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Tan X, Yan K, Ren M, Chen N, Li Y, Deng X, Wang L, Li R, Luo M, Liu Y, Liu Y, Wu J. Angiopoietin-2 impairs collateral artery growth associated with the suppression of the infiltration of macrophages in mouse hindlimb ischaemia. J Transl Med 2016; 14:306. [PMID: 27784306 PMCID: PMC5080762 DOI: 10.1186/s12967-016-1055-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 10/10/2016] [Indexed: 12/01/2022] Open
Abstract
Background Angiopoietin-2 (Ang-2), a ligand of the Tie-2 receptor, plays an important role in maintaining endothelial cells and in destabilizing blood vessels. Collateral artery growth (arteriogenesis) is a key adaptive response to arterial occlusion. It is unknown whether the destabilization of blood vessels by Ang-2 can affect arteriogenesis and modulate mononuclear cell function. This study aimed to investigate the effects of Ang-2 on collateral artery growth. Methods Hindlimb ischaemia model was produced in C57BL/6 mice by femoral artery ligation. Blood flow perfusion was measured using a laser Doppler perfusion imager quantitative RT-PCR analysis was applied to identify the level of angiogenic factors. Results After the induction of hindlimb ischaemia, blood flow recovery was impaired in mice treated with recombinant Ang-2 protein; this was accompanied by a reduction of peri-collateral macrophage infiltration. In addition, quantitative RT-PCR analysis revealed that Ang-2 treatment decreased monocyte chemotactic protein-1 (MCP-1), platelet-derived growth factor-BB (PDGF-BB) mRNA levels in ischaemic adductor muscles. Ang-2 can lead to macrophage M1/M2 polarization shift inhibition in the ischaemic muscles. Furthermore, Ang-2 reduced the in vitro inflammatory response in macrophages and vascular cells involved in arteriogenesis. Conclusions Our results demonstrate that Ang-2 is essential for efficient arteriogenesis, which controls macrophage infiltration. Electronic supplementary material The online version of this article (doi:10.1186/s12967-016-1055-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiaoyong Tan
- Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China.,Laboratory for Cardiovascular Pharmacology of Department of Pharmacology, The School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Kai Yan
- Renshou People's Hospital, Renshou, Sichuan, China
| | - Meiping Ren
- Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China.,Laboratory for Cardiovascular Pharmacology of Department of Pharmacology, The School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Ni Chen
- Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China.,Laboratory for Cardiovascular Pharmacology of Department of Pharmacology, The School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Yongjie Li
- Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China.,Laboratory for Cardiovascular Pharmacology of Department of Pharmacology, The School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Xin Deng
- Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China.,Laboratory for Cardiovascular Pharmacology of Department of Pharmacology, The School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Liqun Wang
- Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China.,Laboratory for Cardiovascular Pharmacology of Department of Pharmacology, The School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Rong Li
- Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China.,Laboratory for Cardiovascular Pharmacology of Department of Pharmacology, The School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Mao Luo
- Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China.,Laboratory for Cardiovascular Pharmacology of Department of Pharmacology, The School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Yong Liu
- Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China.,Laboratory for Cardiovascular Pharmacology of Department of Pharmacology, The School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Yan Liu
- Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China.,Laboratory for Cardiovascular Pharmacology of Department of Pharmacology, The School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Jianbo Wu
- Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China. .,Laboratory for Cardiovascular Pharmacology of Department of Pharmacology, The School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China. .,Department of Internal Medicine, University of Missouri School of Medicine, Columbia, MO, USA.
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102
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Yadranji Aghdam S, Mahmoudpour A. Proteasome Activators, PA28 α and PA28 β, Govern Development of Microvascular Injury in Diabetic Nephropathy and Retinopathy. Int J Nephrol 2016; 2016:3846573. [PMID: 27830089 PMCID: PMC5088333 DOI: 10.1155/2016/3846573] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 08/08/2016] [Accepted: 09/06/2016] [Indexed: 12/25/2022] Open
Abstract
Diabetic nephropathy (DN) and diabetic retinopathy (DR) are major complications of type 1 and type 2 diabetes. DN and DR are mainly caused by injury to the perivascular supporting cells, the mesangial cells within the glomerulus, and the pericytes in the retina. The genes and molecular mechanisms predisposing retinal and glomerular pericytes to diabetic injury are poorly characterized. In this study, the genetic deletion of proteasome activator genes, PA28α and PA28β genes, protected the diabetic mice in the experimental STZ-induced diabetes model against renal injury and retinal microvascular injury and prolonged their survival compared with wild type STZ diabetic mice. The improved wellbeing and reduced renal damage was associated with diminished expression of Osteopontin (OPN) and Monocyte Chemoattractant Protein-1 (MCP-1) in the glomeruli of STZ-injected PA28α/PA28β double knockout (Pa28αβDKO) mice and also in cultured mesangial cells and retinal pericytes isolated from Pa28αβDKO mice that were grown in high glucose. The mesangial PA28-mediated expression of OPN under high glucose conditions was suppressed by peptides capable of inhibiting the binding of PA28 to the 20S proteasome. Collectively, our findings demonstrate that diabetic hyperglycemia promotes PA28-mediated alteration of proteasome activity in vulnerable perivascular cells resulting in microvascular injury and development of DN and DR.
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Affiliation(s)
- Saeed Yadranji Aghdam
- Reynolds Institute on Aging, Room No. 4151, 629 Jack Stephens Drive, Little Rock, AR 72205, USA
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Ali Mahmoudpour
- Norgen Biotek Corp., 3430 Schmon Parkway, Thorold, ON, Canada L2V 4Y6
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103
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Gupta A, Bhatnagar S. Vasoregression: A Shared Vascular Pathology Underlying Macrovascular And Microvascular Pathologies? OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2016; 19:733-53. [PMID: 26669709 DOI: 10.1089/omi.2015.0128] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Vasoregression is a common phenomenon underlying physiological vessel development as well as pathological microvascular diseases leading to peripheral neuropathy, nephropathy, and vascular oculopathies. In this review, we describe the hallmarks and pathways of vasoregression. We argue here that there is a parallel between characteristic features of vasoregression in the ocular microvessels and atherosclerosis in the larger vessels. Shared molecular pathways and molecular effectors in the two conditions are outlined, thus highlighting the possible systemic causes of local vascular diseases. Our review gives us a system-wide insight into factors leading to multiple synchronous vascular diseases. Because shared molecular pathways might usefully address the diagnostic and therapeutic needs of multiple common complex diseases, the literature analysis presented here is of broad interest to readership in integrative biology, rational drug development and systems medicine.
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Affiliation(s)
- Akanksha Gupta
- 1 Computational and Structural Biology Laboratory, Division of Biotechnology, Netaji Subhas Institute of Technology , Dwarka, New Delhi, India .,2 Department of Biotechnology, IMS Engineering College , Ghaziabad, India
| | - Sonika Bhatnagar
- 1 Computational and Structural Biology Laboratory, Division of Biotechnology, Netaji Subhas Institute of Technology , Dwarka, New Delhi, India
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104
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Caporali A, Martello A, Miscianinov V, Maselli D, Vono R, Spinetti G. Contribution of pericyte paracrine regulation of the endothelium to angiogenesis. Pharmacol Ther 2016; 171:56-64. [PMID: 27742570 DOI: 10.1016/j.pharmthera.2016.10.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
During physiological development and after a stressor event, vascular cells communicate with each other to evoke new vessel formation-a process known as angiogenesis. This communication occurs via direct contact and via paracrine release of proteins and nucleic acids, both in a free form or encapsulated into micro-vesicles. In diseases with an altered angiogenic response, such as cancer and diabetic vascular complications, it becomes of paramount importance to tune the cell communication process. Endothelial cell growth and migration are essential processes for new vessel formation, and pericytes, together with some classes of circulating monocytes, are important endothelial regulators. The interaction between pericytes and the endothelium is facilitated by their anatomical apposition, which involves endothelial cells and pericytes sharing the same basement membrane. However, the role of pericytes is not fully understood. The characteristics and the function of tissue-specific pericytesis are the focus of this review. Factors involved in the cross-talk between these cell types and the opportunities afforded by micro-RNA and micro-vesicle techniques are discussed. Targeting these mechanisms in pathological conditions, in which the vessel response is altered, is considered in relation to identification of new therapies for restoring the blood flow.
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Affiliation(s)
- A Caporali
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - A Martello
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - V Miscianinov
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - D Maselli
- IRCCS MultiMedica, Milan, Italy; Dipartimento di Scienze Biomediche, Università di Sassari, Sassari, Italy
| | - R Vono
- IRCCS MultiMedica, Milan, Italy
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105
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Kim M, Allen B, Korhonen EA, Nitschké M, Yang HW, Baluk P, Saharinen P, Alitalo K, Daly C, Thurston G, McDonald DM. Opposing actions of angiopoietin-2 on Tie2 signaling and FOXO1 activation. J Clin Invest 2016; 126:3511-25. [PMID: 27548529 DOI: 10.1172/jci84871] [Citation(s) in RCA: 153] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 06/24/2016] [Indexed: 01/12/2023] Open
Abstract
Angiopoietin-2 (ANG2) regulates blood vessel remodeling in many pathological conditions through differential effects on Tie2 signaling. While ANG2 competes with ANG1 to inhibit Tie2, it can paradoxically also promote Tie2 phosphorylation (p-Tie2). A related paradox is that both inactivation and overactivation of Tie2 can result in vascular remodeling. Here, we reconciled these opposing actions of ANG2 by manipulating conditions that govern its actions in the vasculature. ANG2 drove vascular remodeling during Mycoplasma pulmonis infection by acting as a Tie2 antagonist, which led to p-Tie2 suppression, forkhead box O1 (FOXO1) activation, increased ANG2 expression, and vessel leakiness. These changes were exaggerated by anti-Tie2 antibody, inhibition of PI3K signaling, or ANG2 overexpression and were reduced by anti-ANG2 antibody or exogenous ANG1. In contrast, under pathogen-free conditions, ANG2 drove vascular remodeling by acting as an agonist, promoting high p-Tie2, low FOXO1 activation, and no leakage. Tie1 activation was strong under pathogen-free conditions, but infection or TNF-α led to Tie1 inactivation by ectodomain cleavage and promoted the Tie2 antagonist action of ANG2. Together, these data indicate that ANG2 activation of Tie2 supports stable enlargement of normal nonleaky vessels, but reduction of Tie1 in inflammation leads to ANG2 antagonism of Tie2 and initiates a positive feedback loop wherein FOXO1-driven ANG2 expression promotes vascular remodeling and leakage.
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106
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Korhonen EA, Lampinen A, Giri H, Anisimov A, Kim M, Allen B, Fang S, D'Amico G, Sipilä TJ, Lohela M, Strandin T, Vaheri A, Ylä-Herttuala S, Koh GY, McDonald DM, Alitalo K, Saharinen P. Tie1 controls angiopoietin function in vascular remodeling and inflammation. J Clin Invest 2016; 126:3495-510. [PMID: 27548530 DOI: 10.1172/jci84923] [Citation(s) in RCA: 169] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 06/24/2016] [Indexed: 12/11/2022] Open
Abstract
The angiopoietin/Tie (ANG/Tie) receptor system controls developmental and tumor angiogenesis, inflammatory vascular remodeling, and vessel leakage. ANG1 is a Tie2 agonist that promotes vascular stabilization in inflammation and sepsis, whereas ANG2 is a context-dependent Tie2 agonist or antagonist. A limited understanding of ANG signaling mechanisms and the orphan receptor Tie1 has hindered development of ANG/Tie-targeted therapeutics. Here, we determined that both ANG1 and ANG2 binding to Tie2 increases Tie1-Tie2 interactions in a β1 integrin-dependent manner and that Tie1 regulates ANG-induced Tie2 trafficking in endothelial cells. Endothelial Tie1 was essential for the agonist activity of ANG1 and autocrine ANG2. Deletion of endothelial Tie1 in mice reduced Tie2 phosphorylation and downstream Akt activation, increased FOXO1 nuclear localization and transcriptional activation, and prevented ANG1- and ANG2-induced capillary-to-venous remodeling. However, in acute endotoxemia, the Tie1 ectodomain that is responsible for interaction with Tie2 was rapidly cleaved, ANG1 agonist activity was decreased, and autocrine ANG2 agonist activity was lost, which led to suppression of Tie2 signaling. Tie1 cleavage also occurred in patients with hantavirus infection. These results support a model in which Tie1 directly interacts with Tie2 to promote ANG-induced vascular responses under noninflammatory conditions, whereas in inflammation, Tie1 cleavage contributes to loss of ANG2 agonist activity and vascular stability.
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107
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Trivedi A, Zhang H, Ekeledo A, Lee S, Werb Z, Plant GW, Noble-Haeusslein LJ. Deficiency in matrix metalloproteinase-2 results in long-term vascular instability and regression in the injured mouse spinal cord. Exp Neurol 2016; 284:50-62. [PMID: 27468657 DOI: 10.1016/j.expneurol.2016.07.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 07/13/2016] [Accepted: 07/24/2016] [Indexed: 10/21/2022]
Abstract
Angiogenesis plays a critical role in wound healing after spinal cord injury. Therefore, understanding the events that regulate angiogenesis has considerable relevance from a therapeutic standpoint. We evaluated the contribution of matrix metalloproteinase (MMP)-2 to angiogenesis and vascular stability in spinal cord injured MMP-2 knockout and wildtype (WT) littermates. While MMP-2 deficiency resulted in reduced endothelial cell division within the lesioned epicenter, there were no genotypic differences in vascularity (vascular density, vascular area, and endothelial cell number) over the first two weeks post-injury. However, by 21days post-injury MMP-2 deficiency resulted in a sharp decline in vascularity, indicative of vascular regression. Complementary in vitro studies of brain capillary endothelial cells confirmed MMP-2 dependent proliferation and tube formation. As deficiency in MMP-2 led to prolonged MMP-9 expression in the injured spinal cord, we examined both short-term and long-term exposure to MMP-9 in vitro. While MMP-9 supported endothelial tube formation and proliferation, prolonged exposure resulted in loss of tubes, findings consistent with vascular regression. Vascular instability is frequently associated with pericyte dissociation and precedes vascular regression. Quantification of PDGFrβ+ pericyte coverage of mature vessels within the glial scar (the reactive gliosis zone), a known source of MMP-9, revealed reduced coverage in MMP-2 deficient animals. These findings suggest that acting in the absence of MMP-2, MMP-9 transiently supports angiogenesis during the early phase of wound healing while its prolonged expression leads to vascular instability and regression. These findings should be considered while developing therapeutic interventions that block MMPs.
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Affiliation(s)
- Alpa Trivedi
- Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA.
| | - Haoqian Zhang
- Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA
| | - Adanma Ekeledo
- Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA
| | - Sangmi Lee
- Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA
| | - Zena Werb
- Department of Anatomy, University of California, San Francisco, CA 94143, USA
| | - Giles W Plant
- Department of Neurosurgery, Stanford University, Stanford, CA 94305-5454, USA
| | - Linda J Noble-Haeusslein
- Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA; Physical Therapy and Rehabilitation Sciences, University of California, San Francisco, CA 94143, USA
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108
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Hall AP. Review of the Pericyte during Angiogenesis and its Role in Cancer and Diabetic Retinopathy. Toxicol Pathol 2016; 34:763-75. [PMID: 17162534 DOI: 10.1080/01926230600936290] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Anthony P Hall
- AstraZeneca R&D Alderley Park, Safety Assessment UK, Mereside, Alderley Park, Macclesfield, SK10 4TG Cheshire, England.
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109
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Li L, Li YL, Zhou YF, Ge ZY, Wang LL, Li ZQ, Guo YJ, Jin L, Ren Y, Liu JX, Xu Y. Jiangtang Xiaozhi Recipe () prevents diabetic retinopathy in streptozotocin-induced diabetic rats. Chin J Integr Med 2016; 23:425-432. [PMID: 27338824 DOI: 10.1007/s11655-016-2595-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To evaluate the prevention effect of diabetic retinopathy of Jiangtang Xiaozhi Recipe (, JXR) in streptozotocin (STZ)-induced diabetic rats. METHODS Sprague-Dawley rats were randomly divided into normal control group and diabetic group. Rats in the diabetic group were induced by intraperitoneal administration of STZ (50 mg/kg), and subdivided into 5 groups. Rats in the diabetic control group were given saline; four treatment groups were given metformin (300 mg/kg), JXR (2, 4 and 8 g/kg) respectively for 8 weeks, while rats in the normal control group were injected with citrate buffer and given the same volume of vehicle. Body weight and food intake were measured every week. The hypoglycaemic effects were determined by testing fasting blood glucose (FBG) every other week, and hemoglobin A1c (HbA1c), insulin, and glucagon at the end of the treatment. The preventive effects of JXR on STZ-induced diabetic rats were determined by histopathological examination with hematoxylin and eosin staining, and periodic acid-schiff staining. The effects were further evaluated by serum superoxide dismutase (SOD) activity and malondialdehyde (MDA). RESULTS High-dose JXR significantly reduced FBG and HbA1c level at the 8th week of administration (P<0.01, P<0.05). JXR significantly increased insulin level (P<0.05), and decreased glucagon level (P<0.05). JXR showed the antioxidant defense with increased SOD activity and decreased MDA contents in diabetic rats. Histopathological studies revealed that there were no basement membrane thickening and mild destruction in the treated groups. Morphometric measurements of retina microvascular showed that acellular capillary and capillary density decreased in treated rats while pericyte and endothelial cell increasing after the treatment. CONCLUSION JXR have protective effect of diabetic retinopathy and its mechanism may be associated with the obvious hypoglycemic and antioxidant effect.
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Affiliation(s)
- Lin Li
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Yan-Lin Li
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Yun-Feng Zhou
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Zheng-Yan Ge
- Experiment Research Center, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
| | - Li-Li Wang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Zhi-Qiang Li
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Yu-Jie Guo
- Experiment Research Center, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
| | - Long Jin
- Experiment Research Center, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
| | - Ye Ren
- Experiment Research Center, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
| | - Jian-Xun Liu
- Experiment Research Center, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
| | - Yang Xu
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China.
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110
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Kinstlinger IS, Miller JS. 3D-printed fluidic networks as vasculature for engineered tissue. LAB ON A CHIP 2016; 16:2025-43. [PMID: 27173478 DOI: 10.1039/c6lc00193a] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Fabrication of vascular networks within engineered tissue remains one of the greatest challenges facing the fields of biomaterials and tissue engineering. Historically, the structural complexity of vascular networks has limited their fabrication in tissues engineered in vitro. Recently, however, key advances have been made in constructing fluidic networks within biomaterials, suggesting a strategy for fabricating the architecture of the vasculature. These techniques build on emerging technologies within the microfluidics community as well as on 3D printing. The freeform fabrication capabilities of 3D printing are allowing investigators to fabricate fluidic networks with complex architecture inside biomaterial matrices. In this review, we examine the most exciting 3D printing-based techniques in this area. We also discuss opportunities for using these techniques to address open questions in vascular biology and biophysics, as well as for engineering therapeutic tissue substitutes in vitro.
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Affiliation(s)
| | - Jordan S Miller
- Department of Bioengineering, Rice University, Houston, TX, USA.
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111
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Consumption of polyphenol-rich Morus alba leaves extract attenuates early diabetic retinopathy: the underlying mechanism. Eur J Nutr 2016; 56:1671-1684. [DOI: 10.1007/s00394-016-1214-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Accepted: 03/31/2016] [Indexed: 01/22/2023]
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112
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Angiopoietin 2 induces astrocyte apoptosis via αvβ5-integrin signaling in diabetic retinopathy. Cell Death Dis 2016; 7:e2101. [PMID: 26890140 PMCID: PMC5399183 DOI: 10.1038/cddis.2015.347] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 10/04/2015] [Accepted: 11/02/2015] [Indexed: 12/04/2022]
Abstract
The vascular leakage in diabetic retinopathy leads to macular edema and vision loss. Although astrocyte play an important role in regulating blood-brain barrier integrity in the brain, the precise role of astrocyte in blood-retinal barrier was yet to be elucidated. This study aimed to investigate the role of angiopoietin 2 (Ang2) in astrocyte loss and vascular leakage in the early streptozotocin-induced diabetic retinopathy. We demonstrated that vascular leakage occurred with astrocyte loss in early diabetic mice retina as Ang2 increased. The astrocyte loss and vascular leakage were inhibited by intravitreal injection of Ang2-neutralizing antibody. In vitro, Ang2 aggravated high glucose-induced astrocyte apoptosis via GSK-3β activation. Ang2 directly bound to αvβ5 integrin, which was abundant in astrocyte, and the blockade of αvβ5 integrin, in vitro, effectively attenuated Ang2-induced astrocyte apoptosis. In vivo, intravitreal injection of anti-αvβ5-integrin antibody inhibited astrocyte loss in early diabetic retinopathy. Taken together, Ang2 induced astrocyte apoptosis under high glucose via αvβ5-integrin/GSK-3β/β-catenin pathway. Therefore, we suggest that Ang2/integrin signaling could be a potential therapeutic target to prevent the vascular leakage by astrocyte loss in early diabetic retinopathy.
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Trost A, Lange S, Schroedl F, Bruckner D, Motloch KA, Bogner B, Kaser-Eichberger A, Strohmaier C, Runge C, Aigner L, Rivera FJ, Reitsamer HA. Brain and Retinal Pericytes: Origin, Function and Role. Front Cell Neurosci 2016; 10:20. [PMID: 26869887 PMCID: PMC4740376 DOI: 10.3389/fncel.2016.00020] [Citation(s) in RCA: 158] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 01/18/2016] [Indexed: 12/13/2022] Open
Abstract
Pericytes are specialized mural cells located at the abluminal surface of capillary blood vessels, embedded within the basement membrane. In the vascular network these multifunctional cells fulfil diverse functions, which are indispensable for proper homoeostasis. They serve as microvascular stabilizers, are potential regulators of microvascular blood flow and have a central role in angiogenesis, as they for example regulate endothelial cell proliferation. Furthermore, pericytes, as part of the neurovascular unit, are a major component of the blood-retina/brain barrier. CNS pericytes are a heterogenic cell population derived from mesodermal and neuro-ectodermal germ layers acting as modulators of stromal and niche environmental properties. In addition, they display multipotent differentiation potential making them an intriguing target for regenerative therapies. Pericyte-deficiencies can be cause or consequence of many kinds of diseases. In diabetes, for instance, pericyte-loss is a severe pathological process in diabetic retinopathy (DR) with detrimental consequences for eye sight in millions of patients. In this review, we provide an overview of our current understanding of CNS pericyte origin and function, with a special focus on the retina in the healthy and diseased. Finally, we highlight the role of pericytes in de- and regenerative processes.
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Affiliation(s)
- Andrea Trost
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and OptometrySalzburg, Austria; Molecular Regenerative Medicine, Paracelsus Medical UniversitySalzburg, Austria
| | - Simona Lange
- Molecular Regenerative Medicine, Paracelsus Medical UniversitySalzburg, Austria; Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University SalzburgSalzburg, Austria
| | - Falk Schroedl
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and OptometrySalzburg, Austria; Anatomy, Paracelsus Medical UniversitySalzburg, Austria
| | - Daniela Bruckner
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and Optometry Salzburg, Austria
| | - Karolina A Motloch
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and Optometry Salzburg, Austria
| | - Barbara Bogner
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and Optometry Salzburg, Austria
| | - Alexandra Kaser-Eichberger
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and Optometry Salzburg, Austria
| | - Clemens Strohmaier
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and Optometry Salzburg, Austria
| | - Christian Runge
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and Optometry Salzburg, Austria
| | - Ludwig Aigner
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University SalzburgSalzburg, Austria; Anatomy, Paracelsus Medical UniversitySalzburg, Austria
| | - Francisco J Rivera
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University SalzburgSalzburg, Austria; Anatomy, Paracelsus Medical UniversitySalzburg, Austria
| | - Herbert A Reitsamer
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and OptometrySalzburg, Austria; Anatomy, Paracelsus Medical UniversitySalzburg, Austria
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Qiu Y, Zhao D, Butenschön VM, Bauer AT, Schneider SW, Skolnik EY, Hammes HP, Wieland T, Feng Y. Nucleoside diphosphate kinase B deficiency causes a diabetes-like vascular pathology via up-regulation of endothelial angiopoietin-2 in the retina. Acta Diabetol 2016; 53:81-9. [PMID: 25900369 DOI: 10.1007/s00592-015-0752-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 03/30/2015] [Indexed: 11/25/2022]
Abstract
AIMS Nucleoside diphosphate kinase B (NDPKB) is capable of maintaining the cellular nucleotide triphosphate pools. It might therefore supply UTP for the formation of UDP-GlcNAc from glucose. As NDPKB contributes to vascular dysfunction, we speculate that NDPKB might play a role in microangiopathies, such as diabetic retinopathy (DR). Therefore, we investigated the impact of NDPKB on retinal vascular damage using NDPKB(-/-) mice during development of DR and its possible mechanisms. METHODS Pericyte loss and acellular capillary (AC) formation were assessed in streptozotocin-induced diabetic NDPKB(-/-) and wild-type (WT) mice. Expression of angiopoietin-2 (Ang2) and protein N-acetylglucosamine modification (GlcNAcylation) were assessed by western blot and/or immunofluorescence in the diabetic retinas as well as in endothelial cells depleted of NDPKB by siRNA and stimulated with high glucose. RESULTS Similar to diabetic WT retinas, non-diabetic NDPKB(-/-) retinas showed a significant decrease in pericyte coverage in comparison with non-diabetic WT retinas. Hyperglycemia further aggravates pericyte loss in diabetic NDPKB(-/-) retinas. AC formation was detected in the diabetic NDPKB(-/-) retinas. Similar to hyperglycemia, NDPKB deficiency induced Ang2 expression and protein GlcNAcylation that were not further altered in the diabetic retinas. In cultured endothelial cells, stimulation with high glucose and NDPKB depletion comparably increased Ang2 expression and protein GlcNAcylation. CONCLUSIONS Our data identify NDPKB as a protective factor in the retina, which controls Ang2 expression and the hexosamine pathway. NDPKB-deficient mice are a suitable model for studying mechanisms underlying diabetic retinal vascular damage.
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Affiliation(s)
- Yi Qiu
- Institute for Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Mybachstr. 14, 68169, Mannheim, Germany
| | - Di Zhao
- Institute for Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Mybachstr. 14, 68169, Mannheim, Germany
| | - Vicki-Marie Butenschön
- Institute for Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Mybachstr. 14, 68169, Mannheim, Germany
| | - Alexander T Bauer
- Division of Experimental Dermatology, Department of Dermatology, Venereology, and Allergology, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Stefan W Schneider
- Division of Experimental Dermatology, Department of Dermatology, Venereology, and Allergology, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Edward Y Skolnik
- Division of Nephrology, New York University Langone Medical Center, 560 1st Ave, New York, NY, 10016, USA
| | - Hans-Peter Hammes
- 5th Medical Clinic, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Thomas Wieland
- Institute for Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Mybachstr. 14, 68169, Mannheim, Germany
| | - Yuxi Feng
- Institute for Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Mybachstr. 14, 68169, Mannheim, Germany.
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115
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Sharma SH, Thulasingam S, Nagarajan S. Chemopreventive agents targeting tumor microenvironment. Life Sci 2016; 145:74-84. [DOI: 10.1016/j.lfs.2015.12.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 12/01/2015] [Accepted: 12/05/2015] [Indexed: 02/07/2023]
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Cahoon JM, Rai RR, Carroll LS, Uehara H, Zhang X, O'Neil CL, Medina RJ, Das SK, Muddana SK, Olson PR, Nielson S, Walker K, Flood MM, Messenger WB, Archer BJ, Barabas P, Krizaj D, Gibson CC, Li DY, Koh GY, Gao G, Stitt AW, Ambati BK. Intravitreal AAV2.COMP-Ang1 Prevents Neurovascular Degeneration in a Murine Model of Diabetic Retinopathy. Diabetes 2015; 64:4247-59. [PMID: 26340930 PMCID: PMC4657578 DOI: 10.2337/db14-1030] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 08/23/2015] [Indexed: 12/22/2022]
Abstract
Diabetic retinopathy (DR) is the leading cause of blindness in the working-age population in the U.S. The vision-threatening processes of neuroglial and vascular dysfunction in DR occur in concert, driven by hyperglycemia and propelled by a pathway of inflammation, ischemia, vasodegeneration, and breakdown of the blood retinal barrier. Currently, no therapies exist for normalizing the vasculature in DR. Here, we show that a single intravitreal dose of adeno-associated virus serotype 2 encoding a more stable, soluble, and potent form of angiopoietin 1 (AAV2.COMP-Ang1) can ameliorate the structural and functional hallmarks of DR in Ins2Akita mice, with sustained effects observed through six months. In early DR, AAV2.COMP-Ang1 restored leukocyte-endothelial interaction, retinal oxygenation, vascular density, vascular marker expression, vessel permeability, retinal thickness, inner retinal cellularity, and retinal neurophysiological response to levels comparable with nondiabetic controls. In late DR, AAV2.COMP-Ang1 enhanced the therapeutic benefit of intravitreally delivered endothelial colony-forming cells by promoting their integration into the vasculature and thereby stemming further visual decline. AAV2.COMP-Ang1 single-dose gene therapy can prevent neurovascular pathology, support vascular regeneration, and stabilize vision in DR.
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Affiliation(s)
- Judd M Cahoon
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Ruju R Rai
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Lara S Carroll
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Hironori Uehara
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Xiaohui Zhang
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Christina L O'Neil
- Centre for Vision and Vascular Science, Queen's University Belfast, Belfast, Ireland
| | - Reinhold J Medina
- Centre for Vision and Vascular Science, Queen's University Belfast, Belfast, Ireland
| | - Subtrata K Das
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Santosh K Muddana
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Paul R Olson
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Spencer Nielson
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Kortnie Walker
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Maggie M Flood
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Wyatt B Messenger
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Bonnie J Archer
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Peter Barabas
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - David Krizaj
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | | | - Dean Y Li
- Program in Molecular Medicine, Department of Medicine, University of Utah, Salt Lake City, UT
| | - Gou Y Koh
- Korean Advanced Institute for Science and Technology, Daejeon, South Korea
| | - Guangping Gao
- Department of Molecular Genetics and Microbiology, University of Massachusetts, Worcester, MA
| | - Alan W Stitt
- Centre for Vision and Vascular Science, Queen's University Belfast, Belfast, Ireland
| | - Balamurali K Ambati
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT
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Carvalho LJDM, Moreira ADS, Daniel-Ribeiro CT, Martins YC. Vascular dysfunction as a target for adjuvant therapy in cerebral malaria. Mem Inst Oswaldo Cruz 2015; 109:577-88. [PMID: 25185000 PMCID: PMC4156451 DOI: 10.1590/0074-0276140061] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 04/02/2014] [Indexed: 12/27/2022] Open
Abstract
Cerebral malaria (CM) is a life-threatening complication of Plasmodium
falciparum malaria that continues to be a major global health problem.
Brain vascular dysfunction is a main factor underlying the pathogenesis of CM and can
be a target for the development of adjuvant therapies for the disease. Vascular
occlusion by parasitised red blood cells and vasoconstriction/vascular dysfunction
results in impaired cerebral blood flow, ischaemia, hypoxia, acidosis and death. In
this review, we discuss the mechanisms of vascular dysfunction in CM and the roles of
low nitric oxide bioavailability, high levels of endothelin-1 and dysfunction of the
angiopoietin-Tie2 axis. We also discuss the usefulness and relevance of the murine
experimental model of CM by Plasmodium berghei ANKA to identify
mechanisms of disease and to screen potential therapeutic interventions.
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Affiliation(s)
| | - Aline da Silva Moreira
- Laboratório de Pesquisas em Malária, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil
| | | | - Yuri Chaves Martins
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY, USA
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118
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Murugesan N, Üstunkaya T, Feener EP. Thrombosis and Hemorrhage in Diabetic Retinopathy: A Perspective from an Inflammatory Standpoint. Semin Thromb Hemost 2015; 41:659-64. [PMID: 26305236 PMCID: PMC4765320 DOI: 10.1055/s-0035-1556731] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Retinal ischemia and hemorrhage are hallmarks of worsening diabetic retinopathy, which can lead to neovascularization, macular edema, and severe vision loss. Although diabetes alters expression of clotting factors and their activities, and increases retinal microthromboses, the effects of thrombotic processes on the pathogenesis of diabetic retinopathy are not fully understood. In addition to the roles of coagulation and fibrinolytic cascades in thrombosis and hemostasis, components in these systems also mediate multiple effects on the vasculature that promote inflammation. Plasma kallikrein, thrombin, and urokinase are increased in diabetic retinopathy, and exert proinflammatory effects that contribute to retinal vascular dysfunction. The accumulation and activation of these and additional coagulation factors in the vitreous due to hemorrhage and chronic retinal injury in the diabetic retina may contribute to worsening of retinal inflammation and capillary dysfunction, which lead to retinal ischemia and edema. Further understanding of the role for specific coagulation factors in diabetic retinopathy may suggest new therapeutic opportunities for this vision-threatening disease.
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Affiliation(s)
- Nivetha Murugesan
- Joslin Diabetes Center, Boston, MA
- Department of Medicine, Harvard Medical School, Boston, MA
| | | | - Edward P. Feener
- Joslin Diabetes Center, Boston, MA
- Department of Medicine, Harvard Medical School, Boston, MA
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119
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Gopinathan G, Milagre C, Pearce OMT, Reynolds LE, Hodivala-Dilke K, Leinster DA, Zhong H, Hollingsworth RE, Thompson R, Whiteford JR, Balkwill F. Interleukin-6 Stimulates Defective Angiogenesis. Cancer Res 2015; 75:3098-107. [PMID: 26081809 PMCID: PMC4527186 DOI: 10.1158/0008-5472.can-15-1227] [Citation(s) in RCA: 175] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 05/13/2015] [Indexed: 12/19/2022]
Abstract
The cytokine IL6 has a number of tumor-promoting activities in human and experimental cancers, but its potential as an angiogenic agent has not been fully investigated. Here, we show that IL6 can directly induce vessel sprouting in the ex vivo aortic ring model, as well as endothelial cell proliferation and migration, with similar potency to VEGF. However, IL6-stimulated aortic ring vessel sprouts had defective pericyte coverage compared with VEGF-stimulated vessels. The mechanism of IL6 action on pericytes involved stimulation of the Notch ligand Jagged1 as well as angiopoietin2 (Ang2). When peritoneal xenografts of ovarian cancer were treated with an anti-IL6 antibody, pericyte coverage of vessels was restored. In addition, in human ovarian cancer biopsies, there was an association between levels of IL6 mRNA, Jagged1, and Ang2. Our findings have implications for the use of cancer therapies that target VEGF or IL6 and for understanding abnormal angiogenesis in cancers, chronic inflammatory disease, and stroke.
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Affiliation(s)
- Ganga Gopinathan
- Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London, United Kingdom
| | - Carla Milagre
- Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London, United Kingdom
| | - Oliver M T Pearce
- Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London, United Kingdom
| | - Louise E Reynolds
- Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London, United Kingdom
| | - Kairbaan Hodivala-Dilke
- Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London, United Kingdom
| | - David A Leinster
- Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London, United Kingdom
| | - Haihong Zhong
- MedImmune, One MedImmune Way, Gaithersburg, Maryland
| | | | - Richard Thompson
- Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London, United Kingdom
| | - James R Whiteford
- William Harvey Institute, Queen Mary University of London, Charterhouse Square, London, United Kingdom
| | - Frances Balkwill
- Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London, United Kingdom.
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120
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Jang JW, Cho YJ, Kim HJ, Kim JM, Lee SJ, Kwon OW, Kim DS. Blood Vessel Maturation by Disintegrin in Oxygen-Induced Retinopathy. Curr Eye Res 2015. [PMID: 26200105 DOI: 10.3109/02713683.2015.1050737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE Although Arg-Gly-Asp (RGD) motif-containing disintegrins are associated with integrin inhibition and the activation of various biological processes, little is known about the role of RGD motif-containing disintegrin in vascular development and remodeling. We therefore investigated the role of RGD-containing disintegrin in vascular remodeling in oxygen-induced retinopathy (OIR) mouse model. MATERIALS AND METHODS EGT022, an RGD-containing disintegrin originated from human a disintegrin and metalloproteinase 15 (ADAM15), was used to investigate the role of the disintegrin in vascular development in OIR mouse model. To analyze the functional effects of EGT022 on retinal vascular development, the immunohistochemistry on mouse retinas after fluorescein isothiocyanate (FITC) perfusion was conducted and the vessel integrity was examined using modified Mile's permeability assay. RESULTS EGT022 was able to reduce overall retinopathy scores by 75%, indicating its efficacy in retinal microvessel maturation stimulation. Pericyte coverage was greatly stimulated by EGT022 treatment in OIR mouse model. EGT022 was also effective to significantly improve blood vessel integrity. CONCLUSIONS RGD-containing disintegrin EGT022 stimulated vascular maturation in OIR mouse model. Experimental results suggest that EGT022 is useful for treatments to improve ischemia in nonproliferative diabetic retinopathy (NPDR), the early stage of diabetic retinopathy.
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Affiliation(s)
- Jin-Wook Jang
- a R&D Center, EyeGene Inc. , Seoul , Republic of Korea .,b Department of Biochemistry , College of Life Science and Biotechnology, Yonsei University , Seoul , Korea
| | - Yang Je Cho
- a R&D Center, EyeGene Inc. , Seoul , Republic of Korea
| | - Hyun Jong Kim
- a R&D Center, EyeGene Inc. , Seoul , Republic of Korea
| | - Jong Min Kim
- a R&D Center, EyeGene Inc. , Seoul , Republic of Korea
| | - Sung Jin Lee
- c Department of Ophthalmology , Soonchunhyang University College of Medicine , Seoul , Korea and
| | | | - Doo-Sik Kim
- b Department of Biochemistry , College of Life Science and Biotechnology, Yonsei University , Seoul , Korea
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121
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Abstract
Pericytes enveloping the endothelium play an important role in the physiology and pathology of microvessels, especially in vessel maturation and stabilization. However, our understanding of fundamental pericyte biology is limited by the lack of a robust in vitro model system that allows researchers to evaluate the interactions among multiple cell types in perfusable blood vessels. The present work describes a microfluidic platform that can be used to investigate interactions between pericytes and endothelial cells (ECs) during the sprouting, growth, and maturation steps of neovessel formation. A mixture of ECs and pericytes was attached to the side of a pre-patterned three dimensional fibrin matrix and allowed to sprout across the matrix. The effects of intact coverage and EC maturation by the pericytes on the perfused EC network were confirmed using a confocal microscope. Compared with EC monoculture conditions, EC-pericyte co-cultured vessels showed a significant reduction in diameter, increased numbers of junctions and branches and decreased permeability. In response to biochemical factors, ECs and pericytes in the platform showed the similar features with previous reports from in vivo experiments, thus reflect various pathophysiological conditions of in vivo microvessels. Taken together, these results support the physiological relevancy of our three-dimensional microfluidic culture system but also that the system can be used to screen drug effect on EC-pericyte biology.
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Affiliation(s)
- Jaerim Kim
- Division of WCU Multiscale Mechanical Design, School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Republic of Korea
| | - Minhwan Chung
- School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Republic of Korea
| | - Sudong Kim
- School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Republic of Korea
| | - Dong Hyun Jo
- Fight against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Biomedical Sciences and Protein Metabolism Medical Research Center, College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Jeong Hun Kim
- Fight against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Biomedical Sciences and Protein Metabolism Medical Research Center, College of Medicine, Seoul National University, Seoul, Republic of Korea
- Department of Ophthalmology, College of Medicine, Seoul National University, Seoul, Republic of Korea
- * E-mail: (NLJ); (JHK)
| | - Noo Li Jeon
- Division of WCU Multiscale Mechanical Design, School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Republic of Korea
- School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Republic of Korea
- Institute of Advanced Machinery and Design, Seoul National University, Seoul, Republic of Korea
- * E-mail: (NLJ); (JHK)
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122
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A review of therapies for diabetic macular oedema and rationale for combination therapy. Eye (Lond) 2015; 29:1115-30. [PMID: 26113500 DOI: 10.1038/eye.2015.110] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 05/06/2015] [Indexed: 12/23/2022] Open
Abstract
Diabetic macular oedema (DMO) is responsible for significant visual impairment in diabetic patients. The primary cause of DMO is fluid leakage resulting from increased vascular permeability through contributory anatomical and biochemical changes. These include endothelial cell (EC) death or dysfunction, pericyte loss or dysfunction, thickened basement membrane, loss or dysfunction of glial cells, and loss/change of EC Glycocalyx. The molecular changes include increased reactive oxygen species, pro-inflammatory changes: advanced glycation end products, intracellular adhesion molecule-1, Complement 5-9 deposition and cytokines, which result in increased paracellular permeability, tight junction disruption, and increased transcellular permeability. Laser photocoagulation has been the mainstay of treatment until recently when pharmacological treatments were introduced. The current treatments for DMO target reducing vascular leak in the macula once it has occurred, they do not attempt to treat the underlying pathology. These pharmacological treatments are aimed at antagonising vascular endothelial growth factor (VEGF) or non-VEGF inflammatory pathways, and include intravitreal injections of anti-VEGFs (ranibizumab, aflibercept or bevacizumab) or steroids (fluocinolone, dexamethasone or triamcinolone) as single therapies. The available evidence suggests that each individual treatment modality in DMO does not result in a completely dry macula in most cases. The ideal treatment for DMO should improve vision and improve morphological changes in the macular (eg, reduce macular oedema) for a significant duration, reduced adverse events, reduced treatment burden and costs, and be well tolerated by patients. This review evaluates the individual treatments available as monotherapies, and discusses the rationale and potential for combination therapy in DMO. A comprehensive review of clinical trials related to DMO and their outcomes was completed. Where phase III randomised control trials were available, these were referenced, if not available, phase II trials have been included.
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123
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Abstract
Chronic rejection of transplanted organs remains the main obstacle in the long-term success of organ transplantation. Thus, there is a persistent quest for development of antichronic rejection therapies and identification of novel molecular and cellular targets. One of the potential targets is the pericytes, the mural cells of microvessels, which regulate microvascular permeability, development, and maturation by controlling endothelial cell functions and regulating tissue fibrosis and inflammatory response. In this review, we discuss the potential of targeting pericytes in the development of microvasular dysfunction and the molecular pathways involved in regulation of pericyte activities for antichronic rejection intervention.
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124
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Braunger BM, Leimbeck SV, Schlecht A, Volz C, Jägle H, Tamm ER. Deletion of ocular transforming growth factor β signaling mimics essential characteristics of diabetic retinopathy. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:1749-68. [PMID: 25857227 DOI: 10.1016/j.ajpath.2015.02.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 12/22/2014] [Accepted: 02/03/2015] [Indexed: 01/16/2023]
Abstract
Diabetic retinopathy, a major cause of blindness, is characterized by a distinct phenotype. The molecular causes of the phenotype are not sufficiently clear. Here, we report that deletion of transforming growth factor β signaling in the retinal microenvironment of newborn mice induces changes that largely mimic the phenotype of nonproliferative and proliferative diabetic retinopathy in humans. Lack of transforming growth factor β signaling leads to the formation of abundant microaneurysms, leaky capillaries, and retinal hemorrhages. Retinal capillaries are not covered by differentiated pericytes, but by a coat of vascular smooth muscle-like cells and a thickened basal lamina. Reactive microglia is found in close association with retinal capillaries. In older animals, loss of endothelial cells and the formation of ghost vessels are observed, findings that correlate with the induction of angiogenic molecules and the accumulation of retinal hypoxia-inducible factor 1α, indicating hypoxia. Consequently, retinal and vitreal neovascularization occurs, a scenario that leads to retinal detachment, vitreal hemorrhages, neuronal apoptosis, and impairment of sensory function. We conclude that transforming growth factor β signaling is required for the differentiation of retinal pericytes during vascular development of the retina. Lack of differentiated pericytes initiates a scenario of structural and functional changes in the retina that mimics those of diabetic retinopathy strongly indicating a common mechanism.
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Affiliation(s)
- Barbara M Braunger
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany
| | - Sarah V Leimbeck
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany
| | - Anja Schlecht
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany
| | - Cornelia Volz
- Department of Ophthalmology, University of Regensburg, Regensburg, Germany
| | - Herbert Jägle
- Department of Ophthalmology, University of Regensburg, Regensburg, Germany
| | - Ernst R Tamm
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany.
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125
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van Dijk CGM, Nieuweboer FE, Pei JY, Xu YJ, Burgisser P, van Mulligen E, el Azzouzi H, Duncker DJ, Verhaar MC, Cheng C. The complex mural cell: pericyte function in health and disease. Int J Cardiol 2015; 190:75-89. [PMID: 25918055 DOI: 10.1016/j.ijcard.2015.03.258] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 03/16/2015] [Accepted: 03/18/2015] [Indexed: 02/06/2023]
Abstract
Pericytes are perivascular cells that can be distinguished from vascular smooth muscle cells by their specific morphology and expression of distinct molecular markers. Found in the microvascular beds distributed throughout the body, they are well known for their regulation of a healthy vasculature. In this review, we examine the mechanism of pericyte support to vasomotion, and the known pathways that regulate pericyte response in angiogenesis and neovascular stabilization. We will also discuss the role of pericytes in vascular basement membrane and endothelial barrier function regulation. In contrast, recent findings have indicated that pericyte dysfunction, characterized by changes in pericyte contractility or pericyte loss of microvascular coverage, plays an important role in onset and progression of vascular-related and fibrogenic diseases. From a therapeutic point of view, pericytes have recently been identified as a putative pool of endogenous mesenchymal stem cells that could be activated in response to tissue injury to contribute to the regenerative process on multiple levels. We will discuss the mechanisms via which pericytes are involved in disease onset and development in a number of pathophysiological conditions, as well as present the evidence that supports a role for multipotent pericytes in tissue regeneration. The emerging field of pericyte research will not only contribute to the identification of new drug targets in pericyte dysfunction associated diseases, but may also boost the use of this cell type in future cell-based regenerative strategies.
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Affiliation(s)
- Christian G M van Dijk
- Laboratory of Renal and Vascular Biology, Department of Nephrology and Hypertension, University Medical Center Utrecht, The Netherlands
| | - Frederieke E Nieuweboer
- Laboratory of Renal and Vascular Biology, Department of Nephrology and Hypertension, University Medical Center Utrecht, The Netherlands
| | - Jia Yi Pei
- Laboratory of Renal and Vascular Biology, Department of Nephrology and Hypertension, University Medical Center Utrecht, The Netherlands
| | - Yan Juan Xu
- Laboratory of Renal and Vascular Biology, Department of Nephrology and Hypertension, University Medical Center Utrecht, The Netherlands
| | - Petra Burgisser
- Department of Cardiology, University Medical Center Utrecht, The Netherlands
| | - Elise van Mulligen
- Laboratory of Renal and Vascular Biology, Department of Nephrology and Hypertension, University Medical Center Utrecht, The Netherlands
| | - Hamid el Azzouzi
- Department of Cardiology, University Medical Center Utrecht, The Netherlands
| | - Dirk J Duncker
- Department of Cardiology, Cardiovascular Research School COEUR, Erasmus University Medical Center Rotterdam, The Netherlands
| | - Marianne C Verhaar
- Laboratory of Renal and Vascular Biology, Department of Nephrology and Hypertension, University Medical Center Utrecht, The Netherlands
| | - Caroline Cheng
- Laboratory of Renal and Vascular Biology, Department of Nephrology and Hypertension, University Medical Center Utrecht, The Netherlands; Department of Cardiology, Cardiovascular Research School COEUR, Erasmus University Medical Center Rotterdam, The Netherlands.
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126
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Abstract
The endothelial TIE1 and TIE2 receptor tyrosine kinases form a distinct subfamily characterized by their unique extracellular domains. Together with the angiopoietin growth factors (ANGPT1, ANGPT2, ANGPT4, also abbreviated as ANG), the TIE receptors form an endothelial specific signaling pathway with important functions in the regulation of lymphatic and cardiovascular development and vascular homeostasis. Angiopoietins exist in multimeric forms that activate the TIE receptors via unique mechanism. In endothelial cell–cell contacts, angiopoietins induce the formation of homomeric in trans TIE receptor complexes extending across the cell junctions, whereas matrix-bound angiopoietin-1 (ANG1) activates the TIE receptors in a cis configuration. In comparison to the vascular endothelial growth factor receptors, the TIE receptors undergo little ubiquitin-mediated degradation after activation, whereas TIE2 signaling is negatively regulated by the vascular endothelial protein tyrosine phosphatase, VE-PTP. ANG1 activation of TIE2 supports vascular stabilization, whereas angiopoietin-2 (ANG2), a context-dependent weak TIE2 agonist/antagonist, promotes pathological tumor angiogenesis, vascular permeability, and inflammation. Recently, ANG2 has been found to mediate some of its vascular destabilizing and angiogenic functions via integrin signalling. The circulating levels of ANG2 are increased in cancer, and in several human diseases associated with inflammation and vascular leak, for example, in sepsis. Blocking of ANG2 has emerged as a potential novel therapeutic strategy for these diseases. In addition, preclinical results demonstrate that genetic TIE1 deletion in mice inhibits the vascularization and growth of tumor isografts and protects from atherosclerosis, with little effect on normal vascular homeostasis in adult mice. The ability of the ANG-TIE pathway to control vessel stability and angiogenesis makes it an interesting vascular target for the treatment of the various diseases.
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127
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Scholz A, Plate KH, Reiss Y. Angiopoietin-2: a multifaceted cytokine that functions in both angiogenesis and inflammation. Ann N Y Acad Sci 2015; 1347:45-51. [PMID: 25773744 DOI: 10.1111/nyas.12726] [Citation(s) in RCA: 162] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 01/19/2015] [Accepted: 01/23/2015] [Indexed: 12/12/2022]
Abstract
Angiogenesis and inflammation are two highly linked processes. In the last decade, several factors with dual function in both of these major pathways have been identified. This review focuses on angiopoietin-2 (Ang-2), an important proangiogenic factor that has more recently been implicated in mediating inflammatory processes as well. Ang-2 is upregulated in multiple inflammatory diseases and has been implicated in the direct control of inflammation-related signaling pathways. As a consequence of its multiple roles, designs for therapeutic targeting of Ang-2 should consider the dual function of this factor in regulating angiogenesis and inflammation.
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Affiliation(s)
- Alexander Scholz
- Department of Pathology, Laboratory of Immunology and Vascular Biology, Stanford University School of Medicine, Stanford, California
| | - Karl H Plate
- Edinger Institute/Institute of Neurology, Frankfurt University Medical School, Frankfurt, Germany.,German Center for Cardiovascular Research (DZHK), Frankfurt, Germany.,German Cancer Consortium (DKTK), Frankfurt, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Yvonne Reiss
- Edinger Institute/Institute of Neurology, Frankfurt University Medical School, Frankfurt, Germany.,German Center for Cardiovascular Research (DZHK), Frankfurt, Germany.,German Cancer Consortium (DKTK), Frankfurt, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
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128
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Arboleda-Velasquez JF, Valdez CN, Marko CK, D'Amore PA. From pathobiology to the targeting of pericytes for the treatment of diabetic retinopathy. Curr Diab Rep 2015; 15:573. [PMID: 25620405 PMCID: PMC5599150 DOI: 10.1007/s11892-014-0573-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Pericytes, the mural cells that constitute the capillaries along with endothelial cells, have been associated with the pathobiology of diabetic retinopathy; however, therapeutic implications of this association remain largely unexplored. Pericytes appear to be highly susceptible to the metabolic challenges associated with a diabetic environment, and there is substantial evidence that their loss may contribute to microvascular instability leading to the formation of microaneurysms, microhemorrhages, acellular capillaries, and capillary nonperfusion. Since pericytes are strategically located at the interface between the vascular and neural components of the retina, they offer extraordinary opportunities for therapeutic interventions in diabetic retinopathy. Moreover, the availability of novel imaging methodologies now allows for the in vivo visualization of pericytes, enabling a new generation of clinical trials that use pericyte tracking as clinical endpoints. The recognition of multiple signaling mechanisms involved in pericyte development and survival should allow for a renewed interest in pericytes as a therapeutic target for diabetic retinopathy.
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Affiliation(s)
- Joseph F Arboleda-Velasquez
- Schepens Eye Research Institute/Massachusetts Eye and Ear and the Department of Ophthalmology, Harvard Medical School, 20 Staniford Street, Boston, MA, 02114, USA
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Chen S, Li H, Zhang C, Li Z, Wang Q, Guo J, Luo C, Wang Y. Urinary angiopoietin-2 is associated with albuminuria in patients with type 2 diabetes mellitus. Int J Endocrinol 2015; 2015:163120. [PMID: 25873946 PMCID: PMC4383519 DOI: 10.1155/2015/163120] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 09/08/2014] [Accepted: 09/18/2014] [Indexed: 12/31/2022] Open
Abstract
Aims. To evaluate the levels of angiopoietin-1 (Ang-1), Ang-2, and vascular endothelial growth factor (VEGF) in serum and urine, and their association with albuminuria in patients with type 2 diabetes mellitus. Methods. In 113 type 2 diabetic patients with normoalbuminuria, microalbuminuria, and macroalbuminuria and 30 healthy controls, the levels of Ang-1, Ang-2, and VEGF in serum and urine were measured by enzyme-linked immunosorbent assay (ELISA). Results. Urinary and serum levels of Ang-2 were significantly higher in diabetic patients with normoalbuminuria than in healthy controls. Increased urinary Ang-2 level was positively associated with the degree of albuminuria. Urinary Ang-1 levels were significantly higher in normoalbuminuria patients and lower in macroalbuminuria patients than in controls. The levels of urinary VEGF increased in the albuminuria subgroup, though serum levels of Ang-1 and VEGF did not change. Urinary Ang-2 levels were correlated positively with albuminuria and negatively with glomerular filtration rate (GFR). Stepwise multiple regression analysis identified albuminuria (P < 0.001) and GFR (P = 0.001) as significant predictors of urinary Ang-2. Conclusions. Our data suggest that urinary Ang-2 is stepwise increased with renal damage in patients with type 2 diabetes mellitus and is associated with albuminuria.
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Affiliation(s)
- Shan Chen
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1277 Jiefang Avenue, Wuhan, Hubei 430022, China
| | - Huiqing Li
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China
| | - Chun Zhang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1277 Jiefang Avenue, Wuhan, Hubei 430022, China
| | - Zhenqiong Li
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1277 Jiefang Avenue, Wuhan, Hubei 430022, China
| | - Qiuyuan Wang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1277 Jiefang Avenue, Wuhan, Hubei 430022, China
| | - Jinting Guo
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1277 Jiefang Avenue, Wuhan, Hubei 430022, China
| | - Changqing Luo
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1277 Jiefang Avenue, Wuhan, Hubei 430022, China
| | - Yumei Wang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1277 Jiefang Avenue, Wuhan, Hubei 430022, China
- *Yumei Wang:
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Tuuminen R, Haukka J, Loukovaara S. Statins in rhegmatogenous retinal detachment are associated with low intravitreal angiopoietin-2, VEGF and MMP-2 levels, and improved visual acuity gain in vitrectomized patients. Graefes Arch Clin Exp Ophthalmol 2014; 253:1685-93. [PMID: 25432094 DOI: 10.1007/s00417-014-2873-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 10/22/2014] [Accepted: 11/19/2014] [Indexed: 01/08/2023] Open
Abstract
PURPOSE In rhegmatogenous retinal detachment (RRD), intravitreal growth factors and cytokines may compromise post-vitrectomy outcomes. Here, we analysed perioperative intravitreal protein levels of potent vasoactive, pro-inflammatory, and extracellular matrix-remodelling factors in RRD eyes of patients treated with statins and evaluated post-vitrectomy outcome in the same study eyes. METHODS Institutional, retrospective, observational study of 14 patients operated on for RRD while on statins compared to patients without statin medication (n = 82). Vitreous samples were subjected to protein measurements of angiopoietin (ANGPT)-1 and -2, transforming growth factor-β1, and vascular endothelial growth factor (VEGF) by ELISA, and of matrix metalloproteinase (MMP)-2 and -9 by gelatin zymography. A 1-month best-corrected visual acuity (BCVA) gain was modelled by Student's T-test and multivariate linear regression with concomitant perioperative medication. Cumulative 12-month revitrectomy frequency was modelled by Kaplan-Meier log-rank test. RESULTS Intravitreal levels of ANGPT-2 (49.2 ± 33.1 vs. 112.8 ± 134.1 pg/ml, mean ± SD, p < 0.001), VEGF (2.3 ± 2.4 vs. 17.7 ± 57.8 pg/ml, p = 0.021), and MMP-2 (1107.1 ± 884.6 vs 1976.4 ± 970.1 AU/ml, p = 0.005) in RRD eyes of patients treated with statins were lower than in non-statin-treated controls. Patients on statins had better 1-month BCVA improvement than did those not on statins (p = 0.022), with no difference in 1-year re-vitrectomy rates. CONCLUSIONS Intravitreal levels of ANGPT-2, VEGF, factors involved in vascular permeability and inflammation, and activity of MMP-2, the factor connected with breakdown of basement membrane and fibroproliferation, were lower in RRD eyes of patients with statin treatment. At 1-month, postoperative BCVA gain was improved in statin-treated RRD eyes, suggesting that statin administration may be effective in preventing inflammation-related PVR formation.
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Affiliation(s)
- Raimo Tuuminen
- Department of Ophthalmology, Helsinki University Central Hospital, Haartmaninkatu 4 C, FI-00290, Helsinki, Finland
| | - Jari Haukka
- Hjelt Institute, Faculty of Medicine, University of Helsinki, Haartmaninkatu 4 C, FI-00290, Helsinki, Finland
| | - Sirpa Loukovaara
- Unit of Vitreoretinal Surgery, Department of Ophthalmology, Helsinki University Central Hospital, Haartmaninkatu 4 C, FI-00290, Helsinki, Finland.
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131
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Gandica Y, Schwarz T, Oliveira O, Travasso RDM. Hypoxia in vascular networks: a complex system approach to unravel the diabetic paradox. PLoS One 2014; 9:e113165. [PMID: 25409306 PMCID: PMC4237512 DOI: 10.1371/journal.pone.0113165] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 10/20/2014] [Indexed: 01/30/2023] Open
Abstract
In this work we model the extent of hypoxia in the diabetic retina as a function of the area affected by vessel disruption. We find two regimes that differ on the ratio between the area of disrupted vasculature and the area of tissue in hypoxia. In the first regime the hypoxia is localized in the vicinity of the vascular disruption, while in the second regime there is a generalized hypoxia in the affected tissue. The transition between these two regimes occurs when the tissue area affected by individual sites of vessel damage is on the order of the square of the characteristic irrigation length in the tissue (the maximum distance that an irrigated point in the tissue is from an existing vessel). We observe that very high levels of hypoxia are correlated with the rupture of larger vessels in the retina, and with smaller radii of individual sites of vessel damage. Based on this property of vascular networks, we propose a novel mechanism for the transition between the nonproliferative and the proliferative stages in diabetic retinopathy.
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Affiliation(s)
- Yérali Gandica
- Center for Computational Physics, Department of Physics, University of Coimbra, Coimbra, Portugal
| | - Tobias Schwarz
- Center for Computational Physics, Department of Physics, University of Coimbra, Coimbra, Portugal
- Heinz-Brandt-Schule, Berlin, Germany
| | - Orlando Oliveira
- Center for Computational Physics, Department of Physics, University of Coimbra, Coimbra, Portugal
| | - Rui D. M. Travasso
- Center for Computational Physics, Department of Physics, University of Coimbra, Coimbra, Portugal
- Center of Ophthalmology and Vision Sciences(COCV), Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
- * E-mail:
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Abstract
miRNAs are highly conserved non-coding RNA molecules that negatively control gene expression by binding to target mRNAs promoting their degradation. A multitude of miRNAs have been reported to be involved in angiogenesis and vascular remodelling. In the present review, we aim to describe the effect of miRNAs in post-ischaemic repair. First, we describe the miRNAs reported in ischaemic diseases and in angiogenesis. Then we examine their capacity to modulate the behaviour of stem and progenitor cells which could be utilized for vascular repair. And finally we discuss the potential of miRNAs as new clinical biomarkers and therapeutic targets.
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133
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Tuuminen R, Sahanne S, Loukovaara S. Low intravitreal angiopoietin-2 and VEGF levels in vitrectomized diabetic patients with simvastatin treatment. Acta Ophthalmol 2014; 92:675-81. [PMID: 24506800 DOI: 10.1111/aos.12363] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 01/04/2014] [Indexed: 12/24/2022]
Abstract
PURPOSE To investigate the intravitreal levels of potent vasoactive, angiogenic and extracellular matrix remodelling factors in the diabetic patients with simvastatin treatment. METHODS This is an institutional, prospective, observational case-control study. Type-1 and type-2 diabetic patients on lipophilic simvastatin (N = 14) compared with patients without statin medication (N = 50). Vitreous samples were subjected to protein measurements of angiopoietin (Ang)-1 and Ang-2, erythropoietin (EPO), transforming growth factor (TGF)-β1, vascular endothelial growth factor (VEGF) by ELISA and matrix metalloproteinase (MMP)-2 and MMP-9 by gelatin zymography. RESULTS Intravitreal levels of Ang-2 (p = 0.029), VEGF (p = 0.001) and proMMP-9 (p = 0.015) were lower in simvastatin-treated than in non-statin-treated controls. In diabetics with macular oedema (DME), intravitreal Ang-2 (p = 0.006) and VEGF (p = 0.002) levels were lower in simvastatin-treated patients compared with non-statin-treated controls. In those patients with proliferative diabetic retinopathy (PDR), intravitreal Ang-2 (p = 0.002), TGF-β1 (p = 0.037), VEGF (p = 0.001) and pro- and totalMMP-9 (p = 0.004 and p = 0.007) levels were lower when receiving simvastatin medication. CONCLUSIONS In diabetic patients with DME or PDR, the intravitreal levels of permeability and proangiogenic factors Ang-2 and VEGF were lower in simvastatin-treated than in those without statin medication. Moreover, the levels of MMP-9 and TGF-β1, factors involved in the breakdown of basement membrane and fibroproliferation, were lower in patients with PDR having simvastatin medication. When acetylsalicylic acid was combined with simvastatin treatment, the intraocular levels of Ang-2 and VEGF were significantly lower than in diabetics treated with simvastatin alone. These data provide a novel insight into the potential protective mechanisms underlying simvastatin medication in patients with diabetic retinopathy complications.
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Affiliation(s)
- Raimo Tuuminen
- Department of Ophthalmology; Helsinki University Central Hospital; Helsinki Finland
| | - Sari Sahanne
- Department of Anesthesiology and Intensive Care Medicine; Eye-ENT Hospital; Helsinki University Central Hospital; Helsinki Finland
| | - Sirpa Loukovaara
- Department of Ophthalmology; Unit of Vitreoretinal Surgery; Helsinki University Central Hospital; Helsinki Finland
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134
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Park SW, Yun JH, Kim JH, Kim KW, Cho CH, Kim JH. Angiopoietin 2 induces pericyte apoptosis via α3β1 integrin signaling in diabetic retinopathy. Diabetes 2014; 63:3057-68. [PMID: 24722242 DOI: 10.2337/db13-1942] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Pericyte loss is an early characteristic change in diabetic retinopathy (DR). Despite accumulating evidence that hyperglycemia-induced angiopoietin 2 (Ang2) has a central role in pericyte loss, the precise molecular mechanism has not been elucidated. This study investigated the role of Ang2 in pericyte loss in DR. We demonstrated that pericyte loss occurred with Ang2 increase in the diabetic mouse retina and that the source of Ang2 could be the endothelial cell. Ang2 induced pericyte apoptosis via the p53 pathway under high glucose, whereas Ang2 alone did not induce apoptosis. Integrin, not Tie-2 receptor, was involved for Ang2-induced pericyte apoptosis under high glucose as an Ang2 receptor. High glucose changed the integrin expression pattern, which increased integrin α3 and β1 in the pericyte. Furthermore, Ang2-induced pericyte apoptosis in vitro was effectively attenuated via p53 suppression by blocking integrin α3 and β1. Although intravitreal injection of Ang2 induced pericyte loss in C57BL/6J mice retina in vivo, intravitreal injection of anti-integrin α3 and β1 antibodies attenuated Ang2-induced pericyte loss. Taken together, Ang2 induced pericyte apoptosis under high glucose via α3β1 integrin. Glycemic control or blocking Ang2/integrin signaling could be a potential therapeutic target to prevent pericyte loss in early DR.
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Affiliation(s)
- Sung Wook Park
- Fight against Angiogenesis-Related Blindness Laboratory, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Korea
| | - Jang-Hyuk Yun
- Department of Pharmacology and Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National University, Seoul, Korea Cancer Research Institute, College of Medicine, Seoul National University, Seoul, Korea
| | - Jin Hyoung Kim
- Fight against Angiogenesis-Related Blindness Laboratory, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Kyu-Won Kim
- Department of Pharmacy, Seoul National University, Seoul, Korea
| | - Chung-Hyun Cho
- Department of Pharmacology and Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National University, Seoul, Korea Cancer Research Institute, College of Medicine, Seoul National University, Seoul, Korea
| | - Jeong Hun Kim
- Fight against Angiogenesis-Related Blindness Laboratory, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Korea Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea
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135
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Taurine prevents high glucose-induced angiopoietin-2/tie-2 system alterations and apoptosis in retinal microvascular pericytes. Mol Cell Biochem 2014; 396:239-48. [PMID: 25060907 DOI: 10.1007/s11010-014-2159-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 07/14/2014] [Indexed: 10/25/2022]
Abstract
Previously, we confirmed that taurine prevented diabetes-induced apoptosis in retinal glial cells via its anti-oxidation and anti-glutamate excitotoxicity mechanisms. The aim of this study is to investigate the effects of taurine on angiopoietin-2 (Ang-2)/Tie-2 system expressions and apoptosis in high glucose-treated retinal microvascular pericytes (RMPs). Also, the possible mechanism involved in the inhibition of taurine on RMPs apoptosis is investigated. The expressions of Ang-2, Tie-2 were detected by qRT-PCR and ELISA. The level of phosphorylated Tie-2 (P-Tie-2) was examined by ELISA. Hoechst 33342 and Annexin V/PI staining were used to detect RMPs apoptosis. The activity of caspase-3 was detected by assay kit. In 25 mM high glucose group, the expression of Ang-2 was increased significantly, taurine down-regulated Ang-2 in a dose (0.1, 1, and 10 mM)-dependent manner (P < 0.05). The Tie-2 expression and P-Tie-2 level were decreased in high glucose group (P < 0.05). Interestingly, taurine at 1 and 10 mM showed significant increase in Tie-2 expression and P-Tie-2 level (P < 0.05). The number of apoptotic RMPs and the activity of caspase-3 increased in the presence of high glucose (P < 0.05). Treatment with taurine at 1 mM decreased the number of apoptotic RMPs and the activity of caspase-3 (P < 0.05). Blocking antibody and small interfering RNA (siRNA) treatment showed that taurine required Tie-2 to perform its anti-apoptotic effect. Taken together, our data suggest that high glucose-induced Ang-2/Tie-2 system expressions alteration can be reversed by taurine, and that taurine can inhibit high glucose-induced RMPs apoptosis via Tie-2.
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136
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Renal ischemia-reperfusion induces release of angiopoietin-2 from human grafts of living and deceased donors. Transplantation 2014; 96:282-9. [PMID: 23839000 DOI: 10.1097/tp.0b013e31829854d5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Recent insights suggest that endothelial cell (EC) activation plays a major role in renal ischemia-reperfusion (I/R) injury. Interactions between ECs and pericytes via signaling molecules, including angiopoietins, are involved in maintenance of the vascular integrity. Experimental data have shown that enhancement of Angiopoietin (Ang)-1 signaling might be beneficial in renal I/R injury. However, little is known about the role of angiopoietins in human renal I/R injury. METHODS In this study, EC activation and changes in angiopoeitins are assessed in human living-donor (LD) and deceased-donor (DD) kidney transplantation. Local release of angiopoietins was measured by unique, dynamic arteriovenous measurements over the reperfused kidney. RESULTS Renal I/R is associated with acute EC activation shown by a vast Ang-2 release from both LD and DD shortly after reperfusion. Its counterpart Ang-1 was not released. Histologic analysis of kidney biopsies showed EC loss after reperfusion. Baseline protein and mRNA Ang-1 expression was significantly reduced in DD compared with LD and declined further after reperfusion. CONCLUSIONS Human renal I/R injury induces EC activation after reperfusion reflected by Ang-2 release from the kidney. Interventions aimed at maintenance of vascular integrity by modulating angiopoietin signaling may be promising in human clinical kidney transplantation.
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137
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Mysona BA, Shanab AY, Elshaer SL, El-Remessy AB. Nerve growth factor in diabetic retinopathy: beyond neurons. EXPERT REVIEW OF OPHTHALMOLOGY 2014; 9:99-107. [PMID: 25031607 PMCID: PMC4096131 DOI: 10.1586/17469899.2014.903157] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Diabetic retinopathy (DR), a major ocular complication of diabetes, is a leading cause of blindness in US working age adults with limited treatments. Neurotrophins (NTs), a family of proteins essential for growth, differentiation and survival of retinal neurons, have emerged as potential players in the pathogenesis of DR. NTs can signal through their corresponding tropomyosin kinase related receptor to mediate cell survival or through the p75 neurotrophin receptor with the co-receptor, sortilin, to mediate cell death. This review focuses on the role of NGF, the first discovered NT, in the development of DR. Impaired processing of proNGF has been found in ocular fluids from diabetic patients as well as experimental models. Evidence from literature and our studies support the notion that NTs appear to play multiple potential roles in DR, hence, understanding their contribution to DR may lead to promising therapeutic approaches for this devastating disease.
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Affiliation(s)
- Barbara A Mysona
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, USA and Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA and Charlie Norwood Veterans Affairs Medical Center, Augusta, GA, USA
| | - Ahmed Y Shanab
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, USA and Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA and Charlie Norwood Veterans Affairs Medical Center, Augusta, GA, USA
| | - Sally L Elshaer
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, USA and Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA and Charlie Norwood Veterans Affairs Medical Center, Augusta, GA, USA
| | - Azza B El-Remessy
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, USA and Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA and Charlie Norwood Veterans Affairs Medical Center, Augusta, GA, USA
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Geevarghese A, Herman IM. Pericyte-endothelial crosstalk: implications and opportunities for advanced cellular therapies. Transl Res 2014; 163:296-306. [PMID: 24530608 PMCID: PMC3976718 DOI: 10.1016/j.trsl.2014.01.011] [Citation(s) in RCA: 161] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 01/15/2014] [Accepted: 01/17/2014] [Indexed: 12/13/2022]
Abstract
Pericytes are mural cells of the microcirculation that have been shown to play key roles in regulating microvascular morphogenesis and stability throughout each tissue bed and organ system assessed. Of note, recent work has revealed that pericytes share several characteristics with mesenchymal- and adipose-derived stem cells, suggesting there may be lineage-related connections among bona fide pericytes and these vascular "progenitors," which can assume a perivascular position in association with endothelial cells. Hence, pericyte identity as a mediator of vascular remodeling may be confounded by its close relationships with its progenitors or pluripotent cell counterparts and yet demonstrates their potential utility as cell-based therapies for unmet clinical needs. Crucial to the development of such therapies is a comprehensive understanding of the origin and fate regulating these related cell types as well as the unveiling of the molecular mechanisms by which pericytes and endothelial cells communicate. Such mechanistic inputs, which disrupt normal cellular crosstalk during disease inception and progression, offer opportunities for intervention and are discussed in the context of the vasculopathies accompanying tumor growth, diabetes, and fibrosis.
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Affiliation(s)
- Anita Geevarghese
- Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Center for Innovations in Wound Healing Research, Tufts University School of Medicine, Boston, Mass
| | - Ira M Herman
- Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Center for Innovations in Wound Healing Research, Tufts University School of Medicine, Boston, Mass.
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Buga AM, Margaritescu C, Scholz CJ, Radu E, Zelenak C, Popa-Wagner A. Transcriptomics of post-stroke angiogenesis in the aged brain. Front Aging Neurosci 2014; 6:44. [PMID: 24672479 PMCID: PMC3957426 DOI: 10.3389/fnagi.2014.00044] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 02/27/2014] [Indexed: 12/27/2022] Open
Abstract
Despite the obvious clinical significance of post-stroke angiogenesis in aged subjects, a detailed transcriptomic analysis of post-stroke angiogenesis has not yet been undertaken in an aged experimental model. In this study, by combining stroke transcriptomics with immunohistochemistry in aged rats and post-stroke patients, we sought to identify an age-specific gene expression pattern that may characterize the angiogenic process after stroke. We found that both young and old infarcted rats initiated vigorous angiogenesis. However, the young rats had a higher vascular density by day 14 post-stroke. “New-for-stroke” genes that were linked to the increased vasculature density in young animals included Angpt2, Angptl2, Angptl4, Cib1, Ccr2, Col4a2, Cxcl1, Lef1, Hhex, Lamc1, Nid2, Pcam1, Plod2, Runx3, Scpep1, S100a4, Tgfbi, and Wnt4, which are required for sprouting angiogenesis, reconstruction of the basal lamina (BL), and the resolution phase. The vast majority of genes involved in sprouting angiogenesis (Angpt2, Angptl4, Cib1, Col8a1, Nrp1, Pcam1, Pttg1ip, Rac2, Runx1, Tnp4, Wnt4); reconstruction of a new BL (Col4a2, Lamc1, Plod2); or tube formation and maturation (Angpt1, Gpc3, Igfbp7, Sparc, Tie2, Tnfsf10), had however, a delayed upregulation in the aged rats. The angiogenic response in aged rats was further diminished by the persistent upregulation of “inflammatory” genes (Cxcl12, Mmp8, Mmp12, Mmp14, Mpeg1, Tnfrsf1a, Tnfrsf1b) and vigorous expression of genes required for the buildup of the fibrotic scar (Cthrc1, Il6ra, Il13ar1, Il18, Mmp2, Rassf4, Tgfb1, Tgfbr2, Timp1). Beyond this barrier, angiogenesis in the aged brains was similar to that in young brains. We also found that the aged human brain is capable of mounting a vigorous angiogenic response after stroke, which most likely reflects the remaining brain plasticity of the aged brain.
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Affiliation(s)
- Ana Maria Buga
- Department of Psychiatry, University of Medicine Rostock , Rostock , Germany ; Center of Clinical and Experimental Medicine, University of Medicine Craiova , Craiova , Romania
| | - Claudiu Margaritescu
- Center of Clinical and Experimental Medicine, University of Medicine Craiova , Craiova , Romania
| | - Claus Juergen Scholz
- IZKF Lab for Microarray Applications, University of Würzburg , Würzburg , Germany
| | - Eugen Radu
- University of Medicine and Pharmacy Carol Davila , Bucharest , Romania
| | - Christine Zelenak
- Molecular Oncology, Department of Medicine, Lady Davis Institute for Medical Research, McGill University , Montreal, QC , Canada
| | - Aurel Popa-Wagner
- Department of Psychiatry, University of Medicine Rostock , Rostock , Germany
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140
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Chowdhury HR, Patel N, Sivaprasad S. Ocular neovascularization: potential for the angiopoietin/Tie-2 pathway. EXPERT REVIEW OF OPHTHALMOLOGY 2014. [DOI: 10.1586/17469899.4.1.65] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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141
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Schallek J, Geng Y, Nguyen H, Williams DR. Morphology and topography of retinal pericytes in the living mouse retina using in vivo adaptive optics imaging and ex vivo characterization. Invest Ophthalmol Vis Sci 2013; 54:8237-50. [PMID: 24150762 DOI: 10.1167/iovs.13-12581] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE To noninvasively image retinal pericytes in the living eye and characterize NG2-positive cell topography and morphology in the adult mouse retina. METHODS Transgenic mice expressing fluorescent pericytes (NG2, DsRed) were imaged using a two-channel, adaptive optics scanning laser ophthalmoscope (AOSLO). One channel imaged vascular perfusion with near infrared light. A second channel simultaneously imaged fluorescent retinal pericytes. Mice were also imaged using wide-field ophthalmoscopy. To confirm in vivo imaging, five eyes were enucleated and imaged in flat mount with conventional fluorescent microscopy. Cell topography was quantified relative to the optic disc. RESULTS We observed strong DsRed fluorescence from NG2-positive cells. AOSLO revealed fluorescent vascular mural cells enveloping all vessels in the living retina. Cells were stellate on larger venules, and showed banded morphology on arterioles. NG2-positive cells indicative of pericytes were found on the smallest capillaries of the retinal circulation. Wide-field SLO enabled quick assessment of NG2-positive distribution, but provided insufficient resolution for cell counts. Ex vivo microscopy showed relatively even topography of NG2-positive capillary pericytes at eccentricities more than 0.3 mm from the optic disc (515 ± 94 cells/mm(2) of retinal area). CONCLUSIONS We provide the first high-resolution images of retinal pericytes in the living animal. Subcellular resolution enabled morphological identification of NG2-positive cells on capillaries showing classic features and topography of retinal pericytes. This report provides foundational basis for future studies that will track and quantify pericyte topography, morphology, and function in the living retina over time, especially in the progression of microvascular disease.
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Affiliation(s)
- Jesse Schallek
- Center for Visual Science, University of Rochester, Rochester, New York
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142
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Liu J, Wang Y, Akamatsu Y, Lee CC, Stetler RA, Lawton MT, Yang GY. Vascular remodeling after ischemic stroke: mechanisms and therapeutic potentials. Prog Neurobiol 2013; 115:138-56. [PMID: 24291532 DOI: 10.1016/j.pneurobio.2013.11.004] [Citation(s) in RCA: 251] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Revised: 11/14/2013] [Accepted: 11/16/2013] [Indexed: 12/18/2022]
Abstract
The brain vasculature has been increasingly recognized as a key player that directs brain development, regulates homeostasis, and contributes to pathological processes. Following ischemic stroke, the reduction of blood flow elicits a cascade of changes and leads to vascular remodeling. However, the temporal profile of vascular changes after stroke is not well understood. Growing evidence suggests that the early phase of cerebral blood volume (CBV) increase is likely due to the improvement in collateral flow, also known as arteriogenesis, whereas the late phase of CBV increase is attributed to the surge of angiogenesis. Arteriogenesis is triggered by shear fluid stress followed by activation of endothelium and inflammatory processes, while angiogenesis induces a number of pro-angiogenic factors and circulating endothelial progenitor cells (EPCs). The status of collaterals in acute stroke has been shown to have several prognostic implications, while the causal relationship between angiogenesis and improved functional recovery has yet to be established in patients. A number of interventions aimed at enhancing cerebral blood flow including increasing collateral recruitment are under clinical investigation. Transplantation of EPCs to improve angiogenesis is also underway. Knowledge in the underlying physiological mechanisms for improved arteriogenesis and angiogenesis shall lead to more effective therapies for ischemic stroke.
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Affiliation(s)
- Jialing Liu
- Department of Neurological Surgery, UCSF, San Francisco, CA 94121, USA; SFVAMC, San Francisco, CA 94121, USA.
| | - Yongting Wang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute, Shanghai 200030, China; School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China; Department of Neurology, Shanghai Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China
| | - Yosuke Akamatsu
- Department of Neurological Surgery, UCSF, San Francisco, CA 94121, USA; SFVAMC, San Francisco, CA 94121, USA; Department of Neurological Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Chih Cheng Lee
- Department of Neurological Surgery, UCSF, San Francisco, CA 94121, USA; SFVAMC, San Francisco, CA 94121, USA
| | - R Anne Stetler
- Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Michael T Lawton
- Department of Neurological Surgery, UCSF, San Francisco, CA 94121, USA
| | - Guo-Yuan Yang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute, Shanghai 200030, China; School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China; Department of Neurology, Shanghai Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China.
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143
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Van Geest RJ, Leeuwis JW, Dendooven A, Pfister F, Bosch K, Hoeben KA, Vogels IMC, Van der Giezen DM, Dietrich N, Hammes HP, Goldschmeding R, Klaassen I, Van Noorden CJF, Schlingemann RO. Connective tissue growth factor is involved in structural retinal vascular changes in long-term experimental diabetes. J Histochem Cytochem 2013; 62:109-18. [PMID: 24217924 PMCID: PMC3902096 DOI: 10.1369/0022155413512656] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Early retinal vascular changes in the development of diabetic retinopathy (DR) include capillary basal lamina (BL) thickening, pericyte loss and the development of acellular capillaries. Expression of the CCN (connective tissue growth factor/cysteine-rich 61/nephroblastoma overexpressed) family member CCN2 or connective tissue growth factor (CTGF), a potent inducer of the expression of BL components, is upregulated early in diabetes. Diabetic mice lacking one functional CTGF allele (CTGF⁺/⁻) do not show this BL thickening. As early events in DR may be interrelated, we hypothesized that CTGF plays a role in the pathological changes of retinal capillaries other than BL thickening. We studied the effects of long-term (6-8 months) streptozotocin-induced diabetes on retinal capillary BL thickness, numbers of pericytes and the development of acellular capillaries in wild type and CTGF⁺/⁻ mice. Our results show that an absence of BL thickening of retinal capillaries in long-term diabetic CTGF⁺/⁻ mice is associated with reduced pericyte dropout and reduced formation of acellular capillaries. We conclude that CTGF is involved in structural retinal vascular changes in diabetic rodents. Inhibition of CTGF in the eye may therefore be protective against the development of DR.
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Affiliation(s)
- Rob J Van Geest
- Ocular Angiogenesis Group, Departments of Ophthalmology and Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (RJVG, IMCV, IK, CJFVN, ROS)
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144
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Negrão R, Duarte D, Costa R, Soares R. Isoxanthohumol modulates angiogenesis and inflammation via vascular endothelial growth factor receptor, tumor necrosis factor alpha and nuclear factor kappa B pathways. Biofactors 2013; 39:608-22. [PMID: 23904052 DOI: 10.1002/biof.1122] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 05/02/2013] [Accepted: 05/20/2013] [Indexed: 12/12/2022]
Abstract
Angiogenesis and inflammation are becoming distinguished players in the pathogenesis of many heterogeneous diseases, such as diabetes, cardiovascular disease, and cancer. Therefore, it is crucial to study new compounds that are able to modulate these events. Isoxanthohumol (IXN) is a polyphenol with antioxidant, anti-inflammatory, and antiangiogenic properties. The aim of this study was to evaluate the effects of IXN on blood vessel proliferation and maturation and describe underlying molecular mechanisms in endothelial cells (ECs) and vascular smooth muscle cells (VSMCs). Angiogenic profile of IXN was analyzed by retinal angiogenesis at different time points. IXN modulation of angiogenic and inflammatory signaling pathways was evaluated by Western blotting on EC and VSMC cultures. IXN inhibited by 20% sprouting angiogenesis and decreased vascular coverage by mural cells up to 39%. IXN of 10 µM also decreased inflammatory signals, namely tumor necrosis factor alpha (TNF-α) (26 and 40%) and factor nuclear kappa B (24 and 42%) in human aortic smooth muscle cells (HASMCs) and human umbilical vein endothelial cells (HUVECs). Angiogenic regulators, including vascular endothelial growth factor receptor 2 (HUVEC, 55%), angiopoietins 1 (HUVEC, 39%; HASMC, 35%), angiopoietin 2 (HUVEC, 38%), and Tie2 (HUVEC, 56%) were also inhibited by 10 µM of IXN treatments. Akt activation was reduced by 47% in HUVEC-treated cells and Erk activation was also reduced by 52 and 69% upon IXN treatment of HUVEC and HASMC. IXN seems to regulate in vivo vascular proliferation and stabilization and the EC-VSMC-inflammatory crosstalk, leaving this molecule as an interesting nutritional player for angiogenesis and inflammation-related diseases.
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Affiliation(s)
- Rita Negrão
- Department of Biochemistry (U38-FCT), Faculty of Medicine, University of Porto, Porto, Portugal
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145
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Protective effects of fufang xueshuantong on diabetic retinopathy in rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:408268. [PMID: 24204392 PMCID: PMC3800603 DOI: 10.1155/2013/408268] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 08/20/2013] [Indexed: 11/18/2022]
Abstract
The aim of this study was to evaluate the protective effects of Fufang Xueshuantong (FXT) on diabetic retinopathy in rats induced by streptozotocin (STZ). Diabetes was induced in Sprague-Dawley rats by a single injection of 60 mg/kg STZ. One week after STZ, FXT 0.525 g/kg or 1.05 g/kg was administrated to the rats by intragastric gavage (ig) once daily consecutively for 24 weeks. The control rats and untreated STZ rats received vehicle the same way. At the end of the experiment, the erythrocyte aggregation and blood viscosity were assayed. The retina vessel morphology was observed in retinal digestive preparations. Expression of occludin and intercellular adhesion molecule-1 (ICAM-1) in retina was measured by western blotting. Expression of vascular endothelial growth factor (VEGF) and pigment epithelium derived factor (PEDF) in retina was detected by immunohistochemistry. The activity of aldose reductase in retina was investigated with a NADPH oxidation method. The results showed that, in STZ rats, there were distinct lesions in retinal vessel, including decrease of pericytes and increase of acellular capillaries, together with dilatation of retinal veins. The expression of VEGF and ICAM-1 increased, while the expression of PEDF and occludin decreased. The activity of aldose reductase elevated, and the whole blood viscosity, plasma viscosity, and erythrocyte aggregation also increased after STZ stimulation. FXT 0.525 g/kg and 1.05 g/kg demonstrated significant protective effects against STZ induced microvessel lesion in the retina with increased pericytes and reduced acellular capillaries. FXT also reduced the expression of VEGF and ICAM-1 and enhanced the expression of PEDF and occludin in STZ insulted rats. The activity of aldose reductase, the whole blood viscosity, plasma viscosity, and erythrocyte aggregation also decreased after FXT treatment. The results demonstrated that FXT has protective effect on STZ induced diabetic retinopathy in rats.
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146
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Wanjare M, Kusuma S, Gerecht S. Perivascular cells in blood vessel regeneration. Biotechnol J 2013; 8:434-47. [PMID: 23554249 DOI: 10.1002/biot.201200199] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 02/19/2013] [Accepted: 03/05/2013] [Indexed: 12/21/2022]
Abstract
Vascular engineering seeks to design and construct functional blood vessels comprising endothelial cells (ECs) and perivascular cells (PCs), with the ultimate goal of clinical translation. While EC behavior has been extensively investigated, PCs play an equally significant role in the development of novel regenerative strategies, providing functionality and stability to vessels. The two major classes of PCs are vascular smooth muscle cells (vSMCs) and pericytes; vSMCs can be further sub-classified as either contractile or synthetic. The inclusion of these cell types is crucial for successful regeneration of blood vessels. Furthermore, understanding distinctions between vSMCs and pericytes will enable improved therapeutics in a tissue-specific manner. Here we focus on the approaches and challenges facing the use of PCs in vascular regeneration, including their characteristics, stem cell sources, and interactions with ECs. Finally, we discuss biochemical and microRNA (miR) regulators of PC behavior and engineering approaches that mimic various cues affecting PC function.
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Affiliation(s)
- Maureen Wanjare
- Department of Chemical and Biomolecular Engineering, Johns Hopkins Physical Sciences-Oncology Center and Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, MD 21218, USA
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147
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Chang WG, Andrejecsk JW, Kluger MS, Saltzman WM, Pober JS. Pericytes modulate endothelial sprouting. Cardiovasc Res 2013; 100:492-500. [PMID: 24042014 DOI: 10.1093/cvr/cvt215] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
AIM Angiogenic sprouts arise from microvessels formed by endothelial cells (ECs) invested by pericytes (PCs). The aim of this study was to examine the role of PCs in angiogenic sprouting, an understudied phenomenon. METHODS AND RESULTS We adapted a human EC spheroid model to examine PC effects on vascular endothelial growth factor-A-induced EC sprouting in vitro by using Bcl-2-transduced human umbilical vein ECs to reduce apoptosis in collagen gels. Human placental PCs, separated from endothelial spheroids by a transwell, or addition of PC-conditioned media increased EC sprouting primarily through hepatocyte growth factor (HGF). Mixed endothelial-PC spheroids formed similar numbers of endothelial sprouts as endothelial spheroids but the sprouts from mixed spheroids were invested by PCs within 24 h. PCs were recruited to the sprouts by platelet-derived growth factor (PDGF)-BB; inhibition of PDGF signalling reduced PC coverage and increased EC sprouting. Transplanted endothelial spheroids give rise to sprouts in vivo that evolve into perfused microvessels. Mixed endothelial-PC spheroids form similar numbers of microvessels as endothelial-only spheroids, but acquire human PC investment and have reduced average lumen diameter. CONCLUSIONS PCs promote endothelial sprouting by elaborating HGF, but when recruited to invest endothelial sprouts by PDGF-BB, limit the extent of sprouting in vitro and lumen diameter in vivo.
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Affiliation(s)
- William G Chang
- Department of Medicine and Section of Nephrology, Yale University School of Medicine, New Haven, CT 06520, USA
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148
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Jeltsch M, Leppänen VM, Saharinen P, Alitalo K. Receptor tyrosine kinase-mediated angiogenesis. Cold Spring Harb Perspect Biol 2013; 5:5/9/a009183. [PMID: 24003209 DOI: 10.1101/cshperspect.a009183] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The endothelial cell is the essential cell type forming the inner layer of the vasculature. Two families of receptor tyrosine kinases (RTKs) are almost completely endothelial cell specific: the vascular endothelial growth factor (VEGF) receptors (VEGFR1-3) and the Tie receptors (Tie1 and Tie2). Both are key players governing the generation of blood and lymphatic vessels during embryonic development. Because the growth of new blood and lymphatic vessels (or the lack thereof) is a central element in many diseases, the VEGF and the Tie receptors provide attractive therapeutic targets in various diseases. Indeed, several drugs directed to these RTK signaling pathways are already on the market, whereas many are in clinical trials. Here we review the VEGFR and Tie families, their involvement in developmental and pathological angiogenesis, and the different possibilities for targeting them to either block or enhance angiogenesis and lymphangiogenesis.
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Affiliation(s)
- Michael Jeltsch
- Wihuri Research Institute, Biomedicum Helsinki, University of Helsinki, FIN-00014 Helsinki, Finland
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149
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The angiopoietin:Tie 2 interaction: a potential target for future therapies in human vascular disease. Cytokine Growth Factor Rev 2013; 24:579-92. [PMID: 23838360 DOI: 10.1016/j.cytogfr.2013.05.009] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Revised: 05/22/2013] [Accepted: 05/24/2013] [Indexed: 01/06/2023]
Abstract
Angiopoietin-1 and -2 are endogenous ligands for the vascular endothelial receptor tyrosine kinase Tie2. Signalling by angiopoietin-1 promotes vascular endothelial cell survival and the sprouting and reorganisation of blood vessels, as well as inhibiting activation of the vascular endothelial barrier to reduce leakage and leucocyte migration into tissues. Angiopoietin-2 generally has an opposing action, and is released naturally at times of vascular growth and inflammation. There is a significant body of emerging evidence that promoting the actions of angiopoietin-1 through Tie2 is of benefit in pathologies of vascular activation, such as sepsis, stroke, diabetic retinopathy and asthma. Similarly, methods to inhibit the actions of angiopoietin-2 are emerging and have been demonstrated to be of preclinical and clinical benefit in reducing tumour angiogenesis. Here the author reviews the evidence for potential benefits of modulation of the interaction of angiopoietins with Tie2, and the potential applications. Additionally, methods for delivery of the complex protein angiopoietin-1 are discussed, as well as potentially deleterious consequences of administering angiopoietin-1.
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150
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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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