Generation of human chondroprogenitor cells for cartilage restoration

描述（由申请人提供）：本申请旨在开发用于软骨修复的新治疗方法，从而降低退行性关节疾病的发病率和死亡率。目前的软骨修复策略都没有产生持久的透明软骨替代组织，其满足体内对该组织的功能需求。我假设，人多能干细胞（PSC）衍生的软骨祖细胞（ChPC）或前体的ChPC可能有更大的潜力，用于再生医学比成人关节软骨细胞和成人间充质干细胞的基础上，他们的软骨形成的承诺，谱系潜力和增殖能力。此外，我建议，需要研究，以确定和表征人类软骨形成的阶段，以确保成功的一代和分离相同的ChPC从PSC。因此，拟议研究的总体目标是确定从多能中胚层祖先产生ChPC的阶段，最终目标是生产具有最高再生医学潜力的ChPC。我们的小组最近报道了最早的胚胎中胚层祖细胞（EMP）在人PSC分化过程中产生。EMP是更多谱系限制的间充质祖细胞（成骨和软骨）、血内皮和心血管祖细胞的祖先。我将使用这种新的EMP人口重演胚胎间充质生成，软骨形成和最终，关节软骨形成的早期阶段。我还在人胚胎发生的早期阶段对原代ChPC进行了初步免疫表型表征。结合原代和诱导PSC（iPSC）衍生的ChPC群体的体外研究，异种移植动物模型和体内生物发光成像将用于以下特定目的，以研究iPSC衍生的ChPC用于再生医学的潜力。本申请由Denis Evseenko博士提交，他是发育和干细胞生物学领域的研究员，其目标是成为一名独立的研究人员。作为他职业发展的一部分，他将接受软骨生物学和骨关节炎异种移植模型新领域的培训。此外，该提案还概述了通过NIH资助的加州大学洛杉矶分校K30项目和其他培训活动开展的课程工作，这些活动将帮助Denis增加他的知识基础，提高他的赠款写作技能和执行转化临床研究的能力。该应用得到了加州大学洛杉矶分校骨科研究医院的大力支持。约翰亚当斯博士是加州大学洛杉矶分校骨科研究部门的副主席和骨科医院研究中心主任，他将担任本申请的主要导师。总之，这项申请不仅将解决软骨形成领域的直接和长期科学问题，还将帮助Evseenko博士成为一名成功的独立研究人员。

DESCRIPTION (provided by applicant): This application is designed to develop new therapeutic approaches for cartilage restoration, which in turn will reduce morbidity and mortality from degenerative joint disease. None of the current cartilage repair strategies has generated long lasting hyaline cartilage replacement tissue that meets functional demands placed upon this tissue in vivo. I hypothesize that human pluripotent stem cell (PSC) derived chondroprogenitor cells (ChPC) or the precursors of ChPC may have greater potential for use in regenerative medicine than adult articular chondrocytes and adult mesenchymal stem cells based on their chondrogenic commitment, lineage potential and proliferative ability. Further I propose that studies to identify and characterize the stages of human chondrogenesis are needed to insure successful generation and isolation of identical ChPC from PSC. Thus, the overall goal of the proposed study is to define the stages through which ChPC are generated from multipotent mesodermal ancestors, with the ultimate objective of producing ChPC with the highest potential for use in regenerative medicine. Our group has recently reported the earliest embryonic mesodermal progenitor (EMP) produced during human PSC differentiation. EMPs are ancestors of more lineage restricted mesenchymal progenitor cells (osteo- and chondrogenic), hematoendothelial and cardiovascular progenitors. I will use this novel EMP population to recapitulate early stages of embryonic mesenchyme generation, chondrogenesis and eventually, articular cartilage formation. I also carried out pilot immunophenotypical characterization of primary ChPC at early stages of human embryogenesis. In combination with in vitro studies of primary and induced PSC (iPSC)-derived ChPC populations, a xenograft animal model and in vivo bioluminescence imaging will be utilized in the following specific aims to study the potential of iPSC-derived ChPC for use in regenerative medicine. This application is submitted by Dr. Denis Evseenko, an investigator in the field of developmental and stem cell biology whose objective is to transition into an independent researcher. As part of his career development he will receive training in the new fields of cartilage biology and xenograft models of osteoarthritis. In addition this proposal outlines the course work through the NIH funded K30 program at UCLA and other training activities that will help Denis to increase his knowledge base and improve his grant writing skills and ability to execute translational clinical research. This application is strongly supported by the Orthopedic Research Hospital at UCLA. Dr John Adams who is a Vice Chair of Research Department of Orthopedic Surgery and Director of Orthopedic Hospital Research Center at UCLA will act as a primary mentor for this application. In summary, this application will serve not only to address immediate and long term scientific questions in the field of chondrogenesis, but also the career development of Dr Evseenko into a successful independent researcher.