GROWTH FACTOR REGULATION OF CRANIAL SUTURE MORPHOGENESIS

生长因子对颅缝形态发生的调节

• 批准号: 6176968
• 负责人: LYNNE A. OPPERMAN
• 金额: $ 10.18万
• 依托单位: TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-01 至 2003-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6176968
• 关键词: alkaline phosphatase; aminoacid metabolism; autoradiography; bone development; cell cycle; cell growth regulation; collagen; embryo /fetus tissue /cell culture; extracellular matrix; gene expression; genotype; in situ hybridization; laboratory rat; messenger RNA; neutralizing antibody; normal ossification; northern blottings; osteoblasts; osteocalcin; osteocytes; polymerase chain reaction; proline; protein biosynthesis; thymidine; transforming growth factors

Many severe craniofacial anomalies are associated with abnormal suture morphogenesis, and involve premature obliteration of sutures. Currently, the mechanisms underlying normal and abnormal suture morphogenesis are not known. TGF-beta3 was found to be essential for maintaining sutural integrity. The primary goal of these studies is to establish the mechanisms by which TGF-beta3 maintains calvarial sutures in their unossified state, yet allows them to function as bone growth centers. Since high concentrations of TGF-beta3 stimulate bone cell proliferation and collagen synthesis, important in the initial period of progression of cells to an osteoblast phenotype, the following hypothesis was formulated. For sutures to remain unossified, yet function as bone growth centers, a population of cells within the suture must remain mitogenic, replenishing cells maturing into osteoblasts. TGF-beta3 regulates cranial suture morphogenesis and maintenance of cranial sutures as bone growth centers by altering rates of cell proliferation within the suture. At high concentrations, TGF-beta3 stimulates cell proliferation and matrix production within the suture, while declining concentrations of TGF-beta3 promote maturation to an osteoblastic genotype, with matrix organization and mineralization. The following specific aims were designed to test this hypothesis: 1) test the mitogenic response of cells within the suture to TGF-beta3, 2) determine rates of extracellular matrix production by calvarial suture and bone treated with TGF-beta3, 3) test whether removal of TGF-beta3 promotes progression of cells to osteoblasts during bony obliteration of sutures and 4) confirm whether TGF-beta3 prevents osseous obliteration of rat calvarial sutures in vivo. A culture system in which fetal rat calvarial sutures undergo normal suture morphogenesis in the presence of intact dura mater, but undergo osseous obliteration in the absence of dura mater, will be used. Rates of mitogenesis and proliferating cell populations will be established by tritiated thymidine uptake. Rates of matrix production will be established by tritiated proline incorporation into collagen and non-collagen proteins. Alkaline phosphatase, Msx2 and osteocalcin production will be examined by northern blot analysis, in situ hybridization and PCR. Establishing the mechanisms by which TGF-beta3 regulates suture cell function will lead to an understanding of the role growth factors play in both normal and abnormal suture morphogenesis.

许多严重的颅面异常与异常缝合线有关 形态发生，涉及缝合线的过早闭塞。 现在， 正常和异常缝合形态发生的机制不是 已知。 发现TGF-BETA3对于维持缝合至关重要 正直。 这些研究的主要目的是建立 TGF-BETA3在其中保持钙孔缝合线的机制 未破坏的状态，但允许它们充当骨骼生长中心。 由于高浓度的TGF-BETA3刺激骨细胞增殖 和胶原蛋白合成，在最初的进展期很重要 细胞到成骨细胞表型，制定了以下假设。 为了使缝合线保持不覆盖，但充当骨生长中心的功能 缝合线内的细胞种群必须保持有丝分裂，并补充 细胞成熟成骨细胞。 TGF-BETA3调节颅缝线 形态发生和维持颅缝线作为骨生长中心 改变缝合线内细胞增殖速率。 在高 浓度，TGF-BETA3刺激细胞增殖和基质 缝合线内的生产，而TGF-BETA3浓度下降 通过基质组织促进成骨细胞基因型的成熟 和矿化。 以下特定目标旨在测试 假设：1）测试缝合线内细胞的有丝分裂反应 TGF-BETA3，2）确定通过 用TGF-BETA3，3）测试是否清除 TGF-BETA3的促进骨质促进细胞向成骨细胞的进展 缝合线的闭塞和4）确认TGF-BETA3是否阻止骨 大鼠颅骨在体内的闭塞。 一个文化系统 胎儿大鼠颅骨缝合线在正常 存在完整的硬脑膜，但在 缺少硬脑膜小母亲。 有丝分裂发生率和 增殖细胞群将通过tri胸他的胸苷建立 吸收。 矩阵生产的速率将通过tritiged建立 脯氨酸掺入胶原蛋白和非胶原蛋白中。 碱 磷酸酶，MSX2和骨钙素的产生将由北部检查 印迹分析，原位杂交和PCR。 建立机制 TGF-BETA3调节缝合细胞功能将导致 了解生长因子在正常和异常中起着作用的作用 缝合形态发生。