NELF-A controls Drosophila healthspan by regulating heat-shock protein-mediated cellular protection and heterochromatin maintenance

Epigenetic alteration is a hallmark of aging, but it remains unclear if perturbation of transcription machineries may affect longevity. NELF-mediated pausing of RNA polymerase II (RNAPII) constitutes an important step in transcription regulation. We found that halving NELF-A level in heterozygous mutants or via neuronal-specific depletion of NELF-A improves locomotor activity, stress resistance and lifespan of Drosophila significantly. Mechanistically, lower NELF-A releases paused RNAPII to facilitate productive transcription of the heat-shock protein (Hsp) genes. Elevated HSPs attenuate the level of protein aggregation, reactive oxidative species, DNA damage and systemic inflammation in the brains of NELF-A depleted flies. This protection is conserved in human cells where NELF-A depletion confers improved resistance against oxidative stress. Reduced oxidative DNA damage allows the maintenance of H3K9me2-enriched heterochromatin, which represses the activation of specific retrotransposons during aging. Therefore, by regulating transcription of Hsp genes in the brains, NELF-A controls multiple aspects of aging in Drosophila.