Inhibition of corneal neovascularization by blocking the angiotensin II type 1 receptor.
Inhibition of corneal neovascularization by blocking the angiotensin II type 1 receptor.
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DOI：
10.1167/iovs.07-0964
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发表时间：
2008-10
影响因子：
4.4
通讯作者：
T. Usui;Kenji Sugisaki;A. Iriyama;Seiichi Yokoo;S. Yamagami;N. Nagai;S. Ishida;S. Amano
中科院分区：
文献类型：
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作者：
T. Usui;Kenji Sugisaki;A. Iriyama;Seiichi Yokoo;S. Yamagami;N. Nagai;S. Ishida;S. Amano
目的探讨血管紧张素Ⅱ 1型受体（AT 1 R）信号通路在角膜新生血管形成中的作用。方法采用离角膜缘血管1 mm处注射尼龙10-0的方法诱导C57 BJ 6小鼠角膜新生血管。半定量逆转录聚合酶链反应（RT-PCR）检测血管紧张素原及其受体（AT 1 R）基因表达水平。Western blotting和免疫组化检测血管紧张素Ⅱ（Ang 2）和血管紧张素1受体（AT 1 R）的表达。为了研究Ang 2在角膜新生血管形成中的功能，在腹膜内注射AT 1 R拮抗剂（替米沙坦，10 mg/kg）后，研究了血管化角膜中浸润的巨噬细胞和新生血管化区域。此外，在对照组和替米沙坦给药组小鼠中检查了VEGF、MCP-1、IL-6、ICAM-1和TNF-α的角膜mRNA。结果新生血管化角膜组织中Ang 2和AT 1 R的表达较正常角膜组织明显增加。Ang 2和AT 1 R在新生血管化角膜的上皮细胞和基质细胞（血管内皮细胞、浸润白细胞和角膜细胞）中以蛋白水平表达，在正常角膜上皮细胞中检测到微弱表达。在给药后第7天，替米沙坦给药小鼠的浸润巨噬细胞减少。在角膜移植后第7天，替米沙坦给药小鼠角膜中的新生血管化面积比对照小鼠小70%。PPAR-gamma拮抗剂部分但显著逆转了替米沙坦对诱导角膜新生血管形成的抑制作用。替米沙坦处理的小鼠中VEGF、MCP-1、IL-6和ICAM-1的表达受到显著抑制。结论Ang 2在新生血管化角膜组织中表达丰富，在炎症相关角膜新生血管形成中起重要作用。AT 1 R可能是抑制角膜新生血管的治疗靶点。
PURPOSE To determine the role of angiotensin II type 1 receptor (AT1R) signaling in corneal neovascularization. METHODS Corneal neovascularization was induced by suturing 10-0 nylon 1 mm away from limbal vessels in C57 BJ6 mice. Angiotensinogen and its receptor (AT1R) gene expression levels were evaluated by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). The expression of angiotensin II (Ang2) and AT1R was confirmed by Western blotting and immunohistochemistry. To investigate the function of Ang2 in corneal neovascularization, infiltrating macrophages in vascularized corneas and the neovascularized area were investigated after intraperitoneal injection of an AT1R antagonist (telmisartan, 10 mg/kg). Further, corneal mRNA of VEGF, MCP-1, IL-6, ICAM-1, and TNF-alpha was examined in control and telmisartan-treated mice. RESULTS Ang2 and AT1R markedly increased in the neovascularized corneas compared with normal corneas. Ang2 and AT1R were expressed in epithelium and stromal cells (vascular endothelium, infiltrating leukocytes, and keratocytes) in neovascularized cornea at protein levels and were weakly detected in normal corneal epithelium. Infiltrating macrophages were reduced in telmisartan-treated mice on day 7 after suturing. Neovascularized area in the cornea of telmisartan-treated mice was 70% smaller than that of control mice on day 7 after suturing. A PPAR-gamma antagonist partially, but significantly, reversed the suppressive effect of telmisartan on induction of corneal neovascularization. The expression of VEGF, MCP-1, IL-6, and ICAM-1 was significantly inhibited in telmisartan-treated mice. CONCLUSIONS These findings indicate that Ang2, abundantly expressed in neovascularized corneas, has a significant role in inflammation-related driven corneal neovascularization. AT1R may be a therapeutic target for the suppression of corneal neovascularization.