1
|
Huang HJ, Chang XW, Hsieh CL, Li D, Chen YF. Compact efficient high-power continuous-wave Nd:YVO 4/KGW/LBO Raman lasers for selectable wavelengths within 559-603 nm. OPTICS EXPRESS 2024; 32:14133-14142. [PMID: 38859367 DOI: 10.1364/oe.520582] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/21/2024] [Indexed: 06/12/2024]
Abstract
Compact efficient high-power continuous-wave Nd:YVO4 Raman lasers for selectable wavelengths within 559-603 nm are achieved by using KGW crystal for intracavity stimulated Raman scattering (SRS) and lithium triborate (LBO) crystal for intracavity sum frequency generation (SFG) and second harmonic generation (SHG). The LBO crystal with the cut angle in the XY plane for the type-I phase matching is used to perform intracavity SHG or SFG. Experimental results reveal that the participated Stokes lines include the internal vibration mode at 901 cm-1, the external vibrational mode at 209 cm-1, and the combination mode of the 901 cm-1 and 209 cm-1 Raman shifts. By tuning LBO temperature for attaining the maximum output power, the output spectrum reveals the triple peaks of 588.7, 595.7, and 603.1 nm with the intensity ratio of 10:4:1. Under this circumstance, the output power can reach the highest value of 10.8 W at a pump power of 40 W. Furthermore, the output spectrum can be simply concentrated on the single peaks among 588.7 (orange), 565.7 (yellow), and 559.1 nm (lime) by tuning LBO temperature to fulfill the selection of the critical phase matching. The output powers at a pump power of 40 W can be up to 8.0, 6.1, and 9.8 W for the single-peak emission at 588.7, 565.7, and 559.1 nm, respectively. Finally, a dual-peak emission of 565.7 and 572.3 nm with total output power of 5.2 W can be generated by tuning LBO temperature to match the SFG for 572.3 nm.
Collapse
|
2
|
Schalich KM, Koganti PP, Castillo JM, Reiff OM, Cheong SH, Selvaraj V. The uterine secretory cycle: recurring physiology of endometrial outputs that setup the uterine luminal microenvironment. Physiol Genomics 2024; 56:74-97. [PMID: 37694291 DOI: 10.1152/physiolgenomics.00035.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 09/08/2023] [Accepted: 09/08/2023] [Indexed: 09/12/2023] Open
Abstract
Conserved in female reproduction across all mammalian species is the estrous cycle and its regulation by the hypothalamic-pituitary-gonadal (HPG) axis, a collective of intersected hormonal events that are crucial for ensuring uterine fertility. Nonetheless, knowledge of the direct mediators that synchronously shape the uterine microenvironment for successive yet distinct events, such as the transit of sperm and support for progressive stages of preimplantation embryo development, remain principally deficient. Toward understanding the timed endometrial outputs that permit luminal events as directed by the estrous cycle, we used Bovidae as a model system to uniquely surface sample and study temporal shifts to in vivo endometrial transcripts that encode for proteins destined to be secreted. The results revealed the full quantitative profile of endometrial components that shape the uterine luminal microenvironment at distinct phases of the estrous cycle (estrus, metestrus, diestrus, and proestrus). In interpreting this comprehensive log of stage-specific endometrial secretions, we define the "uterine secretory cycle" and extract a predictive understanding of recurring physiological actions regulated within the uterine lumen in anticipation of sperm and preimplantation embryonic stages. This repetitive microenvironmental preparedness to sequentially provide operative support was a stable intrinsic framework, with only limited responses to sperm or embryos if encountered in the lumen within the cyclic time period. In uncovering the secretory cycle and unraveling realistic biological processes, we present novel foundational knowledge of terminal effectors controlled by the HPG axis to direct a recurring sequence of vital functions within the uterine lumen.NEW & NOTEWORTHY This study unravels the recurring sequence of changes within the uterus that supports vital functions (sperm transit and development of preimplantation embryonic stages) during the reproductive cycle in female Ruminantia. These data present new systems knowledge in uterine reproductive physiology crucial for setting up in vitro biomimicry and artificial environments for assisted reproduction technologies for a range of mammalian species.
Collapse
Affiliation(s)
- Kasey M Schalich
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, United States
| | - Prasanthi P Koganti
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, United States
| | - Juan M Castillo
- Department of Clinical Sciences, Veterinary College, Cornell University, Ithaca, New York, United States
| | - Olivia M Reiff
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, United States
| | - Soon Hon Cheong
- Department of Clinical Sciences, Veterinary College, Cornell University, Ithaca, New York, United States
| | - Vimal Selvaraj
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, United States
| |
Collapse
|
3
|
Ke C, Chen C, Yang M, Chen H, Ke Y, Li L. Inhibition of infantile hemangioma growth and promotion of apoptosis via VEGF/PI3K/Akt axis by 755-nm long-pulse alexandrite laser. Biomed J 2023:100675. [PMID: 37944864 DOI: 10.1016/j.bj.2023.100675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 09/28/2023] [Accepted: 10/26/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND Infantile hemangioma (IH) is a common vascular tumor in female infants, which can lead to aesthetic issues and facial scarring. This study aimed to investigate the inhibitory effects and underlying mechanisms of 755 nm long-pulsed alexandrite laser on IH. METHODS Hemangioma endothelial cells (HemECs) were exposed to 755 nm long-pulsed alexandrite laser to evaluate its impact on cell proliferation and apoptosis. A patient-derived xenograft model was established to assess the inhibitory effects of laser treatment on IH in vivo. RESULTS In vitro, 755 nm long-pulsed alexandrite laser effectively suppressed the proliferation of HemECs and induced cell apoptosis. Laser treatment significantly inhibited the volume and weight of tumors, accompanied by significant downregulation of vascular endothelial growth factor A (VEGFA), vascular endothelial growth factor receptor 2 (VEGFR2), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (Akt) expression levels in both hemangioma cells and tumors. Additionally, laser treatment resulted in the conversion of VEGFA165a to VEGFA165b. TUNEL staining demonstrated increased apoptosis in tumor cells after laser treatment, along with upregulation of cleaved caspase-3 and Bax, and downregulation of Bcl-2. CONCLUSION In addition to the principle of selective photothermal decomposition, modulation of the VEGF/PI3K/Akt axis may serve as a potential mechanism for IH treatment using a long pulse-width 755 nm laser. This sheds valuable light on the molecular mechanisms underlying IH pathogenesis and potential therapeutic targets while providing a theoretical basis for the safe and efficient management of proliferative IH using laser therapy.
Collapse
Affiliation(s)
- Chen Ke
- Plastic Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China
| | - Changhan Chen
- Department of Cosmetology, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine, Wenzhou, Zhejiang, 325000, China; Wenzhou Key Laboratory of Laser Cosmetology, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine, Wenzhou, Zhejiang, 325000, China
| | - Ming Yang
- Department of Cosmetology, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine, Wenzhou, Zhejiang, 325000, China
| | - Hao Chen
- Department of Cosmetology, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine, Wenzhou, Zhejiang, 325000, China
| | - Youhui Ke
- Department of Cosmetology, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine, Wenzhou, Zhejiang, 325000, China; Wenzhou Key Laboratory of Laser Cosmetology, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine, Wenzhou, Zhejiang, 325000, China.
| | - Liqun Li
- Plastic Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China.
| |
Collapse
|
4
|
Moon BH, Kim Y, Kim SY. Twenty Years of Anti-Vascular Endothelial Growth Factor Therapeutics in Neovascular Age-Related Macular Degeneration Treatment. Int J Mol Sci 2023; 24:13004. [PMID: 37629185 PMCID: PMC10454953 DOI: 10.3390/ijms241613004] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/10/2023] [Accepted: 08/13/2023] [Indexed: 08/27/2023] Open
Abstract
Neovascular age-related macular degeneration (nAMD) is the primary disastrous retinal disease that leads to blindness in the elderly population. In the early 2000s, nAMD resulted in irreversible vision loss and blindness with no available treatment options. However, there have been breakthrough advances in the drug development of anti-angiogenic biological agents over the last two decades. The primary target molecule for treating nAMD is the vascular endothelial growth factor (VEGF), and there are currently several anti-VEGF drugs such as bevacizumab, ranibizumab, and aflibercept, which have made nAMD more manageable than before, thus preventing vision loss. Nevertheless, it should be noted that these anti-VEGF drugs for nAMD treatment are not effective in more than half of the patients, and even those who initially gain visual improvements lose their vision over time, along with potential deterioration in the geography of atrophy. As a result, there have been continuous endeavors to improve anti-VEGF agents through better efficacy, fewer doses, expanded intervals, and additional targets. This review describes past and current anti-VEGF therapeutics used to treat nAMD and outlines future directions to improve the effectiveness and safety of anti-VEGF agents.
Collapse
Affiliation(s)
- Bo-Hyun Moon
- Department of Oncology and Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA;
| | - Younghwa Kim
- Department of Paramedicine, Kyungil University, Gyeongsan-si 38428, Gyeongbuk, Republic of Korea
| | - Soo-Young Kim
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA 23298, USA
| |
Collapse
|
5
|
Fevereiro-Martins M, Marques-Neves C, Guimarães H, Bicho M. Retinopathy of prematurity: A review of pathophysiology and signaling pathways. Surv Ophthalmol 2023; 68:175-210. [PMID: 36427559 DOI: 10.1016/j.survophthal.2022.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 11/15/2022] [Accepted: 11/18/2022] [Indexed: 11/25/2022]
Abstract
Retinopathy of prematurity (ROP) is a vasoproliferative disorder of the retina and a leading cause of visual impairment and childhood blindness worldwide. The disease is characterized by an early stage of retinal microvascular degeneration, followed by neovascularization that can lead to subsequent retinal detachment and permanent visual loss. Several factors play a key role during the different pathological stages of the disease. Oxidative and nitrosative stress and inflammatory processes are important contributors to the early stage of ROP. Nitric oxide synthase and arginase play important roles in ischemia/reperfusion-induced neurovascular degeneration. Destructive neovascularization is driven by mediators of the hypoxia-inducible factor pathway, such as vascular endothelial growth factor and metabolic factors (succinate). The extracellular matrix is involved in hypoxia-induced retinal neovascularization. Vasorepulsive molecules (semaphorin 3A) intervene preventing the revascularization of the avascular zone. This review focuses on current concepts about signaling pathways and their mediators, involved in the pathogenesis of ROP, highlighting new potentially preventive and therapeutic modalities. A better understanding of the intricate molecular mechanisms underlying the pathogenesis of ROP should allow the development of more effective and targeted therapeutic agents to reduce aberrant vasoproliferation and facilitate physiological retinal vascular development.
Collapse
Affiliation(s)
- Mariza Fevereiro-Martins
- Laboratório de Genética and Grupo Ecogenética e Saúde Humana, Instituto de Saúde Ambiental, Faculdade de Medicina, Universidade de Lisboa, Portugal; Instituto de Investigação Científica Bento da Rocha Cabral, Lisboa, Portugal; Departamento de Oftalmologia, Hospital Cuf Descobertas, Lisboa, Portugal.
| | - Carlos Marques-Neves
- Centro de Estudos das Ci.¼ncias da Visão, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal; Grupo Ecogenética e Saúde Humana, Instituto de Saúde Ambiental, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
| | - Hercília Guimarães
- Departamento de Ginecologia-Obstetrícia e Pediatria, Faculdade de Medicina, Universidade do Porto, Porto, Portugal.
| | - Manuel Bicho
- Laboratório de Genética and Grupo Ecogenética e Saúde Humana, Instituto de Saúde Ambiental, Faculdade de Medicina, Universidade de Lisboa, Portugal; Instituto de Investigação Científica Bento da Rocha Cabral, Lisboa, Portugal.
| |
Collapse
|
6
|
Chen JC, Tu YC, Ho YW, Liang HC, Chen YF. Highly efficient diode-pumped passively Q-switched Nd:YVO 4/KGW Raman lasers at yellow and orange wavelengths. OPTICS EXPRESS 2023; 31:8696-8703. [PMID: 36859979 DOI: 10.1364/oe.486533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 02/15/2023] [Indexed: 06/18/2023]
Abstract
Efficient diode-pumped passively Q-switched Nd:YVO4 yellow and orange lasers are developed with the pulse pumping scheme and the intracavity stimulated Raman scattering (SRS) and second harmonic generation (SHG). A Np-cut KGW is exploited in the SRS process to generate the yellow 579 nm laser or the orange 589 nm laser in a selectable way. The high efficiency is achieved by designing a compact resonator to include a coupled cavity for intracavity SRS and SHG and to provide a focused beam waist on the saturable absorber for reaching an excellent passive Q-switching. The output pulse energy and peak power can reach 0.08 mJ and 50 kW for the orange laser at 589 nm. On the other hand, the output pulse energy and peak power can be up to 0.10 mJ and 80 kW for the yellow laser at 579 nm.
Collapse
|
7
|
Al Kawas H, Saaid I, Jank P, Westhoff CC, Denkert C, Pross T, Weiler KBS, Karsten MM. How VEGF-A and its splice variants affect breast cancer development - clinical implications. Cell Oncol (Dordr) 2022; 45:227-239. [PMID: 35303290 PMCID: PMC9050780 DOI: 10.1007/s13402-022-00665-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2022] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Altered expression levels and structural variations in the vascular endothelial growth factor (VEGF) have been found to play important roles in cancer development and to be associated with the overall survival and therapy response of cancer patients. Particularly VEGF-A and its splice variants have been found to affect physiological and pathological angiogenic processes, including tumor angiogenesis, correlating with tumor progression, mostly caused by overexpression. This review focuses on the expression and impact of VEGF-A splice variants under physiologic conditions and in tumors and, in particular, the distribution and role of isoform VEGF165b in breast cancer. CONCLUSIONS AND PERSPECTIVES Many publications already highlighted the importance of VEGF-A and its splice variants in tumor therapy, especially in breast cancer, which are summarized in this review. Furthermore, we were able to demonstrate that cytoplasmatic VEGFA/165b expression is higher in invasive breast cancer tumor cells than in normal tissues or stroma. These examples show that the detection of VEGF splice variants can be performed also on the protein level in formalin fixed tissues. Although no quantitative conclusions can be drawn, these results may be the starting point for further studies at a quantitative level, which can be a major step towards the design of targeted antibody-based (breast) cancer therapies.
Collapse
Affiliation(s)
- Hivin Al Kawas
- Department of Gynecology with Breast Center, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Inas Saaid
- Department of Gynecology with Breast Center, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Paul Jank
- Institute of Pathology, Philipps-Universität Marburg, 35043, Marburg, Germany
| | | | - Carsten Denkert
- Institute of Pathology, Philipps-Universität Marburg, 35043, Marburg, Germany
| | - Therese Pross
- Department of Gynecology with Breast Center, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | | | - Maria Margarete Karsten
- Department of Gynecology with Breast Center, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Charitéplatz 1, 10117, Berlin, Germany.
| |
Collapse
|
8
|
Tung JC, Liu KW, Chen SC. Generating multiple optical vortices in orange beams induced by selectively pumped frequency-doubled solid-state Raman lasers with mode conversion. OPTICS LETTERS 2022; 47:945-948. [PMID: 35167565 DOI: 10.1364/ol.444803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/02/2022] [Indexed: 06/14/2023]
Abstract
We employ a selectively pumped solid-state laser with stimulated Raman scattering and second-harmonic generation to generate frequency-doubled lasing modes (FDLMs) at 588 nm. The FDLMs are transformed by using an external cylindrical mode converter to generate various structured beams with multiple optical vortices. Theoretical analyses clearly reveal the relationship between the mode components in the laser emission and the transverse displacement of the off-center pumping. We further verify that the experimental results for the transformed FDLMs can be numerically reconstructed with a theoretical model. By analyzing the phase structures of the converted beams, it can be demonstrated that the number of vortices rises from 2 to 19 with increasing off-center displacement.
Collapse
|
9
|
Cornelius VA, Fulton JR, Margariti A. Alternative Splicing: A Key Mediator of Diabetic Vasculopathy. Genes (Basel) 2021; 12:1332. [PMID: 34573314 PMCID: PMC8469645 DOI: 10.3390/genes12091332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/24/2021] [Accepted: 08/24/2021] [Indexed: 12/25/2022] Open
Abstract
Cardiovascular disease is the leading cause of death amongst diabetic individuals. Atherosclerosis is the prominent driver of diabetic vascular complications, which is triggered by the detrimental effects of hyperglycemia and oxidative stress on the vasculature. Research has extensively shown diabetes to result in the malfunction of the endothelium, the main component of blood vessels, causing severe vascular complications. The pathogenic mechanism in which diabetes induces vascular dysfunction, however, remains largely unclear. Alternative splicing of protein coding pre-mRNAs is an essential regulatory mechanism of gene expression and is accepted to be intertwined with cellular physiology. Recently, a role for alternative splicing has arisen within vascular health, with aberrant mis-splicing having a critical role in disease development, including in atherosclerosis. This review focuses on the current knowledge of alternative splicing and the roles of alternatively spliced isoforms within the vasculature, with a particular focus on disease states. Furthermore, we explore the recent elucidation of the alternatively spliced QKI gene within vascular cell physiology and the onset of diabetic vasculopathy. Potential therapeutic strategies to restore aberrant splicing are also discussed.
Collapse
Affiliation(s)
| | | | - Andriana Margariti
- The Wellcome-Wolfson Institute of Experimental Medicine, Belfast BT9 7BL, UK; (V.A.C.); (J.R.F.)
| |
Collapse
|
10
|
Magnussen AL, Mills IG. Vascular normalisation as the stepping stone into tumour microenvironment transformation. Br J Cancer 2021; 125:324-336. [PMID: 33828258 PMCID: PMC8329166 DOI: 10.1038/s41416-021-01330-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 01/17/2021] [Accepted: 02/17/2021] [Indexed: 02/01/2023] Open
Abstract
A functional vascular system is indispensable for drug delivery and fundamental for responsiveness of the tumour microenvironment to such medication. At the same time, the progression of a tumour is defined by the interactions of the cancer cells with their surrounding environment, including neovessels, and the vascular network continues to be the major route for the dissemination of tumour cells in cancer, facilitating metastasis. So how can this apparent conflict be reconciled? Vessel normalisation-in which redundant structures are pruned and the abnormal vasculature is stabilised and remodelled-is generally considered to be beneficial in the course of anti-cancer treatments. A causality between normalised vasculature and improved response to medication and treatment is observed. For this reason, it is important to discern the consequence of vessel normalisation on the tumour microenvironment and to modulate the vasculature advantageously. This article will highlight the challenges of controlled neovascular remodelling and outline how vascular normalisation can shape disease management.
Collapse
Affiliation(s)
- Anette L Magnussen
- Nuffield Department of Surgical Sciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Ian G Mills
- Nuffield Department of Surgical Sciences, University of Oxford, John Radcliffe Hospital, Oxford, UK.
- Patrick G Johnston Centre for Cancer Research, Queen's University of Belfast, Belfast, UK.
- Centre for Cancer Biomarkers, University of Bergen, Bergen, Norway.
- Department of Clinical Science, University of Bergen, Bergen, Norway.
| |
Collapse
|
11
|
Dailey W, Shunemann R, Yang F, Moore M, Knapp A, Chen P, Deshpande M, Metcalf B, Tompkins Q, Guzman AE, Felisky J, Mitton KP. Differences in activation of intracellular signaling in primary human retinal endothelial cells between isoforms of VEGFA 165. Mol Vis 2021; 27:191-205. [PMID: 33953532 PMCID: PMC8092446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 04/26/2021] [Indexed: 11/18/2022] Open
Abstract
Purpose There are reports that a b-isoform of vascular endothelial growth factor-A 165 (VEGFA165b) is predominant in normal human vitreous, switching to the a-isoform (VEGFA165a) in the vitreous of some diseased eyes. Although these isoforms appear to have a different ability to activate the VEGF receptor 2 (VEGFR2) in various endothelial cells, the nature of their ability to activate intracellular signaling pathways is not fully characterized, especially in retinal endothelial cells. We determined their activation potential for two key intracellular signaling pathways (MAPK, AKT) over complete dose-response curves and compared potential effects on the expression of several VEGFA165 target genes in primary human retinal microvascular endothelial cells (HRMECs). Methods To determine full dose-response curves for the activation of MAPK (ERK1/2), AKT, and VEGFR2, direct in-cell western assays were developed using primary HRMECs. Potential differences in dose-response effects on gene expression markers related to endothelial cell and leukocyte adhesion (ICAM1, VCAM1, and SELE) and tight junctions (CLDN5 and OCLN) were tested with quantitative PCR. Results Activation dose-response analysis revealed much stronger activation of MAPK, AKT, and VEGFR2 by the a-isoform at lower doses. MAPK activation in primary HRMECs displayed a sigmoidal dose-response to a range of VEGFA 165 a concentrations spanning 10-250 pM, which shifted higher into the 100-5,000 pM range with VEGFA 165 b. Similar maximum activation of MAPK was achieved by both isoforms at high concentrations. Maximum activation of AKT by VEGFA 165 b was only half of the maximum activation from VEGFA 165 a. At a lower intermediate dose, where VEGFA 165 a activated intracellular signaling stronger than VEGFA 165 b, the changes in VEGFA target gene expression were generally greater with VEGFA 165 a. Conclusions In primary HRMECs, VEGFA 165 a could maximally activate MAPK and AKT at lower concentrations where VEGFA 165 b had relatively little effect. The timing for maximum activation of MAPK was similar for the isoforms, which is different from that reported for non-retinal endothelial cells. Although differences in VEGFA 165 a and VEGFA 165 b are limited to the sequence of their six C-terminal six amino acids, this results in a large difference in their ability to activate at least two key intracellular signaling pathways and VEGF-target gene expression in primary human retinal endothelial cells.
Collapse
|
12
|
Hernández-Morales J, Hernández-Coronado CG, Guzmán A, Zamora-Gutiérrez D, Fierro F, Gutiérrez CG, Rosales-Torres AM. Hypoxia up-regulates VEGF ligand and downregulates VEGF soluble receptor mRNA expression in bovine granulosa cells in vitro. Theriogenology 2021; 165:76-83. [PMID: 33640589 DOI: 10.1016/j.theriogenology.2021.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 02/04/2021] [Accepted: 02/07/2021] [Indexed: 11/29/2022]
Abstract
Oxygen concentration (02) in antral ovarian follicles is below that found in most tissues, which is important for adequate granulosa cell function. The VEGF system is linked to angiogenesis and responds to changing 02 by stimulating neovascularization when levels are low. However, in the avascular granulosa cell layer of the follicle, VEGF action is directed to stimulating cell viability and steroidogenesis. The aim of this study was to examine the effect of 02 concentration on granulosa cell expression of the VEGF-system components. Bovine granulosa cells were isolated from medium-sized follicles (4-7 mm in diameter), placed in McCoy 5a medium supplemented with 10 ng/mL of insulin, 1 ng/mL of IGF-I, and 1 ng/mL of FSH, and cultured in four well plates (500 thousand cells per well), on three separate occasions. Culture plates were placed in gas-impermeable jars with a gas mixture containing either 2%, or 5% of O2, or under atmospheric air condition inside an incubator (20% of 02). Media was replaced at 48 h of culture and cells from the plate in each oxygen concentration were pooled for RNA extraction after 96 h. The number of mRNA copies for the VEGF-system components - including ligands (VEGF120, VEGF120b, VEGF165 and VEGF165b), enzymes (cyclin-dependent like kinases-1, CLK1 and serine-arginine protein kinase 1, SRPK1), splicing factors (serine-arginine-rich splicing factors, SRSF1 and SRSF6), and the membrane-bound (VEGFR1, VEGFR2) and soluble forms of the receptors (sVEGFR1 and sVEGFR2) were quantified by qPCR. Granulosa cells cultured with low 02 (2%) had a higher expression of VEGF ligands (P < 0.05) when compared to cells cultured at 20% 02. VEGF164b mRNA was absent in granulosa cells from all culture conditions. The 2 and 5% 02 levels, which coincide with physiological concentrations, in the ovarian follicle, induced higher SRSF6 expression than atmospheric 02 concentrations (20%, P < 0.05). In contrast, mRNA copies for SRPK1, CLK1, SRSF1, VEGFR1 or VEGFR2 did not differ between 02 culture conditions. (P > 0.05). Nonetheless, mRNA copies for the soluble receptors, sVEGFR1 and sVEGFR2, linearly increased (P < 0.05) with 02 concentration. These results suggest that when cultured under hypoxic conditions, granulosa cells may develop an autocrine milieu that favors VEGF's biological effects on their survival and function.
Collapse
Affiliation(s)
- Jahdai Hernández-Morales
- División de Ciencias Biológicas y de la Salud, Estudiante de Maestría en Biología de la Reproducción, Universidad Autónoma Metropolitana-Iztapalapa, Ciudad de México, Mexico
| | - Cyndi G Hernández-Coronado
- Universidad Nacional Autónoma de México, Facultad de Medicina Veterinaria y Zootecnia, Ciudad de México, Mexico
| | - Adrian Guzmán
- Departamento Producción Agrícola y Animal, Universidad Autónoma Metropolitana-Xochimilco, Ciudad de México, Mexico
| | - Diana Zamora-Gutiérrez
- Doctorado en Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana-Xochimilco, Ciudad de México, Mexico
| | - Francisco Fierro
- Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, Ciudad de México, Mexico
| | - Carlos G Gutiérrez
- Universidad Nacional Autónoma de México, Facultad de Medicina Veterinaria y Zootecnia, Ciudad de México, Mexico
| | - Ana Ma Rosales-Torres
- Departamento Producción Agrícola y Animal, Universidad Autónoma Metropolitana-Xochimilco, Ciudad de México, Mexico.
| |
Collapse
|
13
|
Chen YF, Li D, Lee YM, Lee CC, Huang HY, Tsou CH, Liang HC. Highly efficient solid-state Raman yellow-orange lasers created by enhancing the cavity reflectivity. OPTICS LETTERS 2021; 46:797-800. [PMID: 33577517 DOI: 10.1364/ol.415437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
A new, to the best of our knowledge, output coupler (OC) with enhancement of the cavity reflectivity is proposed to remarkably elevate the output powers and efficiencies of diode-pumped Nd:GdVO4/KGW Raman yellow-orange lasers. The cavity reflectivity is effectively increased by using the double-sided dichroic coating on the OC. In comparison with the conventional single-sided coating, the conversion efficiency can be boosted from 15% to 26.3% in the experiment of a yellow laser at 578.8 nm, and the maximum output power can be increased from 5.7 to 10.5 W in the quasi-continuous-wave mode with 50% duty cycle and frequency of 500 Hz. Furthermore, in the operation of an orange laser at 588 nm, the maximum output power can be improved from 5.6 to 7.0 W by replacing the conventional OC with the new one.
Collapse
|
14
|
Chen YF, Huang HY, Lee CC, Hsiao JQ, Tsou CH, Liang HC. High-power diode-pumped Nd:GdVO 4/KGW Raman laser at 578 nm. OPTICS LETTERS 2020; 45:5562-5565. [PMID: 33001947 DOI: 10.1364/ol.406173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 09/04/2020] [Indexed: 06/11/2023]
Abstract
A diode-pumped neodymium-doped gadolinium vanadate (Nd:GdVO4) laser is developed as a compact efficient yellow light at 578 nm by means of intracavity stimulated Raman scattering (SRS) in a potassium gadolinium tungstate (KGW) crystal and the second-harmonic generation in a lithium triborate crystal. The SRS process with a shift of 768cm-1 is achieved by setting the polarization of the fundamental wave along the Ng axis of the KGW crystal. The self-Raman effect arising from the Nd:GdVO4 crystal is systematically explored by employing two kinds of coating specification for the output coupler. With a specific coating on the output coupler to suppress the self-Raman effect, the maximum output power at 578 nm can reach 3.1 W at a pump power of 32 W. Moreover, two different lengths for the Nd:GdVO4 crystal are individually used to verify the influence of the self-Raman effect on the lasing efficiency.
Collapse
|
15
|
Chen YF, Chen CM, Lee CC, Huang HY, Li D, Hsiao JQ, Tsou CH, Liang HC. Efficient solid-state Raman yellow laser at 579.5 nm. OPTICS LETTERS 2020; 45:5612-5615. [PMID: 33001961 DOI: 10.1364/ol.405970] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 09/04/2020] [Indexed: 06/11/2023]
Abstract
A highly efficient diode-pumped Nd:YVO4/KGW Raman yellow laser is developed to produce a 6.8 W yellow light at 579.5 nm accompanied by a 3.2 W Stokes wave at 1159 nm under an incident pump power of 30 W. The intracavity stimulated Raman scattering with the shift of 768cm-1 is generated by setting the polarization of the fundamental wave along the Ng direction of an Np-cut KGW crystal. The Nd:YVO4 gain medium is coated as a cavity mirror to reduce the cavity losses for the fundamental wave. More importantly, the KGW crystal is specially coated to prevent the Stokes wave from propagating through the gain medium to minimize the cavity losses for the Stokes wave.
Collapse
|
16
|
Lyzogubov V, Dasso M, Bora N, Bora PS. Role of thalidomide, senicapoc, and sodium butyrate in choroidal neovascularization. Biochem Biophys Res Commun 2020; 530:367-373. [PMID: 32800337 DOI: 10.1016/j.bbrc.2020.07.140] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 07/29/2020] [Indexed: 02/06/2023]
Abstract
Choroidal neovascularization (CNV) is the hallmark of wet age-related macular degeneration (AMD), a leading cause of irreversible blindness in the modern world. The objective for this study was to investigate the therapeutic potential of known antiangiogenic agents: thalidomide, senicapoc, and sodium butyrate. Dose-dependent effect of the agents on growth of ARPE-19 cells and human umbilical vein endothelial cells (HUVECs) was investigated with cell counting assays. Half-maximal inhibitory concentrations of thalidomide (765 μM and 1520 μM), senicapoc (50 μM and 79 μM), and sodium butyrate (933 μM and 557 μM) were determined for HUVECs and ARPE-19 cells, respectively. Immunofluorescence analysis showed decrease of VEGFA expression in both ARPE-19 cells and HUVECs after treatment only with thalidomide but not with senicapoc or sodium butyrate. Efficacy of the agents was studied in vivo with laser-induced CNV in C57BL/6 mice. Thalidomide (24 μg), senicapoc (4 μg), or sodium butyrate (100 μg) was intravitreally injected the day after CNV induction. Thalidomide, senicapoc, and sodium butyrate inhibited CNV size by 56%, 24%, and 21% respectively on day 7 post-laser. Thalidomide also reduced cobalt chloride induced increase of VEGFA mRNA in ARPE-19 (-33%) and protein in culture medium (-20%). Our results suggest that thalidomide may have more therapeutic potential than senicapoc or sodium butyrate for treatment of CNV or wet AMD.
Collapse
Affiliation(s)
- Valeriy Lyzogubov
- Department of Ophthalmology, Jones Eye Institute, Pat & Willard Walker Eye Research Center and College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham St, Little Rock, AR, 72205, USA.
| | - Michael Dasso
- Department of Ophthalmology, Jones Eye Institute, Pat & Willard Walker Eye Research Center and College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham St, Little Rock, AR, 72205, USA.
| | - Nalini Bora
- Department of Ophthalmology, Jones Eye Institute, Pat & Willard Walker Eye Research Center and College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham St, Little Rock, AR, 72205, USA.
| | - Puran S Bora
- Department of Ophthalmology, Jones Eye Institute, Pat & Willard Walker Eye Research Center and College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham St, Little Rock, AR, 72205, USA.
| |
Collapse
|
17
|
Dardente H, English WR, Valluru MK, Kanthou C, Simpson D. Debunking the Myth of the Endogenous Antiangiogenic Vegfaxxxb Transcripts. Trends Endocrinol Metab 2020; 31:398-409. [PMID: 32396842 DOI: 10.1016/j.tem.2020.01.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/28/2019] [Accepted: 01/14/2020] [Indexed: 12/19/2022]
Abstract
In this opinion article we critically assess evidence for the existence of a family of antiangiogenic vascular endothelial growth factor (Vegfaxxxb) transcripts, arising from the use of a phylogenetically conserved alternative distal splice site within exon 8 of the VEGFA gene. We explain that prior evidence for Vegfaxxxb transcripts in tissues rests heavily upon flawed RT-PCR methodologies, with the extensive use of 5'-tailing in primer design being the main issue. Furthermore, our analysis of large RNA-seq data sets (human and ovine) fails to identify a single Vegfaxxxb transcript. Therefore, we challenge the very existence of Vegfaxxxb transcripts, which further questions the physiological relevance of studies based on the use of 'anti-VEGFAxxxb' antibodies. Our analysis has implications for the proposed therapeutic use of isoform-specific anti-VEGFA strategies for treating cancer and retinopathies.
Collapse
Affiliation(s)
- Hugues Dardente
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380 Nouzilly, France.
| | - William R English
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - Manoj K Valluru
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - Chryso Kanthou
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - David Simpson
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, BT7 1NN, UK
| |
Collapse
|
18
|
Jiang F, Chong L, Du S, Duan Y, Wang Y, Wang J, Chen S, He T. Decreased Ratio of VEGF165b/VEGF in Aqueous Humor Predicts Progression of Diabetic Retinopathy. Ophthalmic Res 2020; 63:517-523. [PMID: 32344407 DOI: 10.1159/000508250] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/27/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND Different splicing of vascular endothelial growth factor (VEGF) gene results in 2 families of VEGF, the proangiogenic isoforms (VEGFxxxa) and the antiangiogenic isoforms (VEGFxxxb). VEGF165b is the major antiangiogenic isoform of VEGF and the most studied member of the VEGFxxxb family so far. OBJECTIVES To determine the concentration of VEGF165b and VEGF in the aqueous humor (AH) in diabetic eyes with or without diabetic retinopathy (DR) and to address the predictive value of VEGF165b/VEGF ratio for progression of DR. METHODS AH samples from 20 eyes in healthy controls (CON group), 40 eyes in diabetic patients without DR (nDR group), and 30 eyes in diabetic patients with mild nonproliferative DR (DR group) were collected. All of the patients were followed up for at least 5 years. VEGF165b and VEGF levels of AH samples were measured by enzyme-linked immunosorbent assay (ELISA). The predictive value of the initial VEGF165b/VEGF ratio for progression of DR was studied. RESULTS The mean concentration of VEGF165b significantly decreased in diabetic eyes vs. controls. The mean concentration of VEGF significantly increased in the DR group vs. the CON group. The VEGF165b/VEGF ratio was significantly lower in diabetic patients compared to the CON group. The VEGF165b/VEGF ratio was significantly lower in diabetic patients compared to the control group. The mean follow-up was 66.1months (range 60-71 months). The risk of DR progression was greater with a lower VEGF165b/VEGF ratio. CONCLUSION The VEGF165b/VEGF ratio is lower in the AH of DR patients and the decreased ratio of VEGF165b/VEGF predicts DR progression.
Collapse
Affiliation(s)
- Feng Jiang
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin, China
| | - Liuyun Chong
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin, China
| | - Shufang Du
- Department of Ophthalmology, Shanxi Eye Hospital, Taiyuan City, China
| | - Yajian Duan
- Department of Ophthalmology, Shanxi Eye Hospital, Taiyuan City, China
| | - Ying Wang
- Department of Ophthalmology, Shenyang Aier Eye Hospital, Shenyang City, China
| | - Jiaxing Wang
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | - Song Chen
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin, China,
| | - Tiangeng He
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin, China
| |
Collapse
|
19
|
Porta M, Striglia E. Intravitreal anti-VEGF agents and cardiovascular risk. Intern Emerg Med 2020; 15:199-210. [PMID: 31848994 DOI: 10.1007/s11739-019-02253-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 12/03/2019] [Indexed: 12/20/2022]
Abstract
Antagonists of Vascular Endothelial Growth Factor (Anti-VEGF) are widely administered by intravitreal injection for the treatment of ocular pathologies such as Age-related Macular Degeneration, Diabetic Macular Edema, Proliferative Diabetic Retinopathy and occlusion of retinal vessels. Anti-VEGF agents, in particular bevacizumab, were introduced in oncology to inhibit tumor-induced angiogenesis feeding neoplastic tissues. Subsequently, other specific agents were developed for intraocular administration. Whereas systemic administration of anti-VEGF agents in oncology is burdened by increased risk of arterial hypertension and embolism, agents administered for ophthalmic indications are delivered locally into the eye globe in much smaller quantities. Nevertheless, clinical observations have raised the possibility that, even in these conditions, anti-VEGF agents may increase cardiovascular risk in patients who, being elderly and/or diabetic, are intrinsically prone to such events. This paper aims at reviewing the current knowledge on VEGF and its pharmacologic antagonists from mechanistic and side effect points of view, with specific reference to patients with sight-threatening conditions. Internists should be aware of the need to collaborate with ophthalmologists and pharmacovigilance operators to define as best as possible the risk/benefit balance of intravitreal agents in patients who might lose their sight if left untreated, or increase their risk of suffering a cardiovascular event if treated.
Collapse
Affiliation(s)
- Massimo Porta
- Department of Medical Sciences, University of Turin, Corso AM Dogliotti 14, 10126, Turin, Italy.
| | - Elio Striglia
- Department of Medical Sciences, University of Turin, Corso AM Dogliotti 14, 10126, Turin, Italy
| |
Collapse
|
20
|
Pielen A, Feltgen N, Hattenbach LO, Hoerauf H, Bertelmann T, Quiering C, Vögeler J, Priglinger S, Lang GE, Schmitz-Valckenberg S, Wolf A, Rehak M. Ranibizumab Pro Re nata versus Dexamethasone in the Management of Ischemic Retinal Vein Occlusion: Post-hoc Analysis from the COMRADE Trials. Curr Eye Res 2019; 45:604-614. [PMID: 31665935 DOI: 10.1080/02713683.2019.1679839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Purpose: To compare ischemia-related clinical outcomes in patients treated with either ranibizumab pro re nata (PRN) or single dexamethasone implant in the Branch Retinal Vein Occlusion (COMRADE-B) or Central Retinal Vein Occlusion (COMRADE-C) trials.Methods: A post-hoc analysis of the Phase IIIb, 6-month, multicenter, double-masked, randomized, COMRADE-B and COMRADE-C trials. Change over 6 months in retinal ischemia status (central avascular [CA] zone and peripheral nonperfusion [PNP]), mean best-corrected visual acuity (BCVA), the development of shunt vessels and neovascularization, and frequency of laser therapy were assessed in retinal vein occlusion (RVO) patients treated with either ranibizumab 0.5 mg PRN or single dexamethasone 0.7 mg implant, as per European labels, in the COMRADE-B (N = 244; ranibizumab, 126, dexamethasone, 118) or COMRADE-C (N = 243; ranibizumab, 124, dexamethasone, 119) trials. BCVA progression in ischemic vs. non-ischemic patients based on the ischemia assessment at month 6 was carried out.Results: Visual acuity (VA) gains from baseline to month 6 were higher with ranibizumab than with dexamethasone in both patients with central ischemia and those with peripheral retinal nonperfusion, independent of the type of RVO (branch or central). The presence of CA and PNP had a significant impact on VA gain over 6 months in CRVO patients (p < .0001), while there was no significant impact in BRVO. Ranibizumab was associated with less new ischemia than dexamethasone. Central RVO patients treated with dexamethasone received more laser treatments over the 6 months than those treated with ranibizumab, while there was no difference in the frequency of laser therapy between the branch RVO treatment groups.Conclusions: VA gain over six months in ranibizumab-treated RVO patients is not affected by ischemia, and is associated with less development of new ischemia during the first 6 months of treatment and equal or fewer laser treatments than dexamethasone implant.
Collapse
Affiliation(s)
- Amelie Pielen
- Hannover Medical School, University Eye Hospital, Hannover, Germany.,Eye Center, University Medical Center Freiburg, Freiburg, Germany
| | - Nicolas Feltgen
- Eye Hospital, University Medical Center, Goettingen, Germany
| | | | - Hans Hoerauf
- Eye Hospital, University Medical Center, Goettingen, Germany
| | | | - Claudia Quiering
- Department of Ophthalmology, Novartis Pharma GmbH, Nuremberg, Germany
| | - Jessica Vögeler
- Department of Ophthalmology, Novartis Pharma GmbH, Nuremberg, Germany
| | - Siegfried Priglinger
- Department of Ophthalmology, University Eye Hospital, Ludwig Maximilian Universität, München, Germany
| | - Gabriele E Lang
- Department of Ophthalmology, University Eye Hospital Ulm, Ulm, Germany
| | | | - Armin Wolf
- Department of Ophthalmology, University Eye Hospital, Ludwig Maximilian Universität, München, Germany
| | - Matus Rehak
- Eye Hospital, Universitätsklinikum Leipzig, Leipzig, Germany
| |
Collapse
|
21
|
Stevens M, Star E, Lee M, Innes E, Li L, Bowler E, Harper S, Bates DO, Oltean S. The VEGF-A exon 8 splicing-sensitive fluorescent reporter mouse is a novel tool to assess the effects of splicing regulatory compounds in vivo. RNA Biol 2019; 16:1672-1681. [PMID: 31432737 PMCID: PMC6844573 DOI: 10.1080/15476286.2019.1652522] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Vascular endothelial growth factor (VEGF)-A is differentially spliced to give two functionally different isoform families; pro-angiogenic, pro-permeability VEGF-Axxx and anti-angiogenic, anti-permeability VEGF-Axxxb. VEGF-A splicing is dysregulated in several pathologies, including cancer, diabetes, and peripheral arterial disease. The bichromatic VEGF-A splicing-sensitive fluorescent reporter harboured in a transgenic mouse is a novel approach to investigate the splicing patterns of VEGF-A in vivo. We generated a transgenic mouse harbouring a splicing-sensitive fluorescent reporter designed to mimic VEGF-A terminal exon splicing (VEGF8ab) by insertion into the ROSA26 genomic locus. dsRED expression denotes proximal splice site selection (VEGF-Axxx) and eGFP expression denotes distal splice site selection (VEGF-Axxxb). We investigated the tissue-specific expression patterns in the eye, skeletal muscle, cardiac muscle, kidney, and pancreas, and determined whether the splicing pattern could be manipulated in the same manner as endogenous VEGF-A by treatment with the SRPK1 inhibitor SPHINX 31. We confirmed expression of both dsRED and eGFP in the eye, skeletal muscle, cardiac muscle, kidney, and pancreas, with the highest expression of both fluorescent proteins observed in the exocrine pancreas. The ratio of dsRED and eGFP matched that of endogenous VEGF-Axxx and VEGF-Axxxb. Treatment of the VEGF8ab mice with SPHINX 31 increased the mRNA and protein eGFP/dsRED ratio in the exocrine pancreas, mimicking endogenous VEGF-A splicing. The VEGF-A exon 8 splicing-sensitive fluorescent reporter mouse is a novel tool to assess splicing regulation in the individual cell-types and tissues, which provides a useful screening process for potentially therapeutic splicing regulatory compounds in vivo.
Collapse
Affiliation(s)
- M Stevens
- Institute of Biomedical and Clinical Science, Medical School, College of Medicine and Health, University of Exeter, Exeter, UK
| | - E Star
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, UK
| | - M Lee
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, UK
| | - E Innes
- Institute of Biomedical and Clinical Science, Medical School, College of Medicine and Health, University of Exeter, Exeter, UK
| | - L Li
- Institute of Biomedical and Clinical Science, Medical School, College of Medicine and Health, University of Exeter, Exeter, UK
| | - E Bowler
- Institute of Biomedical and Clinical Science, Medical School, College of Medicine and Health, University of Exeter, Exeter, UK
| | - S Harper
- Institute of Biomedical and Clinical Science, Medical School, College of Medicine and Health, University of Exeter, Exeter, UK.,School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK
| | - D O Bates
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham, UK
| | - S Oltean
- Institute of Biomedical and Clinical Science, Medical School, College of Medicine and Health, University of Exeter, Exeter, UK
| |
Collapse
|
22
|
Endogenous Antiangiogenic Factors in Chronic Kidney Disease: Potential Biomarkers of Progression. Int J Mol Sci 2018; 19:ijms19071859. [PMID: 29937525 PMCID: PMC6073618 DOI: 10.3390/ijms19071859] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Revised: 06/17/2018] [Accepted: 06/22/2018] [Indexed: 12/17/2022] Open
Abstract
Chronic kidney disease (CKD) is a major global health problem. Unless intensive intervention is initiated, some patients can rapidly progress to end-stage kidney disease. However, it is often difficult to predict renal outcomes using conventional laboratory tests in individuals with CKD. Therefore, many researchers have been searching for novel biomarkers to predict the progression of CKD. Angiogenesis is involved in physiological and pathological processes in the kidney and is regulated by the balance between a proangiogenic factor, vascular endothelial growth factor (VEGF)-A, and various endogenous antiangiogenic factors. In recent reports using genetically engineered mice, the roles of these antiangiogenic factors in the pathogenesis of kidney disease have become increasingly clear. In addition, recent clinical studies have demonstrated associations between circulating levels of antiangiogenic factors and renal dysfunction in CKD patients. In this review, we summarize recent advances in the study of representative endogenous antiangiogenic factors, including soluble fms-related tyrosine kinase 1, soluble endoglin, pigment epithelium-derived factor, VEGF-A165b, endostatin, and vasohibin-1, in associations with kidney diseases and discuss their predictive potentials as biomarkers of progression of CKD.
Collapse
|
23
|
Bates DO, Beazley-Long N, Benest AV, Ye X, Ved N, Hulse RP, Barratt S, Machado MJ, Donaldson LF, Harper SJ, Peiris-Pages M, Tortonese DJ, Oltean S, Foster RR. Physiological Role of Vascular Endothelial Growth Factors as Homeostatic Regulators. Compr Physiol 2018; 8:955-979. [PMID: 29978898 DOI: 10.1002/cphy.c170015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The vascular endothelial growth factor (VEGF) family of proteins are key regulators of physiological systems. Originally linked with endothelial function, they have since become understood to be principal regulators of multiple tissues, both through their actions on vascular cells, but also through direct actions on other tissue types, including epithelial cells, neurons, and the immune system. The complexity of the five members of the gene family in terms of their different splice isoforms, differential translation, and specific localizations have enabled tissues to use these potent signaling molecules to control how they function to maintain their environment. This homeostatic function of VEGFs has been less intensely studied than their involvement in disease processes, development, and reproduction, but they still play a substantial and significant role in healthy control of blood volume and pressure, interstitial volume and drainage, renal and lung function, immunity, and signal processing in the peripheral and central nervous system. The widespread expression of VEGFs in healthy adult tissues, and the disturbances seen when VEGF signaling is inhibited support this view of the proteins as endogenous regulators of normal physiological function. This review summarizes the evidence and recent breakthroughs in understanding of the physiology that is regulated by VEGF, with emphasis on the role they play in maintaining homeostasis. © 2017 American Physiological Society. Compr Physiol 8:955-979, 2018.
Collapse
Affiliation(s)
- David O Bates
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | | | - Andrew V Benest
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Xi Ye
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Nikita Ved
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Richard P Hulse
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Shaney Barratt
- Academic Respiratory Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Maria J Machado
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Lucy F Donaldson
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Steven J Harper
- School of Physiology, Pharmacology & Neuroscience, Medical School, University of Bristol, Bristol, United Kingdom
| | - Maria Peiris-Pages
- Cancer Research UK Manchester Institute, The University of Manchester, Manchester, United Kingdom
| | - Domingo J Tortonese
- Centre for Comparative and Clinical Anatomy, University of Bristol, Bristol, United Kingdom
| | - Sebastian Oltean
- Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom
| | - Rebecca R Foster
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
24
|
Regulation of human feto-placental endothelial barrier integrity by vascular endothelial growth factors: competitive interplay between VEGF-A 165a, VEGF-A 165b, PIGF and VE-cadherin. Clin Sci (Lond) 2017; 131:2763-2775. [PMID: 29054861 PMCID: PMC5869853 DOI: 10.1042/cs20171252] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 10/03/2017] [Accepted: 10/19/2017] [Indexed: 02/07/2023]
Abstract
The human placenta nourishes and protects the developing foetus whilst influencing maternal physiology for fetal advantage. It expresses several members of the vascular endothelial growth factor (VEGF) family including the pro-angiogenic/pro-permeability VEGF-A165a isoform, the anti-angiogenic VEGF-A165b, placental growth factor (PIGF) and their receptors, VEGFR1 and VEGFR2. Alterations in the ratio of these factors during gestation and in complicated pregnancies have been reported; however, the impact of this on feto-placental endothelial barrier integrity is unknown. The present study investigated the interplay of these factors on junctional occupancy of VE-cadherin and macromolecular leakage in human endothelial monolayers and the perfused placental microvascular bed. Whilst VEGF-A165a (50 ng/ml) increased endothelial monolayer albumin permeability (P<0.0001), equimolar concentrations of VEGF-A165b (P>0.05) or PlGF (P>0.05) did not. Moreover, VEGF-A165b (100 ng/ml; P<0.001) but not PlGF (100 ng/ml; P>0.05) inhibited VEGF-A165a-induced permeability when added singly. PlGF abolished the VEGF-A165b-induced reduction in VEGF-A165a-mediated permeability (P>0.05); PlGF was found to compete with VEGF-A165b for binding to Flt-1 at equimolar affinity. Junctional occupancy of VE-cadherin matched alterations in permeability. In the perfused microvascular bed, VEGF-A165b did not induce microvascular leakage but inhibited and reversed VEGF-A165a-induced loss of junctional VE-cadherin and tracer leakage. These results indicate that the anti-angiogenic VEGF-A165b isoform does not increase permeability in human placental microvessels or HUVEC primary cells and can interrupt VEGF-A165a-induced permeability. Moreover, the interplay of these isoforms with PIGF (and s-flt1) suggests that the ratio of these three factors may be important in determining the placental and endothelial barrier in normal and complicated pregnancies.
Collapse
|
25
|
A Critical Analysis of the Available In Vitro and Ex Vivo Methods to Study Retinal Angiogenesis. J Ophthalmol 2017; 2017:3034953. [PMID: 28848677 PMCID: PMC5564124 DOI: 10.1155/2017/3034953] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 06/20/2017] [Accepted: 06/28/2017] [Indexed: 12/15/2022] Open
Abstract
Angiogenesis is a biological process with a central role in retinal diseases. The choice of the ideal method to study angiogenesis, particularly in the retina, remains a problem. Angiogenesis can be assessed through in vitro and in vivo studies. In spite of inherent limitations, in vitro studies are faster, easier to perform and quantify, and typically less expensive and allow the study of isolated angiogenesis steps. We performed a systematic review of PubMed searching for original articles that applied in vitro or ex vivo angiogenic retinal assays until May 2017, presenting the available assays and discussing their applicability, advantages, and disadvantages. Most of the studies evaluated migration, proliferation, and tube formation of endothelial cells in response to inhibitory or stimulatory compounds. Other aspects of angiogenesis were studied by assessing cell permeability, adhesion, or apoptosis, as well as by implementing organotypic models of the retina. Emphasis is placed on how the methods are applied and how they can contribute to retinal angiogenesis comprehension. We also discuss how to choose the best cell culture to implement these methods. When applied together, in vitro and ex vivo studies constitute a powerful tool to improve retinal angiogenesis knowledge. This review provides support for researchers to better select the most suitable protocols in this field.
Collapse
|
26
|
Antiangiogenic Therapy for Diabetic Nephropathy. BIOMED RESEARCH INTERNATIONAL 2017; 2017:5724069. [PMID: 28835895 PMCID: PMC5556994 DOI: 10.1155/2017/5724069] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 05/16/2017] [Accepted: 06/13/2017] [Indexed: 12/28/2022]
Abstract
Angiogenesis has been shown to be a potential therapeutic target for early stages of diabetic nephropathy in a number of animal experiments. Vascular endothelial growth factor (VEGF) is the main mediator for abnormal angiogenesis in diabetic glomeruli. Although beneficial effects of anti-VEGF antibodies have previously been demonstrated in diabetic animal experiments, recent basic and clinical evidence has revealed that the blockade of VEGF signaling resulted in proteinuria and renal thrombotic microangiopathy, suggesting the importance of maintaining normal levels of VEGF in the kidneys. Therefore, antiangiogenic therapy for diabetic nephropathy should eliminate excessive glomerular angiogenic response without accelerating endothelial injury. Some endogenous antiangiogenic factors such as endostatin and tumstatin inhibit overactivation of endothelial cells but do not specifically block VEGF signaling. In addition, the novel endothelium-derived antiangiogenic factor vasohibin-1 enhances stress tolerance and survival of the endothelial cells, while inhibiting excess angiogenesis. These factors have been demonstrated to suppress albuminuria and glomerular alterations in a diabetic mouse model. Thus, antiangiogenic therapy with promising candidates will possibly improve renal prognosis in patients with early stages of diabetic nephropathy.
Collapse
|
27
|
Vascular endothelial growth factor-A 165b ameliorates outer-retinal barrier and vascular dysfunction in the diabetic retina. Clin Sci (Lond) 2017; 131:1225-1243. [PMID: 28341661 PMCID: PMC5450016 DOI: 10.1042/cs20170102] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/09/2017] [Accepted: 03/24/2017] [Indexed: 01/11/2023]
Abstract
Diabetic retinopathy (DR) is one of the leading causes of blindness in the developed world. Characteristic features of DR are retinal neurodegeneration, pathological angiogenesis and breakdown of both the inner and outer retinal barriers of the retinal vasculature and retinal pigmented epithelial (RPE)–choroid respectively. Vascular endothelial growth factor (VEGF-A), a key regulator of angiogenesis and permeability, is the target of most pharmacological interventions of DR. VEGF-A can be alternatively spliced at exon 8 to form two families of isoforms, pro- and anti-angiogenic. VEGF-A165a is the most abundant pro-angiogenic isoform, is pro-inflammatory and a potent inducer of permeability. VEGF-A165b is anti-angiogenic, anti-inflammatory, cytoprotective and neuroprotective. In the diabetic eye, pro-angiogenic VEGF-A isoforms are up-regulated such that they overpower VEGF-A165b. We hypothesized that this imbalance may contribute to increased breakdown of the retinal barriers and by redressing this imbalance, the pathological angiogenesis, fluid extravasation and retinal neurodegeneration could be ameliorated. VEGF-A165b prevented VEGF-A165a and hyperglycaemia-induced tight junction (TJ) breakdown and subsequent increase in solute flux in RPE cells. In streptozotocin (STZ)-induced diabetes, there was an increase in Evans Blue extravasation after both 1 and 8 weeks of diabetes, which was reduced upon intravitreal and systemic delivery of recombinant human (rh)VEGF-A165b. Eight-week diabetic rats also showed an increase in retinal vessel density, which was prevented by VEGF-A165b. These results show rhVEGF-A165b reduces DR-associated blood–retina barrier (BRB) dysfunction, angiogenesis and neurodegeneration and may be a suitable therapeutic in treating DR.
Collapse
|
28
|
Mechanisms regulating angiogenesis underlie seasonal control of pituitary function. Proc Natl Acad Sci U S A 2017; 114:E2514-E2523. [PMID: 28270617 DOI: 10.1073/pnas.1618917114] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Seasonal changes in mammalian physiology, such as those affecting reproduction, hibernation, and metabolism, are controlled by pituitary hormones released in response to annual environmental changes. In temperate zones, the primary environmental cue driving seasonal reproductive cycles is the change in day length (i.e., photoperiod), encoded by the pattern of melatonin secretion from the pineal gland. However, although reproduction relies on hypothalamic gonadotrophin-releasing hormone output, and most cells producing reproductive hormones are in the pars distalis (PD) of the pituitary, melatonin receptors are localized in the pars tuberalis (PT), a physically and functionally separate part of the gland. How melatonin in the PT controls the PD is not understood. Here we show that melatonin time-dependently acts on its receptors in the PT to alter splicing of vascular endothelial growth factor (VEGF). Outside the breeding season (BS), angiogenic VEGF-A stimulates vessel growth in the infundibulum, aiding vascular communication among the PT, PD, and brain. This also acts on VEGF receptor 2 (VEGFR2) expressed in PD prolactin-producing cells known to impair gonadotrophin secretion. In contrast, in the BS, melatonin releases antiangiogenic VEGF-Axxxb from the PT, inhibiting infundibular angiogenesis and diminishing lactotroph (LT) VEGFR2 expression, lifting reproductive axis repression in response to shorter day lengths. The time-dependent, melatonin-induced differential expression of VEGF-A isoforms culminates in alterations in gonadotroph function opposite to those of LTs, with up-regulation and down-regulation of gonadotrophin gene expression during the breeding and nonbreeding seasons, respectively. These results provide a mechanism by which melatonin can control pituitary function in a seasonal manner.
Collapse
|
29
|
Qin B, Liu J, Liu S, Li B, Ren J. MiR-20b targets AKT3 and modulates vascular endothelial growth factor-mediated changes in diabetic retinopathy. Acta Biochim Biophys Sin (Shanghai) 2016; 48:732-40. [PMID: 27421659 DOI: 10.1093/abbs/gmw065] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 05/26/2016] [Indexed: 12/17/2022] Open
Abstract
Diabetic retinopathy (DR) is the leading cause of new-onset blindness. The roles of microRNAs in diabetic retinopathy are largely unknown. The aim of this study is to investigate the role of miR-20b in DR. Transfection of miR-20b mimic in high glucose (HG)-treated human retinal endothelial cells (HRECs) increased miR-20b expression and decreased the expression level of VEGF mRNA, while transfection of miR-20b inhibitor in control HRECs reduced the miR-20b expression with a corresponding increase of VEGF mRNA. In vitro functional assay showed that transfection of miR-20b mimic prevented HG-induced increase in transendothelial permeability and tube formation in HRECs. Transfection of miR-20b inhibitor or treatment of VEGF increased transendothelial permeability and tube formation in control HRECs. Luciferase reported assay showed that AKT3 is a target of miR-20b. Transfection of miR-20b mimic prevented the up-regulation of AKT3 induced by HG without changing the protein levels of other isoforms of AKT, and silencing of AKT3 caused decrease of VEGF mRNA and protein levels as well as prevented HG-induced increase in transendothelial permeability and tube formation. Finally, we showed that miR-20b was down-regulated in the retina and retinal endothelial cells in diabetic rats, with a correlated up-regulation of VEGF and AKT3. Intravitreal injection of miR-20b mimic in the diabetic rat significantly increased the miR-20b expression and decreased the expression levels of AKT3 and VEGF in the retina tissues, and intravitreal delivery of AKT3 siRNA in the diabetic rat significantly decreased the expressions of AKT3 and VEGF. Collectively, miR-20b is important for the regulation of VEGF-mediated changes in HRECs and rat retinal tissues under hyperglycemic conditions possibly via targeting AKT3.
Collapse
Affiliation(s)
- Bo Qin
- Shenzhen Eye Hospital, Affiliated Shenzhen Eye Hospital of Jinan University, Joint College of Optometry, Shenzhen University, Shenzhen Key Laboratory of Ophthalmology, Shenzhen 518040, China
| | - Jinwen Liu
- Shenzhen Eye Hospital, Affiliated Shenzhen Eye Hospital of Jinan University, Joint College of Optometry, Shenzhen University, Shenzhen Key Laboratory of Ophthalmology, Shenzhen 518040, China
| | - Shenwen Liu
- Shenzhen Eye Hospital, Affiliated Shenzhen Eye Hospital of Jinan University, Joint College of Optometry, Shenzhen University, Shenzhen Key Laboratory of Ophthalmology, Shenzhen 518040, China
| | - Baijun Li
- Shenzhen Eye Hospital, Affiliated Shenzhen Eye Hospital of Jinan University, Joint College of Optometry, Shenzhen University, Shenzhen Key Laboratory of Ophthalmology, Shenzhen 518040, China
| | - Jing Ren
- Shenzhen Eye Hospital, Affiliated Shenzhen Eye Hospital of Jinan University, Joint College of Optometry, Shenzhen University, Shenzhen Key Laboratory of Ophthalmology, Shenzhen 518040, China
| |
Collapse
|
30
|
Wang H. Anti-VEGF therapy in the management of retinopathy of prematurity: what we learn from representative animal models of oxygen-induced retinopathy. Eye Brain 2016; 8:81-90. [PMID: 28539803 PMCID: PMC5398744 DOI: 10.2147/eb.s94449] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Retinopathy of prematurity (ROP) remains a leading cause of childhood blindness, affecting infants born prematurely. ROP is characterized by the onset of delayed physiological retinal vascular development (PRVD) and followed by pathologic neovascularization into the vitreous instead of the retina, called intravitreal neovascularization (IVNV). Therefore, the therapeutic strategy for treating ROP is to promote PRVD and inhibit or prevent IVNV. Vascular endothelial growth factor (VEGF) plays an important role in the pathogenesis of ROP. There is a growing body of studies testing the use of anti-VEGF agents as a treatment for ROP. Intravitreal anti-VEGF treatment for ROP has potential advantages compared with laser photocoagulation, the gold standard for the treatment of severe ROP; however, intravitreal anti-VEGF treatment has been associated with reactivation of ROP and suppression of systemic VEGF that may affect body growth and organ development in preterm infants. Therefore, it is important to understand the role of VEGF in PRVD and IVNV. This review includes the current knowledge of anti-VEGF treatment for ROP from animal models of oxygen-induced retinopathy (OIR), highlighting the importance of VEGF inhibition by targeting retinal Müller cells, which inhibits IVNV and permits PRVD. The signaling events involved in mediating VEGF expression and promoting VEGF-mediated angiogenesis, including hypoxia-dependent signaling, erythropoietin/erythropoietin receptor-, oxidative stress-, beta-adrenergic receptor-, integrin-, Notch/Delta-like ligand 4- and exon guidance molecules-mediated signaling pathways, are also discussed.
Collapse
Affiliation(s)
- Haibo Wang
- Department of Ophthalmology, John A Moran Eye Center, The University of Utah, Salt Lake City, UT, USA
| |
Collapse
|
31
|
Zhao M, Xie WK, Bai YJ, Huang LZ, Wang B, Liang JH, Yin H, Li XX, Shi X. Expression of Total Vascular Endothelial Growth Factor and the Anti-angiogenic VEGF 165 b Isoform in the Vitreous of Patients with Retinopathy of Prematurity. Chin Med J (Engl) 2016; 128:2505-9. [PMID: 26365970 PMCID: PMC4725572 DOI: 10.4103/0366-6999.164937] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background: This study was to examine the expression of total vascular endothelial growth factor (VEGF) and the anti-angiogenic VEGF165b isoform in the vitreous body of retinopathy of prematurity (ROP) patients, and to further study the role of the VEGF splicing in the development of ROP. Methods: This was a prospective clinical laboratory investigation study. All patients enrolled received standard ophthalmic examination with stage 4 ROP that required vitrectomy to collect the vitreous samples. The control samples were from congenital cataract patients. The expression of total VEGF and the anti-angiogenic VEGF165b were measured by enzyme-linked immunosorbent assay. Results were analyzed statistically using nonparametric tests. Results: The total VEGF level was markedly elevated in ROP samples while VEGF165b was markedly decreased compared to control group. The relative protein expression level of VEGF165b isoform was significantly decreased in ROP patients which were correlated with the ischemia-induced neovascularization. Conclusions: There was a switch of VEGF splicing from anti-angiogenic to pro-angiogenic family in ROP patients. A specific inhibitor that more selectively targets VEGF165and controls the VEGF splicing between pro- and anti-angiogenic families might be a more effective therapy for ROP.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Xuan Shi
- Department of Ophthalmology, Peking University People's Hospital, Beijing 100044; Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing 100044; Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing 100044, China
| |
Collapse
|
32
|
Amadio M, Govoni S, Pascale A. Targeting VEGF in eye neovascularization: What's new? Pharmacol Res 2016; 103:253-69. [DOI: 10.1016/j.phrs.2015.11.027] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 11/19/2015] [Accepted: 11/30/2015] [Indexed: 10/22/2022]
|
33
|
Lim DK, Wylie RG, Langer R, Kohane DS. Selective binding of C-6 OH sulfated hyaluronic acid to the angiogenic isoform of VEGF(165). Biomaterials 2016; 77:130-138. [PMID: 26588795 PMCID: PMC4735037 DOI: 10.1016/j.biomaterials.2015.10.074] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 10/26/2015] [Accepted: 10/29/2015] [Indexed: 01/17/2023]
Abstract
Vascular endothelial growth factor 165 (VEGF165) is an important extracellular protein involved in pathological angiogenesis in diseases such as cancer, wet age-related macular degeneration (wet-AMD) and retinitis pigmentosa. VEGF165 exists in two different isoforms: the angiogenic VEGF165a, and the anti-angiogenic VEGF165b. In some angiogenic diseases the proportion of VEGF165b may be equal to or higher than that of VEGF165a. Therefore, developing therapeutics that inhibit VEGF165a and not VEGF165b may result in greater anti-angiogenic activity and therapeutic benefit. To this end, we report the selective binding properties of sulfated hyaluronic acid (s-HA). Selective biopolymers offer several advantages over antibodies or aptamers including cost effective and simple synthesis, and the ability to make nanoparticles or hydrogels for drug delivery applications or VEGF165a sequestration. Limiting sulfation to the C-6 hydroxyl (C-6 OH) in the N-acetyl-glucosamine repeat unit of hyaluronic acid (HA) resulted in a polymer with strong affinity for VEGF165a but not VEGF165b. Increased sulfation beyond the C-6 OH (i.e. greater than 1 sulfate group per HA repeat unit) resulted in s-HA polymers that bound both VEGF165a and VEGF165b. The C-6 OH sulfated HA (Mw 150 kDa) showed strong binding properties to VEGF165a with a fast association rate constant (Ka; 2.8 × 10(6) M(-1) s(-1)), slow dissociation rate constant (Kd; 2.8 × 10(-3) s(-1)) and strong equilibrium binding constant (KD; ∼1.0 nM)), which is comparable to the non-selective VEGF165 binding properties of the commercialized therapeutic anti-VEGF antibody (Avastin(®)). The C-6 OH sulfated HA also inhibited human umbilical vein endothelial cell (HUVEC) survival and proliferation and human dermal microvascular endothelial cell (HMVEC) tube formation. These results demonstrate that the semi-synthetic natural polymer, C-6 OH sulfated HA, may be a promising biomaterial for the treatment of angiogenesis-related disease.
Collapse
Affiliation(s)
- Dong-Kwon Lim
- KU-KIST Graduate School of Converging Science and Technology, Korea University, 145 Anam-ro, Seongbuk gu, Seoul, South Korea
- Laboratory for Biomaterials and Drug Delivery, Department of Anesthesiology, Division of Critical Care Medicine, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts 02115, United States
| | - Ryan G. Wylie
- Department of Chemistry and Chemical Biology, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8S 4M1, Canada
- Laboratory for Biomaterials and Drug Delivery, Department of Anesthesiology, Division of Critical Care Medicine, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts 02115, United States
| | - Robert Langer
- David H. Koch Institutes for Integrative Cancer Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Daniel S. Kohane
- Laboratory for Biomaterials and Drug Delivery, Department of Anesthesiology, Division of Critical Care Medicine, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts 02115, United States
| |
Collapse
|
34
|
Cyclic thrombospondin-1 mimetics: grafting of a thrombospondin sequence into circular disulfide-rich frameworks to inhibit endothelial cell migration. Biosci Rep 2015; 35:BSR20150210. [PMID: 26464514 PMCID: PMC4660582 DOI: 10.1042/bsr20150210] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/12/2015] [Indexed: 12/22/2022] Open
Abstract
The findings suggest re-engineered cyclic TSP-1 mimetics are non-toxic, highly stable, and possess potent anti-angiogenesis activity without altering the native fold of the cyclic frameworks. This provides an alternative approach for cancer drug development particularly in the thrombospondin field. Tumour formation is dependent on nutrient and oxygen supply from adjacent blood vessels. Angiogenesis inhibitors can play a vital role in controlling blood vessel formation and consequently tumour progression by inhibiting endothelial cell proliferation, sprouting and migration. The primary aim of the present study was to design cyclic thrombospondin-1 (TSP-1) mimetics using disulfide-rich frameworks for anti-angiogenesis therapies and to determine whether these peptides have better potency than the linear parent peptide. A short anti-angiogenic heptapeptide fragment from TSP-1 (GVITRIR) was incorporated into two cyclic disulfide-rich frameworks, namely MCoTI-II (Momordica cochinchinensis trypsin inhibitor-II) and SFTI-1 (sunflower trypsin inhibitor-1). The cyclic peptides were chemically synthesized and folded in oxidation buffers, before being tested in a series of in vitro evaluations. Incorporation of the bioactive heptapeptide fragment into the cyclic frameworks resulted in peptides that inhibited microvascular endothelial cell migration, and had no toxicity against normal primary human endothelial cells or cancer cells. Importantly, all of the designed cyclic TSP-1 mimetics were far more stable than the linear heptapeptide in human serum. The present study has demonstrated a novel approach to stabilize the active region of TSP-1. The anti-angiogenic activity of the native TSP-1 active fragment was maintained in the new TSP-1 mimetics and the results provide a new chemical approach for the design of TSP-1 mimetics.
Collapse
|
35
|
Haque R, Hur EH, Farrell AN, Iuvone PM, Howell JC. MicroRNA-152 represses VEGF and TGFβ1 expressions through post-transcriptional inhibition of (Pro)renin receptor in human retinal endothelial cells. Mol Vis 2015; 21:224-35. [PMID: 25802486 PMCID: PMC4358229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 03/05/2015] [Indexed: 11/01/2022] Open
Abstract
PURPOSE The (pro)renin receptor (PRR), a component of the renin-angiotensin system (RAS), plays an important role in the physiologic and pathophysiological regulation of blood pressure and fluid/electrolyte homeostasis. The RAS including the PRR has been identified in retinal endothelial cells and other ocular tissues. In this study, the potential involvement of miRNAs in the posttranscriptional regulation of PRR was investigated in human retinal endothelial cells (hRECs) under high glucose (HG) conditions. METHODS miRNA-152 (miR-152) was identified in silico as a potential regulator of PRR, and this was confirmed by quantitative real-time PCR (qRT-PCR) and PRR 3'-untranslated region (UTR) reporter assays. Using RNA interference, both AT1R and PRR were implicated in the HG-mediated induction of vascular endothelial growth factor (VEGF), VEGF receptor 2 (VEGFR-2), and transforming growth factor β1 (TGFβ1). RESULTS The downregulation of miR-152 was observed in hRECs and rat retinal tissues under HG conditions. In parallel, PRR (target of miR-152), VEGF, VEGFR-2, and TGFβ1 at mRNA levels were elevated. However, the transfection of hRECs with miR-152 mimics in HG conditions resulted in the suppression of the PRR expression, as well as reduced VEGF, VEGFR-2, and TGFβ1 production. This was reversed by transfecting cells with the antisense (antagomir) of miR-152, suggesting the glucose-induced upregulation of VEGF, VEGFR-2, and TGFβ1 is mediated through PRR, and this regulation is likely achieved through the HG-mediated modulation of miRNAs. CONCLUSIONS We have demonstrated that miR-152 interacting with PRR regulates downstream VEGF, VRGFR-2, and TGFβ1 expressions in hRECs in HG conditions. These studies suggest miR-152 and PRR may play a role in the pathogenesis of diabetic retinopathy (DR).
Collapse
|
36
|
Oltean S, Qiu Y, Ferguson JK, Stevens M, Neal C, Russell A, Kaura A, Arkill KP, Harris K, Symonds C, Lacey K, Wijeyaratne L, Gammons M, Wylie E, Hulse RP, Alsop C, Cope G, Damodaran G, Betteridge KB, Ramnath R, Satchell SC, Foster RR, Ballmer-Hofer K, Donaldson LF, Barratt J, Baelde HJ, Harper SJ, Bates DO, Salmon AHJ. Vascular Endothelial Growth Factor-A165b Is Protective and Restores Endothelial Glycocalyx in Diabetic Nephropathy. J Am Soc Nephrol 2014; 26:1889-904. [PMID: 25542969 DOI: 10.1681/asn.2014040350] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 10/15/2014] [Indexed: 01/11/2023] Open
Abstract
Diabetic nephropathy is the leading cause of ESRD in high-income countries and a growing problem across the world. Vascular endothelial growth factor-A (VEGF-A) is thought to be a critical mediator of vascular dysfunction in diabetic nephropathy, yet VEGF-A knockout and overexpression of angiogenic VEGF-A isoforms each worsen diabetic nephropathy. We examined the vasculoprotective effects of the VEGF-A isoform VEGF-A165b in diabetic nephropathy. Renal expression of VEGF-A165b mRNA was upregulated in diabetic individuals with well preserved kidney function, but not in those with progressive disease. Reproducing this VEGF-A165b upregulation in mouse podocytes in vivo prevented functional and histologic abnormalities in diabetic nephropathy. Biweekly systemic injections of recombinant human VEGF-A165b reduced features of diabetic nephropathy when initiated during early or advanced nephropathy in a model of type 1 diabetes and when initiated during early nephropathy in a model of type 2 diabetes. VEGF-A165b normalized glomerular permeability through phosphorylation of VEGF receptor 2 in glomerular endothelial cells, and reversed diabetes-induced damage to the glomerular endothelial glycocalyx. VEGF-A165b also improved the permeability function of isolated diabetic human glomeruli. These results show that VEGF-A165b acts via the endothelium to protect blood vessels and ameliorate diabetic nephropathy.
Collapse
Affiliation(s)
| | - Yan Qiu
- School of Physiology and Pharmacology and
| | | | | | - Chris Neal
- School of Physiology and Pharmacology and
| | | | - Amit Kaura
- School of Physiology and Pharmacology and
| | | | | | | | | | | | | | - Emma Wylie
- School of Physiology and Pharmacology and Academic Renal Unit, School of Clinical Science, University of Bristol, Bristol, United Kingdom
| | | | | | - George Cope
- Academic Renal Unit, School of Clinical Science, University of Bristol, Bristol, United Kingdom
| | | | | | - Raina Ramnath
- Academic Renal Unit, School of Clinical Science, University of Bristol, Bristol, United Kingdom
| | - Simon C Satchell
- Academic Renal Unit, School of Clinical Science, University of Bristol, Bristol, United Kingdom
| | - Rebecca R Foster
- Academic Renal Unit, School of Clinical Science, University of Bristol, Bristol, United Kingdom
| | - Kurt Ballmer-Hofer
- Biomolecular Research, Molecular Cell Biology, Paul Scherrer Institut, Villigen, Switzerland
| | - Lucy F Donaldson
- School of Physiology and Pharmacology and School of Life Sciences and
| | - Jonathan Barratt
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and
| | - Hans J Baelde
- Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands
| | | | - David O Bates
- Cancer Biology, Division of Oncology, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Andrew H J Salmon
- School of Physiology and Pharmacology and Academic Renal Unit, School of Clinical Science, University of Bristol, Bristol, United Kingdom;
| |
Collapse
|
37
|
Affiliation(s)
- Howard Leong-Poi
- From the Division of Cardiology, Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital, University of Toronto, Toronto, Canada.
| |
Collapse
|
38
|
Bills VL, Hamdollah-Zadeh M, Soothill PW, Harper SJ, Bates DO. The role of VEGF-A165b in trophoblast survival. BMC Pregnancy Childbirth 2014; 14:278. [PMID: 25128406 PMCID: PMC4143552 DOI: 10.1186/1471-2393-14-278] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 07/09/2014] [Indexed: 12/31/2022] Open
Abstract
Background Pre-eclampsia remains a dominant cause of maternal and fetal mortality in developed countries. In a previous prospective study we identified a fall in the VEGF-A isoform VEGF-A165b in the plasma of patients in the first trimester to be a predictor of later pre-eclampsia. VEGF-A165b has been shown to have potent cytoprotective properties in many cell types. We therefore tested the hypothesis that VEGF-A165b may be cytoprotective for placental trophoblasts. Methods We used an immortalised first trimester trophoblast cell line exposed to chemical toxicity, and physiological (<2% O2) and atmospheric oxygen (21% O2) in the presence or absence of VEGF-A165b, angiogenic VEGF-A165a, a non-specific anti-VEGF-A blocking antibody (bevacizumab), or a specific anti-VEGF-A165b antibody. Cell viability and cytotoxicity were measured by trypan blue and LDH assay respectively. Results Under high (21%) levels of oxygen, trophoblast viability was increased, and cytotoxicity reduced by exogenous recombinant VEGF-A165b (p < 0.05, n = 10) or VEGF-A165a. The cytoprotective effect was not seen under lower (<2%) oxygen conditions, where VEGF-A165b was upregulated. However inhibition of VEGF-A with blocking antibodies (bevacizumab or anti-VEGF-A165b) had marked cytotoxic effects under low oxygen conditions presumably through the blockade of autocrine survival pathways. Conclusions These results show that when trophoblasts are exposed to lower oxygen tensions (as they are early in the 1st trimester) endogenous VEGF-A165b contributes to their survival through an autocrine pathway. In contrast in high oxygen conditions exogenous VEGF-A isoforms have a greater effect on trophoblast survival.
Collapse
Affiliation(s)
| | | | | | | | - David O Bates
- Cancer Biology, Division of Oncology, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7QT, UK.
| |
Collapse
|
39
|
Ngo DTM, Farb MG, Kikuchi R, Karki S, Tiwari S, Bigornia SJ, Bates DO, LaValley MP, Hamburg NM, Vita JA, Hess DT, Walsh K, Gokce N. Antiangiogenic actions of vascular endothelial growth factor-A165b, an inhibitory isoform of vascular endothelial growth factor-A, in human obesity. Circulation 2014; 130:1072-80. [PMID: 25116954 DOI: 10.1161/circulationaha.113.008171] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Experimental studies suggest that visceral adiposity and adipose tissue dysfunction play a central role in obesity-related cardiometabolic complications. Impaired angiogenesis in fat has been implicated in the development of adipose tissue hypoxia, capillary rarefaction, inflammation, and metabolic dysregulation, but pathophysiological mechanisms remain unknown. In this study, we examined the role of a novel antiangiogenic isoform of vascular endothelial growth factor-A (VEGF-A), VEGF-A165b, in human obesity. METHODS AND RESULTS We biopsied paired subcutaneous and visceral adipose tissue in 40 obese subjects (body mass index, 45±8 kg/m(2); age, 45±11 years) during bariatric surgery and characterized depot-specific adipose tissue angiogenic capacity using an established ex vivo assay. Visceral adipose tissue exhibited significantly blunted angiogenic growth compared with subcutaneous fat (P<0.001) that was associated with marked tissue upregulation of VEGF-A165b (P=0.004). The extent of VEGF-A165b expression correlated negatively with angiogenic growth (r=-0.6, P=0.006). Although recombinant VEGF-A165b significantly impaired angiogenesis, targeted inhibition of VEGF-A165b with neutralizing antibody stimulated fat pad neovascularization and restored VEGF receptor activation. Blood levels of VEGF-A165b were significantly higher in obese subjects compared with lean control subjects (P=0.02), and surgical weight loss induced a marked decline in serumVEGF-A165b (P=0.003). CONCLUSIONS We demonstrate that impaired adipose tissue angiogenesis is associated with overexpression of a novel antiangiogenic factor, VEGF-A165b, that may play a pathogenic role in human adiposopathy. Moreover, systemic upregulation of VEGF-A165b in circulating blood may have wider-ranging implications beyond the adipose milieu. VEGF-A165b may represent a novel area of investigation to gain further understanding of mechanisms that modulate the cardiometabolic consequences of obesity.
Collapse
Affiliation(s)
- Doan T M Ngo
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Melissa G Farb
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Ryosuke Kikuchi
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Shakun Karki
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Stephanie Tiwari
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Sherman J Bigornia
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - David O Bates
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Michael P LaValley
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Naomi M Hamburg
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Joseph A Vita
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Donald T Hess
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Kenneth Walsh
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Noyan Gokce
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.).
| |
Collapse
|
40
|
Angiogenesis in multiple sclerosis and experimental autoimmune encephalomyelitis. Acta Neuropathol Commun 2014; 2:84. [PMID: 25047180 PMCID: PMC4149233 DOI: 10.1186/s40478-014-0084-z] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/09/2014] [Indexed: 02/07/2023] Open
Abstract
Angiogenesis, the formation of new vessels, is found in Multiple Sclerosis (MS) demyelinating lesions following Vascular Endothelial Growth Factor (VEGF) release and the production of several other angiogenic molecules. The increased energy demand of inflammatory cuffs and damaged neural cells explains the strong angiogenic response in plaques and surrounding white matter. An angiogenic response has also been documented in an experimental model of MS, experimental allergic encephalomyelitis (EAE), where blood–brain barrier disruption and vascular remodelling appeared in a pre-symptomatic disease phase. In both MS and EAE, VEGF acts as a pro-inflammatory factor in the early phase but its reduced responsivity in the late phase can disrupt neuroregenerative attempts, since VEGF naturally enhances neuron resistance to injury and regulates neural progenitor proliferation, migration, differentiation and oligodendrocyte precursor cell (OPC) survival and migration to demyelinated lesions. Angiogenesis, neurogenesis and oligodendroglia maturation are closely intertwined in the neurovascular niches of the subventricular zone, one of the preferential locations of inflammatory lesions in MS, and in all the other temporary vascular niches where the mutual fostering of angiogenesis and OPC maturation occurs. Angiogenesis, induced either by CNS inflammation or by hypoxic stimuli related to neurovascular uncoupling, appears to be ineffective in chronic MS due to a counterbalancing effect of vasoconstrictive mechanisms determined by the reduced axonal activity, astrocyte dysfunction, microglia secretion of free radical species and mitochondrial abnormalities. Thus, angiogenesis, that supplies several trophic factors, should be promoted in therapeutic neuroregeneration efforts to combat the progressive, degenerative phase of MS.
Collapse
|
41
|
Gammons MV, Lucas R, Dean R, Coupland SE, Oltean S, Bates DO. Targeting SRPK1 to control VEGF-mediated tumour angiogenesis in metastatic melanoma. Br J Cancer 2014; 111:477-85. [PMID: 25010863 PMCID: PMC4119992 DOI: 10.1038/bjc.2014.342] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 04/23/2014] [Accepted: 05/01/2014] [Indexed: 01/06/2023] Open
Abstract
Background: Current therapies for metastatic melanoma are targeted either at cancer mutations driving growth (e.g., vemurafenib) or immune-based therapies (e.g., ipilimumab). Tumour progression also requires angiogenesis, which is regulated by VEGF-A, itself alternatively spliced to form two families of isoforms, pro- and anti-angiogenic. Metastatic melanoma is associated with a splicing switch to pro-angiogenic VEGF-A, previously shown to be regulated by SRSF1 phosphorylation by SRPK1. Here, we show a novel approach to preventing angiogenesis—targeting splicing factor kinases that are highly expressed in melanomas. Methods: We used RT–PCR, western blotting and immunohistochemistry to investigate SRPK1, SRSF1 and VEGF expression in tumour cells, and in vivo xenograft assays to investigate SRPK1 knockdown and inhibition in vivo. Results: In both uveal and cutaneous melanoma cell lines, SRPK1 was highly expressed, and inhibition of SRPK1 by knockdown or with pharmacological inhibitors reduced pro-angiogenic VEGF expression maintaining the production of anti-angiogenic VEGF isoforms. Both pharmacological SRPK1 inhibitors and SRPK1 knockdown reduced growth of human melanomas in vivo, but neither affected cell proliferation in vitro. Conclusions: These results suggest that selective blocking of pro-angiogenic isoforms by inhibiting splice-site selection with SRPK1 inhibitors reduces melanoma growth. SRPK1 inhibitors may be used as therapeutic agents.
Collapse
Affiliation(s)
- M V Gammons
- Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - R Lucas
- Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - R Dean
- Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - S E Coupland
- Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool, UK
| | - S Oltean
- Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - D O Bates
- 1] Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK [2] Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK
| |
Collapse
|
42
|
Thichanpiang P, Harper SJ, Wongprasert K, Bates DO. TNF-α-induced ICAM-1 expression and monocyte adhesion in human RPE cells is mediated in part through autocrine VEGF stimulation. Mol Vis 2014; 20:781-9. [PMID: 24940033 PMCID: PMC4057247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 06/07/2014] [Indexed: 11/22/2022] Open
Abstract
PURPOSE Local inflammation at the RPE cell layer is associated with inflammatory cell migration and secretion of proinflammatory cytokines such as tumor necrosis factor (TNF)-α. TNF-α upregulates intercellular adhesion molecule (ICAM)-1 expression on the RPE, which allows lymphocyte function-associated antigen-1 (LFA-1) to bind on leukocytes that contribute to leukocyte adhesion at sites of inflammation. Vascular endothelial growth factor (VEGF)-A(165)b is generated by alternative splicing of VEGF-A in the terminal exon, exon 8. VEGF-A(165)b is cytoprotective and antiangiogenic, but its effects on inflammation have not yet been elucidated. Therefore, we tested the hypothesis that VEGF-A(165)b regulates TNF-α-induced ICAM-1 expression and monocyte adhesion in RPE cells. METHODS Primary RPE cells were pretreated with TNF-α alone, VEGF-A(165)b alone, VEGF-A(165)b with anti-VEGF-A(165)b, or the VEGFR-2 inhibitor ZM323881 before exposure to TNF-α for 24 h. Western blotting and monocyte adhesion assays were performed. RESULTS VEGF-A(165)b and ZM323881 inhibited TNF-α-induced upregulation of ICAM-1 in RPE cells. The effect of VEGF-A(165)b was neutralized by an antibody to VEGF-A(165)b. VEGF-A(165)b ameliorated TNF-α-induced monocyte-RPE adhesion. CONCLUSIONS These findings indicate that VEGF-A(165)b inhibits TNF-α-mediated upregulation of ICAM-1 expression and increases monocyte-RPE cell adhesion, suggesting an anti-inflammatory property of VEGF-A(165)b in the eye.
Collapse
Affiliation(s)
- Peeradech Thichanpiang
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, Thailand,Microvascular Research Laboratories, Department of Physiology and Pharmacology, School of Veterinary Sciences, University of Bristol, Bristol, UK
| | - Steven J. Harper
- Microvascular Research Laboratories, Department of Physiology and Pharmacology, School of Veterinary Sciences, University of Bristol, Bristol, UK
| | - Kanokpan Wongprasert
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - David O. Bates
- Microvascular Research Laboratories, Department of Physiology and Pharmacology, School of Veterinary Sciences, University of Bristol, Bristol, UK,Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, UK
| |
Collapse
|
43
|
Simó R, Sundstrom JM, Antonetti DA. Ocular Anti-VEGF therapy for diabetic retinopathy: the role of VEGF in the pathogenesis of diabetic retinopathy. Diabetes Care 2014; 37:893-9. [PMID: 24652720 DOI: 10.2337/dc13-2002] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Diabetic retinopathy is the leading cause of visual impairment and preventable blindness, and represents a significant socioeconomic cost for health care systems worldwide. Therefore, new approaches beyond current standards of diabetes care are needed. Based on the crucial pathogenic role of vascular endothelial growth factor (VEGF) in the development of diabetic macular edema (DME), intravitreal anti-VEGF agents have emerged as new treatments. To provide an understanding of the rationale for use and clinical efficacy of anti-VEGF treatment, we examine this topic in a two-part Bench to Clinic narrative. In the Bench narrative, we provide an overview of the role of VEGF in the pathogenesis of diabetic retinopathy, the molecular characteristics of anti-VEGF agents currently used, and future perspectives and challenges in this area. In the Clinic narrative that follows our contribution, Cheung et al. provide an overview of the current evidence from clinical trials on anti-VEGF therapy for diabetic retinopathy.
Collapse
|
44
|
Trophic factors in the pathogenesis and therapy for retinal degenerative diseases. Surv Ophthalmol 2014; 59:134-65. [PMID: 24417953 DOI: 10.1016/j.survophthal.2013.09.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 09/11/2013] [Accepted: 09/17/2013] [Indexed: 12/27/2022]
Abstract
Trophic factors are endogenously secreted proteins that act in an autocrine and/or paracrine fashion to affect vital cellular processes such as proliferation, differentiation, and regeneration, thereby maintaining overall cell homeostasis. In the eye, the major contributors of these molecules are the retinal pigment epithelial (RPE) and Müller cells. The primary paracrine targets of these secreted proteins include the photoreceptors and choriocapillaris. Retinal degenerative diseases such as age-related macular degeneration and retinitis pigmentosa are characterized by aberrant function and/or eventual death of RPE cells, photoreceptors, choriocapillaris, and other retinal cells. We discuss results of in vitro and in vivo animal studies in which candidate trophic factors, either singly or in combination, were used in an attempt to ameliorate photoreceptor and/or retinal degeneration. We also examine current trophic factor therapies as they relate to the treatment of retinal degenerative diseases in clinical studies.
Collapse
|
45
|
Gammons MV, Fedorov O, Ivison D, Du C, Clark T, Hopkins C, Hagiwara M, Dick AD, Cox R, Harper SJ, Hancox JC, Knapp S, Bates DO. Topical antiangiogenic SRPK1 inhibitors reduce choroidal neovascularization in rodent models of exudative AMD. Invest Ophthalmol Vis Sci 2013; 54:6052-62. [PMID: 23887803 PMCID: PMC3771558 DOI: 10.1167/iovs.13-12422] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 07/18/2013] [Indexed: 12/14/2022] Open
Abstract
PURPOSE Exudative AMD (wet AMD) is treated by monthly injection into the eye of anti-VEGF proteins. VEGF is alternatively spliced to produce numerous isoforms that differ in angiogenic activity. Serine-rich protein kinase-1 (SRPK1) has been identified as a regulator of pro-angiogenic VEGF splicing by phosphorylating serine-rich splicing factor-1 (SRSF1), which binds to VEGF pre-mRNA. We tested the hypothesis that topical (eye drop) SRPK1-selective inhibitors could be generated that reduce pro-angiogenic isoforms, and prevent choroidal neovascularization in vivo. METHODS Novel inhibitors were tested for SRPK inhibition in vitro, pro-angiogenic VEGF production in RPE cells by PCR and ELISA, and for inhibition of choroidal neovascularisation in mice and rats. RESULTS A novel disubstituted furan inhibitor was selective for the SRPK family of kinases and reduced expression of pro-angiogenic but not antiangiogenic VEGF isoforms. This inhibitor and previously identified SRPK inhibitors significantly reduced choroidal neovascularisation in vivo. Topical administration of SRPK inhibitors dose-dependently blocked CNV with an EC50 of 9 μM. CONCLUSIONS These results indicate that novel SRPK1 selective inhibitors could be a potentially novel topical (eye drop) therapeutic for wet AMD.
Collapse
Affiliation(s)
- Melissa V. Gammons
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - Oleg Fedorov
- Nuffield Department of Clinical Medicine, Structural Genomics Consortium and Target Discovery Institute (TDI), University of Oxford, Oxford, United Kingdom
| | - David Ivison
- School of Chemistry, University of Bristol, Bristol, United Kingdom
| | - Chunyun Du
- Cardiovascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - Tamsyn Clark
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - Claire Hopkins
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - Masatoshi Hagiwara
- Department of Anatomy and Developmental Biology Graduate School of Medicine, Kyoto University, Japan
| | - Andrew D. Dick
- School of Clinical Sciences and School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
| | - Russell Cox
- School of Chemistry, University of Bristol, Bristol, United Kingdom
| | - Steven J. Harper
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - Jules C. Hancox
- Cardiovascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - Stefan Knapp
- Nuffield Department of Clinical Medicine, Structural Genomics Consortium and Target Discovery Institute (TDI), University of Oxford, Oxford, United Kingdom
| | - David O. Bates
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
- Cancer Biology, Division of Oncology, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| |
Collapse
|
46
|
Gammons MVR, Dick AD, Harper SJ, Bates DO. SRPK1 inhibition modulates VEGF splicing to reduce pathological neovascularization in a rat model of retinopathy of prematurity. Invest Ophthalmol Vis Sci 2013; 54:5797-806. [PMID: 23761094 DOI: 10.1167/iovs.13-11634] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE We tested the hypothesis that recombinant human VEGF-A165b and the serine arginine protein kinase (SRPK) inhibitor, SRPIN340, which controls splicing of the VEGF-A pre-mRNA, prevent neovascularization in a rodent model of retinopathy of prematurity (ROP). METHODS In the 50/10 oxygen-induced retinopathy (50/10 OIR) model that exposes newborn rats to repeated cycles of 24 hours of 50% oxygen alternating with 24 hours of 10% oxygen, pups received intraocular injections of SRPIN340, vehicle, VEGF165b, anti-VEGF antibody, or saline. Whole mounts of retinas were prepared for isolectin immunohistochemistry, and preretinal or intravitreal neovascularization (PRNV) determined by clock hour analysis. RESULTS The anti-VEGF antibody (P < 0.04), rhVEGF165b (P < 0.001), and SRPIN340 (P < 0.05) significantly reduced PRNV compared with control eyes. SRPIN340 reduced the expression of proangiogenic VEGF165 without affecting VEGF165b expression. CONCLUSIONS These results suggest that splicing regulation through selective downregulation of proangiogenic VEGF isoforms (via SRPK1 inhibition) or competitive inhibition of VEGF signaling by rhVEGF165b has the potential to be an effective alternative to potential cyto- and neurotoxic anti-VEGF agents in the treatment of pathological neovascularization in the eye.
Collapse
Affiliation(s)
- Melissa V R Gammons
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Bristol, UK
| | | | | | | |
Collapse
|
47
|
Beazley-Long N, Hua J, Jehle T, Hulse RP, Dersch R, Lehrling C, Bevan H, Qiu Y, Lagrèze WA, Wynick D, Churchill AJ, Kehoe P, Harper SJ, Bates DO, Donaldson LF. VEGF-A165b is an endogenous neuroprotective splice isoform of vascular endothelial growth factor A in vivo and in vitro. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 183:918-29. [PMID: 23838428 DOI: 10.1016/j.ajpath.2013.05.031] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 05/19/2013] [Accepted: 05/31/2013] [Indexed: 01/13/2023]
Abstract
Vascular endothelial growth factor (VEGF) A is generated as two isoform families by alternative RNA splicing, represented by VEGF-A165a and VEGF-A165b. These isoforms have opposing actions on vascular permeability, angiogenesis, and vasodilatation. The proangiogenic VEGF-A165a isoform is neuroprotective in hippocampal, dorsal root ganglia, and retinal neurons, but its propermeability, vasodilatatory, and angiogenic properties limit its therapeutic usefulness. In contrast, a neuroprotective effect of endogenous VEGF-A165b on neurons would be advantageous for neurodegenerative pathologies. Endogenous expression of human and rat VEGF-A165b was detected in hippocampal and cortical neurons. VEGF-A165b formed a significant proportion of total VEGF-A in rat brain. Recombinant human VEGF-A165b exerted neuroprotective effects in response to multiple insults, including glutamatergic excitotoxicity in hippocampal neurons, chemotherapy-induced cytotoxicity of dorsal root ganglion neurons, and retinal ganglion cells (RGCs) in rat retinal ischemia-reperfusion injury in vivo. Neuroprotection was dependent on VEGFR2 and MEK1/2 activation but not on p38 or phosphatidylinositol 3-kinase activation. Recombinant human VEGF-A165b is a neuroprotective agent that effectively protects both peripheral and central neurons in vivo and in vitro through VEGFR2, MEK1/2, and inhibition of caspase-3 induction. VEGF-A165b may be therapeutically useful for pathologies that involve neuronal damage, including hippocampal neurodegeneration, glaucoma diabetic retinopathy, and peripheral neuropathy. The endogenous nature of VEGF-A165b expression suggests that non-isoform-specific inhibition of VEGF-A (for antiangiogenic reasons) may be damaging to retinal and sensory neurons.
Collapse
Affiliation(s)
- Nicholas Beazley-Long
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Antiangiogenic VEGF isoform in inflammatory myopathies. Mediators Inflamm 2013; 2013:219313. [PMID: 23840094 PMCID: PMC3694558 DOI: 10.1155/2013/219313] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 05/01/2013] [Accepted: 05/15/2013] [Indexed: 11/18/2022] Open
Abstract
Objective. To investigate expression of vascular endothelial growth factor (VEGF) antiangiogenic isoform A-165b on human muscle in idiopathic inflammatory myopathies (IIM) and to compare distribution of angiogenic/antiangiogenic VEGFs, as isoforms shifts are described in other autoimmune disorders. Subjects and Methods. We analyzed VEGF-A165b and VEGF-A by western blot and immunohistochemistry on skeletal muscle biopsies from 21 patients affected with IIM (polymyositis, dermatomyositis, and inclusion body myositis) and 6 control muscle samples. TGF-β, a prominent VEGF inductor, was analogously evaluated. Intergroup differences of western blot bands density were statistically examined. Endomysial vascularization, inflammatory score, and muscle regeneration, as pathological parameters of IIM, were quantitatively determined and their levels were confronted with VEGF expression. Results. VEGF-A165b was significantly upregulated in IIM, as well as TGF-β. VEGF-A was diffusely expressed on unaffected myofibers, whereas regenerating/atrophic myofibres strongly reacted for both VEGF-A isoforms. Most inflammatory cells and endomysial vessels expressed both isoforms. VEGF-A165b levels were in positive correlation to inflammatory score, endomysial vascularization, and TGF-β. Conclusions. Our findings indicate skeletal muscle expression of antiangiogenic VEGF-A165b and preferential upregulation in IIM, suggesting that modulation of VEGF-A isoforms may occur in myositides.
Collapse
|
49
|
Delcombel R, Janssen L, Vassy R, Gammons M, Haddad O, Richard B, Letourneur D, Bates D, Hendricks C, Waltenberger J, Starzec A, Sounni NE, Noël A, Deroanne C, Lambert C, Colige A. New prospects in the roles of the C-terminal domains of VEGF-A and their cooperation for ligand binding, cellular signaling and vessels formation. Angiogenesis 2012; 16:353-71. [PMID: 23254820 DOI: 10.1007/s10456-012-9320-y] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 10/26/2012] [Indexed: 01/13/2023]
Abstract
VEGF-A is a crucial growth factor for blood vessel homeostasis and pathological angiogenesis. Due to alternative splicing of its pre-mRNA, VEGF-A is produced under several isoforms characterized by the combination of their C-terminal domains, which determines their respective structure, availability and affinity for co-receptors. As controversies still exist about the specific roles of these exon-encoded domains, we systematically compared the properties of eight natural and artificial variants containing the domains encoded by exons 1-4 and various combinations of the domains encoded by exons 5, 7 and 8a or 8b. All the variants (VEGF111a, VEGF111b, VEGF121a, VEGF121b, VEGF155a, VEGF155b, VEGF165a, VEGF165b) have a similar affinity for VEGF-R2, as determined by Surface plasmon resonance analyses. They strongly differ however in terms of binding to neuropilin-1 and heparin/heparan sulfate proteoglycans. Data indicate that the 6 amino acids encoded by exon 8a must be present and cooperate with those of exons 5 or 7 for efficient binding, which was confirmed in cell culture models. We further showed that VEGF165b has inhibitory effects in vitro, as previously reported, but that the shortest VEGF variant possessing also the 6 amino acids encoded by exon 8b (VEGF111b) is remarkably proangiogenic, demonstrating the critical importance of domain interactions for defining the VEGF properties. The number, size and localization of newly formed blood vessels in a model of tumour angiogenesis strongly depend also on the C-terminal domain composition, suggesting that association of several VEGF isoforms may be more efficient for treating ischemic diseases than the use of any single variant.
Collapse
Affiliation(s)
- Romain Delcombel
- Laboratory of Connective Tissues Biology, GIGA-R, University of Liège, Avenue de l'Hôpital 3, 4000, Liège, Belgium.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Bates DO, Catalano PJ, Symonds KE, Varey AHR, Ramani P, O'Dwyer PJ, Giantonio BJ, Meropol NJ, Benson AB, Harper SJ. Association between VEGF splice isoforms and progression-free survival in metastatic colorectal cancer patients treated with bevacizumab. Clin Cancer Res 2012; 18:6384-91. [PMID: 23104894 DOI: 10.1158/1078-0432.ccr-12-2223] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Bevacizumab improves survival for patients with metastatic colorectal cancer with chemotherapy, but no proven predictive markers exist. The VEGF-A splice form, VEGF(165)b, anti-angiogenic in animal models, binds bevacizumab. We tested the hypothesis that prolonged progression-free survival (PFS) would occur only in patients with low relative VEGF(165)b levels treated with bevacizumab. EXPERIMENTAL DESIGN Blinded tumor samples from the phase III trial of FOLFOX4 ± bevacizumab were assessed for VEGF(165)b and VEGF(total) by immunohistochemistry and scored relative to normal tissue. A predictive index (PI) was derived from the ratio of VEGF(165)b:VEGF(total) for 44 samples from patients treated with FOLFOX + bevacizumab (arm A) and 53 samples from patients treated with FOLFOX4 (arm B), and PFS, and overall survival (OS) analyzed on the basis of PI relative to median ratio. RESULTS Unadjusted analysis of PFS showed significantly better outcome for individuals with VEGF(165)b:VEGF(total) ratio scores below median treated with FOLFOX4 + bevacizumab compared with FOLFOX4 alone (median, 8.0 vs. 5.2 months; P < 0.02), but no effect of bevacizumab on PFS in patients with VEGF(165)b:VEGF(total) ratio >median (5.9 vs. 6.3 months). These findings held after adjustment for other clinical and demographic features. OS was increased in arm A (median, 13.6 months) compared with arm B (10.6 months) in the low VEGF(165)b group, but this did not reach statistical significance. There was no difference in the high VEGF(165)b:VEGF(total) group between FOLFOX + bevacizumab (10.8 months) and FOLFOX alone (11.3 months). CONCLUSION Low VEGF(165)b:VEGF(total) ratio may be a predictive marker for bevacizumab in metastatic colorectal cancer, and individuals with high relative levels may not benefit.
Collapse
Affiliation(s)
- David O Bates
- Microvascular Research Laboratories, Department of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom.
| | | | | | | | | | | | | | | | | | | |
Collapse
|