Radiation Damage Repair in the Brain via Human ES cells

描述(申请人提供)：脑照射是治疗癌症的有力工具，包括原发和转移的许多肿瘤，甚至白血病和淋巴瘤。然而，神经组织的耐受性差以及长期存活者会出现严重的副作用，限制了它的使用。其中包括智商和认知功能的下降。这种现象非常频繁，而且是不可逆转的。其发病机制尚未完全阐明，但它涉及广泛的脱髓鞘，以延迟的方式发生(几个月到几年)。根据在大鼠身上获得的初步数据，我们假设辐射耗尽了分裂的少突胶质细胞祖细胞(OPC)池，从而使大脑取代髓鞘细胞的能力。我们在人类ES(HES)细胞的神经分化方面积累了丰富的经验，我们建议将HES来源的神经前体移植作为修复辐射诱导的脑损伤的有效策略。 我们将在一年中的五个时间点研究大鼠全脑照射后细胞丢失的时间和地形图模式。大鼠将在牺牲前接受BrdU，大脑将被处理为BrdU、NG2(一种OPC标记)和其他神经标记。然后，我们将从HES细胞中获得两组不同的神经前体细胞移植到受照射的大鼠身上：多潜能神经干细胞样细胞群体和少突胶质前体细胞群体。在我们的初步数据中，我们已经成功地从HES细胞中分离出了这样的细胞，并通过慢病毒基因转移建立了稳定表达EGFP的HES细胞，用于可靠的体外和体内鉴定。移植动物将在移植后6周接受检查，以评估细胞存活、迁移和替代OPC利基的能力，并在移植后6-8个月评估HES细胞对损伤脑重新髓鞘形成的贡献。这项工作解决了脑癌治疗中的一个重要的治疗问题，并将提供大量关于移植的人类ES细胞在受损大脑背景下的行为的信息。如果成功，我们计划启动未来的研究，解决HES来源的神经前体移植对辐射诱导的认知能力下降的功能影响。这项资助将只使用INIH批准的细胞系：Hi。美国国立卫生研究院代码WA01。

DESCRIPTION (provided by applicant): Brain irradiation is a powerful tool in the treatment of cancers including primary and metastatic many tumors, and even leukemias and lymphomas. However its use is restricted by the poor tolerance of the nervous tissue and the development of serious side effects among long-term survivors. These include a decline in IQ and cognitive function. This phenomenon is very frequent and irreversible. Its pathogenesis is not fully elucidated but it involves extensive demyelination occurring in a delayed fashion (months to years). Based on preliminary data obtained in the rat, we hypothesize that radiation exhausts the pool of dividing oligodendrocyte progenitors (OPC) and therefore the brain's ability to replace the myelinating cells. We have developed significant experience in the neural differentiation of human ES (hES) cells and we propose the transplantation of hES-derived neural precursors as an effective strategy for repair of radiation-induced brain damage. We will study the temporal and topographic pattern of cell loss following whole brain irradiation in the rat at five timepoints over the course of one year. The rats will receive BrdU prior to sacrifice and the brains will be processed for BrdU, NG2 (an OPC marker) and other neural markers. We will then graft irradiated rats with two different populations of neural precursors obtained from hES cells: a multipotential neural stem cell-like population, and an oligodendroglial progenitor population. In our preliminary data we have successfully derived such cells from hES cells and established stable eGFP-expressing hES cells via lentiviral gene transfer for reliable in vitro and in vivo identification. Grafted animals will be examined at 6 weeks after transplantation to assess cell survival, migration, and ability to replace the OPC niche, and at 6-8 months after transplantation to evaluate the ability of hES cells to contribute to remyelination of the injured brain. This work addresses a therapeutically important problem in brain cancer treatment and will provide a wealth of information on the behavior of grafted human ES cells within the context of an injured brain. If successful, we plan to initiate future studies addressing the functional impact of hES-derived neural precursor grafts on radiation-induced cognitive decline. This grant will only use the INIH-approved cell line: HI. NIH code WA01.