DNA damage and repair in old and young and in participants in the BLSA

双链断裂是DNA中非常危险的损伤，必须修复才能让细胞完成复制和转录。具有双链断裂修复缺陷的细胞受到基因组不稳定性的影响，并且具有这些缺陷的个体通常具有较高的癌症风险。双链断裂的存在可以通过检查细胞中被称为H2 AX的组蛋白变体的磷酸化形式来确定。蛋白质的磷酸化在双链断裂附近迅速发生，并持续到断裂修复。因此，磷酸-H2 AX可作为断裂的替代标记物。这种物质可以通过免疫荧光技术容易地检测到，因此可以在单细胞中检测到。我们正在测试的假设，双链断裂是在来自老年人的细胞中，与年轻人相比，在升高的水平，通过确定磷酸-H2 AX在血液来源的细胞从供体在BLSA程序。结果表明，来自老年人的细胞比来自年轻人的细胞含有更频繁的H2 Ax位点。 我们还通过凝胶电泳分析在单细胞水平上测量DNA修复的频率。

Double strand breaks are very dangerous lesions in DNA and must be repaired to allow cells to complete replication and transcription. Cells with deficiencies in double strand break repair are subject to genomic instability and individuals with these deficiencies are often at elevated risk of cancer. The presence of double strand breaks can be determined by examining cells for the phosphorylated form of a histone protein variant known as H2AX. Phosphorylation of the protein occurs rapidly in the vicinity of a double strand break, and persists until the break is repaired. Consequently phospho-H2AX serves a surrogate marker for breaks. This species can be easily detected by immunofluorescence techniques, and thus can be detected in single cells. We are testing the hypothesis that double strand breaks are presented in elevated levels in cells from aged individuals, as compared with younger individuals, by determining the level of phospho-H2AX in blood derived cells from donors in the BLSA program. The results indicate that cells from older individuals contain more frequent H2Ax sites than cells fromyounger individuals. The frequency We are also measuring DNA repair at the single cell level by gel electrophoresis assays.