HERITABLE DISORDERS OF CONNECTIVE TISSUE

该科继续进行旨在阐明分子的研究。 结缔组织遗传性疾病的机制，特别是 成骨不全(OI)和Ehler-Danlos(EDS)及其应用 这一信息有助于这些疾病的治疗。 该部门的一个持续兴趣是确定胶原蛋白 OI和EDS患者的基因突变及其相关性研究 突变的类型和位置与疾病的严重程度 结缔组织紊乱。α2(I)胶原链的突变 由本部分和其他实验室确定，提供了其他 支持我们提出的区域模式。 该科有三个主要项目。其中一个主要项目是 选择性反义抑制突变的胶原等位基因 作为一种治疗干预的方法。今年我们求助于 反义锤头状核酶的使用。在体外，我们已经证明 等位基因特异性切割，并确定了切割参数。我们 进行了总RNA和人工合成的竞争实验 目标。我们现在正在研究向量构造来确定抑制 在培养细胞中的稳定性和效率。 第二个主要项目是产生一个小鼠模型 非致命性OI。我们已经使用定点突变技术生产了一种 用模仿非致死性人类OI的点突变构建。这个 将使用CRE-LOX重组系统来控制 突变的表达和lox-Stop-lox构建 被引入内含子之前的外显子 致病突变。我们已经分离了重组的ES细胞，并有 成功地产生了嵌合体。 我们一直在开发的第三个主要关注焦点是 OI的骨生物学。我们正在使用培养的成骨细胞来研究 骨细胞修饰和分泌突变的胶原蛋白。我们还在追求 输卵管基质继发性非胶原性异常及其治疗反应 OI成骨细胞对转化生长因子β的刺激。 在临床研究中，我们正在继续我们的生长治疗试验。 OI矮小儿童体内激素对生长发育的影响 刺激、骨密度和骨形态计量学特性。我们是 继续我们在OI的神经学方面的合作兴趣 在最大化OI儿童的身体功能方面， 积极的康复。

The Section has continued its studies aimed at elucidating the molecular mechanisms of heritable disorders of connective tissue, specifically osteogenesis imperfecta (OI) and Ehlers-Danlos (EDS), and at applying this information to the treatment of these disorders. One continuing interest of the Section is to identify the collagen mutations in patients with OI and EDS and determine the relationship between the type and location of the mutation and the severity of the connective tissue disorder. Mutations in the alpha2(I) collagen chain identified by this Section and other labs have provided additional support for the regional model we have proposed. There are three primary projects in the Section. One primary project is to develop selective antisense suppression of the mutant collagen allele as an approach for therapeutic intervention. This year we have turned to the use of antisense hammerhead ribozymes. In vitro, we have demonstrated allele- specific cleavage and determined the parameters for cleavage. We have conducted competition experiments with total RNA and synthetic targets. We are now pursuing vector constructs to determine suppression stability and efficiency in cultured cells. The second primary project is the generation of a murine model for non-lethal OI. We have used site-directed mutagenesis to produce a construct with a point mutation mimicking non-lethal human OI. The cre-lox recombination system will be used to control the timing of expression of the mutation and a lox-stop-lox construct has been introduced into the intron prior to the exon containing the disease-causing mutation. We have isolated recombinant ES cells and have successfully generated chimeras. A third major focus of interest which we have been developing is in the bone biology of OI. We are using cultured osteoblasts to study the way bone cells modify and secrete mutant collagen. We are also pursing the secondary non-collagenous abnormalities of OI matrix and the response of OI osteoblasts to TGF-beta stimulation. In clinical studies, we are continuing our treatment trial of growth hormone in short children with OI to determine its effects on growth stimulation, bone density and bone morphometric properties. We are continuing our collaborative interests in the neurological aspects of OI and in maximizing the physical functioning of OI children though aggressive rehabilitation.