Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA.
Ocular Gene Therapy Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Stem Cell Reports. 2022 Oct 11;17(10):2172-2186. doi: 10.1016/j.stemcr.2022.08.006. Epub 2022 Sep 8.
Mutations in the IQ calmodulin-binding motif containing B1 (IQCB1)/NPHP5 gene encoding the ciliary protein nephrocystin 5 cause early-onset blinding disease Leber congenital amaurosis (LCA), together with kidney dysfunction in Senior-Løken syndrome. For in vitro disease modeling, we obtained dermal fibroblasts from patients with NPHP5-LCA that were reprogrammed into induced pluripotent stem cells (iPSCs) and differentiated into retinal pigment epithelium (RPE) and retinal organoids. Patient fibroblasts and RPE demonstrated aberrantly elongated ciliary axonemes. Organoids revealed impaired development of outer segment structures, which are modified primary cilia, and mislocalization of visual pigments to photoreceptor cell soma. All patient-derived cells showed reduced levels of CEP290 protein, a critical cilia transition zone component interacting with NPHP5, providing a plausible mechanism for aberrant ciliary gating and cargo transport. Disease phenotype in NPHP5-LCA retinal organoids could be rescued by adeno-associated virus (AAV)-mediated IQCB1/NPHP5 gene augmentation therapy. Our studies thus establish a human disease model and a path for treatment of NPHP5-LCA.
IQ 钙调蛋白结合基序包含 B1（IQCB1）/NPHP5 基因突变导致早发性致盲疾病先天性黑蒙 Leber（LCA），同时伴有 Senior-Løken 综合征的肾功能障碍。为了进行体外疾病建模，我们从 NPHP5-LCA 患者中获得了皮肤成纤维细胞，这些细胞被重新编程为诱导多能干细胞（iPSCs），并分化为视网膜色素上皮（RPE）和视网膜类器官。患者的成纤维细胞和 RPE 表现出异常延长的纤毛轴丝。类器官显示出外节结构发育不良，这些结构是经过修饰的初级纤毛，以及视觉色素向光感受器细胞体的错位定位。所有患者来源的细胞都显示出 CEP290 蛋白水平降低，CEP290 蛋白是与 NPHP5 相互作用的关键纤毛过渡区成分，为异常纤毛门控和货物运输提供了一种合理的机制。腺相关病毒（AAV）介导的 IQCB1/NPHP5 基因增强治疗可挽救 NPHP5-LCA 视网膜类器官的疾病表型。因此，我们的研究建立了一个人类疾病模型和一种治疗 NPHP5-LCA 的方法。
