Regeneration of the zebrafish retinal pigment epithelium after widespread genetic ablation
Regeneration of the zebrafish retinal pigment epithelium after widespread genetic ablation
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DOI：
10.1371/journal.pgen.1007939
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发表时间：
2019-01-01
期刊：
影响因子：
4.5
通讯作者：
Gross, Jeffrey M.
中科院分区：
文献类型：
--
作者：
Hanovice, Nicholas J.;Leach, Lyndsay L.;Gross, Jeffrey M.
视网膜色素上皮（RPE）是眼内一种特殊的单层色素细胞，对维持视觉系统功能至关重要。影响RPE的疾病对视力有可怕的后果，其中最普遍的是萎缩性（干性）年龄相关性黄斑变性（AMD），这被认为是由RPE功能障碍和变性引起的。治疗萎缩性AMD等RPE退行性疾病的一个有趣的可能性是刺激内源性RPE再生；然而，对于RPE在体内成功再生的机制知之甚少。在这里，我们开发了一种斑马鱼转基因模型（rpe65a:nfsB-eGFP），可以切除大片成熟的RPE。RPE消融导致RPE快速变性，以及布鲁氏膜和底层光感受器的变性。使用该模型，我们首次证明斑马鱼在RPE消融后能够再生功能性RPE单层。再生的RPE细胞首先出现在RPE的周围，然后以周围到中心的方式进行再生。RPE消融在剩余的RPE中引起强烈的增殖反应。随后，增殖细胞进入损伤部位并分化为RPE。BrdU掺入实验表明再生的RPE可能来源于剩余的外周RPE细胞。使用IWR-1（一种Wnt信号拮抗剂）进行药物干扰可显著降低RPE中的细胞增殖，并损害RPE的整体恢复。这些数据表明，斑马鱼RPE具有强大的再生能力，并强调了内源性RPE在体内再生的潜在机制。导致视网膜色素上皮（RPE）变性的疾病是全世界失明的主要原因之一，目前还没有一种治疗方法可以替代RPE或恢复视力。一种有趣的可能性是专注于刺激内源性RPE再生的治疗方法的发展。要做到这一点，我们必须首先更深入地了解RPE再生的机制。在这里，我们开发了一种转基因斑马鱼系统，通过该系统，我们切除了大片成熟的RPE，并证明斑马鱼在大范围损伤后再生RPE。损伤附近的RPE增殖并再生RPE，表明它们是再生组织的来源。最后，我们证明Wnt信号可能参与RPE再生。这些发现建立了一个多功能的体内模型，通过该模型可以进一步表征RPE再生的分子和细胞基础。
The retinal pigment epithelium (RPE) is a specialized monolayer of pigmented cells within the eye that is critical for maintaining visual system function. Diseases affecting the RPE have dire consequences for vision, and the most prevalent of these is atrophic (dry) age-related macular degeneration (AMD), which is thought to result from RPE dysfunction and degeneration. An intriguing possibility for treating RPE degenerative diseases like atrophic AMD is the stimulation of endogenous RPE regeneration; however, very little is known about the mechanisms driving successful RPE regeneration in vivo. Here, we developed a zebrafish transgenic model (rpe65a:nfsB-eGFP) that enabled ablation of large swathes of mature RPE. RPE ablation resulted in rapid RPE degeneration, as well as degeneration of Bruch's membrane and underlying photoreceptors. Using this model, we demonstrate for the first time that zebrafish are capable of regenerating a functional RPE monolayer after RPE ablation. Regenerated RPE cells first appear at the periphery of the RPE, and regeneration proceeds in a peripheral-to-central fashion. RPE ablation elicits a robust proliferative response in the remaining RPE. Subsequently, proliferative cells move into the injury site and differentiate into RPE. BrdU incorporation assays demonstrate that the regenerated RPE is likely derived from remaining peripheral RPE cells. Pharmacological disruption using IWR-1, a Wnt signaling antagonist, significantly reduces cell proliferation in the RPE and impairs overall RPE recovery. These data demonstrate that the zebrafish RPE possesses a robust capacity for regeneration and highlight a potential mechanism through which endogenous RPE regenerate in vivo.Author summary Diseases resulting in retinal pigment epithelium (RPE) degeneration are among the leading causes of blindness worldwide, and no therapy exists that can replace RPE or restore lost vision. One intriguing possibility is the development of therapies focused on stimulating endogenous RPE regeneration. For this to be possible, we must first gain a deeper understanding of the mechanisms underlying RPE regeneration. Here, we develop a transgenic zebrafish system through which we ablate large swathes of mature RPE and demonstrate that zebrafish regenerate RPE after widespread injury. Injury-adjacent RPE proliferate and regenerate RPE, suggesting that they are the source of regenerated tissue. Finally, we demonstrate that Wnt signaling may be involved in RPE regeneration. These findings establish a versatile in vivo model through which the molecular and cellular underpinnings of RPE regeneration can be further characterized.