Yu Ziyan, Yu Wenting, Liu Jia, Wu Danhong, Wang Chunxia, Zhang Jinsong, Zhao Jiangyue
1 Department of Ophthalmology, Fourth Affiliated Hospital of China Medical University, Eye Hospital of China Medical University, Provincial Key Laboratory of Lens Research, Shenyang, China.
2 Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
J Int Med Res. 2018 Jul;46(7):2843-2855. doi: 10.1177/0300060518774687. Epub 2018 Jun 19.
Objective To investigate the influence of Msx2 conditional gene knockout during lens development in mice. Methods Lens-specific Msx2 knockout mice were generated using the Cre-loxP system. The eyes of Msx2 conditional knockout ( Msx2CKO) and wild-type ( Msx2WT) mice were examined during embryonic and early postnatal periods using histological, immunofluorescence, in situ hybridization, cell proliferation, apoptosis, and mRNA microarray analyses. Results Msx2CKO mice exhibited small lens formation and microphthalmia after birth, while Msx2CKO embryos exhibited a persistent lens stalk, small lens formation, and microphthalmia. Conditional deletion of Msx2 also led to an increased apoptosis rate, a significant reduction in FoxE3 expression, and an upregulation of Prox1 expression in the lens vesicle during the early embryonic period. Microarray comparison of Msx2CKO and Msx2WT lens transcriptomes identified a large number of differentially expressed genes. Real-time PCR showed that Casp8 and Casp3 expression was upregulated in Msx2CKO mice at post-natal day 1. Conclusion The activation of apoptosis through the caspase-8/caspase-3 signaling pathway, together with the downregulation of FoxE3 expression, appeared to account for the smaller lens formation in Msx2CKO mice.
目的 研究Msx2条件性基因敲除对小鼠晶状体发育的影响。方法 利用Cre-loxP系统构建晶状体特异性Msx2敲除小鼠。在胚胎期和出生后早期，采用组织学、免疫荧光、原位杂交、细胞增殖、凋亡及mRNA微阵列分析等方法，对Msx2条件性敲除（Msx2CKO）小鼠和野生型（Msx2WT）小鼠的眼睛进行检测。结果 Msx2CKO小鼠出生后表现出晶状体形成小和小眼畸形，而Msx2CKO胚胎表现出持续性晶状体柄、晶状体形成小和小眼畸形。Msx2的条件性缺失还导致胚胎早期晶状体泡中凋亡率增加、FoxE3表达显著降低以及Prox1表达上调。Msx2CKO和Msx2WT晶状体转录组的微阵列比较鉴定出大量差异表达基因。实时PCR显示，出生后第1天Msx2CKO小鼠中Casp8和Casp3表达上调。结论 通过半胱天冬酶-8/半胱天冬酶-3信号通路激活凋亡，以及FoxE3表达下调，似乎是Msx2CKO小鼠晶状体形成较小的原因。
