Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
J Clin Invest. 2012 Jul;122(7):2601-12. doi: 10.1172/JCI45785. Epub 2012 Jun 18.
The accumulation of cellular damage, including DNA damage, is thought to contribute to aging-related degenerative changes, but how damage drives aging is unknown. XFE progeroid syndrome is a disease of accelerated aging caused by a defect in DNA repair. NF-κB, a transcription factor activated by cellular damage and stress, has increased activity with aging and aging-related chronic diseases. To determine whether NF-κB drives aging in response to the accumulation of spontaneous, endogenous DNA damage, we measured the activation of NF-κB in WT and progeroid model mice. As both WT and progeroid mice aged, NF-κB was activated stochastically in a variety of cell types. Genetic depletion of one allele of the p65 subunit of NF-κB or treatment with a pharmacological inhibitor of the NF-κB-activating kinase, IKK, delayed the age-related symptoms and pathologies of progeroid mice. Additionally, inhibition of NF-κB reduced oxidative DNA damage and stress and delayed cellular senescence. These results indicate that the mechanism by which DNA damage drives aging is due in part to NF-κB activation. IKK/NF-κB inhibitors are sufficient to attenuate this damage and could provide clinical benefit for degenerative changes associated with accelerated aging disorders and normal aging.
细胞损伤的积累,包括 DNA 损伤,被认为是导致与衰老相关的退行性变化的原因,但损伤如何导致衰老尚不清楚。XFE 早衰综合征是一种由 DNA 修复缺陷引起的加速衰老疾病。NF-κB 是一种受细胞损伤和应激激活的转录因子,其活性随着衰老和与衰老相关的慢性疾病而增加。为了确定 NF-κB 是否会因自发的、内源性 DNA 损伤的积累而导致衰老,我们测量了 WT 和早衰模型小鼠中 NF-κB 的激活情况。随着 WT 和早衰小鼠的衰老,NF-κB 在各种细胞类型中随机激活。NF-κB 激活激酶 IKK 的 NF-κB 激活的 p65 亚基的一个等位基因的遗传缺失或用药理学抑制剂处理,延迟了早衰小鼠的与年龄相关的症状和病理。此外,抑制 NF-κB 减少了氧化 DNA 损伤和应激,并延迟了细胞衰老。这些结果表明,DNA 损伤导致衰老的机制部分归因于 NF-κB 的激活。IKK/NF-κB 抑制剂足以减轻这种损伤,并可为与加速衰老障碍和正常衰老相关的退行性变化提供临床益处。