1
|
Morvaridzadeh M, Zoubdane N, Heshmati J, Alami M, Berrougui H, Khalil A. High-Density Lipoprotein Metabolism and Function in Cardiovascular Diseases: What about Aging and Diet Effects? Nutrients 2024; 16:653. [PMID: 38474781 DOI: 10.3390/nu16050653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 02/20/2024] [Accepted: 02/23/2024] [Indexed: 03/14/2024] Open
Abstract
Cardiovascular diseases (CVDs) have become the leading global cause of mortality, prompting a heightened focus on identifying precise indicators for their assessment and treatment. In this perspective, the plasma levels of HDL have emerged as a pivotal focus, given the demonstrable correlation between plasma levels and cardiovascular events, rendering them a noteworthy biomarker. However, it is crucial to acknowledge that HDLs, while intricate, are not presently a direct therapeutic target, necessitating a more nuanced understanding of their dynamic remodeling throughout their life cycle. HDLs exhibit several anti-atherosclerotic properties that define their functionality. This functionality of HDLs, which is independent of their concentration, may be impaired in certain risk factors for CVD. Moreover, because HDLs are dynamic parameters, in which HDL particles present different atheroprotective properties, it remains difficult to interpret the association between HDL level and CVD risk. Besides the antioxidant and anti-inflammatory activities of HDLs, their capacity to mediate cholesterol efflux, a key metric of HDL functionality, represents the main anti-atherosclerotic property of HDL. In this review, we will discuss the HDL components and HDL structure that may affect their functionality and we will review the mechanism by which HDL mediates cholesterol efflux. We will give a brief examination of the effects of aging and diet on HDL structure and function.
Collapse
Affiliation(s)
- Mojgan Morvaridzadeh
- Department of Medicine, Geriatric Service, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 4N4, Canada
| | - Nada Zoubdane
- Department of Medicine, Geriatric Service, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 4N4, Canada
| | - Javad Heshmati
- Department of Medicine, Geriatric Service, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 4N4, Canada
| | - Mehdi Alami
- Department of Medicine, Geriatric Service, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 4N4, Canada
| | - Hicham Berrougui
- Department of Medicine, Geriatric Service, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 4N4, Canada
| | - Abdelouahed Khalil
- Department of Medicine, Geriatric Service, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 4N4, Canada
| |
Collapse
|
2
|
Iqbal F, Baker WS, Khan MI, Thukuntla S, McKinney KH, Abate N, Tuvdendorj D. Current and future therapies for addressing the effects of inflammation on HDL cholesterol metabolism. Br J Pharmacol 2017; 174:3986-4006. [PMID: 28326542 PMCID: PMC5660004 DOI: 10.1111/bph.13743] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/16/2017] [Accepted: 02/02/2017] [Indexed: 12/11/2022] Open
Abstract
Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide. Inflammatory processes arising from metabolic abnormalities are known to precipitate the development of CVD. Several metabolic and inflammatory markers have been proposed for predicting the progression of CVD, including high density lipoprotein cholesterol (HDL-C). For ~50 years, HDL-C has been considered as the atheroprotective 'good' cholesterol because of its strong inverse association with the progression of CVD. Thus, interventions to increase the concentration of HDL-C have been successfully tested in animals; however, clinical trials were unable to confirm the cardiovascular benefits of pharmaceutical interventions aimed at increasing HDL-C levels. Based on these data, the significance of HDL-C in the prevention of CVD has been called into question. Fundamental in vitro and animal studies suggest that HDL-C functionality, rather than HDL-C concentration, is important for the CVD-preventive qualities of HDL-C. Our current review of the literature positively demonstrates the negative impact of systemic and tissue (i.e. adipose tissue) inflammation in the healthy metabolism and function of HDL-C. Our survey indicates that HDL-C may be a good marker of adipose tissue health, independently of its atheroprotective associations. We summarize the current findings on the use of anti-inflammatory drugs to either prevent HDL-C clearance or improve the function and production of HDL-C particles. It is evident that the therapeutic agents currently available may not provide the optimal strategy for altering HDL-C metabolism and function, and thus, further research is required to supplement this mechanistic approach for preventing the progression of CVD. LINKED ARTICLES This article is part of a themed section on Targeting Inflammation to Reduce Cardiovascular Disease Risk. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.22/issuetoc and http://onlinelibrary.wiley.com/doi/10.1111/bcp.v82.4/issuetoc.
Collapse
Affiliation(s)
- Fatima Iqbal
- Division of Endocrinology, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTXUSA
| | - Wendy S Baker
- Division of Endocrinology, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTXUSA
| | - Madiha I Khan
- Division of Endocrinology, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTXUSA
| | - Shwetha Thukuntla
- Division of Endocrinology, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTXUSA
| | - Kevin H McKinney
- Division of Endocrinology, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTXUSA
| | - Nicola Abate
- Division of Endocrinology, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTXUSA
| | - Demidmaa Tuvdendorj
- Division of Endocrinology, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTXUSA
| |
Collapse
|
3
|
Pei Y, Chen X, Aboutouk D, Fuller MT, Dadoo O, Yu P, White EJ, Igdoura SA, Trigatti BL. SR-BI in bone marrow derived cells protects mice from diet induced coronary artery atherosclerosis and myocardial infarction. PLoS One 2013; 8:e72492. [PMID: 23967310 PMCID: PMC3742605 DOI: 10.1371/journal.pone.0072492] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 07/17/2013] [Indexed: 01/01/2023] Open
Abstract
SR-BI deficient mice that are also hypomorphic for apolipoprotein E expression develop diet induced occlusive coronary artery atherosclerosis, myocardial infarction and early death. To test the role of SR-BI in bone marrow derived cells, we used bone marrow transplantation to generate SR-BI-null; apoE-hypomorphic mice in which SR-BI expression was restored solely in bone marrow derived cells. SR-BI-null; apoE-hypomorphic mice were transplanted with SR-BI+/+apoE-hypomorphic, or control, autologous SR-BI-null; apoE-hypomorphic bone marrow. Four weeks later, mice were fed a high-fat, high-cholesterol, cholate-containing diet to induce coronary artery atherosclerosis. Mice transplanted with autologous bone marrow developed extensive aortic atherosclerosis and severe occlusive coronary artery atherosclerosis after 4 weeks of feeding. This was accompanied by myocardial fibrosis and increased heart weights. In contrast, restoration of SR-BI expression in bone marrow derived-cells reduced diet induced aortic and coronary artery atherosclerosis, myocardial fibrosis and the increase in heart weights in SR-BI-null; apoE-hypomorphic mice. Restoration of SR-BI in bone marrow derived cells did not, however, affect steady state lipoprotein cholesterol levels, but did reduce plasma levels of IL-6. Monocytes from SR-BI-null mice exhibited a greater capacity to bind to VCAM-1 and ICAM-1 than those from SR-BI+/+ mice. Furthermore, restoration of SR-BI expression in bone marrow derived cells attenuated monocyte recruitment into atherosclerotic plaques in mice fed high fat, high cholesterol cholate containing diet. These data demonstrate directly that SR-BI in bone marrow-derived cells protects against both aortic and CA atherosclerosis.
Collapse
Affiliation(s)
- Ying Pei
- Department of Biochemistry and Biomedical Sciences and Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Xing Chen
- Department of Biochemistry and Biomedical Sciences and Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Dina Aboutouk
- Department of Biochemistry and Biomedical Sciences and Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Mark T. Fuller
- Department of Biochemistry and Biomedical Sciences and Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Omid Dadoo
- Department of Biochemistry and Biomedical Sciences and Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Pei Yu
- Department of Biochemistry and Biomedical Sciences and Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Elizabeth J. White
- Department of Biology and Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Suleiman A. Igdoura
- Department of Biology and Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Bernardo L. Trigatti
- Department of Biochemistry and Biomedical Sciences and Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
- * E-mail:
| |
Collapse
|
4
|
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.
Collapse
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
| | | | | | | | | | | | | |
Collapse
|
5
|
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.
Collapse
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.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Murao K, Yu X, Imachi H, Cao WM, Chen K, Matsumoto K, Nishiuchi T, Wong NCW, Ishida T. Hyperglycemia suppresses hepatic scavenger receptor class B type I expression. Am J Physiol Endocrinol Metab 2008; 294:E78-87. [PMID: 17957039 DOI: 10.1152/ajpendo.00023.2007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Hyperglycemia is a major risk factor for atherosclerotic disease. Hepatic scavenger receptor class B type I (SR-BI) binds HDL particles that mediate reverse cholesterol transport and thus lowers the risk of atherosclerosis. Here we examined glucose regulation of SR-BI gene expression in both HepG2 cells and whole animals. Results showed that hepatic SR-BI mRNA, protein, and uptake of cholesterol from HDL were halved following 48 h of exposure to 22.4 vs. 5.6 mM glucose. As in the case of the cell culture model, hepatic expression of SR-BI was lower in diabetic rats than in euglycemic rats. Transcriptional activity of the human SR-BI promoter paralleled endogenous expression of the gene, and this activity was dependent upon the dose of glucose. Next, we used inhibitors of select signal transduction pathways to demonstrate that glucose suppression of SR-BI was sensitive to the p38 MAPK inhibitor. Expression of a constitutively active p38 MAPK inhibited SR-BI promoter activity in the presence or absence of glucose. A dominant-negative p38 MAPK abolished the inhibitory effect of glucose on promoter activity. Deletional analysis located a 50-bp fragment of the promoter that mediated the effects of glucose. Within this DNA fragment there were several specificity protein-1 (Sp1) binding sites, and cellular knockdown of Sp1 abrogated its suppression by glucose. Together, these results indicate that the glucose suppression of SR-B1 expression is partially mediated by the activation of the p38 MAPK-Sp1 pathway and raise the possibility that the inhibition of hepatic SR-BI expression under high-glucose conditions provides a mechanism for accelerated atherosclerosis in diabetics.
Collapse
Affiliation(s)
- Koji Murao
- Div. of Endocrinology and Metabolism, Dept. of Internal Medicine, Faculty of Medicine, Kagawa University, 1750-1, Miki-cho, Kita-gun, Kagawa, 761-0793, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Murao K, Imachi H, Cao W, Yu X, Li J, Yoshida K, Ahmed RAM, Matsumoto K, Nishiuchi T, Wong NCW, Ishida T. High-density lipoprotein is a potential growth factor for adrenocortical cells. Biochem Biophys Res Commun 2006; 344:226-32. [PMID: 16600185 DOI: 10.1016/j.bbrc.2006.03.131] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Accepted: 03/20/2006] [Indexed: 01/02/2023]
Abstract
The entry of cholesterol contained within high-density lipoprotein (HDL) into adrenocortical cells is mediated by a human homologue of SR-BI, CD36, and LIMPII Analogous-1 (CLA-1) and thus augmenting their growth. To address the role of CLA-1, we created a mutant mCLA that lacked the C-terminal tail. HDL CE selective uptake by cells carrying the mCLA-1 receptor was fully active and equivalent to those transfected with full-length CLA-1 (fCLA-1). Expression of mCLA inhibited the proliferation of an adrenocortical cell line and the incorporation of [(3)H]thymidine into the cells. This effect was sensitive to wortmannin, an inhibitor of phosphoinositide 3-kinase (PI3K). Our transcriptional studies revealed that the inhibitory action of mCLA required the transcriptional factor AP-1 and the effect of HDL on AP-1 activation was also abrogated by wortmannin. These findings raise the possibility that the inhibitors of the effects of HDL may be of therapeutic value for adrenocortical tumor.
Collapse
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, Japan.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Tosi MR, Tugnoli V. Cholesteryl esters in malignancy. Clin Chim Acta 2005; 359:27-45. [PMID: 15939411 DOI: 10.1016/j.cccn.2005.04.003] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2005] [Revised: 03/31/2005] [Accepted: 04/04/2005] [Indexed: 01/23/2023]
Abstract
Cholesteryl esters, formed by the esterification of cholesterol with long-chain fatty acids, on one hand, are the means by which cholesterol is transported through the blood by lipoproteins, on the other, the way cholesterol itself can be accumulated in the cells. Therefore, these important molecules play an active part in metabolic pathways that form the basis of cholesterol trafficking and homeostasis. The role of different regulatory mechanisms in cholesterol homeostasis in physiologic and neoplastic conditions with emphasis on intracellular content of cholesteryl esters is here reviewed. Numerous studies carried out on tumor cell lines, experimental tumors, and human tumors have shown an abnormal cholesterol metabolism that is reflected by an increase in intracellular cholesteryl esters due to an alteration in all the mechanisms that form the basis of regulation, in particular: cholesterol de novo biosynthesis; uptake of exogenous cholesterol LDL receptor mediated; cholesterol esterification mediated by the ACAT activity; cholesterol efflux HDL receptor mediated. The most recent analytic-spectroscopic applications that permit cholesteryl ester determination on tumor lipidic extracts and directly in vivo are also reported. This review gives an overview of cholesterol homeostasis in physiological and pathological conditions where cholesteryl esters are over-expressed.
Collapse
Affiliation(s)
- Maria R Tosi
- ITOI-CNR, presso IOR, via di Barbiano 1/10, 40136, Bologna, Italy.
| | | |
Collapse
|
9
|
Cao WM, Murao K, Imachi H, Yu X, Dobashi H, Yoshida K, Muraoka T, Kotsuna N, Nagao S, Wong NCW, Ishida T. Insulin-like growth factor-i regulation of hepatic scavenger receptor class BI. Endocrinology 2004; 145:5540-7. [PMID: 15345670 DOI: 10.1210/en.2004-0330] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
High-density lipoprotein mediates a normal physiological process called reverse cholesterol transport. This process enables the transfer of cholesterol from peripheral tissues to the liver for further metabolism and eventual secretion in the form of bile. The scavenger receptor of the B class (SR-BI), human homolog of SR-BI, and CD36 and LIMPII analogous-1 (CLA-1) are different names for the same receptor that facilitates hepatocellular uptake of cholesterol from high-density lipoprotein. The pivotal role of this receptor in enterohepatic circulation of cholesterol and bile salts underlies our interest to study the regulation of hepatic SR-BI gene in response to the actions of IGF-I. The results of our studies showed that endogenous expression of SR-BI/CLA-1 was suppressed by exposure to GH or IGF-I in cultured HepG2 cells. This observation extended to a whole animal model of rats continuously infused with IGF-I. IGF-I decreased transcriptional activity of the SR-BI promoter. However, the inhibitory effect of IGF-I on SR-BI/CLA-1 promoter activity was abrogated by wortmannin, a specific inhibitor of phosphoinositide 3-kinase (PI3-K). Exposure of HepG2 cells to IGF-I elicited a rapid phosphorylation of Akt. We also demonstrated that the constitutively active form of both p110, a subunit of PI3-K, and Akt inhibited activity of the human SR-BI/CLA-1 promoter. Furthermore, the dominant-negative mutant of Akt abolished the ability of IGF-I to suppress activity of the SR-BI/CLA-1 promoter. In conclusion, PI3-K/Akt pathways participate in IGF-I-suppression of SR-BI/CLA-1 expression, which suggests that the activation of Akt plays an important role in cholesterol metabolism in liver.
Collapse
Affiliation(s)
- Wen M Cao
- First Department of Internal Medicine, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Cao WM, Murao K, Imachi H, Yu X, Abe H, Yamauchi A, Niimi M, Miyauchi A, Wong NCW, Ishida T. A mutant high-density lipoprotein receptor inhibits proliferation of human breast cancer cells. Cancer Res 2004; 64:1515-21. [PMID: 14973113 DOI: 10.1158/0008-5472.can-03-0675] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
High-density lipoprotein (HDL) stimulates the growth of many types of cells, including those of breast cancer. High levels of HDL are associated with an increased risk of breast cancer development. A scavenger receptor of the B class (SR-BI)/human homolog of SR-BI, CD36, and LIMPII analogous-1 (CLA-1) facilitates the cellular uptake of cholesterol from HDL and thus augments cell growth. Furthermore, HDL is also believed to have antiapoptotic effects on various cell types, and this feature adds to its ability to promote cell growth. These collaborative roles of HDL and CLA-1 prompted us to assess the function of these components on human breast cancer cells. In this study, we created a mutant CLA-1 (mCLA) that lacked the COOH-terminal tail to determine its potential role in breast cancer cell growth. Expression of mCLA inhibited the proliferation of breast cancer cell line MCF-7. This inhibitory action of mCLA required the transcriptional factor activator protein-1 (AP-1), and the mutant receptor also affected the antiapoptotic features of HDL. The effect of HDL on AP-1 activation and [(3)H]thymidine incorporation was abrogated by wortmannin, a specific inhibitor of phosphoinositide 3-kinase. Furthermore, the dominant negative mutant of Akt abolished the ability of HDL to activate AP-1. These findings raise the possibility that the inhibitors of the effects of HDL may be of therapeutic value for breast cancer.
Collapse
Affiliation(s)
- Wen M Cao
- First Department of Internal Medicine, Kagawa Medical University, 1750-1 Miki-cho, Kita-gun, Kagawa, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|