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Drzymała A. The Functions of SARS-CoV-2 Receptors in Diabetes-Related Severe COVID-19. Int J Mol Sci 2024; 25:9635. [PMID: 39273582 PMCID: PMC11394807 DOI: 10.3390/ijms25179635] [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: 08/01/2024] [Revised: 08/25/2024] [Accepted: 09/01/2024] [Indexed: 09/15/2024] Open
Abstract
Angiotensin-converting enzyme 2 (ACE2) is considered a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor of high importance, but due to its non-ubiquitous expression, studies of other proteins that may participate in virus internalisation have been undertaken. To date, many alternative receptors have been discovered. Their functioning may provide an explanation for some of the events observed in severe COVID-19 that cannot be directly explained by the model in which ACE2 constitutes the central point of infection. Diabetes mellitus type 2 (T2D) can induce severe COVID-19 development. Although many mechanisms associated with ACE2 can lead to increased SARS-CoV-2 virulence in diabetes, proteins such as basigin (CD147), glucose-regulated protein 78 kDa (GRP78), cluster of differentiation 4 (CD4), transferrin receptor (TfR), integrins α5β1/αvβ3, or ACE2 co-receptors neuropilin 2 (NRP2), vimentin, and even syalilated gangliosides may also be responsible for worsening the COVID-19 course. On the other hand, some others may play protective roles. Understanding how diabetes-associated mechanisms can induce severe COVID-19 via modification of virus receptor functioning needs further extensive studies.
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Affiliation(s)
- Adam Drzymała
- Department of Clinical Biochemistry and Laboratory Diagnostics, Institute of Medical Sciences, University of Opole, Oleska 48, 45-052 Opole, Poland
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2
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Yoopum S, Wongmanee N, Rojanaverawong W, Rattanapunya S, Sumsakul W, Hanchang W. Mango (Mangifera indica L.) seed kernel extract suppresses hyperglycemia by modulating pancreatic β cell apoptosis and dysfunction and hepatic glucose metabolism in diabetic rats. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:123286-123308. [PMID: 37981611 DOI: 10.1007/s11356-023-31066-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 11/12/2023] [Indexed: 11/21/2023]
Abstract
This study investigated the anti-hyperglycemic action of mango seed kernel extract (MKE) and various mechanisms involved in its actions to improve pancreatic β cells and hepatic carbohydrate metabolism in diabetic rats. An intraperitoneal injection of 60 mg/kg of streptozotocin (STZ) followed by 30 consecutive days of treatment with MKE (250, 500, and 1000 mg/kg body weight) was used to establish a study group of diabetic rats. Using liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) for identification, 26 chemical compounds were found in MKE and the high-performance liquid chromatography (HPLC) analysis of the MKE also revealed the existence of mangiferin, gallic acid, and quercetin. The results confirmed that in each diabetes-affected rat, MKE mitigated the heightened levels of fasting blood glucose, diabetic symptoms, glucose intolerance, total cholesterol (TC), and low-density lipoprotein-cholesterol (LDL-C). As demonstrated by a remarkable increment in serum and pancreatic insulin, the diabetic pancreatic β cell function was potentiated by treating with MKE. The effect of MKE on diabetic pancreatic apoptosis clearly reduced the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells, which was related to diminished levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and Bax and an increase in Bcl-xL protein expression. Furthermore, diabetes-induced liver damage was clearly ameliorated along with a notable reduction in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and abnormal liver histology. By enhancing anti-oxidant superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities, MKE alleviated diabetes-induced pancreatic and liver oxidative damage, as demonstrated by diminished levels of malondialdehyde. In minimizing the expression levels of glucose 6-phosphatase and phosphoenolpyruvate carboxykinase-1 proteins in the diabetic liver, MKE also enhanced glycogen content and hexokinase activity. Collectively, these findings indicate that by suppressing oxidative and inflammatory processes, MKE exerts a potent anti-hyperglycemic activity in diabetic rats which serve to protect pancreatic β cell apoptosis, enhance their function, and improve hepatic glucose metabolism.
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Affiliation(s)
- Sasiwat Yoopum
- Department of Physiology, Faculty of Medical Science, Naresuan University, Phitsanulok, 65000, Thailand
| | - Navinee Wongmanee
- Department of Physiology, Faculty of Medical Science, Naresuan University, Phitsanulok, 65000, Thailand
| | - Worarat Rojanaverawong
- Department of Physiology, Faculty of Medical Science, Naresuan University, Phitsanulok, 65000, Thailand
| | - Siwalee Rattanapunya
- Public Health Department, Science and Technology Faculty, Chiang Mai Rajabhat University, Chiang Mai, 50300, Thailand
| | - Wiriyaporn Sumsakul
- Expert Centre of Innovative Herbal Products, Institute of Scientific and Technology Research, Pathum Thani, 12120, Thailand
| | - Wanthanee Hanchang
- Department of Physiology, Faculty of Medical Science, Naresuan University, Phitsanulok, 65000, Thailand.
- Centre of Excellence in Medical Biotechnology, Naresuan University, Phitsanulok, 65000, Thailand.
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3
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Evangelatov A, Georgiev G, Arabadjiev B, Pankov S, Krastev P, Momchilova A, Pankov R. Hyperglycemia attenuates fibroblast contractility via suppression of TβRII receptor modulated α-smooth muscle actin expression. BIOTECHNOL BIOTEC EQ 2022. [DOI: 10.1080/13102818.2022.2041486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- Alexandar Evangelatov
- Department of Cytology, Histology and Embryology, Faculty of Biology, Sofia University “St. Kliment Ohridski”, Sofia, Bulgaria
| | - Georgi Georgiev
- Department of Cytology, Histology and Embryology, Faculty of Biology, Sofia University “St. Kliment Ohridski”, Sofia, Bulgaria
| | - Borislav Arabadjiev
- Department of Cytology, Histology and Embryology, Faculty of Biology, Sofia University “St. Kliment Ohridski”, Sofia, Bulgaria
| | - Stefan Pankov
- Department of Lipid-Protein Interactions, Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Plamen Krastev
- Cardiology Clinic, University Hospital “St. Ekaterina”, Sofia, Bulgaria
| | - Albena Momchilova
- Department of Lipid-Protein Interactions, Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Roumen Pankov
- Department of Cytology, Histology and Embryology, Faculty of Biology, Sofia University “St. Kliment Ohridski”, Sofia, Bulgaria
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Powers HR, Sahoo D. SR-B1's Next Top Model: Structural Perspectives on the Functions of the HDL Receptor. Curr Atheroscler Rep 2022; 24:277-288. [PMID: 35107765 PMCID: PMC8809234 DOI: 10.1007/s11883-022-01001-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2021] [Indexed: 02/04/2023]
Abstract
PURPOSE OF REVIEW The binding of high-density lipoprotein (HDL) to its primary receptor, scavenger receptor class B type 1 (SR-B1), is critical for lowering plasma cholesterol levels and reducing cardiovascular disease risk. This review provides novel insights into how the structural elements of SR-B1 drive efficient function with an emphasis on bidirectional cholesterol transport. RECENT FINDINGS We have generated a new homology model of full-length human SR-B1 based on the recent resolution of the partial structures of other class B scavenger receptors. Interrogating this model against previously published observations allows us to generate structurally informed hypotheses about SR-B1's ability to mediate HDL-cholesterol (HDL-C) transport. Furthermore, we provide a structural perspective as to why human variants of SR-B1 may result in impaired HDL-C clearance. A comprehensive understanding of SR-B1's structure-function relationships is critical to the development of therapeutic agents targeting SR-B1 and modulating cardiovascular disease risk.
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Affiliation(s)
- Hayley R. Powers
- grid.30760.320000 0001 2111 8460Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI USA
| | - Daisy Sahoo
- grid.30760.320000 0001 2111 8460Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI USA ,grid.30760.320000 0001 2111 8460Department of Medicine, Division of Endocrinology & Molecular Medicine, Medical College of Wisconsin, Milwaukee, WI USA ,grid.30760.320000 0001 2111 8460Cardiovascular Center, H4930 Health Research Center, Medical College of Wisconsin, 8701 W. Watertown Plank Road, Milwaukee, WI 53226 USA
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Dong T, Sato S, Lyu J, Imachi H, Kobayashi T, Fukunaga K, Saheki T, Iwama H, Zhang G, Murao K. Treatment with 2-methoxyestradiol increases endothelial nitric oxide synthase activity via scavenger receptor class BI in human umbilical vein endothelial cells. Mol Hum Reprod 2021; 26:441-451. [PMID: 32333783 DOI: 10.1093/molehr/gaaa028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 04/08/2020] [Accepted: 04/19/2020] [Indexed: 12/24/2022] Open
Abstract
Concentrations of 2-methoxyestradiol (2ME2), a principal metabolite of estradiol, are significantly lower in women with severe preeclampsia. Nitric oxide (NO) released by endothelial nitric oxide synthase (eNOS) plays an important role in regulating cardiovascular homeostasis. Importantly, high-density lipoprotein (HDL) stimulates eNOS activity via endothelial human scavenger receptor class B type I (hSR-BI/CLA-1). Here, we aimed to determine the effect of 2ME2 on hSR-BI/CLA-1 expression in human umbilical vein endothelial cells (HUVECs). hSR-BI/CLA-1 expression was measured by real-time PCR, western blotting and reporter gene assays; eNOS activity was assessed by the measurement of eNOS phosphorylation. Both the mRNA and protein concentrations of hSR-BI/CLA-1 were significantly increased by 2ME2 in HUVECs. 2ME2 also dose-dependently increased the transcriptional activity of the hSR-BI/CLA-1 promoter. The effect of 2ME2 treatment on the promoter activity of hSR-BI/CLA-1 was abrogated by treatment with LY294002, a specific inhibitor of phosphatidylinositol 3-kinase, as was the increase in HDL-induced eNOS activation. Notably, constitutively active Akt increased the activity of the hSR-BI/CLA-1 promoter, whereas dominant-negative Akt abolished the effect of 2ME2 treatment on hSR-BI/CLA-1 promoter activity. The nuclear Sp1 protein concentration was significantly increased by exposure to 2ME2 and Sp1 overexpression increased the promoter activity of the hSR-BI/CLA gene. Furthermore, knockdown of Sp1 inhibited the effect of 2ME2 treatment on hSR-BI/CLA-1 protein expression. These results indicate that 2ME2 treatment increases HDL-dependent eNOS phosphorylation by upregulating endothelial hSR-BI/CLA-1 expression, suggesting that 2ME2 has a potential therapeutic value in the treatment of preeclampsia.
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Affiliation(s)
- Tao Dong
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
| | - Seisuke Sato
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
| | - Jingya Lyu
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
| | - Hitomi Imachi
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
| | - Toshihiro Kobayashi
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
| | - Kensaku Fukunaga
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
| | - Takanobu Saheki
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
| | - Hisakazu Iwama
- Life Science Research Center, Kagawa University, Kagawa 761-0793, Japan
| | - Guoxing Zhang
- Department of Physiology and Neuroscience, Medical College of Soochow University, Suzhou 215123, China
| | - Koji Murao
- Department of Endocrinology and Metabolism, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
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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: 92] [Impact Index Per Article: 30.7] [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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7
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Altered HDL metabolism in metabolic disorders: insights into the therapeutic potential of HDL. Clin Sci (Lond) 2020; 133:2221-2235. [PMID: 31722013 DOI: 10.1042/cs20190873] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/18/2019] [Accepted: 10/25/2019] [Indexed: 12/18/2022]
Abstract
Metabolic disorders are associated with an increased risk of cardiovascular disease (CVD), and are commonly characterized by a low plasma level of high-density lipoprotein cholesterol (HDL-C). Although cholesterol lowering medications reduce CVD risk in these patients, they often remain at increased risk of CVD. Therapeutic strategies that raise HDL-C levels and improve HDL function are a potential treatment option for reducing residual CVD risk in these individuals. Over the past decade, understanding of the metabolism and cardioprotective functions of HDLs has improved, with preclinical and clinical studies both indicating that the ability of HDLs to mediate reverse cholesterol transport, inhibit inflammation and reduce oxidation is impaired in metabolic disorders. These cardioprotective effects of HDLs are supported by the outcomes of epidemiological, cell and animal studies, but have not been confirmed in several recent clinical outcome trials of HDL-raising agents. Recent studies suggest that HDL function may be clinically more important than plasma levels of HDL-C. However, at least some of the cardioprotective functions of HDLs are lost in acute coronary syndrome and stable coronary artery disease patients. HDL dysfunction is also associated with metabolic abnormalities. This review is concerned with the impact of metabolic abnormalities, including dyslipidemia, obesity and Type 2 diabetes, on the metabolism and cardioprotective functions of HDLs.
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Wang D, Huang J, Gui T, Yang Y, Feng T, Tzvetkov NT, Xu T, Gai Z, Zhou Y, Zhang J, Atanasov AG. SR-BI as a target of natural products and its significance in cancer. Semin Cancer Biol 2020; 80:18-38. [PMID: 31935456 DOI: 10.1016/j.semcancer.2019.12.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/25/2019] [Accepted: 12/30/2019] [Indexed: 02/07/2023]
Abstract
Scavenger receptor class B type I (SR-BI) protein is an integral membrane glycoprotein. SR-BI is emerging as a multifunctional protein, which regulates autophagy, efferocytosis, cell survival and inflammation. It is well known that SR-BI plays a critical role in lipoprotein metabolism by mediating cholesteryl esters selective uptake and the bi-directional flux of free cholesterol. Recently, SR-BI has also been identified as a potential marker for cancer diagnosis, prognosis, or even a treatment target. Natural products are a promising source for the discovery of new drug leads. Multiple natural products were identified to regulate SR-BI protein expression. There are still a number of challenges in modulating SR-BI expression in cancer and in using natural products for modulation of such protein expression. In this review, our purpose is to discuss the relationship between SR-BI protein and cancer, and the molecular mechanisms regulating SR-BI expression, as well as to provide an overview of natural products that regulate SR-BI expression.
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Affiliation(s)
- Dongdong Wang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Jiansheng Huang
- Department of Medicine, Vanderbilt University Medical Center, 318 Preston Research Building, 2200 Pierce Avenue, Nashville, Tennessee, 37232, USA
| | - Ting Gui
- Key Laboratory of Traditional Chinese Medicine for Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China
| | - Yaxin Yang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Tingting Feng
- College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Huaxi university town, 550025, Guiyang, China
| | - Nikolay T Tzvetkov
- Department of Biochemical Pharmacology and Drug Design, Institute of Molecular Biology "Roumen Tsanev", Bulgarian Academy of Sciences, 21 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria
| | - Tao Xu
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Zhibo Gai
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Ying Zhou
- College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Huaxi university town, 550025, Guiyang, China.
| | - Jingjie Zhang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China.
| | - Atanas G Atanasov
- Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, 05-552, Jastrzębiec, Poland; Department of Pharmacognosy, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria; Institute of Neurobiology, Bulgarian Academy of Sciences, 23 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria; Ludwig Boltzmann Institute for Digital Health and Patient Safety, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
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Xu L, Zhang Y, Chen J, Xu Y. Thrombospondin-1: A Key Protein That Induces Fibrosis in Diabetic Complications. J Diabetes Res 2020; 2020:8043135. [PMID: 32626782 PMCID: PMC7306092 DOI: 10.1155/2020/8043135] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 05/12/2020] [Accepted: 05/19/2020] [Indexed: 12/23/2022] Open
Abstract
Fibrosis accompanies most common pathophysiological features of diabetes complications in different organs. It is characterized by an excessive accumulation of extracellular matrix (ECM) components, the response to which contributes to inevitable organ injury. The extracellular protein thrombospondin-1 (TSP-1), a kind of extracellular glycoprotein, is upregulated by the increased activity of some transcription factors and results in fibrosis by activating multiple pathways in diabetes. The results of studies from our team and other colleagues indicate that TSP-1 is associated with the pathological process leading to diabetic complications and is considered to be the most important factor in fibrosis. This review summarizes the molecular mechanism of increased TSP-1 induced by hyperglycemia and the role of TSP-1 in fibrosis during the development of diabetes complications.
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Affiliation(s)
- Linhao Xu
- Department of Cardiology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, 310006 Zhejiang, China
- School of Basic Medical Sciences & Forensic Medicine, Hangzhou Medical College, Hangzhou, 310053 Zhejiang, China
- Translational Medicine Research Center, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006 Zhejiang, China
| | - Yong Zhang
- Department of Urology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009 Zhejiang, China
| | - Jian Chen
- School of Basic Medical Sciences & Forensic Medicine, Hangzhou Medical College, Hangzhou, 310053 Zhejiang, China
| | - Yizhou Xu
- Department of Cardiology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, 310006 Zhejiang, China
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Wang D, Yang Y, Lei Y, Tzvetkov NT, Liu X, Yeung AWK, Xu S, Atanasov AG. Targeting Foam Cell Formation in Atherosclerosis: Therapeutic Potential of Natural Products. Pharmacol Rev 2019; 71:596-670. [PMID: 31554644 DOI: 10.1124/pr.118.017178] [Citation(s) in RCA: 114] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Foam cell formation and further accumulation in the subendothelial space of the vascular wall is a hallmark of atherosclerotic lesions. Targeting foam cell formation in the atherosclerotic lesions can be a promising approach to treat and prevent atherosclerosis. The formation of foam cells is determined by the balanced effects of three major interrelated biologic processes, including lipid uptake, cholesterol esterification, and cholesterol efflux. Natural products are a promising source for new lead structures. Multiple natural products and pharmaceutical agents can inhibit foam cell formation and thus exhibit antiatherosclerotic capacity by suppressing lipid uptake, cholesterol esterification, and/or promoting cholesterol ester hydrolysis and cholesterol efflux. This review summarizes recent findings on these three biologic processes and natural products with demonstrated potential to target such processes. Discussed also are potential future directions for studying the mechanisms of foam cell formation and the development of foam cell-targeted therapeutic strategies.
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Affiliation(s)
- Dongdong Wang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Yang Yang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Yingnan Lei
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Nikolay T Tzvetkov
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Xingde Liu
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Andy Wai Kan Yeung
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Suowen Xu
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Atanas G Atanasov
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
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11
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Huang Q, Liu Y, Yang Z, Xie Y, Mo Z. The Effects of Cholesterol Metabolism on Follicular Development and Ovarian Function. Curr Mol Med 2019; 19:719-730. [PMID: 31526349 DOI: 10.2174/1566524019666190916155004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 08/21/2019] [Accepted: 09/03/2019] [Indexed: 12/23/2022]
Abstract
Cholesterol is an important substrate for the synthesis of ovarian sex hormones and has an important influence on follicular development. The cholesterol in follicular fluid is mainly derived from plasma. High-density lipoprotein (HDL) and lowdensity lipoprotein (LDL) play important roles in ovarian cholesterol transport. The knockout of related receptors in the mammalian HDL and LDL pathways results in the reduction or absence of fertility, leading us to support the importance of cholesterol homeostasis in the ovary. However, little is known about ovarian cholesterol metabolism and the complex regulation of its homeostasis. Here, we reviewed the cholesterol metabolism in the ovary and speculated that regardless of the functioning of cholesterol metabolism in the system or the ovarian microenvironment, an imbalance in cholesterol homeostasis is likely to have an adverse effect on ovarian structure and function.
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Affiliation(s)
- Qin Huang
- Clinical Anatomy & Reproductive Medicine Application Institute, Department of Histology and Embryology, Hengyang Medical school, University of South China, Hengyang 421001, China
| | - Yannan Liu
- Nursing School, Hunan University of Medicine, Huaihua 418000, China
| | - Zhen Yang
- Clinical Anatomy & Reproductive Medicine Application Institute, Department of Histology and Embryology, Hengyang Medical school, University of South China, Hengyang 421001, China
| | - Yuanjie Xie
- Clinical Anatomy & Reproductive Medicine Application Institute, Department of Histology and Embryology, Hengyang Medical school, University of South China, Hengyang 421001, China
| | - Zhongcheng Mo
- Clinical Anatomy & Reproductive Medicine Application Institute, Department of Histology and Embryology, Hengyang Medical school, University of South China, Hengyang 421001, China
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12
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Tan JTM, Prosser HCG, Dunn LL, Vanags LZ, Ridiandries A, Tsatralis T, Lecce L, Clayton ZE, Yuen SCG, Robertson S, Lam YT, Celermajer DS, Ng MKC, Bursill CA. High-Density Lipoproteins Rescue Diabetes-Impaired Angiogenesis via Scavenger Receptor Class B Type I. Diabetes 2016; 65:3091-103. [PMID: 27284113 DOI: 10.2337/db15-1668] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 05/18/2016] [Indexed: 11/13/2022]
Abstract
Disordered neovascularization and impaired wound healing are important contributors to diabetic vascular complications. We recently showed that high-density lipoproteins (HDLs) enhance ischemia-mediated neovascularization, and mounting evidence suggests HDL have antidiabetic properties. We therefore hypothesized that HDL rescue diabetes-impaired neovascularization. Streptozotocin-induced diabetic mice had reduced blood flow recovery and neovessel formation in a hindlimb ischemia model compared with nondiabetic mice. Reconstituted HDL (rHDL) infusions in diabetic mice restored blood flow recovery and capillary density to nondiabetic levels. Topical rHDL application rescued diabetes-impaired wound closure, wound angiogenesis, and capillary density. In vitro, rHDL increased key mediators involved in hypoxia-inducible factor-1α (HIF-1α) stabilization, including the phosphoinositide 3-kinase/Akt pathway, Siah1, and Siah2, and suppressed the prolyl hydroxylases (PHD) 2 and PHD3. rHDL rescued high glucose-induced impairment of tubulogenesis and vascular endothelial growth factor (VEGF) A protein production, a finding associated with enhanced phosphorylation of proangiogenic mediators VEGF receptor 2 and endothelial nitric oxide synthase. Siah1/2 small interfering RNA knockdown confirmed the importance of HIF-1α stability in mediating rHDL action. Lentiviral short hairpin RNA knockdown of scavenger receptor class B type I (SR-BI) in vitro and SR-BI(-/-) diabetic mice in vivo attenuated rHDL rescue of diabetes-impaired angiogenesis, indicating a key role for SR-BI. These findings provide a greater understanding of the vascular biological effects of HDL, with potential therapeutic implications for diabetic vascular complications.
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MESH Headings
- Animals
- Blood Glucose/drug effects
- Cell Line
- Cholesterol/blood
- Cholesterol, HDL/blood
- Cholesterol, LDL/blood
- Diabetes Mellitus, Experimental
- Disease Models, Animal
- Humans
- Immunohistochemistry
- Lipoproteins, HDL/blood
- Lipoproteins, HDL/therapeutic use
- Male
- Mice
- Mice, Inbred C57BL
- Neovascularization, Physiologic/drug effects
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Regional Blood Flow/drug effects
- Regional Blood Flow/genetics
- Scavenger Receptors, Class B/genetics
- Scavenger Receptors, Class B/metabolism
- Ubiquitin-Protein Ligases/genetics
- Ubiquitin-Protein Ligases/metabolism
- Wound Healing/drug effects
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Affiliation(s)
- Joanne T M Tan
- The Heart Research Institute, Sydney, Australia Sydney Medical School, University of Sydney, Sydney, Australia
| | - Hamish C G Prosser
- The Heart Research Institute, Sydney, Australia Sydney Medical School, University of Sydney, Sydney, Australia
| | - Louise L Dunn
- The Heart Research Institute, Sydney, Australia Sydney Medical School, University of Sydney, Sydney, Australia
| | - Laura Z Vanags
- The Heart Research Institute, Sydney, Australia Sydney Medical School, University of Sydney, Sydney, Australia
| | - Anisyah Ridiandries
- The Heart Research Institute, Sydney, Australia Sydney Medical School, University of Sydney, Sydney, Australia
| | | | - Laura Lecce
- The Heart Research Institute, Sydney, Australia Sydney Medical School, University of Sydney, Sydney, Australia
| | - Zoë E Clayton
- The Heart Research Institute, Sydney, Australia Sydney Medical School, University of Sydney, Sydney, Australia
| | - Sui Ching G Yuen
- The Heart Research Institute, Sydney, Australia Sydney Medical School, University of Sydney, Sydney, Australia
| | - Stacy Robertson
- The Heart Research Institute, Sydney, Australia Sydney Medical School, University of Sydney, Sydney, Australia
| | - Yuen Ting Lam
- The Heart Research Institute, Sydney, Australia Sydney Medical School, University of Sydney, Sydney, Australia
| | - David S Celermajer
- The Heart Research Institute, Sydney, Australia Sydney Medical School, University of Sydney, Sydney, Australia Department of Cardiology, Royal Prince Alfred Hospital, Sydney, Australia
| | - Martin K C Ng
- The Heart Research Institute, Sydney, Australia Sydney Medical School, University of Sydney, Sydney, Australia Department of Cardiology, Royal Prince Alfred Hospital, Sydney, Australia
| | - Christina A Bursill
- The Heart Research Institute, Sydney, Australia Sydney Medical School, University of Sydney, Sydney, Australia
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13
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Yang F, Du Y, Zhang J, Jiang Z, Wang L, Hong B. Low-density lipoprotein upregulate SR-BI through Sp1 Ser702 phosphorylation in hepatic cells. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1861:1066-1075. [PMID: 27320013 DOI: 10.1016/j.bbalip.2016.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 05/04/2016] [Accepted: 06/10/2016] [Indexed: 01/25/2023]
Abstract
Scavenger receptor class B type I (SR-BI) is one of the key proteins in the process of reverse cholesterol transport (RCT), and its major function is to uptake high density lipoprotein (HDL) cholesterol from plasma into liver cells. The regulation of SR-BI expression is important for controlling serum lipid content and reducing the risks of cardiovascular diseases. Here we found that SR-BI expression was significantly increased by LDL in vivo and in vitro, and the transcription factor specific protein 1 (Sp1) plays a critical role in this process. Results from co-immunoprecipitation experiments indicate that the activation of SR-BI was associated with Sp1-recruited protein complexes in the promoter region of SR-BI, where histone acetyltransferase p300 was recruited and histone deacetylase HDAC1 was dismissed. As a result, histone acetylation increased, leading to activation of SR-BI transcription. With further investigation, we found that LDL phosphorylated Sp1 through ERK1/2 pathway, which affected Sp1 protein complexes formation in SR-BI promoter. Using mass spectrometry and site directed mutagenesis, a new Sp1 phosphorylation site Ser702 was defined to be associated with Sp1-HDAC1 interaction and may be important in SR-BI activation, shedding light on the knowledge of delicate mechanism of hepatic HDL receptor SR-BI gene modulation by LDL.
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Affiliation(s)
- Fan Yang
- Key Laboratory of Biotechnology of Antibiotics of Ministry of Health, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Tiantan Xili, Beijing 100050, China
| | - Yu Du
- Key Laboratory of Biotechnology of Antibiotics of Ministry of Health, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Tiantan Xili, Beijing 100050, China
| | - Jin Zhang
- Key Laboratory of Biotechnology of Antibiotics of Ministry of Health, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Tiantan Xili, Beijing 100050, China
| | - Zhibo Jiang
- Key Laboratory of Biotechnology of Antibiotics of Ministry of Health, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Tiantan Xili, Beijing 100050, China
| | - Li Wang
- Key Laboratory of Biotechnology of Antibiotics of Ministry of Health, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Tiantan Xili, Beijing 100050, China.
| | - Bin Hong
- Key Laboratory of Biotechnology of Antibiotics of Ministry of Health, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Tiantan Xili, Beijing 100050, China.
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14
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Seale LA, Gilman CL, Hashimoto AC, Ogawa-Wong AN, Berry MJ. Diet-induced obesity in the selenocysteine lyase knockout mouse. Antioxid Redox Signal 2015; 23:761-74. [PMID: 26192035 PMCID: PMC4589310 DOI: 10.1089/ars.2015.6277] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
AIMS Selenocysteine lyase (Scly) mediates selenocysteine decomposition. It was previously demonstrated that, upon adequate caloric intake (12% kcal fat) and selenium deficiency, disruption of Scly in mice leads to development of metabolic syndrome. In this study, we investigate the effect of a high-fat (45% kcal) selenium-adequate diet in Scly knockout (KO) mice on development of metabolic syndrome. Involvement of selenoproteins in energy metabolism after Scly disruption was also examined in vitro in the murine hepatoma cell line, Hepa1-6, following palmitate treatment. RESULTS Scly KO mice were more susceptible to diet-induced obesity than their wild-type counterparts after feeding a high-fat selenium-adequate diet. Scly KO mice had aggravated hyperinsulinemia, hypercholesterolemia, glucose, and insulin intolerance, but unchanged inflammatory cytokines and expression of most selenoproteins, except increased serum selenoprotein P (Sepp1). Scly KO mice also exhibited enhanced hepatic levels of pyruvate and enzymes involved in the regulation of pyruvate cycling, such as pyruvate carboxylase (Pcx) and pyruvate dehydrogenase (Pdh). However, in vitro silencing of Scly in Hepa1-6 cells led to diminished Sepp1 expression, and concomitant palmitate treatment decreased Pdh expression. INNOVATION The role of selenium in lipid metabolism is recognized, but specific selenium-dependent mechanisms leading to obesity are unclear. This study uncovers that Scly has a remarkable effect on obesity and metabolic syndrome development triggered by high-fat exposure, independent of the expression of most selenoproteins. CONCLUSION Diet-induced obesity in Scly KO mice is aggravated, with effects on pyruvate levels and consequent activation of energy metabolism independent of selenoprotein levels.
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Affiliation(s)
- Lucia A Seale
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa , Honolulu, Hawaii
| | - Christy L Gilman
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa , Honolulu, Hawaii
| | - Ann C Hashimoto
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa , Honolulu, Hawaii
| | - Ashley N Ogawa-Wong
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa , Honolulu, Hawaii
| | - Marla J Berry
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa , Honolulu, Hawaii
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15
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Hepatic scavenger receptor BI is associated with type 2 diabetes but unrelated to human and murine non-alcoholic fatty liver disease. Biochem Biophys Res Commun 2015; 467:377-82. [PMID: 26431876 DOI: 10.1016/j.bbrc.2015.09.149] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 09/27/2015] [Indexed: 02/07/2023]
Abstract
Scavenger receptor, class B type I (SR-BI) is a physiologically relevant regulator of high density lipoprotein (HDL) metabolism. Low HDL is a common feature of patients with non-alcoholic fatty liver disease (NAFLD). Here, hepatic SR-BI expression was analyzed in human and murine NAFLD. In primary human hepatocytes NAFLD relevant factors like inflammatory cytokines, lipopolysaccharide and TGF-β did not affect SR-BI protein. Similarly, oleate and palmitate had no effect. The adipokines chemerin, adiponectin, leptin and omentin did not regulate SR-BI expression. Accordingly, hepatic SR-BI was not changed in human and murine fatty liver and non-alcoholic steatohepatits. SR-BI was higher in type 2 diabetes patients but not in those with hypercholesterolemia. The current study indicates a minor if any role of SR-BI in human and murine NAFLD.
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16
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Chulsky S, Paland N, Lazarovich A, Fuhrman B. Urokinase-type plasminogen activator (uPA) decreases hepatic SR-BI expression and impairs HDL-mediated reverse cholesterol transport. Atherosclerosis 2014; 233:11-8. [DOI: 10.1016/j.atherosclerosis.2013.11.070] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/05/2013] [Accepted: 11/27/2013] [Indexed: 11/29/2022]
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Abstract
PURPOSE OF REVIEW Selective lipid uptake (SLU) is known to be a major pathway of lipoprotein cholesterol metabolism in experimental animals and humans, but remains poorly understood. This review provides a brief overview of SLU mediated by the HDL receptor scavenger receptor B-type I (SR-BI), and highlights several surprising new findings related to the impact of SLU pathways in cholesterol homeostasis. RECENT FINDINGS Under certain conditions, SR-BI-mediated SLU contributes to reverse cholesterol transport (RCT) independently of ABCG5/G8-mediated biliary cholesterol secretion, implying a novel trafficking mechanism. Hepatic SR-BI expression and RCT are decreased in diabetic mice. Farnesoid X receptor (FXR) and the microRNAs miR-185, miR-96 and miR-223 are emerging therapeutic targets for increasing SR-BI expression. SR-BI-independent selective cholesteryl ester uptake is a newly characterized pathway in macrophage foam cells. SUMMARY New findings underscore the importance of SR-BI-mediated SLU in hepatic SLU and RCT, while indicating that further investigation is needed to define SLU pathways, including SR-BI-independent macrophage selective cholesteryl ester uptake. The intracellular trafficking of cholesterol in these pathways appears to be critical to their normal function and is a major subject of ongoing studies.
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Affiliation(s)
- Jason M. Meyer
- Departments of Internal Medicine and Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, USA
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, Kentucky, USA
| | - Gregory A. Graf
- Department Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky, USA
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, Kentucky, USA
- Barnstable Brown Kentucky Diabetes and Obesity Center, University of Kentucky, Lexington, Kentucky, USA
| | - Deneys R. van der Westhuyzen
- Department of Veterans Affairs Medical Center, University of Kentucky, Lexington, Kentucky, USA
- Departments of Internal Medicine and Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, USA
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, Kentucky, USA
- Barnstable Brown Kentucky Diabetes and Obesity Center, University of Kentucky, Lexington, Kentucky, USA
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18
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Yang Y, Luo H, Cheng LX, Liu K. Inhibitory role for GABA in atherosclerosis. Med Hypotheses 2013; 81:803-4. [PMID: 24075593 DOI: 10.1016/j.mehy.2013.08.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 08/14/2013] [Accepted: 08/28/2013] [Indexed: 11/17/2022]
Abstract
γ-Aminobutyric acid (GABA), the classical inhibitory neurotransmitter in the nervous system, has a parallel inhibitory role in the immune system. It affects a variety of functional properties of the immune cells like monocyte migration, macrophage cholesterol efflux, regulatory T cell proliferation and inflammatory cytokine secretion. All of these are the main pathologic processes of atherosclerosis, a chronic inflammatory disease involving both innate and adaptive immune responses in the artery wall. Moreover, GABA has neuroprotective effects in brain ischemic injury, which is one of the serious complications of atherosclerosis. Therefore, we hypothesize GABA may be a prospect immune cell targeting therapy in atherosclerosis.
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Affiliation(s)
- Ying Yang
- Department of Cardiology, Union Hospital, Huazhong University of Science and Technology, Wuhan 430022, China
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19
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Kim GH, Park EC, Yun SH, Hong Y, Lee DG, Shin EY, Jung J, Kim YH, Lee KB, Jang IS, Lee ZW, Chung YH, Choi JS, Cheong C, Kim S, Kim SI. Proteomic and bioinformatic analysis of membrane proteome in type 2 diabetic mouse liver. Proteomics 2013; 13:1164-79. [PMID: 23349036 DOI: 10.1002/pmic.201200210] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 12/27/2012] [Accepted: 01/07/2013] [Indexed: 12/16/2022]
Abstract
Type 2 diabetes mellitus (T2DM) is the most prevalent and serious metabolic disease affecting people worldwide. T2DM results from insulin resistance of the liver, muscle, and adipose tissue. In this study, we used proteomic and bioinformatic methodologies to identify novel hepatic membrane proteins that are related to the development of hepatic insulin resistance, steatosis, and T2DM. Using FT-ICR MS, we identified 95 significantly differentially expressed proteins in the membrane fraction of normal and T2DM db/db mouse liver. These proteins are primarily involved in energy metabolism pathways, molecular transport, and cellular signaling, and many of them have not previously been reported in diabetic studies. Bioinformatic analysis revealed that 16 proteins may be related to the regulation of insulin signaling in the liver. In addition, six proteins are associated with energy stress-induced, nine proteins with inflammatory stress-induced, and 14 proteins with endoplasmic reticulum stress-induced hepatic insulin resistance. Moreover, we identified 19 proteins that may regulate hepatic insulin resistance in a c-Jun amino-terminal kinase-dependent manner. In addition, three proteins, 14-3-3 protein beta (YWHAB), Slc2a4 (GLUT4), and Dlg4 (PSD-95), are discovered by comprehensive bioinformatic analysis, which have correlations with several proteins identified by proteomics approach. The newly identified proteins in T2DM should provide additional insight into the development and pathophysiology of hepatic steatosis and insulin resistance, and they may serve as useful diagnostic markers and/or therapeutic targets for these diseases.
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Affiliation(s)
- Gun-Hwa Kim
- Division of Life Science, Korea Basic Science Institute, Daejeon, Republic of Korea
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Chandrasekaran K, Swaminathan K, Kumar SM, Clemens DL, Dey A. Increased oxidative stress and toxicity in ADH and CYP2E1 overexpressing human hepatoma VL-17A cells exposed to high glucose. Integr Biol (Camb) 2012; 4:550-63. [DOI: 10.1039/c2ib00155a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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21
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Valacchi G, Sticozzi C, Lim Y, Pecorelli A. Scavenger receptor class B type I: a multifunctional receptor. Ann N Y Acad Sci 2011; 1229:E1-7. [DOI: 10.1111/j.1749-6632.2011.06205.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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22
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Miyai Y, Murao K, Imachi H, Li J, Nishiuchi Y, Masugata H, Iwama H, Kushida Y, Ishida T, Haba R. Exendin-4 regulates the expression of the ATP-binding cassette transporter A1 via transcriptional factor PREB in the pancreatic β cell line. J Endocrinol Invest 2011; 34:e268-74. [PMID: 21521937 DOI: 10.3275/7683] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND PRL regulatory element-binding (PREB) protein is a transcription factor that regulates insulin promoter activity in the rat anterior pituitary. The PREB protein is expressed not only in the anterior pituitary but also in pancreatic β cells. Previously, we have reported that PREB plays an important role in glucose-mediated insulin gene expression in pancreatic β cells. The ATP-binding cassette transporter A1 (ABCA1) in pancreatic β cells influences insulin secretion and glucose homeostasis. Exendin-4 (Ex-4), a longacting agonist of the glucagon-like peptide 1, stimulates ABCA1 expression in pancreatic β cells. AIMS In this study, we examined the role played by PREB in Ex-4-induced ABCA1 expression in pancreatic β cells. MATERIAL/SUBJECTS AND METHODS PREB mRNA and protein expression were evaluated in pancreatic β cell line (INS-1 cells) treated with Ex-4 (10 nM). RESULTS Ex-4 stimulated PREB protein and mRNA expression in INS-1 cells. PREB stimulated the activity of the luciferase reporter protein that was under the control of the ABCA1 promoter. Chromatin immunoprecipitation assay showed that PREB mediates its transcriptional activity by directly binding to the ABCA1 promoter region. Finally, we used small interfering RNA to inhibit PREB expression in the cells and demonstrated that the knockdown of PREB expression attenuated the effects of Ex-4 on ABCA1 expression. CONCLUSION PREB mediates Ex-4-stimulated transcription of the ABCA1 gene in pancreatic β cells.
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Affiliation(s)
- Y Miyai
- Department of diagnostic pathology, Kagawa University, Miki-cho, Kita-gun, Kagawa, Japan
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23
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Cigarette smoke exposure causes changes in Scavenger Receptor B1 level and distribution in lung cells. Int J Biochem Cell Biol 2011; 43:1065-70. [DOI: 10.1016/j.biocel.2009.05.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 05/19/2009] [Accepted: 05/23/2009] [Indexed: 02/07/2023]
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Kent AP, Stylianou IM. Scavenger receptor class B member 1 protein: hepatic regulation and its effects on lipids, reverse cholesterol transport, and atherosclerosis. Hepat Med 2011; 3:29-44. [PMID: 24367219 PMCID: PMC3846864 DOI: 10.2147/hmer.s7860] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Scavenger receptor class B member 1 (SR-BI, also known as SCARB1) is the primary receptor for the selective uptake of cholesterol from high-density lipoprotein (HDL). SR-BI is present in several key tissues; however, its presence and function in the liver is deemed the most relevant for protection against atherosclerosis. Cholesterol is transferred from HDL via SR-BI to the liver, which ultimately results in the excretion of cholesterol via bile and feces in what is known as the reverse cholesterol transport pathway. Much of our knowledge of SR-BI hepatic function and regulation is derived from mouse models and in vitro characterization. Multiple independent regulatory mechanisms of SR-BI have been discovered that operate at the transcriptional and post-transcriptional levels. In this review we summarize the critical discoveries relating to hepatic SR-BI cholesterol metabolism, atherosclerosis, and regulation of SR-BI, as well as alternative functions that may indirectly affect atherosclerosis.
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Affiliation(s)
- Anthony P Kent
- Department of Medicine and Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Ioannis M Stylianou
- Department of Medicine and Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
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Sugiyama Y, Murao K, Imachi H, Sueyoshi N, Ishida T, Kameshita I. Calcium/calmodulin-dependent protein kinase IV involvement in the pathophysiology of glucotoxicity in rat pancreatic β-cells. Metabolism 2011; 60:145-53. [PMID: 20423744 DOI: 10.1016/j.metabol.2010.03.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 03/08/2010] [Accepted: 03/22/2010] [Indexed: 01/24/2023]
Abstract
Glucotoxicity is a critical component of the pathophysiology of type 2 diabetes mellitus; however, the molecular mechanisms of glucotoxicity are still not fully understood. We have attempted to determine the protein kinases involved in glucotoxicity in pancreatic β-cells by the use of a new technique. Using Multi-PK antibodies, which are capable of detecting a wide variety of protein kinases, we analyzed the protein kinase that correlated with insulin synthesis in INS-1 cells under glucotoxic conditions. When expression patterns of protein kinases in INS-1 cells were analyzed by Western blotting with Multi-PK antibodies, a kinase of 63 kd was significantly reduced concomitant with the decrease of insulin secretion under glucotoxic conditions. To identify the 63-kd kinase, we used a unique 2-dimensional gel electrophoretic technique and MicroRotofor (Bio-Rad Laboratories, Tokyo, Japan) electrophoresis. From the molecular size of a native kinase/cyanogen bromide fragment and pI value, the 63-kd protein kinase was deduced to be CaMKIV. This was confirmed by Western blotting analysis using anti-CaMKIV antibodies. The decreased CaMKIV levels under glucotoxic conditions recovered to original levels after changing the medium to a normal glucose concentration. Recombinant CaMKIV was degraded in a Ca²+-dependent manner by incubation with cell lysates from INS-1 cells under glucotoxic conditions, and degradation was protected by calpain inhibitor. Furthermore, CaMKIV was reduced in the pancreatic islets of diabetic Otsuka Long-Evans Tokushima fatty rats, whereas that of nondiabetic Long-Evans Tokushima Otsuka rats was not. This study suggests that the abnormal regulation of CaMKIV is a component of β-cell dysfunction caused by high glucose.
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Affiliation(s)
- Yasunori Sugiyama
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, 2393 Ikenobe Miki-cho, Kita-gun, Kagawa 761-0795, Japan
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Yamashita M, Tamasawa N, Matsuki K, Tanabe J, Murakami H, Matsui J, Suda T. Insulin suppresses HDL-mediated cholesterol efflux from macrophages through inhibition of neutral cholesteryl ester hydrolase and ATP-binding cassette transporter G1 expressions. J Atheroscler Thromb 2010; 17:1183-9. [PMID: 20733269 DOI: 10.5551/jat.4721] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
AIMS We studied the effect of insulin on HDL-mediated cholesterol efflux from macrophages. The potential involvement of cholesteryl ester hydrolysis and membrane cholesterol transport was also addressed. METHODS Human monocyte-derived THP-1 cells were developed into macrophages. Cholesterol efflux was measured by incubating macrophages, labeled with [³H]-cholesterol, with HDL for 24 h. The cells were treated with insulin (0-500 nM) for 30 min prior to the addition of HDL. To investigate the molecular mechanisms of the effect of insulin, the expressions of neutral cholesteryl ester hydrolase (nCEH) and ATP-binding cassette transporter (ABC) G1 were analyzed. RESULTS Insulin inhibited, in a concentration-dependent manner, HDL-mediated cholesterol efflux from macrophages. Insulin also inhibited the enzyme activity of nCEH and its mRNA and protein expression in cells. Insulin also suppressed the expressions of mRNA and protein for ABCG1. CONCLUSIONS Insulin inhibits HDL-mediated cholesterol efflux from macrophages, which may result from the suppression of nCEH and ABCG1 expressions. Our findings show part of the potential molecular mechanism of atherogenesis in type 2 diabetes with hyperinsulinemia.
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Affiliation(s)
- Maki Yamashita
- Department of Endocrinology and Metabolism, Hirosaki University Graduate School of Medicine, Aomori, Japan
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27
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Toll-like receptor 2 and class B scavenger receptor type I are required for bacterial uptake by trophoblast giant cells. Mol Immunol 2010; 47:1989-96. [PMID: 20471681 DOI: 10.1016/j.molimm.2010.04.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Revised: 04/23/2010] [Accepted: 04/23/2010] [Indexed: 01/06/2023]
Abstract
Trophoblast giant (TG) cells, components cells of the mouse placenta, exhibit phagocytic activity, and participate in the placental defense system by extracellular bacterial antigen uptake via phagocytosis. However, the bacterial uptake mechanisms by TG cells remain to be entirely understood. In an attempt to understand these mechanisms, in this study, we investigated the pattern recognition receptors (PRRs) involved in phagocytosis by TG cells. PRRs such as Toll-like receptors (TLRs) and scavenger receptors play a critical role in the immune response to bacterial pathogens. Among these, we selected TLR2 and class B scavenger receptor type I (SR-BI) and then evaluated their properties in TG cells. TLR2 and SR-BI expression is higher in TG cells than in trophoblast stem (TS) cells. Although interferon-gamma treatment activated bacterial uptake in a concentration-dependent manner, it did not induce TLR2 or SR-BI expression. Depletion of TLR2 and SR-BI by siRNA reduced the bacterial uptake ability of TG cells, which was also affected by treatment with the TLR2 agonist triacylated lipopeptide. These results suggested that the phagocytic activity of TG cells is mediated by both TLR2 and SR-BI.
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Chandrasekaran K, Swaminathan K, Chatterjee S, Dey A. Apoptosis in HepG2 cells exposed to high glucose. Toxicol In Vitro 2009; 24:387-96. [PMID: 19892008 DOI: 10.1016/j.tiv.2009.10.020] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 10/15/2009] [Accepted: 10/30/2009] [Indexed: 12/27/2022]
Abstract
Hyperglycemia which characterizes diabetes, leads to several abnormalities in the cellular pathways. We examined the toxicity of glucose in human hepatoma HepG2 cells. HepG2 cells when incubated with 50mM glucose for 72h showed altered morphology i.e. presence of detached and shrunken rounded cells. Glucose treated HepG2 cells also exhibited a significant decrease in viability. Caspase-3 activity and Annexin V staining were significantly increased in glucose treated HepG2 cells, suggesting an apoptotic mode of cell death. Glucose induced apoptosis in HepG2 cells was a consequence of increased oxidative stress as evidenced by the increased reactive oxygen species (ROS) level, lipid peroxidation, protein carbonyl and 3-nitrotyrosine adduct formation. The intracellular antioxidant glutathione was found to be increased in HepG2 cells treated with glucose, possibly to aid the cells to overcome the persistent oxidative stress elicited by glucose in HepG2 cells. N-Acetyl cysteine, a precursor of glutathione and an antioxidant was effective in reversing the morphological changes, increasing the viability, decreasing the ROS level and 4-hydroxynonenal and 3-nitrotyrosine adduct formation, thus validating the role of oxidative stress as a major mechanism for glucose induced apoptosis in HepG2 cells. These results suggest that glucose induces apoptosis in liver cells through increased oxidative stress.
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Affiliation(s)
- Karthikeyan Chandrasekaran
- Life Science Division, AU-KBC Research Centre, MIT Campus of Anna University, Chromepet, Chennai 600 044, India
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29
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Abstract
High-density lipoprotein (HDL) plays an important protective role against atherosclerosis, and the anti-atherogenic properties of HDL include the promotion of cellular cholesterol efflux and reverse cholesterol transport (RCT), as well as antioxidant, anti-inflammatory and anticoagulant effects. RCT is a complex pathway, which transports cholesterol from peripheral cells and tissues to the liver for its metabolism and biliary excretion. The major steps in the RCT pathway include the efflux of free cholesterol mediated by cholesterol transporters from cells to the main extracellular acceptor HDL, the conversion of free cholesterol to cholesteryl esters and the subsequent removal of cholesteryl ester in HDL by the liver. The efficiency of RCT is influenced by the mobilization of cellular lipids for efflux and the intravascular remodelling and kinetics of HDL metabolism. Despite the increased cardiovascular risk in people with type 2 diabetes, current knowledge on RCT in diabetes is limited. In this article, abnormalities in RCT in type 2 diabetes mellitus and therapeutic strategies targeting HDL and RCT will be reviewed.
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Affiliation(s)
- K C B Tan
- Department of Medicine, University of Hong Kong, Hong Kong.
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Ahmed RAM, Murao K, Imachi H, Yu X, Li J, Wong NCW, Ishida T. Human scavenger receptor class B type 1 is regulated by activators of peroxisome proliferators-activated receptor-gamma in hepatocytes. Endocrine 2009; 35:233-42. [PMID: 19156545 DOI: 10.1007/s12020-008-9142-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 11/04/2008] [Accepted: 12/15/2008] [Indexed: 11/28/2022]
Abstract
High-density lipoprotein (HDL) particles play a critical role in cholesterol metabolism. The hepatic scavenger receptor class B type I (SR-B1) binds HDL particles for mediating reverse cholesterol transport (RCT), thus lowering the risk of atherosclerosis. Thiazolidinediones (TZDs), known to have potent enhancing effects on insulin sensitivity, have been developed for the treatment of non-insulin-dependent diabetes mellitus. They are a high-affinity ligand for the peroxisome proliferator-activated receptor gamma (PPAR-gamma), which belongs to a nuclear receptor superfamily. In this study, we examined the effects of thiazolidinedione PPAR-gamma on hepatic SR-B1 gene expression in human hepatoma G2 cell-line (HepG2). Results showed that hepatic SR-B1 mRNA and protein were increased on exposure to thiazolidinediones. Transcriptional activity of human SR-B1 (hSR-B1) gene paralleled the endogenous expression of the gene and was dependent on the dose of thiazolidinediones. We investigated the influence on the promoter activity of vector expressing PPAR and retinoid X receptor (RXR), cotransfected into the HepG2 cells along with SR-B1 promoter-reporter gene constructs. PPAR-gamma and RXR sufficiently induced the SR-B1 promoter activity in the HepG2 cells. Chromatin immunoprecipitation (ChIP) assay confirmed the binding of the PPAR-gamma to the SR-B1 promoter region. The mutagenesis of this binding site abolished the ability of the thiazolidinediones or PPARs to stimulate promoter activity. Together, these results indicate that the stimulation of SR-B1 expression in the liver is mediated in part by activation of the PPAR-gamma and RXR, and raise the possibility that this stimulation using thiazolidinediones conditions provides a protective mechanism for accelerated atherosclerosis in diabetes mellitus.
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Affiliation(s)
- Rania Abdel Muneem Ahmed
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe Miki-cho, Kita-gun, Kagawa 761-0793, Japan
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31
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Murao K, Imachi H, Yu X, Cao WM, Muraoka T, Dobashi H, Hosomi N, Haba R, Iwama H, Ishida T. The transcriptional factor prolactin regulatory element-binding protein mediates the gene transcription of adrenal scavenger receptor class B type I via 3',5'-cyclic adenosine 5'-monophosphate. Endocrinology 2008; 149:6103-12. [PMID: 18755803 DOI: 10.1210/en.2008-0380] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Prolactin regulatory element-binding (PREB) protein is a transcription factor that regulates prolactin promoter activity in the rat anterior pituitary. The PREB protein is not only expressed in the anterior pituitary but also in the adrenal gland. However, the role of PREB in the adrenal gland is not clearly understood. Scavenger receptor class B type I (SR-BI) is a receptor for high-density lipoprotein that mediates the cellular uptake of high-density lipoprotein-cholesteryl ester and is a major route for cholesterol delivery to the steroidogenic pathway in the adrenal gland. In the present study, we have examined the role of PREB in regulating SR-BI. SR-BI expression was found to be regulated by cAMP, which stimulated the expression of PREB in a dose-dependent manner. Conversely, overexpression of PREB using a PREB-expressing adenovirus increased the expression of the SR-BI protein in the adrenocortical cell line Y-1. In addition, PREB induced the expression of the luciferase reporter protein that was under the control of the SR-BI promoter. EMSA showed that PREB mediates its transcriptional effect by binding to the PREB-responsive cis-element of the SR-BI promoter. Finally, we used small interfering RNA to inhibit PREB expression in the Y-1 cells and demonstrated that the knockdown of PREB expression attenuated the effects of cAMP on SR-BI expression. In summary, our data showed that in the adrenal gland, PREB regulates the transcription of the SR-BI gene via cAMP.
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Affiliation(s)
- Koji Murao
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe Miki-CHO, Kita-gun, Kagawa 761-0793, Japan.
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Ravid Z, Bendayan M, Delvin E, Sane AT, Elchebly M, Lafond J, Lambert M, Mailhot G, Levy E. Modulation of intestinal cholesterol absorption by high glucose levels: impact on cholesterol transporters, regulatory enzymes, and transcription factors. Am J Physiol Gastrointest Liver Physiol 2008; 295:G873-85. [PMID: 18772361 DOI: 10.1152/ajpgi.90376.2008] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Growing evidence suggests that the small intestine may contribute to excessive postprandial lipemia, which is highly prevalent in insulin-resistant/Type 2 diabetic individuals and substantially increases the risk of cardiovascular disease. The aim of the present study was to determine the role of high glucose levels on intestinal cholesterol absorption, cholesterol transporter expression, enzymes controlling cholesterol homeostasis, and the status of transcription factors. To this end, we employed highly differentiated and polarized cells (20 days of culture), plated on permeable polycarbonate filters. In the presence of [(14)C]cholesterol, glucose at 25 mM stimulated cholesterol uptake compared with Caco-2/15 cells supplemented with 5 mM glucose (P < 0.04). Because combination of 5 mM glucose with 20 mM of the structurally related mannitol or sorbitol did not change cholesterol uptake, we conclude that extracellular glucose concentration is uniquely involved in the regulation of intestinal cholesterol transport. The high concentration of glucose enhanced the protein expression of the critical cholesterol transporter NPC1L1 and that of CD36 (P < 0.02) and concomitantly decreased SR-BI protein mass (P < 0.02). No significant changes were observed in the protein expression of ABCA1 and ABCG8, which act as efflux pumps favoring cholesterol export out of absorptive cells. At the same time, 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity was decreased (P < 0.007), whereas ACAT activity remained unchanged. Finally, increases were noted in the transcription factors LXR-alpha, LXR-beta, PPAR-beta, and PPAR-gamma along with a drop in the protein expression of SREBP-2. Collectively, our data indicate that glucose at high concentrations may regulate intestinal cholesterol transport and metabolism in Caco-2/15 cells, thus suggesting a potential influence on the cholesterol absorption process in Type 2 diabetes.
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Affiliation(s)
- Z Ravid
- Research Centre, CHU-Sainte-Justine, 3175 Côte Ste-Catherine, Montréal, Québec, Canada H3T 1C5
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Zhou H, Tan KCB, Shiu SWM, Wong Y. Determinants of leukocyte adenosine triphosphate-binding cassette transporter G1 gene expression in type 2 diabetes mellitus. Metabolism 2008; 57:1135-40. [PMID: 18640393 DOI: 10.1016/j.metabol.2008.03.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Accepted: 03/17/2008] [Indexed: 11/26/2022]
Abstract
Cellular cholesterol efflux is regulated by cholesterol transporters including adenosine triphosphate-binding cassette transporter A1 (ABCA1), ABCG1, and scavenger receptor class B type I (SR-BI). We have investigated whether the expression of these transporters is affected by type 2 diabetes mellitus and the association with glycemic indexes and oxidized low-density lipoprotein (oxLDL). Messenger RNA of ABCA1, ABCG1, and SR-BI in peripheral monocytes was measured in 30 diabetic patients and 30 matched controls. Plasma oxLDL and advanced glycation end products (AGEs) were assayed by enzyme-linked immunosorbent assay. Cellular cholesterol efflux from monocytes to serum was determined in a subgroup chosen randomly. The expression of ABCG1 was decreased in diabetic patients (P < .05), whereas the levels of ABCA1 and SR-BI were comparable between the 2 groups. Fasting glucose, hemoglobin A(1c), AGEs, and oxLDL were all significantly increased in diabetic patients. There was an inverse correlation between serum AGEs and ABCG1 (r = -0.44, P < .05) that remained significant after adjusting for potential confounding factors. No associations between fasting glucose, hemoglobin A(1c), plasma lipids, or oxLDL and the expression of ABCG1, ABCA1, or SR-BI were found. Cholesterol efflux from monocytes to standard serum or autologous serum was significantly impaired in diabetic patients, and the reduction in efflux to autologous serum correlated with the expression of ABCG1 (r = 0.60, P < .05). The expression of ABCG1 in monocytes is reduced in type 2 diabetes mellitus and is partly related to serum AGEs concentration. The reduction in ABCG1 is associated with impairment in cholesterol efflux and may contribute to accelerated foam cell formation in diabetic patients.
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MESH Headings
- ATP Binding Cassette Transporter 1
- ATP Binding Cassette Transporter, Subfamily G, Member 1
- ATP-Binding Cassette Transporters/biosynthesis
- ATP-Binding Cassette Transporters/blood
- ATP-Binding Cassette Transporters/genetics
- Biological Transport
- Blood Glucose/metabolism
- Cholesterol/blood
- Diabetes Mellitus, Type 2/blood
- Diabetes Mellitus, Type 2/genetics
- Enzyme-Linked Immunosorbent Assay
- Female
- Gene Expression
- Glycated Hemoglobin/analysis
- Glycation End Products, Advanced/blood
- Humans
- Leukocytes, Mononuclear/metabolism
- Lipoproteins, LDL/blood
- Male
- Middle Aged
- RNA, Messenger/blood
- RNA, Messenger/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Scavenger Receptors, Class B/biosynthesis
- Scavenger Receptors, Class B/blood
- Scavenger Receptors, Class B/genetics
- Triglycerides/metabolism
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Affiliation(s)
- Huali Zhou
- Department of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong
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