A Zebrafish Model of Axenfeld-Rieger Syndrome Reveals That pitx2 Regulation by Retinoic Acid Is Essential for Ocular and Craniofacial Development
A Zebrafish Model of Axenfeld-Rieger Syndrome Reveals That pitx2 Regulation by Retinoic Acid Is Essential for Ocular and Craniofacial Development
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DOI：
10.1167/iovs.11-8494
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发表时间：
2012-01-01
影响因子：
4.4
通讯作者：
Kahana, Alon
中科院分区：
文献类型：
--
作者：
Bohnsack, Brenda L.;Kasprick, Daniel S.;Kahana, Alon
目的。同源框转录因子PITX2是哺乳动物眼睛发育的已知调节因子，人类PITX2突变与阿森菲尔德-里格综合征(ARS)有关。然而，对ARS患者的治疗仍然主要是支持性和姑息性的。方法：作者利用分子遗传学、药理学和胚胎学技术在斑马鱼模型中研究了ARS的生物学，该模型使用转基因标记头部的神经脊和肌肉细胞。结果：作者在体内证明了Pitx2是维甲酸(RA)在颅面发育中的关键下游靶点，这一途径是协调神经脊、中胚层和眼睛发育所必需的。使用吗啉寡核苷酸敲除Pitx2a基因会破坏颌骨和咽弓的形成，并重现ARS的眼部特征，包括角膜和虹膜基质发育不良。这些表型可以用人PITX2AmRNA挽救，证明了Pitx2a功能被敲除的特异性和进化保守性。ARS显性阴性的人PITX2AK50E等位基因的表达也导致了ARS样表型。类似地，发育眼(遗传或药物)中RA合成的抑制扰乱了颅面和眼的发育，而人类PITX2AmRNA部分挽救了这些缺陷。结论：RA调节Pitx2对于协调神经脊、中胚层和发育眼之间的相互作用是必不可少的。在眼睛和颅面发育中，Pitx2功能的显著进化保守使斑马鱼成为潜在的ARS的强大模型，易于进行体内实验和开发潜在的治疗方法。(投资眼科VS科学。2012年；53：7-22)doi：10.1167/iovs.11-8494
PURPOSE. The homeobox transcription factor PITX2 is a known regulator of mammalian ocular development, and human PITX2 mutations are associated with Axenfeld-Rieger syndrome (ARS). However, the treatment of patients with ARS remains mostly supportive and palliative.METHODS. The authors used molecular genetic, pharmacologic, and embryologic techniques to study the biology of ARS in a zebrafish model that uses transgenes to mark neural crest and muscle cells in the head.RESULTS. The authors demonstrated in vivo that pitx2 is a key downstream target of retinoic acid (RA) in craniofacial development, and this pathway is required for coordinating neural crest, mesoderm, and ocular development. pitx2a knockdown using morpholino oligonucleotides disrupts jaw and pharyngeal arch formation and recapitulates ocular characteristics of ARS, including corneal and iris stroma maldevelopment. These phenotypes could be rescued with human PITX2A mRNA, demonstrating the specificity of the knockdown and evolutionary conservation of pitx2a function. Expression of the ARS dominant negative human PITX2A K50E allele also caused ARS-like phenotypes. Similarly, inhibition of RA synthesis in the developing eye (genetic or pharmacologic) disrupted craniofacial and ocular development, and human PITX2A mRNA partially rescued these defects.CONCLUSIONS. RA regulation of pitx2 is essential for coordinating interactions among neural crest, mesoderm, and developing eye. The marked evolutionary conservation of Pitx2 function in eye and craniofacial development makes zebrafish a potentially powerful model of ARS, amenable to in vivo experimentation and development of potential therapies. (Invest Ophthalmol Vis Sci. 2012;53:7-22) DOI:10.1167/iovs.11-8494