MECHANISMS OF SKELETO-HAEMATOPOIETIC DIFFERENTIATION

骨骼造血分化机制

• 批准号: 6776660
• 负责人: Olena Jacenko
• 金额: $ 43.62万
• 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: 2000-04-01 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6776660
• 关键词: autoimmunity; bone development; bone marrow; bone marrow transplantation; cartilage development; cell differentiation; chondrocytes; collagen disorder; cytokine; electron microscopy; enzyme linked immunosorbent assay; genetically modified animals; hematopoiesis; hematopoietic stem cells; immunocytochemistry; immunosuppression; laboratory mouse; microarray technology; mixed tissue /cell culture; mucopolysaccharides; neutralizing antibody; osteoblasts; pathologic ossification; proteoglycan

DESCRIPTION (provided by applicant): Hematopoietic disorders such as bone marrow failure, immune dysfunction, and certain cancers, may involve a link between the endochondral skeleton and marrow. The objective of this renewal is to provide a mechanistic basis for the skeleto-hematopoietic link, by addressing how a hematopoietic marrow environment may form by replacement of hypertrophic cartilage by bone and marrow during endochondral ossification (EO). This proposal stems from our transgenic (Tg) and null mice for collagen X, a matrix protein expressed in hypertrophic cartilage prior to EO. Murine skeleto-hematopoietic defects include growth plate compressions, osteopenia, marrow aplasia, and altered blood cell differentiation. We propose that collagen X provides a structural network that is stabilized by proteoglycans (PGs)/glycosaminoglycans (GAGs), and sequesters cytokines. Network disruption causes redistribution of growth plate components and a cytokine imbalance; the latter may cause the hemato-poietic defects. To test this hypothesis we will: 1) Identify the defective cellular component in the marrow environment of collagen X mice by co-cultures of hematopoietic stern cells (HSCs) with stromal cells, hypertrophic chondrocytes, and osteoblasts, and test if marrow transplantation can rescue the hematopoietic defects; 2) Identify which PGs/GAGs are altered in growth plate/marrow junctions by immunohistochemistry and electron microscopy, test if they bind collagen X by affinity coelectrophoreisis, and assess the role of these interactions in hematopoiesis by co-cultures of HSCs and hypertrophic chondrocytes GAG biosynthesis modulators; 3) Examine the relationship between the severity of the skeleto-hematopoietic phenotype and dysregulated cytokine expression by macrophage cytokine production, identify the defect in immune response initiation/regulation by endotoxin challenge, ascertain dysregulated cytokines by blot arrays, identify the tissue source of aberrant cytokine production, and induce/block the disease phenotype by injection of cytokines or neutralizing antibodies; and 4) Test if other murine models with altered hypertrophic cartilage (Grg5 null & Snell dwarfs) have similar hematopoietic defects caused by cytokine dysregulation.

描述（由申请人提供）：造血性疾病，例如骨髓衰竭，免疫功能障碍和某些癌症，可能涉及内软骨骨架与骨髓之间的联系。这种更新的目的是通过解决造血骨髓环境如何通过在细胞软骨和骨髓骨骼骨骼（EO）中替换肥厚的软骨来为骨骼骨髓环境提供如何形成的机械基础。该建议源于我们的转基因（TG）和无效的胶原蛋白X，这是一种在EO之前在肥厚性软骨中表达的基质蛋白。鼠骨骼 - 毛细血管缺陷包括生长板压缩，骨质减少，骨髓性植物和血细胞分化改变。我们提出，胶原蛋白X提供了一个结构网络，该网络由蛋白聚糖（PGS）/糖胺聚糖（GAGS）稳定下来，并进行隔离细胞因子。网络破坏会导致生长板组件的重新分布和细胞因子失衡；后者可能导致血硫缺陷。为了检验该假设，我们将：1）通过与基质细胞，肥大的软骨细胞和成骨细胞的共同培养，确定胶原X小鼠骨髓环境中的缺陷细胞成分（HSC），并测试Marrow的移植能够挽救静止镇压降血性降水; 2）确定通过免疫组织化学和电子显微镜在生长板/骨髓连接中改变了哪些PGS/GAG，测试它们是否通过亲和力核核酸核心结合胶原蛋白X，并评估这些相互作用的作用，并通过HSCS和HSCS和超细质体的综合型造血质体中的作用3) Examine the relationship between the severity of the skeleto-hematopoietic phenotype and dysregulated cytokine expression by macrophage cytokine production, identify the defect in immune response initiation/regulation by endotoxin challenge, ascertain dysregulated cytokines by blot arrays, identify the tissue source of aberrant cytokine production, and induce/block the disease phenotype by injection of cytokines or neutralizing抗体； 4）测试是否其他具有改变肥厚的软骨改变的鼠模型（GRG5 NULL和SNELL矮人）具有由细胞因子失调引起的相似的造血缺陷。