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Abstract
The cornea in most species is physiologically avascular, and thus this assay allows the measurement of newly formed vessels. The continuous monitoring of neovascular growth in the same animal allows the evaluation of drugs acting as suppressors or stimulators of angiogenesis. Under anesthesia a micropocket is produced in the cornea thickness and the angiogenesis stimulus (tumor tissue, cell suspension, growth factor) is placed into the pocket in order to induce vascular outgrowth from the limbal capillaries. Neovascular development and progression can be modified by the presence of locally released or applied inhibitory factors or by systemic treatments. In this chapter the experimental details of the avascular cornea assay, the technical challenges, and advantages and disadvantages in different species are discussed. Protocols for local drug treatment and tissue sampling for histology and pharmacokinetic profile are reported.
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Affiliation(s)
- Marina Ziche
- Department of Life Sciences, University of Siena, Siena, Italy,
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252
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Uehara H, Mamalis C, McFadden M, Taggart M, Stagg B, Passi S, Earle P, Chakravarthy U, Hogg RE, Ambati BK. The reduction of serum soluble Flt-1 in patients with neovascular age-related macular degeneration. Am J Ophthalmol 2015; 159:92-100.e1-2. [PMID: 25284761 PMCID: PMC4262635 DOI: 10.1016/j.ajo.2014.09.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 09/22/2014] [Accepted: 09/23/2014] [Indexed: 12/29/2022]
Abstract
PURPOSE To evaluate serum soluble Flt-1 (sFlt-1) in age-related macular degeneration (AMD) patients. DESIGN Case-control study. METHODS Study involved 56 non-AMD participants, 53 early AMD patients, and 97 neovascular AMD patients from Belfast in Northern Ireland. Serum samples were collected from each patient. Serum sFlt-1 was measured by human sVEGFR1/sFlt-1 ELISA kit. The results were analyzed by Excel and SPSS. RESULTS Serum sFlt-1 concentration of non-AMD, early AMD, and neovascular AMD were 90.8 ± 2.9 pg/mL (± standard error of the mean), 88.2 ± 2.6 pg/mL, and 79.9 ± 2.2 pg/mL. sFlt-1 from neovascular AMD patients was significantly decreased compared to non-AMD and early AMD patients (ANOVA, P < .01). For each 10-point increase in sFlt-1, the odds for having neovascular AMD compared with non-AMD and neovascular AMD decrease by 27.8%, odds ratio (OR) = 0.722 (95% confidence interval [CI]: 0.588-0.888, P = .002) and 27.0%, OR = 0.730 (95% CI: 0.594-0.898, P = .003), respectively. In patients over 73 years of age, serum sFlt-1 <80 pg/mL was associated with a >6-fold higher risk of neovascular AMD. CONCLUSIONS Reduced serum sFlt-1 differentiates those patients with neovascular AMD from both early AMD and non-AMD participants. In those aged over 73, serum sFlt <80 pg/mL seems to indicate a particularly high risk of neovascular AMD. Our results indicate serum sFlt-1 could be a biomarker for development of neovascular AMD.
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Affiliation(s)
- Hironori Uehara
- John A Moran Eye Center, University of Utah, Salt Lake City, Utah
| | | | - Molly McFadden
- Division of Epidemiology, University of Utah, Salt Lake City, Utah
| | - Michael Taggart
- John A Moran Eye Center, University of Utah, Salt Lake City, Utah
| | - Brian Stagg
- John A Moran Eye Center, University of Utah, Salt Lake City, Utah
| | - Samuel Passi
- John A Moran Eye Center, University of Utah, Salt Lake City, Utah
| | - Phillip Earle
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Usha Chakravarthy
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Ruth E Hogg
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
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253
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Ronquillo CC, Passi SF, Ambati BK. Restoring Physiologic Barriers Against Neovascular Invasion. ESSENTIALS IN OPHTHALMOLOGY 2015. [DOI: 10.1007/978-3-662-45188-5_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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254
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Antilymphangiogenic therapy to promote transplant survival and to reduce cancer metastasis: what can we learn from the eye? Semin Cell Dev Biol 2014; 38:117-30. [PMID: 25460541 DOI: 10.1016/j.semcdb.2014.11.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 10/01/2014] [Accepted: 11/12/2014] [Indexed: 12/22/2022]
Abstract
The lymphatic vasculature is - amongst other tasks - essentially involved in inflammation, (auto)immunity, graft rejection and cancer metastasis. The eye is mainly devoid of lymphatic vessels except for its adnexa, the conjunctiva and the limbus. However, several pathologic conditions can result in the secondary ingrowth of lymphatic vessels into physiologically alymphatic parts of the eye such as the cornea or the inner eye. Therefore, the cornea has served as an excellent in vivo model system to study lymphangiogenesis, and findings from such studies have substantially contributed to the understanding of central principles of lymphangiogenesis also with relevance outside the eye. Grafting experiments at the cornea have been extensively used to analyze the role of lymphangiogenesis in transplant immunology. In this regard, we recently demonstrated the crucial role of lymphatic vessels in mediating corneal allograft rejection and could show that antilymphangiogenic therapy increases graft survival. In the field of cancer research, we recently detected tumor-associated lymphangiogenesis in the most common malignant tumors of the eye, such as conjunctival carcinoma and melanoma, and ciliochoroidal melanoma with extraocular extension. These neolymphatics correlate with an increased risk of local recurrence, metastasis and tumor related death, and may offer potential therapeutic targets for the treatment of these tumors. This review will focus on corneal and tumor-associated ocular lymphangiogenesis. First, we will describe common experimentally used corneal lymphangiogenesis models and will recapitulate recent findings regarding the involvement of lymphatic vessels in corneal diseases and transplant immunology. The second part of this article will summarize findings about the participation of tumor-associated lymphangiogenesis in ocular malignancies and their implications for the development of future therapeutic strategies.
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255
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Fan X, Rai A, Kambham N, Sung JF, Singh N, Petitt M, Dhal S, Agrawal R, Sutton RE, Druzin ML, Gambhir SS, Ambati BK, Cross JC, Nayak NR. Endometrial VEGF induces placental sFLT1 and leads to pregnancy complications. J Clin Invest 2014; 124:4941-52. [PMID: 25329693 DOI: 10.1172/jci76864] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 08/21/2014] [Indexed: 12/27/2022] Open
Abstract
There is strong evidence that overproduction of soluble fms-like tyrosine kinase-1 (sFLT1) in the placenta is a major cause of vascular dysfunction in preeclampsia through sFLT1-dependent antagonism of VEGF. However, the cause of placental sFLT1 upregulation is not known. Here we demonstrated that in women with preeclampsia, sFLT1 is upregulated in placental trophoblasts, while VEGF is upregulated in adjacent maternal decidual cells. In response to VEGF, expression of sFlt1 mRNA, but not full-length Flt1 mRNA, increased in cultured murine trophoblast stem cells. We developed a method for transgene expression specifically in mouse endometrium and found that endometrial-specific VEGF overexpression induced placental sFLT1 production and elevated sFLT1 levels in maternal serum. This led to pregnancy losses, placental vascular defects, and preeclampsia-like symptoms, including hypertension, proteinuria, and glomerular endotheliosis in the mother. Knockdown of placental sFlt1 with a trophoblast-specific transgene caused placental vascular changes that were consistent with excess VEGF activity. Moreover, sFlt1 knockdown in VEGF-overexpressing animals enhanced symptoms produced by VEGF overexpression alone. These findings indicate that sFLT1 plays an essential role in maintaining vascular integrity in the placenta by sequestering excess maternal VEGF and suggest that a local increase in VEGF can trigger placental overexpression of sFLT1, potentially contributing to the development of preeclampsia and other pregnancy complications.
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256
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Tumor necrosis factor alpha and interleukin-6 facilitate corneal lymphangiogenesis in response to herpes simplex virus 1 infection. J Virol 2014; 88:14451-7. [PMID: 25297992 DOI: 10.1128/jvi.01841-14] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED Herpes simplex virus 1 (HSV-1) is a common human pathogen of clinical significance due to its association with vision impairment and encephalitis. In a mouse model of ocular neovascularization, we have previously shown that HSV-1 elicits the genesis of lymphatic vessels into the cornea proper through epithelial cell expression of vascular endothelial growth factor A (VEGFA) dependent upon expression of VEGFR2 during acute infection. We hypothesized that other factors may be involved in lymphangiogenesis, with proinflammatory cytokines as the leading candidates. In the absence of infection or inflammation, intrastromal administration of tumor necrosis factor alpha (TNF-α) coupled with VEGFA elicited lymphatic vessel genesis significantly above either factor alone as well as a vehicle control. Consistent with this observation, anti-TNF-α antibody (Ab) blocked HSV-1-mediated corneal lymphangiogenesis within the first 5 days postinfection. However, TNF-α-deficient (TNF-α(-/-)) mice displayed a level of corneal vessel growth similar to that shown by wild-type (WT) controls. To investigate the likely redundant nature of cytokines, PCR array analysis of HSV-1-infected TNF-α(-/-) mice was conducted, and it revealed several factors elevated above those found in HSV-1-infected WT mice, including interleukin-1β (IL-1β), platelet-derived growth factor, angiopoietin 2, insulin-like growth factor 2, and IL-6. Subconjunctival administration of neutralizing Ab to IL-6 blocked lymphangiogenesis in TNF-α(-/-) mice. Whereas the cornea levels of IL-6 were significantly reduced, there was no appreciable change in the level of IL-1β or other proangiogenic factors analyzed. Collectively, the results suggest in addition to VEGFA, TNF-α and IL-6 promote and likely synergize with VEGFA in corneal lymphangiogenesis during acute HSV-1 infection. IMPORTANCE We have identified at least two proinflammatory cytokines expressed locally that are involved in the genesis of lymphatic vessels in the normally avascular cornea in response to HSV-1 infection. This finding provides the basis to target IL-6 and TNF-α as additional proangiogenic factors in the cornea during the development of herpetic stromal keratitis as a means to alleviate further neovascularization and tissue pathology associated with the host immune response to the pathogen.
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257
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Torricelli AAM, Wilson SE. Cellular and extracellular matrix modulation of corneal stromal opacity. Exp Eye Res 2014; 129:151-60. [PMID: 25281830 DOI: 10.1016/j.exer.2014.09.013] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 08/08/2014] [Accepted: 09/30/2014] [Indexed: 01/23/2023]
Abstract
Stromal transparency is a critical factor contributing to normal function of the visual system. Corneal injury, surgery, disease and infection elicit complex wound healing responses that serve to protect against insults and maintain the integrity of the cornea, and subsequently to restore corneal structure and transparency. However, in some cases these processes result in prolonged loss of corneal transparency and resulting diminished vision. Corneal opacity is mediated by the complex actions of many cytokines, growth factors, and chemokines produced by the epithelial cells, stromal cells, bone marrow-derived cells, lacrimal tissues, and nerves. Myofibroblasts, and the disorganized extracellular matrix produced by these cells, are critical determinants of the level and persistence of stromal opacity after corneal injury. Decreases in corneal crystallins in myofibroblasts and corneal fibroblasts contribute to cellular opacity in the stroma. Regeneration of a fully functional epithelial basement membrane (BM) appears to have a critical role in the maintenance of corneal stromal transparency after mild injuries and recovery of transparency when opacity is generated after severe injuries. The epithelial BM likely has a regulatory function whereby it modulates epithelium-derived growth factors such as transforming growth factor (TGF) β and platelet-derived growth factor (PDGF) that drive the development and persistence of myofibroblasts from precursor cells. The purpose of this article is to review the factors involved in the maintenance of corneal transparency and to highlight the mechanisms involved in the appearance, persistency and regression of corneal opacity after stromal injury.
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Abstract
PURPOSE To report a case of marginal keratitis that developed after intravitreal ranibizumab injection. METHODS A 56-year-old man with diffuse diabetic macular edema received intravitreal injection of ranibizumab into his right eye. RESULTS One day after injection, the patient presented with pain, redness, tearing, and discomfort in his right eye. Anterior segment examination of the right eye revealed subconjunctival hemorrhage, 3 corneal subepithelial peripheral infiltrates separated from the limbus by a clear zone, and mild anterior chamber reaction. Examination of the eyelids was remarkable for mild blepharitis. Fungal and bacterial cultures were negative. The condition resolved with topical corticosteroids and antibiotics. CONCLUSIONS Intravitreal ranibizumab injection may trigger hypersensitivity reaction in the form of marginal keratitis in patients with mild blepharitis.
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259
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Ortega I, Sefat F, Deshpande P, Paterson T, Ramachandran C, Ryan AJ, MacNeil S, Claeyssens F. Combination of microstereolithography and electrospinning to produce membranes equipped with niches for corneal regeneration. J Vis Exp 2014:51826. [PMID: 25285843 PMCID: PMC4828067 DOI: 10.3791/51826] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Corneal problems affect millions of people worldwide reducing their quality of life significantly. Corneal disease can be caused by illnesses such as Aniridia or Steven Johnson Syndrome as well as by external factors such as chemical burns or radiation. Current treatments are (i) the use of corneal grafts and (ii) the use of stem cell expanded in the laboratory and delivered on carriers (e.g., amniotic membrane); these treatments are relatively successful but unfortunately they can fail after 3-5 years. There is a need to design and manufacture new corneal biomaterial devices able to mimic in detail the physiological environment where stem cells reside in the cornea. Limbal stem cells are located in the limbus (circular area between cornea and sclera) in specific niches known as the Palisades of Vogt. In this work we have developed a new platform technology which combines two cutting-edge manufacturing techniques (microstereolithography and electrospinning) for the fabrication of corneal membranes that mimic to a certain extent the limbus. Our membranes contain artificial micropockets which aim to provide cells with protection as the Palisades of Vogt do in the eye.
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Affiliation(s)
- Ilida Ortega
- Department of Materials Science and Engineering, University of Sheffield;
| | - Farshid Sefat
- Department of Materials Science and Engineering, University of Sheffield
| | - Pallavi Deshpande
- Department of Materials Science and Engineering, University of Sheffield
| | - Thomas Paterson
- Department of Materials Science and Engineering, University of Sheffield
| | | | | | - Sheila MacNeil
- Department of Materials Science and Engineering, University of Sheffield
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260
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Swamynathan S, Swamynathan SK. SLURP-1 modulates corneal homeostasis by serving as a soluble scavenger of urokinase-type plasminogen activator. Invest Ophthalmol Vis Sci 2014; 55:6251-61. [PMID: 25168896 DOI: 10.1167/iovs.14-15107] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Our previous study revealed the immunomodulatory property of the secreted lymphocyte antigen (Ly6)/urokinase-type plasminogen activator receptor (uPAR)-related protein-1 (SLURP1), abundantly expressed in the cornea and associated with the hyperkeratotic disorder Mal de Meleda. Here, we test the hypothesis that SLURP1 modulates the functions of membrane-tethered uPAR by acting as a soluble scavenger of its ligand urokinase-type plasminogen activator (uPA). METHODS Human corneal limbal epithelial (HCLE) and mouse corneal stromal fibroblast MK/T-1 cells were employed to examine the effect of SLURP1 on cell proliferation and migration. Human corneal limbal epithelial cell clones stably expressing SLURP1 under the control of cytomegalovirus (CMV) promoter were generated using lentiviral vectors. Recombinant 6× His-mouse Slurp1 and maltose-binding protein (MBP)-mouse uPA were expressed in Escherichia coli and partially purified using nickel-ion and amylose columns, respectively. Slurp1 interaction with uPA was detected using ligand blots, ELISA, pull-down assays, and immunofluorescent staining. RESULTS Stable expression of SLURP1 in HCLE cells was confirmed by immunoblots and immunofluorescent staining. Human corneal limbal epithelial and MK/T-1 cell proliferation and migration rates were suppressed by exogenous SLURP1. Ligand blots, ELISA, and pull-down assays indicated that Slurp1 efficiently interacts with uPA. Immunofluorescent staining demonstrated that exogenous SLURP1 decreased the amount of cell surface-bound uPA in the leading edges of migrating cells. In gap-filling assays, wild-type HCLE cells responded to uPA by increasing their velocity and closing larger area, while the SLURP1-expressing HCLE cells failed to do so. CONCLUSIONS SLURP1 modulates corneal homeostasis by serving as a soluble scavenger of uPA and regulating the uPA-dependent functions of uPAR.
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Affiliation(s)
- Sudha Swamynathan
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Shivalingappa K Swamynathan
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
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261
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Kyadari M, Fatma T, Azad R, Velpandian T. Evaluation of antiangiogenic and antiproliferative potential of the organic extract of green algae Chlorella pyrenoidosa. Indian J Pharmacol 2014; 45:569-74. [PMID: 24347763 PMCID: PMC3847245 DOI: 10.4103/0253-7613.121366] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Revised: 12/28/2012] [Accepted: 09/15/2013] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE algae isolates obtained from fresh and marine resources could be one of the richest sources of novel bioactive secondary metabolites expected to have pharmaceutical significance for new drug development. This study was conducted to evaluate the antiangiogenic and antiproliferative activity of Chlorella pyrenoidosa in experimental models of angiogenesis and by MTT assay. MATERIALS AND METHODS lyophilized extract of C. pyrenoidosa was extracted using dichloromethane/methanol (2:1), concentrated and vacuum evaporated to obtain the dried extract. The crude extract was evaluated in the vascular endothelial growth factor (VEGF)-induced angiogenesis in in ovo chick chorioallantoic membrane assay (CAM) at various concentrations (n = 8) using thalidomide and normal saline as positive and untreated control groups, respectively. The crude extract was also subjected to the antiangiogenic activity in the silver nitrate/potassium nitrate cautery model of corneal neovascularization (CN) in rats where topical bevacizumab was used as a positive control. The vasculature was photographed and blood vessel density was quantified using Aphelion imaging software. The extract was also evaluated for its anti proliferative activity by microculture tetrazolium test (MTT) assay using HeLa cancer cell line (ATCC). RESULTS VEGF increased the blood vessel density by 220% as compared to normal and thalidomide treatment decreased it to 67.2% in in ovo assay. In the in-vivo CN model, the mean neovascular density in the control group, the C. pyrenoidosa extract and bevacizumab group were found to be 100%, 59.02%, and 32.20%, respectively. The Chlorella pyrenoidosa extract negatively affected the viability of HeLa cells. An IC50 value of the extract was 570 μg/ml, respectively. CONCLUSION a significant antiangiogenic activity was observed against VEGF-induced neovascularization and antiproliferative activity by MTT assay. In this study, it could be attributed that the activity may be due to the presence of secondary metabolites in the C. pyrenoidosa extract.
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Affiliation(s)
- Mahender Kyadari
- Department of Pharmacy, Integrated Institute of Technology, Dwarka, New Delhi, India
| | - Tasneem Fatma
- Department of Bio-Sciences, Jamia Millia Islamia, New Delhi, India
| | - Rajvardhan Azad
- Department of Ocular Pharmacology and Pharmacy, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Thirumurthy Velpandian
- Department of Ocular Pharmacology and Pharmacy, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
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262
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Simultaneous study of matrix metalloproteinases, proinflammatory cytokines, and soluble cytokine receptors in the tears of noninfectious corneal ulcer patients. Graefes Arch Clin Exp Ophthalmol 2014; 252:1451-6. [PMID: 25005620 DOI: 10.1007/s00417-014-2708-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 05/10/2014] [Accepted: 06/23/2014] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND We investigated the presence of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), proinflammatory cytokines, and soluble cytokine receptors in the tear fluid of patients with noninfectious corneal ulcers in the peripheral cornea. METHODS The subjects were 20 eyes of 17 patients with peripheral noninfectious corneal ulcers and 20 eyes of 20 volunteers. Tear samples were taken by the Schirmer test I method and the presence of MMPs (MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, MMP-10, and MMP-13) and TIMPs (TIMP-1, TIMP-2, and TIMP-4) were investigated using an MMP antibody array system. The concentrations of proinflammatory cytokines {IL-1β, IL-6, and TNF-α (tumor necrosis factor-alpha)} and soluble cytokine receptors {soluble (s) IL-1R1, sIL-1R2, sIL-2Rα, sIL-4R, sIL-6R, sTNFR1, sTNFR2, s-vascular endothelial growth factor receptor (VEGFR) 1, sVEGFR2, sVEGFR3, and sgp130} were determined using the multiplex bead immunoassay system. RESULTS The concentrations of MMP-8 and MMP-9 were significantly up-regulated in the tear fluid of the ulcer patients, whereas TIMPs concentrations did not change. The concentrations of IL-1β, IL-6, sIL-1R2, sIL-6R, sTNFR1, and sTNFR2 were up-regulated in the ulcer patients, whereas sgp130 and sVEGFR1 concentrations significantly decreased. CONCLUSIONS The presence of some MMPs increased significantly in the patients with peripheral noninfectious corneal ulcers, whereas the presence of TIMPs remained unchanged. Although some proinflammatory cytokines were up-regulated, their antagonists, soluble cytokine receptors, were also up-regulated. It is thus possible that the up-regulation of MMPs disrupts the balance between the MMPs and TIMPs and that this balance may play a pivotal role in the pathophysiology of corneal ulceration.
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Abstract
Vascular endothelial growth factor (VEGF)-VEGF receptor (VEGFR) system has been shown to play central roles not only in physiological angiogenesis, but also in pathological angiogenesis in diseases such as cancer. Based on these findings, a variety of anti-angiogenic drugs, including anti-VEGF antibodies and VEGFR/multi-receptor kinase inhibitors have been developed and approved for the clinical use. While the clinical efficacy of these drugs has been clearly demonstrated in cancer patients, they have not been shown to be effective in curing cancer, suggesting that further improvement in their design is necessary. Abnormal expression of an endogenous VEGF-inhibitor sFlt-1 has been shown to be involved in a variety of diseases, such as preeclampsia and aged macular degeneration. In addition, various factors modulating angiogenic processes have been recently isolated. Given this complexity then, extensive studies on the interrelationship between VEGF signals and other angiogenesis-regulatory systems will be important for developing future strategies to suppress diseases with an angiogenic component.
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Affiliation(s)
- Masabumi Shibuya
- Jobu University, Director, Institute of Physiology and Medicine, Gunma 372-8588 ; Tokyo Medical and Dental University, Department of Molecular Oncology, Tokyo 113-8519 ; University of Tokyo, Tokyo 108-8639, Japan
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Noma H, Mimura T, Yasuda K, Shimura M. Vascular endothelial growth factor and its soluble receptors-1 and -2 in iris neovascularization and neovascular glaucoma. Ophthalmologica 2014; 232:102-9. [PMID: 24942011 DOI: 10.1159/000360303] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 02/01/2014] [Indexed: 11/19/2022]
Abstract
Concentrations of vascular endothelial growth factor (VEGF), soluble VEGF receptor-1 (sVEGFR-1) and soluble VEGF receptor-2 (sVEGFR-2) were measured by enzyme-linked immunosorbent assay in 27 proliferative diabetic retinopathy patients who had iris neovascularization (INV) with or without neovascular glaucoma (NVG). The 27 eyes were divided into two groups, consisting of INV without elevation of the intraocular pressure (IOP; INV group) and INV with elevated IOP (NVG group). Ten patients with an idiopathic macular hole were used as the controls. The vitreous levels of VEGF, sVEGFR-1 and sVEGFR-2 showed a significant increase across the three groups. In the INV and NVG groups, the vitreous level of VEGF showed a significant correlation with the levels of sVEGFR-1 and sVEGFR-2. There was also a significant correlation between the vitreous levels of sVEGFR-1 and sVEGFR-2. These results suggest that the vitreous levels of sVEGFR-1 and sVEGFR-2 are dependent on VEGF in patients who have INV with or without NVG.
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Affiliation(s)
- Hidetaka Noma
- Department of Ophthalmology, Hachioji Medical Center, Tokyo Medical University, Tokyo, Japan
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265
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Abstract
Rheumatoid arthritis (RA), the most common autoimmune disorder associated with dry eye syndrome, is also associated with sight-threatening ocular diseases such as peripheral ulcerative keratitis, scleritis and corneal melts. Tissue damage on the ocular surface of patients with RA is autoimmune-mediated. Findings from patients with dry eye have implicated defects in innate immunity (Toll-like receptors, S100A and resident antigen-presenting cells), cytokines, chemokines and T helper (TH)-cell subsets (including TH1 and TH17) in disease pathogenesis. Some of these features are probably important in dry eye related to RA, which can occur at a different time from articular disease and is more clinically severe than idiopathic dry eye. Ocular surface immune factors can be influenced by the systemic immune landscape. Depending on the severity of ocular inflammation in RA, treatment can include ciclosporin, topical corticosteroids, tacrolimus, autologous serum and systemic immunosuppression. Tissue damage is treated by inhibiting matrix metalloproteinases. Potential therapeutic strategies benefit from an improved understanding of ocular surface immunology, and include targeting of T-cell subsets, B-cell signalling or cytokines.
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266
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Park PJ, Chang M, Garg N, Zhu J, Chang JH, Shukla D. Corneal lymphangiogenesis in herpetic stromal keratitis. Surv Ophthalmol 2014; 60:60-71. [PMID: 25444520 DOI: 10.1016/j.survophthal.2014.06.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 05/23/2014] [Accepted: 06/04/2014] [Indexed: 12/26/2022]
Abstract
Corneal lymphangiogenesis is the extension of lymphatic vessels into the normally alymphatic cornea, a process that compromises the cornea's immune-privileged state and facilitates herpetic stromal keratitis (HSK). HSK results most commonly from infection by herpes simplex virus-1 (HSV-1) and is characterized by immune- and inflammation-mediated damage to the deep layers of the cornea. Current research demonstrates the potential of anti-lymphangiogenic therapy to decrease and prevent herpes-induced lymphangiogenesis.
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Affiliation(s)
- Paul J Park
- Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Michael Chang
- Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Nitin Garg
- Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Jimmy Zhu
- Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA; Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Jin-Hong Chang
- Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA; Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Deepak Shukla
- Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA; Department Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA.
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267
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Dry Eye Predisposes to Corneal Neovascularization and Lymphangiogenesis After Corneal Injury in a Murine Model. Cornea 2014; 33:621-7. [DOI: 10.1097/ico.0000000000000107] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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268
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Matsumoto K, Ema M. Roles of VEGF-A signalling in development, regeneration, and tumours. J Biochem 2014; 156:1-10. [DOI: 10.1093/jb/mvu031] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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Sema3A maintains corneal avascularity during development by inhibiting Vegf induced angioblast migration. Dev Biol 2014; 391:241-50. [PMID: 24809797 DOI: 10.1016/j.ydbio.2014.04.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 04/14/2014] [Accepted: 04/23/2014] [Indexed: 12/25/2022]
Abstract
Corneal avascularity is important for optical clarity and normal vision. However, the molecular mechanisms that prevent angioblast migration and vascularization of the developing cornea are not clear. Previously we showed that periocular angioblasts and forming ocular blood vessels avoid the presumptive cornea despite dynamic ingression of neural crest cells. In the current study, we investigate the role of Semaphorin3A (Sema3A), a cell guidance chemorepellent, on angioblast migration and corneal avascularity during development. We show that Sema3A, Vegf, and Nrp1 are expressed in the anterior eye during cornea development. Sema3A mRNA transcripts are expressed at significantly higher levels than Vegf in the lens that is positioned adjacent to the presumptive cornea. Blockade of Sema3A signaling via lens removal or injection of a synthetic Sema3A inhibitor causes ectopic migration of angioblasts into the cornea and results in its subsequent vascularization. In addition, using bead implantation, we demonstrate that exogenous Sema3A protein inhibits Vegf-induced vascularization of the cornea. In agreement with these findings, loss of Sema/Nrp1 signaling in Nrp1(Sema-) mutant mice results in ectopic angioblasts and vascularization of the embryonic mouse corneas. Altogether, our results reveal Sema3A signaling as an important cue during the establishment of corneal avascularity in both chick and mouse embryos. Our study introduces cornea development as a new model for studying the mechanisms involved in vascular patterning during embryogenesis and it also provides new insights into therapeutic potential for Sema3A in neovascular diseases.
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270
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Abstract
Corneal wound healing is a complex process: its mechanisms and the underlying genetic control are not fully understood. It involves the integrated actions of multiple growth factors, cytokines and proteases produced by epithelial cells, stromal keratocytes, inflammatory cells and lacrimal gland cells. Following an epithelial insult, multiple cytokines are released triggering a cascade of events that leads to repair the epithelial defect and remodelling of the stroma to minimize the loss of transparency and function. In this review, we examine the literature surrounding the genomics of corneal wound healing with respect to the following topics: epithelial and stromal wound healing (including inhibition); corneal neovascularisation; the role of corneal nerves in wound healing; the endothelium; the role of aquaporins and aptamers. We also examine the effect of ectasia on corneal wound healing with regard to keratoconus and following corneal surgery. A better understanding of the cellular and molecular changes that occur during repair of corneal wounds will provide the opportunity to design treatments that selectively modulate key phases of the healing process resulting in scars that more closely resemble normal corneal architecture.
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Affiliation(s)
- Nick J R Maycock
- Eye Department, Queen Alexandra Hospital, Portsmouth, UKNational Institute for Health Research (NIHR), Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
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271
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Yuen D, Grimaldo S, Sessa R, Ecoiffier T, Truong T, Huang E, Bernas M, Daley S, Witte M, Chen L. Role of angiopoietin-2 in corneal lymphangiogenesis. Invest Ophthalmol Vis Sci 2014; 55:3320-7. [PMID: 24781940 PMCID: PMC4039380 DOI: 10.1167/iovs.13-13779] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 04/21/2014] [Indexed: 12/19/2022] Open
Abstract
PURPOSE Lymphatic research has progressed rapidly in recent years. Lymphatic dysfunction has been found in myriad disorders from cancer metastasis to transplant rejection; however, effective treatment for lymphatic disorders is still limited. This study investigates the role of angiopoietin-2 (Ang-2) in corneal inflammatory lymphangiogenesis (LG) in vivo and in lymphatic endothelial cell (LEC) functions in vitro. METHODS Standard suture placement model was used to study Ang-2 expression in inflamed cornea, and corneal LG and hemangiogenesis (HG) responses in Ang-2 knockout mice. Moreover, human LEC culture system was used to examine the effect of Ang-2 gene knockdown on LEC functions using small interfering RNAs (siRNAs). The effect of siRNA treatment on corneal LG was also assessed in vivo. RESULTS Angiopoietin-2 was expressed on lymphatic vessels and macrophages in inflamed cornea. While corneal LG response was abolished in Ang-2 knockout mice, the HG response was also significantly suppressed with disorganized patterning. Moreover, anti-Ang-2 treatment inhibited LEC proliferation and capillary tube formation in vitro and corneal LG in vivo. CONCLUSIONS Angiopoietin-2 is critically involved in lymphatic processes in vivo and in vitro. Further investigation of the Ang-2 pathway may provide novel insights and therapeutic strategies for lymphatic-related disorders, which occur both inside and outside the eye.
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Affiliation(s)
- Don Yuen
- Center for Eye Disease and Development, Program in Vision Science and School of Optometry, University of California, Berkeley, Berkeley, California, United States
| | - Sammy Grimaldo
- Center for Eye Disease and Development, Program in Vision Science and School of Optometry, University of California, Berkeley, Berkeley, California, United States
| | - Roberto Sessa
- Center for Eye Disease and Development, Program in Vision Science and School of Optometry, University of California, Berkeley, Berkeley, California, United States
| | - Tatiana Ecoiffier
- Center for Eye Disease and Development, Program in Vision Science and School of Optometry, University of California, Berkeley, Berkeley, California, United States
| | - Tan Truong
- Center for Eye Disease and Development, Program in Vision Science and School of Optometry, University of California, Berkeley, Berkeley, California, United States
- Graduate Group in Vision Science, University of California, Berkeley, Berkeley, California, United States
| | - Eric Huang
- Center for Eye Disease and Development, Program in Vision Science and School of Optometry, University of California, Berkeley, Berkeley, California, United States
| | - Michael Bernas
- Department of Surgery, School of Medicine, University of Arizona, Tucson, Arizona, United States
| | - Sarah Daley
- Department of Surgery, School of Medicine, University of Arizona, Tucson, Arizona, United States
| | - Marlys Witte
- Department of Surgery, School of Medicine, University of Arizona, Tucson, Arizona, United States
| | - Lu Chen
- Center for Eye Disease and Development, Program in Vision Science and School of Optometry, University of California, Berkeley, Berkeley, California, United States
- Graduate Group in Vision Science, University of California, Berkeley, Berkeley, California, United States
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272
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Anderson C, Zhou Q, Wang S. An alkali-burn injury model of corneal neovascularization in the mouse. J Vis Exp 2014. [PMID: 24748032 DOI: 10.3791/51159] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Under normal conditions, the cornea is avascular, and this transparency is essential for maintaining good visual acuity. Neovascularization (NV) of the cornea, which can be caused by trauma, keratoplasty or infectious disease, breaks down the so called 'angiogenic privilege' of the cornea and forms the basis of multiple visual pathologies that may even lead to blindness. Although there are several treatment options available, the fundamental medical need presented by corneal neovascular pathologies remains unmet. In order to develop safe, effective, and targeted therapies, a reliable model of corneal NV and pharmacological intervention is required. Here, we describe an alkali-burn injury corneal neovascularization model in the mouse. This protocol provides a method for the application of a controlled alkali-burn injury to the cornea, administration of a pharmacological compound of interest, and visualization of the result. This method could prove instrumental for studying the mechanisms and opportunities for intervention in corneal NV and other neovascular disorders.
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Affiliation(s)
| | | | - Shusheng Wang
- Department of Cell and Molecular Biology, Tulane University; Department of Ophthalmology, Tulane University;
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273
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Buttler K, Badar M, Seiffart V, Laggies S, Gross G, Wilting J, Weich HA. De novo hem- and lymphangiogenesis by endothelial progenitor and mesenchymal stem cells in immunocompetent mice. Cell Mol Life Sci 2014; 71:1513-27. [PMID: 23995988 PMCID: PMC11113513 DOI: 10.1007/s00018-013-1460-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 07/23/2013] [Accepted: 08/19/2013] [Indexed: 11/26/2022]
Abstract
Cellular pro-angiogenic therapies may be applicable for the treatment of peripheral vascular diseases. Interactions between mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs) may provide such a treatment option. With the exception of some studies in man, experiments have only been performed in immunodeficient mice and rats. We studied an immunocompetent syngeneic mouse model. We isolated MSCs from bone marrow and EPCs from the lung of adult C57/Bl.6 mice and co-injected them in Matrigel subcutaneously in adult C57/Bl.6 mice. We demonstrate development of both blood vessels and lymphatics. Grafted EPCs integrated into the lining of the two vessel types, whereas MSCs usually did not incorporate into the vessel wall. Injections of each separate cell type did not, or hardly, reveal de novo angiogenesis. The release of VEGF-A by MSCs has been shown before, but its inhibitors, e.g., soluble VEGF receptors, have not been studied. We performed qualitative and quantitative studies of the proteins released by EPCs, MSCs, and cocultures of the cells. Despite the secretion of VEGF inhibitors (sVEGFR-1, sVEGFR-2) by EPCs, VEGF-A was secreted by MSCs at bioavailable amounts (350 pg/ml). We confirm the secretion of PlGF, FGF-1, MCP-1, and PDGFs by EPCs/MSCs and suggest functions for VEGF-B, amphiregulin, fractalkine, CXCL10, and CXCL16 during MSC-induced hem- and lymphangiogenesis. We assume that lymphangiogenesis is induced indirectly by growth factors from immigrating leukocytes, which we found in close association with the lymphatic networks. Inflammatory responses to the cellular markers GFP and cell-tracker red (CMPTX) used for tracing of EPCs or MSCs were not observed. Our studies demonstrate the feasibility of pro-angiogenic/lymphangiogenic therapies in immunocompetent animals and indicate new MSC/EPC-derived angiogenic factors.
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Affiliation(s)
- Kerstin Buttler
- Department of Anatomy and Cell Biology, University Medicine Göttingen, Göttingen, Germany,
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274
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Treatment of Corneal Neovascularization Using Anti-VEGF Bevacizumab. J Ophthalmol 2014; 2014:178132. [PMID: 24778865 PMCID: PMC3981012 DOI: 10.1155/2014/178132] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Revised: 02/18/2014] [Accepted: 02/19/2014] [Indexed: 12/27/2022] Open
Abstract
Purpose. To evaluate antiangiogenic effect of local use of bevacizumab (anti-VEGF antibody) in patients with corneal neovascularization. Methods. Patients were divided into two groups. All patients suffered from some form of corneal neovascularization (NV). Patients in group A received 0.2–0.5 mL of bevacizumab solution subconjunctivally (concentration 25 mg/mL) in a single dose. Group A included 28 eyes from 27. Patients in group B applied bevacizumab eye drops twice daily (concentration 2.5 mg/mL) for two weeks. Group B included 38 eyes from 35 patients. We evaluated the number of corneal segments affected by NV, CDVA, and the incidence of complications and subjective complaints related to the treatment. The minimum follow-up period was six months. Results. By the 6-month follow-up, in group A the percentage reduction of the affected peripheral segments was 21.6% and of the central segments was 9.6%; in group B the percentage reduction of the central segments was 22.7% and of the central segments was 38.04%. In both groups we noticed a statistically significant reduction in the extent of NV. Conclusion. The use of bevacizumab seems to be an effective and safe method in the treatment of corneal neovascularization, either in the subconjunctival or topical application form.
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275
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Hernández V, Malafronte N, Mora F, Pesca MS, Aquino RP, Mencherini T. Antioxidant and antiangiogenic activity ofAstronium graveolensJacq. leaves. Nat Prod Res 2014; 28:917-22. [DOI: 10.1080/14786419.2014.889134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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276
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Di Marco GS, Pavenstädt H, Brand M. Soluble Flt-1 release response to heparin use: implications for dialysis patients? Nephrol Dial Transplant 2014; 29:1112-5. [PMID: 24578469 DOI: 10.1093/ndt/gfu043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
| | - Hermann Pavenstädt
- Department of Internal Medicine D, University Hospital Münster, Münster, Germany
| | - Marcus Brand
- Department of Internal Medicine D, University Hospital Münster, Münster, Germany
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277
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Rolfsen ML, Frisard NE, Stern EM, Foster TP, Bhattacharjee PS, McFerrin Jr HE, Clement C, Rodriguez PC, Lukiw WJ, Bergsma DR, Ochoa AC, Hill JM. Corneal neovascularization: a review of the molecular biology and current therapies. EXPERT REVIEW OF OPHTHALMOLOGY 2014. [DOI: 10.1586/eop.13.8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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278
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Soluble fms-like tyrosine kinase-1 and atherosclerosis in chronic kidney disease. Kidney Int 2014; 85:238-40. [DOI: 10.1038/ki.2013.402] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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279
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Siegfried G, Khatib AM. Processing of VEGF-C and -D by the Proprotein Convertases: Importance in Angiogenesis, Lymphangiogenesis, and Tumorigenesis. ACTA ACUST UNITED AC 2013. [DOI: 10.4199/c00097ed1v01y201310pac006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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280
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Vempati P, Popel AS, Mac Gabhann F. Extracellular regulation of VEGF: isoforms, proteolysis, and vascular patterning. Cytokine Growth Factor Rev 2013; 25:1-19. [PMID: 24332926 DOI: 10.1016/j.cytogfr.2013.11.002] [Citation(s) in RCA: 198] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/14/2013] [Accepted: 11/19/2013] [Indexed: 12/15/2022]
Abstract
The regulation of vascular endothelial growth factor A (VEGF) is critical to neovascularization in numerous tissues under physiological and pathological conditions. VEGF has multiple isoforms, created by alternative splicing or proteolytic cleavage, and characterized by different receptor-binding and matrix-binding properties. These isoforms are known to give rise to a spectrum of angiogenesis patterns marked by differences in branching, which has functional implications for tissues. In this review, we detail the extensive extracellular regulation of VEGF and the ability of VEGF to dictate the vascular phenotype. We explore the role of VEGF-releasing proteases and soluble carrier molecules on VEGF activity. While proteases such as MMP9 can 'release' matrix-bound VEGF and promote angiogenesis, for example as a key step in carcinogenesis, proteases can also suppress VEGF's angiogenic effects. We explore what dictates pro- or anti-angiogenic behavior. We also seek to understand the phenomenon of VEGF gradient formation. Strong VEGF gradients are thought to be due to decreased rates of diffusion from reversible matrix binding, however theoretical studies show that this scenario cannot give rise to lasting VEGF gradients in vivo. We propose that gradients are formed through degradation of sequestered VEGF. Finally, we review how different aspects of the VEGF signal, such as its concentration, gradient, matrix-binding, and NRP1-binding can differentially affect angiogenesis. We explore how this allows VEGF to regulate the formation of vascular networks across a spectrum of high to low branching densities, and from normal to pathological angiogenesis. A better understanding of the control of angiogenesis is necessary to improve upon limitations of current angiogenic therapies.
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Affiliation(s)
- Prakash Vempati
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Aleksander S Popel
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Feilim Mac Gabhann
- Institute for Computational Medicine and Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.
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281
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Chen GL, Zhang JJ, Zhao J, Wang DJ, Zhang H. Evaluation of corneal graft survival in mice model. Int J Ophthalmol 2013; 6:578-83. [PMID: 24195028 DOI: 10.3980/j.issn.2222-3959.2013.05.04] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 08/09/2013] [Indexed: 11/02/2022] Open
Abstract
AIM To investigate the characteristics and criterion of graft rejection in mice model. METHODS C57BL/6 or BALB/c mice corneal grafts were grafted onto BALB/c hosts. Each group was divided into two subgroups according to the corneal opacity scores 12d after transplantation. The characteristics of opacity and neovascularization were observed. Mice of the 12(th), 50(th) day after transplantation, the grafts biopsy of mice in allogeneic group 1, which opacity score exceed 3, were prepared for histological observation and those restore transparent were endothelial stained. RESULTS There was no difference of corneal opacity score on the 7(th) and 12(th) day after operation; the histological results had no disparity between syngeneic group and allogeneic group. On the 12(th) day after surgery, the turbidity curve was apparent in grafts with opacity score < 2. Mononuclear cells were shown in grafts with opacity score reached 3 in allogeneic group 1. Different rejection performance was observed in tissue sections on the 50(th) day after surgery. CONCLUSION Grafts, opacity score exceeds 3 from the 7(th) to the 12(th) day after operation could not be judged as a rejection. We should pay more attention to the variation of grafts opacity since 12d after corneal transplantation.
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Affiliation(s)
- Guo-Ling Chen
- Department of Ophthalmology, the Second Hospital of Shandong University, 247 Beiyuan Road, Jinan 250033, Shandong Province, China
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282
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Abstract
Vascular endothelial growth factor receptors (VEGFRs) in vertebrates play essential roles in the regulation of angiogenesis and lymphangiogenesis. VEGFRs belong to the receptor-type tyrosine kinase (RTK) supergene family. They consist of a ligand-binding region with seven immunoglobulin (7 Ig) -like domains, a trans-membrane (TM) domain, and a tyrosine kinase (TK) domain with a long kinase insert (KI) (also known as a type-V RTK). Structurally, VEGFRs are distantly related to the members of the M-colony stimulating factor receptor/platelet-derived growth factor receptor (CSFR)/(PDGFR) family, which have five immunoglobulin (5 Ig)-like domains. However, signal transduction in VEGFRs significantly differs from that in M-CSFR/PDGFRs. VEGFR2, the major signal transducer for angiogenesis, preferentially uses the phospholipase Cγ-protein kinase C (PLC-γ-PKC)-MAPK pathway, whereas M-CSFR/PDGFRs use the PI3 kinase-Ras-MAPK pathway for cell proliferation. In phylogenetic development, the VEGFR-like receptor in nonvertebrates appears to be the ancestor of the 7 Ig- and 5 Ig-RTK families because most nonvertebrates have only a single 7 Ig-RTK gene. In mammals, VEGFRs are deeply involved in pathological angiogenesis, including cancer and inflammation. Thus, an efficient inhibitor targeting VEGFRs could be useful in suppressing various diseases.
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283
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Ihnatko R, Edén U, Lagali N, Dellby A, Fagerholm P. Analysis of protein composition and protein expression in the tear fluid of patients with congenital aniridia. J Proteomics 2013; 94:78-88. [PMID: 24061003 DOI: 10.1016/j.jprot.2013.09.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 08/14/2013] [Accepted: 09/05/2013] [Indexed: 01/13/2023]
Abstract
UNLABELLED Aniridia is a rare congenital genetic disorder caused by haploinsuffiency of the PAX6 gene, the master gene for development of the eye. The expression of tear proteins in aniridia is unknown. To screen for proteins involved in the aniridia pathophysiology, the tear fluid of patients with diagnosed congenital aniridia was examined using two-dimensional electrophoresis (2-DE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Two-dimensional map of tear proteins in aniridia has been established and 7 proteins were differentially expressed with P<0.01 between aniridia patients and control subjects. Five of them were more abundant in healthy subjects, particularly α-enolase, peroxiredoxin 6, cystatin S, gelsolin, apolipoprotein A-1 and two other proteins, zinc-α2-glycoprotein and lactoferrin were more expressed in the tears of aniridia patients. Moreover, immunoblot analysis revealed elevated levels of vascular endothelial growth factor (VEGF) in aniridia tears which is in concordance with clinical finding of pathological blood and lymph vessels in the central and peripheral cornea of aniridia patients. The proteins with different expression in patients' tears may be new candidate molecules involved in the pathophysiology of aniridia and thus may be helpful for development of novel treatment strategies for the symptomatic therapy of this vision threatening condition. BIOLOGICAL SIGNIFICANCE This study is first to demonstrate protein composition and protein expression in aniridic tears and identifies proteins with different abundance in tear fluid from patients with congenital aniridia vs. healthy tears.
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Affiliation(s)
- Robert Ihnatko
- Integrative Regenerative Medicine Centre and Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, 581 85 Linköping, Sweden.
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284
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Abstract
In this issue of Blood, Singh et al establish the existence of a new soluble isoform of vascular endothelial growth factor receptor 3 (sVEGFR-3), which is synthesized and secreted by corneal epithelial cells; they show that sVEGFR-3 modulates lymphangiogenesis by impounding vascular endothelial growth factor (VEGF) C and rendering it unable to activate its cognate receptors, thereby maintaining the natural alymphatic disposition of the cornea.
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285
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TNFSF15 inhibits vasculogenesis by regulating relative levels of membrane-bound and soluble isoforms of VEGF receptor 1. Proc Natl Acad Sci U S A 2013; 110:13863-8. [PMID: 23918400 DOI: 10.1073/pnas.1304529110] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Mouse bone marrow-derived Lin(-)-Sca-1(+) endothelial progenitor cell (EPC) has pluripotent abilities such as supporting neovascularization. Vascular endothelial growth factor (VEGF) receptor 1 (VEGFR1) (Flt1) recognizes various VEGF isoforms and is critically implicated in a wide range of physiological and pathological settings, including vasculogenesis. Mouse EPC expresses two isoforms of VEGFR1: mFlt1, which transmits ligand-induced signals; and sFlt1, which acts as a negative regulator by sequestering ligands of VEGF receptors. How the relative levels of mFlt1 and sFlt1 are regulated is not yet clear. We report here that tumor necrosis factor superfamily 15 (TNFSF15) (also known as VEGI or TL1A), an endothelial cell-secreted cytokine, simultaneously promotes mFlt1 degradation and up-regulates sFlt1 expression in EPC, giving rise to disruption of VEGF- or PlGF-induced activation of eNOS and MAPK p38 and effective inhibition of VEGF-driven, EPC-supported vasculogenesis in a murine Matrigel implant model. TNFSF15 treatment of EPC cultures facilitates Akt deactivation-dependent, ubiquitin-assisted degradation of mFlt1 and stimulates sFlt1 expression by activating the PKC, Src, and Erk1/2 signaling pathway. Additionally, TNFSF15 promotes alternative splicing of the Flt1 gene in favor of sFlt1 production by down-regulating nuclear protein Jumonji domain-containing protein 6 (Jmjd6), thus alleviating Jmjd6-inhibited sFlt1 expression. These findings indicate that TNFSF15 is a key component of a molecular mechanism that negatively modulates EPC-supported vasculogenesis through regulation of the relative levels of mFlt1 and sFlt1 in EPC.
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286
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287
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Raikwar NS, Liu KZ, Thomas CP. Protein kinase C regulates FLT1 abundance and stimulates its cleavage in vascular endothelial cells with the release of a soluble PlGF/VEGF antagonist. Exp Cell Res 2013; 319:2578-87. [PMID: 23911939 DOI: 10.1016/j.yexcr.2013.07.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Revised: 06/25/2013] [Accepted: 07/09/2013] [Indexed: 01/18/2023]
Abstract
FLT1 and its soluble form (sFLT1) arise as alternate transcripts from the same gene and sFLT1 can antagonize the effect of vascular endothelial growth factor (VEGF) on its cognate receptors. We investigated the effect of VEGF and protein kinase C (PKC) activation on sFLT1 abundance. We demonstrated that VEGF stimulates sFLT1 and FLT1 mRNA and protein levels in vascular endothelial cells via VEGFR2 and PKC. Using an FLT1 expression vector with N and C-terminal epitope tags, we show that PKC activation increases the cleavage of FLT1 into an N-terminal extracellular fragment and a C-terminal intracellular fragment with the cleavage occurring adjacent to the transmembrane domain. The trafficking and glycosylation inhibitors brefeldin, monensin and tunicamycin substantially reduced cleavage and release of the N-terminal ectodomain of FLT1 and inhibited secretion of the isoforms of sFLT1. The shed FLT1 ectodomain can bind VEGF and PlGF and inhibit VEGF-induced vascular tube formation thus confirming that it is functionally equivalent to the alternately spliced and secreted sFLT1 isoforms.
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Affiliation(s)
- Nandita S Raikwar
- Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, IA, USA
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288
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Koch S, Claesson-Welsh L. Signal transduction by vascular endothelial growth factor receptors. Cold Spring Harb Perspect Med 2013; 2:a006502. [PMID: 22762016 DOI: 10.1101/cshperspect.a006502] [Citation(s) in RCA: 595] [Impact Index Per Article: 54.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Vascular endothelial growth factors (VEGFs) are master regulators of vascular development and of blood and lymphatic vessel function during health and disease in the adult. It is therefore important to understand the mechanism of action of this family of five mammalian ligands, which act through three receptor tyrosine kinases (RTKs). In addition, coreceptors like neuropilins (NRPs) and integrins associate with the ligand/receptor signaling complex and modulate the output. Therapeutics to block several of the VEGF signaling components have been developed with the aim to halt blood vessel formation, angiogenesis, in diseases that involve tissue growth and inflammation, such as cancer. In this review, we outline the current information on VEGF signal transduction in relation to blood and lymphatic vessel biology.
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Affiliation(s)
- Sina Koch
- Uppsala University, Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, 751 85 Uppsala, Sweden
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289
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[Corneal neovascularization: epidemiological, physiopathological, and clinical features]. J Fr Ophtalmol 2013; 36:627-39. [PMID: 23891320 DOI: 10.1016/j.jfo.2013.03.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Revised: 03/10/2013] [Accepted: 03/11/2013] [Indexed: 01/01/2023]
Abstract
Corneal neovascularization is defined as the presence of vessels within the normally avascular corneal stroma. This physiopathological process is the consequence of local hyper-expression of pro-angiogenic factors in response to tissue damage. These new vessels (neovessels), initially immature and poorly developed, predispose the cornea to lipid exudation, inflammation, and scarring. Additionally, the influx of vascular cells into the stroma induces a loss of the cornea's immune privilege, resulting in a higher rate of graft rejection. In this literature review, we touch on epidemiological, physiopathological, and clinical aspects of corneal neovascularization, as well as secondary complications.
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290
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Bryant-Hudson K, Conrady CD, Carr DJJ. Type I interferon and lymphangiogenesis in the HSV-1 infected cornea - are they beneficial to the host? Prog Retin Eye Res 2013; 36:281-91. [PMID: 23876483 DOI: 10.1016/j.preteyeres.2013.06.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 06/19/2013] [Accepted: 06/25/2013] [Indexed: 02/06/2023]
Abstract
Herpes simplex virus type 1 (HSV-1) is a highly successful pathogen that can result in significant human morbidity. Within the cornea, it was thought the initial recognition of the pathogen was through Toll-like receptors expressed on/in resident cells that then elicit pro-inflammatory cytokine production, activation of anti-viral pathways, and recruitment of leukocytes. However, our lab has uncovered a novel, TLR-independent innate sensor that supersedes TLR induction of anti-viral pathways following HSV-1 infection. In addition, we have also found HSV-1 induces the genesis of lymphatic vessels into the cornea proper by a mechanism independent of TLRs and unique in the field of neovascularization. This review will focus on these two innate immune events during acute HSV-1 infection of the cornea.
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Affiliation(s)
- Katie Bryant-Hudson
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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291
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Abstract
Dry eye is a common ocular surface inflammatory disease that significantly affects quality of life. Dysfunction of the lacrimal function unit (LFU) alters tear composition and breaks ocular surface homeostasis, facilitating chronic inflammation and tissue damage. Accordingly, the most effective treatments to date are geared towards reducing inflammation and restoring normal tear film. The pathogenic role of CD4+ T cells is well known, and the field is rapidly realizing the complexity of other innate and adaptive immune factors involved in the development and progression of disease. The data support the hypothesis that dry eye is a localized autoimmune disease originating from an imbalance in the protective immunoregulatory and proinflammatory pathways of the ocular surface.
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Affiliation(s)
- Michael E Stern
- Biological Sciences, Inflammation Research Program, Allergan Inc., Irvine, CA 92612, USA. stern
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292
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Luo L, Uehara H, Zhang X, Das SK, Olsen T, Holt D, Simonis JM, Jackman K, Singh N, Miya TR, Huang W, Ahmed F, Bastos-Carvalho A, Le YZ, Mamalis C, Chiodo VA, Hauswirth WW, Baffi J, Lacal PM, Orecchia A, Ferrara N, Gao G, Young-Hee K, Fu Y, Owen L, Albuquerque R, Baehr W, Thomas K, Li DY, Chalam KV, Shibuya M, Grisanti S, Wilson DJ, Ambati J, Ambati BK. Photoreceptor avascular privilege is shielded by soluble VEGF receptor-1. eLife 2013; 2:e00324. [PMID: 23795287 PMCID: PMC3687373 DOI: 10.7554/elife.00324] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 05/08/2013] [Indexed: 12/30/2022] Open
Abstract
Optimal phototransduction requires separation of the avascular photoreceptor layer from the adjacent vascularized inner retina and choroid. Breakdown of peri-photoreceptor vascular demarcation leads to retinal angiomatous proliferation or choroidal neovascularization, two variants of vascular invasion of the photoreceptor layer in age-related macular degeneration (AMD), the leading cause of irreversible blindness in industrialized nations. Here we show that sFLT-1, an endogenous inhibitor of vascular endothelial growth factor A (VEGF-A), is synthesized by photoreceptors and retinal pigment epithelium (RPE), and is decreased in human AMD. Suppression of sFLT-1 by antibodies, adeno-associated virus-mediated RNA interference, or Cre/lox-mediated gene ablation either in the photoreceptor layer or RPE frees VEGF-A and abolishes photoreceptor avascularity. These findings help explain the vascular zoning of the retina, which is critical for vision, and advance two transgenic murine models of AMD with spontaneous vascular invasion early in life. DOI:http://dx.doi.org/10.7554/eLife.00324.001.
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Affiliation(s)
- Ling Luo
- Moran Eye Center , University of Utah , Salt Lake City , United States ; Department of Ophthalmology , The 306th Hospital of PLA , Beijing , China
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293
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Abstract
Researchers have identified a soluble receptor that prevents blood vessels forming in the outer retina-a process that can lead to blindness-by sequestering vascular endothelial growth factor.
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Affiliation(s)
- Dawn Sim
- is at the UCL Institute of Ophthalmology , London , United Kingdom
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294
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Lacritin and the tear proteome as natural replacement therapy for dry eye. Exp Eye Res 2013; 117:39-52. [PMID: 23769845 DOI: 10.1016/j.exer.2013.05.020] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 05/23/2013] [Accepted: 05/31/2013] [Indexed: 12/21/2022]
Abstract
Tear proteins are potential biomarkers, drug targets, and even biotherapeutics. As a biotherapeutic, a recombinant tear protein might physiologically rescue the ocular surface when a deficiency is detected. Such a strategy pays more attention to the natural prosecretory and protective properties of the tear film and seeks to alleviate symptoms by addressing cause, rather than the current palliative, non-specific and temporary approaches. Only a handful of tear proteins appear to be selectively downregulated in dry eye, the most common eye disease. Lacritin and lipocalin-1 are two tear proteins selectively deficient in dry eye. Both proteins influence ocular surface health. Lacritin is a prosecretory mitogen that promotes basal tearing when applied topically. Levels of active monomeric lacritin are negatively regulated by tear tissue transglutaminase, whose expression is elevated in dry eye with ocular surface inflammation. Lipocalin-1 is the master lipid sponge of the ocular surface, without which residual lipids could interfere with epithelial wetting. It also is a carrier for vitamins and steroid hormones, and is a key endonuclease. Accumulation of DNA in tears is thought to be proinflammatory. Functions of these and other tear proteins may be influenced by protein-protein interactions. Here we discuss new advances in lacritin biology and provide an overview on lipocalin-1, and newly identified members of the tear proteome.
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295
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Affiliation(s)
- Caroline J. Zeiss
- Section of Comparative Medicine; Yale University School of Medicine; 375 Congress Ave New Haven CT 06520 USA
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296
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Bath C. Human corneal epithelial subpopulations: oxygen dependent ex vivo expansion and transcriptional profiling. Acta Ophthalmol 2013; 91 Thesis 4:1-34. [PMID: 23732018 DOI: 10.1111/aos.12157] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Corneal epithelium is being regenerated throughout life by limbal epithelial stem cells (LESCs) believed to be located in histologically defined stem cell niches in corneal limbus. Defective or dysfunctional LESCs result in limbal stem cell deficiency (LSCD) causing pain and decreased visual acuity. Since the first successful treatment of LSCD by transplantation of ex vivo expanded LESCs in 1997, many attempts have been carried out to optimize culture conditions to improve the outcome of surgery. To date, progress in this field of bioengineering is substantially hindered by both the lack of specific biomarkers of LESCs and the lack of a precise molecular characterization of in situ epithelial subpopulations. The aim of this dissertation was to optimize culture systems with regard to the environmental oxygen concentration for selective ex vivo expansion of LESCs and to analyse in situ subpopulations in human corneal epithelium using a combination of laser capture microdissection and RNA sequencing for global transcriptomic profiling. We compared dissociation cultures, using either expansion on γ-irradiated NIH/3T3 feeder cells in serum-rich medium or expansion directly on plastic in serum-free EpiLife medium, using a range of physiologically relevant oxygen concentrations (2%, 5%, 10%, 15% and 20%). Using immunocytochemistry and advanced fluorescence microscopy, cells were characterized regarding growth, cell cycle distribution, colony-forming efficiency (CFE), phenotypes and cytomorphometry. Limbal epithelial cells expanded in 2% O2 exhibited slow growth, low fraction of cells in S/G2 , high CFE, high expression of stem cell markers ABCG2 and p63α, and low fraction of differentiation marker CK3 resembling a LESC phenotype. The effect of hypoxia to maintain LESCs in culture was not dependent on the system used for propagation (Bath et al. 2013a). Laser capture microdissection was used to isolate cellular subpopulations in situ from the spatially defined differentiation pathway in human corneal epithelium according to an optimized protocol for maintenance of expression profiles. Isolated total RNA from basal limbal crypts (BLCs), superficial limbal crypts (SLCs), paracentral/central cornea and limbal stroma was amplified and converted to fragmented cDNA libraries for use in deep paired-end next-generation sequencing. Global transcriptional profiling was carried out using bioinformatics. The location of primitive cells in BLCs, migratory and activated cells in SLCs and differentiated cells in paracentral/central cornea was evident from mapping of significantly upregulated genes in each compartment to the gene ontology (GO). Interestingly, many GO terms in BLCs were also involved in neurogenic processes, whereas many GO terms in SLCs were related to vasculature. Mapping upregulated genes in BLCs to pathway annotations in Kyoto Encyclopedia of Genes and Genomes described many active pathways as signalling and cancer-associated pathways. We supply extensive information on possible novel biomarkers, reveal insight into both active pathways and novel regulators of LESCs such as Lrig1 and SOX9 and provide an immense amount of data for future exploration (Bath et al. 2013b). Selective ex vivo expansion of LESCs in hypoxia and the comprehensive molecular characterization of corneal epithelial subpopulations in situ are expected to be beneficial for the future treatment of LSCD by cultured limbal epithelial transplantation.
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Affiliation(s)
- Chris Bath
- Department of Ophthalmology, Aalborg University Hospital, Aalborg, Denmark
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297
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Corneal endothelial safety following subconjunctival and intrastromal injection of bevacizumab for corneal neovascularization. Int Ophthalmol 2013; 34:597-601. [DOI: 10.1007/s10792-013-9807-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 05/21/2013] [Indexed: 10/26/2022]
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298
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Bath C, Muttuvelu D, Emmersen J, Vorum H, Hjortdal J, Zachar V. Transcriptional dissection of human limbal niche compartments by massive parallel sequencing. PLoS One 2013; 8:e64244. [PMID: 23717577 PMCID: PMC3661480 DOI: 10.1371/journal.pone.0064244] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Accepted: 04/10/2013] [Indexed: 12/13/2022] Open
Abstract
Corneal epithelium is maintained throughout life by well-orchestrated proliferation of limbal epithelial stem cells (LESCs), followed by migration and maturation centripetally towards the ocular surface. Disturbance of LESCs can potentially lead to a blinding condition, which can be reversed by reconstitution of a functional LESC pool. The current clinical procedures are effective to some degree, however, deeper knowledge of the molecular interplay within the limbal niche is necessary to achieve a fully satisfactory patient outcome. The present study was thus undertaken to carry out a comprehensive transcriptome analysis of four distinct human limbal compartments, including basal limbal crypts (BLCs), superficial limbal crypts (SLCs), cornea, and the supporting stroma, with the aid of laser capture microdissection and deep RNA sequencing. The tissue harvest pipeline was rigorously optimized so that the exposure to cold ischemia would be less than five minutes. The global gene ontology analysis confirmed existence of primitive cells in BLCs, migratory and activated cells in SLCs, and differentiated cells in cornea. Interestingly, many significantly upregulated genes in SLCs mapped to processes involved in regulation of vasculature, such as sFLT1. In contrast, BLCs exhibited many genes mapping to neurogenic processes and processes related to cell development. The primitive nature of BLCs was, furthermore, confirmed by the KEGG pathway analysis, and some potential regulators of LESCs were revealed, such as Lrig1 and SOX9. The analysis also yielded comprehensive lists of uniquely expressed genes in both BLCs and cornea, which may be useful to identify possible biomarkers. In conclusion, the current investigation provides new insight into the relationship between distinct cell populations within the limbal niche, identifies candidates to be verified for novel biological functions, and yields a wealth of information for prospective data mining.
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Affiliation(s)
- Chris Bath
- Department of Ophthalmology, Aalborg University Hospital, Aalborg, Denmark
- Laboratory for Stem Cell Research, Aalborg University, Aalborg, Denmark
| | - Danson Muttuvelu
- Department of Ophthalmology, Aalborg University Hospital, Aalborg, Denmark
| | - Jeppe Emmersen
- Laboratory for Stem Cell Research, Aalborg University, Aalborg, Denmark
| | - Henrik Vorum
- Department of Ophthalmology, Aalborg University Hospital, Aalborg, Denmark
| | - Jesper Hjortdal
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark
| | - Vladimir Zachar
- Laboratory for Stem Cell Research, Aalborg University, Aalborg, Denmark
- * E-mail:
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299
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Chatterjee S, Wang Y, Duncan MK, Naik UP. Junctional adhesion molecule-A regulates vascular endothelial growth factor receptor-2 signaling-dependent mouse corneal wound healing. PLoS One 2013; 8:e63674. [PMID: 23667656 PMCID: PMC3648504 DOI: 10.1371/journal.pone.0063674] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 04/07/2013] [Indexed: 12/04/2022] Open
Abstract
Inflammation and angiogenesis are integral parts of wound healing. However, excessive and persistent wound-induced inflammation and angiogenesis in an avascular tissue such as the cornea may be associated with scarring and visual impairment. Junctional adhesion molecule A (Jam-A) is a tight junction protein that regulates leukocyte transmigration as well as fibroblast growth factor-2 (FGF-2)-induced angiogenesis. However its function in wound-induced inflammation and angiogenesis is still unknown. In this study, we report spontaneous corneal opacity in Jam-A deficient mice associated with inflammation, angiogenesis and the presence of myofibroblasts. Since wounds and/or corneal infections cause corneal opacities, we tested the role of Jam-A in wound-induced inflammation, angiogenesis and scarring by subjecting Jam-A deficient mice to full thickness corneal wounding. Analysis of these wounds demonstrated increased inflammation, angiogenesis, and increased number of myofibroblasts thereby indicating that Jam-A regulates the wound-healing response by controlling wound-induced inflammation, angiogenesis and scarring in the cornea. These effects were not due to inflammation alone since the inflammation-induced wound-healing response in Jam-A deficient mice was similar to wild type mice. In order to determine the molecular mechanism associated with the observed aberrant corneal wound healing in Jam-A deficient mice, we assessed the expression of the components of vascular endothelial growth factor A (VEGF-A)/vascular endothelial growth factor receptor- 2(VEGFR-2) signaling pathway. Interestingly, we observed increased levels of VEGF-A mRNA in Jam-A deficient eyes. We also observed nuclear localization of phosphorylated SMAD3 (pSMAD3) indicative of TGFβ pathway activation in the Jam-A deficient eyes. Furthermore the increased wound-induced corneal inflammation, angiogenesis, and scarring in Jam-A deficient mice was attenuated by treatment with DC101, an anti-vascular endothelial growth factor receptor-2 (VEGFR-2) antibody. Our results suggest that in the absence of Jam-A, the VEGF-A/VEGFR-2 pathway is upregulated, thereby augmenting wound induced corneal inflammation, angiogenesis, and myofibroblast accumulation leading to scarring.
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Affiliation(s)
- Sharmila Chatterjee
- Department of Biological Sciences, University of Delaware, Newark, Delaware, United States of America
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300
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Short- and long-term corneal vascular effects of tafluprost eye drops. Graefes Arch Clin Exp Ophthalmol 2013; 251:1919-27. [PMID: 23624591 DOI: 10.1007/s00417-013-2345-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 03/14/2013] [Accepted: 04/02/2013] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Prostaglandin analogs are first line therapy in the treatment of glaucoma, but also display side effects during ocular inflammation. In this context, the potential side effects of prostaglandin analogs on the normally avascular cornea, the main application route for eye drops, are so far not fully defined. Therefore, the aim of this study was to evaluate the vascular effects of the prostaglandin analog tafluprost on the healthy and inflamed cornea. METHODS For in vitro studies, blood and lymphatic endothelial cells were treated with tafluprost; cell proliferation was assessed after 48 h. For long-term in vivo studies under healthy conditions, naïve corneas of BALB/c mice were treated with tafluprost eye drops for 4 weeks. For short-term in vivo studies under inflammatory conditions, corneal inflammation was induced by suture placement; mice then received tafluprost eye drops for 1 week. Afterwards, corneas were stained with CD31 as panendothelial and LYVE-1 as lymphendothelial (and macrophage) marker. RESULTS In vitro, tafluprost did not alter blood or lymphatic endothelial cell proliferation. In vivo, there was no change in limbal blood or lymphatic vessel anatomy after long-term treatment with tafluprost. Short-term treatment with tafluprost under inflammatory conditions did not influence the recruitment of LYVE-1 positive macrophages into the cornea. Moreover, treatment of inflamed corneas with tafluprost did not significantly influence corneal hem- and lymphangiogenesis. CONCLUSIONS Tafluprost does not affect blood and lymphatic vessel growth, neither under resting nor under inflammatory conditions. These findings suggest a safe vascular profile of tafluprost eye drops at the inflammatory neovascularized cornea.
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