Enhancing the potency of aged adult stem cells for tissue reconstruction

摘要 每年有50多万名患者接受手术修复巨大的骨缺陷。 然而，目前可用于骨重建的两种主要选择是使用骨 从受伤的患者身上通过额外的手术或骨移植获得 身体捐赠者。然而，这些多重手术给患者带来了严重的并发症。因此， 骨工程为再生医学提供了一种有吸引力的替代方法。间充质 干细胞(MSCs)在工程化骨移植方面具有巨大的潜力，并已被证明是 在三维(3D)支架中体外生成骨细胞。然而，治疗应用 人骨髓间充质干细胞在骨再生和重建中的作用仍然受到生理性衰老的限制 分化潜力的相关下降，损害了其可行性和重复性 治疗。此外，由MSCs产生的骨移植仅有几毫米大小，限制了它们的使用 在临床环境中。端粒缩短限制细胞增殖，最终导致体外培养 衰老和功能丧失。我们设计了一种高度创新的方法，以克服这些 挑战基于我们实验室的初步数据表明， ZSCAN4因子可以修复老化的MSCs。我们的总体目标是设计新的协议 产生适合于治疗退行性骨病和骨的骨移植 整形手术。在这项应用中，我们将a.建立临床规模的骨移植从 扁桃体来源的人MSCs。确定ZSCAN4对老年人骨分化潜能的影响 并将体外老化的MSCs作为一种手段，使其可伸缩到人骨大小的要求。c. 确定ZSCAN4在茎势调节中的作用。

ABSTRACT More than half a million patients undergo surgeries to repair of large bony defects every year. However, the two primary options currently available for bone reconstruction are the use of bone harvested from the patient suffering from the injury by additional surgeries, or bone grafts from cadaver donors. However, these multiple operations incur significant morbidity on the patient. Thus, bone engineering offers an attractive alternative approach for regenerative medicine. Mesenchymal stem cells (MSCs) have a great potential for engineering bone grafts and have been shown to generate bone cells in-vitro in three dimensional (3D) scaffolds. However, the therapeutic application of human MSCs in bone regeneration and reconstruction is still limited by a physiological aging related decline in their differentiation potential, compromising the feasibility and reproducibility of therapies. Moreover, bone grafts generated from MSCs are only millimeters in size limiting their use in a clinical setting. Telomere shortening restricts cell proliferation and ultimately leads to in-vitro aging and loss of function. We have designed a highly innovative approach, to overcome these challenges based on preliminary data from our laboratory showing that the differentiation potency of aged MSCs can be restored by the factor ZSCAN4. Our overall goal is to design novel protocols generate bone grafts suitable for the treatment of degenerative bone diseases and bone reconstructive surgeries. In this application we will a. Establish a clinically scaled bone graft from tonsil derived human MSCs. b. Define the effects of ZSCAN4 on bone differentiation potential of aged and in vitro aged MSCs as a mean to allow the scalability to human bone size requirements. c. Determine the role of ZSCAN4 in regulation of stemness potency.