1
|
Xu R, Yuan W, Wang Z. Advances in Glycolysis Metabolism of Atherosclerosis. J Cardiovasc Transl Res 2022; 16:476-490. [PMID: 36068370 DOI: 10.1007/s12265-022-10311-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 08/29/2022] [Indexed: 11/30/2022]
Abstract
Glycolysis is an important way for various cells such as vascular wall endothelial cells, smooth muscle cells, macrophages, and other cells to obtain energy. In pathological conditions, it can participate in the process of AS by regulating lipid deposition, calcification, angiogenesis in plaques, etc., together with its metabolite lactic acid. Recent studies have shown that lactate-related lactylation modifications are ubiquitous in the human proteome and are involved in the regulation of various inflammatory diseases. Combined with the distribution and metabolic characteristics of cells in the plaque in the process of AS, glycolysis-lactate-lactylation modification may be a new entry point for targeted intervention in atherosclerosis in the future. Therefore, this article intends to elaborate on the role and mechanism of glycolysis-lactate-lactylation modification in AS, as well as the opportunities and challenges in targeted therapy, hoping to bring some help to relevant scholars in this field. In atherosclerosis, glycolysis, lactate, and lactylation modification as a metabolic sequence affect the functions of macrophages, smooth muscle cells, endothelial cells, lymphocytes, and other cells and interfere with processes such as vascular calcification and intraplaque neovascularization to influence the progression of atherosclerosis.
Collapse
Affiliation(s)
- Ruhan Xu
- Department of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, 212001, China
| | - Wei Yuan
- Department of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, 212001, China
| | - Zhongqun Wang
- Department of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, 212001, China.
| |
Collapse
|
2
|
Wang K, Gan C, Wang H, Ao M, Fan Y, Chen Y. AFM detects the effects of acidic condition on the size and biomechanical properties of native/oxidized low-density lipoprotein. Colloids Surf B Biointerfaces 2021; 208:112053. [PMID: 34438294 DOI: 10.1016/j.colsurfb.2021.112053] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 07/06/2021] [Accepted: 08/16/2021] [Indexed: 12/18/2022]
Abstract
Solution acidification exists under some physiological conditions (e.g. lysosomes in cells) and diseases (e.g. atherosclerosis, tumors, etc.). It is poorly understood whether and how acidification influences the size and biomechanical (stiffness and stickiness) properties of native Low-density lipoprotein (LDL) and its oxidized form (oxLDL) which plays a vital role in atherogenesis and tumorigenesis. Atomic force microscopy (AFM) evaluated that gradient acidification from pH 7.4 to pH 4.4 caused an expanding-first-and-then-shrinking decrease in size and a dramatic decrease in stiffness (but no statistically significant changes in stickiness) of LDL/oxLDL particles by influencing secondary/tertiary structures and lipid release detected by infrared spectral analysis and cholesterol detection, respectively. The smaller and softer characteristics of LDL/oxLDL at acidic conditions versus at the neutral pH partially explains the atherogenic role of acidification. The data may provide important information for a better understanding of LDL/oxLDL and some diseases (e.g. atherosclerosis and tumors).
Collapse
Affiliation(s)
- Kun Wang
- Jiangxi Key Laboratory for Microscale interdisciplinary Study, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, 330031, PR China; School of Materials Science and Engineering, Nanchang University, Nanchang, Jiangxi, PR China
| | - Chaoye Gan
- Jiangxi Key Laboratory for Microscale interdisciplinary Study, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, 330031, PR China
| | - Huaying Wang
- Jiangxi Key Laboratory for Microscale interdisciplinary Study, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, 330031, PR China
| | - Meiying Ao
- School of Basic Medical Sciences, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi, 330025, PR China
| | - Youlong Fan
- School of Basic Medical Sciences, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi, 330025, PR China
| | - Yong Chen
- Jiangxi Key Laboratory for Microscale interdisciplinary Study, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, 330031, PR China.
| |
Collapse
|
3
|
Acidic extracellular pH promotes accumulation of free cholesterol in human monocyte-derived macrophages via inhibition of ACAT1 activity. Atherosclerosis 2020; 312:1-7. [PMID: 32942042 DOI: 10.1016/j.atherosclerosis.2020.08.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 08/14/2020] [Accepted: 08/27/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS In focal areas of advanced human atherosclerotic lesions, the intimal fluid is acidic. An acidic medium impairs the ABCA1-mediated cholesterol efflux from macrophages, so tending to increase their content of free cholesterol, which is then available for esterification by the macrophage enzyme ACAT1. Here we investigated whether low extracellular pH would affect the activity of ACAT1. METHODS - Human monocyte-derived macrophages were first incubated with acetyl-LDL at neutral and acidic conditions (pH 7.5, 6.5, and 5.5) to generate foam cells, and then the foam cells were incubated with [3H]oleate-BSA complexes, and the formation of [3H]oleate-labeled cholesteryl esters was measured. ACAT1 activity was also measured in cell-free macrophage extracts. RESULTS - In acidic media, ACAT1-dependent cholesteryl [3H]oleate generation became compromised in the developing foam cells and their content of free cholesterol increased. In line with this finding, ACAT1 activity in the soluble cell-free fraction derived from macrophage foam cells peaked at pH 7, and gradually decreased under acidic pH with a rapid drop below pH 6.5. Incubation of macrophages under progressively more acidic conditions (until pH 5.5) lowered the cytosolic pH of macrophages (down to pH 6.0). Such intracellular acidification did not affect macrophage gene expression of ACAT1 or the neutral CEH. CONCLUSIONS Exposure of human macrophage foam cells to acidic conditions lowers their intracellular pH with simultaneous decrease in ACAT1 activity. This reduces cholesterol esterification and thus leads to accumulation of potentially toxic levels of free cholesterol, a contributing factor to macrophage foam cell death.
Collapse
|
4
|
Zhang RJ, Yin YF, Xie XJ, Gu HF. Acid-sensing ion channels: Linking extracellular acidification with atherosclerosis. Clin Chim Acta 2019; 502:183-190. [PMID: 31901478 DOI: 10.1016/j.cca.2019.12.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 12/30/2019] [Accepted: 12/30/2019] [Indexed: 01/02/2023]
Abstract
Extracellular acidification in atherosclerosis-prone regions of arterial walls is considered pro-atherosclerotic by exerting detrimental effect on macrophages, endothelial cells (ECs) and vascular smooth muscle cells (VSMCs). Acid-sensing ion channels (ASICs), a family of extracellular H+ (proton)-gated cation channels, are present extensively in the nervous system and other tissues, implying physiologic as well as pathophysiologic importance. Aberrant activation of ASICs is thought to be associated in EC dysfunction, macrophage phenotypic switch, and VSMC migration and proliferation. Although in vitro evidence acknowledges the contribution of ASIC activation in atherosclerosis, no direct evidence confirms their pro-atherosclerotic roles in vivo. In this review, the effect of extracellular acidity on three major contributors, ECs, macrophages, and VSMCs, is discussed focusing on the potential roles of ASICs in atherosclerotic development and underlying pathology. A more comprehensive understanding of ASICs in these processes may provide promising new therapeutic targets for treatment and prevention of atherosclerotic diseases.
Collapse
Affiliation(s)
- Rong-Jie Zhang
- Department of Physiology & Institute of Neuroscience, University of South China, Hengyang, People's Republic of China
| | - Yu-Fang Yin
- Department of Neuroscience and Pharmacology, School of Medicine, Southern Illinois University Springfield, Illinois, United States
| | - Xue-Jiao Xie
- Department of Zhongjing' Theory, College of Chinese Medicine, Hunan University of Chinese Medicine, Changsha, People's Republic of China.
| | - Hong-Feng Gu
- Department of Physiology & Institute of Neuroscience, University of South China, Hengyang, People's Republic of China.
| |
Collapse
|
5
|
Bång-Rudenstam A, Cerezo-Magaña M, Belting M. Pro-metastatic functions of lipoproteins and extracellular vesicles in the acidic tumor microenvironment. Cancer Metastasis Rev 2019; 38:79-92. [PMID: 30767150 PMCID: PMC6647379 DOI: 10.1007/s10555-019-09786-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Although the overall mortality in cancer is steadily decreasing, major groups of patients still respond poorly to available treatments. The key clinical challenge discussed here relates to the inherent capacity of cancer cells to metabolically adapt to hypoxic and acidic stress, resulting in treatment resistance and a pro-metastatic behavior. Hence, a detailed understanding of stress adaptive responses is critical for the design of more rational therapeutic strategies for cancer. We will focus on the emerging role of extracellular vesicles (EVs) and lipoprotein particles in cancer cell metabolic stress adaptation and how these pathways may constitute potential Achilles' heels of the cancer cell machinery and alternative treatment targets of metastasis. In this context, common extracellular lipid uptake mechanisms, involving specific cell-surface receptors and endocytic pathways, may operate during remodeling of acidic atherosclerotic plaques as well as the tumor microenvironment. The role of endocytosis in regulating the cellular response to hypoxic and acidic stress through spatial coordination of receptor proteins may be exploited for therapeutic purposes. As a consequence, molecular mechanisms of endocytosis have attracted increasing attention as potential targets for tumor specific delivery of therapeutic substances, such as antibody-drug conjugates. The identification of internalizing surface proteins specific to the acidic tumor niche remains an unmet need of high clinical relevance. Among the currently explored, acidosis-related, internalizing target proteins, we will focus on the cell-surface proteoglycan carbonic anhydrase 9.
Collapse
Affiliation(s)
- Anna Bång-Rudenstam
- Department of Clinical Sciences Lund, Section of Oncology and Pathology, Lund University, Barngatan 4, SE-221 85, Lund, Sweden
| | - Myriam Cerezo-Magaña
- Department of Clinical Sciences Lund, Section of Oncology and Pathology, Lund University, Barngatan 4, SE-221 85, Lund, Sweden
| | - Mattias Belting
- Department of Clinical Sciences Lund, Section of Oncology and Pathology, Lund University, Barngatan 4, SE-221 85, Lund, Sweden.
| |
Collapse
|
6
|
Menard JA, Christianson HC, Kucharzewska P, Bourseau-Guilmain E, Svensson KJ, Lindqvist E, Indira Chandran V, Kjellén L, Welinder C, Bengzon J, Johansson MC, Belting M. Metastasis Stimulation by Hypoxia and Acidosis-Induced Extracellular Lipid Uptake Is Mediated by Proteoglycan-Dependent Endocytosis. Cancer Res 2016; 76:4828-40. [PMID: 27199348 DOI: 10.1158/0008-5472.can-15-2831] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Accepted: 05/05/2016] [Indexed: 01/03/2023]
Abstract
Hypoxia and acidosis are inherent stress factors of the tumor microenvironment and have been linked to increased tumor aggressiveness and treatment resistance. Molecules involved in the adaptive mechanisms that drive stress-induced disease progression constitute interesting candidates of therapeutic intervention. Here, we provide evidence of a novel role of heparan sulfate proteoglycans (HSPG) in the adaptive response of tumor cells to hypoxia and acidosis through increased internalization of lipoproteins, resulting in a lipid-storing phenotype and enhanced tumor-forming capacity. Patient glioblastoma tumors and cells under hypoxic and acidic stress acquired a lipid droplet (LD)-loaded phenotype, and showed an increased recruitment of all major lipoproteins, HDL, LDL, and VLDL. Stress-induced LD accumulation was associated with increased spheroid-forming capacity during reoxygenation in vitro and lung metastatic potential in vivo On a mechanistic level, we found no apparent effect of hypoxia on HSPGs, whereas lipoprotein receptors (VLDLR and SR-B1) were transiently upregulated by hypoxia. Importantly, however, using pharmacologic and genetic approaches, we show that stress-mediated lipoprotein uptake is highly dependent on intact HSPG expression. The functional relevance of HSPG in the context of tumor cell stress was evidenced by HSPG-dependent lipoprotein cell signaling activation through the ERK/MAPK pathway and by reversal of the LD-loaded phenotype by targeting of HSPGs. We conclude that HSPGs may have an important role in the adaptive response to major stress factors of the tumor microenvironment, with functional consequences on tumor cell signaling and metastatic potential. Cancer Res; 76(16); 4828-40. ©2016 AACR.
Collapse
Affiliation(s)
- Julien A Menard
- Department of Clinical Sciences, Section of Oncology and Pathology, Lund University, Lund, Sweden
| | - Helena C Christianson
- Department of Clinical Sciences, Section of Oncology and Pathology, Lund University, Lund, Sweden
| | - Paulina Kucharzewska
- Department of Clinical Sciences, Section of Oncology and Pathology, Lund University, Lund, Sweden
| | - Erika Bourseau-Guilmain
- Department of Clinical Sciences, Section of Oncology and Pathology, Lund University, Lund, Sweden
| | - Katrin J Svensson
- Dana-Farber Cancer Institute and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| | - Eva Lindqvist
- Department of Clinical Sciences, Section of Oncology and Pathology, Lund University, Lund, Sweden
| | - Vineesh Indira Chandran
- Department of Clinical Sciences, Section of Oncology and Pathology, Lund University, Lund, Sweden
| | - Lena Kjellén
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Charlotte Welinder
- Department of Clinical Sciences, Section of Oncology and Pathology, Lund University, Lund, Sweden. Center of Excellence in Biological and Medical Mass Spectrometry "CEBMMS", Biomedical Centre D13, Lund University, Lund, Sweden
| | - Johan Bengzon
- Lund Stem Cell Center, Lund University, Lund, Sweden. Department of Clinical Sciences, Section of Neurosurgery, Lund University, Lund, Sweden
| | - Maria C Johansson
- Department of Clinical Sciences, Section of Oncology and Pathology, Lund University, Lund, Sweden
| | - Mattias Belting
- Department of Clinical Sciences, Section of Oncology and Pathology, Lund University, Lund, Sweden. Skåne University Hospital, Lund, Sweden.
| |
Collapse
|
7
|
Öörni K, Rajamäki K, Nguyen SD, Lähdesmäki K, Plihtari R, Lee-Rueckert M, Kovanen PT. Acidification of the intimal fluid: the perfect storm for atherogenesis. J Lipid Res 2014; 56:203-14. [PMID: 25424004 DOI: 10.1194/jlr.r050252] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Atherosclerotic lesions are often hypoxic and exhibit elevated lactate concentrations and local acidification of the extracellular fluids. The acidification may be a consequence of the abundant accumulation of lipid-scavenging macrophages in the lesions. Activated macrophages have a very high energy demand and they preferentially use glycolysis for ATP synthesis even under normoxic conditions, resulting in enhanced local generation and secretion of lactate and protons. In this review, we summarize our current understanding of the effects of acidic extracellular pH on three key players in atherogenesis: macrophages, apoB-containing lipoproteins, and HDL particles. Acidic extracellular pH enhances receptor-mediated phagocytosis and antigen presentation by macrophages and, importantly, triggers the secretion of proinflammatory cytokines from macrophages through activation of the inflammasome pathway. Acidity enhances the proteolytic, lipolytic, and oxidative modifications of LDL and other apoB-containing lipoproteins, and strongly increases their affinity for proteoglycans, and may thus have major effects on their retention and the ensuing cellular responses in the arterial intima. Finally, the decrease in the expression of ABCA1 at acidic pH may compromise cholesterol clearance from atherosclerotic lesions. Taken together, acidic extracellular pH amplifies the proatherogenic and proinflammatory processes involved in atherogenesis.
Collapse
|
8
|
Lu M, Kho T, Munford RS. Prolonged triglyceride storage in macrophages: pHo trumps pO2 and TLR4. THE JOURNAL OF IMMUNOLOGY 2014; 193:1392-7. [PMID: 24973452 DOI: 10.4049/jimmunol.1400886] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Lipid-laden macrophages contribute to pathologies as diverse as atherosclerosis and tuberculosis. Three common stimuli are known to promote macrophage lipid storage: low tissue oxygen tension (pO2), low extracellular pH (pHo), and exposure to agonists such as bacterial LPS. Noting that cells responding to low pO2 or agonistic bacterial molecules often decrease pHo by secreting lactic and other carboxylic acids, we studied how pHo influences the stimulation of triacylglycerol (TAG) storage by low pO2 and LPS. We found that TAG retention after incubation for 48-72 h was inversely related to pHo when primary macrophages were cultured in 21% oxygen, 4% oxygen, or with LPS at either oxygen concentration. Maintaining pHo at ~7.4 was sufficient to prevent the increase in prolonged TAG storage induced by either low pO2 or LPS. The strong influence of pHo on TAG retention may explain why lipid-laden macrophages are found in some tissue environments and not in others. It is also possible that other long-term cellular changes currently attributed to low pO2 or bacterial agonists may be promoted, at least in part, by the decrease in pHo that these stimuli induce.
Collapse
Affiliation(s)
- Mingfang Lu
- Antibacterial Host Defense Unit, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Terry Kho
- Antibacterial Host Defense Unit, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Robert S Munford
- Antibacterial Host Defense Unit, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| |
Collapse
|
9
|
CHI LIYI, PENG LIJING, HU XIAOJING, PAN NA, ZHANG YANHAI. Berberine combined with atorvastatin downregulates LOX-1 expression through the ET-1 receptor in monocyte/macrophages. Int J Mol Med 2014; 34:283-90. [DOI: 10.3892/ijmm.2014.1748] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 03/18/2014] [Indexed: 11/05/2022] Open
|
10
|
Camejo G, Hurt-Camejo E. Macrophages, extracellular matrix, and lipoproteins in arterial cholesterol balance. J Lipid Res 2013; 55:1-3. [PMID: 24253373 DOI: 10.1194/jlr.e045732] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Germán Camejo
- Cardiovascular and Metabolic Diseases, AstraZeneca, Mölndal, 431 83, Sweden
| | | |
Collapse
|
11
|
Umaerus M, Rosengren B, Fagerberg B, Hurt-Camejo E, Camejo G. HDL2 interferes with LDL association with arterial proteoglycans: A possible athero-protective effect. Atherosclerosis 2012; 225:115-20. [DOI: 10.1016/j.atherosclerosis.2012.08.040] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 08/06/2012] [Accepted: 08/31/2012] [Indexed: 02/06/2023]
|
12
|
|
13
|
Melnichenko AA, Aksenov DV, Myasoedova VA, Panasenko OM, Yaroslavov AA, Sobenin IA, Bobryshev YV, Orekhov AN. Pluronic block copolymers inhibit low density lipoprotein self-association. Lipids 2012; 47:995-1000. [PMID: 22797973 DOI: 10.1007/s11745-012-3699-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 06/28/2012] [Indexed: 01/30/2023]
Abstract
Little is known about exogenous inhibitors of low-density lipoprotein (LDL) aggregation. The search for nontoxic and bioavailable inhibitors of LDL aggregation is of interest, especially considering that the suppression of the aggregation of LDL might represent a therapeutic approach. We hypothesized that amphiphilic copolymers of propylene oxide and ethylene oxide, the so-called Pluronic block copolymers, can be used to influence the aggregation of LDL. In this work we used Pluronic® P85, L61 and F68. A comparative study of the effects of Pluronic block copolymers with various hydrophilic-lipophilic properties on the aggregation process of LDL showed that Pluronic copolymers with strong hydrophobic properties (P85 and L61) at concentrations close to or greater than the respective critical concentration of micelle formation inhibited the aggregation process of LDL; however, the "hydrophilic" Pluronic F68 had no effect on the aggregation of LDL at any concentration. Thus, the study demonstrated for the first time that Pluronic® block copolymers inhibit LDL self-association. The possibility of modulating the aggregation of LDL by various Pluronic copolymers can be regarded as a prerequisite in the creation of new types of anti-atherosclerotic drugs.
Collapse
Affiliation(s)
- Alexandra A Melnichenko
- Institute of General Pathology and Pathophysiology, Russian Academy of Medical Sciences, Moscow, Russia
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Lähdesmäki K, Öörni K, Alanne-Kinnunen M, Jauhiainen M, Hurt-Camejo E, Kovanen PT. Acidity and lipolysis by group V secreted phospholipase A2 strongly increase the binding of apoB-100-containing lipoproteins to human aortic proteoglycans. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:257-67. [DOI: 10.1016/j.bbalip.2011.10.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 10/11/2011] [Accepted: 10/17/2011] [Indexed: 11/16/2022]
|