STEM CELLS AND AGING

描述（由申请方提供）：将在早衰小鼠模型中检验骨髓干细胞是衰老决定因素的假设。首先，将在体外和体内测定来自野生型p53+/+和早衰p53+/m C57 BL/6 J小鼠的骨髓干细胞的数量和归巢能力。然后，将确定野生型骨髓干细胞纠正p53+/m突变小鼠中过早衰老的能力，以及来自过早衰老p53+/m突变小鼠的骨髓干细胞诱导野生型受体中过早衰老的能力。在特定目标1中，将通过流式细胞术和体外集落形成测定野生型p53+/+、p53+/-和p53+/m小鼠中的干细胞数量，并通过体外迁移和体内骨髓再增殖测定归巢。在特定目标2中，将来自GFP+雄性C57 BI 6 p53+/+小鼠的骨髓细胞移植到p53突变体（p53+/m）和野生型（p53 +/+）雌性小鼠中，并测定对衰老表型发展的影响。供体细胞对受体组织的贡献将通过GFP和Y染色体的存在来鉴定。如果衰老是由于骨髓干细胞在该模型中促进正常组织替代的能力降低，则将正常小鼠的骨髓细胞移植到p53突变小鼠应恢复正常表型和正常寿命。在Specific Aim 3中，将来自GFP+ p53+/m雄性突变小鼠的骨髓细胞移植到经辐照的正常野生型雌性小鼠和雌性突变小鼠中，以确定衰老表型是否可以转移突变骨髓干细胞。最后，将确定供体骨髓细胞与受体小鼠的组织细胞融合的可能性以及融合细胞在肿瘤中的存在。这些实验的结果应该为成体干细胞最重要的假设性质之一提供关键的证据。

DESCRIPTION (provided by applicant): The hypothesis that bone marrow stem cells are a determining factor in ageing will be tested in a mouse model of premature ageing. First, the number and homing capacity of bone marrow stem cells from wild type p53+/+ and premature ageing p53+/m C57BL/6J mice will be assayed in vitro and in vivo. Then, both the ability of wild-type bone marrow stem cells to correct premature ageing in p53+/m mutant mice, and the ability of bone marrow stem cells from premature ageing p53+/m mutant mice to induce premature ageing, in wild-type recipients will be determined. In Specific Aim 1, the number of stem cells in wild-type p53+/+, p53+/- and p53+/m mice will be determined by flow cytometry and by in vitro colony formation, and homing determined by in vitro migration and marrow repopulation in vivo. In Specific Aim 2 bone marrow cells from GFP+ male C57BI6 p53+/+ mice will be transplanted to p53 mutant (p53+/m) and to wild-type (p53 +/+) female mice and the effect on the development of the aging phenotype determined. The contribution of donor cells to recipient tissues will be identified by the presence of GFP and the Y-chromosome. If ageing is due to a decreased ability of bone marrow stem cells to contribute to replacement of normal tissues in this model, transplantation of bone marrow cells from normal mice to p53 mutant mice should restore normal phenotype and normal life span. In Specific Aim 3 bone marrow cells from GFP+ p53+/m male mutant mice will be transplanted to irradiated normal wild-type female mice and to female mutant mice to determine if the aging phenotype can be transferred mutant bone marrow stem cells. Finally the possibility of fusion of donor bone marrow cells with tissue cells of recipient mice and the presence of fused cells in tumors will be determined. The results of these experiments should provide critical proof for one of the most important hypothetical properties of adult stem cells.