Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada.
Invest Ophthalmol Vis Sci. 2011 Jun 1;52(6):3539-47. doi: 10.1167/iovs.10-6399.
Oculodentodigital dysplasia (ODDD) is a human disorder caused by mutations in the gap junction alpha 1 (GJA1) gene encoding the connexin43 (Cx43) gap junction protein. Causal links between GJA1 mutations and glaucoma are not understood. The purpose in this study was to examine the ocular phenotype for Gja1(Jrt/+) mice harboring a Cx43 G60S mutation. METHODS; In young Gja1(Jrt/+) mice, Cx43 abundance was assessed with a Western blot, and Cx43 localization was visualized using immunohistochemistry and confocal microscopy. Intraocular pressure (IOP) was measured by rebound tonometry, and eye anatomy was imaged using ocular coherence tomography (OCT). Hematoxylin and eosin (H&E)-stained eye sections were examined for ocular histopathology related to the development of glaucoma.
Decreased Cx43 protein levels were evident in whole eyes from Gja1(Jrt/+) mice compared with those of wild-type mice at postnatal day 1 (P = 0.005). Cx43 immunofluorescence in ciliary bodies of Gja1(Jrt/+) mice was diffuse and intracellular, unlike the gap junction plaques prevalent in wild-type mice. IOP in Gja1(Jrt/+) mice changed during postnatal development, with significantly lower IOP at 21 weeks of age in comparison to the IOP of wild-type eyes. Microphthalmia, enophthalmia, anterior angle closure, and reduced pupil diameter were observed in Gja1(Jrt/+) mice at all ages examined. Ocular histology showed prominent separations between the pigmented and nonpigmented ciliary epithelium of Gja1(Jrt/+) mice, split irides, and alterations in the number and distribution of nuclei in the retina.
Detailed phenotyping of Gja1(Jrt/+) eyes offers a framework for elucidating human ODDD ocular disease mechanisms and evaluating new treatments designed to protect ocular synaptic network integrity.
眼牙指发育不良（ODDD）是一种由连接蛋白 43（Cx43）间隙连接蛋白的缝隙连接α 1（GJA1）基因编码突变引起的人类疾病。尚不清楚 GJA1 突变与青光眼之间的因果关系。本研究的目的是检查携带 Cx43 G60S 突变的 Gja1（Jrt/+）小鼠的眼部表型。
在年轻的 Gja1（Jrt/+）小鼠中，通过 Western blot 评估 Cx43 丰度，并使用免疫组织化学和共聚焦显微镜观察 Cx43 定位。通过回弹眼压计测量眼内压（IOP），并使用眼部相干断层扫描（OCT）成像眼部解剖结构。使用苏木精和伊红（H&E）染色的眼部切片检查与青光眼发展相关的眼部组织病理学。
与野生型小鼠相比，Gja1（Jrt/+）小鼠出生后第 1 天（P = 0.005）整个眼睛中的 Cx43 蛋白水平明显降低。Gja1（Jrt/+）小鼠睫状体的 Cx43 免疫荧光呈弥漫性和细胞内性，与野生型小鼠中常见的间隙连接斑块不同。Gja1（Jrt/+）小鼠的 IOP 在出生后发育过程中发生变化，与野生型眼睛的 IOP 相比，21 周龄时的 IOP 显著降低。在所有检查的年龄中，Gja1（Jrt/+）小鼠均出现小眼球、眼球内陷、前房角关闭和瞳孔直径减小。眼部组织学显示 Gja1（Jrt/+）小鼠的色素上皮和非色素上皮睫状体之间明显分离、虹膜分裂以及视网膜中细胞核数量和分布的改变。
对 Gja1（Jrt/+）眼睛进行详细表型分析为阐明人类 ODDD 眼部疾病机制和评估旨在保护眼部突触网络完整性的新治疗方法提供了框架。
