MOLECULAR GENETICS OF PROGRESSIVE OSSEOUS HETEROPLASIA

进行性骨异质发育的分子遗传学

• 批准号: 6825223
• 负责人: EILEEN M SHORE
• 金额: $ 34.87万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6825223
• 关键词: DNA methylation; adipocytes; biological signal transduction; bone development disorder; cell differentiation; cell line; clinical research; embryonic stem cell; family genetics; gene expression; gene mutation; gene targeting; genetic disorder; genetic polymorphism; genetic regulation; genetically modified animals; guanine nucleotide binding protein; human subject; laboratory mouse; messenger RNA; nucleic acid sequence; osteoblasts; pluripotent stem cells; polymerase chain reaction; site directed mutagenesis

DESCRIPTION (provided by applicant): Genetic disorders of osteogenesis provide valuable insight into the regulation of bone formation. Progressive osseous heteroplasia (POH) is a rare and disabling genetic disorder in which the body produces bone in skin, fat and skeletal muscle. Gene mutations in POH patients inactivate one of the two copies of the GNAS gene and alter the fate of cells to cause bone formation in inappropriate locations (heterotopic ossification). GNAS encodes the G(s)alpha protein, which couples signaling via cell surface receptors to intracellular second messengers, however the specific effects of these mutations on bone cell differentiation are unknown. Ectopic bone formation in POH patients often arises within subcutaneous fat, suggesting a close, perhaps reciprocal, relationship between bone and fat cell differentiation. In addition to continuing investigations of GNAS inheritance and expression in POH, a primary goal of this proposal is to examine the effects of heterozygous inactivating GNAS mutations on bone (osteoblast) and fat (adipocyte) cell differentiation. We hypothesize that: (1) Heterozygous inactivating mutation of the GNAS gene alters cellular signaling that directs osteoblast and/or adipocyte differentiation, and (2) The complex phenotypic consequences of inactivating GNAS mutations are influenced by maternal/paternal inheritance of GNAS. The following Specific Aims will be conducted: 1. Investigate the parental origin of the GNAS allele that carries GNAS mutations in POH patients. 2. Examine POH genomic DNA for methylation characteristic of imprinting at the GNAS locus. 3. Examine the differential expression of GNAS mRNAs during osteoblast and adipocyte differentiation. 4. Examine the effects of heterozygous GNAS gene inactivation on osteoblast and adipocyte differentiation. 5. Investigate the effects of an inactive GNAS gene on expression of specific GNAS transcripts during osteoblast and adipocyte differentiation. The overall goal of this project is to characterize the role of the GNAS gene in the regulation of bone cell differentiation. The studies described in this proposal will provide the foundation to examine the specific pathways through which GNAS regulates osteogenesis. These investigations will provide important information for developing diagnostic and treatment strategies for a wide range of disorders of bone such as POH and more common conditions.

描述（由申请人提供）：成骨的遗传性疾病为骨形成的调节提供了有价值的见解。进行性骨异型增生 (POH) 是一种罕见的致残性遗传性疾病，身体会在皮肤、脂肪和骨骼肌中产生骨骼。 POH 患者的基因突变使 GNAS 基因的两个拷贝之一失活，并改变细胞的命运，导致不适当位置的骨形成（异位骨化）。 GNAS 编码 G(s)alpha 蛋白，该蛋白通过细胞表面受体将信号传导与细胞内第二信使耦合，但这些突变对骨细胞分化的具体影响尚不清楚。 POH 患者的异位骨形成通常发生在皮下脂肪内，表明骨和脂肪细胞分化之间存在密切的、也许是相互的关系。除了继续研究 POH 中的 GNAS 遗传和表达之外，该提案的主要目标是检查杂合失活 GNAS 突变对骨（成骨细胞）和脂肪（脂肪细胞）细胞分化的影响。我们假设：（1）GNAS 基因的杂合失活突变改变了指导成骨细胞和/或脂肪细胞分化的细胞信号传导，（2）失活 GNAS 突变的复杂表型后果受到 GNAS 母系/父系遗传的影响。将进行以下具体目标： 1. 调查 POH 患者中携带 GNAS 突变的 GNAS 等位基因的亲本起源。 2. 检查 POH 基因组 DNA 的 GNAS 基因座印迹甲基化特征。 3.检查成骨细胞和脂肪细胞分化过程中GNAS mRNA的差异表达。 4. 检查杂合 GNAS 基因失活对成骨细胞和脂肪细胞分化的影响。 5. 研究失活的 GNAS 基因对成骨细胞和脂肪细胞分化过程中特定 GNAS 转录物表达的影响。该项目的总体目标是表征 GNAS 基因在骨细胞分化调节中的作用。该提案中描述的研究将为检查 GNAS 调节成骨的具体途径提供基础。这些研究将为制定针对各种骨疾病（例如 POH 和更常见疾病）的诊断和治疗策略提供重要信息。