Generation of human chondroprogenitor cells for cartilage restoration

描述(申请人提供)：本申请旨在开发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中没有一种能在体内产生满足功能需求的持久的透明软骨替代组织。我推测人多能干细胞(PSC)来源的软骨祖细胞(CHPC)或CHPC的前体细胞可能比成人关节软骨细胞和成人间充质干细胞更有潜力用于再生医学，因为它们的软骨分化能力、谱系潜力和增殖能力。此外，我建议需要进行研究，以确定和表征人类软骨形成的各个阶段，以确保成功地从PSC中分离出完全相同的CHPC。因此，这项拟议研究的总体目标是确定从多能中胚层祖先产生CHPC的各个阶段，最终目标是产生具有最大潜力用于再生医学的CHPC。我们小组最近报道了在人类PSC分化过程中产生的最早的胚胎中胚层祖细胞(EMP)。EMP是更多谱系受限的间充质祖细胞(成骨和软骨源性)、血液内皮祖细胞和心血管祖细胞的祖先。我将用这个新的EMP群体来概括胚胎间充质形成的早期阶段，软骨形成，最终关节软骨的形成。我还在人类胚胎发育的早期阶段对初级CHPC进行了初步的免疫表型鉴定。结合对原代和诱导PSC来源的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被用于以下特定目的，以研究IPSC来源的CHPC用于再生医学的潜力。这份申请是由Denis Evseenko博士提交的，他是发育和干细胞生物学领域的一名研究员，他的目标是过渡到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等新领域的培训。此外，该提案概述了通过加州大学洛杉矶分校NIH资助的K30计划和其他培训活动开展的课程工作，这些活动将帮助Denis增加他的知识库，提高他的拨款撰写技能和执行转化性临床研究的能力。这项申请得到了加州大学洛杉矶分校整形外科研究医院的大力支持。加州大学洛杉矶分校整形外科研究部副主席兼整形外科医院研究中心主任约翰·亚当斯博士将担任这一申请的主要导师。总而言之，这项申请不仅将有助于解决软骨形成领域中当前和长期的科学问题，还将有助于Evseenko博士的职业发展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.