Sema4D Knockout Attenuates Choroidal Neovascularization by Inhibiting M2 Macrophage Polarization Via Regulation of the RhoA/ROCK Pathway.

Purpose: The aim of this study was to elucidate the role of Sema4D in the pathogenesis of senescence-associated choroidal neovascularization (CNV) and to explore its underlying mechanisms. Methods: In this study, we utilized a model of laser-induced CNV in both young (3 months old) and old (18 months old) mice, including those with or without Sema4D knockout. The expression and localization of Sema4D in CNV were assessed using PCR, Western blot, and immunostaining. Subsequently, the morphological and imaging examinations were used to evaluate the size of CNV and vascular leakage. Finally, the expression of M2 markers, senescence-related markers, and molecules involved in the RhoA/ROCK pathway was detected. Results: We found that Sema4D was predominantly expressed in macrophages within CNV lesions, and both the mRNA and protein levels of Sema4D progressively increased following laser photocoagulation, a trend more pronounced in old mice. Moreover, Sema4D knockout markedly inhibited M2 polarization in senescent macrophages and reduced the size and leakage of CNV, particularly in aged mice. Mechanistically, aging was found to upregulate RhoA/ROCK signaling, and knockout of Sema4D effectively suppressed the activation of this pathway, with more significant effects observed in aged mice. Conclusions: Our findings revealed that the deletion of Sema4D markedly inhibited M2 macrophage polarization through the suppression of the RhoA/ROCK pathway, ultimately leading to the attenuation of senescence-associated CNV. These data indicate that targeting Sema4D could offer a promising approach for gene editing therapy in patients with neovascular age-related macular degeneration.

Acrizanib as a Novel Therapeutic Agent for Fundus Neovascularization via Inhibitory Phosphorylation of VEGFR2.

Purpose: The present study aimed to evaluate the effect of acrizanib, a small molecule inhibitor targeting vascular endothelial growth factor receptor 2 (VEGFR2), on physiological angiogenesis and pathological neovascularization in the eye and to explore the underlying molecular mechanisms. Methods: We investigated the potential role of acrizanib in physiological angiogenesis using C57BL/6J newborn mice, and pathological angiogenesis using the mouse oxygen-induced retinopathy (OIR) and laser-induced choroidal neovascularization (CNV) models. Moreover, vascular endothelial growth factor (VEGF)-treated human umbilical vein endothelial cells (HUVECs) were used as an in vitro model for studying the molecular mechanism underlying acrizanib's antiangiogenic effects. Results: The intravitreal injection of acrizanib did not show a considerable impact on physiological angiogenesis and retinal thickness, indicating a potentially favorable safety profile. In the mouse models of OIR and CNV, acrizanib showed promising results in reducing pathological neovascularization, inflammation, and vascular leakage, indicating its potential efficacy against pathological angiogenesis. Consistent with in vivo results, acrizanib blunted angiogenic events in VEGF-treated HUVECs such as proliferation, migration, and tube formation. Furthermore, acrizanib inhibited the multisite phosphorylation of VEGFR2 to varying degrees and the activation of its downstream signal pathways in VEGF-treated HUVECs. Conclusions: This study suggested the potential efficacy and safety of acrizanib in suppressing fundus neovascularization. Acrizanib functioned through inhibiting multiple phosphorylation sites of VEGFR2 in endothelial cells to different degrees. Translational Relevance: These results indicated that acrizanib might hold promise as a potential candidate for the treatment of ocular vascular diseases.

Therapeutic Benefit of Melatonin in Choroidal Neovascularization During Aging Through the Regulation of Senescent Macrophage/Microglia Polarization.

Purpose: This study aimed to investigate the age-dependent anti-angiogenic capability of melatonin in choroidal neovascularization (CNV) and to explore the underlying molecular mechanisms. Methods: In the present study, a laser-induced CNV model was established in both young (three months of age) and old (18 months of age) mice, and the size of CNV lesions and vascular leakage was detected by morphological and imaging examination. Next, Western blot and immunostaining were used to observe the levels of M2 markers, senescence-related markers, and molecules involved in IL-10/STAT3 pathway. Additionally, colivelin was used to study the effect of IL-10/STAT3 pathway activation on the expression of M2 markers and senescence-related markers by Western blot and immunostaining. Finally, the effects of colivelin on melatonin-induced reduction of CNV size and vascular leakage in mice at different ages were assessed using morphological and imaging examination. Results: Our results revealed that aging promoted M2 macrophage/microglia polarization, and aggravated CNV and vascular leakage. Melatonin significantly inhibited the M2 polarization of senescent macrophage/microglia and reduced the CNV area and vascular leakage. Moreover, melatonin markedly suppressed IL-10/STAT3 pathway activation in the macrophage/microglia of old mice, and STAT3 activator colivelin reversed the suppressive effect of melatonin on M2 polarization of senescent macrophage/microglia and laser-induced CNV in old mice. Conclusions: Our data demonstrated that melatonin significantly prevented the M2 polarization of senescent macrophage/microglia by inhibiting the IL-10/STAT3 pathway, and eventually attenuated senescence-associated CNV. These findings suggested that melatonin could serve as a promising therapeutic agent to treat CNV and other age-related ocular diseases.

miR-429 negatively regulates the progression of hypoxia-induced retinal neovascularization by the HPSE-VEGF pathway.

Heparanase (HPSE) and vascular endothelial growth factor (VEGF) are believed to play a vital role in hypoxia-induced retinal neovascularization (RNV). HPSE is a target gene of miR-429. Our study aimed to investigate the effect of the miR-429-HPSE-VEGF pathway on hypoxia-induced RNV. The gene and protein expression of miR-429, HPSE and VEGF in human retinal endothelial cells and retinas was determined by real-time PCR and Western blot assays. The effects of miR-429 on human retinal endothelial cells and retinal neovascularization under hypoxia condition were verified by in vitro and in vivo experiments. First, we studied the effect of the miR-429-HPSE-VEGF pathway in HRECs under hypoxic conditions. HREC functions such as migration and tube formation were enhanced under hypoxic conditions. Overexpression of miR-429 in HRECs reversed these changes. Then, we investigated the effect of miR-429 on hypoxia-induced RNV in vivo. When miR-429 agomirs were injected into the vitreous cavity of mice with oxygen-induced retinopathy to overexpress miR-429, the mRNA and protein expression of VEGF was significantly reduced. In addition, indicators of retinal neovascularization, such as the retinal avascular area, and morphology of vessels, were reduced significantly in the miR-429 overexpression group. In this study, our data showed that miR-429 plays an important role by inhibiting the HPSE-VEGF pathway in hypoxia-induced retinopathy.

Oxidative stress-induced KLF4 activates inflammatory response through IL17RA and its downstream targets in retinal pigment epithelial cells.

Age-related macular degeneration (AMD) is a leading cause of irreversible blindness worldwide. Oxidative stress (OS), inflammation and genetics are considered the key pathogenic factors contributing to AMD development. Recent evidence shows the pro-inflammatory interleukin 17 (IL17) signaling is activated in AMD patients and promotes disease pathogenesis. However, the interplay between OS and IL17 signaling, and the regulatory mechanism of IL17 pathway are largely unknown. OS-induced retinal pigment epithelial cell (RPE) damage causes both the initial pathogenesis of AMD and secondary degeneration of rods and cones. Healthy RPE is essential for ocular immune privilege, however, damaged RPE cells can activate inflammatory response. In the present study, we identified IL17RA, the principle receptor of IL17 signaling, is one of the most upregulated inflammatory genes in human RPE cells upon OS exposure. The prominent increase of IL17RA was also observed in RPE and retina of an AMD-like mouse model. Knockdown of IL17RA in RPE cells prevented OS-induced RPE cell apoptosis and reduced the inflammatory response in both RPE and macrophages. Furthermore, we found that transcription factor KLF4 directly activates IL17RA expression, therefore, promotes the production of IL1ß and IL8 in an IL17RA-dependent manner. In addition, the mRNA level of KLF4 isoform 2 was positively correlated with that of IL17RA in AMD patients. Together, our study demonstrates an unrevealed relationship between IL17RA and OS, and a new regulatory mechanism of IL17RA by KLF4 in RPE cells. These findings suggest that inhibition of IL17RA as a new potential therapeutic target for AMD through RPE protection and inflammatory suppression upon OS exposure.

Comparison between non-visualized polyps and visualized polyps on optical coherence tomography angiography in polypoidal choroidal vasculopathy.

PURPOSE: To determine the underlying reasons for the non-visualization of polyps on en face optical coherence tomography angiography (OCTA) in patients with polypoidal choroidal vasculopathy (PCV). METHODS: A cross-sectional study of consecutive treatment-naïve 30 eyes with active PCV was included. Results of fundus photography, fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), spectral domain optical coherence tomography (SD-OCT), and en face OCTA were analyzed. RESULTS: A total of 64 active polyps were found on FFA and ICGA in 30 eyes. On OCTA, 42/64 (65.6%) polyps were visualized, while 22/64 (34.4%) polyps were non-visualized. There were no significant differences in the size (P = 0.723) and filling time of polyps (P = 0.558) between the two groups. However, polypoidal lesions were less common in the non-visualized group (P < 0.001). The height of the polyps on SD-OCT was 243.95 ± 114.24 µm in the non-visualized group, which was higher than those (188.00 ± 87.93 µm) in the visualized group (P = 0.048). Moreover, more pulsatile polyps (72.7%) were found in the non-visualized group than those (2.4%) in the visualized group (P < 0.001). Four of the 22 polyps in the non-visualized group (18.2%) were located under a thick subretinal hemorrhage, and two of 22 invisible polyps (9.6%) located under and parallel to the retinal vessel in the inner layer of retina. CONCLUSIONS: Our results revealed that the height of the polyps, and not the size and pulsation of the polyps, correlated with the visualization of the polyps on OCTA. Polyps that were pulsating in early ICGA were difficult to be visualized on OCTA, which is the most possible reason for the non-visualization. Coverage with thick subretinal hemorrhage or retina vessels was another reason for the non-visualization of the polyps in active PCV on OCTA.

Combinatorial treatment with topical NSAIDs and anti-VEGF for age-related macular degeneration, a meta-analysis.

Inflammation is a key pathogenic factor in age-related macular degeneration (AMD). However, the clinical importance of combining anti-VEGF agents and topical NSAIDs to reduce inflammation remains unclear. In this study, we systematically reviewed clinical trials comparing combined treatment versus anti-VEGF alone in AMD patients. We quantified treatment effects via meta-analysis. The pooled weighted mean difference (WMD, -0.91, 95%CI: -1.39 to -0.42, P = 0.0003) demonstrates that combined treatment may reduce required anti-VEGF injection number, probably by means of decreasing central retina thickness (CRT) (WMD = -22.9, 95% CI: -41.20 to -4.59, P = 0.01). The best corrected visual acuity (BCVA) did not change significantly between these two groups (WMD = - 0.01, 95%CI: -0.23 to 0.20, P = 0.90). Topical NSAIDs slightly increased the incidence of foreign body sensation (Odds Ratio [OR] = 2.63, 95%Cl: 1.06 to 6.52, P = 0.76). Combining topical NSAIDs and anti-VEGF agents may provide a new strategy for AMD treatment.

Macrophage polarization in experimental and clinical choroidal neovascularization.

Macrophages play an important role in the development of age-related macular degeneration (AMD). In this study, the spatial and temporal changes and the polarization of macrophages in murine laser-induced choroidal neovascularization (CNV) were investigated, and the polarized M1 and M2 biomarkers in the aqueous humors of neovascular AMD (nAMD) patients were studied. Macrophages, the main infiltrating inflammatory cells in CNV lesions, were evidenced by a significant increase in F4/80 mRNA expression and by the infiltration of F4/80+ cells in the lesions and the vicinity of laser-induced CNV. The mRNA expressions of M1-related markers were dramatically upregulated in the early stage, while the M2-related markers were slightly upregulated in the middle stage and sustained until the late stage. The results of immunostaining showed a similar early-but-transient M1 pattern and a delayed-but-sustained M2 pattern in laser-induced CNV. In addition, a higher M2/M1 ratio was found in both the murine models (Arg-1/iNOS and CCL22/CXCL10) and the aqueous humors of nAMD patients (CCL22/CXCL10) than in the controls. Our results suggested that the dynamic patterns of M1 and M2 were different in both the experimental and clinical CNV. The M2 macrophages were predominant and may play a more important role in the development of CNV.

Aqueous humor cytokine profiling in patients with wet AMD.

PURPOSE: To investigate the chemokine expression profiles in the aqueous humor of wet age-related macular degeneration (wet AMD) patients and to correlate their levels with clinical findings. METHODS: Undiluted aqueous humor samples (100-200 µl) were obtained from 16 wet AMD eyes and 12 control eyes. Forty chemokines were measured using a multiplex method. A 6×6 mm area of the macular region centered on the fovea was examined using spectral domain optical coherence tomography (SD-OCT). RESULTS: The detection rates were 50% or more for 15 chemokines. Compared with the control group, the aqueous humor in wet AMD patients showed a significantly higher expression of CXCL10 (p=0.004), CCL14 (p=0.002), CXCL16 (p=0.013), CXCL7 (p=0.033), and CCL22 (p=0.037), while growth-related oncogene (GRO) was significantly decreased in the wet AMD patients (p=0.001). When compared with treatment-naïve patients, the recurrent group had significant upregulation of CXCL10 (p=0.012) and CCL22 (p=0.002). CXCL16 was positively correlated with lesion size, and CCL22 was higher in patients whose OCT images showed intraretinal fluid (IRF) or hyperreflective foci (HF). CONCLUSIONS: Elevated levels of inflammation-related chemokines, including CXCL10, CCL14, CXCL16, CXCL7, and CCL22, in the aqueous humor of AMD patients may suggest a pathogenic role for inflammation. CXCL10 and CCL22 were more elevated in eyes with recurrent wet AMD than in treatment-naïve eyes. CXCL16 was positively correlated with lesion size. The increase in CCL22 was correlated with the presence of IRF or HF. These data may be of interest in the search for biomarkers associated with wet AMD and may potentially indicate different treatment strategies.

Combined Persistent Fetal Vasculature: A Classification Based on High-Resolution B-Mode Ultrasound and Color Doppler Imaging.

PURPOSE: The purpose of this study was to classify combined persistent fetal vasculature (PFV) on the basis of the ultrasonographic and Doppler characteristics. The potential clinical significance for both surgery design and prognosis determination was discussed. DESIGN: A cross-sectional case series. PARTICIPANTS: The eyes of 54 children diagnosed with unilateral combined PFV were evaluated using B-mode ultrasound and color Doppler imaging (CDI). METHODS: Each participant's age at first presentation, diagnosis for referral, gender, family history, and systemic or other ocular anomalies were recorded. Retinal detachment, optic nerve abnormalities, and macular dislocation were also recorded in detail according to the RetCam (Clarity Medical Systems, Pleasanton, CA), ultrasound, and Doppler findings. The PFV eyes were divided into 4 groups on the basis of the ultrasound and CDI findings. Intergroup analysis was performed. MAIN OUTCOME MEASURES: Overall and intergroup analyses of the demographic features of the children with PFV were performed. The axial length, depth of the anterior chamber, and lens thickness were compared between the affected eyes and the fellow healthy eyes among the 4 groups. RESULTS: Some 22.2%, 18.5%, 33.3%, and 25.9% of the eyes were grouped into type I ("I" shape), II ("Y" shape), III (inverted "Y" shape), and IV ("X" shape) combined PFV, respectively. The age at first presentation for type I was older than that for the other groups (P = 0.014). The axial length was reduced (P = 0.012) and the anterior chamber more shallow (P = 0.011) than in fellow healthy eyes for type IV eyes, but not for the other 3 groups. CONCLUSIONS: Ultrasound and CDI are informative screening and diagnostic tools that show characteristic flow patterns in the 4 types of combined PFV. This novel classification system provides new and important information for the diagnosis of PFV and, if validated, may play a role in guiding treatment recommendations in the future.

Interleukin-4 and melatonin ameliorate high glucose and interleukin-1ß stimulated inflammatory reaction in human retinal endothelial cells and retinal pigment epithelial cells.

PURPOSE: We aimed to evaluate the effects of two immune regulatory factors, interleukin-4 (IL-4) and melatonin, on several inflammatory mediators that are involved in inflammation and angiogenesis in diabetic retinopathy (DR), in high glucose or interleukin-1ß (IL-1ß) induced primary human retinal endothelial cells (RECs) and human retinal pigment epithelial (RPE) cells. METHODS: Human RECs and RPE cells were cultured in 30 mM D-glucose or 10 ng/ml IL-1ß, with or without the presence of 40 ng/ml IL-4 or 100 µM melatonin. The mRNA and protein levels of vascular endothelial growth factor (VEGF), intercellular cell adhesion molecule-1 (ICAM-1), matrix metalloproteinases 2 (MMP2), and matrix metalloproteinases 9 (MMP9) were measured using real-time PCR and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS: High glucose and IL-1ß induced the expression of VEGF, ICAM-1, MMP2, and MMP9 in human RECs and RPE cells. IL-4 and melatonin downregulated the expression of VEGF, ICAM-1, MMP2, and MMP9 induced by high glucose and IL-1ß. CONCLUSIONS: Our results demonstrated that IL-4 and melatonin inhibited inflammation and angiogenesis triggered by high glucose and IL-1ß, which suggests that these immune regulatory factors may be of potential therapeutic value in DR.

Limbal allografting from living-related donors to treat partial limbal deficiency secondary to ocular chemical burns.

OBJECTIVE: To evaluate outcomes of limbal allograft transplantation from living-related donors to treat partial limbal deficiency secondary to ocular chemical burns. METHODS: Retrospective noncomparative case series comprising 17 patients (17 eyes) with partial limbal deficiency (≤50%) secondary to ocular alkali burns (11 eyes) or acid burns (6 eyes). Recipient eyes were treated by removing the conjunctivalized pannus. Superior limbal grafts (mean length, 3-5 clock hours) from HLA antigen-matched living-related donors were transplanted into deficient areas of recipient eyes. No recipients received systemic cyclosporin A therapy. Main outcome measures included corneal reepithelialization, reduction in vascularity, improved corneal clarity, and best-corrected visual acuity. RESULTS: All eyes achieved epithelialization a mean (SD) of 10.1 (1.9) days after surgery. Corneal reepithelialization, reduction in vascularity, and improved corneal opacity were seen in all eyes. No eyes demonstrated recurrent epithelial defects or fibrovascular tissue, but gradual recurrence of peripheral corneal vascularization was observed in 7 eyes during the follow-up period. Allograft rejection developed in 3 eyes (17.6%), all of which were successfully treated. Best-corrected visual acuity improved in all eyes, and 10 eyes (58.8%) had achieved best-corrected visual acuity of 0.5 or better (≥20/10 Snellen) at the last follow-up visit. CONCLUSIONS: Transplantation of limbal tissue from live-related donors successfully reconstructed the ocular surface. Long-term graft survival in patients with partial limbal deficiency secondary to ocular chemical burns can be accomplished without the use of systemic immunosuppression.

KH906, a recombinant human VEGF receptor fusion protein, is a new effective topical treatment for corneal neovascularization.

PURPOSE: The purpose of the current study was to investigate the effect of topical administration of KH906 on corneal neovascularization (NV). METHODS: To induce corneal neovascularization, chemical cauterization of the corneas of the right eyes of forty-eight New Zealand white rabbits was performed by touching the central cornea with an 8-mm-diameter NaOH-soaked Whatman filter paper for 60 s. On the next day after modeling, the rabbits were randomly and equally divided into six groups: PBS control group, 0.1% dexamethasone group, 10 mg/ml Avastin group, 5 mg/ml KH906 group, 10 mg/ml KH906 group, and 20 mg/ml KH906 group. The rabbits in the six groups received topical administration of 50 µl of the different solutions on the cornea four times per day for 14 days. Corneal neovascularization was analyzed by slit-lamp biomicroscopy 10 and 14 days after chemical cauterization. Corneal fluorescein staining was performed to evaluate the extent of corneal epithelial defect on the 7th, 10th, and 14th days. The VEGF level of the cornea was evaluated by ELISA assay. RESULTS: On the 10th and 14th days after chemical cauterization, the length of the longest new vessel and the areas of corneal neovascularization in all KH906-treated groups were significantly reduced compared to those of the PBS-treated group (p<0.05). The VEGF level of the cornea in all KH906-treated groups was significantly decreased compared to that of the PBS-treated group (p<0.05). Corneal fluorescein staining showed that KH906 had no effect on corneal epithelial healing. CONCLUSIONS: Topical administration of KH906 significantly inhibited alkali burn-induced corneal neovascularization in rabbits. The new eye drops of KH906 may have a broad application for human corneal neovascularization in the near future.

Descemet's stripping with endothelial keratoplasty for special Fuchs' endothelial dystrophy in phakic eyes.

BACKGROUND: To determine the efficacy and postoperative complications of simple Descemet's stripping endothelial keratoplasty (DSEK) for treatment of special Fuchs' endothelial dystrophy in phakic eyes. METHODS: Six eyes with clear crystalline lenses in 5 consecutive patients with Fuchs' endothelial dystrophy underwent DSEK and were followed up for 12-27 months. The pupil was constricted preoperatively to 1.5 mm in diameter. The anterior chamber was deepened intraoperatively by injection of balanced salt solution to unfold the donor graft and to protect the crystalline lens. Best corrected visual acuity, corneal astigmatism, corneal curvature, corneal thickness, and anterior chamber depth were recorded preoperatively and at 6 and 12 months postoperatively. Average endothelial cell density and endothelial cell loss (ECL) were recorded at 6 and 12 months postoperatively. RESULTS: DSEK was successfully performed in all 6 eyes. No graft dislocation or lens injury occurred. One of the 6 eyes presented with mild cataract at 12 months after surgery but showed no sign of progressive cataract development during the follow-up. All grafts were clear during the last follow-up: best corrected visual acuity ranged from 20/50 to 20/30, average corneal astigmatism was 2.2 ± 0.6 dpt, average corneal curvature was 46.0 ± 2.4 dpt, and average central corneal thickness was 583.0 ± 21.5 µm. At 6 and 12 months postoperatively, average endothelial cell density was 2,070.7 ± 206.1 cells/mm(2) (28.0 ± 7.5% of ECL) and 1,838.3 ± 194.5 cells/mm(2) (36.1 ± 6.2% of ECL), respectively. CONCLUSIONS: Simple DSEK might be a feasible option for Fuchs' endothelial dystrophy in young patients with clear crystalline lenses.