Generation of human chondroprogenitor cells for cartilage restoration

描述（由申请人提供）：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。目前没有一种软骨修复策略能够产生持久的透明软骨替代组织，以满足体内对该组织的功能需求。我假设，基于其成软骨承诺、谱系潜力和增殖能力，人类多能干细胞（PSC）衍生的软骨祖细胞（ChPC）或ChPC的前体可能比成人关节软骨细胞和成体间充质干细胞在再生医学中具有更大的应用潜力。我进一步提出，需要进行鉴定和表征人类软骨形成阶段的研究，以确保从PSC中成功产生和分离相同的ChPC。因此，本研究的总体目标是确定多能中胚层祖先产生ChPC的阶段，最终目标是产生具有最大再生医学应用潜力的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是谱系受限的间充质祖细胞（成骨细胞和软骨细胞）、血内皮细胞和心血管祖细胞的祖先。我将用这个新的EMP种群来概括胚胎间质生成、软骨形成和最终关节软骨形成的早期阶段。我还在人类胚胎发生的早期阶段对原发性ChPC进行了中试免疫表型表征。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在再生医学中的应用潜力。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，其目标是过渡到一名独立研究员。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，该提案概述了通过美国国立卫生研究院资助的加州大学洛杉矶分校K30项目和其他培训活动的课程工作，这将帮助丹尼斯增加他的知识基础，提高他的拨款写作技巧和执行转化临床研究的能力。这项申请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外科研究部副主任和骨科医院研究中心主任，他将担任这项应用的主要导师。总之，这一申请不仅有助于解决软骨形成领域的近期和长期科学问题，而且有助于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. PUBLIC HEALTH RELEVANCE: Degenerative joint disease or osteoarthritis (OA) is a group of mechanical abnormalities involving degradation of joints, including articular cartilage and subchondral bone. According to the National Arthritis Data Workgroup, OA affected 26.9 million adults in 2005 in the United States, and the number is projected to increase up to 40% by 2030, therefore making joint surface restoration a priority. This application is highly relevant to the field of health science because it's designed to develop new therapeutic approaches for cartilage restoration, which in turn will reduce morbidity and mortality from degenerative joint disease.