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Lin H, Mensch J, Haschke M, Jäger K, Köttgen B, Dernedde J, Orsó E, Walter M. Establishment and Characterization of hTERT Immortalized Hutchinson–Gilford Progeria Fibroblast Cell Lines. Cells 2022; 11:cells11182784. [PMID: 36139359 PMCID: PMC9497314 DOI: 10.3390/cells11182784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/29/2022] [Accepted: 09/02/2022] [Indexed: 11/22/2022] Open
Abstract
Hutchinson–Gilford progeria syndrome (HGPS) is a rare premature aging syndrome caused by a dominant mutation in the LMNA gene. Previous research has shown that the ectopic expression of the catalytic subunit of telomerase (hTERT) can elongate the telomeres of the patients’ fibroblasts. Here, we established five immortalized HGP fibroblast cell lines using retroviral infection with the catalytic subunit of hTERT. Immortalization enhanced the proliferative life span by at least 50 population doublings (PDs). The number of cells with typical senescence signs was reduced by 63 + 17%. Furthermore, the growth increase and phenotype improvement occurred with a lag phase of 50–100 days and was not dependent on the degree of telomere elongation. The initial telomeric stabilization after hTERT infection and relatively low amounts of hTERT mRNA were sufficient for the phenotype improvement but the retroviral infection procedure was associated with transient cell stress. Our data have implications for therapeutic strategies in HGP and other premature aging syndromes.
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Affiliation(s)
- Haihuan Lin
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, 13353 Berlin, Germany
| | - Juliane Mensch
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, 13353 Berlin, Germany
- Institute of Clinical Chemistry and Laboratory Medicine, Rostock University Medical Center, 18057 Rostock, Germany
| | - Maria Haschke
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, 13353 Berlin, Germany
- Institute of Clinical Chemistry and Laboratory Medicine, Rostock University Medical Center, 18057 Rostock, Germany
| | - Kathrin Jäger
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, 13353 Berlin, Germany
- Institute of Clinical Chemistry and Laboratory Medicine, Rostock University Medical Center, 18057 Rostock, Germany
| | - Brigitte Köttgen
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, 13353 Berlin, Germany
| | - Jens Dernedde
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, 13353 Berlin, Germany
| | - Evelyn Orsó
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, 93053 Regensburg, Germany
| | - Michael Walter
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, 13353 Berlin, Germany
- Institute of Clinical Chemistry and Laboratory Medicine, Rostock University Medical Center, 18057 Rostock, Germany
- Correspondence:
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Kumar A, Zhong Y, Albrecht A, Sang PB, Maples A, Liu Z, Vinayachandran V, Reja R, Lee CF, Kumar A, Chen J, Xiao J, Park B, Shen J, Liu B, Person MD, Trybus KM, Zhang KYJ, Pugh BF, Kamm KE, Milewicz DM, Shen X, Kapoor P. Actin R256 Mono-methylation Is a Conserved Post-translational Modification Involved in Transcription. Cell Rep 2021; 32:108172. [PMID: 32997990 PMCID: PMC8860185 DOI: 10.1016/j.celrep.2020.108172] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 07/11/2020] [Accepted: 08/27/2020] [Indexed: 12/19/2022] Open
Abstract
Nuclear actin has been elusive due to the lack of knowledge about molecular mechanisms. From actin-containing chromatin remodeling complexes, we discovered an arginine mono-methylation mark on an evolutionarily conserved R256 residue of actin (R256me1). Actin R256 mutations in yeast affect nuclear functions and cause diseases in human. Interestingly, we show that an antibody specific for actin R256me1 preferentially stains nuclear actin over cytoplasmic actin in yeast, mouse, and human cells. We also show that actin R256me1 is regulated by protein arginine methyl transferase-5 (PRMT5) in HEK293 cells. A genome-wide survey of actin R256me1 mark provides a landscape for nuclear actin correlated with transcription. Further, gene expression and protein interaction studies uncover extensive correlations between actin R256me1 and active transcription. The discovery of actin R256me1 mark suggests a fundamental mechanism to distinguish nuclear actin from cytoplasmic actin through post-translational modification (PTM) and potentially implicates an actin PTM mark in transcription and human diseases. Nuclear actin and actin PTMs are poorly understood. Kumar et al. discover a system of actin PTMs similar to histone PTMs, including a conserved mark on nuclear actin (R256me1) with potential implications for transcription and human diseases.
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Affiliation(s)
- Ashok Kumar
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, TX 75708, USA
| | - Yuan Zhong
- Department of Epigenetics and Molecular Carcinogenesis, Science Park Research Division, The University of Texas M.D. Anderson Cancer Center, Smithville, TX 78957, USA
| | - Amelie Albrecht
- Department of Epigenetics and Molecular Carcinogenesis, Science Park Research Division, The University of Texas M.D. Anderson Cancer Center, Smithville, TX 78957, USA; The University of Texas M.D. Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Pau Biak Sang
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, TX 75708, USA
| | - Adrian Maples
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, TX 75708, USA
| | - Zhenan Liu
- Department of Physiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Vinesh Vinayachandran
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Rohit Reja
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Chia-Fang Lee
- ICMB Proteomics Facility, The University of Texas at Austin, Austin, TX 78712, USA
| | - Ashutosh Kumar
- Laboratory for Structural Bioinformatics, Center for Biosystems Dynamics Research, RIKEN, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
| | - Jiyuan Chen
- Department of Internal Medicine, University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX, USA
| | - Jing Xiao
- Department of Epigenetics and Molecular Carcinogenesis, Science Park Research Division, The University of Texas M.D. Anderson Cancer Center, Smithville, TX 78957, USA
| | - Bongsoo Park
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Jianjun Shen
- Department of Epigenetics and Molecular Carcinogenesis, Science Park Research Division, The University of Texas M.D. Anderson Cancer Center, Smithville, TX 78957, USA
| | - Bin Liu
- Department of Epigenetics and Molecular Carcinogenesis, Science Park Research Division, The University of Texas M.D. Anderson Cancer Center, Smithville, TX 78957, USA
| | - Maria D Person
- ICMB Proteomics Facility, The University of Texas at Austin, Austin, TX 78712, USA
| | - Kathleen M Trybus
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405, USA
| | - Kam Y J Zhang
- Laboratory for Structural Bioinformatics, Center for Biosystems Dynamics Research, RIKEN, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
| | - B Franklin Pugh
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Kristine E Kamm
- Department of Physiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Dianna M Milewicz
- Department of Internal Medicine, University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX, USA
| | - Xuetong Shen
- Department of Epigenetics and Molecular Carcinogenesis, Science Park Research Division, The University of Texas M.D. Anderson Cancer Center, Smithville, TX 78957, USA.
| | - Prabodh Kapoor
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, TX 75708, USA.
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Telomere attrition and dysfunction: a potential trigger of the progeroid phenotype in nijmegen breakage syndrome. Aging (Albany NY) 2020; 12:12342-12375. [PMID: 32564008 PMCID: PMC7343506 DOI: 10.18632/aging.103453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 05/27/2020] [Indexed: 12/17/2022]
Abstract
Background: Nibrin, as part of the NBN/MRE11/RAD50 complex, is mutated in Nijmegen breakage syndrome (NBS), which leads to impaired DNA damage response and lymphoid malignancy. Results: Telomere length (TL) was markedly reduced in homozygous patients (and comparably so in all chromosomes) by ~40% (qPCR) and was slightly reduced in NBS heterozygotes older than 30 years (~25% in qPCR), in accordance with the respective cancer rates. Humanized cancer-free NBS mice had normal TL. Telomere elongation was inducible by telomerase and/or alternative telomere lengthening but was associated with abnormal expression of telomeric genes involved in aging and/or cell growth. Lymphoblastoid cells from NBS patients with long survival times (>12 years) displayed the shortest telomeres and low caspase 7 activity. Conclusions: NBS is a secondary telomeropathy. The two-edged sword of telomere attrition enhances the cancer-prone situation in NBS but can also lead to a relatively stable cellular phenotype in tumor survivors. Results suggest a modular model for progeroid syndromes with abnormal expression of telomeric genes as a molecular basis. Methods: We studied TL and function in 38 homozygous individuals, 27 heterozygotes, one homozygous fetus, six NBS lymphoblastoid cell lines, and humanized NBS mice, all with the same founder NBN mutation: c.657_661del5.
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Vascular disease-causing mutation, smooth muscle α-actin R258C, dominantly suppresses functions of α-actin in human patient fibroblasts. Proc Natl Acad Sci U S A 2017; 114:E5569-E5578. [PMID: 28652363 DOI: 10.1073/pnas.1703506114] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The most common genetic alterations for familial thoracic aortic aneurysms and dissections (TAAD) are missense mutations in vascular smooth muscle (SM) α-actin encoded by ACTA2 We focus here on ACTA2-R258C, a recurrent mutation associated with early onset of TAAD and occlusive moyamoya-like cerebrovascular disease. Recent biochemical results with SM α-actin-R258C predicted that this variant will compromise multiple actin-dependent functions in intact cells and tissues, but a model system to measure R258C-induced effects was lacking. We describe the development of an approach to interrogate functional consequences of actin mutations in affected patient-derived cells. Primary dermal fibroblasts from R258C patients exhibited increased proliferative capacity compared with controls, consistent with inhibition of growth suppression attributed to SM α-actin. Telomerase-immortalized lines of control and R258C human dermal fibroblasts were established and SM α-actin expression induced with adenovirus encoding myocardin-related transcription factor A, a potent coactivator of ACTA2 Two-dimensional Western blotting confirmed induction of both wild-type and mutant SM α-actin in heterozygous ACTA2-R258C cells. Expression of mutant SM α-actin in heterozygous ACTA2-R258C fibroblasts abrogated the significant effects of SM α-actin induction on formation of stress fibers and focal adhesions, filamentous to soluble actin ratio, matrix contraction, and cell migration. These results demonstrate that R258C dominantly disrupts cytoskeletal functions attributed to SM α-actin in fibroblasts and are consistent with deficiencies in multiple cytoskeletal functions. Thus, cellular defects due to this ACTA2 mutation in both aortic smooth muscle cells and adventitial fibroblasts may contribute to development of TAAD and proliferative occlusive vascular disease.
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Jäger K, Walter M. Therapeutic Targeting of Telomerase. Genes (Basel) 2016; 7:genes7070039. [PMID: 27455328 PMCID: PMC4962009 DOI: 10.3390/genes7070039] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 06/16/2016] [Accepted: 06/24/2016] [Indexed: 12/20/2022] Open
Abstract
Telomere length and cell function can be preserved by the human reverse transcriptase telomerase (hTERT), which synthesizes the new telomeric DNA from a RNA template, but is normally restricted to cells needing a high proliferative capacity, such as stem cells. Consequently, telomerase-based therapies to elongate short telomeres are developed, some of which have successfully reached the stage I in clinical trials. Telomerase is also permissive for tumorigenesis and 90% of all malignant tumors use telomerase to obtain immortality. Thus, reversal of telomerase upregulation in tumor cells is a potential strategy to treat cancer. Natural and small-molecule telomerase inhibitors, immunotherapeutic approaches, oligonucleotide inhibitors, and telomerase-directed gene therapy are useful treatment strategies. Telomerase is more widely expressed than any other tumor marker. The low expression in normal tissues, together with the longer telomeres in normal stem cells versus cancer cells, provides some degree of specificity with low risk of toxicity. However, long term telomerase inhibition may elicit negative effects in highly-proliferative cells which need telomerase for survival, and it may interfere with telomere-independent physiological functions. Moreover, only a few hTERT molecules are required to overcome senescence in cancer cells, and telomerase inhibition requires proliferating cells over a sufficient number of population doublings to induce tumor suppressive senescence. These limitations may explain the moderate success rates in many clinical studies. Despite extensive studies, only one vaccine and one telomerase antagonist are routinely used in clinical work. For complete eradication of all subpopulations of cancer cells a simultaneous targeting of several mechanisms will likely be needed. Possible technical improvements have been proposed including the development of more specific inhibitors, methods to increase the efficacy of vaccination methods, and personalized approaches. Telomerase activation and cell rejuvenation is successfully used in regenerative medicine for tissue engineering and reconstructive surgery. However, there are also a number of pitfalls in the treatment with telomerase activating procedures for the whole organism and for longer periods of time. Extended cell lifespan may accumulate rare genetic and epigenetic aberrations that can contribute to malignant transformation. Therefore, novel vector systems have been developed for a 'mild' integration of telomerase into the host genome and loss of the vector in rapidly-proliferating cells. It is currently unclear if this technique can also be used in human beings to treat chronic diseases, such as atherosclerosis.
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Affiliation(s)
- Kathrin Jäger
- Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, Berlin 13353, Germany.
| | - Michael Walter
- Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, Berlin 13353, Germany.
- Labor Berlin-Charité Vivantes Services GmbH, Sylter Str. 2, Berlin 13353, Germany.
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Kannenberg F, Gorzelniak K, Jäger K, Fobker M, Rust S, Repa J, Roth M, Björkhem I, Walter M. Characterization of cholesterol homeostasis in telomerase-immortalized Tangier disease fibroblasts reveals marked phenotype variability. J Biol Chem 2013; 288:36936-47. [PMID: 24196952 DOI: 10.1074/jbc.m113.500256] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We compared the consequences of an ABCA1 mutation that produced an apparent lack of atherosclerosis (Tangier family 1, N935S) with an ABCA1 mutation with functional ABCA1 knockout that was associated with severe atherosclerosis (Tangier family 2, Leu(548):Leu(575)-End), using primary and telomerase-immortalized fibroblasts. Telomerase-immortalized Tangier fibroblasts of family 1 (TT1) showed 30% residual cholesterol efflux capacity in response to apolipoprotein A-I, whereas telomerase-immortalized Tangier fibroblasts of family 2 (TT2) showed only 20%. However, there were a number of secondary differences that were often stronger and may help to explain the more rapid development of atherosclerosis in family 2. First, the total cellular cholesterol content increase was 2-3-fold and 3-5-fold in TT1 and TT2 cells, respectively. The corresponding increase in esterified cholesterol concentration was 10- and 40-fold, respectively. Second, 24-, 25-, and 27-hydroxycholesterol concentrations were moderately increased in TT1 cells, but were increased as much as 200-fold in TT2 cells. Third, cholesterol biosynthesis was moderately decreased in TT1 cells, but was markedly decreased in TT2 cells. Fourth, potentially atheroprotective LXR-dependent SREBP1c signaling was normal in TT1, but was rather suppressed in TT2 cells. Cultivated primary Tangier fibroblasts were characterized by premature aging in culture and were associated with less obvious biochemical differences. In summary, these results may help to understand the differential atherosclerotic susceptibility in Tangier disease and further demonstrate the usefulness of telomerase-immortalized cells in studying this cellular phenotype. The data support the contention that side chain-oxidized oxysterols are strong suppressors of cholesterol biosynthesis under specific pathological conditions in humans.
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Affiliation(s)
- Frank Kannenberg
- From the Center for Laboratory Medicine, University of Münster, 48149 Münster, Germany
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Chen J, Zhang X, Kusumo H, Costa LG, Guizzetti M. Cholesterol efflux is differentially regulated in neurons and astrocytes: implications for brain cholesterol homeostasis. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1831:263-75. [PMID: 23010475 DOI: 10.1016/j.bbalip.2012.09.007] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 09/05/2012] [Accepted: 09/14/2012] [Indexed: 11/15/2022]
Abstract
Disruption of cholesterol homeostasis in the central nervous system (CNS) has been associated with neurological, neurodegenerative, and neurodevelopmental disorders. The CNS is a closed system with regard to cholesterol homeostasis, as cholesterol-delivering lipoproteins from the periphery cannot pass the blood-brain-barrier and enter the brain. Different cell types in the brain have different functions in the regulation of cholesterol homeostasis, with astrocytes producing and releasing apolipoprotein E and lipoproteins, and neurons metabolizing cholesterol to 24(S)-hydroxycholesterol. We present evidence that astrocytes and neurons adopt different mechanisms also in regulating cholesterol efflux. We found that in astrocytes cholesterol efflux is induced by both lipid-free apolipoproteins and lipoproteins, while cholesterol removal from neurons is triggered only by lipoproteins. The main pathway by which apolipoproteins induce cholesterol efflux is through ABCA1. By upregulating ABCA1 levels and by inhibiting its activity and silencing its expression, we show that ABCA1 is involved in cholesterol efflux from astrocytes but not from neurons. Furthermore, our results suggest that ABCG1 is involved in cholesterol efflux to apolipoproteins and lipoproteins from astrocytes but not from neurons, while ABCG4, whose expression is much higher in neurons than astrocytes, is involved in cholesterol efflux from neurons but not astrocytes. These results indicate that different mechanisms regulate cholesterol efflux from neurons and astrocytes, reflecting the different roles that these cell types play in brain cholesterol homeostasis. These results are important in understanding cellular targets of therapeutic drugs under development for the treatments of conditions associated with altered cholesterol homeostasis in the CNS.
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Affiliation(s)
- Jing Chen
- Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt way NE, Seattle, WA 98105, USA
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Subtoxicdose of Chlorpyrifos Down Regulates ABCA1 Expression and Accelerates Formation of Atherosclerosis Induced by The High Fat Diet in New Zealand Rabbits*. PROG BIOCHEM BIOPHYS 2011. [DOI: 10.3724/sp.j.1206.2010.00046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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9
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Okuhira K, Fitzgerald ML, Tamehiro N, Ohoka N, Suzuki K, Sawada JI, Naito M, Nishimaki-Mogami T. Binding of PDZ-RhoGEF to ATP-binding cassette transporter A1 (ABCA1) induces cholesterol efflux through RhoA activation and prevention of transporter degradation. J Biol Chem 2010; 285:16369-77. [PMID: 20348106 DOI: 10.1074/jbc.m109.061424] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
ATP-binding cassette transporter A1 (ABCA1)-mediated lipid efflux to apolipoprotein A1 (apoA-I) initiates the biogenesis of high density lipoprotein. Here we show that the Rho guanine nucleotide exchange factors PDZ-RhoGEF and LARG bind to the C terminus of ABCA1 by a PDZ-PDZ interaction and prevent ABCA1 protein degradation by activating RhoA. ABCA1 is a protein with a short half-life, and apoA-I stabilizes ABCA1 protein; however, depletion of PDZ-RhoGEF/LARG by RNA interference suppressed the apoA-I stabilization of ABCA1 protein in human primary fibroblasts. Exogenous PDZ-RhoGEF expression activated RhoA and increased ABCA1 protein levels and cholesterol efflux activity. Likewise, forced expression of a constitutively active RhoA mutant significantly increased ABCA1 protein levels, whereas a dominant negative RhoA mutant decreased them. The constitutively active RhoA retarded ABCA1 degradation, thus accounting for its ability to increase ABCA1 protein. Moreover, stimulation with apoA-I transiently activated RhoA, and the pharmacological inhibition of RhoA or the dominant negative RhoA blocked the ability of apoA-I to stabilize ABCA1. Finally, depletion of RhoA or RhoGEFs/RhoA reduces the cholesterol efflux when transcriptional regulation via PPARgamma is eliminated. Taken together, our results have identified a novel physical and functional interaction between ABCA1 and PDZ-RhoGEF/LARG, which activates RhoA, resulting in ABCA1 stabilization and cholesterol efflux activity.
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Affiliation(s)
- Keiichiro Okuhira
- National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8511, Japan
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Liu JP, Tang Y, Zhou S, Toh BH, McLean C, Li H. Cholesterol involvement in the pathogenesis of neurodegenerative diseases. Mol Cell Neurosci 2010; 43:33-42. [DOI: 10.1016/j.mcn.2009.07.013] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 07/29/2009] [Accepted: 07/29/2009] [Indexed: 11/27/2022] Open
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Walter M. Interrelationships Among HDL Metabolism, Aging, and Atherosclerosis. Arterioscler Thromb Vasc Biol 2009; 29:1244-50. [DOI: 10.1161/atvbaha.108.181438] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Michael Walter
- From the Charité-Universitätsmedizin Berlin, Department of Laboratory Medicine and Pathobiochemistry, Germany and the Unfallkranken haus Berlin, Germany
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Matsuura F, Hirano KI, Ikegami C, Sandoval JC, Oku H, Yuasa-Kawase M, Tsubakio-Yamamoto K, Koseki M, Masuda D, Tsujii KI, Ishigami M, Nishida M, Shimomura I, Hori M, Yamashita S. Senescent phenotypes of skin fibroblasts from patients with Tangier disease. Biochem Biophys Res Commun 2007; 357:493-8. [PMID: 17434146 DOI: 10.1016/j.bbrc.2007.03.172] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Accepted: 03/27/2007] [Indexed: 11/19/2022]
Abstract
Tangier disease (TD) is characterized by a deficiency of high density lipoprotein (HDL) in plasma and patients with TD have an increased risk for coronary artery disease (CAD). Recently, we reported that fibroblasts from TD exhibited large and flattened morphology, which is often observed in senescent cells. On the other hand, data have accumulated to show the relationship between cellular senescence and development of atherosclerotic CAD. The aim of the present study was to investigate whether TD fibroblasts exhibited cellular senescence. The proliferation of TD fibroblasts was gradually decreased at population doubling level (PDL) approximately 10 compared with control cells. TD cells practically ceased proliferation at PDL approximately 30. DNA synthesis was markedly decreased in TD fibroblasts. TD cells exhibited a higher positive rate for senescence-associated beta-galactosidase (SA-beta-gal), which is one of the biomarkers of cellular senescence in vitro. These data showed that TD cells reached cellular senescence at an earlier PDL compared with controls. Although, there was no difference in the telomere length of fibroblasts between TD and controls at the earlier passage (PDL 6), the telomere length of TD cells was shorter than that of controls at the late passage (PDL 25). Taken together, the current study demonstrates that the late-passaged TD fibroblasts showed senescent phenotype in vitro, which might be related to the increased cardiovascular manifestations in TD patients.
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Affiliation(s)
- Fumihiko Matsuura
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, 2-2, Yamadaoka, Suita, Osaka 565-0871, Japan.
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Nofer JR, Walter M, Assmann G. Current understanding of the role of high-density lipoproteins in atherosclerosis and senescence. Expert Rev Cardiovasc Ther 2006; 3:1071-86. [PMID: 16292998 DOI: 10.1586/14779072.3.6.1071] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Numerous epidemiologic and interventional studies revealed that high-density lipoprotein (HDL) is an important risk factor for coronary heart disease. There are several well documented HDL functions that may account for the antiatherogenic effects of this lipoprotein. The best recognized of these is the capacity of HDL to transport cholesterol from the periphery to the liver, and thereby prevent cholesterol deposition in the arterial wall. Further properties of HDL that may also be antiatherogenic include its potent anti oxidative and anti-inflammatory action. In addition, HDL seems to be involved in processes related to senescence at both the cellular and whole-organism level. Both protein components of HDL (such as apolipoprotein A-I) and its lipid components (such as, lysosphingolipids) appear to mediate the antiatherogenic and anti-aging effects of HDL. The purpose of this review is to summarize the novel functions of HDL that may protect from atherosclerosis and senescence.
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Affiliation(s)
- Jerzy-Roch Nofer
- Institut für Klinische Chemie und Laboratoriumsmedizin, Universitätsklinikum Münster, Albert Schweizer Str. 33 D-48129, Münster, Germany.
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Huang ZH, Fitzgerald ML, Mazzone T. Distinct Cellular Loci for the ABCA1-Dependent and ABCA1-Independent Lipid Efflux Mediated by Endogenous Apolipoprotein E Expression. Arterioscler Thromb Vasc Biol 2006; 26:157-62. [PMID: 16254198 DOI: 10.1161/01.atv.0000193627.12516.1d] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Macrophage expression of both apolipoprotein E (apoE) and ABCA1 have been shown to modulate lipid efflux from these cells and to play an important atheroprotective role in vivo. We evaluated the relationship between apoE and ABCA1 for regulating cellular sterol efflux. METHODS AND RESULTS ApoE-mediated, but ABCA1-independent, lipid efflux was demonstrated in 3 model systems. First, adenoviral-mediated expression of apoE in dermal fibroblasts isolated from ABCA1(-/-) mice significantly increased both sterol and phospholipid efflux. Second, expression of human apoE in a macrophage cell line increased sterol efflux, and this increment in efflux was not reduced by suppressing ABCA1 expression. Third, reduction of apoE expression using an apoE small interfering RNA significantly reduced sterol efflux from ABCA1(-/-) mouse peritoneal macrophages. ApoE-mediated, but ABCA1-independent, lipid efflux could be differentiated from lipid efflux that was dependent on the extracellular accumulation of secreted apoE, because exogenous cell-derived apoE stimulated efflux only from cells expressing ABCA1. Sterol efflux was usually highest in cells expressing both ABCA1 and apoE, likely representing a summation of the ABCA1-dependent and -independent pathways for apoE-mediated sterol efflux. CONCLUSIONS ABCA1 expression is required for apoE-mediated efflux when endogenously synthesized apoE accumulates extracellularly. Our results, however, establish the existence of an ABCA1-independent pathway for lipid efflux that requires the intracellular synthesis and/or transport of apoE.
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Affiliation(s)
- Zhi H Huang
- Department of Medicine, University of Illinois, Chicago, IL 60612, USA
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15
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Abstract
ATP binding cassette transporter A1 (ABCA1) mediates the cellular efflux of phospholipids and cholesterol to lipid-poor apolipoprotein A1 (apoA1) and plays a significant role in high density lipoprotein (HDL) metabolism. ABCA1's role in the causation of Tangier disease, characterized by absent HDL and premature atherosclerosis, has implicated this transporter and its regulators liver-X-receptoralpha (LXRalpha) and peroxisome proliferator activated receptorgamma (PPARgamma) as new candidates potentially influencing the progression of atherosclerosis. In addition to lipid regulation, these genes are involved in apoptosis and inflammation, processes thought to be central to atherosclerotic plaque progression. A Medline-based review of the literature was carried out. Tangier disease and human heterozygotes with ABCA1 mutations provide good evidence that ABCA1 is a major candidate influencing atherosclerosis. Animal and in vitro experiments suggest that ABCA1 not only mediates cholesterol and phospholipid efflux, but is also involved in the regulation of apoptosis and inflammation. The complex and beneficial interactions between apoA1 and ABCA1 seem to be pivotal for cholesterol efflux. The expression of the ABCA1 is tightly regulated. Furthermore the plaque microenvironment could potentially promote ABCA1 protein degradation thus compromising cholesterol efflux. PPAR-LXR-ABCA1 interactions are integral to cholesterol homeostasis and these nuclear receptors have proven anti-inflammatory and anti-matrix metalloproteinase activity. Therapeutic manipulation of the ABCA1 transporter is feasible using PPAR and LXR agonists. PPAR agonists like glitazones and ABCA1 protein stabilization could potentially modify the clinical progression of atherosclerotic lesions.
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Affiliation(s)
- S Soumian
- Department of Vascular Surgery, Faculty of Medicine, Imperial College, Charing Cross Hospital, London, UK.
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16
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Koldamova RP, Lefterov IM, Staufenbiel M, Wolfe D, Huang S, Glorioso JC, Walter M, Roth MG, Lazo JS. The liver X receptor ligand T0901317 decreases amyloid beta production in vitro and in a mouse model of Alzheimer's disease. J Biol Chem 2004; 280:4079-88. [PMID: 15557325 DOI: 10.1074/jbc.m411420200] [Citation(s) in RCA: 201] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recent studies indicate that oxysterols, which are ligands for the nuclear hormone liver X receptors (LXR), decrease amyloid beta (Abeta) secretion in vitro. The effect was attributed primarily to the ATP-binding cassette transporter A1 (ABCA1) transcriptionally up-regulated by ligand-activated LXRs. We now examined the effect of the synthetic LXR ligand T0901317, which can be used in vivo, on Abeta production in vitro and in APP23 transgenic mice. T0901317 applied to a variety of in vitro models, including immortalized fibroblasts from Tangier patients, and primary embryonic mouse neurons caused a concentration-dependent decrease in Abeta secretion, and this effect was increased by the addition of apolipoprotein A-I. The inhibition of Abeta production by T0901317 was cell-type specific, being more prominent in primary neurons than in non-neuronal cells. Tangier fibroblasts lacking a functional ABCA1 secreted more Abeta than control fibroblasts, thus demonstrating the role of ABCA1 in amyloid precursor protein (APP) processing and Abeta generation. T0901317 treatment of 11-week-old APP23 mice for 6 days showed a significant increase in ABCA1 expression and a decrease in the ratio of soluble APP (sAPP)beta- to sAPPalpha-cleavage products. Most importantly, the treatment caused a statistically significant reduction in the levels of soluble Abeta40 and of Abeta42 in the brain these mice. Our experiments demonstrate that T0901317 decreases amyloidogenic processing of APP in vitro and in vivo, thus supporting the search for potent and specific LXR ligands with properties allowing therapeutic application.
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Affiliation(s)
- Radosveta P Koldamova
- Department of Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.
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