Regeneration of Nucleus Pulposus by Tissue Engineering

描述（由申请人提供）： 背痛是我们社会中发病率的重要来源，与椎间盘的病理学直接相关。目前，退行性椎间盘疾病的治疗包括旨在缓解症状的保守和侵入性疗法。组织修复和干细胞生物学的最新进展有助于确定重建患病/退化组织的可能新方法。因此，本提案中描述的研究目标是开发一种基于“组织工程”的椎间盘治疗方法。调查的具体目的是：1。研究MSC向髓核样细胞的分化;评价这些工程化细胞在体外细胞和器官培养系统中的定向和命运。MSC将维持在增强分化成髓核表型的条件下。在选定的时间间隔，将评估椎间盘细胞向与髓核一致的表型的分化。我们将测试的假设，椎间盘的独特的微环境，以提高分化的MSC细胞显示髓核样表型。2.从髓核中分离出脊索细胞群，研究这些细胞对MSC向髓核表型转化的影响。我们将研究从年轻大鼠髓核中分离的脊索细胞对MSC分化和髓核样组织形成的影响。我们将共培养脊索与预分化的MSC之前，他们插入髓核腔。我们将检验这一假设，即脊索起源的细胞刺激髓核表型的表达。3.评估移植的MSC是否可以在体内用于重建大鼠髓核。悬浮在可注射的水凝胶中，我们将手术移植预分化的MSC到体内正常大鼠椎间盘的髓核腔中。我们将评估细胞的活力和它们产生髓核样组织的能力。本研究的结果将验证特定目标1和2中进行的体外研究，并允许我们测试MSC可以在体内分化为髓核样细胞的假设。从长远来看，如果成功的话，这种治疗方法将需要使用患者自己的细胞进行椎间盘再生。

DESCRIPTION (provided by applicant): Back pain, a significant source of morbidity in our society, is directly related to the pathology of the intervertebral disc. At present, the treatment of degenerative disc disease consists of therapies, both conservative and invasive, that are aimed at symptomatic relief. Recent advances in the understanding of tissue repair and stem cell biology have served to identify possible new approaches to rebuild diseased/degenerate tissues. Accordingly, the goal of the investigations described in this proposal is to develop a "tissue engineering" based approach to disc therapy. The Specific Aims of the investigation are: 1. To examine the differentiation of MSC into a nucleus pulposus-like cell; to evaluate the commitment and fate of these engineered cells in an in vitro cell and organ culture system. MSC will be maintained under conditions that enhance differentiation into a nucleus pulposus phenotype. At selected time intervals, differentiation of the disc cells towards a phenotype consistent with that of the nucleus pulposus will be assessed. We will test the hypothesis that the unique micro-environment of the intervertebral disc serves to enhance the differentiation of MSC to cells displaying a nucleus pulposus-like phenotype. 2. To isolate a notochordal population of cells from the nucleus pulposus; to examine the impact of these cells on the commitment of MSC to the nucleus pulposus phenotype. We will examine the impact of notochordal cells, isolated from the nucleus pulposus of the young rat, on the differentiation of MSC and the formation of a nucleus pulposus-like tissue. We will co-culture notochordal with the pre-differentiated MSC prior to their insertion into the nucleus pulposus cavity. We will test the hypothesis that cells of notochordal origin stimulate the expression of the nucleus pulposus phenotype. 3. To assess whether transplanted MSC can be used in vivo to repopulate the rat nucleus pulposus. Suspended in an injectable hydrogel, we will surgically transplant pre-differentiated MSC into the nucleus pulposus cavity of normal rat discs in vivo. We will evaluate the vitality of the cells and their creation of a nucleus pulposus-like tissue. Outcomes from this study will validate the in vitro studies performed in Specific Aims 1 and 2 and permit us to test the hypothesis that MSC could differentiate into nucleus pulposus-like cells in vivo. In the long term, if successful, this approach to therapy will entail using patients' own cells for disc regeneration.