New Insights into the Ocular Surface in Health and Disease

 描述（由申请方提供）：结膜杯状细胞是合成和分泌粘蛋白以维持眼表面完整性的主要细胞类型。由于杯状细胞异常导致泪膜中粘蛋白的缺乏，从而引起干眼症，严重影响人们的视力和生活。缺乏关于结膜上皮细胞分化形成杯状细胞的调节机制的知识阻碍了DES治疗方案的开发。我们发现，在小鼠模型中，通过眼表上皮细胞（OSdnMAML 1）中显性负性转录辅激活因子mastermud-like 1（dnMAML 1）的条件性表达抑制Notch抑制杯状细胞分化。与野生型小鼠（OSWt）相比，OSdnMAML 1的眼表面表现出结膜上皮增生、异常脱屑和杯状细胞形成受损。此外，OSdnMAML 1抑制Krüppel样转录因子4和5基因（Klf 4和Klf 5）的表达和Muc 5/ac的合成。相反，在TGF β RII条件性敲除（cKO）的整个眼睑基质中，结膜上皮细胞扩增并分化为杯状细胞。 小鼠扩增的TGF β RIIcKO结膜上皮强烈表达SAM指向结构域的ETS转录因子（SPDEF），其在多个器官的杯状细胞分化中起关键作用。我们假设，固有的经典Notch和TGF β信号通路及其相互作用在结膜杯状细胞分化中起关键作用。我们提出了三个目标来检验这一假设。 目的1：阐明Jagged 1/Notch 1 N1-ICD/Rbp-jκ MAML 1 Klf 4/5 Muc 5/ac轴在结膜杯状细胞分化中的作用。 目的2：阐明TGF β R Ⅱ、Smads、SPDEF、Muc 5/ac轴在杯状细胞分化中的作用。 目的3：描述Notch和TGF β 1通路如何相互作用以产生平衡杯状细胞分化的生理输出。

 DESCRIPTION (provided by applicant): Conjunctival goblet cells are the major cell type that synthesize and secrete mucins for the maintenance of ocular surface integrity. Lack of mucins in the tear film due to goblet cells abnormality causes dry eye syndrome (DES) and affects millions of people's vision and life. The lack of knowledge regarding the regulatory mechanisms by which conjunctival epithelial cells differentiate to form goblet cells hampers the development of treatment regimens for DES. We found that inhibition of Notch via conditional expression of a dominant negative transcriptional coactivator mastermind-like 1 (dnMAML1) in the ocular surface epithelia (OSdnMAML1) suppressed goblet cell differentiation in mouse model. Compared to the wild-type mouse (OSWt), the ocular surface of the OSdnMAML1 exhibited conjunctival epithelial hyperplasia, aberrant desquamation, and impaired goblet cell formation. Moreover, OSdnMAML1 inhibited Krüppel-like transcriptional factor 4 and 5 genes (Klf4 and Klf5) expression and Muc5/ac synthesis. In contrast, conjunctival epithelium was expanded and differentiated into goblet cells in entire eyelid stroma of the TGFßRII conditional knockout (cKO) mice. The expanded TGFßRIIcKO conjunctival epithelium strongly expressed SAM-pointed domain containing ETS transcription factor (SPDEF), which plays a critical role in goblet cell differentiation in multiple organs. We hypothesize that intrinsic canonical Notch and TGFß signaling pathways and their interaction(s) play pivotal roles in conjunctival goblet cell differentiation. We propose three aims to test this hypothesis. Aim 1: To elucidate that Jagged1/Notch1 N1-ICD/Rbp-jκMAML1 Klf4/5 Muc5/ac axis is critical for the conjunctival goblet cell differentiation. Aim 2: To elucidate that TGFßRII Smads SPDEF Muc5/ac axis has a role in goblet cell differentiation. Aim 3: To delineate how Notch and TGFß pathways interact to come up with a physiological output for balanced goblet cell differentiation.