TYPE II COLLAGEN ISOFORMS IN CRANIOFACIAL SKELETOGENESIS

颅面骨骼发育中的 II 型胶原蛋白异构体

• 批准号: 2897101
• 负责人: HYUN-DUCK NAH-CEDERQUIST
• 金额: $ 11.76万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-05-01 至 2001-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2897101
• 关键词: Baculoviridae; RNA splicing; antibody; bone development; cartilage; chick embryo; chondrocytes; collagen; craniofacial; fibrinogen; gene expression; immunocytochemistry; immunoelectron microscopy; immunoprecipitation; mesenchyme; myofibrils; osteogenesis; procollagen; protein biosynthesis; protein isoforms; protein purification; protein structure function; synthetic peptide; tissue /cell culture; transfection /expression vector

DESCRIPTION (Adapted from the Applicant's Abstract): The overall goal of this R29 application is to understand whether differential expression of alternatively spliced type II procollagen isoforms is necessary for the normal development of craniofacial cartilage and bone. Previous work by the Principal Investigator in the chick, and by others in different species, has shown that the type II collagen gene encodes two isoforms of mRNA that are the result of alternative splicing and that are expressed differentially during skeletogenesis. One form (IIA) includes exon 2 that encodes a cysteine-rich globular domain of the amino (N)-propeptide and is expressed in prechondrogenic mesenchyme and embryonic calvaria at low levels. The type IIB gene excludes exon 2, and is expressed at high levels by well-differentiated chondrocytes. The change in splicing pattern during chondrogenesis is accompanied by markedly increased type II collagen mRNA levels resulting in deposition of type II collagen-containing cartilage matrix. The proposed studies will address the hypotheses that (1) the cysteine-rich globular domain of type IIA procollagen functions in maintaining low levels of type II collagen synthesis in embryonic calvaria as well as prechondrogenic mesenchyme by a negative feedback mechanism, and thus splicing out of this domain is a necessary step for upregulation of type II collagen synthesis during cartilage formation, and (2) type IIA procollagen regulates fibrillogenesis in embryonic calvaria by forming heterotypic fibrils with type I collagen. The specific aims are: (1) To investigate the role of the alternatively spliced cysteine-rich globular domain in regulation of type II collagen production in chondrocytes and calvarial cells; (2) To define the role of type IIA procollagen in fibrillogenesis in developing calvaria; and (3) To analyze the effects of targeted overexpression of type IIA procollagen N-propeptide and abrogation of type IIA procollagen in the developing craniofacial skeleton of chick embryos using replication-competent retroviral (RCAS) constructs. These studies should strengthen our understanding of normal and abnormal development of the craniofacial skeleton.

描述（根据申请人的摘要改编）： 此R29应用是要了解是否差异表达 或者，剪接的II型Procollagen同工型对于 颅面软骨和骨骼的正常发育。 以前的工作 小鸡和其他物种中的其他研究人员 表明II型胶原蛋白基因编码mRNA的两个同工型 替代剪接和差异表达的结果 在骨骼发生期间。 一种形式（IIA）包括编码A的外显子2 氨基（n）甲状腺素的富含半胱氨酸的球状结构域并表示 在较低水平的前生物学间充质和胚胎钙质中。 这 IIB型基因不包括外显子2，并以高水平表示 分化良好的软骨细胞。 剪接模式的变化 软骨发生伴随着明显增加的II型胶原mRNA 导致沉积II型胶原蛋白软骨的水平 矩阵。 拟议的研究将解决（1） IIA型Procollagen功能的富含半胱氨酸的球状域 维持胚胎伊拉尼亚省的II型胶原蛋白合成较低 以及通过负反馈机制和 因此，从该域中剪接是上调的必要步骤 软骨形成期间II型胶原蛋白合成，（2）IIA型 Procollagen通过形成胚胎钙调节的原纤维生成 带有I型胶原蛋白的异型原纤维。 具体目的是：（1） 研究富含半胱氨酸的球状的作用 在软骨细胞中的II型胶原蛋白产生调节中的结构域和 钙细胞； （2）定义IIA型Procollagen的作用 在发育中的瓦尔瓦里亚的原纤维生成； （3）分析 IIA型Procollagen N-肽和废除的靶向过表达 雏鸡发育中的颅面骨骼中的IIA型胶原素 使用竞争能力逆转录病毒（RCAS）构建体的胚胎。 这些 研究应加强我们对正常和异常的理解 颅面骨骼的发展。