Fig. 7: YAP-1 is required for longevity and pressure-induced collagen expression during aging.

a Loss-of-function mutants of yap-1(tm1416) blunted longevity upon reduced Insulin/IGF-1 signaling. For raw data, additional trials, and statistics, see Supplementary Data 7. b, c YAP-1::GFP expression was increased upon reducing insulin/IGF-1 signaling. b Representative images show increased expression of ihIs35 YAP-1::GFP in animals fed with daf-2 RNAi as compared to L4440 control at 20°C and 25°C. Scale bar = 50 µm. c The graph shows the quantified data for the YAP-1::GFP expression. Individual dots represent the number of animals. Data are represented as columns with mean + SEM. n = 3 independent biological trials. Welch’s t-test, two-tailed was used for significance analysis for the P value. For raw data and statistical details, see Supplementary Data 13. d, e YAP-1::GFP expression localizes at hemidesmosome-containing structures was increased upon reducing insulin/IGF-1 signaling at 25°C. d Representative images show increased expression of ihIs35 YAP-1::GFP in animals fed with daf-2 RNAi as compared to L4440 control at 25°C. Scale bar = 10 µm. e The graph shows the distribution of the categories of hemidesmosome-containing structures. Individual dots represent the number of animals. Data are represented as columns with mean + SEM. n = 3 independent biological trials. Welch’s t-test, two-tailed was used for significance analysis for the P value. For raw data and statistical details, see Supplementary Data 13. f, g Upon daf-2(RNAi) at 25°C, more YAP-1 was colocalized with VAB-10. The boxed areas are enlarged on the right showing the ihIs35 YAP-1::GFP (green channel), mc100 VAB-10A::mCherry (red channel), and merge of the confocal images using the transgenic strain LSD2207. Scale bar = 10 µm. Representative images of one independent biological trial. For additional images and individuals, see Supplementary Data 13. h Schematic of YAP-1 localizing at the hemidesmosome-containing structure between the apical and basal VAB-10 based on confocal images shown in (g). Not drawn to scale. i YAP-1::GFP expression was increased upon constant pressure for three days at 25°C. Individual dots represent the number of animals. Data are represented as columns with mean + SEM. n = 3 independent biological trials. Welch’s t-test, two-tailed was used for significance analysis for the P value. For raw data and statistical details, see Supplementary Data 13. j, k Pressure induces collagen expression in the hypodermis. j Representative images of LSD1126 Pcol-120::mNeonGreen; Pmyo-3::mCherry transgenic C. elegans either kept under 12 Pa pressure for 72 h starting at L4 at 20°C or not. Scale bar = 50 µm. k Quantification of 3 independent biological trials (n=3). An unpaired t-test, two-tailed was used for significance analysis for the P value. For raw data and statistical details, see Supplementary Data 14. (l) Promoter-driven col-144::GFP expression in a temperature-sterile background (LSD2002) was increased upon constant 12 Pa pressure for three days at 25°C. Individual dots represent the number of animals. Data are represented as columns with mean + SEM. n = 5 independent biological trials. Welch’s t-test, two-tailed was used for significance analysis for the P value. For raw data, additional trials also at 20°C, and statistical details, see Supplementary Data 14. (m) Mutations in unc-52(e669,su250) blunted promoter-driven col-144::GFP expression upon constant 12 Pa pressure for three days at 25°C. Individual dots represent the number of animals. Data are represented as columns with mean + SEM. n = 5 independent biological trials. One-way ANOVA was used for significance analysis for the P value. For data and statistical details, see Supplementary Data 14. n Knockdown of yap-1 abolished the promoter-driven col-144::GFP expression upon constant 12 Pa pressure for three days at 25°C. 1 independent biological trial is shown. One-way ANOVA was used for significance analysis. For data, additional trials, and statistical details, see Supplementary Data 14. o Proposed biomechanical model of ECM homeostasis and longevity. The right model is adapted for our C. elegans finding from the mechanobiological regulation of arterial walls, which include smooth muscles, endothelial cells, fibroblasts, and ECM (by Humphrey and Schwartz 2021)⁶³. The left model depicts the ECM homeostasis-related process that declines during aging but is counteracted by longevity interventions.