Inhibition of retrotransposition improves health and extends lifespan of SIRT6 knockout mice
Mice deficient for SIRT6 exhibit a severely shortened lifespan, growth retardation, and highly elevated LINE1 (L1) activity. Here we report that SIRT6 deficient cells and tissues accumulate abundant cytoplasmic L1 cDNA which triggers massive type I interferon response via activation of cGAS. Remarkably, nucleoside reverse transcriptase inhibitors (NRTIs), which inhibit L1 retrotransposition, significantly improved health and lifespan of SIRT6 knockout mice and completely rescued type I interferon response. In tissue culture, inhibition of L1 with siRNA or NRTIs abrogated type I interferon response, in addition to a significant reduction of DNA damage markers. These results indicate that L1 activation contributes to the pathologies of SIRT6 knockout mice. Similarly, L1 transcription, cytoplasmic cDNA copy number and type I interferons were elevated in the wild type aged mice. As sterile inflammation is a hallmark of aging we propose that modulating L1 activity may be an important strategy for attenuating age-related pathologies.\n\nHighlightsO_LISIRT6 KO mice accumulate L1 cDNA triggering type I interferon response via cGAS pathway\nC_LIO_LIWild type aged mice accumulate L1 cDNA and display type I interferon response\nC_LIO_LIReverse transcriptase inhibitors rescue type I interferon response and DNA damage\nC_LIO_LIReverse transcriptase inhibitors extend lifespan and improve health of SIRT6 KO mice\nC_LI