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Nicolson GL, de Mattos GF, Settineri R, Costa C, Ellithorpe R, Rosenblatt S, La Valle J, Jimenez A, Ohta S. Clinical Effects of Hydrogen Administration: From Animal and Human Diseases to Exercise Medicine. ACTA ACUST UNITED AC 2016. [DOI: 10.4236/ijcm.2016.71005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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202
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Pownall HJ, Gotto AM. New Insights into the High-Density Lipoprotein Dilemma. Trends Endocrinol Metab 2016; 27:44-53. [PMID: 26673122 PMCID: PMC4707953 DOI: 10.1016/j.tem.2015.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 11/07/2015] [Accepted: 11/09/2015] [Indexed: 12/21/2022]
Abstract
Although high-density lipoprotein-cholesterol (HDL-C) concentration is a negative risk factor for atherosclerotic cardiovascular disease (CVD), efforts to reduce CVD risk by raising HDL-C have not been uniformly successful. Many studies have shown that alcohol consumption, that increases plasma HDL-C concentration, reduces CVD incidence. However, recent genetic studies in large populations have not only removed HDL-C from the causal link between plasma HDL-C concentration and reduced CVD risk, but also suggest that the association is weak. We propose here that the cardioprotective effects of alcohol are mediated by the interaction of its terminal metabolite, acetate, with the adipocyte free fatty acid receptor 2 (FFAR2), which elicits a profound antilipolytic effect that may increase insulin sensitivity without necessarily raising plasma HDL-C concentration.
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Affiliation(s)
- Henry J. Pownall
- Houston Methodist Research Institute and Weill Cornell Medical College, 6670 Bertner Avenue, Houston TX 77030
| | - Antonio M. Gotto
- Houston Methodist Research Institute and Weill Cornell Medical College, 1305 York Avenue, New York, NY, USA
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203
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Cholesterol Transporters ABCA1 and ABCG1 Gene Expression in Peripheral Blood Mononuclear Cells in Patients with Metabolic Syndrome. CHOLESTEROL 2015; 2015:682904. [PMID: 26788366 PMCID: PMC4692991 DOI: 10.1155/2015/682904] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 10/24/2015] [Accepted: 11/17/2015] [Indexed: 01/09/2023]
Abstract
ABCA1 and ABCG1 genes encode the cholesterol transporter proteins that play a key role in cholesterol and phospholipids homeostasis. This study was aimed at evaluating and comparing ABCA1 and ABCG1 genes expression in metabolic syndrome patients and healthy individuals. This case-control study was performed on 36 patients with metabolic syndrome and the same number of healthy individuals in Hamadan (west of Iran) during 2013-2014. Total RNA was extracted from mononuclear cells and purified using RNeasy Mini Kit column. The expression of ABCA1 and ABCG1 genes was performed by qRT-PCR. Lipid profile and fasting blood glucose were measured using colorimetric procedures. ABCG1 expression in metabolic syndrome patients was significantly lower (about 75%) compared to that of control group, while for ABCA1 expression, there was no significant difference between the two studied groups. Comparison of other parameters such as HDL-C, FBS, BMI, waist circumference, and systolic and diastolic blood pressure between metabolic syndrome patients and healthy individuals showed significant differences (P < 0.05). Decrease in ABCG1 expression in metabolic syndrome patients compared to healthy individuals suggests that hyperglycemia, related metabolites, and hyperlipidemia over the transporter capacity resulted in decreased expression of ABCG1. Absence of a significant change in ABCA1 gene expression between two groups can indicate a different regulation mechanism for ABCA1 expression.
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204
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Subfraction analysis of circulating lipoproteins in a patient with Tangier disease due to a novel ABCA1 mutation. Clin Chim Acta 2015; 452:167-72. [PMID: 26616730 DOI: 10.1016/j.cca.2015.11.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 11/22/2015] [Indexed: 12/30/2022]
Abstract
Tangier disease, characterized by low or absent high-density lipoprotein (HDL), is a rare hereditary lipid storage disorder associated with frequent, but not obligatory, severe premature atherosclerosis due to disturbed reverse cholesterol transport from tissues. The reasons for the heterogeneity in atherogenicity in certain dyslipidemias have not been fully elucidated. Here, using high-performance liquid chromatography with a gel filtration column (HPLC-GFC), we have studied the lipoprotein profile of a 17-year old male patient with Tangier disease who to date has not developed manifest coronary atherosclerosis. The patient was shown to be homozygous for a novel mutation (Leu1097Pro) in the central cytoplasmic region of ATP-binding cassette transporter A1 (ABCA1). Serum total and HDL-cholesterol levels were 59mg/dl and 2mg/dl, respectively. Lipoprotein electrophoretic analyses on agarose and polyacrylamide gels showed the presence of massively abnormal lipoproteins. Further analysis by HPLC-GFC identified significant amounts of lipoproteins in low-density lipoprotein (LDL) subfractions. The lipoprotein particles found in the peak subfraction were smaller than normal LDL, were rich in triglycerides, but poor in cholesterol and phospholipids. These findings in an adolescent Tangier patient suggest that patients in whom these triglyceride-rich, cholesterol- and phospholipid-poor LDL-type particles accumulate over time, would experience an increased propensity for developing atherosclerosis.
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205
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Liu M, Zhang W, Li X, Han J, Chen Y, Duan Y. Impact of age and sex on the development of atherosclerosis and expression of the related genes in apoE deficient mice. Biochem Biophys Res Commun 2015; 469:456-62. [PMID: 26592663 DOI: 10.1016/j.bbrc.2015.11.064] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 11/16/2015] [Indexed: 11/29/2022]
Abstract
Development of atherosclerosis is a chronic pathological process. ApoE deficient (apoE(-/-)) mice spontaneously develop atherosclerotic lesions. However, the impact of age and sex on lesions and expression of the related genes have not been fully elucidated. In this study, we collected blood and tissue samples from normal chow fed male and female apoE(-/-) mice at different ages, and determined serum lipids, PCSK9 levels, en face aortic lesions and expression of some pro- or anti-atherogenic genes. We determined that lesion development was clearly associated with age, and more lesions in males than females (12.6 ± 1.7% vs. 8.9 ± 1.1% at 8 months old, P < 0.05). Associated with age, serum total, LDL- and HDL-cholesterol and PCSK9 levels increased with more PCSK9 in females than males (313 ± 31 ng/mL vs. 239 ± 28 ng/mL at 8 months old, P < 0.05); expression of liver LDLR and ABCA1 decreased while of SR-BI increased; expression of macrophage ABCA1 and SR-BI decreased but of CD36 increased. Estrogen and tamoxifen induced ABCA1 and SR-BI expression, respectively, in macrophages isolated from female mice at the different age. Taken together, our study suggests that aging facilitates lesion development in apoE(-/-) mice with greater effect on male mice. The lesion development is also related to expression of pro- or anti-atherogenic genes in tissues, particularly in macrophages.
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Affiliation(s)
- Mengyang Liu
- College of Life Sciences, Nankai University, Tianjin, China
| | - Wenwen Zhang
- College of Life Sciences, Nankai University, Tianjin, China
| | - Xiaoju Li
- College of Life Sciences, Nankai University, Tianjin, China
| | - Jihong Han
- College of Medical Engineering, Hefei University of Technology, Hefei, China; College of Life Sciences, State Key Laboratory of Medicinal Chemical Biology, Collaborative Innovation Center of Biotherapy, Nankai University, Tianjin, China
| | - Yuanli Chen
- College of Medical Engineering, Hefei University of Technology, Hefei, China; School of Medicine, State Key Laboratory of Medicinal Chemical Biology, Collaborative Innovation Center of Biotherapy, Nankai University, Tianjin, China.
| | - Yajun Duan
- College of Medical Engineering, Hefei University of Technology, Hefei, China; College of Life Sciences, State Key Laboratory of Medicinal Chemical Biology, Collaborative Innovation Center of Biotherapy, Nankai University, Tianjin, China.
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206
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LIU JIA, LIU XUEQING, LIU YING, SUN YANAN, LI SI, LI CHUNMEI, LI JIE, TIAN WEI, SHANG XIAOMING, ZHOU YUNTAO. MicroRNA 28-5p regulates ATP-binding cassette transporter A1 via inhibiting extracellular signal-regulated kinase 2. Mol Med Rep 2015; 13:433-40. [DOI: 10.3892/mmr.2015.4563] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 07/29/2015] [Indexed: 11/05/2022] Open
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207
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Fitz NF, Tapias V, Cronican AA, Castranio EL, Saleem M, Carter AY, Lefterova M, Lefterov I, Koldamova R. Opposing effects of Apoe/Apoa1 double deletion on amyloid-β pathology and cognitive performance in APP mice. Brain 2015; 138:3699-715. [PMID: 26510953 DOI: 10.1093/brain/awv293] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Accepted: 08/14/2015] [Indexed: 11/14/2022] Open
Abstract
UNLABELLED ATP binding cassette transporter A1 (encoded by ABCA1) regulates cholesterol efflux from cells to apolipoproteins A-I and E (ApoA-I and APOE; encoded by APOA1 and APOE, respectively) and the generation of high density lipoproteins. In Abca1 knockout mice (Abca1(ko)), high density lipoproteins and ApoA-I are virtually lacking, and total APOE and APOE-containing lipoproteins in brain substantially decreased. As the ε4 allele of APOE is the major genetic risk factor for late-onset Alzheimer's disease, ABCA1 role as a modifier of APOE lipidation is of significance for this disease. Reportedly, Abca1 deficiency in mice expressing human APP accelerates amyloid deposition and behaviour deficits. We used APP/PS1dE9 mice crossed to Apoe and Apoa1 knockout mice to generate Apoe/Apoa1 double-knockout mice. We hypothesized that Apoe/Apoa1 double-knockout mice would mimic the phenotype of APP/Abca1(ko) mice in regards to amyloid plaques and cognitive deficits. Amyloid pathology, peripheral lipoprotein metabolism, cognitive deficits and dendritic morphology of Apoe/Apoa1 double-knockout mice were compared to APP/Abca1(ko), APP/PS1dE9, and single Apoa1 and Apoe knockouts. Contrary to our prediction, the results demonstrate that double deletion of Apoe and Apoa1 ameliorated the amyloid pathology, including amyloid plaques and soluble amyloid. In double knockout mice we show that (125)I-amyloid-β microinjected into the central nervous system cleared at a rate twice faster compared to Abca1 knockout mice. We tested the effect of Apoe, Apoa1 or Abca1 deficiency on spreading of exogenous amyloid-β seeds injected into the brain of young pre-depositing APP mice. The results show that lack of Abca1 augments dissemination of exogenous amyloid significantly more than the lack of Apoe. In the periphery, Apoe/Apoa1 double-knockout mice exhibited substantial atherosclerosis and very high levels of low density lipoproteins compared to APP/PS1dE9 and APP/Abca1(ko). Plasma level of amyloid-β42 measured at several time points for each mouse was significantly higher in Apoe/Apoa1 double-knockout then in APP/Abca1(ko) mice. This result demonstrates that mice with the lowest level of plasma lipoproteins, APP/Abca1(ko), have the lowest level of peripheral amyloid-β. Unexpectedly, and independent of amyloid pathology, the deletion of both apolipoproteins worsened behaviour deficits of double knockout mice and their performance was undistinguishable from those of Abca1 knockout mice. Finally we observed that the dendritic complexity in the CA1 region of hippocampus but not in CA2 is significantly impaired by Apoe/Apoa1 double deletion as well as by lack of ABCA1. IN CONCLUSION (i) plasma lipoproteins may affect amyloid-β clearance from the brain by the 'peripheral sink' mechanism; and (ii) deficiency of brain APOE-containing lipoproteins is of significance for dendritic complexity and cognition.
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Affiliation(s)
- Nicholas F Fitz
- 1 Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Victor Tapias
- 2 Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Andrea A Cronican
- 1 Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Emilie L Castranio
- 1 Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Muzamil Saleem
- 3 Biological Sciences, Bayer School of Natural and Environmental Sciences, Duquesne University, Pittsburgh, PA 15282, USA
| | - Alexis Y Carter
- 1 Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Martina Lefterova
- 4 Department of Pathology, Stanford University, Stanford, CA 94305, USA
| | - Iliya Lefterov
- 1 Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Radosveta Koldamova
- 1 Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA
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208
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Yamauchi Y, Yokoyama S, Chang TY. ABCA1-dependent sterol release: sterol molecule specificity and potential membrane domain for HDL biogenesis. J Lipid Res 2015; 57:77-88. [PMID: 26497474 DOI: 10.1194/jlr.m063784] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Indexed: 01/28/2023] Open
Abstract
Mammalian cells synthesize various sterol molecules, including the C30 sterol, lanosterol, as cholesterol precursors in the endoplasmic reticulum. The build-up of precursor sterols, including lanosterol, displays cellular toxicity. Precursor sterols are found in plasma HDL. How these structurally different sterols are released from cells is poorly understood. Here, we show that newly synthesized precursor sterols arriving at the plasma membrane (PM) are removed by extracellular apoA-I in a manner dependent on ABCA1, a key macromolecule for HDL biogenesis. Analysis of sterol molecules by GC-MS and tracing the fate of radiolabeled acetate-derived sterols in normal and mutant Niemann-Pick type C cells reveal that ABCA1 prefers newly synthesized sterols, especially lanosterol, as the substrates before they are internalized from the PM. We also show that ABCA1 resides in a cholesterol-rich membrane domain resistant to the mild detergent, Brij 98. Blocking ACAT activity increases the cholesterol contents of this domain. Newly synthesized C29/C30 sterols are transiently enriched within this domain, but rapidly disappear from this domain with a half-life of less than 1 h. Our work shows that substantial amounts of precursor sterols are transported to a certain PM domain and are removed by the ABCA1-dependent pathway.
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Affiliation(s)
- Yoshio Yamauchi
- Department of Biochemistry II, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Shinji Yokoyama
- Nutritional Health Science Research Center and Department of Food and Nutritional Sciences, Chubu University, Kasugai 487-8501, Japan
| | - Ta-Yuan Chang
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
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209
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HDL and CER-001 Inverse-Dose Dependent Inhibition of Atherosclerotic Plaque Formation in apoE-/- Mice: Evidence of ABCA1 Down-Regulation. PLoS One 2015; 10:e0137584. [PMID: 26335690 PMCID: PMC4559410 DOI: 10.1371/journal.pone.0137584] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 08/18/2015] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE CER-001 is a novel engineered HDL-mimetic comprised of recombinant human apoA-I and charged phospholipids that was designed to mimic the beneficial properties of nascent pre-ß HDL. In this study, we have evaluated the dose-dependent regulation of ABCA1 expression in vitro and in vivo in the presence of CER-001 and native HDL (HDL3). METHODS AND RESULTS CER-001 induced cholesterol efflux from J774 macrophages in a dose-dependent manner similar to natural HDL. A strong down-regulation of the ATP-binding cassette A1 (ABCA1) transporter mRNA (- 50%) as well as the ABCA1 membrane protein expression (- 50%) was observed at higher doses of CER-001 and HDL3 compared to non-lipidated apoA-I. In vivo, in an apoE-/- mouse "flow cessation model," in which the left carotid artery was ligatured to induce local inflammation, the inhibition of atherosclerotic plaque burden progression in response to a dose-range of every-other-day CER-001 or HDL in the presence of a high-fat diet for two weeks was assessed. We observed a U-shaped dose-response curve: inhibition of the plaque total cholesterol content increased with increasing doses of CER-001 or HDL3 up to a maximum inhibition (- 51%) at 5 mg/kg; however, as the dose was increased above this threshold, a progressively less pronounced inhibition of progression was observed, reaching a complete absence of inhibition of progression at doses of 20 mg/kg and over. ABCA1 protein expression in the same atherosclerotic plaque was decreased by-45% and-68% at 50 mg/kg for CER-001 and HDL respectively. Conversely, a-12% and 0% decrease in ABCA1 protein expression was observed at the 5 mg/kg dose for CER-001 and HDL respectively. CONCLUSIONS These data demonstrate that high doses of HDL and CER-001 are less effective at slowing progression of atherosclerotic plaque in apoE-/- mice compared to lower doses, following a U-shaped dose-response curve. A potential mechanism for this phenomenon is supported by the observation that high doses of HDL and CER-001 induce a rapid and strong down-regulation of ABCA1 both in vitro and in vivo. In conclusion, maximally efficient HDL- or CER-001-mediated cholesterol removal from atherosclerotic plaque is achieved by maximizing macrophage-mediated efflux from the plaque while minimizing dose-dependent down-regulation of ABCA1 expression. These observations may help define the optimal dose of HDL mimetics for testing in clinical trials of atherosclerotic burden regression.
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210
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Lee SD, Tontonoz P. Liver X receptors at the intersection of lipid metabolism and atherogenesis. Atherosclerosis 2015; 242:29-36. [PMID: 26164157 PMCID: PMC4546914 DOI: 10.1016/j.atherosclerosis.2015.06.042] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 06/19/2015] [Accepted: 06/22/2015] [Indexed: 12/14/2022]
Affiliation(s)
- Stephen D Lee
- Howard Hughes Medical Institute, Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA 90095, USA
| | - Peter Tontonoz
- Howard Hughes Medical Institute, Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA 90095, USA.
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211
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Okoro EU, Zhang H, Guo Z, Yang F, Smith C, Yang H. A Subregion of Reelin Suppresses Lipoprotein-Induced Cholesterol Accumulation in Macrophages. PLoS One 2015; 10:e0136895. [PMID: 26317415 PMCID: PMC4552883 DOI: 10.1371/journal.pone.0136895] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 08/10/2015] [Indexed: 11/18/2022] Open
Abstract
Activation of apolipoprotein E receptor-2 (apoER2) and very low density lipoprotein receptor (VLDLR) inhibits foam cell formation. Reelin is a ligand of these receptors. Here we generated two reelin subregions containing the receptor binding domain with or without its C-terminal region (R5-6C and R5-6, respectively) and studied the impact of these peptides on macrophage cholesterol metabolism. We found that both R5-6C and R5-6 can be secreted by cells. Purified R5-6 protein can bind apoER2 and VLDLR. Overexpression of apoER2 in macrophages increased the amount of R5-6 bound to the cell surface. Treatment of macrophages with 0.2 μg/ml R5-6 elevated ATP binding cassette A1 (ABCA1) protein level by ~72% and apoAI-mediated cholesterol efflux by ~39%. In addition, the medium harvested from cells overexpressing R5-6 or R5-6C (R5-6- and R5-6C-conditioned media, respectively) also up-regulated ABCA1 protein expression, which was associated with accelerated cholesterol efflux and enhanced phosphorylation of phosphatidylinositol 3 kinase (PI3K) and specificity protein-1 (Sp1) in macrophages. The increased ABCA1 expression and cholesterol efflux by R5-6- and R5-6C-conditioned media were diminished by Sp1 or PI3K inhibitors mithramycin A and LY294002. Further, the cholesterol accumulation induced by apoB-containing, apoE-free lipoproteins was significantly less in macrophages incubated with R5-6- or R5-6C-conditioned medium than in those incubated with control conditioned medium. Knockdown of apoER2 or VLDLR attenuated the inhibitory role of R5-6-conditioned medium against lipoprotein-induced cholesterol accumulation. These results suggest that the reelin subregion R5-6 can serve as a tool for studying the role of apoER2 and VLDLR in atherogenesis.
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Affiliation(s)
- Emmanuel U. Okoro
- Department of Physiology, Meharry Medical College, Nashville, Tennessee, United States of America
| | - Hongfeng Zhang
- Department of Physiology, Meharry Medical College, Nashville, Tennessee, United States of America
- Department of Pathology, Central Hospital of Wuhan, Wuhan City, People’s Republic of China
| | - Zhongmao Guo
- Department of Physiology, Meharry Medical College, Nashville, Tennessee, United States of America
| | - Fang Yang
- Department of Physiology, Meharry Medical College, Nashville, Tennessee, United States of America
- Wuhan University School of Basic Medical Science, Wuhan City, People’s Republic of China
| | - Carlie Smith
- Department of Physiology, Meharry Medical College, Nashville, Tennessee, United States of America
| | - Hong Yang
- Department of Physiology, Meharry Medical College, Nashville, Tennessee, United States of America
- * E-mail:
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212
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Bag-Ozbek A, Giles JT. Inflammation, adiposity, and atherogenic dyslipidemia in rheumatoid arthritis: is there a paradoxical relationship? Curr Allergy Asthma Rep 2015; 15:497. [PMID: 25504261 DOI: 10.1007/s11882-014-0497-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Dyslipidemia is highly prevalent in rheumatoid arthritis (RA) and appears to be present very early in the RA disease process, in some studies even before a diagnosis of clinical RA has been made. The association between lipid measures and the risk of cardiovascular disease (CVD) in RA appears to be paradoxical, whereby lower levels of total cholesterol (TC), low-density lipoprotein (LDL-C), and atherogenic ratios are associated with higher CVD risk. This may be due to the lipid-lowering effects of RA-related systemic inflammation. Therefore, standard CVD risk calculators have been shown to underperform in RA. Data also suggest that lipoprotein particle sizes and the apolipoprotein cargo of lipoproteins skew toward atherogenic dyslipidemia in RA and may contribute to the initiation and progression of atherosclerosis. Inflammatory burden in RA may also alter the anti-inflammatory and atheroprotective roles associated with high-density lipoprotein cholesterol (HDL-C). Adipose tissue is quantitatively increased in RA patients compared with matched non-RA controls and may be more inflamed and metabolically dysfunctional compared with an otherwise similar non-RA patient. In vitro, animal, and a handful of non-RA human, studies suggest that inflamed, metabolically dysfunctional adipose tissue contributes directly to lower HDL-C levels. In turn, lower HDL-C that has been altered functionally by inflammation may lead to expanded adipose mass and further adipose dysfunction and inflammation. In the last part of this review, we speculate how the RA disease state may recapitulate these processes.
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Affiliation(s)
- Ayse Bag-Ozbek
- Division of Rheumatology, College of Physicians and Surgeons, Columbia University, 630 W 168th St, Physicians and Surgeons Building, Suite 10-445, New York, NY, 10032, USA
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213
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Segrest JP, Jones MK, Catte A, Manchekar M, Datta G, Zhang L, Zhang R, Li L, Patterson JC, Palgunachari MN, Oram JF, Ren G. Surface Density-Induced Pleating of a Lipid Monolayer Drives Nascent High-Density Lipoprotein Assembly. Structure 2015; 23:1214-26. [PMID: 26095027 PMCID: PMC4496276 DOI: 10.1016/j.str.2015.05.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 04/22/2015] [Accepted: 05/05/2015] [Indexed: 11/28/2022]
Abstract
Biogenesis of high-density lipoproteins (HDL) is coupled to the transmembrane protein, ATP-binding cassette transporter A1 (ABCA1), which transports phospholipid (PL) from the inner to the outer membrane monolayer. Using a combination of computational and experimental approaches, we show that increased outer lipid monolayer surface density, driven by excess PL or membrane insertion of amphipathic helices, results in pleating of the outer monolayer to form membrane-attached discoidal bilayers. Apolipoprotein (apo)A-I accelerates and stabilizes the pleats. In the absence of apoA-I, pleats collapse to form vesicles. These results mimic cells overexpressing ABCA1 that, in the absence of apoA-I, form and release vesicles. We conclude that the basic driving force for nascent discoidal HDL assembly is a PL pump-induced surface density increase that produces lipid monolayer pleating. We then argue that ABCA1 forms an extracellular reservoir containing an isolated pressurized lipid monolayer decoupled from the transbilayer density buffering of cholesterol.
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Affiliation(s)
- Jere P Segrest
- Department of Medicine and Atherosclerosis Research Unit, University of Alabama at Birmingham, Birmingham, AL 35294-0012, USA; Center for Computational and Structural Dynamics, 630 BDB, UAB, Birmingham, AL 35294, USA.
| | - Martin K Jones
- Department of Medicine and Atherosclerosis Research Unit, University of Alabama at Birmingham, Birmingham, AL 35294-0012, USA; Center for Computational and Structural Dynamics, 630 BDB, UAB, Birmingham, AL 35294, USA
| | - Andrea Catte
- Department of Medicine and Atherosclerosis Research Unit, University of Alabama at Birmingham, Birmingham, AL 35294-0012, USA; Center for Computational and Structural Dynamics, 630 BDB, UAB, Birmingham, AL 35294, USA
| | - Medha Manchekar
- Department of Medicine and Atherosclerosis Research Unit, University of Alabama at Birmingham, Birmingham, AL 35294-0012, USA
| | - Geeta Datta
- Department of Medicine and Atherosclerosis Research Unit, University of Alabama at Birmingham, Birmingham, AL 35294-0012, USA
| | - Lei Zhang
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Robin Zhang
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Ling Li
- Department of Medicine and Atherosclerosis Research Unit, University of Alabama at Birmingham, Birmingham, AL 35294-0012, USA
| | - James C Patterson
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL 35294-0012, USA
| | - Mayakonda N Palgunachari
- Department of Medicine and Atherosclerosis Research Unit, University of Alabama at Birmingham, Birmingham, AL 35294-0012, USA
| | - Jack F Oram
- Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Gang Ren
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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214
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Qi LP, Chen LF, Dang AM, Li LY, Fang Q, Yan XW. Association between the ABCA1-565C/T gene promoter polymorphism and coronary heart disease severity and cholesterol efflux in the Chinese Han population. Genet Test Mol Biomarkers 2015; 19:347-52. [PMID: 26090796 DOI: 10.1089/gtmb.2015.0011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND ABCA1 -565C/T gene promoter variants have been associated with the severity of coronary artery disease in Western populations. The purpose of our study was to investigate the association between the -565C/T gene polymorphism and coronary artery disease severity and cholesterol efflux in the Chinese Han population. METHODS A cohort of 298 acute coronary syndrome (ACS) patients and 541 healthy controls was genotyped using the highly sensitive ligase detection reaction. ABCA1 -565C/T genotype was correlated with the clinical features of 164 acute myocardial infarction (AMI) patients. Monocytes from patients with various -565C/T gene polymorphisms were isolated and differentiated into foam cells by coincubation with [(3)H]-labeled acetyl-low-density lipoprotein cholesterol. ABCA1 mRNA and protein expression levels were evaluated, as well as cellular cholesterol efflux. RESULTS The frequency of the TT genotype in the -565C/T polymorphism of ACS patients was significantly increased when compared with controls (0.211 vs. 0.162, p<0.05). The TT genotype, but not the CT or CC genotypes, in the -565C/T gene polymorphism correlated with the severity of the coronary lesion observed in AMI patients. Patients with the TT homozygote genotype also exhibited significantly lower cellular cholesterol efflux (TT [6.37%±0.554%]) levels than controls and also had the lowest levels of ABCA1 mRNA and protein expression among the group of variants. In contrast, cholesterol efflux levels in AMI patients with CT [11.35%±3.975%] and CC ([15.32%±6.293%]) genotypes were not significantly different from controls. CONCLUSIONS Impaired ABCA1-mediated cholesterol efflux in macrophages may be associated with the severity of the coronary lesions in AMI patients with the TT genotype at the -565C/T gene polymorphism.
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Affiliation(s)
- Li-Ping Qi
- 1 Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College , Chinese Academy of Medicine Science, Beijing, China
- 2 Department of Second Geriatric Cardiology, The People's Liberation Army General Hospital , Beijing, China
| | - Lian-Feng Chen
- 1 Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College , Chinese Academy of Medicine Science, Beijing, China
| | - Ai-Min Dang
- 3 Department of Cardiology, FuWai Cardiovascular Disease Hospital, Peking Union Medical College , Chinese Academy of Medicine Science, Beijing, China
| | - Li-Yun Li
- 1 Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College , Chinese Academy of Medicine Science, Beijing, China
| | - Quan Fang
- 1 Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College , Chinese Academy of Medicine Science, Beijing, China
| | - Xiao-Wei Yan
- 1 Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College , Chinese Academy of Medicine Science, Beijing, China
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Fond AM, Lee CS, Schulman IG, Kiss RS, Ravichandran KS. Apoptotic cells trigger a membrane-initiated pathway to increase ABCA1. J Clin Invest 2015; 125:2748-58. [PMID: 26075824 DOI: 10.1172/jci80300] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 05/12/2015] [Indexed: 01/15/2023] Open
Abstract
Macrophages clear millions of apoptotic cells daily and, during this process, take up large quantities of cholesterol. The membrane transporter ABCA1 is a key player in cholesterol efflux from macrophages and has been shown via human genetic studies to provide protection against cardiovascular disease. How the apoptotic cell clearance process is linked to macrophage ABCA1 expression is not known. Here, we identified a plasma membrane-initiated signaling pathway that drives a rapid upregulation of ABCA1 mRNA and protein. This pathway involves the phagocytic receptor brain-specific angiogenesis inhibitor 1 (BAI1), which recognizes phosphatidylserine on apoptotic cells, and the intracellular signaling intermediates engulfment cell motility 1 (ELMO1) and Rac1, as ABCA1 induction was attenuated in primary macrophages from mice lacking these molecules. Moreover, this apoptotic cell-initiated pathway functioned independently of the liver X receptor (LXR) sterol-sensing machinery that is known to regulate ABCA1 expression and cholesterol efflux. When placed on a high-fat diet, mice lacking BAI1 had increased numbers of apoptotic cells in their aortic roots, which correlated with altered lipid profiles. In contrast, macrophages from engineered mice with transgenic BAI1 overexpression showed greater ABCA1 induction in response to apoptotic cells compared with those from control animals. Collectively, these data identify a membrane-initiated pathway that is triggered by apoptotic cells to enhance ABCA1 within engulfing phagocytes and with functional consequences in vivo.
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216
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ZHOU LINGYAN, LI CONGCONG, GAO LING, WANG AIHONG. High-density lipoprotein synthesis and metabolism (Review). Mol Med Rep 2015; 12:4015-4021. [DOI: 10.3892/mmr.2015.3930] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 03/26/2015] [Indexed: 11/06/2022] Open
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217
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Cellular Cholesterol Accumulation Facilitates Ubiquitination and Lysosomal Degradation of Cell Surface–Resident ABCA1. Arterioscler Thromb Vasc Biol 2015; 35:1347-56. [DOI: 10.1161/atvbaha.114.305182] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 03/24/2015] [Indexed: 11/16/2022]
Abstract
Objective—
By excreting cellular cholesterol to apolipoprotein A-I, ATP-binding cassette transporter A1 (ABCA1) mediates the biogenesis of high-density lipoprotein in hepatocytes and prevents foam cell formation from macrophages. We recently showed that cell surface–resident ABCA1 (csABCA1) undergoes ubiquitination and later lysosomal degradation through the endosomal sorting complex required for transport system. Herein, we investigated the relevance of this degradation pathway to the turnover of csABCA1 in hypercholesterolemia.
Approach and Results—
Immunoprecipitation and cell surface-biotinylation studies with HepG2 cells and mouse peritoneal macrophages showed that the ubiquitination level and degradation of csABCA1 were facilitated by treatment with a liver X receptor (LXR) agonist and acetylated low-density lipoprotein. The effects of an LXR agonist and acetylated low-density lipoprotein on the degradation of csABCA1 were repressed completely by treatment with bafilomycin, an inhibitor of lysosomal degradation, and by depletion of tumor susceptibility gene 101, a major component of endosomal sorting complex required for transport-I. RNAi analysis indicated that LXRβ inhibited the accelerated lysosomal degradation of csABCA1 by the LXR agonist, regardless of its transcriptional activity. Cell surface coimmunoprecipitation with COS1 cells expressing extracellularly hemagglutinin-tagged ABCA1 showed that LXRβ interacted with csABCA1 and inhibited the ubiquitination of csABCA1. Immunoprecipitates with anti-ABCA1 antibodies from the liver plasma membranes showed less LXRβ and a higher ubiquitination level of ABCA1 in high-fat diet–fed mice than in normal chow-fed mice.
Conclusions—
Under conditions of high cellular cholesterol content, csABCA1 became susceptible to ubiquitination by dissociation of LXRβ from csABCA1, which facilitated the lysosomal degradation of csABCA1 through the endosomal sorting complex required for transport system.
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218
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Tada H, Kawashiri MA, Nohara A, Saito R, Tanaka Y, Nomura A, Konno T, Sakata K, Fujino N, Takamura T, Inazu A, Mabuchi H, Yamagishi M, Hayashi K. Whole exome sequencing combined with integrated variant annotation prediction identifies asymptomatic Tangier disease with compound heterozygous mutations in ABCA1 gene. Atherosclerosis 2015; 240:324-9. [DOI: 10.1016/j.atherosclerosis.2015.04.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/08/2015] [Accepted: 04/02/2015] [Indexed: 12/30/2022]
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219
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Itoh S, Nagao K, Kimura Y, Matsuo M, Kioka N, Ueda K. Position 834 in TM6 plays an important role in cholesterol and phosphatidylcholine transport by ABCA1. Biosci Biotechnol Biochem 2015; 79:775-81. [DOI: 10.1080/09168451.2014.993358] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Abstract
ATP-binding cassette protein A1 (ABCA1) plays a key role in eliminating excess cholesterol from peripheral cells by generating nascent high-density lipoprotein (HDL). However, it remains unclear whether both phospholipids and cholesterol are directly loaded onto apolipoprotein A-I (apoA-I) by ABCA1. To identify the amino acid residues of ABCA1 involved in substrate recognition and transport, we applied arginine scan mutagenesis to residues L821–E843 of human ABCA1 and predicted the environment to which each residue is exposed. The relative surface expression of each mutant suggested that residues L821–E843 pass through the plasma membrane as TM6, and the four residues (S826, F830, L834, and V837) of TM6 are exposed to the hydrophilic internal cavity of ABCA1. Furthermore, we showed that L834 is critical for the function of ABCA1.
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Affiliation(s)
- Shimpei Itoh
- Laboratory of Cellular Biochemistry, Division of Applied Life Sciences, Kyoto University Graduate School of Agriculture, Kyoto, Japan
| | - Kohjiro Nagao
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Kyoto, Japan
| | - Yasuhisa Kimura
- Laboratory of Cellular Biochemistry, Division of Applied Life Sciences, Kyoto University Graduate School of Agriculture, Kyoto, Japan
| | - Michinori Matsuo
- Laboratory of Cellular Biochemistry, Division of Applied Life Sciences, Kyoto University Graduate School of Agriculture, Kyoto, Japan
| | - Noriyuki Kioka
- Laboratory of Cellular Biochemistry, Division of Applied Life Sciences, Kyoto University Graduate School of Agriculture, Kyoto, Japan
| | - Kazumitsu Ueda
- Laboratory of Cellular Biochemistry, Division of Applied Life Sciences, Kyoto University Graduate School of Agriculture, Kyoto, Japan
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Kyoto, Japan
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220
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Ulatowski LM, Manor D. Vitamin E and neurodegeneration. Neurobiol Dis 2015; 84:78-83. [PMID: 25913028 DOI: 10.1016/j.nbd.2015.04.002] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/07/2015] [Accepted: 04/15/2015] [Indexed: 12/22/2022] Open
Abstract
Alpha-tocopherol (vitamin E) is a plant-derived antioxidant that is essential for human health. Studies with humans and with animal models of vitamin E deficiency established the critical roles of the vitamin in protecting the central nervous system, and especially the cerebellum, from oxidative damage and motor coordination deficits. We review here the established roles of vitamin E in protecting cerebellar functions, as well as emerging data demonstrating the critical roles of alpha-tocopherol in preserving learning, memory and emotive responses. We also discuss the importance of vitamin E adequacy in seemingly unrelated neurological disorders.
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Affiliation(s)
- Lynn M Ulatowski
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Danny Manor
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
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221
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Brunham LR, Hayden MR. Human genetics of HDL: Insight into particle metabolism and function. Prog Lipid Res 2015; 58:14-25. [DOI: 10.1016/j.plipres.2015.01.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 12/22/2014] [Accepted: 01/07/2015] [Indexed: 10/24/2022]
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222
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Johnson P, Kuritzky J, Runge M. The Genetics of Atherosclerosis. Atherosclerosis 2015. [DOI: 10.1002/9781118828533.ch7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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223
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Gillespie MA, Gold ES, Ramsey SA, Podolsky I, Aderem A, Ranish JA. An LXR-NCOA5 gene regulatory complex directs inflammatory crosstalk-dependent repression of macrophage cholesterol efflux. EMBO J 2015; 34:1244-58. [PMID: 25755249 DOI: 10.15252/embj.201489819] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 02/13/2015] [Indexed: 02/04/2023] Open
Abstract
LXR-cofactor complexes activate the gene expression program responsible for cholesterol efflux in macrophages. Inflammation antagonizes this program, resulting in foam cell formation and atherosclerosis; however, the molecular mechanisms underlying this antagonism remain to be fully elucidated. We use promoter enrichment-quantitative mass spectrometry (PE-QMS) to characterize the composition of gene regulatory complexes assembled at the promoter of the lipid transporter Abca1 following downregulation of its expression. We identify a subset of proteins that show LXR ligand- and binding-dependent association with the Abca1 promoter and demonstrate they differentially control Abca1 expression. We determine that NCOA5 is linked to inflammatory Toll-like receptor (TLR) signaling and establish that NCOA5 functions as an LXR corepressor to attenuate Abca1 expression. Importantly, TLR3-LXR signal crosstalk promotes recruitment of NCOA5 to the Abca1 promoter together with loss of RNA polymerase II and reduced cholesterol efflux. Together, these data significantly expand our knowledge of regulatory inputs impinging on the Abca1 promoter and indicate a central role for NCOA5 in mediating crosstalk between pro-inflammatory and anti-inflammatory pathways that results in repression of macrophage cholesterol efflux.
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Affiliation(s)
| | | | - Stephen A Ramsey
- Department of Biomedical Sciences, Oregon State University, Corvallis, OR, USA
| | | | - Alan Aderem
- Seattle Biomedical Research Institute, Seattle, WA, USA
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224
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Antoniu S. Fresh from the designation pipeline: orphan drugs recently designated in the European Union (August–October 2014). Expert Opin Orphan Drugs 2015. [DOI: 10.1517/21678707.2015.1016909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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225
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Genetic variability in drug transport, metabolism or DNA repair affecting toxicity of chemotherapy in ovarian cancer. BMC Pharmacol Toxicol 2015; 16:2. [PMID: 25881102 PMCID: PMC4359565 DOI: 10.1186/s40360-015-0001-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 02/11/2015] [Indexed: 12/26/2022] Open
Abstract
Background This study aimed to determine whether single nucleotide polymorphisms (SNPs) in genes involved in DNA repair or metabolism of taxanes or platinum could predict toxicity or response to first-line chemotherapy in ovarian cancer. Methods Twenty-six selected SNPs in 18 genes were genotyped in 322 patients treated with first-line paclitaxel-carboplatin or carboplatin mono-therapy. Genotypes were correlated with toxicity events (anemia, neutropenia, thrombocytopenia, febrile neutropenia, neurotoxicity), use of growth factors and survival. Results The risk of anemia was increased for variant alleles of rs1128503 (ABCB1, C > T; p = 0.023, OR = 1.71, 95% CI = 1.07-2.71), rs363717 (ABCA1, A > G; p = 0.002, OR = 2.08, 95% CI = 1.32-3.27) and rs11615 (ERCC1, T > C; p = 0.031, OR = 1.61, 95% CI = 1.04-2.50), while it was decreased for variant alleles of rs12762549 (ABCC2, C > G; p = 0.004, OR = 0.51, 95% CI = 0.33-0.81). Likewise, increased risk of thrombocytopenia was associated with rs4986910 (CYP3A4, T > C; p = 0.025, OR = 4.99, 95% CI = 1.22-20.31). No significant correlations were found for neurotoxicity. Variant alleles of rs2073337 (ABCC2, A > G; p = 0.039, OR = 0.60, 95% CI = 0.37-0.98), rs1695 (ABCC1, A > G; p = 0.017, OR = 0.55, 95% CI 0.33-0.90) and rs1799793 (ERCC2, G > A; p = 0.042, OR = 0.63, 95% CI 0.41-0.98) associated with the use of colony stimulating factors (CSF), while rs2074087 (ABCC1, G > C; p = 0.011, OR = 2.09, 95% CI 1.18-3.68) correlated with use of erythropoiesis stimulating agents (ESAs). Homozygous carriers of the rs1799793 (ERCC2, G > A) G-allele had a prolonged platinum-free interval (p = 0.016). Conclusions Our data reveal significant correlations between genetic variants of transport, hepatic metabolism, platinum related detoxification or DNA damage repair and toxicity or outcome in ovarian cancer. Electronic supplementary material The online version of this article (doi:10.1186/s40360-015-0001-5) contains supplementary material, which is available to authorized users.
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226
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Hotta N, Abe-Dohmae S, Taguchi R, Yokoyama S. Preferential incorporation of shorter and less unsaturated acyl phospholipids into high density lipoprotein-like particles in the ABCA1- and ABCA7-mediated biogenesis with apoA-I. Chem Phys Lipids 2015; 187:1-9. [PMID: 25665932 DOI: 10.1016/j.chemphyslip.2015.01.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 01/24/2015] [Accepted: 01/27/2015] [Indexed: 11/27/2022]
Abstract
Molecular species of phosphatidylcholine (PC) and sphingomyelin (SPM) were globally analyzed for lipidomics in the nascent high-density lipoprotein (HDL)-like particles generated with human apolipoprotein A-I (apoA-I) form HEK293 cells where either human ATP binding cassette transporter (ABC) A1 or ABCA7 was transfected and overexpressed. SPM/PC ratio was higher in the ABCA1-mediated HDL than ABCA7-mediated HDL likely being related to their cholesterol content, while it was less than the ratio in the cell membrane in either case. Molecular species composition of hydrocarbon chain moiety in each phospholipid in the HDL largely reflected that in the cells the lipoprotein originated in, without remarkable difference between ABCA1 and ABCA7. Further analysis, however, revealed apparent preference for the molecules with shorter hydrocarbon chain length for both PC and SPM in their relative incorporation into HDL by ABCA1 and ABCA7. Likewise, it was in favor for less-unsaturated hydrocarbon chains of PC while this preference was not apparent for SPM. The results are consistent with the view that assembly of HDL particles with extracellular apoA-I is primarily with the cellular phospholipid molecules being regulated in part by their physicochemical nature.
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Affiliation(s)
- Noriko Hotta
- Graduate Schools of Pharmaceutical Sciences, Nagoya, Japan; Medical Sciences, Nagoya City University, Nagoya, Japan
| | | | - Ryo Taguchi
- Graduate Schools of Pharmaceutical Sciences, Nagoya, Japan; Nutritional Health Science Research Center, Chubu University, Kasugai, Japan
| | - Shinji Yokoyama
- Nutritional Health Science Research Center, Chubu University, Kasugai, Japan.
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227
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Levinson SS, Wagner SG. Implications of reverse cholesterol transport: Recent studies. Clin Chim Acta 2015; 439:154-61. [DOI: 10.1016/j.cca.2014.10.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 10/10/2014] [Accepted: 10/11/2014] [Indexed: 11/25/2022]
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228
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ATP-binding cassette transporter 1 C69T and V825I polymorphisms in the development of atherosclerosis: A meta-analysis of 18,320 subjects. Thromb Res 2015; 135:130-6. [DOI: 10.1016/j.thromres.2014.10.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 10/14/2014] [Accepted: 10/27/2014] [Indexed: 11/15/2022]
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229
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Karabina S, Ninio E. Plasma PAFAH/PLA2G7 Genetic Variability, Cardiovascular Disease, and Clinical Trials. ACTA ACUST UNITED AC 2015; 38:145-55. [DOI: 10.1016/bs.enz.2015.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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230
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Molday RS. Insights into the Molecular Properties of ABCA4 and Its Role in the Visual Cycle and Stargardt Disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 134:415-31. [DOI: 10.1016/bs.pmbts.2015.06.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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231
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Abstract
High-density lipoprotein (HDL) is considered to be an anti-atherogenic lipoprotein moiety. Generation of genetically modified (total body and tissue-specific knockout) mouse models has significantly contributed to our understanding of HDL function. Here we will review data from knockout mouse studies on the importance of HDL's major alipoprotein apoA-I, the ABC transporters A1 and G1, lecithin:cholesterol acyltransferase, phospholipid transfer protein, and scavenger receptor BI for HDL's metabolism and its protection against atherosclerosis in mice. The initial generation and maturation of HDL particles as well as the selective delivery of its cholesterol to the liver are essential parameters in the life cycle of HDL. Detrimental atherosclerosis effects observed in response to HDL deficiency in mice cannot be solely attributed to the low HDL levels per se, as the low HDL levels are in most models paralleled by changes in non-HDL-cholesterol levels. However, the cholesterol efflux function of HDL is of critical importance to overcome foam cell formation and the development of atherosclerotic lesions in mice. Although HDL is predominantly studied for its atheroprotective action, the mouse data also suggest an essential role for HDL as cholesterol donor for steroidogenic tissues, including the adrenals and ovaries. Furthermore, it appears that a relevant interaction exists between HDL-mediated cellular cholesterol efflux and the susceptibility to inflammation, which (1) provides strong support for the novel concept that inflammation and metabolism are intertwining biological processes and (2) identifies the efflux function of HDL as putative therapeutic target also in other inflammatory diseases than atherosclerosis.
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Affiliation(s)
- Menno Hoekstra
- Division of Biopharmaceutics, Gorlaeus Laboratories, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, 2333CC, Leiden, The Netherlands,
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232
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Medical Management of Serum Lipids and Coronary Heart Disease. Coron Artery Dis 2015. [DOI: 10.1007/978-1-4471-2828-1_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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233
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Abstract
Numerous epidemiologic studies revealed that high-density lipoprotein (HDL) is an important risk factor for coronary heart disease. There are several well-documented HDL functions such as reversed cholesterol transport, inhibition of inflammation, or inhibition of platelet activation that may account for the atheroprotective effects of this lipoprotein. Mechanistically, these functions are carried out by a direct interaction of HDL particle or its components with receptors localized on the cell surface followed by generation of intracellular signals. Several HDL-associated receptor ligands such as apolipoprotein A-I (apoA-I) or sphingosine-1-phosphate (S1P) have been identified in addition to HDL holoparticles, which interact with surface receptors such as ATP-binding cassette transporter A1 (ABCA1); S1P receptor types 1, 2, and 3 (S1P1, S1P2, and S1P3); or scavenger receptor type I (SR-BI) and activate intracellular signaling cascades encompassing kinases, phospholipases, trimeric and small G-proteins, and cytoskeletal proteins such as actin or junctional protein such as connexin43. In addition, depletion of plasma cell cholesterol mediated by ABCA1, ATP-binding cassette transporter G1 (ABCG1), or SR-BI was demonstrated to indirectly inhibit signaling over proinflammatory or proliferation-stimulating receptors such as Toll-like or growth factor receptors. The present review summarizes the current knowledge regarding the HDL-induced signal transduction and its relevance to athero- and cardioprotective effects as well as other physiological effects exerted by HDL.
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234
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Lo J, Rosenberg ES, Fitzgerald ML, Bazner SB, Ihenachor EJ, Hawxhurst V, Borkowska AH, Wei J, Zimmerman CO, Burdo TH, Williams KC, Freeman MW, Grinspoon SK. High-density lipoprotein-mediated cholesterol efflux capacity is improved by treatment with antiretroviral therapy in acute human immunodeficiency virus infection. Open Forum Infect Dis 2014; 1:ofu108. [PMID: 25734176 PMCID: PMC4324225 DOI: 10.1093/ofid/ofu108] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 11/13/2014] [Indexed: 11/17/2022] Open
Abstract
Background Individuals infected with human immunodeficiency virus (HIV) have decreased high-density lipoprotein (HDL)-cholesterol and increased cardiovascular disease (CVD). Reverse cholesterol transport from macrophages may be inhibited by HIV and contribute to increased CVD. Human studies have not investigated longitudinal effects of HIV and antiretroviral therapy (ART) on cholesterol efflux. Methods Subjects with acute HIV infection were randomized to ART or not. Cholesterol efflux capacity was determined ex vivo after exposure of murine macrophages to apolipoprotein B-depleted patient sera obtained at baseline and after 12 weeks. Results After 12 weeks, HIV RNA decreased most in subjects randomized to ART. Available data on cholesterol demonstrated that efflux capacity from Abca1+/+ macrophages was increased most by sera obtained from ART-treated subjects (20.5% ± 5.0% to 24.3 % ± 6.9%, baseline to 12 weeks, P = .007; ART group [n = 6] vs 18.0 % ± 3.9% to 19.1 % ± 2.9%, baseline to 12 weeks, P = .30; untreated group [n = 6] [P = .04 ART vs untreated group]). Change in HIV RNA was negatively associated with change in Abca1+/+ macrophage cholesterol efflux (r = − 0.62, P = .03), and this finding remained significant (P = .03) after controlling for changes in HDL-cholesterol, CD4+ cells, and markers of monocyte or macrophage activation. Conclusions In subjects acutely infected with HIV, ATP-binding cassette transporter A1-mediated cholesterol efflux was stimulated to a greater degree over time by apolipoprotein B-depleted serum from subjects randomized to ART. The improvement in cholesterol efflux capacity is independently related to reduction in viral load.
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Affiliation(s)
- Janet Lo
- Program in Nutritional Metabolism
| | | | | | - Suzane B Bazner
- Division of Infectious Diseases, Massachusetts General Hospital and Harvard Medical School , Boston
| | | | | | | | | | | | | | | | - Mason W Freeman
- Lipid Metabolism Unit/Center for Computational and Integrative Biology
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235
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Wong JH, Halliday GM, Kim WS. Exploring myelin dysfunction in multiple system atrophy. Exp Neurobiol 2014; 23:337-44. [PMID: 25548533 PMCID: PMC4276804 DOI: 10.5607/en.2014.23.4.337] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 10/15/2014] [Accepted: 10/15/2014] [Indexed: 11/19/2022] Open
Abstract
Multiple system atrophy (MSA) is a rare, yet fatal neurodegenerative disease that presents clinically with autonomic failure in combination with parkinsonism or cerebellar ataxia. MSA impacts on the autonomic nervous system affecting blood pressure, heart rate and bladder function, and the motor system affecting balance and muscle movement. The cause of MSA is unknown, no definitive risk factors have been identified, and there is no cure or effective treatment. The definitive pathology of MSA is the presence of α-synuclein aggregates in the brain and therefore MSA is classified as an α-synucleinopathy, together with Parkinson's disease and dementia with Lewy bodies. Although the molecular mechanisms of misfolding, fibrillation and aggregation of α-synuclein partly overlap with other α-synucleinopathies, the pathological pathway of MSA is unique in that the principal site for α-synuclein deposition is in the oligodendrocytes rather than the neurons. The sequence of pathological events of MSA is now recognized as abnormal protein redistributions in oligodendrocytes first, followed by myelin dysfunction and then neurodegeneration. Oligodendrocytes are responsible for the production and maintenance of myelin, the specialized lipid membrane that encases the axons of all neurons in the brain. Myelin is composed of lipids and two prominent proteins, myelin basic protein and proteolipid protein. In vitro studies suggest that aberration in protein distribution and lipid transport may lead to myelin dysfunction in MSA. The purpose of this perspective is to bring together available evidence to explore the potential role of α-synuclein, myelin protein dysfunction, lipid dyshomeostasis and ABCA8 in MSA pathogenesis.
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Affiliation(s)
- Joanna H Wong
- Neuroscience Research Australia, Sydney, NSW 2031, Australia. ; School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Glenda M Halliday
- Neuroscience Research Australia, Sydney, NSW 2031, Australia. ; School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Woojin Scott Kim
- Neuroscience Research Australia, Sydney, NSW 2031, Australia. ; School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
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de Haan W, Karasinska JM, Ruddle P, Hayden MR. Hepatic ABCA1 expression improves β-cell function and glucose tolerance. Diabetes 2014; 63:4076-82. [PMID: 25028523 DOI: 10.2337/db14-0548] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Low HDL is a risk factor for the development of type 2 diabetes. Hepatic ABCA1 is the rate-limiting protein in HDL biogenesis, and mice lacking hepatic ABCA1 (ABCA1(-l/-l)) have very low plasma HDL concentrations. To investigate the role of hepatic ABCA1 in glucose tolerance and β-cell function, we used ABCA1(-l/-l) mice, which showed impaired glucose tolerance without changes in insulin sensitivity. Insulin secretion was reduced following glucose gavage. Ex vivo, glucose stimulated insulin secretion from β-cells from wild-type (WT) and ABCA1(-l/-l) mice was similar. Insulin secretion was, however, reduced upon addition of ABCA1(-l/-l) serum to the medium compared with WT serum, whereas islets lacking β-cell ABCA1 were not affected differently by ABCA1(-l/-l) or WT serum. After high-fat feeding, WT and ABCA1(-l/-l) mice showed no difference in glucose tolerance or insulin secretion, and serum from ABCA1(-l/-l) and WT mice fed a high-fat diet did not affect insulin secretion differently. We conclude that hepatic ABCA1 improves glucose tolerance by improving β-cell function through both HDL production and interaction with β-cell ABCA1. The beneficial effect of hepatic ABCA1 is decreased under metabolic stress. Increasing hepatic ABCA1 may represent a novel therapeutic strategy for improving glucose homeostasis in diabetes.
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Affiliation(s)
- Willeke de Haan
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Joanna M Karasinska
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Piers Ruddle
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
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237
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Akt inhibition promotes ABCA1-mediated cholesterol efflux to ApoA-I through suppressing mTORC1. PLoS One 2014; 9:e113789. [PMID: 25415591 PMCID: PMC4240609 DOI: 10.1371/journal.pone.0113789] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 10/29/2014] [Indexed: 02/06/2023] Open
Abstract
ATP-binding cassette transporter A1 (ABCA1) plays an essential role in mediating cholesterol efflux to apolipoprotein A-I (apoA-I), a major housekeeping mechanism for cellular cholesterol homeostasis. After initial engagement with ABCA1, apoA-I directly interacts with the plasma membrane to acquire cholesterol. This apoA-I lipidation process is also known to require cellular signaling processes, presumably to support cholesterol trafficking to the plasma membrane. We report here that one of major signaling pathways in mammalian cells, Akt, is also involved. In several cell models that express ABCA1 including macrophages, pancreatic beta cells and hepatocytes, inhibition of Akt increases cholesterol efflux to apoA-I. Importantly, Akt inhibition has little effect on cells expressing non-functional mutant of ABCA1, implicating a specific role of Akt in ABCA1 function. Furthermore, we provide evidence that mTORC1, a major downstream target of Akt, is also a negative regulator of cholesterol efflux. In cells where mTORC1 is constitutively activated due to tuberous sclerosis complex 2 deletion, cholesterol efflux to apoA-I is no longer sensitive to Akt activity. This suggests that Akt suppresses cholesterol efflux through mTORC1 activation. Indeed, inhibition of mTORC1 by rapamycin or Torin-1 promotes cholesterol efflux. On the other hand, autophagy, one of the major pathways of cholesterol trafficking, is increased upon Akt inhibition. Furthermore, Akt inhibition disrupts lipid rafts, which is known to promote cholesterol efflux to apoA-I. We therefore conclude that Akt, through its downstream targets, mTORC1 and hence autophagy, negatively regulates cholesterol efflux to apoA-I.
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238
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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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239
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Pahnke J, Fröhlich C, Paarmann K, Krohn M, Bogdanovic N, Årsland D, Winblad B. Cerebral ABC Transporter-common Mechanisms May Modulate Neurodegenerative Diseases and Depression in Elderly Subjects. Arch Med Res 2014; 45:738-43. [DOI: 10.1016/j.arcmed.2014.10.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 10/29/2014] [Indexed: 12/21/2022]
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240
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Uehara Y, Saku K. High-density lipoprotein and atherosclerosis: Roles of lipid transporters. World J Cardiol 2014; 6:1049-1059. [PMID: 25349649 PMCID: PMC4209431 DOI: 10.4330/wjc.v6.i10.1049] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 02/10/2014] [Accepted: 08/31/2014] [Indexed: 02/06/2023] Open
Abstract
Various previous studies have found a negative correlation between the risk of cardiovascular events and serum high-density lipoprotein (HDL) cholesterol levels. The reverse cholesterol transport, a pathway of cholesterol from peripheral tissue to liver which has several potent antiatherogenic properties. For instance, the particles of HDL mediate to transport cholesterol from cells in arterial tissues, particularly from atherosclerotic plaques, to the liver. Both ATP-binding cassette transporters (ABC) A1 and ABCG1 are membrane cholesterol transporters and have been implicated in mediating cholesterol effluxes from cells in the presence of HDL and apolipoprotein A-I, a major protein constituent of HDL. Previous studies demonstrated that ABCA1 and ABCG1 or the interaction between ABCA1 and ABCG1 exerted antiatherosclerotic effects. As a therapeutic approach for increasing HDL cholesterol levels, much focus has been placed on increasing HDL cholesterol levels as well as enhancing HDL biochemical functions. HDL therapies that use injections of reconstituted HDL, apoA-I mimetics, or full-length apoA-I have shown dramatic effectiveness. In particular, a novel apoA-I mimetic peptide, Fukuoka University ApoA-I Mimetic Peptide, effectively removes cholesterol via specific ABCA1 and other transporters, such as ABCG1, and has an antiatherosclerotic effect by enhancing the biological functions of HDL without changing circulating HDL cholesterol levels. Thus, HDL-targeting therapy has significant atheroprotective potential, as it uses lipid transporter-targeting agents, and may prove to be a therapeutic tool for atherosclerotic cardiovascular diseases.
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241
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Sano O, Ito S, Kato R, Shimizu Y, Kobayashi A, Kimura Y, Kioka N, Hanada K, Ueda K, Matsuo M. ABCA1, ABCG1, and ABCG4 are distributed to distinct membrane meso-domains and disturb detergent-resistant domains on the plasma membrane. PLoS One 2014; 9:e109886. [PMID: 25302608 PMCID: PMC4193829 DOI: 10.1371/journal.pone.0109886] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Accepted: 09/12/2014] [Indexed: 11/19/2022] Open
Abstract
ATP-binding cassette A1 (ABCA1), ABCG1, and ABCG4 are lipid transporters that mediate the efflux of cholesterol from cells. To analyze the characteristics of these lipid transporters, we examined and compared their distributions and lipid efflux activity on the plasma membrane. The efflux of cholesterol mediated by ABCA1 and ABCG1, but not ABCG4, was affected by a reduction of cellular sphingomyelin levels. Detergent solubility and gradient density ultracentrifugation assays indicated that ABCA1, ABCG1, and ABCG4 were distributed to domains that were solubilized by Triton X-100 and Brij 96, resistant to Triton X-100 and Brij 96, and solubilized by Triton X-100 but resistant to Brij 96, respectively. Furthermore, ABCG1, but not ABCG4, was colocalized with flotillin-1 on the plasma membrane. The amounts of cholesterol extracted by methyl-β-cyclodextrin were increased by ABCA1, ABCG1, or ABCG4, suggesting that cholesterol in non-raft domains was increased. Furthermore, ABCG1 and ABCG4 disturbed the localization of caveolin-1 to the detergent-resistant domains and the binding of cholera toxin subunit B to the plasma membrane. These results suggest that ABCA1, ABCG1, and ABCG4 are localized to distinct membrane meso-domains and disturb the meso-domain structures by reorganizing lipids on the plasma membrane; collectively, these observations may explain the different substrate profiles and lipid efflux roles of these transporters.
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Affiliation(s)
- Osamu Sano
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Shiho Ito
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Reiko Kato
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Yuji Shimizu
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Aya Kobayashi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Yasuhisa Kimura
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Noriyuki Kioka
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Kentaro Hanada
- Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kazumitsu Ueda
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Sakyo, Kyoto, Japan
| | - Michinori Matsuo
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
- Department of Food and Nutrition, Faculty of Home Economics, Kyoto Women’s University, Kyoto, Japan
- * E-mail:
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242
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Tran-Dinh A, Diallo D, Delbosc S, Varela-Perez LM, Dang QB, Lapergue B, Burillo E, Michel JB, Levoye A, Martin-Ventura JL, Meilhac O. HDL and endothelial protection. Br J Pharmacol 2014; 169:493-511. [PMID: 23488589 DOI: 10.1111/bph.12174] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 02/07/2013] [Accepted: 02/24/2013] [Indexed: 12/23/2022] Open
Abstract
High-density lipoproteins (HDLs) represent a family of particles characterized by the presence of apolipoprotein A-I (apoA-I) and by their ability to transport cholesterol from peripheral tissues back to the liver. In addition to this function, HDLs display pleiotropic effects including antioxidant, anti-apoptotic, anti-inflammatory, anti-thrombotic or anti-proteolytic properties that account for their protective action on endothelial cells. Vasodilatation via production of nitric oxide is also a hallmark of HDL action on endothelial cells. Endothelial cells express receptors for apoA-I and HDLs that mediate intracellular signalling and potentially participate in the internalization of these particles. In this review, we will detail the different effects of HDLs on the endothelium in normal and pathological conditions with a particular focus on the potential use of HDL therapy to restore endothelial function and integrity.
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243
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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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244
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Common variants near ABCA1 and in PMM2 are associated with primary open-angle glaucoma. Nat Genet 2014; 46:1115-9. [PMID: 25173107 DOI: 10.1038/ng.3078] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 08/04/2014] [Indexed: 01/18/2023]
Abstract
We performed a genome-wide association study for primary open-angle glaucoma (POAG) in 1,007 cases with high-pressure glaucoma (HPG) and 1,009 controls from southern China. We observed genome-wide significant association at multiple SNPs near ABCA1 at 9q31.1 (rs2487032; P = 1.66 × 10(-8)) and suggestive evidence of association in PMM2 at 16p13.2 (rs3785176; P = 3.18 × 10(-6)). We replicated these findings in a set of 525 HPG cases and 912 controls from Singapore and a further set of 1,374 POAG cases and 4,053 controls from China. We observed genome-wide significant association with more than one SNP at the two loci (P = 2.79 × 10(-19) for rs2487032 representing ABCA1 and P = 5.77 × 10(-10) for rs3785176 representing PMM2). Both ABCA1 and PMM2 are expressed in the trabecular meshwork, optic nerve and other ocular tissues. In addition, ABCA1 is highly expressed in the ganglion cell layer of the retina, a finding consistent with it having a role in the development of glaucoma.
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245
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Lipids in the nervous system: from biochemistry and molecular biology to patho-physiology. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:51-60. [PMID: 25150974 DOI: 10.1016/j.bbalip.2014.08.011] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/08/2014] [Accepted: 08/12/2014] [Indexed: 12/16/2022]
Abstract
Lipids in the nervous system accomplish a great number of key functions, from synaptogenesis to impulse conduction, and more. Most of the lipids of the nervous system are localized in myelin sheaths. It has long been known that myelin structure and brain homeostasis rely on specific lipid-protein interactions and on specific cell-to-cell signaling. In more recent years, the growing advances in large-scale technologies and genetically modified animal models have provided valuable insights into the role of lipids in the nervous system. Key findings recently emerged in these areas are here summarized. In addition, we briefly discuss how this new knowledge can open novel approaches for the treatment of diseases associated with alteration of lipid metabolism/homeostasis in the nervous system. This article is part of a Special Issue entitled Linking transcription to physiology in lipidomics.
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246
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ApoA-I/HDL Generation and Intracellular Cholesterol Transport through Cytosolic Lipid-Protein Particles in Astrocytes. J Lipids 2014; 2014:530720. [PMID: 25197575 PMCID: PMC4146353 DOI: 10.1155/2014/530720] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 06/24/2014] [Indexed: 01/24/2023] Open
Abstract
Exogenous apolipoprotein A-I (apoA-I) associates with ATP-binding cassette transporter A1 (ABCA1) on the cell surface of astrocytes like various peripheral cells and enhances the translocation of newly synthesized cholesterol from the endoplasmic reticulum/Golgi apparatus (ER/Golgi) to the cytosol. The cholesterol translocated to the cytosol is incorporated to cytosolic lipid-protein particles (CLPP) together with phospholipids and proteins such as sphingomyelin, phosphatidylcholine, caveolin-1, protein kinase Cα (PK-Cα), and cyclophilin A. The CLPP are high density lipoproteins- (HDL-)like cytosolic lipid-protein complex with densities of 1.09–1.16 g/mL and diameters of 17-18 nm. The association of exogenous apoA-I with cellular ABCA1 induces tyrosine phosphorylation, activation, and translocation to the CLPP of ABCA1-associated phospholipase Cγ (PL-Cγ) in rat astrocytes. Furthermore, PK-Cα is translocated and activated to/in the CLPP through theproduction of diacylglyceride in the CLPP. ApoA-I enhances both the association of CLPP with microtubules and the phosphorylation of α-tubulin as a component of microtubules. The CLPP are dissociated from microtubules after α-tubulin in microtubules is phosphorylated by the CLPP-associated PK-Cα. The association and dissociation between CLPP and microtubules may participate in the intracellular transport of cholesterol to the plasma membrane.
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247
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Nesan D, Ng DS. Revising the high-density lipoprotein targeting strategies - insights from human and preclinical studies. Crit Rev Clin Lab Sci 2014; 51:321-31. [PMID: 25115413 DOI: 10.3109/10408363.2014.937523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In recent years, the high-density lipoprotein (HDL) hypothesis has been challenged. Several completed randomized clinical trials continue to fall short in demonstrating HDL, or at least HDL-cholesterol (HDL-C) levels, as being a consistent target in the prevention of cardiovascular diseases. However, population studies and findings in lipid modifying trials continue to strongly support HDL-C as a superb risk predictor. It is increasingly evident that the complexity of HDL metabolism confounds the use of HDL-C concentration as a unified target. However, important insights continue to emerge from the post hoc analyses of recently completed (i) fibrate-based FIELD and ACCORD trials, including the unexpected beneficial effect of fibrates in microvascular diseases, (ii) the niacin-based AIM-HIGH and HPS2-THRIVE studies, (iii) recombinant HDL-based as well as (iv) the completed CETP inhibitor-based trials. These together with on-going mechanistic studies on novel pathways, which include the unique roles of microRNAs, post-translational remodeling of HDL and novel pathways related to HDL modulators will provide valuable insights to guide how best to refocus and redesign the conceptual framework for selecting HDL-based targets.
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Affiliation(s)
- Dinushan Nesan
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital , Toronto, Ontario , Canada
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248
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Abstract
PURPOSE OF REVIEW The objective of this review article is to summarize the recent findings about the importance of microRNAs (miRNAs) in regulating lipoprotein metabolism. We highlight the recent findings that uncover the importance of miRNAs in controlling plasma LDL-cholesterol (LDL-C) levels. RECENT FINDINGS In 2013, several studies reported a number of miRNAs that regulate plasma LDL-C levels, including miR-30c. In this review article, we discuss those miRNAs that modulate LDL-C levels and lipoprotein secretion. We also discuss the numerous studies that demonstrate the critical role of miRNAs in governing the many facets of HDL metabolism, such as the ATP transporters, ABCA1, and ABCG1, and the scavenger receptor, SRB1. SUMMARY The understanding of how these miRNAs modulate lipoprotein metabolism promises to reveal new therapeutic targets to treat dyslipidemias and related cardiovascular disorders.
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Affiliation(s)
- Leigh Goedeke
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, Connecticut, USA
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Section of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
- Departments of Medicine, Leon H. Charney Division of Cardiology, New York University School of Medicine, New York, New York, USA
| | - Juan F. Aranda
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, Connecticut, USA
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Section of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Carlos Fernández-Hernando
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, Connecticut, USA
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Section of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
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249
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Yang X, Yang J, Li L, Sun L, Yi X, Han X, Si W, Yan R, Chen Z, Xie G, Li W, Shang Y, Liang J. PAAT, a novel ATPase and trans-regulator of mitochondrial ABC transporters, is critically involved in the maintenance of mitochondrial homeostasis. FASEB J 2014; 28:4821-34. [PMID: 25063848 DOI: 10.1096/fj.14-254045] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
ATP-binding cassette (ABC) transporters are implicated in a diverse range of physiological and pathophysiological processes, such as cholesterol and lipid transportation and multidrug resistance. Despite the considerable efforts made in understanding of the cellular function of ABC proteins, the regulation mechanism of this type of protein is still poorly defined. Here we report the identification and functional characterization of a novel ATPase protein, protein associated with ABC transporters (PAAT), in humans. PAAT contains a nucleotide-binding domain (NBD)-like domain and a signal for intramitochondrial sorting. We showed that PAAT is localized in both the cytoplasm and the mitochondria and has an intrinsic ATPase activity. PAAT physically interacts with the 3 known mitochondrial inner membrane ABC proteins, ABCB7, ABCB8, and ABCB10, but not ABCB1, ABCB6, or ABCG2, and functionally regulates the transport of ferric nutrients and heme biosynthesis. Significantly, PAAT deficiency promotes cell death, reduces mitochondrial potential, and sensitizes mitochondria to oxidative stress-induced DNA damages. Our experiments revealed that PAAT is a novel ATPase and a trans-regulator of mitochondrial ABC transporters that plays an important role in the maintenance of mitochondrial homeostasis and cell survival.
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Affiliation(s)
- Xiaohan Yang
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China; and
| | - Jianguo Yang
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China; and
| | - Lei Li
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China; and
| | - Luyang Sun
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China; and
| | - Xia Yi
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China; and
| | - Xiao Han
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China; and
| | - Wenzhe Si
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China; and Tianjin Key Laboratory of Medical Epigenetics, Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin, China
| | - Ruorong Yan
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China; and
| | - Zhe Chen
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China; and
| | - Guojia Xie
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China; and
| | - Wanjin Li
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China; and
| | - Yongfeng Shang
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China; and Tianjin Key Laboratory of Medical Epigenetics, Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin, China
| | - Jing Liang
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China; and
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250
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Rinninger F, Heine M, Singaraja R, Hayden M, Brundert M, Ramakrishnan R, Heeren J. High density lipoprotein metabolism in low density lipoprotein receptor-deficient mice. J Lipid Res 2014; 55:1914-24. [PMID: 24954421 DOI: 10.1194/jlr.m048819] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The LDL receptor (LDLR) and scavenger receptor class B type I (SR-BI) play physiological roles in LDL and HDL metabolism in vivo. In this study, we explored HDL metabolism in LDLR-deficient mice in comparison with WT littermates. Murine HDL was radiolabeled in the protein ((125)I) and in the cholesteryl ester (CE) moiety ([(3)H]). The metabolism of (125)I-/[(3)H]HDL was investigated in plasma and in tissues of mice and in murine hepatocytes. In WT mice, liver and adrenals selectively take up HDL-associated CE ([(3)H]). In contrast, in LDLR(-/-) mice, selective HDL CE uptake is significantly reduced in liver and adrenals. In hepatocytes isolated from LDLR(-/-) mice, selective HDL CE uptake is substantially diminished compared with WT liver cells. Hepatic and adrenal protein expression of lipoprotein receptors SR-BI, cluster of differentiation 36 (CD36), and LDL receptor-related protein 1 (LRP1) was analyzed by immunoblots. The respective protein levels were identical both in hepatic and adrenal membranes prepared from WT or from LDLR(-/-) mice. In summary, an LDLR deficiency substantially decreases selective HDL CE uptake by liver and adrenals. This decrease is independent from regulation of receptor proteins like SR-BI, CD36, and LRP1. Thus, LDLR expression has a substantial impact on both HDL and LDL metabolism in mice.
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Affiliation(s)
- Franz Rinninger
- Department of Medicine, University Hospital Hamburg Eppendorf, 20246 Hamburg, Germany
| | - Markus Heine
- Department of Biochemistry and Molecular Cell Biology, University Hospital Hamburg Eppendorf, 20246 Hamburg, Germany
| | - Roshni Singaraja
- Translational Laboratories in Genetic Medicine, Agency for Science, Technology and Research National University of Singapore, Singapore 117609 Department of Medicine, National University of Singapore, Singapore 117609
| | - Michael Hayden
- Centre for Molecular Medicine and Therapeutics and Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - May Brundert
- Department of Medicine, University Hospital Hamburg Eppendorf, 20246 Hamburg, Germany
| | - Rajasekhar Ramakrishnan
- Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, NY 10032
| | - Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Hospital Hamburg Eppendorf, 20246 Hamburg, Germany
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