Integrin activation or alpha9 expression allows retinal pigmented epithelial cell adhesion on Bruch's membrane in wet age-related macular degeneration
Integrin activation or alpha9 expression allows retinal pigmented epithelial cell adhesion on Bruch's membrane in wet age-related macular degeneration
复制标题
DOI：
10.1093/brain/awp319
复制
发表时间：
2010-02-01
期刊：
影响因子：
14.5
通讯作者：
Fawcett, James W.
中科院分区：
文献类型：
--
作者：
Afshari, Fardad T.;Kwok, Jessica C.;Fawcett, James W.
视网膜色素上皮细胞功能障碍是年龄相关性黄斑变性的一个致病特征，新的视网膜色素上皮细胞的移植是一种有吸引力的策略，以防止进一步的进展和视力丧失。然而，移植显示出有限的功效，主要是因为移植的细胞不能粘附和迁移到病理性布鲁赫膜上。与布鲁赫膜的粘附是整合素介导的。布鲁赫膜的老化导致整联蛋白配体的下降，此外，湿性年龄相关性黄斑变性导致抗粘附分子如腱生蛋白-C的上调。因此，我们研究了是否在视网膜色素上皮细胞的整合素功能的操作可以恢复他们的粘附和迁移湿性年龄相关性黄斑变性受损的布鲁赫膜。使用自发永生化的人视网膜色素上皮细胞（成人视网膜色素上皮细胞-19），我们表明，在布鲁赫膜组件的粘附和迁移是整合素依赖性的，并通过整合素激活剂锰和TS 2/16增强。这使得细胞能够在低浓度的配体上粘附和迁移，就像在老化的布鲁赫膜中发现的那样。我们接下来开发了一种从Bruch膜上剥离细胞的方法，以便可以在其表面上进行粘附和迁移测定。整合素活化对增强视网膜色素上皮细胞在正常人和大鼠布鲁赫膜上的粘附和迁移具有中等影响。然而，在从受人类湿性年龄相关性黄斑变性影响的眼睛制备的Bruch膜上，粘附性较低并且整合素活化具有大得多的作用。用于防止视网膜色素上皮与年龄相关性黄斑变性影响的布鲁赫膜相互作用的候选分子是腱生蛋白-C，我们证实其以高水平存在于湿性年龄相关性黄斑变性膜中。我们表明，腱生蛋白-C是抗粘附的视网膜色素上皮细胞，但整合素激活后，他们可以坚持和迁移使用α V β 3整合素。另外，我们发现用α 9整联蛋白（一种腱生蛋白-C结合整联蛋白）转导视网膜色素上皮细胞导致α 9 β 1介导的腱生蛋白-C粘附和迁移大幅增加。α 9整联蛋白的表达和整联蛋白的激活都大大增强了视网膜色素上皮细胞粘附于富含腱生蛋白的受年龄相关性黄斑变性影响的布鲁赫膜的能力。我们的研究结果表明，通过整合素激活策略，或表达新的整合素，如α 9，视网膜色素上皮细胞整合素的操作，可以有效地提高视网膜色素上皮细胞移植在湿性年龄相关性黄斑变性影响的眼睛的疗效。
Retinal pigment epithelial cell malfunction is a causative feature of age-related macular degeneration, and transplantation of new retinal pigment epithelial cells is an attractive strategy to prevent further progression and visual loss. However, transplants have shown limited efficacy, mainly because transplanted cells fail to adhere and migrate onto pathological Bruch's membrane. Adhesion to Bruch's membrane is integrin-mediated. Ageing of Bruch's membrane leads to a decline in integrin ligands and, added to this, wet age-related macular degeneration leads to upregulation of anti-adhesive molecules such as tenascin-C. We have therefore investigated whether manipulation of integrin function in retinal pigment epithelial cells can restore their adhesion and migration on wet age-related macular degeneration-damaged Bruch's membrane. Using spontaneously immortalized human retinal pigment epithelial cells (adult retinal pigment epithelium-19), we show that adhesion and migration on the Bruch's membrane components is integrin-dependent and enhanced by integrin-activating agents manganese and TS2/16. These allowed cells to adhere and migrate on low concentrations of ligand, as would be found in aged Bruch's membrane. We next developed a method for stripping cells from Bruch's membrane so that adhesion and migration assays can be performed on its surface. Integrin activation had a moderate effect on enhancing retinal pigmented epithelial cell adhesion and migration on normal human and rat Bruch's membrane. However, on Bruch's membrane prepared from human wet age-related macular degeneration-affected eyes, adhesion was lower and integrin activation had a much greater effect. A candidate molecule for preventing retinal pigmented epithelial interaction with age-related macular degeneration-affected Bruch's membrane is tenascin-C which we confirm is present at high levels in wet age-related macular degeneration membrane. We show that tenascin-C is anti-adhesive for retinal pigmented epithelial cells, but after integrin activation, they can adhere and migrate on it using alphaVbeta3 integrin. Alternatively, we find that transduction of retinal pigmented epithelial cells with alpha9 integrin, a tenascin-C-binding integrin, led to a large increase in alpha9beta1-mediated adhesion and migration on tenascin-C. Both expression of alpha9 integrin and integrin activation greatly enhanced the ability of retinal pigment epithelial cells to adhere to tenascin-rich wet age-related macular degeneration-affected Bruch's membranes. Our results suggest that manipulation of retinal pigment epithelial cell integrins through integrin activating strategies, or expression of new integrins such as alpha9, could be effective in improving the efficacy of retinal pigment epithelial cell transplantation in wet age-related macular degeneration-affected eyes.