Mechanistically linking skeletogenesis and hematopoiesis

这一建议将表征软骨内骨化之间的联系，软骨内骨化是肥大的软骨 取而代之的是骨骼和骨髓，以及功能性免疫系统的发展。要做到这一点，胶原X 由于疾病表型涉及生长，将使用转基因(TG)和敲除小鼠(KO)小鼠 导致骨髓环境改变和异常造血的板状缺陷。现建议： X型胶原和其他基质分子，例如糖胺多聚糖和硫酸乙酰肝素蛋白多聚糖， 提供了一个结构网络，将细胞因子隔离在肥大的软骨中，并对其进行破坏 网络可能导致生长板/骨髓连接处的不适当信号导致骨髓改变 环境和造血功能缺陷。为了测试这一点，1)骨髓住院医生的参与 X型胶原小鼠的细胞，例如基质细胞、肥大的软骨和/或成骨细胞 表型将在骨髓移植中得到确认，2)进一步，X胶原蛋白小鼠骨髓 将在体外测试支持造血的环境，测试淋巴细胞的功能， 并将单独检测骨髓驻留细胞支持造血的能力。3)最后， 将探索一种机制，将异常的细胞因子表达联系起来，这是由于 肥大网络，通过实时RT-PCR改变生长板和骨髓组织的造血功能 来自X胶原蛋白的小鼠。由此产生的数据可能会阐明造血骨髓是如何建立的，以及 骨骼缺陷可能导致骨髓改变和造血功能障碍。 了解骨骼发育和造血之间的关系可能会揭示哪些骨骼 缺陷会导致骨髓改变，导致造血障碍和免疫力受损，例如 骨髓衰竭和免疫功能障碍(如再生障碍性贫血、类风湿性关节炎)、自身免疫、AS 以及某些癌症(如白血病、淋巴瘤)。

This proposal will characterize the link between endochondral ossification, where hypertrophic cartilage is replaced by bone and marrow, and the development of a functional immune system. To do this, collagen X transgenic (Tg) and knock-out mice (KO) mice will be used since the disease phenotype involves growth plate defects, which lead to an altered marrow environment and aberrant hematopoiesis. It is proposed that collagen X and other matrix molecules, e.g. glycosaminoglycans and heparan sulfate proteoglycans, provides a structural network that sequesters cytokines in hypertrophic cartilage, and disruption of this network may cause inappropriate signaling at the growth plate/marrowjunction leading to an altered marrow environment and defective hematopoiesis. To test this, 1) The involvement of the bone marrow resident cells, e.g. stromal cells, hypertrophic cartilage, and/or osteoblasts, from the collagen X mice in the disease phenotype will be confirmed with bone marrow transplants, 2) Further, the collagen X mouse marrow environment will be assayed for support of hematopoiesis in vitro, function of lymphocytes will be tested, and the marrow resident cells will be assayed individually for the ability to support hematopoiesis. 3) Finally, a mechanism will be explored that links aberrant cytokine expression, due to decompartmentalization of the hypertrophic network, to altered hematopoiesis via real-time RT-PCR of growth plate and marrow tissue from collagen X mice. Resulting data may elucidate how a hematopoietic marrow is established, and which skeletal defects might contribute to marrow alterations and hematopoietic disorders. Understanding the relationship between skeletal development and hematopoiesis may reveal which skeletal defects contribute to marrow alterations, leading to hematopoietic disorders and impaired immunity, such as bone marrow failure and immune dysfunction (e.g. aplastic anemia, rheumatoid arthritis), autoimmunity, as well as certain cancers (e.g. leukemia, lymphoma).