题为“Somatic mutations impose an entropic upper bound on human lifespan”(https://www.biorxiv.org/content/10.1101/2025.11.23.689982v1)预印本的提出的一个寿命模型:增殖组织(如肝脏和皮肤)理论上可以存活数千年,因为它们会不断替换受损细胞。但这些不分裂的细胞最终会积累过多的不可逆 DNA 突变,成为衰老 ...
在个体中,由于功能性细胞会不断损耗掉,并由成体干细通过反复的复制和分化来补充。由于成体干细胞复制次数是有限的,因此,导致个体衰老的根本原因,归根结底还是成体干细胞的复制性衰老。 那么,成体干细胞为什么会发生复制性衰老?为此,科学家提出了五花八门的理论,但在“Telomere DNA and ribosomal DNA co-regula ...
In 1961, Leonard Hayflick and Paul Moorhead collaborated on culturing human embryonic fibroblasts and observed that these cells could only divide approximately 40 to 60 times in vitro before ceasing proliferation and entering a state of senescence. This phenomenon later became known as the Hayfl ...
作者:黄必录 细胞衰老的端粒DNA和核糖体DNA共调控假说(Telomere DNA and ribosomal DNA co-regulation model for cell senescence)认为,细胞衰老是由端粒和/或rDNA的阵列缩短通过P53介导的。 问:你怎么解释大象拥有比大多数哺乳动物多得多的 p53 拷贝,并且老化速度比它们慢得多这一事实? 答:衰老与p53基因 ...