Ocular surface epithelial precursors

眼表面上皮前体细胞

• 批准号: 8435518
• 负责人: JOSE MARIO WOLOSIN
• 金额: $ 40.26万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-01-15 至 2016-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8435518
• 关键词: Affect; Autoimmune Process; Basal Cell; Biological Preservation; Blindness; Calcium; Cell Cycle; Cell Separation; Cell Survival; Cells; Chemical Injury; Clonality; Cornea; ES01; Epithelial; Epithelial Cells; Epithelium; Event; Fostering; Funding; G0 Phase; Gene Expression; Gene Expression Microarray Analysis; Gene Expression Profile; Generic Drugs; Genes; Genetic; Genetic Transcription; Goals; Grant; Growth; Human; In Vitro; Infection; Knowledge; Lead; MEIS1 gene; MSX1 gene; MXD1 gene; Mammals; Methodology; Nature; Operative Surgical Procedures; Outcome; Phenotype; Phosphorylation; Population; Procedures; Proteins; Reaction; Recovery of Function; Regulation; Relative (related person); Running; SELE gene; SP1 gene; Side; Signal Pathway; Signal Transduction; Stem cell transplant; Stem cells; Surface; Syndrome; System; Techniques; Testing; Tissue-Specific Gene Expression; Tissues; Transplantation; Vision; Work; base; cell behavior; cohort; comparative; corneal epithelium; heat injury; homeodomain; improved; in vivo; insight; limbal; microbial; ocular surface; overexpression; precursor cell; protein expression; public health relevance; reconstruction; response; restoration; stem; stem cell niche; stem cell population; stemness; tissue reconstruction

DESCRIPTION (provided by applicant): Small populations of stem cells sustain the limbal-corneal and the conjunctival lineages. In the limbal-corneal system, where stem cells localize preferentially to the limbus, total or zonal damage produces epithelial limbal stem cell deficiency syndromes. In recent years, a variety of surgical stem cell transplant methodologies have been applied to reestablish the limbal stem cell niche for vision restoration. The long term goals of our studies are a) understand the functional nature of ocular surface stem cells, in particular those of the limbus; and b) apply this critical knowledge for the optimization of ex vivo limbal cell population expansion to improve surface reconstructive procedures based on transplantation of stem cell-rich cell populations. During the initial funding period of this grant we characterized small stem cell cohorts known as side populations (SPs) from both conjunctival and limbal epithelia. Our studies showed that these cells derive from cells that have been in the slow cycling state in vivo and to display several other features recognized for stem cells in vitro. Based on finding during this period we now propose, in Specific Aim1 to test the hypothesis that cell cohorts expressing CD62E or excluding mitotrakcker deep red constitute additional component of an heterogeneous stem/precursor limbal and conjunctival epithelial cell population and in Specific Aim2 to test the hypothesis that observed overexpressions of several genes capable of affecting gene transcription globally and usually referred as master or cell fate genes (PAX6, MEIS1, SIX1, MSX1, HES1 ID1, the MXD1/MAX system controlling MYC activity) contribute to cell stemness in the limbal epithelium. The knowledge acquired in the comparative characterization of the cell cohorts associated with the stem/precursor cell compartment in Aim 1, combined with the identification of gene expressions and signal pathways that are associated with preservation or loss of the stem/precursor cell state in Specific Aim 2, will provide the cogent basis to improve strategies for either maximization of stem/precursor cell yields during limbal cells expansion in vitro, or alternatively, facilitate stem cell rescue from generic proliferative (basal) epithelial cells through reversion of phenotype for the benefit of reconstructive ocular surface procedures. Specific aim 3 seeks to apply the knowledge and expertise acquired in the two previous specific aims for the genetic and/pharmacological manipulation of freshly isolated limbal epithelial cells to attain effective expansion of these cells while maintaining their capacity for corneal epithelial function recovery in vivo.

描述(申请人提供)：少量干细胞支持角膜缘-角膜和结膜血统。在角膜缘-角膜系统中，干细胞优先定位于角膜缘，完全或带状损伤会导致上皮角膜缘干细胞缺乏综合征。近年来，各种外科干细胞移植方法被应用于重建角膜缘干细胞以恢复视力。我们研究的长期目标是a)了解眼表面干细胞，尤其是角膜缘干细胞的功能性质；b)将这一关键知识应用于优化体外角膜缘细胞群扩增，以改进基于干细胞丰富的细胞群移植的表面重建程序。在这笔赠款的最初资助期间，我们描述了结膜和角膜缘上皮中称为侧群(SP)的小型干细胞队列的特征。我们的研究表明，这些细胞来源于体内处于慢循环状态的细胞，并在体外显示出干细胞的其他几个特征。基于这一时期的发现，我们现在建议，在特定的Aim1中检验一种假说，即表达CD62E或排除mitotrakcker深红的细胞队列构成了不同的干/前体角膜缘和结膜上皮细胞群的额外成分；在特定的AIM2中，我们提出了一种假说，即观察到几个能够在全球范围内影响基因转录的基因的过度表达，这些基因通常被称为主基因或细胞命运基因(PAX6，Meis1，SIX1，Msx1，HEID1，控制MYC活性的MXD1/Max系统)，有助于角膜缘上皮细胞的干细胞分化。在与目标1的干细胞/前体细胞室相关的细胞队列的比较特征中获得的知识，结合对特定目标2中与干细胞/前体细胞状态的保存或丧失相关的基因表达和信号通路的鉴定，将提供令人信服的基础，以改进在角膜缘细胞体外扩增过程中最大化干细胞/前体细胞产量的策略，或者，通过逆转表型来促进干细胞从普通增殖(基础)上皮细胞中拯救出来，从而有利于重建眼表程序。具体目标3寻求应用在前两个具体目标中获得的知识和专业知识，对新鲜分离的角膜缘上皮细胞进行遗传和/或药物操作，以实现这些细胞的有效扩增，同时保持它们在体内恢复角膜上皮功能的能力。