Hu Leyi, Ma Jingyu, Guo Jingyi, Liang Huilin, Zhang Ke, Tan Xuhua, Liu Zhenzhen, Luo Lixia, Liu Yizhi, Chen Shuyi
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China.
Invest Ophthalmol Vis Sci. 2025 Jul 1;66(9):45. doi: 10.1167/iovs.66.9.45.
Lens development requires tight regulation of cell proliferation and differentiation processes, the disruption of which might lead to congenital cataract formation. N6-methyladenosine (m6A) is the most prevalent mRNA internal modification and has been shown to play important roles in regulating the development, physiology, and pathology of various organs and tissues. However, the function of m6A during lens development remains unknown. The purpose of this study was to investigate the function of Mettl3, the core catalytic component of the m6A-writer complex, during lens development.
Lens-specific Mettl3 conditional knockout (Mettl3-CKO) mice were used as a model to investigate the function of Mettl3 during lens development. Hematoxylin and eosin staining was used to examine lens histology. Immunofluorescence (IF) staining was used to examine the expression of genes in the lenses. RNA sequencing (RNA-seq) was used to characterize the transcriptome of the lenses. Modified m6A sequencing was used to characterize the m6A epitranscriptome of the lenses.
Mettl3-CKO mice developed cataracts; histologic and IF examination revealed that Mettl3-CKO lenses presented defects in several secondary fiber differentiation processes, including delayed cell cycle exit, mislocalization, and failed cell body elongation. RNA-seq revealed that the expression of genes regulating actin-cytoskeleton dynamics and cell cycle progression was altered in Mettl3-CKO lenses. m6A-seq characterized the lens m6A epitranscriptome and suggested its potential role in regulating fiber cell differentiation processes.
Mettl3 regulates lens development by promoting the cell cycle exit and cell morphological changes during secondary lens fiber differentiation.
晶状体发育需要严格调控细胞增殖和分化过程，这些过程的破坏可能导致先天性白内障的形成。N6-甲基腺苷（m6A）是最普遍的mRNA内部修饰，已被证明在调节各种器官和组织的发育、生理和病理过程中发挥重要作用。然而，m6A在晶状体发育过程中的功能仍不清楚。本研究的目的是探讨m6A书写复合体的核心催化成分Mettl3在晶状体发育过程中的功能。
使用晶状体特异性Mettl3条件性敲除（Mettl3-CKO）小鼠作为模型，研究Mettl3在晶状体发育过程中的功能。苏木精-伊红染色用于检查晶状体组织学。免疫荧光（IF）染色用于检查晶状体中基因的表达。RNA测序（RNA-seq）用于表征晶状体的转录组。修饰的m6A测序用于表征晶状体的m6A表观转录组。
Mettl3-CKO小鼠出现白内障；组织学和IF检查显示，Mettl3-CKO晶状体在几个次级纤维分化过程中存在缺陷包括细胞周期退出延迟、定位错误和细胞体伸长失败。RNA-seq显示，在Mettl3-CKO晶状体中，调节肌动蛋白细胞骨架动力学和细胞周期进程的基因表达发生了改变。m6A-seq表征了晶状体m6A表观转录组，并提示其在调节纤维细胞分化过程中的潜在作用。
Mettl3通过促进晶状体次级纤维分化过程中的细胞周期退出和细胞形态变化来调节晶状体发育。
