干细胞的衰老学说

Aging of stem cells

文章从造血干细胞的自我更新和分化的过程中,阐明干细胞质和量的衰老,端粒缩减、氧化应激均加速干细胞的衰老,组蛋白的编码和转录子的激活可导致DNA或蛋白质的损伤。在干细胞衰老中,异染色质结构和基因转录的异常是干细胞衰老的重要调节机制。如果干细胞的衰老不是发生在基因水平上,那么则是发生在转录水平之中。因此在干细胞的造血中,众多的转录错误导致细胞周期衰老,是异染色质扩展的恶果。在正常的情况下,上述机制通常是不会发生的。如果仅仅是异染色质的错位,则不是干细胞基因表达的结果,在干细胞自我更新中充分证明,异染色质的改变导致了组蛋白的改变。

In this paper, the aging of the stem cells has been elucidated in the aspect of quantitative and qualitative exhaustion, such as balance self-renewal and differentiation of hematopoietic stem cells. The reduced telomere and oxidative stress both accelerate the aging course, besides, histone code and transcriptional activation lead to the DNA or protein damage. It plays an important role in the stem cell aging that the modulation of allochromosome structure and epigenetic regulation of gene transcription. If the aging of the stem cells doesn＇t happen on the level of the gene, it must result from the transcription. During the haemopoiesis process of stem cells, all kinds of the transcriptional mistakes will lead to the aging of cell cycle, which is the result of allochromosome enlarging. However, the above mechanism will not occur normally. Only allochromosome allotopia is not explainable to the gene expression of stem cells. The proof of stem cells＇ self-renewal evidences that if not the consequence of cell expression, allochromosome change the histone.