FUdR extends the lifespan of the short-lived AP endonuclease mutant in <i>Caenorhabditis elegans</i> in a fertility-dependent manner

Abstract

The anticancer drug 5-fluorouracil (5-FU) and its metabolite 5-fluoro-2′-deoxyuridine (FUdR) inhibit thymidylate synthase and induce uracil bases in DNA. FUdR is commonly used for inhibiting fertility when measuring the lifespan of the nematode Caenorhabditis elegans. However, it is not known whether DNA damage induced by FUdR affects lifespan. EXO-3 is an apurinic/apyrimidinic endonuclease in C. elegans, and we reported previously that deletion of the exo-3 gene causes reproductive abnormalities and decreased lifespan. In this study, we found that FUdR extended the lifespan of exo-3 mutants. We measured the lifespan of multiple germline mutants to examine whether this lifespan extension effect was dependent on fertility. In the presence of a fem-1 mutation, which causes a deficiency in sperm production, FUdR did not extend the lifespan of the exo-3 mutant. In glp-1 mutants, which do not develop gonads, the exo-3 mutant was not short-lived, and FUdR did not extend its lifespan. These results suggest that the lifespan extension effect of FUdR depends on fertility and the presence of gonads. fem-3 mutants, which do not produce oocytes, had increased lifespan in the presence of FUdR, independent of the exo-3 mutation. It is possible that the fem-3 mutant was susceptible to the lifespan extension effect of FUdR. From these results, we suggest that FUdR affects the lifespan of C. elegans in two ways: by interfering with fertility, which extends lifespan, and by inducing DNA base damage, which reduces lifespan.

Reactivation of RNA metabolism underlies somatic restoration after adult reproductive diapause in C. elegans

“…Finally, our work may shed light on the molecular mechanism of action of FUDR and, in particular, the inconsistent effects of FUDR on C. elegans lifespan and healthspan, as reported by a growing number of studies ( Van Raamsdonk and Hekimi, 2011 ; Aitlhadj and Stürzenbaum, 2010 ; García-González et al, 2017 ; Kato et al, 2017 ; Anderson et al, 2016 ; Angeli et al, 2013 ). It has been assumed that these effects were the result of FUDR inhibiting DNA synthesis and reproduction, but our results point to a potentially important role for inhibition of RNA metabolism, including maturation of rRNA.…”

“…Instead, recovery of somatic tissues involves nucleolar reactivation and a large expansion of the RNA pool, both of which are sensitive to FUDR. These findings provide insight into a key early steps in post-ARD somatic restoration, and allow better understanding of the pleiotropic effects of FUDR, including effects on longevity, that have been observed by many laboratories in recent years ( Van Raamsdonk and Hekimi, 2011 ; Aitlhadj and Stürzenbaum, 2010 ; García-González et al, 2017 ; Kato et al, 2017 ; Anderson et al, 2016 ; Angeli et al, 2013 ).…”

Juniperonic Acid Biosynthesis is Essential in Caenorhabditis elegans Lacking Δ6 Desaturase (fat-3) and Generates New ω-3 Endocannabinoids

“…We used FUdR to inhibit the progeny. FUdR supplementation has been known to cause a lifespan extension in a dose dependent manner in N2 (WT) animals and also in some short-lived mutants with altered metabolic patterns [54][55][56][57]. This discrepancy is noteworthy and needs to be explored in future studies.…”

ATG-18 and EPG-6 are Both Required for Autophagy but Differentially Contribute to Lifespan Control in Caenorhabditis elegans

“…Fluorodeoxyuridine (FUDR) is a thymidylate synthase inhibitor, which inhibits DNA synthesis in developing embryos. In early publications, it was reported that FUDR allows synchronization without interfering with the lifespan of C. elegans [36]; however, recent publications suggest that FUDR can prolong the lifespan of both wild-type and certain mutant animals [37,38,39]. Our experiments support this observation, as FUDR-treated wild-type animals indeed showed extended lifespan compared to untreated animals (Figure 8) and we also observed lifespan extension of epg-6 mutants upon FUDR treatment.…”

“…It also bears mentioning that germline ablation increases the lifespan of C. elegans in a DAF-2/DAF-16 dependent manner [43], and increased lifespan upon FUDR treatment was reported for FEM-3, a protein involved in oogenesis [38]. As the lifespan extension of the epg-6 mutant animals was observed under FUDR treatment conditions, it is tempting to speculate that the autophagy-independent function of EPG-6 could likely be found in the germline, as this is a prominent pathway affected by FUDR treatment.…”