Opposing p53 and mTOR/AKT promote an in vivo switch from apoptosis to senescence upon telomere shortening in zebrafish

eLife

Marta Marzullo¹  Mounir El Maï²  Inês Pimenta de Castro³  Miguel Godinho Ferreira³ 

[1]Instituto Gulbenkian de Ciência, Oeiras, Portugal

[2]Institute for Research on Cancer and Aging of Nice (IRCAN), Université Côte d’Azur, Nice, France

[3]Instituto Gulbenkian de Ciência, Oeiras, Portugal

关键词: telomeres;    apoptosis;    senescence;    p53;    AKT;    aging;   

DOI  :  10.7554/eLife.54935

来源: DOAJ

【 摘 要 】

Progressive telomere shortening during lifespan is associated with restriction of cell proliferation, genome instability and aging. Apoptosis and senescence are the two major outcomes upon irreversible cellular damage. Here, we show a transition of these two cell fates during aging of telomerase deficient zebrafish. In young telomerase mutants, proliferative tissues exhibit DNA damage and p53-dependent apoptosis, but no senescence. However, these tissues in older animals display loss of cellularity and senescence becomes predominant. Tissue alterations are accompanied by a pro-proliferative stimulus mediated by AKT signaling. Upon AKT activation, FoxO transcription factors are phosphorylated and translocated out of the nucleus. This results in reduced SOD2 expression causing an increase of ROS and mitochondrial dysfunction. These alterations induce p15/16 growth arrest and senescence. We propose that, upon telomere shortening, early apoptosis leads to cell depletion and insufficient compensatory proliferation. Following tissue damage, the mTOR/AKT is activated causing mitochondrial dysfunction and p15/16-dependent senescence.

【 授权许可】

Unknown