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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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2
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Li D, Liu Q, Lu X, Li Z, Wang C, Leung CH, Wang Y, Peng C, Lin L. α-Mangostin remodels visceral adipose tissue inflammation to ameliorate age-related metabolic disorders in mice. Aging (Albany NY) 2019; 11:11084-11110. [PMID: 31806859 PMCID: PMC6932911 DOI: 10.18632/aging.102512] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 11/18/2019] [Indexed: 12/12/2022]
Abstract
Low-grade chronic adipose tissue inflammation contributes to the onset and development of aging-related insulin resistance and type 2 diabetes. In the current study, α-mangostin, a xanthone isolated from mangosteen (Garcinia mangostana), was identified to ameliorate lipopolysaccharides-induced acute adipose tissue inflammation in mice, by reducing the expression of pro-inflammatory cytokines and chemokines. In a cohort of young (3 months) and old (18-20 months) mice, α-mangostin mitigated aging-associated adiposity, hyperlipidemia, and insulin resistance. Further study showed that α-mangostin alleviated aging-related adipose tissue inflammation by reducing macrophage content and shifting pro-inflammatory macrophage polarization. Moreover, α-mangostin protected the old mice against liver injury through suppressing the secretion of microRNA-155-5p from macrophages. The above results demonstrated that α-mangostin represents a new scaffold to alleviate adipose tissue inflammation, which might be a novel candidate to treat aging-related metabolic disorders.
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Affiliation(s)
- Dan Li
- State Key Laboratory of Southwestern Characteristic Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China.,State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau, China
| | - Qianyu Liu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau, China
| | - Xiuqiang Lu
- Fuqing Branch of Fujian Normal University, Fuzhou, China
| | - Zhengqiu Li
- School of Pharmacy, Jinan University, Guangzhou, China
| | - Chunming Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau, China
| | - Chung-Hang Leung
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau, China
| | - Yitao Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau, China
| | - Cheng Peng
- State Key Laboratory of Southwestern Characteristic Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Ligen Lin
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau, China.,State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
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3
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Kamoshita S, Murata M, Koyama D, Julamanee J, Okuno S, Takagi E, Miyao K, Goto T, Ozawa Y, Miyamura K, Terakura S, Nishida T, Kiyoi H. Donor single nucleotide polymorphism in ACAT1 affects the incidence of graft-versus-host disease after bone marrow transplantation. Int J Hematol 2019; 111:112-119. [PMID: 31559562 DOI: 10.1007/s12185-019-02739-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 09/17/2019] [Accepted: 09/17/2019] [Indexed: 10/25/2022]
Abstract
Acyl-coenzyme A: cholesterol acyltransferase 1 (ACAT1) is an enzyme that converts cholesterol to cholesteryl esters. A recent in vivo study reported that inhibiting ACAT1 enzyme activity upregulates the membrane cholesterol levels of T cells, enhancing their cytotoxic function. In the present study, we investigated whether the presence of the ACAT1 single nucleotide polymorphism rs11545566 in transplant donors affected the risk of graft-versus-host disease (GVHD) in 116 adult patients who underwent bone marrow transplantation from human leukocyte antigen-identical sibling donors, and who received GVHD prophylaxis with short-term methotrexate and cyclosporine. The frequencies of the AA, AG, and GG genotypes in the donors were 31%, 45%, and 24%, respectively. The cumulative incidences of grade II-IV acute GVHD on day 100 in patients whose donors had AA vs. non-AA genotypes were 6% and 18%, respectively, and those of extensive chronic GVHD at 2 years were 7% and 32%, respectively. Multivariate analyses demonstrated that donor rs11545566 non-AA genotypes showed a trend toward a higher incidence of grade II-IV acute GVHD (P = 0.079), and were significantly associated with a higher incidence of extensive chronic GVHD (P = 0.021). These results suggest that donor ACAT1 rs11545566 genotype may be predictive of GVHD.
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Affiliation(s)
- Sonoko Kamoshita
- Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, Aichi, 466-8550, Japan
| | - Makoto Murata
- Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, Aichi, 466-8550, Japan.
| | - Daisuke Koyama
- Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, Aichi, 466-8550, Japan
| | - Jakrawadee Julamanee
- Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, Aichi, 466-8550, Japan
| | - Shingo Okuno
- Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, Aichi, 466-8550, Japan
| | - Erina Takagi
- Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, Aichi, 466-8550, Japan
| | - Kotaro Miyao
- Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, Aichi, 466-8550, Japan
| | - Tatsunori Goto
- Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, Aichi, 466-8550, Japan.,Department of Hematology, Japanese Red Cross Nagoya First Hospital, Nagoya, Japan
| | - Yukiyasu Ozawa
- Department of Hematology, Japanese Red Cross Nagoya First Hospital, Nagoya, Japan
| | - Koichi Miyamura
- Department of Hematology, Japanese Red Cross Nagoya First Hospital, Nagoya, Japan
| | - Seitaro Terakura
- Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, Aichi, 466-8550, Japan
| | - Tetsuya Nishida
- Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, Aichi, 466-8550, Japan
| | - Hitoshi Kiyoi
- Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, Aichi, 466-8550, Japan
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4
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Kim J, Thompson B, Han S, Lotan Y, McDonald JG, Ye J. Uptake of HDL-cholesterol contributes to lipid accumulation in clear cell renal cell carcinoma. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:158525. [PMID: 31513923 DOI: 10.1016/j.bbalip.2019.158525] [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] [Received: 07/17/2019] [Revised: 09/03/2019] [Accepted: 09/05/2019] [Indexed: 01/06/2023]
Abstract
Clear cell renal cell carcinoma (ccRCC), which accounts for the majority of kidney cancer, is known to accumulate excess cholesterol. However, the mechanism and functional significance of the lipid accumulation for development of the cancer remains obscure. In this study, we analyzed 42 primary ccRCC samples, and determined that cholesterol levels of ~ 70% of the tumors were at least two-fold higher than that of benign kidney tissues. Compared to tumors without cholesterol accumulation, those containing excess cholesterol expressed higher levels of scavenger receptor BI (SR-B1), a receptor for uptake of HDL-associated cholesterol, but not genes involved in cholesterol synthesis and uptake of LDL-associated cholesterol. To further determine the roles of sterol accumulation for cancer development, we implanted ccRCC from patients into mouse kidneys using a mouse ccRCC xenograft model. Feeding mice with probucol, a compound lowing HDL-cholesterol, markedly reduced levels of cholesterol in tumors containing excess cholesterol. This treatment, however, did not affect growth of these tumors. Our study suggests that cholesterol overaccumulation in ccRCC is the consequence of increased uptake of HDL-cholesterol as a result of SR-B1 overexpression, but the lipid accumulation by itself may not play a significant role in progression of the cancer.
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Affiliation(s)
- JungYeon Kim
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Bonne Thompson
- Center for Human Nutrition, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Sungwon Han
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Yair Lotan
- Department of Urology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Jeffrey G McDonald
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA; Center for Human Nutrition, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Jin Ye
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
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5
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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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6
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Huang LH, Melton EM, Li H, Sohn P, Jung D, Tsai CY, Ma T, Sano H, Ha H, Friedline RH, Kim JK, Usherwood E, Chang CCY, Chang TY. Myeloid-specific Acat1 ablation attenuates inflammatory responses in macrophages, improves insulin sensitivity, and suppresses diet-induced obesity. Am J Physiol Endocrinol Metab 2018; 315. [PMID: 29533741 PMCID: PMC6171008 DOI: 10.1152/ajpendo.00174.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Macrophages are phagocytes that play important roles in health and diseases. Acyl-CoA:cholesterol acyltransferase 1 (ACAT1) converts cellular cholesterol to cholesteryl esters and is expressed in many cell types. Unlike global Acat1 knockout (KO), myeloid-specific Acat1 KO ( Acat1-) does not cause overt abnormalities in mice. Here, we performed analyses in age- and sex-matched Acat1-M/-M and wild-type mice on chow or Western diet and discovered that Acat1-M/-M mice exhibit resistance to Western diet-induced obesity. On both chow and Western diets, Acat1-M/-M mice display decreased adipocyte size and increased insulin sensitivity. When fed with Western diet, Acat1-M/-M mice contain fewer infiltrating macrophages in white adipose tissue (WAT), with significantly diminished inflammatory phenotype. Without Acat1, the Ly6Chi monocytes express reduced levels of integrin-β1, which plays a key role in the interaction between monocytes and the inflamed endothelium. Adoptive transfer experiment showed that the appearance of leukocytes from Acat1-M/-M mice to the inflamed WAT of wild-type mice is significantly diminished. Under Western diet, Acat1-M/-M causes suppression of multiple proinflammatory genes in WAT. Cell culture experiments show that in RAW 264.7 macrophages, inhibiting ACAT1 with a small-molecule ACAT1-specific inhibitor reduces inflammatory responses to lipopolysaccharide. We conclude that under Western diet, blocking ACAT1 in macrophages attenuates inflammation in WAT. Other results show that Acat1-M/-M does not compromise antiviral immune response. Our work reveals that blocking ACAT1 suppresses diet-induced obesity in part by slowing down monocyte infiltration to WAT as well as by reducing the inflammatory responses of adipose tissue macrophages.
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Affiliation(s)
- Li-Hao Huang
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - Elaina M Melton
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - Haibo Li
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - Paul Sohn
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - DaeYoung Jung
- Program in Molecular Medicine, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Ching-Yi Tsai
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire
| | - Tian Ma
- Department of Pharmacology and Toxicology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - Hiroyuki Sano
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - HyeKyung Ha
- Program in Molecular Medicine, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Randall H Friedline
- Program in Molecular Medicine, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Jason K Kim
- Program in Molecular Medicine, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Edward Usherwood
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire
| | - Catherine C Y Chang
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - Ta-Yuan Chang
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
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7
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Wang XQ, Wan HQ, Wei XJ, Zhang Y, Qu P. CLI-095 decreases atherosclerosis by modulating foam cell formation in apolipoprotein E-deficient mice. Mol Med Rep 2016; 14:49-56. [PMID: 27176130 PMCID: PMC4918599 DOI: 10.3892/mmr.2016.5233] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 12/18/2015] [Indexed: 12/13/2022] Open
Abstract
Toll-like receptor 4 (TLR4) is considered to have a critical role in the occurrence and development of atherosclerosis in atherosclerosis-prone mice; however, it remains uncertain whether treatment with a TLR4 inhibitor may attenuate atherosclerosis. The present study aimed to determine the vascular protective effects of the TLR4 inhibitor CLI-095 on apolipoprotein E‑deficient (ApoE‑/‑) mice. ApoE‑/‑ mice were fed either chow or a high‑fat diet, and were treated with or without CLI‑095 for 10 weeks. The mean atherosclerotic plaque area in the aortic sections of CLI‑095‑treated mice was 54.3% smaller than in the vehicle‑treated mice (P=0.0051). In vitro, murine peritoneal macrophages were treated with or without CLI‑095, and were subsequently stimulated with oxidized low‑density lipoprotein. Treatment with CLI‑095 markedly reduced the expression levels of lectin‑like oxidized low‑density lipoprotein receptor‑1 and acyl-coenzyme A:cholesterol acyltransferase‑1, and significantly upregulated the expression levels of ATP‑binding cassette transporter A1, predominantly via suppressing activation of the TLR4/nuclear factor‑κB signaling pathway. The results of the present study indicated that the TLR4 inhibitor CLI‑095 has the ability to suppress the progression of atherosclerosis in an in vivo model by reducing macrophage foam cell formation.
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Affiliation(s)
- Xiao-Qing Wang
- Department of Cardiology, Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116023, P.R. China
| | - Hui-Qing Wan
- Department of Pharmacy, Dongguan People's Hospital, Dongguan, Guangdong 523000, P.R. China
| | - Xian-Jing Wei
- Department of Cardiology, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning 116023, P.R. China
| | - Ying Zhang
- Department of Cardiology, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning 116023, P.R. China
| | - Peng Qu
- Department of Cardiology, Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116023, P.R. China
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8
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Affiliation(s)
- Hong Lu
- From the Saha Cardiovascular Research Center, University of Kentucky, Lexington.
| | - Alan Daugherty
- From the Saha Cardiovascular Research Center, University of Kentucky, Lexington
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9
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Huang LH, Melton EM, Li H, Sohn P, Rogers MA, Mulligan-Kehoe MJ, Fiering SN, Hickey WF, Chang CCY, Chang TY. Myeloid Acyl-CoA:Cholesterol Acyltransferase 1 Deficiency Reduces Lesion Macrophage Content and Suppresses Atherosclerosis Progression. J Biol Chem 2016; 291:6232-44. [PMID: 26801614 DOI: 10.1074/jbc.m116.713818] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Indexed: 01/03/2023] Open
Abstract
Acyl-CoA:cholesterol acyltransferase 1 (Acat1) converts cellular cholesterol to cholesteryl esters and is considered a drug target for treating atherosclerosis. However, in mouse models for atherosclerosis, global Acat1 knockout (Acat1(-/-)) did not prevent lesion development. Acat1(-/-) increased apoptosis within lesions and led to several additional undesirable phenotypes, including hair loss, dry eye, leukocytosis, xanthomatosis, and a reduced life span. To determine the roles of Acat1 in monocytes/macrophages in atherosclerosis, we produced a myeloid-specific Acat1 knockout (Acat1(-M/-M)) mouse and showed that, in the Apoe knockout (Apoe(-/-)) mouse model for atherosclerosis, Acat1(-M/-M) decreased the plaque area and reduced lesion size without causing leukocytosis, dry eye, hair loss, or a reduced life span. Acat1(-M/-M) enhanced xanthomatosis in apoe(-/-) mice, a skin disease that is not associated with diet-induced atherosclerosis in humans. Analyses of atherosclerotic lesions showed that Acat1(-M/-M) reduced macrophage numbers and diminished the cholesterol and cholesteryl ester load without causing detectable apoptotic cell death. Leukocyte migration analysis in vivo showed that Acat1(-M/-M) caused much fewer leukocytes to appear at the activated endothelium. Studies in inflammatory (Ly6C(hi)-positive) monocytes and in cultured macrophages showed that inhibiting ACAT1 by gene knockout or by pharmacological inhibition caused a significant decrease in integrin β 1 (CD29) expression in activated monocytes/macrophages. The sparse presence of lesion macrophages without Acat1 can therefore, in part, be attributed to decreased interaction between inflammatory monocytes/macrophages lacking Acat1 and the activated endothelium. We conclude that targeting ACAT1 in a myeloid cell lineage suppresses atherosclerosis progression while avoiding many of the undesirable side effects caused by global Acat1 inhibition.
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Affiliation(s)
- Li-Hao Huang
- From the Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755 and
| | - Elaina M Melton
- From the Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755 and
| | - Haibo Li
- From the Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755 and
| | - Paul Sohn
- From the Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755 and
| | - Maximillian A Rogers
- From the Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755 and
| | | | | | - William F Hickey
- Pathology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire 03756
| | - Catherine C Y Chang
- From the Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755 and
| | - Ta-Yuan Chang
- From the Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755 and
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10
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Abstract
Alzheimer's disease (AD) is the most common cause of dementia with no cure at present. Cholesterol metabolism is closely associated with AD at several stages. ACAT1 converts free cholesterol to cholesteryl esters, and plays important roles in cellular cholesterol homeostasis. Recent studies show that in a mouse model, blocking ACAT1 provides multiple beneficial effects on AD. Here we review the current evidence that implicates ACAT1 as a therapeutic target for AD. We also discuss the potential usage of various ACAT inhibitors currently available to treat AD.
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11
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Ohmoto T, Nishitsuji K, Yoshitani N, Mizuguchi M, Yanagisawa Y, Saito H, Sakashita N. K604, a specific acyl‑CoA:cholesterol acyltransferase 1 inhibitor, suppresses proliferation of U251‑MG glioblastoma cells. Mol Med Rep 2015; 12:6037-42. [PMID: 26252415 DOI: 10.3892/mmr.2015.4200] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 07/23/2015] [Indexed: 11/06/2022] Open
Abstract
Glioblastoma is the most aggressive type of brain tumor and has a poor prognosis. Increased levels of cholesteryl ester and simultaneous expression of acyl‑CoA:cholesterol acyltransferase 1 (ACAT1) in tumor cells indicated that cholesterol esterification is critical to tumor growth. The present study confirmed that human glioblastoma tissues as well as the glioblastoma cell line U251‑MG showed significant expression of ACAT1. ACAT1 expression in U251‑MG cells increased in a cell proliferation‑dependent manner. K604, a selective ACAT1 inhibitor, suppressed the proliferation of U251‑MG cells and downregulated the activation of Akt and extracellular signal‑regulated kinase in proliferating glioblastoma cells. These results suggested that ACAT1 may be a therapeutic target for the treatment of glioblastoma, with K604 as an effective therapeutic agent.
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Affiliation(s)
- Takuji Ohmoto
- Department of Human Pathology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770‑8503, Japan
| | - Kazuchika Nishitsuji
- Department of Human Pathology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770‑8503, Japan
| | - Nobuyuki Yoshitani
- Department of Human Pathology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770‑8503, Japan
| | - Makoto Mizuguchi
- Department of Human Pathology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770‑8503, Japan
| | - Yuto Yanagisawa
- Department of Physical Pharmaceutics, Institute of Health Biosciences and Graduate School of Pharmaceutical Sciences, The University of Tokushima, Tokushima 770‑8505, Japan
| | - Hiroyuki Saito
- Department of Physical Pharmaceutics, Institute of Health Biosciences and Graduate School of Pharmaceutical Sciences, The University of Tokushima, Tokushima 770‑8505, Japan
| | - Naomi Sakashita
- Department of Human Pathology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770‑8503, Japan
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12
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Stansfield BK, Ingram DA. Clinical significance of monocyte heterogeneity. Clin Transl Med 2015; 4:5. [PMID: 25852821 PMCID: PMC4384980 DOI: 10.1186/s40169-014-0040-3] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 10/29/2014] [Indexed: 12/14/2022] Open
Abstract
Monocytes are primitive hematopoietic cells that primarily arise from the bone marrow, circulate in the peripheral blood and give rise to differentiated macrophages. Over the past two decades, considerable attention to monocyte diversity and macrophage polarization has provided contextual clues into the role of myelomonocytic derivatives in human disease. Until recently, human monocytes were subdivided based on expression of the surface marker CD16. "Classical" monocytes express surface markers denoted as CD14(++)CD16(-) and account for greater than 70% of total monocyte count, while "non-classical" monocytes express the CD16 antigen with low CD14 expression (CD14(+)CD16(++)). However, recognition of an intermediate population identified as CD14(++)CD16(+) supports the new paradigm that monocytes are a true heterogeneous population and careful identification of specific subpopulations is necessary for understanding monocyte function in human disease. Comparative studies of monocytes in mice have yielded more dichotomous results based on expression of the Ly6C antigen. In this review, we will discuss the use of monocyte subpopulations as biomarkers of human disease and summarize correlative studies in mice that may yield significant insight into the contribution of each subset to disease pathogenesis.
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Affiliation(s)
- Brian K Stansfield
- Department of Pediatrics and Neonatal-Perinatal Medicine, Georgia Regents University, Augusta, Georgia ; Vascular Biology Center, Georgia Regents University, Augusta, Georgia ; Medical College of Georgia at Georgia Regents University, 1120 15th St, BIW-6033, Augusta, GA 30912 USA
| | - David A Ingram
- Herman B. Wells Center for Pediatric Research, Georgia Regents University, Augusta, Georgia ; Department of Pediatrics and Neonatal-Perinatal Medicine, Indiana University School of Medicine, Indianapolis, Indiana USA ; Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 699 Riley Hospital Drive, RR208, Indianapolis, IN 46202 USA
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Zhang H, Temel RE, Martel C. Cholesterol and lipoprotein metabolism: Early Career Committee contribution. Arterioscler Thromb Vasc Biol 2014; 34:1791-4. [PMID: 25142876 DOI: 10.1161/atvbaha.114.304267] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Hanrui Zhang
- From the Department of Medicine, Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia (H.Z.); Department of Pharmacology and Nutritional Sciences, Saha Cardiovascular Research Center, University of Kentucky, Lexington (R.E.T.); and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (C.M.).
| | - Ryan E Temel
- From the Department of Medicine, Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia (H.Z.); Department of Pharmacology and Nutritional Sciences, Saha Cardiovascular Research Center, University of Kentucky, Lexington (R.E.T.); and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (C.M.)
| | - Catherine Martel
- From the Department of Medicine, Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia (H.Z.); Department of Pharmacology and Nutritional Sciences, Saha Cardiovascular Research Center, University of Kentucky, Lexington (R.E.T.); and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (C.M.)
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Abstract
A series of studies has been presented in the search for proof of circulating and resident vascular progenitor cells, which can differentiate into endothelial and smooth muscle cells and pericytes in animal and human studies. In terms of pluripotent stem cells, including embryonic stem cells, iPS, and partial-iPS cells, they display a great potential for vascular lineage differentiation. Development of stem cell therapy for treatment of vascular and ischemic diseases remains a major challenging research field. At the present, there is a clear expansion of research into mechanisms of stem cell differentiation into vascular lineages that are tested in animal models. Although there are several clinical trials ongoing that primarily focus on determining the benefits of stem cell transplantation in ischemic heart or peripheral ischemic tissues, intensive investigation for translational aspects of stem cell therapy would be needed. It is a hope that stem cell therapy for vascular diseases could be developed for clinic application in the future.
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Affiliation(s)
- Li Zhang
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z.); and Department of Cardiology, Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (Q.X.)
| | - Qingbo Xu
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z.); and Department of Cardiology, Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (Q.X.).
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Huang LH, Nishi K, Li S, Ho T, Dong R, Chang CCY, Chang TY. Acyl-coenzyme A:cholesterol acyltransferase 1 - significance of single-nucleotide polymorphism at residue 526 and the role of Pro347 near the fifth transmembrane domain. FEBS J 2014; 281:1773-83. [PMID: 24517390 DOI: 10.1111/febs.12739] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 01/10/2014] [Accepted: 01/30/2014] [Indexed: 11/28/2022]
Abstract
Acyl-coenzyme A:cholesterol acyltransferases (ACATs), which are members of the membrane-bound O-acyltransferase family, catalyze the conversion of cholesterol to cholesteryl esters. Mammals have two isoenzymes: ACAT1 and ACAT2. Both enzymes are drug targets for treating human diseases. ACAT1 is present in various cell types. It contains nine transmembrane domains (TMDs), with the active site His460 located within TMD7, and the active site Asn421 located within the fourth large cytoplasmic loop. In human ACAT1, a single-nucleotide polymorphism exists for residue 526: the codon is either CAG for Gln, or CGG for Arg. Gln526/Arg526 is present within the C-terminal loop. Its biochemical significance is unknown. In addition, within the C-terminal half of ACAT1, numerous residues conserved with those of ACAT2 are present; the functions of these conserved residues are largely unknown. Here, we performed single-substitution mutagenesis experiments to investigate the roles of individual residues present in the C-terminal loop, including Gln526/Arg526, and the eight conserved Pro residues located near/in various TMDs. The results show that the enzyme activity of ACAT1 with Gln526 is less active than that of ACAT1 with Arg526 by 40%. In addition, several residues in the C-terminal loop are important for maintaining proper ACAT1 protein stability. Other results show that Pro347 plays an important role in modulating enzyme catalysis. Overall, our results imply that the CAG/CGG polymorphism can be utilized to perform ACAT1 activity/human disease susceptibility studies, and that Pro347 located near TMD5 plays an important role in modulating enzyme catalysis.
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Affiliation(s)
- Li-Hao Huang
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
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