, ABCA1 and apoA-I are endocytosed via a clathrin- and Rab5-mediated pathway and recycled rapidly back to the cell surface, at least in part via a Rab4-mediated route; approximately 30% of the endocytosed ABCA1 is recycled back to the cell surface. When receptor-mediated endocytosis is inhibited, the level of ABCA1 at the cell surface increases and apoA-I internalization is blocked. Under these conditions, apoA-I mediated cholesterol efflux from cells that have accumulated lipoprotein-derived cholesterol is decreased, whereas efflux from cells without excess cholesterol is increased. These results suggest that the retroendocytosis pathway of ABCA1/apoA-I contributes to HDL formation when excess lipoprotein-derived cholesterol has accumulated in cells.
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