REGULATION OF BMP-6 IN EARLY OSTEOBLAST DIFFERENTIATION

描述（改编自申请人的摘要）： 成骨细胞的分化涉及多个系统、旁分泌和自分泌的过程， 因素 其中最关键的是骨形态发生蛋白 （BMP）。 BMP是一个局部活跃的生长和分化家族， 大多数成员能够诱导和调节骨细胞 分化 申请人对糖皮质激素（GC）的研究 早期成骨细胞分化的增强导致了以下假设： BMP-6具有独特的重要作用。 本建议的重点是 了解BMP-6的作用和调节机制 在早期成骨细胞分化过程中表达。 据推测 结论：（1）BMP-6的表达是成骨细胞启动所必需的 （2）BMP-6表达的GC调节发生在 主要通过翻译前机制;和（3）一个特定的区域， BMP-6启动子是表达BMP-6基因GC调控所必需的 表情 BMP-6启动成骨细胞的需要 将通过证明BMP-6反义寡核苷酸 寡核苷酸阻断GC诱导的分化;这表明， 加入外源性BMP-6应该恢复正常的分化， 用BMP-6反义寡核苷酸处理的培养物。 翻译前 BMP-6表达的调节将通过测量GC诱导的 BMP-6 mRNA合成和稳定性的变化。 最后， BMP-6基因将被鉴定，并且所需的特异性区域为 确定BMP-6转录的GC增强。 这个地区将成为 与BMP-6启动子区域相比， 在其他情况下增加BMP-6表达，包括自发性 成骨细胞分化和其他BMP的诱导。 临床 应用BMP诱导的骨形成可以增加成功的骨形成。 在具有挑战性的整形外科应用中的骨愈合，例如脊柱 融合、骨折不愈合和节段性长骨缺损。 尽管 骨形态发生蛋白在低等脊椎动物模型、骨 在非人类灵长类动物中形成需要更大的BMP剂量， 临床应用非常昂贵。 更好地理解 特定BMP的调节，以及制定策略，以提高 最关键的骨诱导因子的体内表达或活性， 会有很大的临床价值 对BMP-6的进一步了解 启动子可能导致涉及寡核苷酸治疗的策略， 病毒介导的因子递送以局部增强BMP-6的表达， 或在目标细胞群中。

DESCRIPTION (Adapted from the Applicant's Abstract): The complex process of osteoblast differentiation involves many systemic, paracrine and autocrine factors. Among the most critical are the bone morphogenetic proteins (BMPs). BMPs are a family of locally active growth and differentiation factors, with most members capable of inducing and modulating bone cell differentiation. The applicants' study of the glucocorticoid (GC) enhancement of early osteoblast differentiation has led to the hypothesis that BMP-6 has a uniquely important role. The present proposal focuses on understanding mechanisms involved in the role and regulation of BMP-6 expression during early osteoblast differentiation. It is hypothesized that: (1) BMP-6 expression is required for initiation of osteoblast differentiation; (2) the GC regulation of the BMP-6 expression occurs primarily via pretranslational mechanisms; and (3) a specific region of the BMP-6 promoter is required to convey the GC regulation of BMP-6 gene expression. The requirement for BMP-6 to initiate osteoblast differentiation will be tested by demonstrating that BMP-6 antisense oligonucleotides block GC-induced differentiation; it is suggested that addition of exogenous BMP-6 should restore normal differentiation of cultures treated with BMP-6 antisense oligonucleotides. Pretranslational regulation of BMP-6 expression will be examined by measuring GC-induced changes in BMP-6 mRNA synthesis and stability. Finally, the promoter of the BMP-6 gene will be identified and the specific region that is required for GC-enhancement of BMP-6 transcription determined. This region will be compared with the region of the BMP-6 promoter which is required for increased BMP-6 expression in other contexts, including spontaneous osteoblast differentiation and induction by other BMPs. Clinical application of the BMP-induced bone formation could increase successful healing of bone in challenging orthopedic applications, such as spine fusions, fracture nonunions and segmental long bone defects. Despite encouraging results with BMPs in lower vertebrate animal models, bone formation in nonhuman primates has required larger BMP doses, making certain clinical applications very expensive. An improved understanding of the regulation of specific BMPs, and development of strategies to enhance the in vivo expression or activity of the most critical osteoinductive factors, would have great clinical value. An increased understanding of the BMP-6 promoter may lead to strategies involving oligonucleotide therapy or viral-mediated delivery of factors to enhance expression of BMP-6 locally, or in a targeted population of cells.