Stem Cells for Corneal Engineering

角膜工程干细胞

• 批准号: 9212811
• 负责人: JAMES L FUNDERBURGH
• 金额: $ 38.72万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-15 至 2019-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9212811
• 关键词: Adopted; Alpha Cell; Asses; Automobile Driving; Biomedical Engineering; Blindness; Cadaver; Cell Therapy; Cell surface; Cells; Cicatrix; Clinical; Collagen; Connective Tissue; Cornea; Corneal Injury; Corneal Opacity; Corneal Stroma; Cues; Engineering; Environment; Enzymes; Extracellular Matrix; Failure; Fibroblasts; Goals; Healthcare; Immune response; Immunosuppressive Agents; In Vitro; Individual; Knowledge; LOXL2 gene; Link; Maintenance; Mediating; Mesenchymal; Modeling; Molecular; Mus; Myofibroblast; N-Cadherin; Natural regeneration; Neutrophil Infiltration; Outcome; Penetrating Keratoplasty; Phenotype; Population; Preparation; Procedures; Property; Proteoglycan; Role; Solid; Source; Stem cells; Stromal Cells; TSG-6 protein; Testing; Therapeutic; Thick; Time; Tissue Engineering; Tissues; Transplanted tissue; Work; World Health; Wound Healing; base; blind; cadherin-11; corneal scar; crosslink; cytokine; daughter cell; experimental study; healing; human adult stem cell; human stem cells; improved; in vivo; in vivo Model; insight; macrophage; mouse model; novel; prevent; public health relevance; reconstitution; regenerative; self-renewal; stem cell population; tissue regeneration; tool

 DESCRIPTION (provided by applicant): Corneal opacity is a source of blindness for millions worldwide. Penetrating keratoplasty (PK) using cadaveric corneas is highly successful, but donated tissue is in limited supply and over time PK grafts are subject to a significant rate of complications and failure. Developing better therapy for corneal opacity is world health-care need that has inspired this project. In the 10 years of this project we have identified stem cells from human corneal stroma (CSSC) and showed that these cells (a) differentiate to keratocytes, (b) produce corneal stromal tissue in vitro, and (c) prevent formation of corneal scars in mouse models in vivo. The long-term goal of the project is develop stem cell-based therapeutic applications that can treat or reverse corneal scarring reducing the need for PK. In the renewal of the project we will work toward this goal with three specific aims. CSSC but no other stromal cells express N-cadherin (NCad). Aim 1 will test the hypothesis that NCad identifies a population of cells with keratocyte differentiation potential and provides a cell surface marker useful for isolating cells with high potential to effect corneal regeneration. We have found that CSSC can secrete connective tissue with aligned collagen and proteoglycans similar to corneal stroma. Aim 2 will test the role of microstructure topology and stiffness of solid substrates in directing the composition and organization of this CSSC-secreted matrix. The aim will also test the role of collagen crosslinking enzymes LOXL2 and TGM2 in increasing the strength and stiffness of the matrix elaborated by CSSC. This aim will assemble multilamellar constructs by stacking of the engineered tissue sheets. These experiments will provide insights on how the 3D environment directs secretion and organization of transparent stromal tissue. We have recently shown that CSSC instilled in healing corneal wounds prevent scarring and reconstitute ablated tissue with matrix indistinguishable from native cornea. Aim 3 will investigate how CSSC induce this tissue regeneration. CSSC reduce infiltration of neutrophils and induce the presence of TGFß3, a cytokine attributed to induce scarless wound healing. This aim will test the hypothesis that via secretion of TSG-6 protein, CSSC reduce neutrophil infiltration and influence macrophages to adopt an alternative activated (M2) phenotype stimulating tissue regeneration by secretion of TGFß3. The impact of these studies will be identification of novel molecular mechanisms controlling corneal stromal tissue matrix synthesis and organization. Of particular potential significance is identification of a mechanism to induce regeneration of native mammalian tissue. There will also be progress toward the goal of clinical use of CSSC. Thicker, stronger, and more organized tissue constructs will be produced with increased potential for use in lamellar grafts. Identification of properties linked to immunosuppressive and regenerative potential for CSSC will improve potential for use of these cells in cell-based therapy.

 描述（由申请人提供）：角膜混浊是全世界数百万人失明的一个原因。使用尸体角膜进行穿透性角膜移植术 (PK) 非常成功，但捐赠的组织供应有限，而且随着时间的推移，PK 移植物会出现很高的并发症。开发更好的角膜混浊治疗方法是世界卫生保健的需求，这激发了这个项目的灵感。在这个项目的 10 年里，我们已经从人类角膜基质中鉴定出了干细胞。 （CSSC）并表明这些细胞（a）分化为角膜细胞，（b）在体外产生角膜基质组织，以及（c）在体内预防小鼠模型中角膜疤痕的形成该项目的长期目标是开发。基于干细胞的治疗应用可以治疗或逆转角膜疤痕，减少 PK 的需要。在项目的更新中，我们将通过三个具体目标来实现这一目标，但没有其他基质细胞表达 N-钙粘蛋白 (NCad)。目标 1 将检验以下假设：NCad 识别具有角膜细胞分化潜力的细胞群，并提供细胞表面标记，可用于分离具有影响角膜再生的高潜力的细胞。我们发现 CSSC 可以分泌与组织排列相似的胶原蛋白和蛋白聚糖。目标 2 将测试固体基质的微观结构拓扑和刚度在指导 CSSC 分泌基质的组成和组织中的作用。胶原交联酶 LOXL2 和 TGM2 可以增加 CSSC 精心设计的基质的强度和刚度，该目标将通过堆叠工程组织片来组装多层结构，这些实验将为 3D 环境如何指导透明基质的分泌和组织提供见解。我们最近表明，在愈合角膜伤口时注入 CSSC 可以防止疤痕形成，并使用与天然角膜没有区别的基质重建消融组织。将研究CSSC如何诱导这种组织再生，CSSC如何减少中性粒细胞浸润并诱导TGFβ3的存在，TGFβ3是一种导致无疤痕伤口愈合的细胞因子，该目标将检验CSSC通过分泌TSG-6蛋白减少中性粒细胞浸润并促进组织再生的假设。影响巨噬细胞采用替代激活（M2）表型，通过分泌 TGFβ3 刺激组织再生。这些研究的影响将是确定控制角膜的新分子机制。基质组织基质的合成和组织具有特别潜在的意义，即诱导天然哺乳动物组织再生的机制也将在生产更厚、更强、更有组织的组织结构方面取得进展。与 CSSC 的免疫抑制和再生潜力相关的特性的鉴定将提高这些细胞在细胞治疗中的应用潜力。