角膜新生血管中细胞与分子的研究进展

多种眼部损伤可诱导角膜新生血管形成,促进疾病发展,造成角膜水肿、视力受损,甚至失明,因此抑制角膜新生血管有助于延缓疾病进程并降低角膜损伤,具有十分重要的临床意义。本文将对参与角膜新生血管形成的细胞及分子作最新的系统论述,并分析可能的抑制靶点,以期为科研及临床提供参考。     

Inhibition of corneal neovascularization by topical application of nintedanib in rabbit models

AIM: To evaluate the potential efficacy and mechanisms of nintedanib in corneal neovascularization (NV) in rabbit models. METHODS: Corneal NV was induced using 1 mol/L NaOH. Rabbits (n=21) were randomized to 3 groups: Group 1 were treated with 0.9% NaCl, Group 2 with Avastin (5 mg/mL), and Group 3 with nintedanib (1 mg/mL). All treatments started 1d after alkaline burns and were topically performed 3 times a day for 2wk. Photographs were taken on a slit lamp microscope on day 7 and 14. The NV area, the length of the vascularization and angiogenesis index (AI) were used to evaluate the corneal NV. On day 14, the immunohistochemical (IHC) studies of the cornea were examined. Western blot was performed to test the expression levels of vascular endothelial growth factor (VEGF), Akt, p-Akt, P38, p-P38, MMP-2 and MMP-9. RESULTS: The corneal NV area, vessel length and AI in Group 3 were significantly lower than Group 2, with both being lower than Group 1. IHC staining showed that VEGF was significantly overexpressed in the epithelium and stroma of cornea following alkaline burns. In contrast, the level of VEGF was significantly suppressed in both Group 2 and Group 3. Western blot results further confirmed that, compared with Group 1, Group 3 had significantly reduced expressions of VEGF, Akt, p-Akt, p-P38, MMP-2, and MMP-9 in corneal tissues. Trends of lower levels of MMP-2, AKT, and p-AKT in Group 3 than Group 2 were identified. CONCLUSION: Nintedanib and Avastin can effectively inhibit corneal NV, with P38 MAPK and AKT signaling pathways being possibly involved. Nintedanib seems more effective than Avastin and has the potential to be a novel therapy for preventing corneal NV.     

Outcomes of conbercept therapy for choroidal neovascularization secondary to pathological myopia

AIM: To evaluate the one-year outcome of intravitreal conbercept injections for the treatment of choroidal neovascularization secondary to pathological myopia (pm-CNV) by optical coherence tomography angiography (OCTA). METHODS: The medical records of 26 consecutive eyes of 23 patients who received intravitreal injections of conbercept for pm-CNV with a follow-up of one year were retrospectively reviewed. All the patients were diagnosed by fundus fluorescein angiography (FFA) and OCTA at the first visit. All approaches were performed as “1+PRN” treatment. Outcomes included best-corrected visual acuity (BCVA), central foveal thickness (CFT) and the mean CNV area by OCTA. RESULTS: Mean Logarithm BCVA improved from (0.66±0.51) at baseline to (0.39±0.38) at one year (t=3.528, P=0.004). The CFT before treatment and after one year after were 275.08±48.74) μm and (205.15±43.74) μm respectively (t=4.630, P=0.001). The mean pm-CNV areas before treatment and after one year treatment were (0.48±0.24) mm2 and (0.15±0.11) mm2 respectively, with a significant difference among them (t=5.329, P=0.000). Twenty-one eyes had no needs after the first treatment. Four eyes received 2 injections and only one eye received 3 injections. No severe adverse events were noted relevant to the therapy. CONCLUSION: Intravitreal conbercept can improve the vision and relieve CFT and CNV area for the treatment of pm-CNV with “1+PRN” by OCTA for one year, however, long-term follow-up still need to be performed.     

动态增强MRI评价脊柱肿瘤血供与DSA的相关性

目的 确定动态增强磁共振成像(DCE-MRI)在评价脊柱肿瘤血供与DSA染色的相关性.方法 40例诊断为脊柱肿瘤的患者在行栓塞术前作MR检查.根据血管造影表现,肿瘤分为富血供组、中等血供组和乏血供组.通过对肿瘤强化区域的感兴趣区(ROI)分析,应用常规MR的强化程度和DCE-MRI参数评价肿瘤血供.结果 40例肿瘤分为乏血供组(16例)、中等血供组(12例)和富血供组(12例).MRI强化程度在乏血供组和富血供组间没有统计学差异(P>0.05).而DCE-MRI在两组间显示差异有统计学意义(P＜0.01).而且相对于MRI强化程度,DCE-MRI参数与DSA的关系更加密切.RSlopemax临界值为1.325时预测乏血供肿瘤的特异度和灵敏度最高,分别为100％和87.5％,而临界值为1.85时用于预测富血供肿瘤的特异度和灵敏度最高,分别为100％和96.4％.结论 与常规MRI相比,DCE-MRI可以更准确地评价脊柱肿瘤血供,而且显示与DSA更好的相关性.     

Choroidal and macular thickness changes in type 1 diabetes mellitus patients without diabetic retinopathy

Objectives: To explore choroidal thickness (ChT) and retinal thickness (RT) changes in patients with type 1 diabetes mellitus (DM).

Methods: Sixty patients with Type 1 DM and 60 age- and sex-matched healthy controls were included in this prospective case–control clinical study. All patients underwent a complete ophthalmological examination. ChT of each participant was measured at the fovea and horizontal nasal and temporal quadrants at 500-µm intervals to 1500 µm from the foveola using spectral-domain optical coherence tomography (SD-OCT). Age, gender, disease duration, serum glycosylated hemoglobin (HbA1c), fasting glucose level, axial length (AL) and refractive error were noted and analyzed.

Results: Mean disease duration, mean HbA1c and mean fasting blood glucose in diabetic patients were 6.1±2.8 years, (8.9±0.9)% and 287.5±69.1 mg/dl, respectively. Age, gender, AL, spherical equivalent differences between the patients and subjects were insignificant (p>0.05). Subfoveal ChT, nasal quadrant ChT measurements, temporal 1500 µm and mean nasal ChT were significantly lower in diabetic patients (p<0.05 for all). Temporal 500 µm and 1000 µm ChT measurements, mean temporal ChT, average ChT, central macular thickness and average macular thickness did not differ significantly between the groups (p>0.05 for all).

Conclusion: This study showed that there is choroidal thinning in young Type 1 diabetic patients with early period of disease duration without diabetic retinopathy nor any other systemic diseases. Choroidal changes in type 1 DM seem to begin at nasal and distal temporal retina. These results need to be verified by larger and longitudinal studies.     

Contribution of VCAF-positive cells to neovascularization and calcification in atherosclerotic plaque development

Calcification of the vessel wall is a regulated process with many similarities to osteogenesis. Progenitor cells may play a role in this process. Previously, we identified a novel gene, Vascular Calcification Associated Factor (VCAF), which was shown to be important in pericyte osteogenic differentiation. The aim of this study was to determine the localization and expression pattern of VCAF in human cells and tissues. Immunohistochemical analysis of seven atherosclerotic arteries confirmed VCAF protein expression within calcified lesions. In addition, individual VCAF-positive cells were detected within the intima and adventitia in areas where sporadic 3G5-positive pericytes were localized. Furthermore, VCAF-positive cells were identified in newly formed microvessels in association with CD34-positive/CD146-positive/c-kit-positive cells as well as in intact CD31-positive endothelium in internal mammary arteries. Western blot analysis confirmed the presence of VCAF (18 kD) in protein lysates extracted from human smooth muscle cells, endothelial cells, macrophages, and osteoblasts. In fracture callus samples from three patients, VCAF was detected in osteoblasts and microvessels. This study demonstrates the presence of VCAF in neovessels and raises the possibility that VCAF could be a new marker for vascular progenitor cells involved in a number of differentiation pathways. These data may have implications for the prevention or treatment of vascular disease.     

Effects of sunitinib and bevacizumab on VEGF and miRNA levels on corneal neovascularization

Aim: To evaluate the effects of sunitinib (0.5?mg/ml) and bevacizumab (5?mg/ml) on VEGF-A, VEGFR-2 and microRNA (miRNA) levels on corneal neovascularization (CNV).

Methods: In this study, CNV was induced by silver nitrate application to the cornea, and 40 Albino male rats were equally divided into four subgroups:

Group 1 (sunitinib): After silver nitrate application to the cornea, 0.5?mg/ml sunitinib eyedrop was administered twice daily for two weeks (n?=?10).

Group 2 (bevacizumab): After silver nitrate application to the cornea, 5?mg/ml bevacizumab eyedrop was administered twice daily for two weeks (n?=?10).

Group 3 (control): After silver nitrate application to the cornea, normal saline eyedrop was administered twice daily for two weeks (n?=?10).

Group 4 (vehicle): After silver nitrate application to the cornea, 1% DMSO eyedrop was administered twice daily for two weeks (n?=?10).

After two weeks from the silver nitrate application, corneas were evaluated by hand-held biomicroscope for their vascularization status. Then, corneas were excised and the expression levels of VEGFR-2, VEGF-A and the common miRNA markers for neovascularization (miR-15?b, miR-16, miR-23a, miR-126, miR-188, miR-210, miR-221, miR-222, miR-410 and miR-423) were evaluated by real-time PCR.

Results: It was seen that the CNV was decreased in sunitinib- and bevacizumab-administered groups compared to the control and DMSO groups. Also, in comparison with the control group; VEGF-A expression was downregulated by nearly 0.75 times in sunitinib group and nearly 0.52 times in bevacizumab group. VEGFR-2 expression was downregulated by 0.89 times in sunitinib group and 0.68 times in bevacizumab group, compared to the control group. miR-15?b, miR-16 and miR-126 levels were statistically lower in sunitinib and bevacizumab groups, but miR-188 and miR-410 levels were two-fold higher compared to the control group. The miR-210 level was found higher only in sunitinib group compared to the control group. There were no statistically significant changes in miR-23a, miR-221, miR-222 and miR-423 levels among the groups.

Conclusion: Topical application of bevacizumab (5?mg/ml) and sunitinib (0.5?mg/ml) decreases the levels of VEGFR-2 and VEGF-A in CNV. Further studies are needed for detailed analysis of genes which are targeted by up- or downregulated miRNAs in this study.     

Immunosubunit β5i Knockout Suppresses Neovascularization and Restores Autophagy in Retinal Neovascularization by Targeting ATG5 for Degradation

PurposeTo investigate the functional role of immunoproteasome subunit β5i in pathologic retinal neovascularization (RNV) and its ability to link the immunoproteasome and autophagy.MethodsOxygen-induced retinopathy (OIR) was induced in wild-type (WT) and β5i knockout (KO) mouse pups on a C57BL/6J background. Proteasome catalytic subunit expression and proteasome activity were evaluated by quantitative real-time PCR (qPCR) and proteasome activity. Retinal vascular anatomy and neovascularization were characterized and quantified by retinal vascular flat-mount staining, fluorescence angiography, platelet endothelial cell adhesion molecule (PECAM) immunostaining, and hematoxylin and eosin staining. Correlation factors, including VEGF and ICAM-1, were detected by qPCR. Autophagy was examined by transmission electron microscopy (TEM). Autophagy biomarkers, including LC3, P62, ATG5, and ATG7, were measured by immunostaining and immunoblotting. The protein interaction between β5i and ATG5 was detected by immunoprecipitation.ResultsWe observed that β5i had the greatest effect in WT OIR mice. Fundus fluorescence angiography, retinal flat-mount staining, and PECAM staining revealed that pathologic RNV decreased in β5i KO OIR mice compared with WT OIR mice. Concurrently, TEM, immunostaining, and immunoblotting showed that autophagy was induced in β5i KO OIR mice compared to WT OIR mice through increases in autophagosome and LC3 expression and a decrease in P62. Mechanistically, β5i interacted with ATG5 and promoted its degradation, leading to autophagy inhibition and pathogenic RNV.ConclusionsThis study identifies a functional role for β5i in RNV regulation. β5i deletion ameliorates RNV and restores autophagy by stabilizing ATG5. These results demonstrate the potential of β5i to serve as a bridge linking the immunoproteasome and autophagy.     

Membrana neovascular yuxtapapilar asociada a drusas del nervio óptico

Clinical caseForteen year old patient presenting progressive decrease in visual acuity of the left eye after 3 months of evolution. On examination he presents bilateral drusen of papilla, associated with juxtapapillary neovascular membrane, which seriously compromises the vision and visual field of the left eye.ResultTreatment with 3 consecutive injections of intravitreal ranibizumab resulted in the inactivation of the neovascular membrane with reabsorption of subretinal fluid and improvement of the best corrected visual acuity of the left eye. After 9 months of follow-up, it was 20/20 and stable.ConclusionAlthough optic nerve head drusen are considered benign, neovascular membranes can be a complication. Anti-VEGFs are an effective alternative for treatment.