Mechanistically distinct mouse models for CRX-associated retinopathy.
Mechanistically distinct mouse models for CRX-associated retinopathy.
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DOI：
10.1371/journal.pgen.1004111
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发表时间：
2014-02
期刊：
影响因子：
4.5
通讯作者：
Chen S
中科院分区：
文献类型：
--
作者：
Tran NM;Zhang A;Zhang X;Huecker JB;Hennig AK;Chen S
锥杆同源盒蛋白（CRX）是一种“配对样”同源结构域转录因子，对调节杆状和锥状光感受器转录至关重要。人类CRX突变与主要视网膜病变色素性视网膜炎（RP）、锥体杆营养不良（CoRD）和Leber先天性黑朦（LCA）相关，严重程度不一。杂合子Crx敲除（KO）小鼠（“+/−”）具有正常的成年视力，并且不能模拟主要的人类疾病。为了研究不同突变的CRX蛋白如何产生不同的疾病病理，我们建立了两种CRX敲入（K-IN）小鼠模型：CrxE168d2（“E168d2”）和CrxR90W（“R90W”）。E168d2小鼠在CRX激活域Glu168del2中携带移码突变，这与人类严重的显性CoRD或LCA有关。R90W小鼠携带CRX同源结构域Arg90Trp的替代突变，该突变与显性轻度迟发性CoRD和隐性LCA相关。正如在人类患者中所见，杂合子E168d2（“E168d2/+”）而非R90W（“R90W/+”）小鼠的视网膜功能严重受损，而纯合子任何一种突变的小鼠都失明并经历快速的光受体变性。与R90W/+或+/−小鼠相比，E168d2/+小鼠也表现出杆/锥形态异常，CRX靶基因表达受损更严重，并发生进行性光感受器变性。令人惊讶的是，E168d2/+小鼠比野生型CRX表达更多的突变型CRX蛋白。E168d2neo/+是E168d2突变等位基因表达减少的一个亚系，其视网膜表型要温和得多，这表明Crx表达水平对疾病严重程度的影响。CRX[E168d2]和CRX[R90W]蛋白在体外均不能激活转录，但CRX[E168d2]对野生型（WT） CRX的功能干扰更强，支持反同形机制。E168d2和R90W是机制上不同的crx相关疾病小鼠模型，这将有助于阐明不同形式crx相关疾病的分子机制和测试新的治疗方法。转录因子锥杆同源盒（CRX）在调节视杆和视锥光感受器的基因表达中起核心作用，视杆和视锥光感受器是视网膜的主要光感应细胞。人类CRX基因突变与视网膜变性疾病色素性视网膜炎（RP）、锥体杆营养不良（CoRD）和Leber先天性黑朦（LCA）有关。这些疾病导致进行性和永久性视力丧失，发病年龄和严重程度差别很大，目前无法治愈。为了了解CRX的突变是如何引起不同形式的视网膜疾病的，我们对小鼠进行了基因工程改造，使其携带CRX基因中引起人类疾病的突变。这些小鼠品系准确地概括了不同形式的CRX相关疾病，表明不同类型的CRX突变是人类表型变异的原因。我们已经确定了这些小鼠的病理特征，并确定了疾病的关键机制。此外，我们发现，在一个突变模型中，改变突变蛋白的水平对疾病病理有显著影响，这表明针对突变CRX的靶向治疗可能是一种有效的治疗策略。这些小鼠模型将允许测试由CRX突变引起的视网膜疾病的新治疗策略。
Cone-rod homeobox (CRX) protein is a “paired-like” homeodomain transcription factor that is essential for regulating rod and cone photoreceptor transcription. Mutations in human CRX are associated with the dominant retinopathies Retinitis Pigmentosa (RP), Cone-Rod Dystrophy (CoRD) and Leber Congenital Amaurosis (LCA), with variable severity. Heterozygous Crx Knock-Out (KO) mice (“+/−”) have normal vision as adults and fail to model the dominant human disease. To investigate how different mutant CRX proteins produce distinct disease pathologies, we generated two Crx Knock-IN (K-IN) mouse models: CrxE168d2 (“E168d2”) and CrxR90W (“R90W”). E168d2 mice carry a frameshift mutation in the CRX activation domain, Glu168del2, which is associated with severe dominant CoRD or LCA in humans. R90W mice carry a substitution mutation in the CRX homeodomain, Arg90Trp, which is associated with dominant mild late-onset CoRD and recessive LCA. As seen in human patients, heterozygous E168d2 (“E168d2/+”) but not R90W (“R90W/+”) mice show severely impaired retinal function, while mice homozygous for either mutation are blind and undergo rapid photoreceptor degeneration. E168d2/+ mice also display abnormal rod/cone morphology, greater impairment of CRX target gene expression than R90W/+ or +/− mice, and undergo progressive photoreceptor degeneration. Surprisingly, E168d2/+ mice express more mutant CRX protein than wild-type CRX. E168d2neo/+, a subline of E168d2 with reduced mutant allele expression, displays a much milder retinal phenotype, demonstrating the impact of Crx expression level on disease severity. Both CRX[E168d2] and CRX[R90W] proteins fail to activate transcription in vitro, but CRX[E168d2] interferes more strongly with the function of wild type (WT) CRX, supporting an antimorphic mechanism. E168d2 and R90W are mechanistically distinct mouse models for CRX-associated disease that will allow the elucidation of molecular mechanisms and testing of novel therapeutic approaches for different forms of CRX-associated disease. The transcription factor Cone-Rod Homeobox (CRX) plays a central role in regulating gene expression of rod and cone photoreceptors, the primary light sensing cells of the retina. Mutations in the human CRX gene have been associated with the retinal degeneration diseases Retinitis Pigmentosa (RP), Cone-Rod Dystrophy (CoRD) and Leber Congential Amaurosis (LCA). These diseases cause progressive and permanent loss of vision, vary widely in age of onset and severity, and are currently untreatable. To understand how mutations in CRX cause distinct forms of retinal disease, we have genetically engineered mice to carry human disease-causing mutations in their Crx gene. These mouse lines accurately recapitulate distinct forms of CRX-associated disease, demonstrating that different classes of CRX mutations are responsible for phenotype variability in humans. We have characterized the pathology of these mice and identified critical mechanisms of disease. In addition, we have discovered that modifying the level of mutant protein had a dramatic effect on disease pathology in one mutant model, suggesting that targeted therapy against the mutant CRX could be an effective treatment strategy. These mouse models will allow for the testing of novel therapeutic strategies for retinal diseases caused by CRX mutations.
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影响因子：
16.2
作者：
Chen, SM;Wang, QL;Zack, DJ
通讯作者：
Zack, DJ
影响因子：
3.5
作者：
Chen, SM;Peng, GH;La Spada, AR
通讯作者：
La Spada, AR
锥杆营养不良中的 CRX 变异和突变概述
DOI：
10.1016/j.bbrc.2012.08.110
发表时间：
2012-10-05
影响因子：
3.1
作者：
Huang, Li;Xiao, Xueshan;Zhang, Qingjiong
通讯作者：
Zhang, Qingjiong
影响因子：
2.6
作者：
Hayashi, Shigemi;Lewis, Paula;McMahon, Andrew P.
通讯作者：
McMahon, Andrew P.
影响因子：
17.8
作者：
Berger, Wolfgang;Kloeckener-Gruissem, Barbara;Neidhardt, John
通讯作者：
Neidhardt, John