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Steck TL, Lange Y. Is reverse cholesterol transport regulated by active cholesterol? J Lipid Res 2023; 64:100385. [PMID: 37169287 PMCID: PMC10279919 DOI: 10.1016/j.jlr.2023.100385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 05/02/2023] [Accepted: 05/05/2023] [Indexed: 05/13/2023] Open
Abstract
This review considers the hypothesis that a small portion of plasma membrane cholesterol regulates reverse cholesterol transport in coordination with overall cellular homeostasis. It appears that almost all of the plasma membrane cholesterol is held in stoichiometric complexes with bilayer phospholipids. The minor fraction of cholesterol that exceeds the complexation capacity of the phospholipids is called active cholesterol. It has an elevated chemical activity and circulates among the organelles. It also moves down its chemical activity gradient to plasma HDL, facilitated by the activity of ABCA1, ABCG1, and SR-BI. ABCA1 initiates this process by perturbing the organization of the plasma membrane bilayer, thereby priming its phospholipids for translocation to apoA-I to form nascent HDL. The active excess sterol and that activated by ABCA1 itself follow the phospholipids to the nascent HDL. ABCG1 similarly rearranges the bilayer and sends additional active cholesterol to nascent HDL, while SR-BI simply facilitates the equilibration of the active sterol between plasma membranes and plasma proteins. Active cholesterol also flows downhill to cytoplasmic membranes where it serves both as a feedback signal to homeostatic ER proteins and as the substrate for the synthesis of mitochondrial 27-hydroxycholesterol (27HC). 27HC binds the LXR and promotes the expression of the aforementioned transport proteins. 27HC-LXR also activates ABCA1 by competitively displacing its inhibitor, unliganded LXR. § Considerable indirect evidence suggests that active cholesterol serves as both a substrate and a feedback signal for reverse cholesterol transport. Direct tests of this novel hypothesis are proposed.
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Affiliation(s)
- Theodore L Steck
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Yvonne Lange
- Department of Pathology, Rush University Medical Center, Chicago, IL, USA.
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2
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Bian Y, Alem D, Beato F, Hogenson TL, Yang X, Jiang K, Cai J, Ma WW, Fernandez-Zapico M, Tan AC, Lawrence NJ, Fleming JB, Yuan Y, Xie H. Development of SOS1 Inhibitor-Based Degraders to Target KRAS-Mutant Colorectal Cancer. J Med Chem 2022; 65:16432-16450. [PMID: 36459180 PMCID: PMC10113742 DOI: 10.1021/acs.jmedchem.2c01300] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Direct blockade of KRAS driver mutations in colorectal cancer (CRC) has been challenging. Targeting SOS1, a guanine nucleotide exchange factor, has arisen as an attractive approach for KRAS-mutant CRC. Here, we describe the development of novel SOS1 degraders and their activity in patient-derived CRC organoids (PDO). The design of these degraders as proteolysis-targeting chimera was based on the crystal structures of cereblon and SOS1. The synthesis used the 6- and 7-OH groups of a quinazoline core as anchor points to connect lenalidomide. Fifteen compounds were screened for SOS1 degradation. P7 was found to have up to 92% SOS1 degradation in both CRC cell lines and PDOs with excellent specificity. SOS1 degrader P7 demonstrated superior activity in inhibiting CRC PDO growth with an IC50 5 times lower than that of SOS1 inhibitor BI3406. In summary, we developed new SOS1 degraders and demonstrated SOS1 degradation as a feasible therapeutic strategy for KRAS-mutant CRC.
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Affiliation(s)
- Yujia Bian
- Department of Chemistry, University of Central Florida, 4111 Libra Drive, Orlando, Florida 32816, United States
| | - Diego Alem
- Department of Gastrointestinal Oncology, H Lee Moffitt Cancer Center and Research Institute, 12902 USF Magnolia Drive, Tampa, Florida 33612, United States
| | - Francisca Beato
- Department of Gastrointestinal Oncology, H Lee Moffitt Cancer Center and Research Institute, 12902 USF Magnolia Drive, Tampa, Florida 33612, United States
| | - Tara L Hogenson
- Schulze Center for Novel Therapeutics, Department of Oncology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, United States
| | - Xinrui Yang
- Department of Gastrointestinal Oncology, H Lee Moffitt Cancer Center and Research Institute, 12902 USF Magnolia Drive, Tampa, Florida 33612, United States
| | - Kun Jiang
- Department of Pathology, H Lee Moffitt Cancer Center and Research Institute, 12902 USF Magnolia Drive, Tampa, Florida 33612, United States
| | - Jianfeng Cai
- Department of Chemistry, University of South Florida, 12111 USF Sweetgum Ln, Tampa, Florida 33620, United States
| | - Wen Wee Ma
- Division of Medical Oncology, Department of Oncology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, United States
| | - Martin Fernandez-Zapico
- Schulze Center for Novel Therapeutics, Department of Oncology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, United States
| | - Aik Choon Tan
- Department of Biostatistics and Bioinformatics, H Lee Moffitt Cancer Center and Research Institute, 12902 USF Magnolia Drive, Tampa, Florida 33612, United States
| | - Nicholas J Lawrence
- Department of Drug Discovery, H Lee Moffitt Cancer Center and Research Institute, 12902 USF Magnolia Drive, Tampa, Florida 33612, United States
| | - Jason B Fleming
- Department of Gastrointestinal Oncology, H Lee Moffitt Cancer Center and Research Institute, 12902 USF Magnolia Drive, Tampa, Florida 33612, United States
| | - Yu Yuan
- Department of Chemistry, University of Central Florida, 4111 Libra Drive, Orlando, Florida 32816, United States
| | - Hao Xie
- Department of Gastrointestinal Oncology, H Lee Moffitt Cancer Center and Research Institute, 12902 USF Magnolia Drive, Tampa, Florida 33612, United States
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The circadian transcription factor ARNTL2 is regulated by weight-loss interventions in human white adipose tissue and inhibits adipogenesis. Cell Death Dis 2022; 8:443. [PMID: 36329012 PMCID: PMC9633602 DOI: 10.1038/s41420-022-01239-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/20/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022]
Abstract
Misalignment of physiological circadian rhythms promotes obesity which is characterized by white adipose tissue (WAT) expansion. Differentiation of Adipose stem/progenitor cells (ASCs) contributes to WAT increase but the importance of the cellular clock in this process is incompletely understood. In the present study, we reveal the role of the circadian transcription factor Aryl hydrocarbon receptor nuclear translocator-like 2 (ARNTL2) in human ASCs, isolated from subcutaneous (s)WAT samples of patients undergoing routine elective plastic abdominal surgery. We show that circadian synchronization by serum-shock or stimulation with adipogenic stimuli leads to a different expression pattern of ARNTL2 relative to its well-studied paralogue ARNTL1. We demonstrate that ARNTL2 mRNA is downregulated in ASCs upon weight-loss (WL) whereas ARNTL2 protein is rapidly induced in the course of adipogenic differentiation and highly abundant in adipocytes. ARNTL2 protein is maintained in ASCs cooperatively by mechanistic Target of Rapamycin (mTOR) and Mitogen-activated Protein Kinase (MAPK) signalling pathways while ARNTL2 functions as an inhibitor on both circuits, leading to a feedback mechanism. Consistently, ectopic overexpression of ARNTL2 repressed adipogenesis by facilitating the degradation of ARNTL1, inhibition of Kruppel-Like Factor 15 (KLF15) gene expression and down-regulation of the MAPK-CCAAT/enhancer-binding protein β (C/EBPβ) axis. Western blot analysis of sWAT samples from normal-weight, obese and WL donors revealed that ARNTL2 protein was solely elevated by WL compared to ARNTL1 which underscores unique functions of both transcription factors. In conclusion, our study reveals ARNTL2 to be a WL-regulated inhibitor of adipogenesis which might provide opportunities to develop strategies to ameliorate obesity.
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NGF Modulates Cholesterol Metabolism and Stimulates ApoE Secretion in Glial Cells Conferring Neuroprotection against Oxidative Stress. Int J Mol Sci 2022; 23:ijms23094842. [PMID: 35563230 PMCID: PMC9100774 DOI: 10.3390/ijms23094842] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 04/24/2022] [Accepted: 04/25/2022] [Indexed: 12/18/2022] Open
Abstract
Cholesterol plays a crucial role in the brain, where its metabolism is particularly regulated by astrocytic activity. Indeed, adult neurons suppress their own cholesterol biosynthesis and import this sterol through ApoE-rich particles secreted from astrocytes. Recent evidence suggests that nerve growth factor (NGF) may exert neurotrophic activity by influencing cell metabolism. Nevertheless, the effect of NGF on glial cholesterol homeostasis has still not been elucidated. Thus, the aim of this project is to assess whether NGF could influence cholesterol metabolism in glial cells. To reach this objective, the U373 astrocyte-derived cell line was used as an experimental model. Immunoblot and ELISA analysis showed that proteins and enzymes belonging to the cholesterol metabolism network were increased upon NGF treatment in glial cells. Furthermore, NGF significantly increased ApoE secretion and the amount of extracellular cholesterol in the culture medium. Co-culture and U373-conditioned medium experiments demonstrated that NGF treatment efficiently counteracted rotenone-mediated cytotoxicity in N1E-115 neuronal cells. Conversely, neuroprotection mediated by NGF treatment was suppressed when N1E-115 were co-cultured with ApoE-silenced U373 cells. Taken together, these data suggest that NGF controls cholesterol homeostasis in glial cells. More importantly, NGF exerts neuroprotection against oxidative stress, which is likely associated with the induction of glial ApoE secretion.
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Ahmadi A, Bagheri Ekta M, Sahebkar A. Mechanisms of antidiabetic drugs and cholesterol efflux: a clinical perspective. Drug Discov Today 2022; 27:1679-1688. [PMID: 35182734 DOI: 10.1016/j.drudis.2022.02.006] [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: 08/18/2021] [Revised: 01/09/2022] [Accepted: 02/14/2022] [Indexed: 11/26/2022]
Abstract
Reverse cholesterol transport (RCT) is a physiological process that reduces excess cholesterol in the body. Cholesterol efflux (CE), an important step in RCT, is mainly mediated by ATP-binding cassette transporters A1 and G1 and has a significant role in atheroprotection. Moreover, impairments in CE can lead to the development of diabetes and fatty liver disease. In this review, we summarize the possible effects of hypoglycemic agents on CE and how this might influence atherosclerosis and dyslipidemia-related pathologies. Newer antidiabetic agents could have significant potential for targeting CE and preventing or alleviating atherosclerosis, obesity, and liver steatosis, and simultaneously improving insulin secretion. However, more research is warranted to interpret the clinical relevance of these data.
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Affiliation(s)
- Ali Ahmadi
- School of Pharmacy, Mashhad University of Medical Sciences, Mashhad 9177948567, Iran
| | - Mariam Bagheri Ekta
- Laboratory of Cellular and Molecular Pathology of Cardiovascular System, A.P. Avtsyn Research Institute of Human Morphology, 3 Tsyurupy Street, 117418 Moscow, Russian Federation
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; School of Medicine, The University of Western Australia, Perth, WA, Australia; Department of Medical Biotechnology and Nanotechnology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Biotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
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Lyu J, Fukunaga K, Imachi H, Sato S, Kobayashi T, Saheki T, Ibata T, Yoshimura T, Iwama H, Murao K. Oxidized LDL Downregulates ABCA1 Expression via MEK/ERK/LXR Pathway in INS-1 Cells. Nutrients 2021; 13:nu13093017. [PMID: 34578896 PMCID: PMC8465850 DOI: 10.3390/nu13093017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 08/23/2021] [Accepted: 08/24/2021] [Indexed: 12/23/2022] Open
Abstract
Impaired insulin secretion is one of the main causes of type 2 diabetes. Cholesterol accumulation-induced lipotoxicity contributes to impaired insulin secretion in pancreatic beta cells. However, the detailed mechanism in this process remains unclear. In this study, we proved that oxidized low-density lipoprotein (OxLDL) reduced insulin content, decreased PDX-1 expression, and impaired glucose-stimulated insulin secretion (GSIS) in INS-1 cells, which were rescued by addition of high-density lipoprotein (HDL). OxLDL receptors and cholesterol content were increased by OxLDL. Consistently, OxLDL suppressed cholesterol transporter ABCA1 expression and transcription in a dose-dependent and time-dependent manner. Inhibition of MEK by its specific inhibitor, PD98059, altered the effect of OxLDL on ABCA1 transcription and activation of ERK. Next, chromatin immunoprecipitation assay demonstrated that liver X receptor (LXR) could directly bind to ABCA1 promoter and this binding was inhibited by OxLDL. Furthermore, OxLDL decreased the nuclear LXR expression, which was prevented by HDL. LXR-enhanced ABCA1 transcription was suppressed by OxLDL, and the effect was cancelled by mutation of the LXR-binding sites. In summary, our study shows that OxLDL down-regulates ABCA1 expression by MEK/ERK/LXR pathway, leading to cholesterol accumulation in INS-1 cells, which may result in impaired insulin synthesis and GSIS.
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Affiliation(s)
- Jingya Lyu
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou 510632, China;
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, 1750-1, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (K.F.); (H.I.); (S.S.); (T.K.); (T.S.); (T.I.); (T.Y.)
| | - Kensaku Fukunaga
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, 1750-1, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (K.F.); (H.I.); (S.S.); (T.K.); (T.S.); (T.I.); (T.Y.)
| | - Hitomi Imachi
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, 1750-1, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (K.F.); (H.I.); (S.S.); (T.K.); (T.S.); (T.I.); (T.Y.)
| | - Seisuke Sato
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, 1750-1, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (K.F.); (H.I.); (S.S.); (T.K.); (T.S.); (T.I.); (T.Y.)
| | - Toshihiro Kobayashi
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, 1750-1, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (K.F.); (H.I.); (S.S.); (T.K.); (T.S.); (T.I.); (T.Y.)
| | - Takanobu Saheki
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, 1750-1, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (K.F.); (H.I.); (S.S.); (T.K.); (T.S.); (T.I.); (T.Y.)
| | - Tomohiro Ibata
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, 1750-1, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (K.F.); (H.I.); (S.S.); (T.K.); (T.S.); (T.I.); (T.Y.)
| | - Takafumi Yoshimura
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, 1750-1, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (K.F.); (H.I.); (S.S.); (T.K.); (T.S.); (T.I.); (T.Y.)
| | - Hisakazu Iwama
- Life Science Research Center, Kagawa University, 1750-1, Miki-cho, Kita-gun, Kagawa 761-0793, Japan;
| | - Koji Murao
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, 1750-1, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (K.F.); (H.I.); (S.S.); (T.K.); (T.S.); (T.I.); (T.Y.)
- Correspondence:
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Li H, Yu XH, Ou X, Ouyang XP, Tang CK. Hepatic cholesterol transport and its role in non-alcoholic fatty liver disease and atherosclerosis. Prog Lipid Res 2021; 83:101109. [PMID: 34097928 DOI: 10.1016/j.plipres.2021.101109] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 12/12/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a quickly emerging global health problem representing the most common chronic liver disease in the world. Atherosclerotic cardiovascular disease represents the leading cause of mortality in NAFLD patients. Cholesterol metabolism has a crucial role in the pathogenesis of both NAFLD and atherosclerosis. The liver is the major organ for cholesterol metabolism. Abnormal hepatic cholesterol metabolism not only leads to NAFLD but also drives the development of atherosclerotic dyslipidemia. The cholesterol level in hepatocytes reflects the dynamic balance between endogenous synthesis, uptake, esterification, and export, a process in which cholesterol is converted to neutral cholesteryl esters either for storage in cytosolic lipid droplets or for secretion as a major constituent of plasma lipoproteins, including very-low-density lipoproteins, chylomicrons, high-density lipoproteins, and low-density lipoproteins. In this review, we describe decades of research aimed at identifying key molecules and cellular players involved in each main aspect of hepatic cholesterol metabolism. Furthermore, we summarize the recent advances regarding the biological processes of hepatic cholesterol transport and its role in NAFLD and atherosclerosis.
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Affiliation(s)
- Heng Li
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan International Scientific and Technological Cooperation Base of Arteriosclerotic Disease, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China
| | - Xiao-Hua Yu
- Institute of Clinical Medicine, The Second Affiliated Hospital of Hainan Medical University, Haikou, Hainan 460106, China
| | - Xiang Ou
- Department of Endocrinology, the First Hospital of Changsha, Changsha, Hunan 410005, China
| | - Xin-Ping Ouyang
- Department of Physiology, Institute of Neuroscience Research, Hengyang Key Laboratory of Neurodegeneration and Cognitive Impairment, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China.
| | - Chao-Ke Tang
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan International Scientific and Technological Cooperation Base of Arteriosclerotic Disease, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China.
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Colardo M, Martella N, Pensabene D, Siteni S, Di Bartolomeo S, Pallottini V, Segatto M. Neurotrophins as Key Regulators of Cell Metabolism: Implications for Cholesterol Homeostasis. Int J Mol Sci 2021; 22:5692. [PMID: 34073639 PMCID: PMC8198482 DOI: 10.3390/ijms22115692] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 12/14/2022] Open
Abstract
Neurotrophins constitute a family of growth factors initially characterized as predominant mediators of nervous system development, neuronal survival, regeneration and plasticity. Their biological activity is promoted by the binding of two different types of receptors, leading to the generation of multiple and variegated signaling cascades in the target cells. Increasing evidence indicates that neurotrophins are also emerging as crucial regulators of metabolic processes in both neuronal and non-neuronal cells. In this context, it has been reported that neurotrophins affect redox balance, autophagy, glucose homeostasis and energy expenditure. Additionally, the trophic support provided by these secreted factors may involve the regulation of cholesterol metabolism. In this review, we examine the neurotrophins' signaling pathways and their effects on metabolism by critically discussing the most up-to-date information. In particular, we gather experimental evidence demonstrating the impact of these growth factors on cholesterol metabolism.
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Affiliation(s)
- Mayra Colardo
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy; (M.C.); (N.M.); (D.P.); (S.D.B.)
| | - Noemi Martella
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy; (M.C.); (N.M.); (D.P.); (S.D.B.)
| | - Daniele Pensabene
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy; (M.C.); (N.M.); (D.P.); (S.D.B.)
| | - Silvia Siteni
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA;
| | - Sabrina Di Bartolomeo
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy; (M.C.); (N.M.); (D.P.); (S.D.B.)
| | - Valentina Pallottini
- Department of Science, University Roma Tre, Viale Marconi 446, 00146 Rome, Italy;
- Neuroendocrinology Metabolism and Neuropharmacology Unit, IRCSS Fondazione Santa Lucia, Via del Fosso Fiorano 64, 00143 Rome, Italy
| | - Marco Segatto
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy; (M.C.); (N.M.); (D.P.); (S.D.B.)
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Participation of ABCA1 Transporter in Pathogenesis of Chronic Obstructive Pulmonary Disease. Int J Mol Sci 2021; 22:ijms22073334. [PMID: 33805156 PMCID: PMC8037621 DOI: 10.3390/ijms22073334] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/19/2021] [Accepted: 03/22/2021] [Indexed: 12/12/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is the important medical and social problem. According to modern concepts, COPD is a chronic inflammatory disease, macrophages play a key role in its pathogenesis. Macrophages are heterogeneous in their functions, which is largely determined by their immunometabolic profile, as well as the features of lipid homeostasis, in which the ATP binding cassette transporter A1 (ABCA1) plays an essential role. The objective of this work is the analysis of the ABCA1 protein participation and the function of reverse cholesterol transport in the pathogenesis of COPD. The expression of the ABCA1 gene in lung tissues takes the second place after the liver, which indicates the important role of the carrier in lung function. The participation of the transporter in the development of COPD consists in provision of lipid metabolism, regulation of inflammation, phagocytosis, and apoptosis. Violation of the processes in which ABCA1 is involved may be a part of the pathophysiological mechanisms, leading to the formation of a heterogeneous clinical course of the disease.
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Chelakkot VS, Liu K, Yoshioka E, Saha S, Xu D, Licursi M, Dorward A, Hirasawa K. MEK reduces cancer-specific PpIX accumulation through the RSK-ABCB1 and HIF-1α-FECH axes. Sci Rep 2020; 10:22124. [PMID: 33335181 PMCID: PMC7747616 DOI: 10.1038/s41598-020-79144-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 12/01/2020] [Indexed: 02/07/2023] Open
Abstract
The efficacy of aminolevulinic acid (5-ALA)-based photodynamic diagnosis (5-ALA-PDD) and photodynamic therapy (5-ALA-PDT) is dependent on 5-ALA-induced cancer-specific accumulation of protoporphyrin IX (PpIX). We previously reported that inhibition of oncogenic Ras/MEK increases PpIX accumulation in cancer cells by reducing PpIX efflux through ATP-binding cassette sub-family B member 1 (ABCB1) and ferrochelatase (FECH)-catalysed PpIX conversion to haem. Here, we sought to identify the downstream pathways of Ras/MEK involved in the regulation of PpIX accumulation via ABCB1 and FECH. First, we demonstrated that Ras/MEK activation reduced PpIX accumulation in RasV12-transformed NIH3T3 cells and HRAS transgenic mice. Knockdown of p90 ribosomal S6 kinases (RSK) 2, 3, or 4 increased PpIX accumulation in RasV12-transformed NIH3T3 cells. Further, treatment with an RSK inhibitor reduced ABCB1 expression and increased PpIX accumulation. Moreover, HIF-1α expression was reduced when RasV12-transformed NIH3T3 cells were treated with a MEK inhibitor, demonstrating that HIF-1α is a downstream element of MEK. HIF-1α inhibition decreased FECH activity and increased PpIX accumulation. Finally, we demonstrated the involvement of RSKs and HIF-1α in the regulation of PpIX accumulation in human cancer cell lines. These results demonstrate that the RSK-ABCB1 and HIF-1α-FECH axes are the downstream pathways of Ras/MEK involved in the regulation of PpIX accumulation.
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Affiliation(s)
- Vipin Shankar Chelakkot
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, 300 Prince Philip Drive, St. John's, NL, A1B 3V6, Canada
| | - Kaiwen Liu
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, 300 Prince Philip Drive, St. John's, NL, A1B 3V6, Canada
| | - Ema Yoshioka
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, 300 Prince Philip Drive, St. John's, NL, A1B 3V6, Canada
| | - Shaykat Saha
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, 300 Prince Philip Drive, St. John's, NL, A1B 3V6, Canada
| | - Danyang Xu
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, 300 Prince Philip Drive, St. John's, NL, A1B 3V6, Canada
| | - Maria Licursi
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, 300 Prince Philip Drive, St. John's, NL, A1B 3V6, Canada
| | - Ann Dorward
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, 300 Prince Philip Drive, St. John's, NL, A1B 3V6, Canada
| | - Kensuke Hirasawa
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, 300 Prince Philip Drive, St. John's, NL, A1B 3V6, Canada.
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Frambach SJCM, de Haas R, Smeitink JAM, Rongen GA, Russel FGM, Schirris TJJ. Brothers in Arms: ABCA1- and ABCG1-Mediated Cholesterol Efflux as Promising Targets in Cardiovascular Disease Treatment. Pharmacol Rev 2020; 72:152-190. [PMID: 31831519 DOI: 10.1124/pr.119.017897] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Atherosclerosis is a leading cause of cardiovascular disease worldwide, and hypercholesterolemia is a major risk factor. Preventive treatments mainly focus on the effective reduction of low-density lipoprotein cholesterol, but their therapeutic value is limited by the inability to completely normalize atherosclerotic risk, probably due to the disease complexity and multifactorial pathogenesis. Consequently, high-density lipoprotein cholesterol gained much interest, as it appeared to be cardioprotective due to its major role in reverse cholesterol transport (RCT). RCT facilitates removal of cholesterol from peripheral tissues, including atherosclerotic plaques, and its subsequent hepatic clearance into bile. Therefore, RCT is expected to limit plaque formation and progression. Cellular cholesterol efflux is initiated and propagated by the ATP-binding cassette (ABC) transporters ABCA1 and ABCG1. Their expression and function are expected to be rate-limiting for cholesterol efflux, which makes them interesting targets to stimulate RCT and lower atherosclerotic risk. This systematic review discusses the molecular mechanisms relevant for RCT and ABCA1 and ABCG1 function, followed by a critical overview of potential pharmacological strategies with small molecules to enhance cellular cholesterol efflux and RCT. These strategies include regulation of ABCA1 and ABCG1 expression, degradation, and mRNA stability. Various small molecules have been demonstrated to increase RCT, but the underlying mechanisms are often not completely understood and are rather unspecific, potentially causing adverse effects. Better understanding of these mechanisms could enable the development of safer drugs to increase RCT and provide more insight into its relation with atherosclerotic risk. SIGNIFICANCE STATEMENT: Hypercholesterolemia is an important risk factor of atherosclerosis, which is a leading pathological mechanism underlying cardiovascular disease. Cholesterol is removed from atherosclerotic plaques and subsequently cleared by the liver into bile. This transport is mediated by high-density lipoprotein particles, to which cholesterol is transferred via ATP-binding cassette transporters ABCA1 and ABCG1. Small-molecule pharmacological strategies stimulating these transporters may provide promising options for cardiovascular disease treatment.
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Affiliation(s)
- Sanne J C M Frambach
- Department of Pharmacology and Toxicology, Radboud Institute for Molecular Life Sciences (S.J.C.M.F., G.A.R., F.G.M.R., T.J.J.S.), Radboud Center for Mitochondrial Medicine (S.J.C.M.F., R.d.H., J.A.M.S., F.G.M.R., T.J.J.S.), Department of Pediatrics (R.d.H., J.A.M.S.), and Department of Internal Medicine, Radboud Institute for Health Sciences (G.A.R.), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ria de Haas
- Department of Pharmacology and Toxicology, Radboud Institute for Molecular Life Sciences (S.J.C.M.F., G.A.R., F.G.M.R., T.J.J.S.), Radboud Center for Mitochondrial Medicine (S.J.C.M.F., R.d.H., J.A.M.S., F.G.M.R., T.J.J.S.), Department of Pediatrics (R.d.H., J.A.M.S.), and Department of Internal Medicine, Radboud Institute for Health Sciences (G.A.R.), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jan A M Smeitink
- Department of Pharmacology and Toxicology, Radboud Institute for Molecular Life Sciences (S.J.C.M.F., G.A.R., F.G.M.R., T.J.J.S.), Radboud Center for Mitochondrial Medicine (S.J.C.M.F., R.d.H., J.A.M.S., F.G.M.R., T.J.J.S.), Department of Pediatrics (R.d.H., J.A.M.S.), and Department of Internal Medicine, Radboud Institute for Health Sciences (G.A.R.), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Gerard A Rongen
- Department of Pharmacology and Toxicology, Radboud Institute for Molecular Life Sciences (S.J.C.M.F., G.A.R., F.G.M.R., T.J.J.S.), Radboud Center for Mitochondrial Medicine (S.J.C.M.F., R.d.H., J.A.M.S., F.G.M.R., T.J.J.S.), Department of Pediatrics (R.d.H., J.A.M.S.), and Department of Internal Medicine, Radboud Institute for Health Sciences (G.A.R.), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frans G M Russel
- Department of Pharmacology and Toxicology, Radboud Institute for Molecular Life Sciences (S.J.C.M.F., G.A.R., F.G.M.R., T.J.J.S.), Radboud Center for Mitochondrial Medicine (S.J.C.M.F., R.d.H., J.A.M.S., F.G.M.R., T.J.J.S.), Department of Pediatrics (R.d.H., J.A.M.S.), and Department of Internal Medicine, Radboud Institute for Health Sciences (G.A.R.), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tom J J Schirris
- Department of Pharmacology and Toxicology, Radboud Institute for Molecular Life Sciences (S.J.C.M.F., G.A.R., F.G.M.R., T.J.J.S.), Radboud Center for Mitochondrial Medicine (S.J.C.M.F., R.d.H., J.A.M.S., F.G.M.R., T.J.J.S.), Department of Pediatrics (R.d.H., J.A.M.S.), and Department of Internal Medicine, Radboud Institute for Health Sciences (G.A.R.), Radboud University Medical Center, Nijmegen, The Netherlands
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12
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Abdelhamid M, Jung CG, Zhou C, Abdullah M, Nakano M, Wakabayashi H, Abe F, Michikawa M. Dietary Lactoferrin Supplementation Prevents Memory Impairment and Reduces Amyloid-β Generation in J20 Mice. J Alzheimers Dis 2020; 74:245-259. [DOI: 10.3233/jad-191181] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Mona Abdelhamid
- Department of Biochemistry, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Aichi, Japan
| | - Cha-Gyun Jung
- Department of Biochemistry, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Aichi, Japan
| | - Chunyu Zhou
- Department of Biochemistry, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Aichi, Japan
| | - Mohammad Abdullah
- Department of Biochemistry, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Aichi, Japan
| | - Manabu Nakano
- Food Ingredients and Technology Institute, Morinaga Milk Industry Co, Ltd. Zama, Kanagawa, Japan
| | - Hiroyuki Wakabayashi
- Food Ingredients and Technology Institute, Morinaga Milk Industry Co, Ltd. Zama, Kanagawa, Japan
| | - Fumiaki Abe
- Food Ingredients and Technology Institute, Morinaga Milk Industry Co, Ltd. Zama, Kanagawa, Japan
| | - Makoto Michikawa
- Department of Biochemistry, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Aichi, Japan
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13
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Malhotra P, Soni V, Yamanashi Y, Takada T, Suzuki H, Gill RK, Saksena S, Dudeja PK, Alrefai WA. Mechanisms of Niemann-Pick type C1 Like 1 protein degradation in intestinal epithelial cells. Am J Physiol Cell Physiol 2019; 316:C559-C566. [PMID: 30789754 PMCID: PMC6482670 DOI: 10.1152/ajpcell.00465.2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 12/24/2018] [Accepted: 02/12/2019] [Indexed: 01/06/2023]
Abstract
Intestinal Niemann-Pick C1 Like 1 (NPC1L1) protein plays a key role in cholesterol absorption. A decrease in NPC1L1 expression has been implicated in lowering plasma cholesterol and mitigating the risk for coronary heart disease. Little is known about the mechanisms responsible for NPC1L1 protein degradation that upon activation may lead to a reduction in NPC1L1 protein levels in intestinal epithelial cells (IECs). In current studies, the human intestinal Caco-2 and HuTu-80 cell lines expressing NPC1L1-hemagglutinin fusion protein were used to investigate the mechanisms of NPC1L1 protein degradation. Incubation with the proteasome inhibitors MG-132 and lactacystin (10 μM, 24 h) significantly increased NPC1L1 protein levels in IECs. Also, the inhibition of the lysosomal pathway with bafilomycin A1 (80 nM, 24 h) resulted in a significant increase in NPC1L1 protein levels. Immunoprecipitation studies showed that NPC1L1 protein is both a poly- and monoubiquinated polypeptide and that the inhibition of the proteasomal pathway remarkably increased the level of the polyubiquinated NPC1L1. The surface expression of NPC1L1 was increased by the inhibition of both proteasomal and lysosomal pathways. Furthermore, the pharmacological inhibition of mitogen-activated protein kinase pathway (PD-98059, 15 μM, 24 h) and siRNA silencing of ERK1/2 resulted in a significant decrease in NPC1L1 protein levels in IECs. In conclusion, our results showed that basal level of intestinal cholesterol transporter NPC1L1 protein is modulated by both ubiquitin proteasome- and lysosome-dependent degradation as well as by ERK1/2-dependent pathway. The modulation of these pathways may provide novel clues for therapeutic intervention to inhibit cholesterol absorption and lower plasma cholesterol.
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Affiliation(s)
- Pooja Malhotra
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago , Chicago, Illinois
| | - Vinay Soni
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago , Chicago, Illinois
| | - Yoshihide Yamanashi
- Department of Pharmacy, The University of Tokyo Hospital , Tokyo , Japan
- Faculty of Medicine, The University of Tokyo , Tokyo , Japan
| | - Tappei Takada
- Department of Pharmacy, The University of Tokyo Hospital , Tokyo , Japan
- Faculty of Medicine, The University of Tokyo , Tokyo , Japan
| | - Hiroshi Suzuki
- Department of Pharmacy, The University of Tokyo Hospital , Tokyo , Japan
- Faculty of Medicine, The University of Tokyo , Tokyo , Japan
| | - Ravinder K Gill
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago , Chicago, Illinois
| | - Seema Saksena
- Jesse Brown Veterans Affairs Medical Center , Chicago, Illinois
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago , Chicago, Illinois
| | - Pradeep K Dudeja
- Jesse Brown Veterans Affairs Medical Center , Chicago, Illinois
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago , Chicago, Illinois
| | - Waddah A Alrefai
- Jesse Brown Veterans Affairs Medical Center , Chicago, Illinois
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago , Chicago, Illinois
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14
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Chen S, Wang F, Liu Z, Zhao Y, Jiang Y, Chen L, Li C, Zhou X. Brain-derived neurotrophic factor promotes proliferation and progesterone synthesis in bovine granulosa cells. J Cell Physiol 2018; 234:8776-8787. [PMID: 30456817 DOI: 10.1002/jcp.27536] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Accepted: 09/10/2018] [Indexed: 12/15/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is involved in regulating the growth of ovarian follicles, maturation of the oocyte, and development of the early embryo through its receptor, tyrosine kinase receptor B (TrkB). However, it is still unclear as to how BDNF influences proliferation and steroidogenesis of bovine granulosa cells (GCs). In this paper, we confirmed that BDNF and TrkB were expressed in bovine GCs, and that proliferation and steroidogenesis by bovine GCs were reduced by knockdown of BDNF or inhibition of TrkB. With respect to GC proliferation, BDNF enhanced cellular viability and the percentage of cells in the S phase. BDNF also activated both protein kinase B (PKB, also known as AKT) and the extracellular signal-regulated protein kinase 1/2 (ERK1/2)-signaling pathway. Through the AKT-signaling pathway, BDNF increased the expression of proliferation-related genes, including cyclin A1 (CCNA1), cyclin E2 (CCNE2), cyclin D1 (CCND1), and cyclin-dependent kinase 1 (CDK1). However, through the ERK1/2 signaling pathway, BDNF only increased the expression of CCNA1 and CCNE2. Regarding steroidogenesis by bovine GCs, BDNF promoted progesterone (P 4 ) synthesis, but had no effect on estradiol; it also activated the AKT-signaling pathway and increased the expression of steroidogenesis-related genes, including steroidogenic acute regulatory protein (STAR) and hydroxy-δ-5-steroid dehydrogenase, 3β- and steroid δ-isomerase 1 (HSD3B1). In summary, our data are the first to show that BDNF promotes the proliferation of bovine GCs through TrkB-AKT and ERK1/2 signaling pathways and increases P4 synthesis by bovine GCs through the TrkB-AKT signaling pathway.
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Affiliation(s)
- Shuxiong Chen
- Laboratory for Regulation of Reproduction, College of Animal Sciences, Jilin University, Changchun, China
| | - Fengge Wang
- Laboratory for Regulation of Reproduction, College of Animal Sciences, Jilin University, Changchun, China
| | - Zhuo Liu
- Laboratory for Regulation of Reproduction, College of Animal Sciences, Jilin University, Changchun, China
| | - Yun Zhao
- Laboratory for Regulation of Reproduction, College of Animal Sciences, Jilin University, Changchun, China
| | - Yanwen Jiang
- Laboratory for Regulation of Reproduction, College of Animal Sciences, Jilin University, Changchun, China
| | - Lu Chen
- Laboratory for Regulation of Reproduction, College of Animal Sciences, Jilin University, Changchun, China
| | - Chunjin Li
- Laboratory for Regulation of Reproduction, College of Animal Sciences, Jilin University, Changchun, China
| | - Xu Zhou
- Laboratory for Regulation of Reproduction, College of Animal Sciences, Jilin University, Changchun, China
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15
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Riganti C, Castella B, Massaia M. ABCA1, apoA-I, and BTN3A1: A Legitimate Ménage à Trois in Dendritic Cells. Front Immunol 2018; 9:1246. [PMID: 29937767 PMCID: PMC6002486 DOI: 10.3389/fimmu.2018.01246] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 05/17/2018] [Indexed: 12/11/2022] Open
Abstract
Human Vγ9Vδ2 T cells have the capacity to detect supra-physiological concentrations of phosphoantigens (pAgs) generated by the mevalonate (Mev) pathway of mammalian cells under specific circumstances. Isopentenyl pyrophosphate (IPP) is the prototypic pAg recognized by Vγ9Vδ2 T cells. B-cell derived tumor cells (i.e., lymphoma and myeloma cells) and dendritic cells (DCs) are privileged targets of Vγ9Vδ2 T cells because they generate significant amounts of IPP which can be boosted with zoledronic acid (ZA). ZA is the most potent aminobisphosphonate (NBP) clinically available to inhibit osteoclast activation and a very potent inhibitor of farnesyl pyrophosphate synthase in the Mev pathway. ZA-treated DCs generate and release in the supernatants picomolar IPP concentrations which are sufficient to induce the activation of Vγ9Vδ2 T cells. We have recently shown that the ATP-binding cassette transporter A1 (ABCA1) plays a major role in the extracellular release of IPP from ZA-treated DCs. This novel ABCA1 function is fine-tuned by physical interactions with IPP, apolipoprotein A-I (apoA-I), and butyrophilin-3A1 (BTN3A1). The mechanisms by which soluble IPP induces Vγ9Vδ2 T-cell activation remain to be elucidated. It is possible that soluble IPP binds to BTN3A1, apoA-I, or other unknown molecules on the cell surface of bystander cells like monocytes, NK cells, Vγ9Vδ2 T cells, or any other cell locally present. Investigating this scenario may represent a unique opportunity to further characterize the role of BTN3A1 and other molecules in the recognition of soluble IPP by Vγ9Vδ2 T cells.
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Affiliation(s)
- Chiara Riganti
- Dipartimento di Oncologia, Università degli Studi di Torino, Turin, Italy
| | - Barbara Castella
- Laboratorio di Immunologia dei Tumori del Sangue (LITS), Centro Interdipartimentale di Ricerca in Biologia Molecolare (CIRBM), Università degli Studi di Torino, Turin, Italy
| | - Massimo Massaia
- Laboratorio di Immunologia dei Tumori del Sangue (LITS), Centro Interdipartimentale di Ricerca in Biologia Molecolare (CIRBM), Università degli Studi di Torino, Turin, Italy.,SC Ematologia, AO S. Croce e Carle, Cuneo, Italy
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16
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Spagnuolo MS, Donizetti A, Iannotta L, Aliperti V, Cupidi C, Bruni AC, Cigliano L. Brain-derived neurotrophic factor modulates cholesterol homeostasis and Apolipoprotein E synthesis in human cell models of astrocytes and neurons. J Cell Physiol 2018; 233:6925-6943. [PMID: 29323721 DOI: 10.1002/jcp.26480] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 01/05/2018] [Indexed: 12/12/2022]
Abstract
In the central nervous system, cholesterol is critical to maintain membrane plasticity, cellular function, and synaptic integrity. In recent years, much attention was focused on the role of cholesterol in brain since a breakdown of cholesterol metabolism has been associated with different diseases. Brain-derived neurotrophic factor (BDNF) was previously reported to elicit cholesterol biosynthesis and promote the accumulation of presynaptic proteins in cholesterol-rich lipid rafts, but no data are available on its ability to modulate physiological mechanisms involved in cholesterol homeostasis. Major aim of this research was to investigate whether BDNF influences cholesterol homeostasis, focusing on the effect of the neurotrophin on Apolipoprotein E (ApoE) synthesis, cholesterol efflux from astrocytes and cholesterol incorporation into neurons. Our results show that BDNF significantly stimulates cholesterol efflux by astrocytes, as well as ATP binding cassette A1 (ABCA1) transporter and ApoE expression. Conversely, cholesterol uptake in neurons was downregulated by BDNF. This effect was associated with the increase of Liver X Receptor (LXR)-beta expression in neuron exposed to BDNF. The level of apoptosis markers, that is, cleaved caspase 3 and poly ADP ribose polymerase (PARP), was found increased in neurons treated with high cholesterol, but significantly lower when the cells were exposed to cholesterol in the presence of BDNF, thus suggesting a neuroprotective role of the neurotrophin, likely through its reducing effect of neuronal cholesterol uptake. Interestingly, cholesterol stimulates BDNF production by neurons. Overall, our findings evidenced a novel role of BDNF in the modulation of ApoE and cholesterol homeostasis in glial and neuronal cells.
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Affiliation(s)
- Maria S Spagnuolo
- Department of Bio-Agrofood Science, Institute for the Animal Production System in Mediterranean Environment, National Research Council, Naples, Italy
| | - Aldo Donizetti
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Lucia Iannotta
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Vincenza Aliperti
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Chiara Cupidi
- Centro Regionale di Neurogenetica, via Perugini, ASP Catanzaro, Lamezia Terme (CZ), Italy
| | - Amalia C Bruni
- Centro Regionale di Neurogenetica, via Perugini, ASP Catanzaro, Lamezia Terme (CZ), Italy
| | - Luisa Cigliano
- Department of Biology, University of Naples Federico II, Naples, Italy
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Jalmi SK, Bhagat PK, Verma D, Noryang S, Tayyeba S, Singh K, Sharma D, Sinha AK. Traversing the Links between Heavy Metal Stress and Plant Signaling. FRONTIERS IN PLANT SCIENCE 2018; 9:12. [PMID: 29459874 PMCID: PMC5807407 DOI: 10.3389/fpls.2018.00012] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Accepted: 01/03/2018] [Indexed: 05/17/2023]
Abstract
Plants confront multifarious environmental stresses widely divided into abiotic and biotic stresses, of which heavy metal stress represents one of the most damaging abiotic stresses. Heavy metals cause toxicity by targeting crucial molecules and vital processes in the plant cell. One of the approaches by which heavy metals act in plants is by over production of reactive oxygen species (ROS) either directly or indirectly. Plants act against such overdose of metal in the environment by boosting the defense responses like metal chelation, sequestration into vacuole, regulation of metal intake by transporters, and intensification of antioxidative mechanisms. This response shown by plants is the result of intricate signaling networks functioning in the cell in order to transmit the extracellular stimuli into an intracellular response. The crucial signaling components involved are calcium signaling, hormone signaling, and mitogen activated protein kinase (MAPK) signaling that are discussed in this review. Apart from signaling components other regulators like microRNAs and transcription factors also have a major contribution in regulating heavy metal stress. This review demonstrates the key role of MAPKs in synchronously controlling the other signaling components and regulators in metal stress. Further, attempts have been made to focus on metal transporters and chelators that are regulated by MAPK signaling.
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Affiliation(s)
| | | | | | | | | | | | | | - Alok K. Sinha
- Plant Signaling, National Institute of Plant Genome Research, New Delhi, India
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18
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Ni J, Li Y, Li W, Guo R. Salidroside protects against foam cell formation and apoptosis, possibly via the MAPK and AKT signaling pathways. Lipids Health Dis 2017; 16:198. [PMID: 29017559 PMCID: PMC5635575 DOI: 10.1186/s12944-017-0582-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 09/26/2017] [Indexed: 12/13/2022] Open
Abstract
Background Foam cell formation and apoptosis are closely associated with atherosclerosis pathogenesis. We determined the effect of salidroside on oxidized low-density lipoprotein (ox-LDL)-induced foam cell formation and apoptosis in THP1 human acute monocytic leukemia cells and investigated the associated molecular mechanisms. Methods THP1-derived macrophages were incubated with salidroside for 5 h and then exposed to ox-LDL for 24 h to induce foam cell formation. Cytotoxicity, lipid deposition, apoptosis, and the expression of various proteins were tested using the CCK8 kit, Oil Red O staining, flow cytometry, and western blotting, respectively. Results Ox-LDL treatment alone promoted macrophage-derived foam cell formation, while salidroside treatment alone inhibited it (p < 0.05). The number of early/late apoptotic cells decreased with salidroside treatment in a dose-dependent manner (p < 0.05). Salidroside dramatically upregulated nuclear factor erythroid 2-related factor 2, but had no effect on heme oxygenase-1 expression; moreover, it markedly downregulated ox-LDL receptor 1 and upregulated ATP-binding cassette transporter A1. Salidroside also obviously decreased the phosphorylation of JNK, ERK, p38 MAPK, and increased that of Akt. However, the total expression of these proteins was not affected. Conclusion Based on our findings, we speculate that salidroside can suppress ox-LDL-induced THP1-derived foam cell formation and apoptosis, partly by regulating the MAPK and Akt signaling pathways.
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Affiliation(s)
- Jing Ni
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, 301 Yan Chang Zhong Road, Shanghai, 200072, China
| | - Yuanmin Li
- Department of Cardio-Thoracic Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, 301 Yan Chang Zhong Road, Shanghai, 200072, China
| | - Weiming Li
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, 301 Yan Chang Zhong Road, Shanghai, 200072, China.
| | - Rong Guo
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, 301 Yan Chang Zhong Road, Shanghai, 200072, China.
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Intracranial IL-17A overexpression decreases cerebral amyloid angiopathy by upregulation of ABCA1 in an animal model of Alzheimer's disease. Brain Behav Immun 2017; 65:262-273. [PMID: 28526436 PMCID: PMC5537015 DOI: 10.1016/j.bbi.2017.05.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 05/15/2017] [Accepted: 05/16/2017] [Indexed: 01/18/2023] Open
Abstract
Neuroinflammation is a pervasive feature of Alzheimer's disease (AD) and characterized by activated microglia, increased proinflammatory cytokines and/or infiltrating immune cells. T helper 17 (Th17) cells are found in AD brain parenchyma and interleukin-17A (IL-17A) is identified around deposits of aggregated amyloid β protein (Aβ). However, the role of IL-17A in AD pathogenesis remains elusive. We overexpressed IL-17A in an AD mouse model via recombinant adeno-associated virus serotype 5 (rAAV5)-mediated intracranial gene delivery. AD model mice subjected to injection of a vehicle (PBS) or rAAV5 carrying the lacZ gene served as controls. IL-17A did not exacerbate neuroinflammation in IL-17A-overexpressing mice. We found that IL-17A overexpression markedly improved glucose metabolism, decreased soluble Aβ levels in the hippocampus and cerebrospinal fluid, drastically reduced cerebral amyloid angiopathy, and modestly but significantly improved anxiety and learning deficits. Moreover, the ATP-binding cassette subfamily A member 1 (ABCA1), which can transport Aβ from the brain into the blood circulation, significantly increased in IL-17A-overexpressing mice. In vitro treatment of brain endothelial bEnd.3 cells with IL-17A induced a dose-dependent increase in protein expression of ABCA1 through ERK activation. Our study suggests that IL-17A may decrease Aβ levels in the brain by upregulating ABCA1 in blood-brain barrier endothelial cells.
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20
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Gao XQ, Li YF, Jiang ZL. β 3-Adrenoceptor activation upregulates apolipoprotein A-I expression in HepG2 cells, which might further promote cholesterol efflux from macrophage foam cells. Drug Des Devel Ther 2017; 11:617-627. [PMID: 28424539 PMCID: PMC5344441 DOI: 10.2147/dddt.s130088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Objective The aim of this study was to explore the effects of β3-adrenoceptor (β3-AR) activation on HepG2 cells and its influence on cholesterol efflux from macrophage foam cells. Materials and methods HepG2 cells were cultured and treated with the β3-AR agonist, BRL37344, and antagonist, SR52390A, and the expression of apolipoprotein (Apo) A-I, ApoA-II, ApoB, and β3-AR in the supernatants and cells was determined. The expression of peroxisome proliferator-activated receptor (PPAR) γ and PPARα in the HepG2 cells was also assessed. Next, using the RAW264.7 macrophage foam cell model, we also assessed the influence of the HepG2 cell supernatants on lipid efflux. The cholesterol content of the foam cells was also measured, and the cholesterol efflux from the macrophages was examined by determining 3H-labeled cholesterol levels. Expression of ATP-binding cassette transporter (ABC) A1 and ABCG1 of the macrophage foam cells was also assessed. Results β3-AR activation increased ApoA-I expression in both the HepG2 cells and the supernatants; PPARγ expression was upregulated, but PPARα expression was not. Treatment with GW9662 abolished the increased expression of ApoA-I induced by the β3-AR agonist. The HepG2 cell supernatants decreased the lipid accumulation and increased the cholesterol efflux from the macrophage foam cells. ABCA1 expression, but not ABCG1 expression, increased in the macrophage foam cells treated with BRL37344-treated HepG2 cell supernatants. Conclusion Activation of β3-AR in HepG2 cells upregulates ApoA-I expression, which might further promote cholesterol efflux from macrophage foam cells. PPARγ might be required for the induction of ApoA-I expression.
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Affiliation(s)
- Xia-Qing Gao
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University.,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, People's Republic of China
| | - Yan-Fang Li
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University.,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, People's Republic of China
| | - Zhi-Li Jiang
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University.,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, People's Republic of China
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21
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Mehta D, Mehta KD. PKCβ: Expanding role in hepatic adaptation of cholesterol homeostasis to dietary fat/cholesterol. Am J Physiol Gastrointest Liver Physiol 2017; 312:G266-G273. [PMID: 28104587 PMCID: PMC5401991 DOI: 10.1152/ajpgi.00373.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 01/11/2017] [Accepted: 01/17/2017] [Indexed: 01/31/2023]
Abstract
Cholesterol homeostasis relies on an intricate network of cellular processes whose deregulation in response to Western type high-fat/cholesterol diets can lead to several life-threatening pathologies. Significant advances have been made in resolving the molecular identity and regulatory function of transcription factors sensitive to fat, cholesterol, or bile acids, but whether body senses the presence of both fat and cholesterol simultaneously is not known. Assessing the impact of a high-fat/cholesterol load, rather than an individual component alone, on cholesterol homeostasis is more physiologically relevant because Western diets deliver both fat and cholesterol at the same time. Moreover, dietary fat and dietary cholesterol are reported to act synergistically to impair liver cholesterol homeostasis. A key insight into the role of protein kinase C-β (PKCβ) in hepatic adaptation to high-fat/cholesterol diets was gained recently through the use of knockout mice. The emerging evidence indicates that PKCβ is an important regulator of cholesterol homeostasis that ensures normal adaptation to high-fat/cholesterol intake. Consistent with this function, high-fat/cholesterol diets induce PKCβ expression and signaling in the intestine and liver, while systemic PKCβ deficiency promotes accumulation of cholesterol in the liver and bile. PKCβ disruption results in profound dysregulation of hepatic cholesterol and bile homeostasis and imparts sensitivity to cholesterol gallstone formation. The available results support involvement of a two-pronged mechanism by which intestine and liver PKCβ signaling converge on liver ERK1/2 to dictate diet-induced cholesterol and bile acid homeostasis. Collectively, PKCβ is an integrator of dietary fat/cholesterol signal and mediates changes to cholesterol homeostasis.
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Affiliation(s)
- Devina Mehta
- 1Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio; and
| | - Kamal D. Mehta
- 2Department of Biological Chemistry and Pharmacology, Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
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Kemmerer M, Wittig I, Richter F, Brüne B, Namgaladze D. AMPK activates LXRα and ABCA1 expression in human macrophages. Int J Biochem Cell Biol 2016; 78:1-9. [DOI: 10.1016/j.biocel.2016.06.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 06/10/2016] [Accepted: 06/21/2016] [Indexed: 11/16/2022]
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23
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Zhang L, Chen Y, Yang X, Yang J, Cao X, Li X, Li L, Miao QR, Hajjar DP, Duan Y, Han J. MEK1/2 inhibitors activate macrophage ABCG1 expression and reverse cholesterol transport-An anti-atherogenic function of ERK1/2 inhibition. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1180-1191. [PMID: 27365310 DOI: 10.1016/j.bbalip.2016.06.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 06/03/2016] [Accepted: 06/24/2016] [Indexed: 02/07/2023]
Abstract
Expression of ATP-binding cassette transporter G1 (ABCG1), a molecule facilitating cholesterol efflux to HDL, is activated by liver X receptor (LXR). In this study, we investigated if inhibition of ERK1/2 can activate macrophage ABCG1 expression and functions. MEK1/2 inhibitors, PD98059 and U0126, increased ABCG1 mRNA and protein expression, and activated the natural ABCG1 promoter but not the promoter with the LXR responsive element (LXRE) deletion. Inhibition of ABCG1 expression by ABCG1 siRNA did enhance the formation of macrophage/foam cells and it attenuated the inhibitory effect of MEK1/2 inhibitors on foam cell formation. MEK1/2 inhibitors activated macrophage cholesterol efflux to HDL in vitro, and they enhanced reverse cholesterol transport (RCT) in vivo. ApoE deficient (apoE(-/-)) mice receiving U0126 treatment had reduced sinus lesions in the aortic root which was associated with activated macrophage ABCG1 expression in the lesion areas. MEK1/2 inhibitors coordinated the RXR agonist, but not the LXR agonist, to induce ABCG1 expression. Furthermore, induction of ABCG1 expression by MEK1/2 inhibitors was associated with activation of SIRT1, a positive regulator of LXR activity, and inactivation of SULT2B1 and RIP140, two negative regulators of LXR activity. Taken together, our study suggests that MEK1/2 inhibitors activate macrophage ABCG1 expression/RCT, and inhibit foam cell formation and lesion development by multiple mechanisms, supporting the concept that ERK1/2 inhibition is anti-atherogenic.
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Affiliation(s)
- Ling Zhang
- Department of Cardiology, Xijing Hospital, the 4th Military Medical University, Xi'an, China
| | - Yuanli Chen
- College of Biomedical Engineering, Hefei University of Technology, Hefei, China; School of Medicine, Nankai University, Tianjin, China
| | - Xiaoxiao Yang
- College of Life Sciences, Nankai University, Tianjin, China
| | - Jie Yang
- College of Life Sciences, Nankai University, Tianjin, China
| | - Xingyue Cao
- College of Life Sciences, Nankai University, Tianjin, China
| | - Xiaoju Li
- College of Life Sciences, Nankai University, Tianjin, China
| | - Luyuan Li
- College of Pharmacy, Nankai University, Tianjin, China
| | | | | | - Yajun Duan
- College of Biomedical Engineering, Hefei University of Technology, Hefei, China; College of Life Sciences, Nankai University, Tianjin, China; State Key Laboratory of Medicinal Chemical Biology, Collaborative Innovation Center of Biotherapy, Nankai University, Tianjin, China.
| | - Jihong Han
- College of Biomedical Engineering, Hefei University of Technology, Hefei, China; College of Life Sciences, Nankai University, Tianjin, China; State Key Laboratory of Medicinal Chemical Biology, Collaborative Innovation Center of Biotherapy, Nankai University, Tianjin, China.
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Li S, Wang C, Li K, Li L, Tian M, Xie J, Yang M, Jia Y, He J, Gao L, Boden G, Liu H, Yang G. NAMPT knockdown attenuates atherosclerosis and promotes reverse cholesterol transport in ApoE KO mice with high-fat-induced insulin resistance. Sci Rep 2016; 6:26746. [PMID: 27229177 PMCID: PMC4882618 DOI: 10.1038/srep26746] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 04/21/2016] [Indexed: 01/18/2023] Open
Abstract
NAMPT has been suggested association with atherosclerosis and insulin resistance. However, the impact of NAMPT on atherosclerosis remained unknown. Therefore, the objective of this study was to use a NAMPT loss-of-function approach to investigate the effect of NAMPT on atherosclerosis in hypercholesterolemic mice. We demonstrated that a specific NAMPT knockdown increased plasma HDL-C levels, reduced the plaque area of the total aorta en face and the cross-sectional aortic sinus, decreased macrophage number and apoptosis, and promoted RCT in HFD-fed ApoE KO mice. These changes were accompanied by increased PPARα, LXRα, ABCA1 and ABCG1 expressions in the liver. NAMPT knockdown also facilitated cholesterol efflux in RAW264.7 cells. We further investigated the effect of NAMPT knockdown on the PPARα-LXRα pathway of cholesterol metabolism with MK886 (a selective inhibitor of PPARα) in RAW264.7 macrophages. MK886 abolished the ability of NAMPT knockdown to decrease intracellular cholesterol levels to enhance the rate of (3)H-cholesterol efflux and to increase ABCA1/G1 and LXRα expressions in RAW264.7 macrophages. Our observations demonstrate that NAMPT knockdown exerted antiatherogenic effects by promoting cholesterol efflux and macrophage RCT through the PPARα- LXRα- ABCA1/G1pathway in vitro and in vivo.
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Affiliation(s)
- Shengbing Li
- Department of Endocrinology, the Second Affiliated Hospital, Chongqing Medical University, 400010 Chongqing, China
| | - Cong Wang
- Department of Endocrinology, the Second Affiliated Hospital, Chongqing Medical University, 400010 Chongqing, China
| | - Ke Li
- Department of Endocrinology, the Second Affiliated Hospital, Chongqing Medical University, 400010 Chongqing, China
| | - Ling Li
- The Key Laboratory of Laboratory Medical Diagnostics in the Ministry of Education and Department of Clinical Biochemistry, College of Laboratory Medicine, Chongqing Medical University, 400010 Chongqing, China
| | - Mingyuan Tian
- Department of Endocrinology, the Second Affiliated Hospital, Chongqing Medical University, 400010 Chongqing, China
| | - Jing Xie
- Department of Endocrinology, the Second Affiliated Hospital, Chongqing Medical University, 400010 Chongqing, China
| | - Mengliu Yang
- Department of Endocrinology, the Second Affiliated Hospital, Chongqing Medical University, 400010 Chongqing, China
| | - Yanjun Jia
- Department of Endocrinology, the Second Affiliated Hospital, Chongqing Medical University, 400010 Chongqing, China
| | - Junying He
- Department of Endocrinology, the Second Affiliated Hospital, Chongqing Medical University, 400010 Chongqing, China
| | - Lin Gao
- Department of Endocrinology, the Affiliated Hospital, Zunyi Medical College, 563003 Guizhou, China
| | - Guenther Boden
- The Division of Endocrinology/Diabetes/Metabolism and the Clinical Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Hua Liu
- Department of Pediatrics, University of Mississippi Medical Center, 2500 North State Street, Jackson, Mississippi, MS 39216-4505, USA
| | - Gangyi Yang
- Department of Endocrinology, the Second Affiliated Hospital, Chongqing Medical University, 400010 Chongqing, China
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Xue XH, Shi FF, Chen T, Wei W, Zhou XM, Chen LD. Inhibition of ERK1/2 improves lipid balance in rat macrophages via ABCA1/G1 and CD36. Mol Med Rep 2015; 13:1533-40. [PMID: 26707062 DOI: 10.3892/mmr.2015.4697] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 12/07/2015] [Indexed: 11/06/2022] Open
Abstract
ATP-binding cassette transporters A1 (ABCA1) and G1 (ABCG1), and macrophage scavenger receptor, cluster of differentiation (CD)36, function as key mediators of cholesterol efflux and influx from macrophages. In addition, they are associated with foam cell formation and the development of atherosclerosis (AS). The aim of the present study was to investigate the effects of extracellular signal-regulated kinases 1/2 (ERK1/2) inhibition on lipid balance in oxidized-low-density lipoprotein (Ox-LDL)-stimulated rat macrophages, and to examine the role of ERK1/2 inhibitors in AS. Rat peritoneal macrophages were treated with Ox-LDL alone or in combination with an ERK1/2 inhibitor, U0126, and untreated cells served as controls. Ox-LDL-induced lipid accumulation was detected by DiI fluorescence and oil red O staining. In addition, the mRNA and protein expression levels of ABCA1, ABCG1 and CD36 were determined using polymerase chain reaction and western blotting, respectively. Treatment with Ox-LDL significantly increased lipid accumulation and upregulated the mRNA and protein expression levels of ABCA1, ABCG1 and CD36 in macrophages. The addition of U0126 resulted in a marked reduction of lipid deposition, upregulation of ABCA1/G1 expression and suppression of CD36 expression in Ox-LDL-stimulated macrophages. The results of the present study indicated a novel association between ERK1/2 signaling and lipid metabolism, thus suggesting that inhibition of ERK1/2 may be considered a promising therapeutic strategy against AS.
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Affiliation(s)
- Xie-Hua Xue
- Department of Neurology, Rehabilitation Hospital Affiliated to Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350003, P.R. China
| | - Feng-Fei Shi
- Institute of Rehabilitation Medicine, Rehabilitation Technology Collaborative Innovation Center, College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350003, P.R. China
| | - Tong Chen
- Institute of Rehabilitation Medicine, Rehabilitation Technology Collaborative Innovation Center, College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350003, P.R. China
| | - Wei Wei
- Department of Neurology, Rehabilitation Hospital Affiliated to Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350003, P.R. China
| | - Xiao-Mao Zhou
- Institute of Rehabilitation Medicine, Rehabilitation Technology Collaborative Innovation Center, College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350003, P.R. China
| | - Li-Dian Chen
- Institute of Rehabilitation Medicine, Rehabilitation Technology Collaborative Innovation Center, College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350003, P.R. China
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Identification of dual PPARα/γ agonists and their effects on lipid metabolism. Bioorg Med Chem 2015; 23:7676-84. [DOI: 10.1016/j.bmc.2015.11.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 11/09/2015] [Accepted: 11/13/2015] [Indexed: 11/20/2022]
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Mostafa AM, Hamdy NM, El-Mesallamy HO, Abdel-Rahman SZ. Glucagon-like peptide 1 (GLP-1)-based therapy upregulates LXR-ABCA1/ABCG1 cascade in adipocytes. Biochem Biophys Res Commun 2015; 468:900-5. [PMID: 26603933 DOI: 10.1016/j.bbrc.2015.11.054] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 11/11/2015] [Indexed: 01/31/2023]
Abstract
A promising treatment for obesity involves the use of therapeutic agents that increase the level of the glucagon-like peptide (GLP-1) which reduces appetite and food intake. Native GLP-1 is rapidly metabolized by the dipeptidyl peptidase-4 (DPP-4) enzyme and, as such, GLP-1 mimetics or DPP-4 inhibitors represent promising treatment approaches. Interestingly, obese patient receiving such medications showed improved lipid profiles and cholesterol homeostasis, however the mechanism(s) involved are not known. Members of the ATP-binding cassette (ABC) transporters, including ABCA1 and ABCG1, play essential roles in reverse cholesterol transport and in high density lipoprotein (HDL) formation. These transporters are under the transcriptional regulation of liver X receptor alpha (LXR-α). We hypothesize that GLP-1 mimetics and/or DPP-4 inhibitors modulate ABCA1/ABCG1 expression in adipocytes through an LXR-α mediated process and thus affecting cholesterol homeostasis. 3T3-L1 adipocytes were treated with the DPP-4 inhibitor vildagliptin (2 nM) or the GLP-1 mimetic exendin-4 (5 nM). Gene and protein expression of ABCA1, ABCG1 and LXR-α were determined and correlated with cholesterol efflux. Expression levels of interleukin-6 (IL-6), leptin and the glucose transporter-4 (GLUT-4) were also determined. Treatment with both medications significantly increased the expression of ABCA1, ABCG1, LXR-α and GLUT-4, decreased IL-6 and leptin, and improved cholesterol efflux from adipocytes (P < 0.05). Our data suggest that GLP-1-based therapy modulate ABCA1/ABCG1 expression in adipocytes potentially through an LXR-α mediated process.
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Affiliation(s)
- Ahmed M Mostafa
- Department of Obstetrics and Gynecology, The University of Texas Medical Branch, Galveston, TX, USA; Department of Biochemistry, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Nadia M Hamdy
- Department of Biochemistry, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Hala O El-Mesallamy
- Department of Biochemistry, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Sherif Z Abdel-Rahman
- Department of Obstetrics and Gynecology, The University of Texas Medical Branch, Galveston, TX, USA.
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Helmy MM, Helmy MW, El-Mas MM. Additive Renoprotection by Pioglitazone and Fenofibrate against Inflammatory, Oxidative and Apoptotic Manifestations of Cisplatin Nephrotoxicity: Modulation by PPARs. PLoS One 2015; 10:e0142303. [PMID: 26536032 PMCID: PMC4633146 DOI: 10.1371/journal.pone.0142303] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 10/19/2015] [Indexed: 01/06/2023] Open
Abstract
Nephrotoxicity is a major side effect for the antineoplastic drug cisplatin. Here, we employed pharmacological, biochemical, and molecular studies to investigate the role of peroxisome proliferator-activated receptors (PPARs) in cisplatin nephrotoxicity. Rats were treated with a single i.p. dose of cisplatin (5 mg/kg) alone or combined with pioglitazone (PPARγ agonist), fenofibrate (PPARα agonist), pioglitazone plus fenofibrate, or thalidomide (Tumor necrosis factor-α inhibitor; TNF-α). Cisplatin nephrotoxicity was evidenced by rises in renal indices of functional (blood urea nitrogen, BUN, and creatinine), inflammatory (TNF-α, interleukin 6, IL-6), oxidative (increased malondialdehyde, MDA, and decreased superoxide dismutase, SOD and nitric oxide metabolites, NOx), apoptotic (caspase 3), and histological (glomerular atrophy, acute tubular necrosis and vacuolation) profiles. Cisplatin effects were partly abolished upon concurrent exposure to pioglitazone, fenofibrate, or thalidomide; more renoprotection was observed in rats treated with pioglitazaone plus fenofibrate. Immunostaining showed that renal expressions of PPARα and PPARγ were reduced by cisplatin and restored to vehicle-treated values after simultaneous treatment with pioglitazone or fenofibrate. Fenofibrate or pioglitazone renoprotection remained unaltered after concurrent blockade of PPARα (GW6471) and PPARγ (GW9662), respectively. To complement the rat studies, we also report that in human embryonic kidney cells (HEK293 cells), increases caused by cisplatin in inflammatory, apoptotic, and oxidative biomarkers were (i) partly improved after exposure to pioglitazone, fenofibrate, or thalidomide, and (ii) completely disappeared in cells treated with a combination of all three drugs. These data establish that the combined use of pioglitazone and fenofibrate additively improved manifestations of cisplatin nephrotoxicity through perhaps GW6471/GW9662-insensitive mechanisms.
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Affiliation(s)
- Mai M Helmy
- Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Maged W Helmy
- Pharmacology and Toxicology, Faculty of Pharmacy, Damanhour University, Damanhour, Egypt
| | - Mahmoud M El-Mas
- Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
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Huang W, Mehta KD. Modulation of Hepatic Protein Kinase Cβ Expression in Metabolic Adaptation to a Lithogenic Diet. Cell Mol Gastroenterol Hepatol 2015; 1:395-405. [PMID: 28210689 PMCID: PMC5301293 DOI: 10.1016/j.jcmgh.2015.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 05/08/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Dietary factors are likely an important determinant of gallstone development, and difficulty in adapting to lithogenic diets may predispose individuals to gallstone formation. Identification of the critical early diet-dependent metabolic markers of adaptability is urgently needed to prevent gallstone development. We focus on the interaction between diet and genes, and the resulting potential to influence gallstone risk by dietary modification. METHODS Expression levels of hepatic protein kinase C (PKC) isoforms were determined in lithogenic diet-fed mice, and the relationship of hepatic cholesterol content and PKCβ expression and the effect of hepatic PKCβ overexpression on intracellular signaling pathways were analyzed. RESULTS Lithogenic diet feeding resulted in a striking induction of hepatic PKCβ and PKCδ mRNA and protein levels, which preceded the appearance of biliary cholesterol crystals. Unlike PKCβ deficiency, global PKCδ deficiency did not influence lithogenic diet-induced gallstone formation. Interestingly, a deficiency of apolipoprotein E abrogated the diet-induced hepatic PKCβ expression, whereas a deficiency of liver X receptor-α further potentiated the induction, suggesting a potential link between the degree of hepatic PKCβ induction and the intracellular cholesterol content. Furthermore, our results suggest that PKCβ is a physiologic repressor of ileum basal fibroblast growth factor 15 (FGF15) expression and activity of hepatic proto-oncogene serine/threonine-protein kinase Raf-1/mitogen-activated protein (MAP) kinase kinase/extracellular signal-regulated kinases 1/2 (Raf-1/MEK/ERK1/2) cascade proteins, and the complex interactions between these pathways may determine the degree of hepatic ERK1/2 activation, a potent suppressor of cholesterol 7α-hydroxylase and sterol 12α-hydroxylase expression. We found that PKCβ regulated Raf-1 activity by modulating the inhibitory Raf-1Ser259 phosphorylation. CONCLUSIONS Our results demonstrate a novel interaction between the hepatic PKCβ/Raf-1 regulatory axis and ileum PKCβ/FGF15/ERK axis, which could modulate the bile lithogenecity of dietary lipids. The data presented are consistent with a two-pronged mechanism by which intestine and liver PKCβ signaling converges on the liver ERK1/2 pathway to control the hepatic adaptive response to a lithogenic diet. Elucidating the impact and the underlying mechanism(s) of PKCβ action could help us understand how different types of dietary fat modify the risk of gallstone formation, information that could help to identify novel targets for therapeutic approaches to combat this disease.
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Key Words
- Akt, protein kinase B
- ApoE, apolipoprotein E
- Cyp7a1, cholesterol 7α-hydroxylase
- Cyp8b1, sterol 12α-hydroxylase
- ERK1/2, extracellular signal regulated kinase-1/2
- FGF15, fibroblast growth factor 15
- FXR, farnesoid X receptor
- GSK-3, glycogen synthase kinase-3
- Hepatic Cholesterol Metabolism
- JNK, c-Jun N-terminal kinase
- LDL, low-density lipoprotein
- LXR, liver X receptor
- Lithogenic Diet
- MEK, mitogen-activated protein (MAP) kinase kinase
- MMLD, modified milk fat lithogenic diet
- PKCβ, protein kinase C isoform β
- Protein Kinase Cβ
- Raf-1, Raf-1 hepatic proto-oncogene serine/threonine-protein kinase
- SREBP, sterol response element-binding protein
- Signal Transduction
- WT, wild type
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Affiliation(s)
| | - Kamal D. Mehta
- Correspondence Address correspondence to: Kamal D. Mehta, PhD, Department of Biological Chemistry and Pharmacology, Ohio State University College of Medicine, 464 Hamilton Hall, 1645 Neil Avenue, Columbus, Ohio 43210. fax: 614-292-4118.
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Guo Z, Kang S, Zhu X, Xia J, Wu Q, Wang S, Xie W, Zhang Y. Down-regulation of a novel ABC transporter gene (Pxwhite) is associated with Cry1Ac resistance in the diamondback moth, Plutella xylostella (L.). INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2015; 59:30-40. [PMID: 25636859 DOI: 10.1016/j.ibmb.2015.01.009] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 01/09/2015] [Accepted: 01/16/2015] [Indexed: 06/04/2023]
Abstract
Biopesticides or transgenic crops based on Cry toxins from the soil bacterium Bacillus thuringiensis (Bt) effectively control agricultural insect pests. The sustainable use of Bt biopesticides and Bt crops is threatened, however, by the development of Cry resistance in the target pests. The diamondback moth, Plutella xylostella (L.), is the first pest that developed resistance to a Bt biopesticide in the field, and a recent study has shown that the resistance of P. xylostella to Cry1Ac is caused by a mutation in an ATP-binding cassette (ABC) transporter gene (ABCC2). In this study, we report that down-regulation of a novel ABC transporter gene from ABCG subfamily (Pxwhite) is associated with Cry1Ac resistance in P. xylostella. The full-length cDNA sequence of Pxwhite was cloned and analyzed. Spatial-temporal expression detection revealed that Pxwhite was expressed in all tissues and developmental stages, and highest expressed in Malpighian tubule tissue and in egg stage. Sequence variation analysis of Pxwhite indicated the absence of constant non-synonymous mutations between susceptible and resistant strains, whereas midgut transcript analysis showed that Pxwhite was remarkably reduced in all resistant strains and further reduced when larvae of the moderately resistant SZ-R strain were subjected to selection with Cry1Ac toxin. Furthermore, RNA interference (RNAi)-mediated suppression of Pxwhite gene expression significantly reduced larval susceptibility to Cry1Ac toxin, and genetic linkage analysis confirmed that down-regulation of Pxwhite gene is tightly linked to Cry1Ac resistance in P. xylostella. To our knowledge, this is the first report indicating that Pxwhite gene is involved in Cry1Ac resistance in P. xylostella.
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Affiliation(s)
- Zhaojiang Guo
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Shi Kang
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Xun Zhu
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Jixing Xia
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Qingjun Wu
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Shaoli Wang
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Wen Xie
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Youjun Zhang
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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Ezetimibe suppresses cholesterol accumulation in lipid-loaded vascular smooth muscle cells in vitro via MAPK signaling. Acta Pharmacol Sin 2014; 35:1129-36. [PMID: 25087996 DOI: 10.1038/aps.2014.10] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 07/14/2014] [Indexed: 01/30/2023] Open
Abstract
AIM To investigate the mechanisms of anti-atherosclerotic action of ezetimibe in rat vascular smooth muscle cells (VSMCs) in vitro. METHODS VSMCs of SD rats were cultured in the presence of Chol:MβCD (10 μg/mL) for 72 h, and intracellular lipid droplets and cholesterol levels were evaluated using Oil Red O staining, HPLC and Enzymatic Fluorescence Assay, respectively. The expression of caveolin-1, sterol response element-binding protein-1 (SREBP-1) and ERK1/2 were analyzed using Western blot assays. Translocation of SREBP-1 and ERK1/2 was detected with immunofluorescence. RESULTS Treatment with Chol:MβCD dramatically increased the cellular levels of total cholesterol (TC), cholesterol ester (CE) and free cholesterol (FC) in VSMCs, which led to the formation of foam cells. Furthermore, Chol:MβCD treatment significantly decreased the expression of caveolin-1, and stimulated the expression and nuclear translocation of SREBP-1 in VSMCs. Co-treatment with ezetimibe (3 μmol/L) significantly decreased the cellular levels of TC, CE and FC, which was accompanied by elevation of caveolin-1 expression, and by a reduction of SREBP-1 expression and nuclear translocation. Co-treatment with ezetimibe dose-dependently decreased the expression of phosphor-ERK1/2 (p-ERK1/2) in VSMCs. The ERK1/2 inhibitor PD98059 (50 μmol/L) altered the cholesterol level and the expression of p-ERK1/2, SREBP-1 and caveolin-1 in the same manner as ezetimibe did. CONCLUSION Ezetimibe suppresses cholesterol accumulation in rat VSMCs in vitro by regulating SREBP-1 and caveolin-1 expression, possibly via the MAPK signaling pathway.
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32
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Majdalawieh AF, Ro HS. Sesamol and sesame (Sesamum indicum) oil enhance macrophage cholesterol efflux via up-regulation of PPARγ1 and LXRα transcriptional activity in a MAPK-dependent manner. Eur J Nutr 2014; 54:691-700. [DOI: 10.1007/s00394-014-0747-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 07/23/2014] [Indexed: 02/08/2023]
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Lin XL, He XL, Zeng JF, Zhang H, Zhao Y, Tan JK, Wang Z. FGF21 Increases Cholesterol Efflux by Upregulating ABCA1 Through the ERK1/2–PPARγ–LXRα Pathway in THP1 Macrophage-Derived Foam Cells. DNA Cell Biol 2014; 33:514-21. [PMID: 24735204 DOI: 10.1089/dna.2013.2290] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Xiao-Long Lin
- Key Laboratory for Arteriosclerology of Hunan Province, Institute of Cardiovascular Disease, University of South China, Hengyang, China
- Pathology Department, The Third People's Hospital of Huizhou, Guangdong Huizhou, China
| | - Xing-Lan He
- Key Laboratory for Arteriosclerology of Hunan Province, Institute of Cardiovascular Disease, University of South China, Hengyang, China
| | - Jun-Fa Zeng
- The Second Affiliated Hospital of the University of South China, Hengyang, China
| | - Hai Zhang
- Key Laboratory for Arteriosclerology of Hunan Province, Institute of Cardiovascular Disease, University of South China, Hengyang, China
| | - Yue Zhao
- The First Affiliated Hospital of the University of South China, Hengyang, China
| | - Jian-Kai Tan
- The First Affiliated Hospital of the University of South China, Hengyang, China
| | - Zuo Wang
- Key Laboratory for Arteriosclerology of Hunan Province, Institute of Cardiovascular Disease, University of South China, Hengyang, China
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Nicod N, Parker RS. Vitamin E secretion by Caco-2 monolayers to APOA1, but not to HDL, is vitamer selective. J Nutr 2013; 143:1565-72. [PMID: 23946344 PMCID: PMC3771812 DOI: 10.3945/jn.113.176834] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The aim of this study was to characterize the pathways of basolateral secretion of common dietary tocopherols from polarized Caco-2 monolayers, a model of intestinal absorption. Given differences in structure and physical properties, we hypothesized that secretion may differ between different forms of vitamin E, thus potentially contribute to the selectivity seen in vivo. Monolayers were incubated apically and simultaneously with 10 μmol/L α-, γ-, and δ-tocopherol (1:1:1) in lipid micelles. Treatment with the microsomal triglyceride transfer protein inhibitor BMS201038 revealed that the triglyceride-rich particle secretory pathway (apolipoprotein B-dependent pathway) accounted for ~ 80% of total tocopherol secretion, without selectivity among the three forms of vitamin E. Apolipoprotein B-independent secretion of tocopherols (and cholesterol) was greatly enhanced by the liver X receptor agonist T0901317. T0901317 induced ATP-binding cassette transporter A1 (ABCA1) protein expression and basolateral secretion of tocopherols to apolipoprotein A1. ABCA1-dependent secretion demonstrated vitamer selectivity such that efficiency of secretion of α- and γ-tocopherols exceeded that of δ-tocopherol. Basal addition of HDL stimulated vitamin E secretion but without selectivity among the three forms, whereas LDL had no effect. Basal addition of scavenger receptor class B member I (SR-BI) blocking antibody, which inhibits the interaction between SR-BI and HDL, increased basal accumulation of all tocopherols, demonstrating a role for SR-BI in cellular re-uptake of secreted vitamin E. These findings demonstrated that vitamin E and cholesterol utilize common pathways of secretion and that secretion via the ABCA1 pathway favors certain forms of vitamin E.
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