Role of transcription factor activating protein-2 beta (AP-2β) in corneal epithelial cell fate determination and stratification

转录因子激活蛋白 2 beta (AP-2β) 在角膜上皮细胞命运决定和分层中的作用

• 批准号: 10683400
• 负责人: Judith A West-Mays
• 金额: $ 14.82万
• 依托单位: MCMASTER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10683400
• 关键词: ATF2 gene; Address; BMP4; Birth; Blindness; Bone Morphogenetic Proteins; Burn injury; Cells; Chemicals; Communication; Conjunctival Epithelium; Cornea; Corneal Endothelium; Corneal Neovascularization; Corneal Opacity; Corneal Stroma; Data; Defect; Development; Disease; Epithelial Cells; Epithelium; Exhibits; Eye Development; Genetic Diseases; Human; Immunohistochemistry; Impairment; Infection; Inflammation; Injury; Invaded; Investigation; Irido-corneo-trabecular dysgenesis; Keratin; Knockout Mice; Label; Limbus Corneae; Maintenance; Mediating; Mesenchymal; Mesenchyme; Molecular Genetics; Mus; Mutant Strains Mice; Nature; Neural Crest; Neural Crest Cell; Nuclear; Pathogenesis; Pathologic; Pathology; Pattern; Peripheral; Phenotype; Physiologic pulse; Play; Population; Population Distributions; Population Dynamics; Proteins; Reagent; Reporting; Resources; Role; Series; Signal Pathway; Signal Transduction; Signaling Protein; Stratification; Stratified Epithelium; Stromal Cells; Surface; System; Techniques; Testing; Thinness; Topical application; Vascularization; WNT Signaling Pathway; beta catenin; bone morphogenetic protein 4; cell stroma; cell type; comparison control; corneal epithelial stem cells; corneal epithelium; daughter cell; epithelial stem cell; experimental study; gene regulatory network; innovation; keratin 12; limbal; mouse model; mutant; neovascularization; ocular surface; pluripotency; population migration; radiation burn; recombinase; single-cell RNA sequencing; stem cell biology; stem cell biomarkers; stem cell differentiation; stem cell niche; stem cell population; stem cells; transcription factor; treatment strategy

Corneal surface pathologies such as corneal conjunctivalization arise mainly from the loss of limbal epithelial stem cells (LESCs) and can lead to corneal neovascularization, opacity and ultimately, blindness. Although the role of neural crest cells (NCC)-derived periocular mesenchyme (POM) has been established in development of the corneal stroma, its role in development of the corneal limbus and corneal epithelium has yet to be determined. It has been shown that transcription factors including activating protein-2 beta (AP-2β) play key roles in the development and differentiation of the POM. However, the role of AP-2β in POM-mediated corneal epithelial development remains largely unknown, as AP-2β null mice die soon after birth. To address this, we have specifically deleted AP-2β in the NCC of mice, using the Wnt1Cre-recombinase system (AP-2β NCC KO). Two major defects observed in these mice were corneal thinning and vascularization and contributing to this phenotype were an absence of the corneal endothelium and impairment in corneal epithelial stratification. Our scRNA-seq analyses along with RNAscope and immunohistochemistry revealed an absence of keratin-12 (K12), a corneal epithelial marker, and expansion of keratin-15 (K15) and K13, conjunctival epithelial specific markers, into the corneal epithelium of the mutant when compared to controls. Further investigations revealed an absence of ABCB5, a LESC marker, from the limbal region of the mutants indicating a conjunctival-like phenotype due to the absence of AP-2β in the NCC. In addition, bone morphogenetic protein (BMP) 4, a key player in corneal mesenchymal-to-epithelial signaling known to be modulated by Wnt/β-catenin during corneal epithelial stratification, was absent in the epithelium of the mutants further suggesting a crucial role of AP-2β in regulating corneal epithelial cell fate and stratification. Thus, our overarching hypothesis is that expression of AP-2β in the POM is critical for corneal epithelial cell fate determination and stratification through modulation of the Wnt/β-catenin signaling pathway. In the current proposal we aim to determine: 1) the developmental timing and fate of LESC in the AP-2β NCC KO mutants and 2) whether Wnt/β-catenin/BMP4 –signaling axis-is disrupted in the mutant and contributes to the ocular surface defects. Overall, these studies will contribute to our understanding of the gene regulatory network (GRN) controlling corneal epithelial cell fate determination and stratification, and the pathogenesis of diseases marked by corneal thinning, neovascularization and opacification.

角膜表面病变，如角膜结膜炎，主要是由角膜缘上皮的丧失引起的