FUdR effects on proteostasis during development are independent of GSC inhibition.

<p>(A) Age-synchronized <i>glp-1(e2141)</i> animals raised in the absence (black) or presence (gray) of FUdR were exposed to a 37°C HS for 6 h on the first day of adulthood and survival was assayed. Data represent means ± SEM of >5 independent experiments. <i>P</i> values compare age-matched treated and untreated animals. (*) <i>P</i><0.05 and (**) <i>P</i><0.01. (B) The motility of age-synchronized <i>unc-54(e1301);glp-1(e2141)</i> animals raised in the absence (black) or presence (gray) of FUdR was examined on the first and second days of adulthood and the percent of paralyzed animals was scored. Data represent means ± SEM of >3 independent experiments. <i>P</i> values compare age-matched treated and untreated animals. (*) <i>P</i><0.05 and (**) <i>P</i><0.01.</p

Animals raised on FUdR maintain the ability to mount a protective stress response during adulthood.

<p>(A) Age-synchronized wild type (wt) animals raised in the absence (black) or presence (gray) of FUdR were exposed to a 37°C HS for 6 h and survival was assayed. Data represent means ± SEM of >4 independent experiments. <i>P</i> values compare age-matched treated and untreated animals. (*) <i>P</i><0.05 and (**) <i>P</i><0.01. (B) Images of age-synchronized wild type animals expressing GFP under control of the <i>hsp-16.2</i> promoter (<i>phsp-16.2::GFP</i>) raised in the absence or presence of FUdR and subjected to a short HS (90 min at 37°C) on the first or second day of adulthood. Scale bar is 250 µm. (C) Quantification of <i>hsp-70</i> (left) and <i>hsp-16.11</i> (right) mRNA levels from age-synchronized wild type animals raised in the absence (black) or presence (gray) of FUdR and challenged with a short HS (90 min at 37°C) on the first or second day of adulthood. The data presented are normalized to day 1 of adulthood HS treated animals. Data represent means ± SEM of >3 independent biological samples. <i>P</i> values compare mRNA levels on the second day of adulthood with same-treated animals on day 1 of adulthood. (*) <i>P</i><0.05 and (**) <i>P</i><0.01.</p

FUdR treatment improved proteostasis before the onset of reproduction.

<p>(A–B) The motility of age-synchronized temperature-sensitive <i>unc-45(e286)</i> (A), or <i>unc-54(e1301)</i> (B) animals raised in the absence (black) or presence (gray) of FUdR was examined on the first and second days of adulthood and the percent of paralyzed animals was scored. Data represent means ± SEM of 5 independent experiments. <i>P</i> values compare age-matched treated and untreated animals. (**) <i>P</i><0.01. (C) Confocal images of age-synchronized <i>unc-54(e1301)</i> animals raised in the absence or presence of FUdR, and stained with anti-UNC-54 antibodies (green) and Phalloidin (red). Arrows indicate myofilaments. Scale bar is 10 µm.</p

FUdR treatment improved proteostasis after the onset of reproduction.

<p>(A) Age-synchronized <i>dyn-1(ky51)</i> animals raised in the absence (black) or presence (gray) of FUdR were shifted to 28°C on the first or second days of adulthood and the percent of coiled animals was scored. Data represent means ± SEM of 4 independent experiments. <i>P</i> values compare age-matched treated and untreated animals. (*) <i>P</i><0.05. (B) The motility of age-synchronized temperature-sensitive <i>unc-52(e669su250)</i> animals raised in the absence (black) or presence (gray) of FUdR was examined on the first and second days of adulthood and the percent of paralyzed animals was scored. Data represent means ± SEM of 5 independent experiments. <i>P</i> values compare age-matched treated and untreated animals. (*) <i>P</i><0.05 and (**) <i>P</i><0.01. (C) Confocal images of age-synchronized <i>unc-52(e669su250)</i> animals raised in the absence or presence of FUdR, and stained with anti-MYO-3 antibodies (green) and phalloidin (red). Arrows indicate myofilaments. Scale bar is 10 µm.</p

Fluorodeoxyuridine Improves <i>Caenorhabditis elegans</i> Proteostasis Independent of Reproduction Onset

<div><p>Protein homeostasis (proteostasis) networks are dynamic throughout the lifespan of an organism. During <i>Caenorhabditis elegans</i> adulthood, the maintenance of metastable proteins and the activation of stress responses are inversely associated with germline stem cell proliferation. Here, we employed the thymidylate synthase inhibitor 5-fluoro-2′-deoxyuridine (FUdR) to chemically inhibit reproduction, thus allowing for examination of the interplay between reproduction and somatic proteostasis. We found that treatment with FUdR modulates proteostasis decline both before and after reproduction onset, such that effective induction of the heat shock response was maintained during adulthood and that metastable temperature-sensitive mutant phenotypes were rescued under restrictive conditions. However, FUdR treatment also improved the folding capacity of germline- and gonadogenesis-defective mutants, suggesting that proteostasis modulation by FUdR is independent of germline stem cell proliferation or inhibition of reproduction. Our data, therefore, indicate that FUdR converges on alternative regulatory signals that modulate <i>C. elegans</i> proteostasis capacity during development and adulthood.</p></div