Adhesion failures determine the pattern of choroidal neovascularization in the eye: a computer simulation study.
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ABSTRACT:
SUBMITTER: Shirinifard A
PROVIDER: S-EPMC3342931 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:We present a computer simulation and associated experimental validation of assembly of glial-like support cells into the interweaving hexagonal lattice that spans the Drosophila pupal eye. This process of cell movements organizes the ommatidial array into a functional pattern. Unlike earlier simulations that focused on the arrangements of cells within individual ommatidia, here we examine the local movements that lead to large-scale organization of the emerging eye field. Simulations based on our experimental observations of cell adhesion, cell death, and cell movement successfully patterned a tracing of an emerging wild-type pupal eye. Surprisingly, altering cell adhesion had only a mild effect on patterning, contradicting our previous hypothesis that the patterning was primarily the result of preferential adhesion between IRM-class surface proteins. Instead, our simulations highlighted the importance of programmed cell death (PCD) as well as a previously unappreciated variable: the expansion of cells' apical surface areas, which promoted rearrangement of neighboring cells. We tested this prediction experimentally by preventing expansion in the apical area of individual cells: patterning was disrupted in a manner predicted by our simulations. Our work demonstrates the value of combining computer simulation with in vivo experiments to uncover novel mechanisms that are perpetuated throughout the eye field. It also demonstrates the utility of the Glazier-Graner-Hogeweg model (GGH) for modeling the links between local cellular interactions and emergent properties of developing epithelia as well as predicting unanticipated results in vivo.
| S-EPMC2895643 | biostudies-literature
Project description:OBJECTIVE:To determine whether home monitoring with the ForeseeHome device (Notal Vision Ltd, Tel Aviv, Israel), using macular visual field testing with hyperacuity techniques and telemonitoring, results in earlier detection of age-related macular degeneration-associated choroidal neovascularization (CNV), reflected in better visual acuity, when compared with standard care. The main predictor of treatment outcome from anti-vascular endothelial growth factor (VEGF) agents is the visual acuity at the time of CNV treatment. DESIGN:Unmasked, controlled, randomized clinical trial. PARTICIPANTS:One thousand nine hundred and seventy participants 53 to 90 years of age at high risk of CNV developing were screened. Of these, 1520 participants with a mean age of 72.5 years were enrolled in the Home Monitoring of the Eye study at 44 Age-Related Eye Disease Study 2 clinical centers. INTERVENTIONS:In the standard care and device arms arm, investigator-specific instructions were provided for self-monitoring vision at home followed by report of new symptoms to the clinic. In the device arm, the device was provided with recommendations for daily testing. The device monitoring center received test results and reported changes to the clinical centers, which contacted participants for examination. MAIN OUTCOME MEASURES:The main outcome measure was the difference in best-corrected visual acuity scores between baseline and detection of CNV. The event was determined by investigators based on clinical examination, color fundus photography, fluorescein angiography, and optical coherence tomography findings. Masked graders at a central reading center evaluated the images using standardized protocols. RESULTS:Seven hundred sixty-three participants were randomized to device monitoring and 757 participants were randomized to standard care and were followed up for a mean of 1.4 years between July 2010 and April 2013. At the prespecified interim analysis, 82 participants progressed to CNV, 51 in the device arm and 31 in the standard care arm. The primary analysis achieved statistical significance, with the participants in the device arm demonstrating a smaller decline in visual acuity with fewer letters lost from baseline to CNV detection (median, -4 letters; interquartile range [IQR], -11.0 to -1.0 letters) compared with standard care (median, -9 letters; IQR, -14.0 to -4.0 letters; P = 0.021), resulting in better visual acuity at CNV detection in the device arm. The Data and Safety Monitoring Committee recommended early study termination for efficacy. CONCLUSIONS:Persons at high risk for CNV developing benefit from the home monitoring strategy for earlier detection of CNV development, which increases the likelihood of better visual acuity results after intravitreal anti-VEGF therapy.
| S-EPMC3918479 | biostudies-literature
Project description:Perturbations in WNT signaling are associated with congenital eye disorders, including familial exudative vitreoretinopathy and Norrie disease. More recently, activation of the WNT pathway has also been shown to be associated with age-related macular degeneration (AMD). In this study, we identified that in choroidal neovascular membranes from AMD patients, ?-catenin is activated specifically in the vascular endothelium, suggesting that WNT promotes pathologic angiogenesis by directly affecting vascular endothelial cells. WNT7B has been shown to be important during eye development for regression of the fetal hyaloid vasculature. However, it has not yet been established whether WNT7A and/or WNT7B are involved in neovascular AMD pathogenesis. Here, we show that WNT7A and WNT7B increase the proliferation of human dermal microvascular endothelial cells in a dose-dependent manner. Both WNT7A and WNT7B also stimulated vascular sprouting from mouse choroidal explants in vitro. To evaluate in vivo relevance, we generated mice systemically deficient in Wnt7a and/or Wnt7b. Genetic deletion of both Wnt7a and Wnt7b decreased the severity of laser injury-induced choroidal neovascularization (CNV), while individual deletion of either Wnt7a or Wnt7b did not have a significant effect on CNV, suggesting that WNT7A and WNT7B have redundant pro-angiogenic roles in vivo. Cumulatively, these findings identify specific WNT isoforms that may play a pathologic role in CNV as observed in patients with neovascular AMD. Although the source of increased WNT7A and/or WNT7B in CNV requires further investigation, WNT signaling may be a potential target for therapeutic intervention if these results are demonstrated to be relevant in human disease.
| S-EPMC6110966 | biostudies-literature
Project description:In the severity of myocardial infarction, Toll-like receptor (TLR) 9 plays a pivotal role in the inflammatory responses induced through damage-associated molecular patterns involving mitochondrial DNA and HMGB1. However, the therapeutic agents currently available for myocardial infarction substantially lack any association with the effects on immune responses. In this study, we applied a comprehensive drug discovery approach, which integrates in silico, in vitro, and in vivo processes, as well as determined therapeutic effects and mechanisms free from side effects. In an animal model of myocardial infarction, conditioned based on pharmacological properties, improved effects compared to the FDA-approved Rosuvastatin were detected. In summary, a small molecular inhibitor, ETA53 (endosomal Toll-like receptor antagonist 53), which selectively acts on TLR9 in nano-molar units, was developed. ETA53 was found to be effective for treating myocardial infarction caused by permanent ligation of the left anterior descending coronary artery, based on indicators such as cardiac function, inflammation, infarct size, and fibrosis. The results offered insights that varied from those of conventional drug development perspectives; consequently, the novel inhibitor may provide an alternative treatment with a mechanism different from that of the commercially available drugs for myocardial infarction.
2023-11-12 | GSE247311 | GEO
Project description:PURPOSE:Doxycycline, a broad-spectrum antibiotic, has certain antiangiogenic properties and can inhibit matrix metalloproteinases (MMPs/gelatinases). The authors investigated the effects of doxycycline on choroidal neovascularization (CNV) and regulation of MMP-2 and -9 and pigment epithelium-derived factor (PEDF). METHODS:Doxycycline was orally administered to rats at 500, 50, 5, and 0.5 mg/kg/d; nontreated animals were used as controls. Experimental CNV was induced with laser 7 days after doxycycline treatment started. At 7 days after induction, animals were euthanatized, and eyes were collected. RPE/choroid flatmounts were labeled with isolectin IB4 to determine CNV lesion volumes using confocal microscopy and high-performance 3D imaging software. MMP-2, MMP-9, and PEDF protein levels were determined by ELISA. MMP catalytic activity was determined in solution using fluorogenic gelatin and peptide substrates, by gelatin zymography in SDS-PAGE, and by in situ fluorogenic substrate zymography in RPE/choroid sections. RESULTS:CNV complex lesion volumes decreased with doxycycline in a dose-response relationship. A dosage of 500 mg/kg/d caused a 70% inhibition of CNV complex volume compared with control animals. Doxycycline elevated PEDF levels in plasma and did not affect the active and pro-enzymes MMP-2 and MMP-9 levels. However, the in vitro enzymatic activities of purified MMP-2 and MMP-9 declined significantly with doxycycline. MMP-2, MMP-9, and gelatinolytic activities in situ increased early in CNV lesion development. Doxycycline treatments and exogenous additions inhibited gelatinolytic activities in CNV lesions. CONCLUSIONS:Doxycycline effectively hampered the progression of experimental CNV. The results suggest that orally administrated doxycycline can reach the choroid to attenuate proteolytic enzymes that remodel Bruch's membrane and promote the antiangiogenic PEDF to inhibit neovascularization.
| S-EPMC2836119 | biostudies-literature
Project description:Many conditions affecting the heart, brain, and even the eyes have their origins in blood vessel pathology, underscoring the role of vascular regulation. In age-related macular degeneration (AMD), there is excessive growth of abnormal blood vessels in the eye (choroidal neovascularization), eventually leading to vision loss due to detachment of retinal pigmented epithelium. As the advanced stage of this disease involves loss of retinal pigmented epithelium, much less attention has been given to early vascular events such as endothelial dysfunction. Although current gold standard therapy using inhibitors of vascular endothelial growth factor (VEGF) have achieved initial successes, some drawbacks include the lack of long-term restoration of visual acuity, as well as a subset of the patients being refractory to existing treatment, alluding us and others to hypothesize upon VEGF-independent mechanisms. Against this backdrop, we present here a nonexhaustive review on the vascular underpinnings of AMD, implications with genetic and systemic factors, experimental models for studying choroidal neovascularization, and interestingly, on both endothelial-centric pathways and noncell autonomous mechanisms. We hope to shed light on future research directions in improving vascular function in ocular disorders.
| S-EPMC6895252 | biostudies-literature
Project description:BackgroundAge-related degeneration (AMD) and asthma are both diseases that are related to the activation of the complement system. The association between AMD and asthma has been debated in previous studies. The authors investigated the relationship between AMD and asthma systemically.Principal findingsThe epidemiological study showed that asthma was related to choroidal neovascularization (CNV) subtype (OR?=?1.721, P?=?0.023). However, the meta-analysis showed there was no association between AMD and asthma. In an animal model, we found more fluoresce in leakage of CNV lesions by FA analysis and more angiogenesis by histological analysis in rats with asthma. Western blot demonstrated an elevated level of C3?-chain, C3?'-chain and VEGF. After compstatin was intravitreally injected, CNV leakage decreased according to FA analysis, with the level of C3 and VEGF protein decreasing at the same time.SignificanceThis study first investigated the relationship between AMD and asthma systematically, and it was found that asthma could be a risk factor for the development of AMD. The study may provide a better understanding of the disease, which may advance the potential for screening asthma patients in clinical practice.
| S-EPMC3342271 | biostudies-literature
Project description:The purpose of this study was to evaluate the potential benefits of intravitreal aflibercept injections for the treatment of choroidal neovascularization (CNV) secondary to chorioretinitis.In this uncontrolled, prospective cohort study, 15 eyes of 14 consecutive patients affected by CNV associated with ocular toxoplasmosis were treated with intravitreal aflibercept (2 mg) pro re nata and observed over a 12-month follow-up period. The primary outcome was the change in best-corrected visual acuity (BCVA) from baseline to month 12. Secondary outcomes included change in central retinal thickness (CRT) in the foveal area on optical coherence tomography (OCT) from baseline to month 12, the number of intravitreal aflibercept injections administered, and safety.Mean (standard deviation [SD]) BCVA improved significantly from 0.36 (0.23) at baseline to 0.64 (0.3) at month 12 (P=0.0002). Mean (SD) CRT on OCT showed a reduction from 317 (74) µm at baseline to 254 (43) µm (P=0.0002) at month 12. A mean (SD) of 1.7 (0.5) injections (range, 1-2 injections) were performed during the study period. No cases of endophthalmitis, uveitis, stroke, or retinal detachment were noted. No patient demonstrated an intraocular pressure >20 mmHg at any study visit.Intravitreal aflibercept showed a positive clinical effect and was well tolerated for the treatment of CNV associated with chorioretinitis. The results could be helpful for selecting a treatment for CNV secondary to chorioretinitis.
| S-EPMC5533470 | biostudies-other
Project description:ObjectiveTo assess the influence of drug; dosing regimen; and traditional, nontraditional, and genetic risk factors on the incidence of choroidal neovascularization (CNV) in the fellow eye of patients treated for CNV with ranibizumab or bevacizumab.DesignCohort study of patients enrolled in a multicenter, randomized clinical trial.ParticipantsPatients with no CNV in the fellow eye at the time of enrollment in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT).MethodsEligibility criteria for the clinical trial required that study eyes have evidence on fluorescein angiography and optical coherence tomography of CNV secondary to age-related macular degeneration (AMD) and visual acuity between 20/25 and 20/320. Treatment for the study eye was assigned randomly to either ranibizumab or bevacizumab and to 3 different regimens for dosing over a 2-year period. The genotypes for 4 single nucleotide polymorphisms (SNPs) associated with risk of AMD were determined. Only patients without CNV in the fellow eye at baseline were considered at risk. The CATT ophthalmologists examined patients every 4 weeks through 2 years and recorded treatment for CNV in the fellow eye.Main outcome measuresDevelopment of CNV in the fellow eye.ResultsAmong 1185 CATT participants, 727 (61%) had no CNV in the fellow eye at enrollment. At 2 years, CNV had developed in 75 (20.6%) of 365 patients treated with ranibizumab and in 60 (16.6%) of 362 patients treated with bevacizumab (absolute difference, 4.0%; 95% confidence interval [CI], -1.7% to 9.6%; P = 0.17). The risk ratio for pro re nata dosing relative to monthly dosing was 1.1 (95% CI, 0.8-1.6). Greater elevation of the retinal pigment epithelium and fluid in the foveal center of the study eye were associated with increased incidence of CNV in the fellow eye. Incidence was not associated with genotype on rs1061170 (CFH), rs10490924 (ARMS2), rs11200638 (HTRA1), and rs2230199 (C3; P>0.35).ConclusionsThrough 2 years, there was no statistically significant difference between ranibizumab and bevacizumab in incidence of CNV in the fellow eye. Genotype on 4 SNPs previously found to be associated with AMD did not affect the risk of CNV in the fellow eye among CATT patients.Financial disclosure(s)Proprietary or commercial disclosure may be found after the references.
| S-EPMC3758381 | biostudies-literature
Project description:ImportanceA hemodynamic role in the pathogenesis of age-related macular degeneration (AMD) has been proposed, but to our knowledge, an association between retinal vasculature and late AMD has not been investigated.ObjectiveTo determine whether the presence and location of a cilioretinal artery may be associated with the risk of late AMD in the Age-Related Eye Disease Study (AREDS).Design, setting, and participantsRetrospective analysis of prospective, randomized clinical trial data from 3647 AREDS participants. Fundus photographs of AREDS participants were reviewed by 2 masked graders for the presence or absence of a cilioretinal artery and whether any branch extended within 500 μm of the central macula. Multivariate regressions were used to determine the association of the cilioretinal artery and vessel location, adjusted for age, sex, and smoking status, with the prevalence of choroidal neovascularization (CNV) or central geographic atrophy (CGA) and AMD severity score for eyes at randomization and progression at 5 years.Main outcomes and measuresAssociation of cilioretinal artery with prevalence and 5-year incidence of CNV or CGA.ResultsAmong AREDS participants analyzed, mean (SD) age was 69.0 (5.0) years, with 56.3% female, 46.6% former smokers, and 6.9% current smokers. A total of 26.9% of patients had a cilioretinal artery in 1 eye, and 8.4% had the vessel bilaterally. At randomization, eyes with a cilioretinal artery had a lower prevalence of CNV (5.0% vs 7.6%; OR, 0.66; 95% CI, 0.51-0.85; P = .001) but no difference in CGA (1.1% vs 0.8%; OR, 1.33; 95% CI, 0.76-2.32; P = .31). In eyes without late AMD, those with a cilioretinal artery also had a lower mean (SD) AMD severity score (3.00 [2.35] vs 3.19 [2.40]; P = .02). At 5 years, eyes at risk with a cilioretinal artery had lower rates of progression to CNV (4.1% vs 5.5%; OR, 0.75; 95% CI, 0.56-1.00; P = .05) but no difference in developing CGA (2.2% vs 2.7%; OR, 0.83; 95% CI, 0.56-1.23; P = .35) or change in AMD severity score (0.65 [1.55] vs 0.73 [1.70]; P = .11). In patients with a unilateral cilioretinal artery, eyes with the vessel showed a lower prevalence of CNV than fellow eyes (4.7% vs 7.2%; P = .01).Conclusions and relevanceThe presence of a cilioretinal artery is associated with a lower risk of developing CNV, but not CGA, suggesting a possible retinal hemodynamic contribution to the pathogenesis of neovascular AMD.Trial registrationClinicalTrials.gov Identifier: NCT00000145.
| S-EPMC6142983 | biostudies-literature