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Ocular delivery of sunitinib-loaded nanoparticles doped in tragacanthic acid hydrogel in treatment of diabetic retinopathy in rats. Drug Dev Ind Pharm 2022; 48:29-39. [PMID: 35723593 DOI: 10.1080/03639045.2022.2092745] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus. This study aimed to compare the effect of sunitinib-loaded poly (glycerol sebacate) (PGS)/gelatin nanoparticles doped in an injectable hydrogel with bevacizumab as a standard treatment of DR. METHODS The shear-sensitive hydrogel was prepared based on tragacanthic acid (TA) cross-linked with sodium acetate. DR was induced in rats by streptozotocin (STZ), and the animals were injected intravitreally a single dose of 20 µL sunitinib solution in three different concentrations (12.5, 25, and 50 µg/mL), sunitinib-loaded nanoparticles in hydrogel (413 μg/mL) and bevacizumab solution (6.25 mg/mL). The efficacy of the treatments was studied by histological and immunohisitological tests, angiogenesis, and optical coherence tomography (OCT). Vascular endothelial growth factor (VEGF) concentration was measured in the retina. RESULTS The results revealed that 20 µL of sunitinib with the concentration of 25 µg/mL was effective in DR without any disruption in the retina or any other side effects. This dose was considered the therapeutic dose for nanoparticles. Sunitinib loaded PGS/gelatine nanoparticles that were incorporated in the injectable hydrogel were as effective as bevacizumab in controlling DR. Although sunitinib solution reduced VEGF production and neovascularization in the retina compared to the negative control group, it was not as suitable as the nanoparticles. TA-based hydrogel showed no toxicity on the normal retina, and the angiography and histologic studies confirmed the VEGF results. Conclusions: Sunitinib nanoparticles doped in TA hydrogel may be an appropriate substitution of bevacizumab in the treatment of DR.
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Multimodal imaging of a vascularized idiopathic epiretinal membrane. Eur J Ophthalmol 2020; 32:1120672120982523. [PMID: 33325264 DOI: 10.1177/1120672120982523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE To report a case of vascularized idiopathic epiretinal membrane including the multimodal imaging. METHODS Findings on clinical examination, color fundus photography, spectral-domain optical coherence tomography, optical coherence tomography angiography, and fluorescein angiography. RESULTS Sixty-three-year-old woman with a previous rhegmatogenous retinal detachment (RRD) who presented with an asymptomatic idiopathic neovascular complex below an epiretinal membrane. It was assessed with fluorescein angiography, OCT and OCT-A. The vascularized ERM was already present previously to the retinal detachment. CONCLUSION Our case report describes an example of idiopathic epiretinal membrane complicated by neovascularization; we hypothesized hypertension could be one of the factors in this case, as it may lead to decreased retinal perfusion and upregulation in vascular endothelial growth factor (VEGF). Multimodal imaging can help in detecting neovascularized ERM.
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Inhibition of miR-21-5p suppresses high glucose-induced proliferation and angiogenesis of human retinal microvascular endothelial cells by the regulation of AKT and ERK pathways via maspin. Biosci Biotechnol Biochem 2018; 82:1366-1376. [PMID: 29658404 DOI: 10.1080/09168451.2018.1459179] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The aim of the present study is to investigate the role of miR-21-5p in angiogenesis of human retinal microvascular endothelial cells (HRMECs). HRMECs were incubated with 5 mM glucose, 30 mM glucose or 30 mM mannitol for 24 h, 48 h or 72 h. Then, HRMECs exposed to 30 mM glucose were transfected with miR-21-5p inhibitor. We found that high glucose increased the expression of miR-21-5p, VEGF, VEGFR2 and cell proliferation activity. Inhibition of miR-21-5p reduced high glucose-induced proliferation, migration, tube formation of HRMECs, and reversed the decreased expression of maspin as well as the abnormal activation of PI3K/AKT and ERK pathways. Down-regulation of maspin by siRNA significantly increased the activities of PI3K/AKT and ERK pathways. In conclusion, inhibition of miR-21-5p could suppress high glucose-induced proliferation and angiogenesis of HRMECs, and these effects may partly dependent on the regulation of PI3K/AKT and ERK pathways via its target protein maspin.
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DNA Methylomes Reveal Biological Networks Involved in Human Eye Development, Functions and Associated Disorders. Sci Rep 2017; 7:11762. [PMID: 28924151 PMCID: PMC5603607 DOI: 10.1038/s41598-017-12084-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 09/04/2017] [Indexed: 01/07/2023] Open
Abstract
This work provides a comprehensive CpG methylation landscape of the different layers of the human eye that unveils the gene networks associated with their biological functions and how these are disrupted in common visual disorders. Herein, we firstly determined the role of CpG methylation in the regulation of ocular tissue-specification and described hypermethylation of retinal transcription factors (i.e., PAX6, RAX, SIX6) in a tissue-dependent manner. Second, we have characterized the DNA methylome of visual disorders linked to internal and external environmental factors. Main conclusions allow certifying that crucial pathways related to Wnt-MAPK signaling pathways or neuroinflammation are epigenetically controlled in the fibrotic disorders involved in retinal detachment, but results also reinforced the contribution of neurovascularization (ETS1, HES5, PRDM16) in diabetic retinopathy. Finally, we had studied the methylome in the most frequent intraocular tumors in adults and children (uveal melanoma and retinoblastoma, respectively). We observed that hypermethylation of tumor suppressor genes is a frequent event in ocular tumors, but also unmethylation is associated with tumorogenesis. Interestingly, unmethylation of the proto-oncogen RAB31 was a predictor of metastasis risk in uveal melanoma. Loss of methylation of the oncogenic mir-17-92 cluster was detected in primary tissues but also in blood from patients.
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Preoperative subconjunctival combined injection of bevacizumab and mitomycin C before the surgical excision of primary pterygium: clinical and histological results. Clin Ophthalmol 2017; 11:493-501. [PMID: 28331283 PMCID: PMC5354544 DOI: 10.2147/opth.s127700] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Purpose The aim of this study was to detect the clinical and histological effects of preoperative subconjunctival injection of both bevacizumab and mitomycin C (MMC) 1 month before the surgical excision of primary pterygium using a bare sclera technique. Patients and methods A total of 20 patients with primary pterygium underwent subconjunctival combined injection of 0.1 mL of MMC (0.1 mg/mL) and 0.1 mL of bevacizumab (1.25 mg/0.1 mL) 1 month before bare sclera excision of the pterygium. The excised pterygium tissues were examined histologically and immunohistologically by CD31 staining, and the patients were followed up clinically for at least 2 years. The excised pterygia of two patients without preoperative injection were used for histological comparison. Results Clinically, there were no intraoperative or postoperative complications. No recurrence was noted during the follow-up period. Histologically, the previously injected pterygia showed a decreased number of epithelial cells and stromal fibroblasts. The latter were rounded or oval and swollen rather than spindle shaped, and some were degenerating or apoptotic. Collagen and elastic fibers were degenerated, distorted, and decreased in density, while blood capillaries were obliterated. There was a significant decrease in CD31-positive cells in previously injected pterygia. Conclusion Preoperative subpterygium combined injection of bevacizumab and MMC is safe and effective in reducing the postoperative recurrence of primary pterygium. Histological and immunohistological changes in the form of decreased fibrovascular activity and degeneration of the extracellular matrix and nerve axons were noted.
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ABNORMAL VASCULAR COMPLEX WITHIN AN IDIOPATHIC EPIRETINAL MEMBRANE IMAGED BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY. Retin Cases Brief Rep 2017; 13:127-129. [PMID: 28277440 DOI: 10.1097/icb.0000000000000569] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To report the case 70-year-old patient presenting with preretinal, abnormal vascularization accompanying an idiopathic epiretinal membrane (ERM), identified by optical coherence tomography angiography. METHODS Observational case report of one patient. RESULTS The authors describe the case of a patient presenting with an ERM on the right eye since March 2011, diagnosed by fundus biomicroscopy and spectral domain optical coherence tomography (Spectralis; Heidelberg Engineering, Heidelberg, Germany). At the last follow-up visit, the patient had a Snellen best-corrected visual acuity of 20/32 in her right eye and 20/20 in her left eye. Although on spectral domain optical coherence tomography the aspect on the right eye was unchanged since prior examination, optical coherence tomography angiography (Angiovue; Optovue, Fremont, CA) was able to reveal a high-flow, abnormal vascular network in the preretinal manual segmentation corresponding to the ERM. CONCLUSION Spectral domain optical coherence tomography, routinely performed in these patients, may underestimate the presence of abnormal vascularization, as both preretinal neovascular complexes and thick ERMs appear as hyperreflective structures. Optical coherence tomography angiography allows a fast and depth-resolved visualization of these abnormal vascular complexes inside idiopathic ERMs. Diagnosis of a vascularized epiretinal structure could be noteworthy before decision of retinal surgery.
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Statin medication in patients with epiretinal membrane is associated with low intravitreal EPO, TGF-beta-1, and VEGF levels. Clin Ophthalmol 2016; 10:921-8. [PMID: 27284236 PMCID: PMC4883812 DOI: 10.2147/opth.s105686] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Background In eyes with idiopathic epiretinal membrane (iERM), the intravitreal growth factor and cytokine levels may associate with postvitrectomy outcomes. Here, we have analyzed the perioperative intravitreal protein levels of potent vasoactive, proinflammatory, and extracellular matrix-remodeling factors in iERM eyes and evaluated the postvitrectomy outcomes. Methods This was an institutional, observational study. Eyes operated on for iERM (n=26) were analyzed according to the use of statin medication. Vitreous samples were subjected to protein measurements of angiopoietin-1 and -2, erythropoietin, transforming growth factor-β1, and vascular endothelial growth factor by enzyme-linked immunosorbent assay, and of matrix metalloproteinase-2 and -9 by gelatin zymography. One-month visual outcomes and 1-year revitrectomy rates were recorded. Results In iERM eyes of patients taking statins, intravitreal levels of erythropoietin (mean ± standard deviation, 10.8±4.9 vs 82.9±119.5 mIU/mg, P=0.003), transforming growth factor-β1 (2.3±4.7 vs 15.8±16.3 pg/mg, P=0.035), and vascular endothelial growth factor (5.5±9.9 vs 236.6±491.6 pg/mg, P=0.006) were lower than in nonstatin-treated patients. At 1-month, visual gain did not significantly differ between iERM eyes of patients with statins and those without (improvement 0.27±0.20 vs 0.16±0.38 logarithm of the minimum angle of resolution units, P=0.118). Conclusion Systemic statin therapy might have a favorable effect on intravitreal factors involved in vascular permeability, inflammation, and fibroproliferation in aging human iERM eyes.
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Ceramide production mediates cinobufotalin-induced growth inhibition and apoptosis in cultured hepatocellular carcinoma cells. Tumour Biol 2015; 36:5763-71. [PMID: 25724183 DOI: 10.1007/s13277-015-3245-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 02/10/2015] [Indexed: 12/21/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is a highly aggressive and lethal neoplasm with poor prognosis. The aim of this study is to investigate the anticancer activity of cinobufotalin, a bufadienolide isolated from toad venom, in cultured HCC cells, and to study the underlying mechanisms. We found that cinobufotalin (at nmol/L) significantly inhibited HCC cell growth and survival while inducing considerable cell apoptosis. Further, cinobufotalin inhibited sphingosine kinase 1 (SphK1) activity and induced pro-apoptotic ceramide production. Ceramide synthase-1 small hairpin RNA (shRNA)-depletion inhibited cinobufotalin-induced ceramide production and HCC cell apoptosis. On the other hand, the glucosylceramide synthase (GCS) inhibitor 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) facilitated cinobufotalin-induced ceramide production and cell apoptosis. SphK1 inhibitor II (SKI-II), similar to cinobufotalin, increased cellular ceramide level and promoted HCC cell apoptosis. Finally, we observed that cinobufotalin inactivated Akt-S6K1 signaling in HepG2 cells, which was again inhibited by ceramide synthase-1 shRNA-depletion. In conclusion, the results of this study suggest that cinobufotalin induces growth inhibition and apoptosis in cultured HCC cells through ceramide production. Cinobufotalin may be investigated as a novel anti-HCC agent.
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Statins in rhegmatogenous retinal detachment are associated with low intravitreal angiopoietin-2, VEGF and MMP-2 levels, and improved visual acuity gain in vitrectomized patients. Graefes Arch Clin Exp Ophthalmol 2014; 253:1685-93. [PMID: 25432094 DOI: 10.1007/s00417-014-2873-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 10/22/2014] [Accepted: 11/19/2014] [Indexed: 01/08/2023] Open
Abstract
PURPOSE In rhegmatogenous retinal detachment (RRD), intravitreal growth factors and cytokines may compromise post-vitrectomy outcomes. Here, we analysed perioperative intravitreal protein levels of potent vasoactive, pro-inflammatory, and extracellular matrix-remodelling factors in RRD eyes of patients treated with statins and evaluated post-vitrectomy outcome in the same study eyes. METHODS Institutional, retrospective, observational study of 14 patients operated on for RRD while on statins compared to patients without statin medication (n = 82). Vitreous samples were subjected to protein measurements of angiopoietin (ANGPT)-1 and -2, transforming growth factor-β1, and vascular endothelial growth factor (VEGF) by ELISA, and of matrix metalloproteinase (MMP)-2 and -9 by gelatin zymography. A 1-month best-corrected visual acuity (BCVA) gain was modelled by Student's T-test and multivariate linear regression with concomitant perioperative medication. Cumulative 12-month revitrectomy frequency was modelled by Kaplan-Meier log-rank test. RESULTS Intravitreal levels of ANGPT-2 (49.2 ± 33.1 vs. 112.8 ± 134.1 pg/ml, mean ± SD, p < 0.001), VEGF (2.3 ± 2.4 vs. 17.7 ± 57.8 pg/ml, p = 0.021), and MMP-2 (1107.1 ± 884.6 vs 1976.4 ± 970.1 AU/ml, p = 0.005) in RRD eyes of patients treated with statins were lower than in non-statin-treated controls. Patients on statins had better 1-month BCVA improvement than did those not on statins (p = 0.022), with no difference in 1-year re-vitrectomy rates. CONCLUSIONS Intravitreal levels of ANGPT-2, VEGF, factors involved in vascular permeability and inflammation, and activity of MMP-2, the factor connected with breakdown of basement membrane and fibroproliferation, were lower in RRD eyes of patients with statin treatment. At 1-month, postoperative BCVA gain was improved in statin-treated RRD eyes, suggesting that statin administration may be effective in preventing inflammation-related PVR formation.
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Ranibizumab for idiopathic epiretinal membranes: A retrospective case series. Saudi J Ophthalmol 2013; 27:79-82. [PMID: 24227966 DOI: 10.1016/j.sjopt.2013.01.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 10/28/2012] [Accepted: 01/01/2013] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To study the effect of intravitreal ranibizumab on idiopathic epiretinal membranes (ERMs). METHODS A retrospective cohort study on a consecutive series of ranibizumab intravitreal injections for epiretinal membranes was performed. Four cases were identified by reviewing a claims database linked to electronic medical records. All patients received a total of three 0.05 mg/0.05 ml ranibizumab intravitreal injections at a monthly interval. The primary outcome measure was the final best-corrected visual acuity (BCVA) at the end of the injection series, and the final central macular thickness (CMT). RESULTS All four patients completed 3 months follow-up after the last ranibizumab injection. The mean baseline CMT was 509 microns (SD = 111). A trend was noticed for reduction in CMT (Δ = 41 microns) P = 0.08. Three patients improved by one line in their BCVA. The remaining patient maintained the same BCVA. No complications were noted. CONCLUSION In this study, intravitreal injection of ranibizumab marginally reduced retinal thickness in four patients with minimal improvement in visual acuity. No safety concerns were noticed. Further basic science and clinical studies may be warranted to assess the role of vascular endothelial growth factor and the effect of ranibizumab on idiopathic epiretinal membranes.
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Increased intravitreal angiopoietin-2 levels associated with rhegmatogenous retinal detachment. Graefes Arch Clin Exp Ophthalmol 2013; 252:881-8. [PMID: 24218041 DOI: 10.1007/s00417-013-2508-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 08/08/2013] [Accepted: 10/21/2013] [Indexed: 12/26/2022] Open
Abstract
PURPOSE To explore factors related to pathogenesis of rhegmatogenous retinal detachment (RRD) and development of proliferative vitreoretinopathy (PVR), vitreous levels of angiopoietin-1 and -2 (Ang-1 and -2), previously undefined in RRD, transforming growth factor-(TGF) β1, vascular endothelial growth factor (VEGF), erythropoietin (EPO) and proteolytic mediators of extracellular matrix remodelling (MMP-2 and -9) were compared in eyes with RRD and eyes with idiopathic macular hole or pucker. METHODS Vitreous samples were collected from 117 eyes with RRD (study group) and 40 eyes with macular hole or pucker (control group). Growth factors were measured by ELISA and matrix metalloproteinases (MMPs) by gelatin zymography. RESULTS The mean vitreous concentrations of Ang-2, MMP-2, and MMP-9 were higher (all p < 0.01), whereas concentration of VEGF was lower (p = 0.01) in eyes with RRD relative to controls. Logistic regression analysis identified Ang-2 concentration as a novel marker of RRD (p = 0.0001, OR 48.7). Ang-1, EPO, and total TGF-β1 levels were not significantly different between the groups. However, TGF-β1 and MMP-2 were increased in eyes with total RRD compared to those with local RRD (p ≤ 0.05). In eyes with PVR, no differences were observed in any studied marker as compared with non-PVR eyes. CONCLUSIONS Current results reveal Ang-2 as a key factor upregulated in RRD. It may co-operate with fibrosis-associated factors and contribute to vascular complications such as breakdown of blood-eye barrier and PVR development.
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Immunohistochemical Profile and VEGF, TGF-β and PGE2 in Human Pterygium and Normal Conjunctiva: Experimental Study and Review of the Literature. Int J Immunopathol Pharmacol 2012; 25:607-15. [PMID: 23058011 DOI: 10.1177/039463201202500307] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Human pterygium is made up of chronic proliferative fibro-vascular tissue growing on the ocular surface. This disease exhibits both degenerative and hyperplastic properties. Some fibroangiogenic factors have recently been shown to play a potential role in fibrovascular diseases via the angiogenesis process. The aim of this study is to evaluate VEGF, TGF-β and PGE2 expression in the epithelial, endothelial and stromal cells of human pterygium and normal conjunctiva in order to determine whether these factors participate in the development of pterygium. Ten specimens from patients with pterygium and two normal conjunctivas (cadavers) were analyzed by immunohistochemistry using specific antibodies against these growth factors. The technique used was ABC/HRP (Avidin complexed with biotinylated peroxidase). Immunoreactivity of VEGF was significantly increased in the epithelium, vascular endothelium and stromal cells in primary pterygium as compared with normal conjunctiva. A moderate expression of TGF-β in the pterygium was observed in the epithelial and stromal layers. On the contrary, immunolabeling of this growth factor in the human normal conjunctiva was weak. PGE2 was strongly expressed in the epithelium of patients with pterygium, as in control conjunctival tissues, and the immunolabeling was moderate in the stroma from the same patients. Our results suggest that these growth factors may contribute to the progression of primary pterygium by increasing angiogenesis, thus leading to the formation of new blood vessels from the pre-existing vasculature. We conclude that VEGF, TGF-β and PGE2 may be potential therapeutic targets in the treatment of this disease although proof of this evidence requires further studies.
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ANTIANGIOGENIC ISOFORMS OF VASCULAR ENDOTHELIAL GROWTH FACTOR PREDOMINATE IN SUBRETINAL FLUID OF PATIENTS WITH RHEGMATOGENOUS RETINAL DETACHMENT AND PROLIFERATIVE VITREORETINOPATHY. Retina 2012; 32:54-9. [DOI: 10.1097/iae.0b013e31821800b9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Regulation of cell-mediated collagen gel contraction in human retinal pigment epithelium cells by vascular endothelial growth factor compared with transforming growth factor-β2. Clin Exp Ophthalmol 2011; 40:e76-86. [PMID: 21668782 DOI: 10.1111/j.1442-9071.2011.02618.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND To explore the potential role of vascular endothelial growth factor compared with transforming growth factor-β2 in the regulation of human retinal pigment epithelium cell-mediated collagen gel contraction. METHODS The retinal pigment epithelium cell mediated type I collagen gel contraction assay was performed to evaluate and compare the effect of vascular endothelial growth factor and transforming growth factor-β2. The number of viable retinal pigment epithelium cells in the gel and the expression of α-smooth muscle actin were analysed. RESULTS Both vascular endothelial growth factor and transforming growth factor-β2 caused a time dependent gel contraction, associated with over expression of α-smooth muscle actin in retinal pigment epithelium cells undergoing a fibroblast like transformation. The decrease in volume of the collagen gel and increase in α-smooth muscle actin expression were more significant in the transforming growth factor-β2-treated group than in vascular endothelial growth factor-treated group beginning at day 2, and the growth of retinal pigment epithelium cells was significantly more inhibited in the transforming growth factor-β2-treated group compared with the vascular endothelial growth factor-treated group after day 1 (P < 0.05). Transforming growth factor-β2 stimulation increased both vascular endothelial growth factor mRNA expression and secretion. The α-smooth muscle actin expression and the change in volume of collagen gel were significantly positively correlated in both experimental groups. CONCLUSIONS Both vascular endothelial growth factor and transforming growth factor-β2 can cause induction of retinal pigment epithelium cell-mediated collagen gel contraction in vitro via partial upregulation of α-smooth muscle actin expression.
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Immunohistochemical analysis of cellular adhesion molecules (ICAM-1, VCAM-1) and VEGF in fibrovascular membranes of patients with proliferative diabetic retinopathy: Preliminary study. ACTA ACUST UNITED AC 2009; 57:513-7. [DOI: 10.1016/j.patbio.2008.07.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Accepted: 07/03/2008] [Indexed: 11/17/2022]
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Abstract
Mast cells (MC) have been implicated in both normal and pathological angiogenesis, such as that in chronic inflammatory diseases and tumors. This assumption is partially supported by the close structural association between MC and blood vessels and the recruitment of these cells during tumor growth. MC release a number of angiogenic factors among which tryptase, a serine protease stored in MC granules, is one of the most active. In this study, we correlate the extent of angiogenesis with the number of tryptase-reactive MC in tissue fragments from pterygium and normal bulbar conjunctiva investigated by immunohistochemistry, using two murine monoclonal antibodies against the endothelial cell marker CD31 and the MC marker tryptase. Angiogenesis, measured as microvessel density, was highly correlated with MC tryptase-positive cell count in pterygium tissues. These results suggest that the characteristic neovascularization observed in pterygium may be sustained, at least in part, by MC angiogenic mediators, in particular tryptase.
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Angiogenesis in pterygium: study of microvessel density, vascular endothelial growth factor, and thrombospondin-1. Eye (Lond) 2006; 21:1095-101. [PMID: 16823458 DOI: 10.1038/sj.eye.6702495] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE This retrospective study aims to elucidate the role of angiogenesis in the pathogenesis of pterygium. We evaluated microvessel density (MVD), and expression of vascular endothelial growth factor (VEGF) and thrombospondin-1 (TSP-1). METHODS Fifty-two surgically excised pterygia and seven normal conjunctivae were immunohistochemically studied applying the streptavidin-biotin method in paraffin-embedded tissue sections. Monoclonal antibodies were targeted against CD31, VEGF, and TSP-1 proteins. RESULTS Pterygium presented with statistically significant higher average count of microvessels compared to normal conjunctivae (17.97+/-8.5 vs5.72+/-5 per high power field, P=0.001). In 24/52 (46.2%) cases of pterygium, high expression levels for VEGF were demonstrated, whereas the mean percentage of VEGF-positive epithelial cells was 58.03%. Furthermore, normal conjunctival presented statistically significant higher expression levels for VEGF in epithelial cells (83.14+/-36.08 vs58.03+/-31.23%, P=0.007). On the contrary, the presence of VEGF immunoreactivity in vascular endothelial and stromal cells was significantly higher in pterygium tissues (P<0.0001). Stromal staining for TSP-1 was detected in only 29/52 (55.8%) of the cases and no correlation with normal conjunctivae was found. Finally, statistically significant positive correlation between MVD values and stromal VEGF expression was found (P=0.049). CONCLUSION The angiogenesis-related factors that were studied proved to be highly expressed in pterygium tissue. On the contrary, TSP expression level was low, allowing inducers of angiogenesis to act uninhibited. This phenomenon could provide the pathogenic basis of pterygium formation.
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