1. Senescence suppresses the integrated stress response and activates a stress-remodeled secretory phenotype.
- Author
-
Payea, Matthew J., Dar, Showkat A., Anerillas, Carlos, Martindale, Jennifer L., Belair, Cedric, Munk, Rachel, Malla, Sulochan, Fan, Jinshui, Piao, Yulan, Yang, Xiaoling, Rehman, Abid, Banskota, Nirad, Abdelmohsen, Kotb, Gorospe, Myriam, and Maragkakis, Manolis
- Subjects
- *
TRANSCRIPTION factors , *GENE expression , *GENETIC translation , *RNA sequencing , *AGING - Abstract
Senescence is a state of indefinite cell-cycle arrest associated with aging, cancer, and age-related diseases. Here, we find that translational deregulation, together with a corresponding maladaptive integrated stress response (ISR), is a hallmark of senescence that desensitizes senescent cells to stress. We present evidence that senescent cells maintain high levels of eIF2α phosphorylation, typical of ISR activation, but translationally repress production of the stress response activating transcription factor 4 (ATF4) by ineffective bypass of the inhibitory upstream open reading frames (uORFs). Surprisingly, ATF4 translation remains inhibited even after acute proteotoxic and amino acid starvation stressors, resulting in a highly diminished stress response. We also find that stress augments the senescence-associated secretory phenotype with sustained remodeling of inflammatory factors expression that is suppressed by non-uORF carrying ATF4 mRNA expression. Our results thus show that senescent cells possess a unique response to stress, which entails an increase in their inflammatory profile. [Display omitted] • Senescent cells have basal levels of eIF2α phosphorylation without ATF4 expression • Senescence is accompanied by a global decrease in ribosome content • Reduced ribosome content suppresses the ability of stress to activate the ISR • Acute stress modulates the SASP up to days after the stress has been removed Payea et al. find that ribosome depletion associated with senescence suppresses the integrated stress response (ISR) and leads to transcriptional remodeling of the senescence secretome. Stress-induced secretory remodeling (SSR) lasts days after the initial stress is removed and is suppressed by reactivation of the ISR. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF