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Galindo CL, Khan S, Zhang X, Yeh YS, Liu Z, Razani B. Lipid-laden foam cells in the pathology of atherosclerosis: shedding light on new therapeutic targets. Expert Opin Ther Targets 2023; 27:1231-1245. [PMID: 38009300 PMCID: PMC10843715 DOI: 10.1080/14728222.2023.2288272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 11/22/2023] [Indexed: 11/28/2023]
Abstract
INTRODUCTION Lipid-laden foam cells within atherosclerotic plaques are key players in all phases of lesion development including its progression, necrotic core formation, fibrous cap thinning, and eventually plaque rupture. Manipulating foam cell biology is thus an attractive therapeutic strategy at early, middle, and even late stages of atherosclerosis. Traditional therapies have focused on prevention, especially lowering plasma lipid levels. Despite these interventions, atherosclerosis remains a major cause of cardiovascular disease, responsible for the largest numbers of death worldwide. AREAS COVERED Foam cells within atherosclerotic plaques are comprised of macrophages, vascular smooth muscle cells, and other cell types which are exposed to high concentrations of lipoproteins accumulating within the subendothelial intimal layer. Macrophage-derived foam cells are particularly well studied and have provided important insights into lipid metabolism and atherogenesis. The contributions of foam cell-based processes are discussed with an emphasis on areas of therapeutic potential and directions for drug development. EXERT OPINION As key players in atherosclerosis, foam cells are attractive targets for developing more specific, targeted therapies aimed at resolving atherosclerotic plaques. Recent advances in our understanding of lipid handling within these cells provide insights into how they might be manipulated and clinically translated to better treat atherosclerosis.
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Affiliation(s)
- Cristi L. Galindo
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine and UPMC, Pittsburgh, PA
| | - Saifur Khan
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine and UPMC, Pittsburgh, PA
| | - Xiangyu Zhang
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine and UPMC, Pittsburgh, PA
| | - Yu-Sheng Yeh
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine and UPMC, Pittsburgh, PA
| | - Ziyang Liu
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine and UPMC, Pittsburgh, PA
| | - Babak Razani
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine and UPMC, Pittsburgh, PA
- Pittsburgh VA Medical Center, Pittsburgh, PA
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Hai Q, Smith JD. Acyl-Coenzyme A: Cholesterol Acyltransferase (ACAT) in Cholesterol Metabolism: From Its Discovery to Clinical Trials and the Genomics Era. Metabolites 2021; 11:metabo11080543. [PMID: 34436484 PMCID: PMC8398989 DOI: 10.3390/metabo11080543] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/10/2021] [Accepted: 08/12/2021] [Indexed: 11/16/2022] Open
Abstract
The purification and cloning of the acyl-coenzyme A: cholesterol acyltransferase (ACAT) enzymes and the sterol O-acyltransferase (SOAT) genes has opened new areas of interest in cholesterol metabolism given their profound effects on foam cell biology and intestinal lipid absorption. The generation of mouse models deficient in Soat1 or Soat2 confirmed the importance of their gene products on cholesterol esterification and lipoprotein physiology. Although these studies supported clinical trials which used non-selective ACAT inhibitors, these trials did not report benefits, and one showed an increased risk. Early genetic studies have implicated common variants in both genes with human traits, including lipoprotein levels, coronary artery disease, and Alzheimer’s disease; however, modern genome-wide association studies have not replicated these associations. In contrast, the common SOAT1 variants are most reproducibly associated with testosterone levels.
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3
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Acidic extracellular pH promotes accumulation of free cholesterol in human monocyte-derived macrophages via inhibition of ACAT1 activity. Atherosclerosis 2020; 312:1-7. [PMID: 32942042 DOI: 10.1016/j.atherosclerosis.2020.08.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 08/14/2020] [Accepted: 08/27/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS In focal areas of advanced human atherosclerotic lesions, the intimal fluid is acidic. An acidic medium impairs the ABCA1-mediated cholesterol efflux from macrophages, so tending to increase their content of free cholesterol, which is then available for esterification by the macrophage enzyme ACAT1. Here we investigated whether low extracellular pH would affect the activity of ACAT1. METHODS - Human monocyte-derived macrophages were first incubated with acetyl-LDL at neutral and acidic conditions (pH 7.5, 6.5, and 5.5) to generate foam cells, and then the foam cells were incubated with [3H]oleate-BSA complexes, and the formation of [3H]oleate-labeled cholesteryl esters was measured. ACAT1 activity was also measured in cell-free macrophage extracts. RESULTS - In acidic media, ACAT1-dependent cholesteryl [3H]oleate generation became compromised in the developing foam cells and their content of free cholesterol increased. In line with this finding, ACAT1 activity in the soluble cell-free fraction derived from macrophage foam cells peaked at pH 7, and gradually decreased under acidic pH with a rapid drop below pH 6.5. Incubation of macrophages under progressively more acidic conditions (until pH 5.5) lowered the cytosolic pH of macrophages (down to pH 6.0). Such intracellular acidification did not affect macrophage gene expression of ACAT1 or the neutral CEH. CONCLUSIONS Exposure of human macrophage foam cells to acidic conditions lowers their intracellular pH with simultaneous decrease in ACAT1 activity. This reduces cholesterol esterification and thus leads to accumulation of potentially toxic levels of free cholesterol, a contributing factor to macrophage foam cell death.
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Melton EM, Li H, Benson J, Sohn P, Huang LH, Song BL, Li BL, Chang CCY, Chang TY. Myeloid Acat1/ Soat1 KO attenuates pro-inflammatory responses in macrophages and protects against atherosclerosis in a model of advanced lesions. J Biol Chem 2019; 294:15836-15849. [PMID: 31495784 DOI: 10.1074/jbc.ra119.010564] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 09/02/2019] [Indexed: 11/06/2022] Open
Abstract
Cholesterol esters are a key ingredient of foamy cells in atherosclerotic lesions; their formation is catalyzed by two enzymes: acyl-CoA:cholesterol acyltransferases (ACATs; also called sterol O-acyltransferases, or SOATs) ACAT1 and ACAT2. ACAT1 is present in all body cells and is the major isoenzyme in macrophages. Whether blocking ACAT1 benefits atherosclerosis has been under debate for more than a decade. Previously, our laboratory developed a myeloid-specific Acat1 knockout (KO) mouse (Acat1 -M/-M), devoid of ACAT1 only in macrophages, microglia, and neutrophils. In previous work using the ApoE KO (ApoE -/-) mouse model for early lesions, Acat1 -M/-M significantly reduced lesion macrophage content and suppressed atherosclerosis progression. In advanced lesions, cholesterol crystals become a prominent feature. Here we evaluated the effects of Acat1 -M/-M in the ApoE KO mouse model for more advanced lesions and found that mice lacking myeloid Acat1 had significantly reduced lesion cholesterol crystal contents. Acat1 -M/-M also significantly reduced lesion size and macrophage content without increasing apoptotic cell death. Cell culture studies showed that inhibiting ACAT1 in macrophages caused cells to produce less proinflammatory responses upon cholesterol loading by acetyl low-density lipoprotein. In advanced lesions, Acat1 -M/-M reduced but did not eliminate foamy cells. In advanced plaques isolated from ApoE -/- mice, immunostainings showed that both ACAT1 and ACAT2 are present. In cell culture, both enzymes are present in macrophages and smooth muscle cells and contribute to cholesterol ester biosynthesis. Overall, our results support the notion that targeting ACAT1 or targeting both ACAT1 and ACAT2 in macrophages is a novel strategy to treat advanced lesions.
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Affiliation(s)
- Elaina M Melton
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire 03755
| | - Haibo Li
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire 03755
| | | | - Paul Sohn
- Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Li-Hao Huang
- Department of Pathology and Immunology, Washington University, St. Louis, Missouri 63130
| | - Bao-Liang Song
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Bo-Liang Li
- Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Catherine C Y Chang
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire 03755
| | - Ta-Yuan Chang
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire 03755
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Wakabayashi T, Takahashi M, Yamamuro D, Karasawa T, Takei A, Takei S, Yamazaki H, Nagashima S, Ebihara K, Takahashi M, Ishibashi S. Inflammasome Activation Aggravates Cutaneous Xanthomatosis and Atherosclerosis in ACAT1 (Acyl-CoA Cholesterol Acyltransferase 1) Deficiency in Bone Marrow. Arterioscler Thromb Vasc Biol 2019; 38:2576-2589. [PMID: 30354239 DOI: 10.1161/atvbaha.118.311648] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Objective- ACAT1 (Acyl-CoA cholesterol acyltransferase 1) esterifies cellular free cholesterol, thereby converting macrophages to cholesteryl ester-laden foam cells in atherosclerotic lesions and cutaneous xanthoma. Paradoxically, however, loss of ACAT1 in bone marrow causes the aggravation of atherosclerosis and the development of severe cutaneous xanthoma in hyperlipidemic mice. Recently, it has been reported that cholesterol crystals activate NLRP3 (NACHT, LRR [leucine-rich repeats], and PYD [pyrin domain] domain-containing protein 3) inflammasomes, thereby contributing to the development of atherosclerosis. The present study aimed to clarify the role of NLRP3 inflammasomes in the worsening of atherosclerosis and cutaneous xanthoma induced by ACAT1 deficiency. Approach and Results- Ldlr-null mice were transplanted with bone marrow from WT (wild type) mice and mice lacking ACAT1, NLRP3, or both. After the 4 types of mice were fed high-cholesterol diets, we compared their atherosclerosis and skin lesions. The mice transplanted with Acat1-null bone marrow developed severe cutaneous xanthoma, which was filled with numerous macrophages and cholesterol clefts and had markedly increased expression of inflammatory cytokines, and increased atherosclerosis. Loss of NLRP3 completely reversed the cutaneous xanthoma, whereas it improved the atherosclerosis only partially. Acat1-null peritoneal macrophages showed enhanced expression of CHOP (C/EBP [CCAAT/enhancer binding protein] homologous protein) and TNF-α (tumor necrosis factor-α) but no evidence of inflammasome activation, after treatment with acetylated LDL (low-density lipoprotein). Conclusions- Elimination of ACAT1 in bone marrow-derived cells aggravates cutaneous xanthoma and atherosclerosis. The development of cutaneous xanthoma is induced mainly via the NLRP3 inflammasome activation.
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Affiliation(s)
- Tetsuji Wakabayashi
- From the Division of Endocrinology and Metabolism, Department of Internal Medicine (T.W., M.T., D.Y., A.T., S.T., H.Y., S.N., K.E., S.I.), Jichi Medical University, Shimotsuke, Japan
| | - Manabu Takahashi
- From the Division of Endocrinology and Metabolism, Department of Internal Medicine (T.W., M.T., D.Y., A.T., S.T., H.Y., S.N., K.E., S.I.), Jichi Medical University, Shimotsuke, Japan
| | - Daisuke Yamamuro
- From the Division of Endocrinology and Metabolism, Department of Internal Medicine (T.W., M.T., D.Y., A.T., S.T., H.Y., S.N., K.E., S.I.), Jichi Medical University, Shimotsuke, Japan
| | - Tadayoshi Karasawa
- Division of Inflammation Research, Center for Molecular Medicine (T.K., M.T.), Jichi Medical University, Shimotsuke, Japan
| | - Akihito Takei
- From the Division of Endocrinology and Metabolism, Department of Internal Medicine (T.W., M.T., D.Y., A.T., S.T., H.Y., S.N., K.E., S.I.), Jichi Medical University, Shimotsuke, Japan
| | - Shoko Takei
- From the Division of Endocrinology and Metabolism, Department of Internal Medicine (T.W., M.T., D.Y., A.T., S.T., H.Y., S.N., K.E., S.I.), Jichi Medical University, Shimotsuke, Japan
| | - Hisataka Yamazaki
- From the Division of Endocrinology and Metabolism, Department of Internal Medicine (T.W., M.T., D.Y., A.T., S.T., H.Y., S.N., K.E., S.I.), Jichi Medical University, Shimotsuke, Japan
| | - Shuichi Nagashima
- From the Division of Endocrinology and Metabolism, Department of Internal Medicine (T.W., M.T., D.Y., A.T., S.T., H.Y., S.N., K.E., S.I.), Jichi Medical University, Shimotsuke, Japan
| | - Ken Ebihara
- From the Division of Endocrinology and Metabolism, Department of Internal Medicine (T.W., M.T., D.Y., A.T., S.T., H.Y., S.N., K.E., S.I.), Jichi Medical University, Shimotsuke, Japan
| | - Masafumi Takahashi
- Division of Inflammation Research, Center for Molecular Medicine (T.K., M.T.), Jichi Medical University, Shimotsuke, Japan
| | - Shun Ishibashi
- From the Division of Endocrinology and Metabolism, Department of Internal Medicine (T.W., M.T., D.Y., A.T., S.T., H.Y., S.N., K.E., S.I.), Jichi Medical University, Shimotsuke, Japan
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Yamazaki H, Takahashi M, Wakabayashi T, Sakai K, Yamamuro D, Takei A, Takei S, Nagashima S, Yagyu H, Sekiya M, Ebihara K, Ishibashi S. Loss of ACAT1 Attenuates Atherosclerosis Aggravated by Loss of NCEH1 in Bone Marrow-Derived Cells. J Atheroscler Thromb 2019; 26:246-259. [PMID: 30282838 PMCID: PMC6402884 DOI: 10.5551/jat.44040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
AIM Acyl-CoA cholesterol acyltransferase 1 (ACAT1) esterifies free cholesterol to cholesteryl esters (CE), which are subsequently hydrolyzed by neutral cholesterol ester hydrolase 1 (NCEH1). The elimination of ACAT1 in vitro reduces the amounts of CE accumulated in Nceh1-deficient macrophages. The present study aimed at examining whether the loss of ACAT1 attenuates atherosclerosis which is aggravated by the loss of NCEH1 in vivo. METHODS Low density lipoprotein receptor (Ldlr)-deficient mice were transplanted with bone marrow from wild-type mice and mice lacking ACAT1, NCEH1, or both. The four types of mice were fed a high-cholesterol diet and, then, were examined for atherosclerosis. RESULTS The cross-sectional lesion size of the recipients of Nceh1-deficient bone marrow was 1.6-fold larger than that of the wild-type bone marrow. The lesions of the recipients of Nceh1-deficient bone marrow were enriched with MOMA2-positive macrophages compared with the lesions of the recipients of the wild-type bone marrow. The size and the macrophage content of the lesions of the recipients of bone marrow lacking both ACAT1 and NCEH1 were significantly smaller than the recipients of the Nceh1-deficient bone marrow, indicating that the loss of ACAT1 decreases the excess CE in the Nceh1-deficient lesions. The collagen-rich and/or mucin-rich areas and en face lesion size were enlarged in the recipients of the Acat1-/- bone marrow compared with those of the recipients of the WT bone marrow. CONCLUSION The loss of ACAT1 in bone marrow-derived cells attenuates atherosclerosis, which is aggravated by the loss of NCEH1, corroborating the in vitro functions of ACAT1 (formation of CE) and NCEH1 (hydrolysis of CE).
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Affiliation(s)
- Hisataka Yamazaki
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University
| | - Manabu Takahashi
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University
| | - Tetsuji Wakabayashi
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University
| | - Kent Sakai
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University
| | - Daisuke Yamamuro
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University
| | - Akihito Takei
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University
| | - Shoko Takei
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University
| | - Shuichi Nagashima
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University
| | - Hiroaki Yagyu
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University
| | - Motohiro Sekiya
- The Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo
| | - Ken Ebihara
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University
| | - Shun Ishibashi
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University
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Shibuya K, Kawamine K, Ozaki C, Ohgiya T, Edano T, Yoshinaka Y, Tsunenari Y. Discovery of Clinical Candidate 2-(4-(2-((1H-Benzo[d]imidazol-2-yl)thio)ethyl)piperazin-1-yl)-N-(6-methyl-2,4-bis(methylthio)pyridin-3-yl)acetamide Hydrochloride [K-604], an Aqueous-Soluble Acyl-CoA:Cholesterol O-Acyltransferase-1 Inhibitor. J Med Chem 2018; 61:10635-10650. [DOI: 10.1021/acs.jmedchem.8b01256] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Kimiyuki Shibuya
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 2-17-43, Noguchicho,
Higashimurayama, Tokyo 189-0022, Japan
| | - Katsumi Kawamine
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 2-17-43, Noguchicho,
Higashimurayama, Tokyo 189-0022, Japan
| | - Chiyoka Ozaki
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 2-17-43, Noguchicho,
Higashimurayama, Tokyo 189-0022, Japan
| | - Tadaaki Ohgiya
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 2-17-43, Noguchicho,
Higashimurayama, Tokyo 189-0022, Japan
| | - Toshiyuki Edano
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 2-17-43, Noguchicho,
Higashimurayama, Tokyo 189-0022, Japan
| | - Yasunobu Yoshinaka
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 2-17-43, Noguchicho,
Higashimurayama, Tokyo 189-0022, Japan
| | - Yoshihiko Tsunenari
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 2-17-43, Noguchicho,
Higashimurayama, Tokyo 189-0022, Japan
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8
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Shibuya K, Kawamine K, Miura T, Ozaki C, Edano T, Mizuno K, Yoshinaka Y, Tsunenari Y. Design, synthesis and pharmacology of aortic-selective acyl-CoA: Cholesterol O-acyltransferase (ACAT/SOAT) inhibitors. Bioorg Med Chem 2018; 26:4001-4013. [DOI: 10.1016/j.bmc.2018.06.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 06/14/2018] [Accepted: 06/16/2018] [Indexed: 10/28/2022]
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Mondal Roy S. Bio-activity of aminosulfonyl ureas in the light of nucleic acid bases and DNA base pair interaction. Comput Biol Chem 2018; 75:91-100. [PMID: 29753268 DOI: 10.1016/j.compbiolchem.2018.04.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 04/21/2018] [Accepted: 04/23/2018] [Indexed: 01/09/2023]
Abstract
The quantum chemical descriptors based on density functional theory (DFT) are applied to predict the biological activity (log IC50) of one class of acyl-CoA: cholesterol O-acyltransferase (ACAT) inhibitors, viz. aminosulfonyl ureas. ACAT are very effective agents for reduction of triglyceride and cholesterol levels in human body. Successful two parameter quantitative structure-activity relationship (QSAR) models are developed with a combination of relevant global and local DFT based descriptors for prediction of biological activity of aminosulfonyl ureas. The global descriptors, electron affinity of the ACAT inhibitors (EA) and/or charge transfer (ΔN) between inhibitors and model biosystems (NA bases and DNA base pairs) along with the local group atomic charge on sulfonyl moiety (∑QSul) of the inhibitors reveals more than 90% efficacy of the selected descriptors for predicting the experimental log (IC50) values.
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Affiliation(s)
- Sutapa Mondal Roy
- Department of Chemistry, Uka Tarsadia University, Maliba Campus, Tarsadi 394 350 India.
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10
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Chang TY, Yamauchi Y, Hasan MT, Chang C. Cellular cholesterol homeostasis and Alzheimer's disease. J Lipid Res 2017; 58:2239-2254. [PMID: 28298292 DOI: 10.1194/jlr.r075630] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 03/14/2017] [Indexed: 01/12/2023] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia in older adults. Currently, there is no cure for AD. The hallmark of AD is the accumulation of extracellular amyloid plaques composed of amyloid-β (Aβ) peptides (especially Aβ1-42) and neurofibrillary tangles, composed of hyperphosphorylated tau and accompanied by chronic neuroinflammation. Aβ peptides are derived from the amyloid precursor protein (APP). The oligomeric form of Aβ peptides is probably the most neurotoxic species; its accumulation eventually forms the insoluble and aggregated amyloid plaques. ApoE is the major apolipoprotein of the lipoprotein(s) present in the CNS. ApoE has three alleles, of which the Apoe4 allele constitutes the major risk factor for late-onset AD. Here we describe the complex relationship between ApoE4, oligomeric Aβ peptides, and cholesterol homeostasis. The review consists of four parts: 1) key elements involved in cellular cholesterol metabolism and regulation; 2) key elements involved in intracellular cholesterol trafficking; 3) links between ApoE4, Aβ peptides, and disturbance of cholesterol homeostasis in the CNS; 4) potential lipid-based therapeutic targets to treat AD. At the end, we recommend several research topics that we believe would help in better understanding the connection between cholesterol and AD for further investigations.
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Affiliation(s)
- Ta-Yuan Chang
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Yoshio Yamauchi
- Nutri-Life Science Laboratory, Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan
| | - Mazahir T Hasan
- Laboratory of Memory Circuits, Achucarro Basque Center for Neuroscience, Zamudio, Spain
| | - Catherine Chang
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
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Inhibition of development of experimental abdominal aortic aneurysm by c-jun N-terminal protein kinase inhibitor combined with lysyl oxidase gene modified smooth muscle progenitor cells. Eur J Pharmacol 2015; 766:114-21. [PMID: 26435026 DOI: 10.1016/j.ejphar.2015.09.046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 09/25/2015] [Accepted: 09/29/2015] [Indexed: 11/23/2022]
Abstract
Chronic inflammation, imbalance between the extracellular matrix synthesis and degradation, and loss of vascular smooth muscle cells (SMCs) contribute to the development of abdominal aortic aneurysm (AAA). The purpose of this study was to investigate the effect of the therapy with periaortic incubation of c-Jun N-terminal protein kinase inhibitor SP600125 infused from an osmotic pump and subadventitial injection of lysyl oxidase (LOX) gene modified autologous smooth muscle progenitor cells (SPCs) on treatment of AAA in a rabbit model. Obvious dilation of the abdominal aorta in the control group was caused by periaortic incubation of calcium chloride and elastase. But the progression of aortic dilation was significantly decreased after the treatment with SP600125 and LOX gene modified SPCs compared to the treatment with phosphate-buffered saline. This therapy could inhibit matrix metalloproteinases expression, enhance elastin synthesis, improve preservation of elastic laminar integrity, benefit SPCs survival and restore SMCs population. It seemed that this method might provide a novel therapeutic strategy to treat AAA.
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12
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Matsuo K, Akakabe Y, Kitamura Y, Shimoda Y, Ono K, Ueyama T, Matoba S, Yamada H, Hatakeyama K, Asada Y, Emoto N, Ikeda K. Loss of apoptosis regulator through modulating IAP expression (ARIA) protects blood vessels from atherosclerosis. J Biol Chem 2014; 290:3784-92. [PMID: 25533470 DOI: 10.1074/jbc.m114.605287] [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: 11/06/2022] Open
Abstract
Atherosclerosis is the primary cause for cardiovascular disease. Here we identified a novel mechanism underlying atherosclerosis, which is provided by ARIA (apoptosis regulator through modulating IAP expression), the transmembrane protein that we recently identified. ARIA is expressed in macrophages present in human atherosclerotic plaque as well as in mouse peritoneal macrophages. When challenged with acetylated LDL, peritoneal macrophages isolated from ARIA-deficient mice showed substantially reduced foam cell formation, whereas the uptake did not differ from that in wild-type macrophages. Mechanistically, loss of ARIA enhanced PI3K/Akt signaling and consequently reduced the expression of acyl coenzyme A:cholesterol acyltransferase-1 (ACAT-1), an enzyme that esterifies cholesterol and promotes its storage, in macrophages. Inhibition of PI3K abolished the reduction in ACAT-1 expression and foam cell formation in ARIA-deficient macrophages. In contrast, overexpression of ARIA reduced Akt activity and enhanced foam cell formation in RAW264.7 macrophages, which was abrogated by treatment with ACAT inhibitor. Of note, genetic deletion of ARIA significantly reduced the atherosclerosis in ApoE-deficient mice. Oil red-O-positive lipid-rich lesion was reduced, which was accompanied by an increase of collagen fiber and decrease of necrotic core lesion in atherosclerotic plaque in ARIA/ApoE double-deficient mice. Analysis of bone marrow chimeric mice revealed that loss of ARIA in bone marrow cells was sufficient to reduce the atherosclerogenesis in ApoE-deficient mice. Together, we identified a unique role of ARIA in the pathogenesis of atherosclerosis at least partly by modulating macrophage foam cell formation. Our results indicate that ARIA could serve as a novel pharmacotherapeutic target for the treatment of atherosclerotic diseases.
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Affiliation(s)
- Kiyonari Matsuo
- From the Department of Cardiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii, Kawaramachi-Hirokoji, Kamigyo, Kyoto 602-8566
| | - Yoshiki Akakabe
- From the Department of Cardiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii, Kawaramachi-Hirokoji, Kamigyo, Kyoto 602-8566
| | - Youhei Kitamura
- From the Department of Cardiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii, Kawaramachi-Hirokoji, Kamigyo, Kyoto 602-8566
| | - Yoshiaki Shimoda
- From the Department of Cardiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii, Kawaramachi-Hirokoji, Kamigyo, Kyoto 602-8566
| | - Kazunori Ono
- From the Department of Cardiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii, Kawaramachi-Hirokoji, Kamigyo, Kyoto 602-8566
| | - Tomomi Ueyama
- From the Department of Cardiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii, Kawaramachi-Hirokoji, Kamigyo, Kyoto 602-8566
| | - Satoaki Matoba
- From the Department of Cardiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii, Kawaramachi-Hirokoji, Kamigyo, Kyoto 602-8566
| | - Hiroyuki Yamada
- From the Department of Cardiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii, Kawaramachi-Hirokoji, Kamigyo, Kyoto 602-8566
| | - Kinta Hatakeyama
- the Department of Pathology, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Yujiro Asada
- the Department of Pathology, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Noriaki Emoto
- the Department of Clinical Pharmacy, Kobe Pharmaceutical University, 4-19-1 Motoyama-Kitamachi, Higashinada, Kobe 6588558, and
| | - Koji Ikeda
- the Department of Clinical Pharmacy, Kobe Pharmaceutical University, 4-19-1 Motoyama-Kitamachi, Higashinada, Kobe 6588558, and
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13
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Arya N, Kharjul MD, Shishoo CJ, Thakare VN, Jain KS. Some molecular targets for antihyperlipidemic drug research. Eur J Med Chem 2014; 85:535-68. [DOI: 10.1016/j.ejmech.2014.08.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 08/01/2014] [Accepted: 08/05/2014] [Indexed: 12/17/2022]
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14
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Acyltransferases and transacylases that determine the fatty acid composition of glycerolipids and the metabolism of bioactive lipid mediators in mammalian cells and model organisms. Prog Lipid Res 2014; 53:18-81. [DOI: 10.1016/j.plipres.2013.10.001] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 07/20/2013] [Accepted: 10/01/2013] [Indexed: 12/21/2022]
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15
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Lu M, Hu XH, Li Q, Xiong Y, Hu GJ, Xu JJ, Zhao XN, Wei XX, Chang CCY, Liu YK, Nan FJ, Li J, Chang TY, Song BL, Li BL. A specific cholesterol metabolic pathway is established in a subset of HCCs for tumor growth. J Mol Cell Biol 2013; 5:404-15. [PMID: 24163426 DOI: 10.1093/jmcb/mjt039] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The liver plays a central role in cholesterol homeostasis. It exclusively receives and metabolizes oxysterols, which are important metabolites of cholesterol and are more cytotoxic than free cholesterol, from all extrahepatic tissues. Hepatocellular carcinomas (HCCs) impair certain liver functions and cause pathological alterations in many processes including cholesterol metabolism. However, the link between an altered cholesterol metabolism and HCC development is unclear. Human ACAT2 is abundantly expressed in intestine and fetal liver. Our previous studies have shown that ACAT2 is induced in certain HCC tissues. Here, by investigating tissue samples from HCC patients and HCC cell lines, we report that a specific cholesterol metabolic pathway, involving induction of ACAT2 and esterification of excess oxysterols for secretion to avoid cytotoxicity, is established in a subset of HCCs for tumor growth. Inhibiting ACAT2 leads to the intracellular accumulation of unesterified oxysterols and suppresses the growth of both HCC cell lines and their xenograft tumors. Further mechanistic studies reveal that HCC-linked promoter hypomethylation is essential for the induction of ACAT2 gene expression. We postulate that specifically blocking this HCC-established cholesterol metabolic pathway may have potential therapeutic applications for HCC patients.
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Affiliation(s)
- Ming Lu
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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16
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Eguchi K, Fujiwara Y, Hayashida A, Horlad H, Kato H, Rotinsulu H, Losung F, Mangindaan REP, de Voogd NJ, Takeya M, Tsukamoto S. Manzamine A, a marine-derived alkaloid, inhibits accumulation of cholesterol ester in macrophages and suppresses hyperlipidemia and atherosclerosis in vivo. Bioorg Med Chem 2013; 21:3831-8. [PMID: 23665143 DOI: 10.1016/j.bmc.2013.04.025] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 04/06/2013] [Accepted: 04/08/2013] [Indexed: 11/28/2022]
Abstract
The formation of foam cells in macrophages plays an essential role in the progression of early atherosclerotic lesions and therefore its prevention is considered to be a promising target for the treatment of atherosclerosis. We found that an extract of the marine sponge Acanthostrongylophora ingens inhibited the foam cell formation induced by acetylated low-density lipoprotein (AcLDL) in human monocyte-derived macrophages, as measured based on the accumulation of cholesterol ester (CE). Bioassay-guided purification of inhibitors from the extract afforded manzamines. Manzamine A was the most potent inhibitor of foam cell formation, and also suppressed CE formation in Chinese hamster ovary cells overexpressing acyl-CoA:cholesterol acyl-transferase (ACAT)-1 or ACAT-2. In addition, manzamine A inhibited ACAT activity. Next, we orally administered manzamine A to apolipoprotein E (apoE)-deficient mice for 80 days, and found that total cholesterol, free cholesterol, LDL-cholesterol, and triglyceride levels in serum were significantly reduced and the area of atherosclerotic lesions in the aortic sinus was also substantially diminished. These findings clearly suggest that manzamine A suppresses hyperlipidemia and atherosclerosis in apoE-deficient mice by inhibiting ACAT and is therefore a promising lead compound in the prevention or treatment of atherosclerosis. Although manzamine A has been reported to show several biological activities, this is the first report of a suppressive effect of manzamine A on atherosclerosis in vivo.
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Affiliation(s)
- Keisuke Eguchi
- Department of Natural Medicines, Graduate School of Pharmaceutical Sciences, Kumamoto University, Oe-honmachi 5-1, Kumamoto 862-0973, Japan
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17
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Choi SY, Lee MH, Choi JH, Kim YK. 2,3,22,23-tetrahydroxyl-2,6,10,15,19,23-hexamethyl-6,10,14,18-tetracosatetraene, an acyclic triterpenoid isolated from the seeds of Alpinia katsumadai, Inhibits acyl-CoA : cholesterol acyltransferase activity. Biol Pharm Bull 2013; 35:2092-6. [PMID: 23123480 DOI: 10.1248/bpb.b12-00617] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In order to isolate a cholesterol-lowering compound from Alpinia katsumadai, an inhibitor for acyl-CoA : cholesterol acyltransferase (ACAT), an enzyme responsible for the cholesterol ester formation in liver, was purified, its chemical structure was determined, and in vivo and in vitro inhibition activities were performed. In a high fat diet mouse model, we discovered that the ethanol extract of Alpinia katsumadai reduced plasma cholesterol, triglyceride, and low density lipoprotein (LDL) levels. An acyclic triterpenoid showing ACAT inhibitory activity was isolated from the extract of seeds of A. katsumadai. By NMR spectroscopic analysis of its (1)H-NMR, (13)C-NMR, (1)H-(1)H correlation spectroscopy, heteronuclear multiple bond connectivity (HMBC), hetero multiquantum coherence (HMQC) and nuclear Overhauser effect, chemical structure of 2,3,22,23-tetrahydroxyl-2,6,10,15,19,23-hexamethyl-6,10,14,18-tetracosatetraene (1), were elucidated. The acyclic triterpenoid was found to be responsible for the ACAT inhibition activities of rat liver microsomes with IC(50) values of 47.9 µM. It also decreased cholesteryl ester formation with IC(50) values of 26 µM in human hepatocyte HepG2 cell. The experimental study revealed that the ethanol extract of A. katsumadai has a hypolipemic effect in high fat diet mice, and the isolated acyclic triterpenoid has ACAT inhibition activity, showing a potential novel therapeutic approach for the treatment of hyperlipidemia and atherosclerosis.
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Affiliation(s)
- Soon-Yong Choi
- Department of Biological Science and Biotechnology, Hannam University, Daejeon 305–811, Korea
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18
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Ogino M, Fukui S, Nakada Y, Tokunoh R, Itokawa S, Kakoi Y, Nishimura S, Sanada T, Fuse H, Kubo K, Wada T, Marui S. Discovery of a potent and orally available acyl-CoA: cholesterol acyltransferase inhibitor as an anti-atherosclerotic agent: (4-phenylcoumarin)acetanilide derivatives. Chem Pharm Bull (Tokyo) 2012; 59:1268-73. [PMID: 21963637 DOI: 10.1248/cpb.59.1268] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Acyl-CoA: cholesterol acyltransferase (ACAT) is an intracellular enzyme that catalyzes cholesterol esterification. ACAT inhibitors are expected to be potent therapeutic agents for the treatment of atherosclerosis. A series of potent ACAT inhibitors based on an (4-phenylcoumarin)acetanilide scaffold was identified. Evaluation of the structure-activity relationships of a substituent on this scaffold, with an emphasis on improving the pharmacokinetic profile led to the discovery of 2-[7-chloro-4-(3-chlorophenyl)-6-methyl-2-oxo-2H-chromen-3-yl]-N-[4-chloro-2-(trifluoromethyl)phenyl]acetamide (23), which exhibited potent ACAT inhibitory activity (IC50=12 nM) and good pharmacokinetic profile in mice. Compound 23 also showed regressive effects on atherosclerotic plaques in apolipoprotein (apo)E knock out (KO) mice at a dose of 0.3 mg/kg per os (p.o.).
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Affiliation(s)
- Masaki Ogino
- Pharmaceutical Research Division, Takeda Pharmaceutical Co., Ltd., Kanagawa, Japan.
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19
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Fujiwara Y, Kiyota N, Tsurushima K, Yoshitomi M, Horlad H, Ikeda T, Nohara T, Takeya M, Nagai R. Tomatidine, a tomato sapogenol, ameliorates hyperlipidemia and atherosclerosis in apoE-deficient mice by inhibiting acyl-CoA:cholesterol acyl-transferase (ACAT). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:2472-2479. [PMID: 22224814 DOI: 10.1021/jf204197r] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
It was previously revealed that esculeoside A, a new glycoalkaloid, and esculeogenin A, a new aglycon of esculeoside A, contained in ripe tomato ameliorate atherosclerosis in apoE-deficent mice. This study examined whether tomatidine, the aglycone of tomatine, which is a major tomato glycoalkaloid, also shows similar inhibitory effects on cholesterol ester (CE) accumulation in human monocyte-derived macrophages (HMDM) and atherogenesis in apoE-deficient mice. Tomatidine significantly inhibited the CE accumulation induced by acetylated LDL in HMDM in a dose-dependent manner. Tomatidine also inhibited CE formation in Chinese hamster ovary cells overexpressing acyl-CoA:cholesterol acyl-transferase (ACAT)-1 or ACAT-2, suggesting that tomatidine suppresses both ACAT-1 and ACAT-2 activities. Furthermore, the oral administration of tomatidine to apoE-deficient mice significantly reduced levels of serum cholesterol, LDL-cholesterol, and areas of atherosclerotic lesions. The study provides the first evidence that tomatidine significantly suppresses the activity of ACAT and leads to reduction of atherogenesis.
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Affiliation(s)
- Yukio Fujiwara
- Department of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
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20
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Ogino M, Nakada Y, Negoro N, Itokawa S, Nishimura S, Sanada T, Satomi T, Kita S, Kubo K, Marui S. Discovery of a novel acyl-CoA: cholesterol acyltransferase inhibitor: the synthesis, biological evaluation, and reduced adrenal toxicity of (4-phenylcoumarin)acetanilide derivatives with a carboxylic acid moiety. Chem Pharm Bull (Tokyo) 2012; 59:1369-75. [PMID: 22041073 DOI: 10.1248/cpb.59.1369] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
As a part of our research for novel potent and orally available acyl-CoA: cholesterol acyltransferase (ACAT) inhibitors that can be used as anti-atherosclerotic agents, we recently reported the discovery of the (4-phenylcoumarine)acetanilide derivative 1. However, compound 1 showed adrenal toxicity in animal models. In order to search for safer ACAT inhibitors that do not have adrenal toxicity, we examined the inhibitory activity of ACAT in human macrophage and adrenal cells. The introduction of a carboxylic acid moiety on the pendant phenyl ring and the adjustment of the lipophilicity led to the discovery of (2E)-3-[7-chloro-3-[2-[[4-fluoro-2-(trifluoromethyl)phenyl]amino]-2-oxoethyl]-6-methyl-2-oxo-2H-chromen-4-yl]phenyl]acrylic acid (21e), which showed potent ACAT inhibitory activity in macrophages and a selectivity of around 30-fold over adrenal cells. In addition, compound 21e showed high adrenal safety in guinea pigs.
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Affiliation(s)
- Masaki Ogino
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd., Fujisawa, Kanagawa 251–8555, Japan.
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21
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Isoform-specific inhibitors of ACATs: recent advances and promising developments. Future Med Chem 2011; 3:2039-61. [DOI: 10.4155/fmc.11.158] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Acyl-CoA:cholesterol acyltransferase (ACAT) is a promising therapeutic target for cardiovascular diseases. Although a number of synthetic ACAT inhibitors have been developed, they have failed to show efficacy in clinical trials. Now, the presence of two ACAT isoforms with distinct functions, ACAT1 and ACAT2, has been discovered. Thus, the selectivity of ACAT inhibitors toward the two isoforms is important for their development as novel anti-atherosclerotic agents. The selectivity study indicated that fungal pyripyropene A (PPPA) is only an ACAT2-specific inhibitor. Furthermore, PPPA proved orally active in atherogenic mouse models, indicating it possessed cholesterol-lowering and atheroprotective activities. Certain PPPA derivatives, semi-synthetically prepared, possessed more potent and selective in vitro activity than PPPA against ACAT2. This review covers these studies and describes the future prospects of ACAT2-specific inhibitors.
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22
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Lu Z, Yuan Z, Miyoshi T, Wang Q, Su Z, Chang CC, Shi W. Identification of Soat1 as a quantitative trait locus gene on mouse chromosome 1 contributing to hyperlipidemia. PLoS One 2011; 6:e25344. [PMID: 22022387 PMCID: PMC3194806 DOI: 10.1371/journal.pone.0025344] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 09/01/2011] [Indexed: 11/18/2022] Open
Abstract
We previously identified two closely linked quantitative trait loci (QTL) on distal chromosome 1 contributing to major variations in plasma cholesterol and triglyceride levels in an intercross derived from C57BL/6 (B6) and C3H/HeJ (C3H) apolipoprotein E-deficient (apoE−/−) mice. Soat1, encoding sterol o-acyltransferase 1, is a functional candidate gene located underneath the proximal linkage peak. We sequenced the coding region of Soat1 and identified four single nucleotide polymorphisms (SNPs) between B6 and C3H mice. Two of the SNPs resulted in amino-acid substitutions (Ile147Val and His205Tyr). Functional assay revealed an increased enzyme activity of Soat1 in peritoneal macrophages of C3H mice relative to those of B6 mice despite comparable protein expression levels. Allelic variants of Soat1 were associated with variations in plasma cholesterol and triglyceride levels in an intercross between B6.apoE−/− and C3H.apoE−/− mice. Inheritance of the C3H allele resulted in significantly higher plasma lipid levels than inheritance of the B6 allele. Soat1 variants were also significantly linked to major variations in plasma esterified cholesterol levels but not with free cholesterol levels. Trangenic expression of C3H Soat1 in B6.apoE−/− mice resulted in elevations of plasma cholesterol and triglyceride levels. These results indicate that Soat1 is a QTL gene contributing to hyperlipidemia.
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Affiliation(s)
- Zongji Lu
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, United States of America
| | - Zuobiao Yuan
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, United States of America
| | - Toru Miyoshi
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, United States of America
| | - Qian Wang
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, United States of America
| | - Zhiguang Su
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, United States of America
| | - Catherine C. Chang
- Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire, United States of America
| | - Weibin Shi
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, United States of America
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, Virginia, United States of America
- * E-mail:
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23
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Ghosh S. Macrophage cholesterol homeostasis and metabolic diseases: critical role of cholesteryl ester mobilization. Expert Rev Cardiovasc Ther 2011; 9:329-40. [PMID: 21438812 DOI: 10.1586/erc.11.16] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Atherogenic dyslipidemia, including low HDL levels, is the major contributor of residual risk of cardiovascular disease that remains even after aggressive statin therapy to reduce LDL-cholesterol. Currently, distinction is not made between HDL-cholesterol and HDL, which is a lipoprotein consisting of several proteins and a core containing cholesteryl esters (CEs). The importance of assessing HDL functionality, specifically its role in facilitating cholesterol efflux from foam cells, is relevant to atherogenesis. Since HDLs can only remove unesterified cholesterol from macrophages while cholesterol is stored as CEs within foam cells, intracellular CE hydrolysis by CE hydrolase is vital. Reduction in macrophage lipid burden not only attenuates atherosclerosis but also reduces inflammation and linked pathologies such as Type 2 diabetes and chronic kidney disease. Targeting reduction in macrophage CE levels and focusing on enhancing cholesterol flux from peripheral tissues to liver for final elimination is proposed.
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Affiliation(s)
- Shobha Ghosh
- Department of Internal Medicine, Division of Pulmonary and Critical Care, VCU Medical Center, Richmond, VA 23298-0050, USA.
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24
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Vaziri ND. Lipotoxicity and impaired high density lipoprotein-mediated reverse cholesterol transport in chronic kidney disease. J Ren Nutr 2011; 20:S35-43. [PMID: 20797569 DOI: 10.1053/j.jrn.2010.05.010] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Chronic kidney disease (CKD) is associated with a high risk of death from cardiovascular disease. Inflammation, oxidative stress, and dyslipidemia, which are common consequences of CKD, contribute to the pathogenesis of atherosclerosis and cardiovascular disease in this population. Dyslipidemia of CKD is characterized by diminished plasma high density lipoprotein (HDL) concentration, impaired HDL anti-oxidant and anti-inflammatory activities, and elevated plasma triglyceride, very low density lipoprotein (VLDL), intermediate density lipoprotein, chylomicron remnants, and oxidized lipids and lipoproteins. The constellation of inflammation, HDL deficiency, and oxidative modification of lipoproteins can cause atherosclerosis and progression of renal disease. We have recently found lipid accumulation in the remnant kidney and the wall of aorta in rats with CKD induced by 5/6 nephrectomy. This was mediated by up-regulation of scavenger receptors involved in the influx of oxidized lipids or lipoproteins, tubular reabsorption of lipid binding proteins through megalin-cubilin complexes, upregulation of fatty acid synthesis, and downregulation of fatty acid oxidation pathways. The combination of increased lipid influx, elevated production and reduced catabolism of lipids, and impaired HDL-mediated reverse cholesterol transport can promote atherosclerosis, glomerulosclerosis, and tubulointerstitial damage. Although statins can be effective in slowing CKD progression in patients with mild-to-moderate CKD, they have consistently failed to mitigate oxidative stress, inflammation, HDL deficiency, or cardiovascular mortality in the end-stage renal disease populations. Similarly, high doses of antioxidant vitamins have failed to either ameliorate oxidative stress, inflammation, or improve overall mortality in end-stage renal disease. This article is intended to provide a brief review of the effects of CKD on HDL structure and function and pathways of lipid influx, efflux, synthesis, and catabolism in the artery wall and the diseased kidney.
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Affiliation(s)
- Nosratola D Vaziri
- Division of Nephrology and Hypertension, Department of Medicine, University of California, Irvine, California, USA.
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25
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Nohara T, Ono M, Ikeda T, Fujiwara Y, El-Aasr M. The tomato saponin, esculeoside A. JOURNAL OF NATURAL PRODUCTS 2010; 73:1734-1741. [PMID: 20853874 DOI: 10.1021/np100311t] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Esculeoside A (2), a spirosolane steroidal glycoside, is a major constituent isolated from Solanum lycopersicum, a commercial strain of mini tomatoes. The content variability of esculeoside A (2) was examined in mini, midi, and Momotaro tomatoes and various processed tomato products. In the green immature tomato fruit, tomatine (1) is oxidized at C-23 and C-27 to produce esculeoside A (2) in the ripe fruit. Further, esculeoside A (2) is partly converted to 3β-hydroxy-5α-pregn-16-en-20-one 3-O-β-lycotetraoside (6), a pregnane glycoside, in the overripe fruit. Esculeogenin A (3), the sapogenol of 2, is easily converted into 3β,16β-dihydroxy-5α-pregn-20-one (17). Metabolic studies showed excretion of androstane derivatives in the urine of human volunteer subjects after tomato consumption. Esculeogenin A (3) inhibited the accumulation of cholesterol esters in macrophages through its effects on acyl-CoA:cholesterol acyl transferase (ACAT). Oral administration of esculeoside A (2) to apoE-deficient mice significantly reduced serum levels of cholesterol, triglycerides, and LDL-cholesterol and ameliorated the severity of atherosclerotic lesions.
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Affiliation(s)
- Toshihiro Nohara
- Faculty of Pharmaceutical Sciences, Sojo University, 22-1, 4-Chome, Ikeda, Kumamoto 860-0082, Japan.
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26
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Nicholls SJ, Uno K, Tuzcu EM, Nissen SE. Intracoronary Ultrasound in Assessing Efficacy of Cardiovascular Drugs. CURRENT CARDIOVASCULAR IMAGING REPORTS 2010. [DOI: 10.1007/s12410-010-9027-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Chronic kidney disease (CKD) is associated with development of atherosclerosis and premature death from cardiovascular disease. The predisposition of patients with CKD to atherosclerosis is driven by inflammation, oxidative stress and dyslipidemia, all of which are common features of this condition. Markers of dyslipidemia in patients with advanced CKD are impaired clearance and heightened oxidation of apolipoprotein-B-containing lipoproteins and their atherogenic remnants, and a reduction of the plasma concentration, antioxidant, and anti-inflammatory properties of high-density lipoprotein (HDL). Studies in animal models of CKD indicate that the disease promotes lipid accumulation in the artery wall and kidney, leading to atherosclerosis, glomerulosclerosis and tubulointerstitial injury. These effects seem to be mediated by an increased cellular influx of lipids, elevated cellular production and reduced cellular catabolism of fatty acids, and impaired antioxidant, anti-inflammatory and reverse lipid transport properties of HDL. Available pharmacological therapies have been largely ineffective in ameliorating oxidative stress, inflammation, HDL deficiency and/or dysfunction, and the associated atherosclerosis and cardiovascular disease in patients with end-stage renal disease. This Review aims to provide an overview of the mechanisms and consequences of CKD-induced HDL deficiency and dysfunction.
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28
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Kim HJ, Yuan J, Norris K, Vaziri ND. High-calorie diet partially ameliorates dysregulation of intrarenal lipid metabolism in remnant kidney. J Nutr Biochem 2009; 21:999-1007. [PMID: 19954950 DOI: 10.1016/j.jnutbio.2009.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2009] [Accepted: 08/20/2009] [Indexed: 01/01/2023]
Abstract
Chronic renal failure (CRF) is associated with malnutrition and renal tissue accumulation of lipids, which can contribute to progression of renal disease. This study was designed to explore the effect of a high-calorie diet on pathways involved in lipid metabolism in the remnant kidney of rats with CRF. 5/6 nephrectomized rats were randomized to receive a regular diet (3.0 kcal/g) or a high-calorie diet (4.5 kcal/g) for 12 weeks. Renal lipid contents and abundance of molecules involved in cholesterol and fatty acid metabolism were studied. The CRF group consuming a regular diet exhibited growth retardation; azotemia; proteinuria; glomerulosclerosis; tubulointerstitial injury; heavy lipid accumulation in the remnant kidney; up-regulation of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), ATP-binding cassette transporter-1 (ABCA1), liver X receptor (LXR) α/β, carbohydrate-responsive element binding protein (ChREBP) and acyl-CoA carboxylase (ACC); and down-regulation of peroxisome proliferator-activated receptor-α (PPAR-α), carnitine palmitoyltransferase-1 (CPT1) and liver-type fatty acid binding protein (L-FABP). The high-calorie diet restored growth; reduced the severity of tubulointerstitial injury, proteinuria and azotemia; partially lowered renal tissue lipid contents; attenuated the up-regulation of mediators of lipid influx (LOX-1), lipid efflux (LXR-α/β and ABCA1) and fatty acid biosynthesis (ChREBP and ACC); and reversed the down-regulation of factors involved in fatty acid oxidation (PPAR-α, CPT1 and L-FABP). In conclusion, a high-calorie diet restores growth, improves renal function and structure, and lowers lipid burden in the remnant kidney. The latter is associated with and most likely due to reduction in lipid influx and enhancement of fatty acid oxidation.
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Affiliation(s)
- Hyun Ju Kim
- Division of Nephrology and Hypertension, University of California, Irvine, Orange, CA 92868, USA
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29
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Cho KH, Kim HJ, Kamanna VS, Vaziri ND. Niacin improves renal lipid metabolism and slows progression in chronic kidney disease. Biochim Biophys Acta Gen Subj 2009; 1800:6-15. [PMID: 19878707 DOI: 10.1016/j.bbagen.2009.10.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 09/01/2009] [Accepted: 10/21/2009] [Indexed: 01/04/2023]
Abstract
BACKGROUND Mounting evidence points to lipid accumulation in the diseased kidney and its contribution to progression of nephropathy. We recently found heavy lipid accumulation and marked dysregulation of lipid metabolism in the remnant kidneys of rats with chronic renal failure (CRF). Present study sought to determine efficacy of niacin supplementation on renal tissue lipid metabolism in CRF. METHODS Kidney function, lipid content, and expression of molecules involved in cholesterol and fatty acid metabolism were determined in untreated CRF (5/6 nephrectomized), niacin-treated CRF (50 mg/kg/day in drinking water for 12 weeks) and control rats. RESULTS CRF resulted in hypertension, proteinuria, renal tissue lipid accumulation, up-regulation of scavenger receptor A1 (SR-A1), acyl-CoA cholesterol acyltransferase-1 (ACAT1), carbohydrate-responsive element binding protein (ChREBP), fatty acid synthase (FAS), acyl-CoA carboxylase (ACC), liver X receptor (LXR), ATP binding cassette (ABC) A-1, ABCG-1, and SR-B1 and down-regulation of sterol responsive element binding protein-1 (SREBP-1), SREBP-2, HMG-CoA reductase, PPAR-alpha, fatty acid binding protein (L-FABP), and CPT1A. Niacin therapy attenuated hypertension, proteinuria, and tubulo-interstitial injury, reduced renal tissue lipids, CD36, ChREBP, LXR, ABCA-1, ABCG-1, and SR-B1 abundance and raised PPAR-alpha and L-FABP. CONCLUSIONS AND GENERAL SIGNIFICANCE Niacin administration improves renal tissue lipid metabolism and renal function and structure in experimental CRF.
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Affiliation(s)
- Kyu-hyang Cho
- Division of Nephrology and Hypertension, University of California, Irvine, Irvine, CA, USA
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30
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Ghosh S, Zhao B, Bie J, Song J. Macrophage cholesteryl ester mobilization and atherosclerosis. Vascul Pharmacol 2009; 52:1-10. [PMID: 19878739 DOI: 10.1016/j.vph.2009.10.002] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Revised: 09/30/2009] [Accepted: 10/09/2009] [Indexed: 11/26/2022]
Abstract
Accumulation of cholesteryl esters (CE) stored as cytoplasmic lipid droplets is the main characteristic of macrophage foam cells that are central to the development of atherosclerotic plaques. Since only unesterified or free cholesterol (FC) can be effluxed from the cells to extracellular cholesterol acceptors, hydrolysis of CE is the obligatory first step in CE mobilization from macrophages. This reaction, catalyzed by neutral cholesteryl ester hydrolase (CEH), is increasingly being recognized as the rate-limiting step in FC efflux. CEH, therefore, regulates the process of reverse cholesterol transport and ultimate elimination of cholesterol from the body. In this review, we summarize the earlier controversies surrounding the identity of CEH in macrophages, discuss the characteristics of the various candidates recognized to date and examine their role in mobilizing cellular CE and thus regulating atherogenesis. In addition, physiological requirements to hydrolyze lipid droplet-associated substrate and complexities of interfacial catalysis are also discussed to emphasize the importance of evaluating the biochemical characteristics of candidate enzymes that may be targeted in the future to attenuate atherosclerosis.
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Affiliation(s)
- Shobha Ghosh
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298-0050, USA.
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Ghosh S, Zhao B, Bie J, Song J. Role of cholesteryl ester hydrolase in atherosclerosis. ACTA ACUST UNITED AC 2009. [DOI: 10.2217/clp.09.52] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
The enzymes acyl-coenzyme A (CoA):cholesterol acyltransferases (ACATs) are membrane-bound proteins that utilize long-chain fatty acyl-CoA and cholesterol as substrates to form cholesteryl esters. In mammals, two isoenzymes, ACAT1 and ACAT2, encoded by two different genes, exist. ACATs play important roles in cellular cholesterol homeostasis in various tissues. This chapter summarizes the current knowledge on ACAT-related research in two areas: 1) ACAT genes and proteins and 2) ACAT enzymes as drug targets for atherosclerosis and for Alzheimer's disease.
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Affiliation(s)
- Ta-Yuan Chang
- Department of Biochemistry, Dartmouth Medical School, 1 Rope Ferry Rd., Hanover, NH 03755-1404, USA.
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Kim HJ, Moradi H, Yuan J, Norris K, Vaziri ND. Renal mass reduction results in accumulation of lipids and dysregulation of lipid regulatory proteins in the remnant kidney. Am J Physiol Renal Physiol 2009; 296:F1297-306. [PMID: 19357177 DOI: 10.1152/ajprenal.90761.2008] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A significant reduction of renal mass results in proteinuria, glomerulosclerosis, and tubulointerstitial injury, culminating in end-stage chronic renal failure (CRF). The accumulation of lipids in the kidney can cause renal disease. Uptake of oxidized lipoproteins via scavenger receptors, reabsorption of filtered protein-bound lipids via the megalin-cubilin complex, and increased glucose load per nephron can promote lipid accumulation in glomerular, tubular, and interstitial cells in CRF. Cellular lipid homeostasis is regulated by lipid influx, synthesis, catabolism, and efflux. We examined lipid-regulatory factors in the remnant kidney of rats 11 wk after nephrectomy (CRF) or sham operation. CRF resulted in azotemia, proteinuria, lipid accumulation in the kidney, upregulation of megalin, cubilin, mediators of lipid influx (scavenger receptor class A and lectin-like oxidized receptor-1), lipid efflux (liver X receptor alpha/beta and ATP-binding cassette transporter), and fatty acid biosynthesis (carbohydrate-response element binding protein, fatty acid synthase, and acetyl-CoA carboxylase). However, factors involved in cholesterol biosynthesis (sterol regulatory element binding protein, 3-hydroxy-3-methylglutaryl coenzyme A reductase, SCAP, Insig-1, and Insig-2) and fatty acid oxidation (peroxisome proliferator-activated receptor, acyl-CoA oxidase, and liver-type fatty acid binding protein) were reduced in the remnant kidney. Thus CRF results in heavy lipid accumulation in the remnant kidney, which is mediated by upregulation of pathways involved in tubular reabsorption of filtered protein-bound lipids, influx of oxidized lipoproteins and synthesis of fatty acids, and downregulation of pathways involved in fatty acid catabolism.
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Affiliation(s)
- Hyun Ju Kim
- Division of Nephrology and Hypertension, University of California, 101 The City Dr., Bldg. 53, Rm. 125, Rt. 81, Orange, CA 92868, USA
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Choi JH, Rho MC, Lee SW, Choi JN, Kim K, Song GY, Kim YK. Bavachin and isobavachalcone, acyl-coenzyme A: Cholesterol acyltransferase inhibitors from Psoralea corylifolia. Arch Pharm Res 2008; 31:1419-23. [DOI: 10.1007/s12272-001-2126-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Revised: 11/05/2008] [Accepted: 11/06/2008] [Indexed: 11/28/2022]
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Worthley SG, Helft G, Corti R, Worthley MI, Chew DP, Fayad ZA, Zaman AG, Fallon JT, Fuster V, Badimon JJ. Statin Therapy Alone and in Combination with an Acyl-CoA:Cholesterol O-Acyltransferase Inhibitor on Experimental Atherosclerosis. PATHOPHYSIOLOGY OF HAEMOSTASIS AND THROMBOSIS 2008; 36:9-17. [DOI: 10.1159/000112634] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Accepted: 04/06/2007] [Indexed: 11/19/2022]
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Adameová A, Ravingerová T, Svec P, Faberová V, Kuzelová M. The myocardial infarct size-limiting and antiarrhythmic effects of acyl-CoA:cholesterol acyltransferase inhibitor VULM 1457 protect the hearts of diabetic-hypercholesterolaemic rats against ischaemia/reperfusion injury both in vitro and in vivo. Eur J Pharmacol 2007; 576:114-21. [PMID: 17764671 DOI: 10.1016/j.ejphar.2007.07.064] [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: 03/12/2007] [Revised: 07/25/2007] [Accepted: 07/26/2007] [Indexed: 11/28/2022]
Abstract
The study was designed to characterise the influence of a novel acyl-CoA:cholesterol acyltransferase inhibitor, VULM 1457, on the severity of myocardial ischaemia-reperfusion injury in a model of diabetes mellitus and hypercholesterolaemia induced by co-administration of streptozotocin and a high fat-cholesterol diet. We used Langendorff-perfused rat hearts to measure the size of myocardial infarction after 30 min of regional ischaemia, followed by a 2-h reperfusion period, and open-chest rats were exposed to 6 min of ischaemia and 10 min of reperfusion to analyse ventricular arrhythmias. In addition to the high fat-cholesterol diet, VULM 1457 was administered to the diabetic-hypercholesterolaemic rats for 5 days. Decreased plasma and liver cholesterol levels and a significantly reduced occurrence of ventricular fibrillation (29% vs. 100%, P<0.01), determined via the mean number and duration of episodes (0.6+/-0.4 and 2.1+/-1.4 s vs. 2.8+/-0.8 and 53.5+/-14.4 s in diabetic-hypercholesterolaemic rats, both P<0.01), were observed in these animals. Lethal ventricular fibrillation was suppressed, and arrhythmia severity was also significantly decreased in these animals as compared to the non-treated animals (2.9+/-0.6 vs. 4.9+/-0.2; P<0.05). A smaller infarct size, normalised to the size of area at risk, was observed in the treated diabetic-hypercholesterolaemic group as compared to the non-treated group (16.3+/-1.9% vs. 37.3+/-3.1%; P<0.01). Aside from remarkable hypolipidaemic activity, VULM 1457 improved the overall myocardial ischaemia-reperfusion injury outcomes in the diabetic-hypercholesterolaemic rats by suppressing arrhythmogenesis as well as by reducing myocardial necrosis.
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Affiliation(s)
- Adriana Adameová
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University, Odbojarov 10, 832 32 Bratislava, Slovak Republic.
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Choi JH, Rho MC, Lee SW, Kwon OE, Park HR, Kang JY, Lee SH, Lee HS, Bae KH, Kim YK. Glabrol, an acyl-coenzyme A: cholesterol acyltransferase inhibitor from licorice roots. JOURNAL OF ETHNOPHARMACOLOGY 2007; 110:563-6. [PMID: 17123760 DOI: 10.1016/j.jep.2006.10.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Revised: 09/27/2006] [Accepted: 10/13/2006] [Indexed: 05/12/2023]
Abstract
Acyl-coenzyme A: cholesterol acyltransferase (ACAT) esterifies free cholesterol in the liver and the intestine. It has relations with production of lipoproteins and accumulation of cholesteryl esters of the atheroma. Therefore, ACAT inhibitors may act as antihypercholesterolemic and antiatherosclerotic agents. One isoprenyl flavonoid was isolated from ethanol extract of licorice roots. On the basis of spectral evidences, the compound was identified as glabrol (1). Compound 1 inhibited rat liver microsomal ACAT activity with an IC(50) value of 24.6 microM and decreased cholesteryl ester formation with an IC(50) value of 26.0 microM in HepG2 cells. In addition, 1 showed a non-competitive type of inhibition against ACAT.
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Affiliation(s)
- Jung Ho Choi
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, 52 Eoun-dong, Yusong-gu, Daejeon 305-333, Republic of Korea
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Ikenoya M, Yoshinaka Y, Kobayashi H, Kawamine K, Shibuya K, Sato F, Sawanobori K, Watanabe T, Miyazaki A. A selective ACAT-1 inhibitor, K-604, suppresses fatty streak lesions in fat-fed hamsters without affecting plasma cholesterol levels. Atherosclerosis 2007; 191:290-7. [PMID: 16820149 DOI: 10.1016/j.atherosclerosis.2006.05.048] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2005] [Revised: 05/01/2006] [Accepted: 05/19/2006] [Indexed: 11/29/2022]
Abstract
BACKGROUND Acyl-coenzyme A:cholesterol O-acyltransferase-1 (ACAT-1), a major ACAT isozyme in macrophages, plays an essential role in foam cell formation in atherosclerotic lesions. However, whether pharmacological inhibition of macrophage ACAT-1 causes exacerbation or suppression of atherosclerosis is controversial. METHODS AND RESULTS We developed and characterized a novel ACAT inhibitor, K-604. The IC(50) values of K-604 for human ACAT-1 and ACAT-2 were 0.45 and 102.85 micromol/L, respectively, indicating that K-604 is 229-fold more selective for ACAT-1. Kinetic analysis indicated that the inhibition was competitive with respect to oleoyl-coenzyme A with a K(i) value of 0.378 micromol/L. Exposure of human monocyte-derived macrophages to K-604 inhibited cholesterol esterification with IC(50) of 68.0 nmol/L. Furthermore, cholesterol efflux from THP-1 macrophages to HDL(3) or apolipoprotein A-I was enhanced by K-604. Interestingly, administration of K-604 to F1B hamsters on a high-fat diet at a dose of >or=1mg/kg suppressed fatty streak lesions without affecting plasma cholesterol levels. CONCLUSIONS K-604, a potent and selective inhibitor of ACAT-1, suppressed the development of atherosclerosis in an animal model without affecting plasma cholesterol levels, providing direct evidence that pharmacological inhibition of ACAT-1 in the arterial walls leads to suppression of atherosclerosis.
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Affiliation(s)
- Mami Ikenoya
- Tokyo New Research Laboratories I, Pharmaceutical Division, Kowa Company Ltd., 2-17-43 Noguchicho, Higashimurayama, Tokyo 189-0022, Japan.
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Kitamura A, Imai S, Yabuki M, Komuro S. The new acyl-CoA cholesterol acyltransferase inhibitor SMP-797 does not interact with statins via OATP1B1 in human cryopreserved hepatocytes and oocytes expressing systems. Biopharm Drug Dispos 2007; 28:517-25. [DOI: 10.1002/bdd.581] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Abstract
Although many studies have documented that reduction of plasma cholesterol levels decreases the risk of coronary artery disease, it remains the most common cause of death in the Western world. Current therapeutic options are effective in lowering cholesterol, especially in clinical trials, but clinical application is not optimized for many reasons. Dietary restriction for long-term management of hypercholesterolemia is helpful but usually insufficient to reduce low-density lipoprotein cholesterol (LDL-C) to goal levels. Powerful drugs are available, but these are often insufficient to meet the clinical demands for cholesterol-lowering therapy. Phytosterols and phytostanols have been partially effective by providing some inhibition of absorption of cholesterol. Compounds that specifically and more effectively block intestinal absorption of dietary and biliary cholesterol should provide a significant new agent for altering lipoprotein concentrations favorably. Ezetimibe is the first of this class of compounds that act at the gut epithelium to reduce cholesterol absorption in the milligram dose range markedly. Clinical studies indicate that ezetimibe effectively decreases LDL-C by 15 to 20% as monotherapy, with a favorable safety profile. Moreover, results from preliminary clinical trials indicate that ezetimibe given concomitantly with a statin provides additive efficacy. The combination represents a new approach to lipid management, achieving greater LDL-C and triglyceride reductions and greater improvements in HDL-C than statin monotherapy. This could offer another important option in clinical practice for management of hypercholesterolemic patients.
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Affiliation(s)
- W Virgil Brown
- Emory University School of Medicine, Atlanta, Georgia, USA.
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Abstract
Once the physiological function of an enzyme is understood, a rationale for therapeutic intervention often becomes apparent. It is much harder to find synthetic inhibitors with the required specificity and safety. Preclinical biological data packages are not always predictive of the response in humans. Rational targets, therefore, go in and out of fashion according to the status of candidate drugs. Acyl-CoA:cholesterol acyltransferase and squalene synthase inhibitors have been studied for many years, but safety and early clinical data did not support progression. In recent months, data have become available on new compounds for each target which suggest a way forward. This editorial reviews the difficulties and potential for each target in the light of recent reports.
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Meuwese MC, Franssen R, Stroes ESG, Kastelein JJP. And then there were acyl coenzyme A:cholesterol acyl transferase inhibitors. Curr Opin Lipidol 2006; 17:426-30. [PMID: 16832167 DOI: 10.1097/01.mol.0000236369.50378.6e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW The reputation of acyl coenzyme A:cholesterol acyltransferase (ACAT) inhibitors has changed profoundly from promising new drugs for cardiovascular prevention to drugs without clinical benefits or possibly even with adverse effects. RECENT FINDINGS ACAT inhibitors decrease the intracellular conversion of free cholesterol into cholesteryl ester in a number of tissues, including intestine, liver and macrophages. In contrast to promising results in experimental animal models, all subsequent clinical studies in humans with ACAT inhibitors failed to show lipid profile changes as well as reductions in surrogate markers for coronary artery disease. In fact, there was even a tendency towards an increase in atheroma burden in the most recent and well executed clinical trials. In addition, the inhibition of this pivotal enzyme in cholesterol esterification may interfere with reverse cholesterol transport. SUMMARY In our opinion, the consistent negative findings in recent clinical trials have virtually eliminated the chances for this class of drugs to be introduced for cardiovascular prevention. Possible strategies focused on selective ACAT 2 inhibition or the combination of ACAT inhibitors with compounds that stimulate reverse cholesterol transport may prove to have clinical benefit. This will have to await further clinical research in humans, however, as, obviously, rodent models cannot provide reliable data as to the efficacy of this class of drugs in humans.
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Affiliation(s)
- Marijn C Meuwese
- Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands
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Nissen SE, Tuzcu EM, Brewer HB, Sipahi I, Nicholls SJ, Ganz P, Schoenhagen P, Waters DD, Pepine CJ, Crowe TD, Davidson MH, Deanfield JE, Wisniewski LM, Hanyok JJ, Kassalow LM. Effect of ACAT inhibition on the progression of coronary atherosclerosis. N Engl J Med 2006; 354:1253-63. [PMID: 16554527 DOI: 10.1056/nejmoa054699] [Citation(s) in RCA: 295] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND The enzyme acyl-coenzyme A:cholesterol acyltransferase (ACAT) esterifies cholesterol in a variety of tissues. In some animal models, ACAT inhibitors have antiatherosclerotic effects. METHODS We performed intravascular ultrasonography in 408 patients with angiographically documented coronary disease. All patients received usual care for secondary prevention, including statins, if indicated. Patients were randomly assigned to receive the ACAT inhibitor pactimibe (100 mg per day) or matching placebo. Ultrasonography was repeated after 18 months to measure the progression of atherosclerosis. RESULTS The primary efficacy variable analyzing the progression of atherosclerosis--the change in percent atheroma volume--was similar in the pactimibe and placebo groups (0.69 percent and 0.59 percent, respectively; P=0.77). However, both secondary efficacy variables assessed by means of intravascular ultrasonography showed unfavorable effects of pactimibe treatment. As compared with baseline values, the normalized total atheroma volume showed significant regression in the placebo group (-5.6 mm3, P=0.001) but not in the pactimibe group (-1.3 mm3, P=0.39; P=0.03 for the comparison between groups). The atheroma volume in the most diseased 10-mm subsegment regressed by 3.2 mm3 in the placebo group, as compared with a decrease of 1.3 mm3 in the pactimibe group (P=0.01). The combined incidence of adverse cardiovascular outcomes was similar in the two groups (P=0.53). CONCLUSIONS For patients with coronary disease, treatment with an ACAT inhibitor did not improve the primary efficacy variable (percent atheroma volume) and adversely affected two major secondary efficacy measures assessed by intravascular ultrasonography. ACAT inhibition is not an effective strategy for limiting atherosclerosis and may promote atherogenesis. (ClinicalTrials.gov number, NCT00268515.).
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Affiliation(s)
- Steven E Nissen
- Department of Cardiovascular Medicine, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
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He X, Lu Y, Saha N, Yang H, Heng CK. Acyl-CoA: cholesterol acyltransferase-2 gene polymorphisms and their association with plasma lipids and coronary artery disease risks. Hum Genet 2005; 118:393-403. [PMID: 16195894 DOI: 10.1007/s00439-005-0055-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2005] [Accepted: 08/09/2005] [Indexed: 10/25/2022]
Abstract
Acyl-CoA: cholesterol acyltransferase-2 (ACAT2), an intracellular cholesterol esterification enzyme found only in the intestine and liver, has been demonstrated to be associated with hypercholesterolemia and atherosclerosis in mice. To explore the possible impact of ACAT2 gene variants on CAD susceptibility and plasma lipid levels, three polymorphisms, 41A>G (Glu>Gly), 734C>T (Thr>Ile), and IVS4-57_58 ins48 bp (D/I), were genotyped in 809 CAD patients (CAD+) and 1,304 controls (CAD-) from three distinct Singaporean ethnic groups (1,228 Chinese, 367 Malays and 518 Indians). The 734T allele frequency was significantly lower in CAD+ (0.20) than CAD- (0.26) in Chinese (P=0.003) and I allele of D/I was significantly higher in CAD+ (0.17) than CAD- (0.10) in Indians (P=0.011). The 41G allele was significantly more frequent among normolipidemic (0.19) than dyslipidemic (0.13) individuals in Chinese (P=0.008). In normolipidemic females, 734C>T was associated with apoA1, apoB and lipoprotein (a) in Indians, and with apoA1 in Malays, whereas 41A>G is associated with total cholesterol in Indians. The 734C>T polymorphism was in almost complete linkage disequilibrium (LD) with the IVS4-57_58 ins48 bp and in very strong LD with 41A>G in all the three ethnic groups. In the normolipidemic females, the AG/CT had much higher apoB than AA/CC in Indians. We found that the three ACAT2 polymorphisms studied are associated with CAD risk and plasma lipid levels but their effects are not consistent across genders and ethnic groups.
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Affiliation(s)
- Xuelian He
- Department of Paediatrics, National University of Singapore, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
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Abe N, Osanai T, Fujiwara T, Kameda K, Matsunaga T, Okumura K. C-reactive protein-induced upregulation of extracellular matrix metalloproteinase inducer in macrophages: inhibitory effect of fluvastatin. Life Sci 2005; 78:1021-8. [PMID: 16182316 DOI: 10.1016/j.lfs.2005.06.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2005] [Accepted: 06/09/2005] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase (MMP)-9 were reported to be expressed at the macrophage-rich area in human coronary atherosclerotic plaque. We examined whether C-reactive protein (CRP) activates macrophages to express EMMPRIN and MMP-9 in vitro and whether statins inhibit it. METHODS AND RESULTS Rat peritoneal macrophages were collected by peritoneal lavage, and were incubated in the presence or absence of CRP. CRP at 5 microg/ml increased the gene expression of EMMPRIN relative to GAPDH, measured by RT-PCR, by 1.67+/-0.07 fold at 24 h and by 1.85+/-0.49 fold at 48 h (both p<0.05). The gene expression of MMP-9 in the presence of CRP at 5 microg/ml was followed by 1.36+/-0.11 fold increase at 24 h and by 3.95+/-0.81 fold at 48 h (both p<0.05). CRP at 5 microg/ml for 48 h increased by 6 fold MMP-9 activity, measured by zymography, without affecting tissue inhibitor of metalloproteinases-1. Boiled CRP at 5 mug/ml for 48 h unaffected MMP-9 activity. Fluvastatin blocked the CRP-induced increases in EMMPRIN and MMP-9 expression and activity. Diphenylene iodonium, an inhibitor of NADPH oxidase, had a similar effect on MMP-9 activity. Fluvastatin suppressed the CRP-induced increases in 8-epi-prostaglandin F(2alpha) levels in the condition media. CONCLUSIONS CRP is an activator for macrophages to enhance EMMPRIN and MMP-9 expression. Fluvastatin inhibits them presumably through its antioxidant effect.
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Affiliation(s)
- Naoki Abe
- Second Department of Internal Medicine, Hirosaki University School of Medicine 5 Zaifu, Hirosaki, Aomori, Japan
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Yoon YW, Kwon HM, Hwang KC, Choi EY, Hong BK, Kim D, Kim HS, Cho SH, Song KS, Sangiorgi G. Upstream regulation of matrix metalloproteinase by EMMPRIN; extracellular matrix metalloproteinase inducer in advanced atherosclerotic plaque. Atherosclerosis 2005; 180:37-44. [PMID: 15823273 DOI: 10.1016/j.atherosclerosis.2004.11.021] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2004] [Revised: 09/19/2004] [Accepted: 11/19/2004] [Indexed: 11/19/2022]
Abstract
From experimental and clinical studies it is known that matrix conservation and degradation by matrix metalloproteinases (MMPs) plays a major role in plaque progression and destabilization with related onset of acute vascular events such as acute coronary syndromes or cerebrovascular accidents. Recently, extracellular MMPs inducer (EMMPRIN) has been reported to induce and activate the expression of MMPs in myocardium and plays an important role in the ventricular remodeling in human heart failure. Similarly to heart failure myocardium, EMMPRIN may be expressed in human atheroma and play a role in the extracellular matrix (ECM) remodeling and atherogenic cell differentiation. This study was designed to investigate the possible biological role of EMMPRIN in human atheroma. Immunohistochemical analysis for MMPs and EMMPRIN was performed on human carotid endarterectomy specimens and control aortas. EMMPRIN showed significant immunoreactivity in human atherosclerotic carotid lesions, and was colocalized with macrophage/monocyte infiltrates in atherosclerotic intima, plaque itself and vascular smooth muscle cells (VSMCs). Zymography and Western blot analysis revealed EMMPRIN expression in the carotid atheromas, but not in the control aortas. Human bone marrow monocytes, which were cultured with atherogenic proinflammatory cytokine stimulation revealed increased EMMPRIN and MMPs expressions. ECM remodeling is under the control of induction and inhibition of matrix degrading protease and the novel MMP inducer, EMMPRIN may play a role in influx and differentiation of monocytes and destabilizing atheroma.
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Affiliation(s)
- Young Won Yoon
- Department of Internal Medicine and Cardiovascular Division, YongDong Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
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Lijnen HR. Metalloproteinases in Development and Progression of Vascular Disease. PATHOPHYSIOLOGY OF HAEMOSTASIS AND THROMBOSIS 2005; 33:275-81. [PMID: 15692229 DOI: 10.1159/000083814] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Remodeling of the vascular wall plays a role in many physiological processes, but also in the pathogenesis of major cardiovascular diseases such as restenosis and atherosclerosis. Remodeling requires proteolytic activity to degrade components of the extracellular matrix; this can be generated by the matrix metalloproteinase(MMP) system alone or in concert with the fibrinolytic (plasminogen/plasmin) system. Several lines of evidence suggest that the MMP system plays a role in vascular smooth muscle cell migration and neointima formation after vascular injury. In atherosclerotic lesions, active MMPs may contribute to plaque destabilisation by degrading extracellular matrix components, but may also promote aneurysm formation by proteolytic degradation of the elastic lamina. The MMP system may therefore represent a potential therapeutic target for treatment of restenosis or atherosclerosis.
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Affiliation(s)
- H Roger Lijnen
- Center for Molecular and Vascular Biology, KU Leuven, Belgium.
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Aikawa M, Libby P. The vulnerable atherosclerotic plaque: pathogenesis and therapeutic approach. Cardiovasc Pathol 2004; 13:125-38. [PMID: 15081469 DOI: 10.1016/s1054-8807(04)00004-3] [Citation(s) in RCA: 172] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2004] [Accepted: 01/08/2004] [Indexed: 12/23/2022] Open
Affiliation(s)
- Masanori Aikawa
- Donald W. Reynolds Cardiovascular Clinical Research Centers, Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
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Hiatt WR, Klepack E, Nehler M, Regensteiner JG, Blue J, Imus J, Criqui MH. The effect of inhibition of acyl coenzyme A-cholesterol acyltransferase (ACAT) on exercise performance in patients with peripheral arterial disease. Vasc Med 2004; 9:271-7. [PMID: 15678619 DOI: 10.1191/1358863x04vm569oa] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This study tested the hypothesis that avasimibe, an inhibitor of acyl coenzyme A-cholesterol acyltransferase (ACAT), would improve treadmill exercise performance in patients with claudication secondary to peripheral arterial disease (PAD). Four hundred and forty-two patients with PAD (ankle-brachial index in the index leg of < or =0.90 with a > or =20% reduction post-exercise) were enrolled from 39 centers in the USA. Patients were randomized to receive oral avasimibe 50 mg, 250 mg, 750 mg or placebo for a treatment period of 12 months. Changes from baseline in peak walking time (PWT) using a graded treadmill protocol were compared among groups after 6 and 12 months of treatment. Individual group comparisons were considered statistically significant if p < 0.0245 for the 50 mg and 250 mg groups and p < 0.001 for the 750 mg group. Patients randomized to the 50 mg group experienced a 0.76 min net increase over placebo in PWT, but this did not reach the pre-specified level of statistical significance (Hochberg procedure p = 0.027) using ANCOVA after 12 months of treatment after adjusting for multiple comparisons. This trend in PWT was supported by the changes in treadmill initial claudication time (ICT) (p = 0.026) and Walking Impairment Questionnaire (WIQ) walking distance score (p = 0.058). The 250 mg and 750 mg avasimibe dose groups failed to demonstrate an improvement in PWT over placebo after 6 months of treatment. In conclusion, while the ACAT inhibitor avasimibe did not show clear evidence of benefit on treadmill exercise performance in patients with PAD, the results add to our knowledge of the impact of treatments directed at atherosclerosis on functional endpoints.
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Affiliation(s)
- William R Hiatt
- Section of Vascular Medicine, University of Colorado Health Sciences Center, 4200 E 9th Ave, Denver, CO 80262, USA.
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