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Kam CY, Singh ID, Gonzalez DG, Matte-Martone C, Solá P, Solanas G, Bonjoch J, Marsh E, Hirschi KK, Greco V. Mechanisms of skin vascular maturation and maintenance captured by longitudinal imaging of live mice. Cell 2023; 186:2345-2360.e16. [PMID: 37167971 DOI: 10.1016/j.cell.2023.04.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/03/2023] [Accepted: 04/11/2023] [Indexed: 05/13/2023]
Abstract
A functional network of blood vessels is essential for organ growth and homeostasis, yet how the vasculature matures and maintains homeostasis remains elusive in live mice. By longitudinally tracking the same neonatal endothelial cells (ECs) over days to weeks, we found that capillary plexus expansion is driven by vessel regression to optimize network perfusion. Neonatal ECs rearrange positions to evenly distribute throughout the developing plexus and become positionally stable in adulthood. Upon local ablation, adult ECs survive through a plasmalemmal self-repair response, while neonatal ECs are predisposed to die. Furthermore, adult ECs reactivate migration to assist vessel repair. Global ablation reveals coordinated maintenance of the adult vascular architecture that allows for eventual network recovery. Lastly, neonatal remodeling and adult maintenance of the skin vascular plexus are orchestrated by temporally restricted, neonatal VEGFR2 signaling. Our work sheds light on fundamental mechanisms that underlie both vascular maturation and adult homeostasis in vivo.
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Affiliation(s)
- Chen Yuan Kam
- Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA
| | - Ishani D Singh
- Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA
| | - David G Gonzalez
- Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA
| | | | - Paloma Solá
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
| | - Guiomar Solanas
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
| | - Júlia Bonjoch
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
| | - Edward Marsh
- Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA
| | - Karen K Hirschi
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
| | - Valentina Greco
- Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA; Departments of Cell Biology and Dermatology, Yale Stem Cell Center, Yale Cancer Center, Yale School of Medicine, New Haven, CT 06510, USA.
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Felici A, Bottaro DP, Mangoni A, Reusch P, Marmé D, Kovesdi I, De Silva DM, Lee YH, Capogrossi MC, Mühlhauser J. Regression of Human Breast Carcinoma in Nude Mice after Adsflt Gene Therapy Is Mediated by Tumor Vascular Endothelial Cell Apoptosis. Cancers (Basel) 2022; 14. [PMID: 36551660 DOI: 10.3390/cancers14246175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/25/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022] Open
Abstract
Two vascular endothelial growth factor (VEGF) receptors, FLT-1 and KDR, are expressed preferentially in proliferating endothelium. There is increasing evidence that recombinant, soluble VEGF receptor domains interfering with VEGF signaling may inhibit in vivo neoangiogenesis, tumor growth and metastatic spread. We hypothesized that a soluble form of FLT-1 receptor (sFLT-1) could inhibit the growth of pre-established tumors via an anti-angiogenic mechanism. A replication-deficient adenovirus (Ad) vector carrying the sflt-1 cDNA (Adsflt) was used to overexpress the sFLT-1 receptor in a breast cancer animal model. MCF-7 cells, which produce VEGF, were used to establish solid tumors in the mammary fat pads of female nude mice. After six weeks, tumors were injected either with Adsflt or a negative control virus (AdCMV.βgal). After six months, average tumor volume in the Adsflt-infected group (33 ± 22 mm3) decreased by 91% relative to that of the negative control group (388 ± 94 mm3; p < 0.05). Moreover, 10 of 15 Adsflt-infected tumors exhibited complete regression. The vascular density of Adsflt-infected tumors was reduced by 50% relative to that of negative controls (p < 0.05), which is consistent with sFLT-1-mediated tumor regression through an anti-angiogenic mechanism. Moreover, cell necrosis and fibrosis associated with long-term regression of Adsflt−infected tumors were preceded by apoptosis of tumor vascular endothelial cells. Mice treated with Adsflt intratumorally showed no delay in the healing of cutaneous wounds, providing preliminary evidence that Ad-mediated sFLT-1 overexpression may be an effective anti-angiogenic therapy for cancer without the risk of systemic anti-angiogenic effects.
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Benn A, Alonso F, Mangelschots J, Génot E, Lox M, Zwijsen A. BMP-SMAD1/5 Signaling Regulates Retinal Vascular Development. Biomolecules 2020; 10:E488. [PMID: 32210087 DOI: 10.3390/biom10030488] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/16/2020] [Accepted: 03/18/2020] [Indexed: 12/15/2022] Open
Abstract
Vascular development is an orchestrated process of vessel formation from pre-existing vessels via sprouting and intussusceptive angiogenesis as well as vascular remodeling to generate the mature vasculature. Bone morphogenetic protein (BMP) signaling via intracellular SMAD1 and SMAD5 effectors regulates sprouting angiogenesis in the early mouse embryo, but its role in other processes of vascular development and in other vascular beds remains incompletely understood. Here, we investigate the function of SMAD1/5 during early postnatal retinal vascular development using inducible, endothelium-specific deletion of Smad1 and Smad5. We observe the formation of arterial-venous malformations in areas with high blood flow, and fewer and less functional tip cells at the angiogenic front. The vascular plexus region is remarkably hyperdense and this is associated with reduced vessel regression and aberrant vascular loop formation. Taken together, our results highlight important functions of SMAD1/5 during vessel formation and remodeling in the early postnatal retina.
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Michalczyk ER, Chen L, Maia MB, DiPietro LA. A Role for Low-Density Lipoprotein Receptor-Related Protein 6 in Blood Vessel Regression in Wound Healing. Adv Wound Care (New Rochelle) 2020; 9:1-8. [PMID: 31871825 PMCID: PMC6918844 DOI: 10.1089/wound.2019.1019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 10/25/2019] [Indexed: 01/22/2023] Open
Abstract
Objective: The healing of skin wounds is typified by a pattern of robust angiogenesis followed by vascular regression. Pigment epithelium-derived factor (PEDF), a recognized endogenous antiangiogenic protein, regulates vascular regression in resolving wounds through an unknown receptor. Among the multiple receptors for PEDF that have been identified, low-density lipoprotein receptor-related protein 6 (Lrp6) has been described as a regulator of angiogenesis in multiple systems. The purpose of the current study was to determine if the Lrp6 receptor plays a role in vessel regression in wounds. Approach: Excisional skin wounds were prepared on C57BL/6 mice. RT-PCR and immunoblots were performed to measure Lrp6 expression over a time course of wound healing. Immunohistochemistry was performed to localize Lrp6 in both recombinant PEDF (rPEDF)-treated and control wounds. To examine whether Lrp6 is critical to the regulation of capillary regression in vivo, wounds were treated with Lrp6 siRNA to minimize its presence in wounds. Immunohistochemistry for CD31 was performed to quantify blood vessel density. Results: PCR and immunoblots revealed significant increases in Lrp6 expression during the vascular regression phase of wound healing. Lrp6 was found to colocalize with CD31+ endothelial cells in wounds. The addition of rPEDF to wounds caused an increase in Lrp6-CD31+ endothelial cell colocalization. Inhibition of Lrp6 by siRNA impeded the vascular regression phase of healing. Innovation: This study is the first to demonstrate an association between Lrp6 and vessel regression in wound healing. Conclusion: Lrp6 is expressed in wounds in a temporal and spatial manner that suggests it may be a receptor for PEDF during vascular regression. PEDF increases Lrp6 expression in the wound vasculature, and inhibition of Lrp6 blocked vascular regression in wounds. The results suggest that Lrp6 is important to vascular regression in wounds, possibly through direct interaction with PEDF.
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Affiliation(s)
- Elizabeth R. Michalczyk
- Center for Wound Healing and Tissue Regeneration, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois
| | - Lin Chen
- Center for Wound Healing and Tissue Regeneration, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois
| | - Mariana B. Maia
- Center for Wound Healing and Tissue Regeneration, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois
| | - Luisa A. DiPietro
- Center for Wound Healing and Tissue Regeneration, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois
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Yang J, Zhang G, Li Q, Liao C, Huang L, Ke T, Jiang H, Han D. Photoacoustic imaging for the evaluation of early tumor response to antivascular treatment. Quant Imaging Med Surg 2019; 9:160-170. [PMID: 30976540 DOI: 10.21037/qims.2018.11.06] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Background Photoacoustic imaging (PAI) provides real-time noninvasive and contrast agent-free monitoring of the concentrations of some endogenous compounds related to tumor vascularization and oxygenation. In this study, we used PAI to noninvasively evaluate tumor responses to antiangiogenic therapy. Methods In vivo studies were performed with the approval of our institutional animal ethics committee. We used a xenograft mouse model of 4T1 breast cancer treated with different doses of bevacizumab or vehicle. Seven days after implantation, tumor-bearing mice (with tumors ~5-8 mm diameter) were randomly divided into low-dose (10 mg/kg), high-dose (20 mg/kg) and vehicle groups (same dose of saline). Each experimental group was administered bevacizumab intraperitoneally only once. Before and after treatment, acoustic resolution-photoacoustic microscopy (AR-PAM), a type of PAI, was conducted in vivo consecutively from day 1 to day 5. PAI-derived quantitative parameters were calculated at each time point. Additional cohorts of mice were used to quantify CD31 and hypoxia by immunohistochemical assays. Results The values of the PAI parameters were not significantly different among the experimental and control groups at the same time point before treatment (all P>0.05). The total hemoglobin (HbT) levels in the treatment group gradually decreased from day 1 to day 2 (relative to those in the control group, P>0.05) and decreased significantly relative to those in the control group from day 3 to day 5 (P<0.05). The deoxyhemoglobin (HbR) levels in the treatment group decreased from day 1 to 5 after treatment. The high-dose group had significantly decreased HbR levels relative to the control group from day 1 to 5 (P<0.05). The low-dose group also showed a gradual and significant decrease in HbR levels on day 3 (P<0.05). CD31 was decreased in the low-dose group relative to the control group on day 1 (decreased by 34.05%, P=0.067) and day 3 (decreased by 45.27%, P=0.180), and the decrease in CD31 persisted on day 5 (decreased by 71.41%, P=0.000). CD31 decreased to a greater extent in the high-dose group than in the low-dose group. Tumor hypoxia was significantly increased on day 1 from day 0 in the treatment groups (P<0.05), especially in the high-dose group. Hypoxia was decreased on days 3 and 5 in the low-dose group (10.92±0.92 and 8.17±1.9, P=0.317) but continuously increased over time in the high-dose group. Significantly greater hypoxia was observed in the high-dose group than in the low-dose group (17.60±1.20 and 20.33±0.47, P<0.05). Conclusions PAI can be used to evaluate both vessel regression and hypoxia in response to anti-vascular treatment.
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Affiliation(s)
- Jun Yang
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming 650118, Yunnan, China.,Department of Medical Imaging, The First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
| | - Guang Zhang
- School of Electronic Science and Engineering, University of Electronic Science and Technology, Chengdu 610054, China.,Center for Information in Biomedicine, University of Electronic Science and Technology, Chengdu 610054, China
| | - Qinqing Li
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming 650118, Yunnan, China
| | - Chengde Liao
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming 650118, Yunnan, China
| | - Lin Huang
- School of Electronic Science and Engineering, University of Electronic Science and Technology, Chengdu 610054, China.,Center for Information in Biomedicine, University of Electronic Science and Technology, Chengdu 610054, China
| | - Tengfei Ke
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming 650118, Yunnan, China
| | - Huabei Jiang
- School of Electronic Science and Engineering, University of Electronic Science and Technology, Chengdu 610054, China.,Center for Information in Biomedicine, University of Electronic Science and Technology, Chengdu 610054, China.,Department of Medical Engineering, University of South Florida, Tampa, FL 33620, USA
| | - Dan Han
- Department of Medical Imaging, The First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
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Affiliation(s)
- Silvia Della Bella
- Unit of Clinical and Experimental Immunology, Humanitas Clinical and Research Center, Rozzano, Milan, Italy; and Department of Medical Biotechnologies and Translational Medicine, University of Milan, Italy
| | - Domenico Mavilio
- Unit of Clinical and Experimental Immunology, Humanitas Clinical and Research Center, Rozzano, Milan, Italy; and Department of Medical Biotechnologies and Translational Medicine, University of Milan, Italy
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Franco CA, Jones ML, Bernabeu MO, Vion AC, Barbacena P, Fan J, Mathivet T, Fonseca CG, Ragab A, Yamaguchi TP, Coveney PV, Lang RA, Gerhardt H. Non-canonical Wnt signalling modulates the endothelial shear stress flow sensor in vascular remodelling. eLife 2016; 5:e07727. [PMID: 26845523 PMCID: PMC4798962 DOI: 10.7554/elife.07727] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 02/03/2016] [Indexed: 12/22/2022] Open
Abstract
Endothelial cells respond to molecular and physical forces in development and vascular homeostasis. Deregulation of endothelial responses to flow-induced shear is believed to contribute to many aspects of cardiovascular diseases including atherosclerosis. However, how molecular signals and shear-mediated physical forces integrate to regulate vascular patterning is poorly understood. Here we show that endothelial non-canonical Wnt signalling regulates endothelial sensitivity to shear forces. Loss of Wnt5a/Wnt11 renders endothelial cells more sensitive to shear, resulting in axial polarization and migration against flow at lower shear levels. Integration of flow modelling and polarity analysis in entire vascular networks demonstrates that polarization against flow is achieved differentially in artery, vein, capillaries and the primitive sprouting front. Collectively our data suggest that non-canonical Wnt signalling stabilizes forming vascular networks by reducing endothelial shear sensitivity, thus keeping vessels open under low flow conditions that prevail in the primitive plexus.
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Affiliation(s)
- Claudio A Franco
- Vascular Biology Laboratory, Lincoln's Inn Laboratories, London Research Institute, The Francis Crick Institute, London, United Kingdom
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, Lisbon, Portugal
| | - Martin L Jones
- Vascular Biology Laboratory, Lincoln's Inn Laboratories, London Research Institute, The Francis Crick Institute, London, United Kingdom
| | - Miguel O Bernabeu
- Centre for Medical Informatics, Usher Institute, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Computational Science, Department of Chemistry, University College London, London, United Kingdom
| | - Anne-Clemence Vion
- Vascular Biology Laboratory, Lincoln's Inn Laboratories, London Research Institute, The Francis Crick Institute, London, United Kingdom
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Pedro Barbacena
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, Lisbon, Portugal
| | - Jieqing Fan
- The Visual Systems Group, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, United States
| | - Thomas Mathivet
- Vascular Patterning Laboratory, Vesalius Research Center, Leuven, Belgium
- Department of Oncology, Vascular Patterning Laboratory, Vesalius Research Center, Leuven, Belgium
| | - Catarina G Fonseca
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, Lisbon, Portugal
| | - Anan Ragab
- Vascular Biology Laboratory, Lincoln's Inn Laboratories, London Research Institute, The Francis Crick Institute, London, United Kingdom
| | - Terry P Yamaguchi
- Cancer and Developmental Biology Laboratory, Center for Cancer Research, NCI-Frederick, National Institutes of Health, Frederick, United States
| | - Peter V Coveney
- Centre for Computational Science, Department of Chemistry, University College London, London, United Kingdom
| | - Richard A Lang
- The Visual Systems Group, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, United States
| | - Holger Gerhardt
- Vascular Biology Laboratory, Lincoln's Inn Laboratories, London Research Institute, The Francis Crick Institute, London, United Kingdom
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
- Vascular Patterning Laboratory, Vesalius Research Center, Leuven, Belgium
- Department of Oncology, Vascular Patterning Laboratory, Vesalius Research Center, Leuven, Belgium
- German Center for Cardiovascular Research, Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
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Wietecha MS, Król MJ, Michalczyk ER, Chen L, Gettins PG, DiPietro LA. Pigment epithelium-derived factor as a multifunctional regulator of wound healing. Am J Physiol Heart Circ Physiol 2015; 309:H812-26. [PMID: 26163443 DOI: 10.1152/ajpheart.00153.2015] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 07/08/2015] [Indexed: 01/12/2023]
Abstract
During dermal wound repair, hypoxia-driven proliferation results in dense but highly permeable, disorganized microvascular networks, similar to those in solid tumors. Concurrently, activated dermal fibroblasts generate an angiopermissive, provisional extracellular matrix (ECM). Unlike cancers, wounds naturally resolve via blood vessel regression and ECM maturation, which are essential for reestablishing tissue homeostasis. Mechanisms guiding wound resolution are poorly understood; one candidate regulator is pigment epithelium-derived factor (PEDF), a secreted glycoprotein. PEDF is a potent antiangiogenic in models of pathological angiogenesis and a promising cancer and cardiovascular disease therapeutic, but little is known about its physiological function. To examine the roles of PEDF in physiological wound repair, we used a reproducible model of excisional skin wound healing in BALB/c mice. We show that PEDF is abundant in unwounded and healing skin, is produced primarily by dermal fibroblasts, binds to resident microvascular endothelial cells, and accumulates in dermal ECM and epidermis. PEDF transcript and protein levels were low during the inflammatory and proliferative phases of healing but increased in quantity and colocalization with microvasculature during wound resolution. Local antibody inhibition of endogenous PEDF delayed vessel regression and collagen maturation during the remodeling phase. Treatment of wounds with intradermal injections of exogenous, recombinant PEDF inhibited nascent angiogenesis by repressing endothelial proliferation, promoted vascular integrity and function, and increased collagen maturity. These results demonstrate that PEDF contributes to the resolution of healing wounds by causing regression of immature blood vessels and stimulating maturation of the vascular microenvironment, thus promoting a return to tissue homeostasis after injury.
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Affiliation(s)
- Mateusz S Wietecha
- Center for Wound Healing and Tissue Regeneration, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois; and
| | - Mateusz J Król
- Center for Wound Healing and Tissue Regeneration, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois; and
| | - Elizabeth R Michalczyk
- Center for Wound Healing and Tissue Regeneration, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois; and
| | - Lin Chen
- Center for Wound Healing and Tissue Regeneration, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois; and
| | - Peter G Gettins
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois
| | - Luisa A DiPietro
- Center for Wound Healing and Tissue Regeneration, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois; and
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Yang Y, Zhang Y, Cao Z, Ji H, Yang X, Iwamoto H, Wahlberg E, Länne T, Sun B, Cao Y. Anti-VEGF- and anti-VEGF receptor-induced vascular alteration in mouse healthy tissues. Proc Natl Acad Sci U S A. 2013;110:12018-12023. [PMID: 23818623 DOI: 10.1073/pnas.1301331110] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Systemic therapy with anti-VEGF drugs such as bevacizumab is widely used for treatment of human patients with various solid tumors. However, systemic impacts of such drugs in host healthy vasculatures remain poorly understood. Here, we show that, in mice, systemic delivery of an anti-VEGF or an anti-VEGF receptor (VEGFR)-2 neutralizing antibody caused global vascular regression. Among all examined tissues, vasculatures in endocrine glands, intestinal villi, and uterus are the most affected in response to VEGF or VEGFR-2 blockades. Thyroid vascular fenestrations were virtually completely blocked by VEGF blockade, leading to marked accumulation of intraendothelial caveolae vesicles. VEGF blockade markedly increased thyroid endothelial cell apoptosis, and withdrawal of anti-VEGF resulted in full recovery of vascular density and architecture after 14 d. Prolonged anti-VEGF treatment resulted in a significant decrease of the circulating level of the predominant thyroid hormone free thyroxine, but not the minimal isoform of triiodothyronine, suggesting that chronic anti-VEGF treatment impairs thyroid functions. Conversely, VEGFR-1-specific blockade produced virtually no obvious phenotypes. These findings provide structural and functional bases of anti-VEGF-specific drug-induced side effects in relation to vascular changes in healthy tissues. Understanding anti-VEGF drug-induced vascular alterations in healthy tissues is crucial to minimize and even to avoid adverse effects produced by currently used anti-VEGF-specific drugs.
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Klueh U, Kaur M, Montrose DC, Kreutzer DL. Inflammation and glucose sensors: use of dexamethasone to extend glucose sensor function and life span in vivo. J Diabetes Sci Technol 2007; 1:496-504. [PMID: 19885112 PMCID: PMC2769643 DOI: 10.1177/193229680700100407] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND It has been generally accepted that the acute loss of sensor function is the consequence of sensor biofouling as a result of inflammation induced at sites of sensor implantation, as well as tissue trauma induced by the sensor and its implantation. Because anti-inflammatory therapies are used routinely to control inflammation in a wide variety of diseases, we hypothesized that anti-inflammatory therapy would likely extend glucose sensor function in vivo. To test this hypothesis, we utilized our recently developed mouse model of implantable glucose sensors and the potent anti-inflammatory steroid dexamethasone (DEX). METHOD For this study, glucose sensors were implanted subcutaneously into the head and neck area of mice and sensor function was determined up to 14 days postimplantation. These mice received a daily intraperitoneal injection of DEX at a dose of 1, 6, or 10 mg/kg body weight. RESULTS Mice not treated with DEX lost sensor functionality very rapidly, usually within the first 24 hours postimplantation. Mice treated with DEX at the various doses had an increased sensor life span of up to 2 weeks postimplantation. Additionally, sensitivity was maintained in DEX-treated mice as compared to control mice (non-DEX treated). Histologic evaluation of tissue surrounding the site of sensor implantation had almost no inflammatory cells in DEX-treated mice, whereas control mice had an intense band of inflammation surrounding the site of sensor implantation. CONCLUSION To our knowledge this is the first study directly demonstrating that anti-inflammatory therapy can extend glucose sensor function in vivo and supports the key role of inflammation in loss of sensor function in vivo, as well as the uses of anti-inflammatory therapy as a potential key adjuvant in enhancing glucose sensor function and life span in vivo.
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Affiliation(s)
- Ulrike Klueh
- Center for Molecular Tissue Engineering and Department of Surgery, University of Connecticut, School of Medicine, Farmington, Connecticut 06030, USA.
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Benjamin LE, Keshet E. Conditional switching of vascular endothelial growth factor (VEGF) expression in tumors: induction of endothelial cell shedding and regression of hemangioblastoma-like vessels by VEGF withdrawal. Proc Natl Acad Sci U S A 1997; 94:8761-6. [PMID: 9238051 PMCID: PMC23118 DOI: 10.1073/pnas.94.16.8761] [Citation(s) in RCA: 370] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We have recently shown that VEGF functions as a survival factor for newly formed vessels during developmental neovascularization, but is not required for maintenance of mature vessels. Reasoning that expanding tumors contain a significant fraction of newly formed and remodeling vessels, we examined whether abrupt withdrawal of VEGF will result in regression of preformed tumor vessels. Using a tetracycline-regulated VEGF expression system in xenografted C6 glioma cells, we showed that shutting off VEGF production leads to detachment of endothelial cells from the walls of preformed vessels and their subsequent death by apoptosis. Vascular collapse then leads to hemorrhages and extensive tumor necrosis. These results suggest that enforced withdrawal of vascular survival factors can be applied to target preformed tumor vasculature in established tumors. The system was also used to examine phenotypes resulting from over-expression of VEGF. When expression of the transfected VEGF cDNA was continuously "on," tumors became hyper-vascularized with abnormally large vessels, presumably arising from excessive fusions. Tumors were significantly less necrotic, suggesting that necrosis in these tumors is the result of insufficient angiogenesis.
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Affiliation(s)
- L E Benjamin
- Department of Molecular Biology, Hadassah Medical School, The Hebrew University, Jerusalem 91120, Israel
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