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Yang RM, Zou Y, Huang DP, Lai SS, Xu XD, Wei XH, Chang HZ, Huang TK, Wang L, Tang WJ, Jiang XQ. In vivo assessment of the vascular disrupting effect of M410 by DCE-MRI biomarker in a rabbit model of liver tumor. Oncol Rep 2014; 32:709-15. [PMID: 24898785 DOI: 10.3892/or.2014.3230] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 04/07/2014] [Indexed: 11/05/2022] Open
Abstract
The present study aimed to prospectively monitor the vascular disrupting effect of M410 by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in rabbits with VX2 liver tumors. Twenty-eight rabbits bearing VX2 tumors in the left lobe of the liver were established and randomly divided into treatment and control groups, intravenously injected with 25 mg/kg M410 or sterile saline, respectively. Conventional and DCE-MRI data were acquired on a 3.0-T MR unit at pretreatment, 4 h, 1, 4, 7 and 14 days post-treatment. Histopathological examinations [hematoxylin and eosin (H&E) and CD34 immunohistochemisty staining] were performed at each time point. The dynamic changes in tumor volume, kinetic DCE-MRI parameter [volume transfer constant (Ktrans)] and histological data were evaluated. Tumors grew slower in the M410 group 4-14 days following treatment, compared with rapidly growing tumors in the control group (P<0.05). At 4 h, 1 and 4 days, Ktrans significantly decreased in the M410 group compared with that in the control group (P<0.05). However, Ktrans values were similar in the two groups for the other time points studied. The changes in DCE-MRI parameters were consistent with the results obtained from H&E and CD34 staining of the tumor tissues. DCE-MRI parameter Ktrans may be used as a non-invasive imaging biomarker to monitor the dynamic histological changes in tumors following treatment with the vascular targeting agent M410.
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Affiliation(s)
- Rui-Meng Yang
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
| | - Yong Zou
- Guangzhou Institute of Chemistry, Chinese Academy of Science, Guangzhou 510650, P.R. China
| | - Dan-Ping Huang
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
| | - Sheng-Sheng Lai
- Department of Medical Equipment, Guangdong Food and Drug Vocational College, Guangzhou 510520, P.R. China
| | - Xiang-Dong Xu
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
| | - Xin-Hua Wei
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
| | - Han-Zheng Chang
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
| | - Tong-Kun Huang
- Guangzhou Institute of Chemistry, Chinese Academy of Science, Guangzhou 510650, P.R. China
| | - Li Wang
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
| | - Wen-Jie Tang
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
| | - Xin-Qing Jiang
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
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Cholesterol in the retina: the best is yet to come. Prog Retin Eye Res 2014; 41:64-89. [PMID: 24704580 DOI: 10.1016/j.preteyeres.2014.03.002] [Citation(s) in RCA: 191] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 03/13/2014] [Accepted: 03/17/2014] [Indexed: 01/09/2023]
Abstract
Historically understudied, cholesterol in the retina is receiving more attention now because of genetic studies showing that several cholesterol-related genes are risk factors for age-related macular degeneration (AMD) and because of eye pathology studies showing high cholesterol content of drusen, aging Bruch's membrane, and newly found subretinal lesions. The challenge before us is determining how the cholesterol-AMD link is realized. Meeting this challenge will require an excellent understanding these genes' roles in retinal physiology and how chorioretinal cholesterol is maintained. In the first half of this review, we will succinctly summarize physico-chemical properties of cholesterol, its distribution in the human body, general principles of maintenance and metabolism, and differences in cholesterol handling in human and mouse that impact on experimental approaches. This information will provide a backdrop to the second part of the review focusing on unique aspects of chorioretinal cholesterol homeostasis, aging in Bruch's membrane, cholesterol in AMD lesions, a model for lesion biogenesis, a model for macular vulnerability based on vascular biology, and alignment of AMD-related genes and pathobiology using cholesterol and an atherosclerosis-like progression as unifying features. We conclude with recommendations for the most important research steps we can take towards delineating the cholesterol-AMD link.
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AFM of the Ultrastructural and Mechanical Properties of Lipid-Raft-Disrupted and/or Cold-Treated Endothelial Cells. J Membr Biol 2014; 247:189-200. [DOI: 10.1007/s00232-013-9624-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 12/26/2013] [Indexed: 01/08/2023]
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De Boussac H, Alioui A, Viennois E, Dufour J, Trousson A, Vega A, Guy L, Volle DH, Lobaccaro JMA, Baron S. Oxysterol receptors and their therapeutic applications in cancer conditions. Expert Opin Ther Targets 2013; 17:1029-38. [PMID: 23875732 DOI: 10.1517/14728222.2013.820708] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Oxysterols are implicated in various cellular processes. Among their target proteins, liver X receptors (LXRs) α and β modulate the cell cycle in a large range of cancer cell lines. Besides their role as cholesterol sensors, LXRs are also involved in the proliferation/apoptosis balance regulation in various types of cancers. AREAS COVERED This review covers oxysterols and derivatives of cholesterol as well as synthetic or natural ligands (agonist/antagonist) of LXRs. Most tumor cell lines are sensitive to LXR activation. Indeed various cancers are concerned such as prostate, breast, glioblastoma, colorectal, and ovary tumors, and leukemia. EXPERT OPINION Developing the use of LXR ligands in human health, especially in the field of cancer, represents a novel and promising strategy. Despite a wide spectrum of applications, numerous adverse effects of LXR activation need to be solved before genuine clinical trials in humans. Future directions will be based on the engineering of selective LXRs modulators (SLiMs) as already done for nuclear steroid receptors.
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Affiliation(s)
- Hugues De Boussac
- Clermont Université, Université Blaise Pascal, Génétique Reproduction et Développement, BP 10448, F-63000 Clermont-Ferrand, France
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Cubbon RM, Mercer BN, Sengupta A, Kearney MT. Importance of insulin resistance to vascular repair and regeneration. Free Radic Biol Med 2013; 60:246-63. [PMID: 23466555 DOI: 10.1016/j.freeradbiomed.2013.02.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 02/22/2013] [Accepted: 02/23/2013] [Indexed: 01/14/2023]
Abstract
Metabolic insulin resistance is apparent across a spectrum of clinical disorders, including obesity and diabetes, and is characterized by an adverse clustering of cardiovascular risk factors related to abnormal cellular responses to insulin. These disorders are becoming increasingly prevalent and represent a major global public health concern because of their association with significant increases in atherosclerosis-related mortality. Endogenous repair mechanisms are thought to retard the development of vascular disease, and a growing evidence base supports the adverse impact of the insulin-resistant phenotype upon indices of vascular repair. Beyond the impact of systemic metabolic changes, emerging data from murine studies also provide support for abnormal insulin signaling at the level of vascular cells in retarding vascular repair. Interrelated pathophysiological factors, including reduced nitric oxide bioavailability, oxidative stress, altered growth factor activity, and abnormal intracellular signaling, are likely to act in conjunction to impede vascular repair while also driving vascular damage. Understanding of these processes is shaping novel therapeutic paradigms that aim to promote vascular repair and regeneration, either by recruiting endogenous mechanisms or by the administration of cell-based therapies.
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Affiliation(s)
- Richard M Cubbon
- Multidisciplinary Cardiovascular Research Centre, LIGHT Laboratories, The University of Leeds, Leeds LS2 9JT, UK.
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Fang L, Choi SH, Baek JS, Liu C, Almazan F, Ulrich F, Wiesner P, Taleb A, Deer E, Pattison J, Torres-Vázquez J, Li AC, Miller YI. Control of angiogenesis by AIBP-mediated cholesterol efflux. Nature 2013; 498:118-22. [PMID: 23719382 PMCID: PMC3760669 DOI: 10.1038/nature12166] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 04/08/2013] [Indexed: 12/26/2022]
Abstract
Cholesterol is a structural component of the cell, indispensable for normal cellular function, but its excess often leads to abnormal proliferation, migration, inflammatory responses and/or cell death. To prevent cholesterol overload, ATP-binding cassette (ABC) transporters mediate cholesterol efflux from the cells to apolipoprotein A-I (ApoA-I) and to the ApoA-I-containing high-density lipoprotein (HDL)1-3. Maintaining efficient cholesterol efflux is essential for normal cellular function4-6. However, the role of cholesterol efflux in angiogenesis and the identity of its local regulators are poorly understood. Here we show that ApoA-I binding protein (AIBP) accelerates cholesterol efflux from endothelial cells (EC) to HDL and thereby regulates angiogenesis. AIBP/HDL-mediated cholesterol depletion reduces lipid rafts, interferes with VEGFR2 dimerization and signaling, and inhibits VEGF-induced angiogenesis in vitro and mouse aortic neovascularization ex vivo. Remarkably, Aibp regulates the membrane lipid order in embryonic zebrafish vasculature and functions as a non-cell autonomous regulator of zebrafish angiogenesis. Aibp knockdown results in dysregulated sprouting/branching angiogenesis, while forced Aibp expression inhibits angiogenesis. Dysregulated angiogenesis is phenocopied in Abca1/Abcg1-deficient embryos, and cholesterol levels are increased in Aibp-deficient and Abca1/Abcg1-deficient embryos. Our findings demonstrate that secreted AIBP positively regulates cholesterol efflux from EC and that effective cholesterol efflux is critical for proper angiogenesis.
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Affiliation(s)
- Longhou Fang
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
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