权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Investigation of the mechanisms of diabetic vitreoretinopathy and its pharmaceutical regulation

糖尿病玻璃体视网膜病变的发病机制及其药物调控研究

基本信息

批准号：
17591839
负责人：
HATA Yasuaki
金额：
$ 2.24万
依托单位：
KYUSHU UNIVERCITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17591839/
关键词：
Diabetic retinopathy macular edema VEGF TGF-beta CTGF Hyalocytes Rho-kinase Neovascularization 糖尿病網膜硝子体症 PDGF

项目摘要

Diabetic retinopathy including diabetic macular edema is considered to be caused not only by the pathological change of the retina but also by that of the vitreous. Therefore, the pathological condition should be considered as diabetic vitreoretinopathy rather than simply as diabetic retinopathy. However, precise mechanisms are not fully understood to date.We are focusing on the functional change of hyalocytes (a macrophage lineage in the vitreous cavity) and retinal vascular endothelial cells under the pathological conditions. In addition, we suppose that rho-kinase might be a possible therapeutic target for the treatment of diabetic vitreoretinopathy. In the present study, we used Fasudil which is a rho-kinase inhibitor already in clinical use fro the treatment of erebrovascular spasm.We previously reported that Fasudil could be able to inhibit the cicatrical contraction of proliferative membrane using cultured hyalocytes. The critical association of connective tissue growth factor ( … More CTGF), which is thought to be one of the downstream mediators of transforming growth factor-beta (TGF-beta), with vitreoretinal diseases remains to be clarified. In the present study, we first demonstrated the correlation between the concentrations of TGF-beta2 and CTGF in the vitreous, and CTGF gene regulation in cultured hyalocytes. Concentrations of TGF-beta2 and CTGF in the vitreous from patients with proliferative vitreoretinal diseases were significantly higher than those with non-proliferative diseases and there was a positive correlation between their concentrations (r=0.320,p<0.01). Cultured hyalocytes expressed CTGF mRNA, which was enhanced in the presence of TGF-beta2,associated with nuclear accumulation of Smad4. The TGF-beta2-dependent Smad4 translocation and CTGF gene expression were mediated through Rho kinase and at least partially via p38 MAPK. Fasudil inhibited both of Smad4 translocation and CTGF gene expression. In conclusion, combined effects of TGF-beta2 and CTGF appear to be involved in the pathogenesis of proliferative vitreoretnal diseases. Hyalocytes may be a possible source of CTGF and thus might play a role in vitreoretinal interface diseases. Furthermore, Rho kinase inhibitors might have therapeutic potential to control fibrotic disorders in the eye.Vascular endothelial growth factor (VEGF) plays pivotal roles in the pathogenesis of angiogenesis. In this study, we addressed the therapeutic potential of fasudil for VEGF-elicited angiogenesis and also its intracellular signaling. VEGF-elicited angiogenesis in corneal micro-pocket assay was potently attenuated by co-embedding with fasudil (p<0.01). VEGF caused MLC phosphorylation of BRECs, which was almost completely abrogated by fasudil. VEGF-dependent phosphorylation of ERK1/2 and Akt were also significantly abrogated by the treatment with fasudil without affecting VEGFR2 (KDR) phosphorylation. Moreover, both VEGF-induced [3H]-thymidine uptake and migration of BRECs were significantly inhibited in the presence of fasudil. These findings indicate that fasudil might have therapeutic potential for ocular angiogenic diseases. The anti-angiogenic effect of fasudil appears to be mediated through the blockade not only of Rho-kinase signaling but also of ERK and Akt signalings. Less

糖尿病视网膜病变包括糖尿病黄斑水肿，被认为不仅是由视网膜的病变引起的，也是由玻璃体的病变引起的。因此，其病理状态应考虑为糖尿病玻璃体视网膜病变，而不是单纯的糖尿病视网膜病变。然而，到目前为止，确切的机制还不完全清楚。我们关注的是玻璃体腔内的一种巨噬细胞系--透明细胞和视网膜血管内皮细胞在病理条件下的功能变化。此外，我们认为Rho-Kinase可能是治疗糖尿病玻璃体视网膜病变的一个可能的靶点。在本研究中，我们使用已在临床上使用的Rho-Kinase抑制剂法舒地尔治疗脑血管痉挛。我们先前报道，法舒地尔可以通过培养的透明细胞抑制增殖膜的瘢痕收缩。结缔组织生长因子(…)的临界关联性更多的CTGF)，被认为是转化生长因子-β(TGF-β)的下游介质之一，与玻璃体视网膜疾病的关系尚不清楚。在本研究中，我们首次证实了玻璃体中转化生长因子-β2和结缔组织生长因子的浓度与培养的透明细胞中结缔组织生长因子基因调控的相关性。增殖性玻璃体视网膜疾病患者玻璃体中转化生长因子-β2和结缔组织生长因子的浓度显著高于非增殖性玻璃体视网膜疾病患者，且两者浓度呈正相关(r=0.320，p&lt；0.01)。培养的肺透明细胞表达CTGF mRNA，在转化生长因子-β2存在的情况下其表达增强，并伴随着Smad4的核积聚。依赖于转化生长因子-β2的Smad4易位和CTGF基因表达是通过Rho激酶和至少部分通过p38MAPK介导的。法舒地尔同时抑制Smad4易位和CTGF基因表达。综上所述，转化生长因子-β2和结缔组织生长因子的联合作用可能参与了增殖性玻璃体视网膜疾病的发病机制。透明细胞可能是CTGF的一个可能来源，因此可能在玻璃体-视网膜交界处疾病中发挥作用。此外，Rho激酶抑制剂可能具有控制眼部纤维化疾病的治疗潜力。血管内皮生长因子(VEGF)在血管生成的发病机制中发挥着关键作用。在这项研究中，我们探讨了法舒地尔对血管内皮生长因子诱导的血管生成及其细胞内信号转导的治疗潜力。与法舒地尔共包埋后，角膜微囊实验中血管生成明显减弱(p&lt；0.01)。血管内皮细胞生长因子引起BRECs的MLC磷酸化，法舒地尔几乎完全阻断这一作用。法舒地尔可显著抑制血管内皮生长因子依赖性的ERK1/2和Akt的磷酸化，而不影响VEGFR2(KDR)的磷酸化。此外，法舒地尔显著抑制了血管内皮生长因子诱导的BRECs对[~3H]-TdR的摄取和迁移。这些发现表明，法舒地尔可能对眼部血管源性疾病具有治疗潜力。法舒地尔的抗血管生成作用似乎不仅通过阻断Rho-Kinase信号途径实现，还通过阻断ERK和Akt信号途径实现。较少