Figure 5. The ryanodine receptor (RyR)-stabilizing drug S107 increases body wall muscle calcium (Ca²⁺) transients in aged Caenorhabditis elegans; (A) UNC-68 was immunoprecipitated and immunoblotted with anti-RyR, anti-calstabin, and dinitrophenyl (DNP; marker of oxidation) in aged nematodes (Day L4, 5, and 15) with 10 µM of S107 (5 hr).

(B–C) Quantification of the band intensity shown in (A): band intensity was defined as the ratio of either DNP (marker of UNC-68 oxidation) or FKB-2 binding over its corresponding /UNC-68 expression. Data are mean ± SEM. * p<0.05 vs. wild-typd L4 (WTL4), # p<0.05 WT D15 vs. WT D15 + S107. (D–E) Contraction-associated Ca²⁺ transients were measured in age-synchronized WT (day 3 and 15) (D) and (E) FKB-2 KO worms (day 3 and 7). Contraction-associated Ca²⁺ transients in S107-treated worms were performed at day 15 for WT and day 7 for FKB-2 worms. (F) Graph showing number of bends recorded for WT vs. WT treated with S107 worms at different ages (day 3, 7, and 15). (G) Percent of survival of WT vs. WT treated with S107 nematodes; Gehan-Breslow-Wilcoxon test for survival comparison was performed for statistical significance. (H) UNC-68 was immunoprecipitated and immunoblotted with anti-RyR, anti-calstabin, and DNP (marker of oxidation) in short-lived nematodes (MEV-1) with S107 treatment (5 hr). (I–J) Quantification of the band intensity shown in (H): band intensity was defined as the ratio of either DNP (marker of UNC-68 oxidation) or FKB-2 binding over its corresponding /UNC-68 expression. N ≥ 20 per group. Data are mean ± SEM from triplicate experiments. One-way ANOVA shows * p < 0.05 vs WT L4 unless otherwise indicated. In panel F, a t-test was used to compare WT and WT + S107 for each day. #p<0.05 MEV-1, vs. MEV-1 +S107 in panel J. Figure 5—source data 1.