Fig 2: Increased DNA double strand break repair in early-passage MSCs is ATM-dependent. Early- and late-passage MSCs without or with 2-hour KU55933 pretreatment (10 µM) were subjected to untreated (control) and treated with ?-irradiation at 8 Gy, followed by western blot analysis 2 hours later (A, B), colony formation assay 14 days later (C), measurement (D upper panel) and quantification of DNA damage (D lower panel) in olive tail moment (OTM) as the percentage of DNA in the tail (DNA% × tail moment length) 12 hours later (magnification: 200×). The results are representative of three independent experiments using MSCs from one individual. Data are presented as mean ± SD. ***, p < .001 (Wilcoxon signed rank test). Abbreviation: MSCs, mesenchymal stem cells.

Fig 3: MCELNs decreased the DNA damage of H9C2 cells after radiation. (A) Immunofluorescence staining of ?-H2A.X (green) in H9C2 cells after 48 h of culture with indicated treatment. The nucleus were stained with DAPI (blue), scale bar: 10 µm. Western blot images (B) and quantitation (C) of ?-H2A.X in H9C2 cells after 48 h of culture with indicated treatment. (D) Immunofluorescence staining of p-ATM (green) in H9C2 cells after 48 h of culture with indicated treatment. The nucleus were stained with DAPI (blue), scale bar: 10 µm. Western blot images (E) and quantitation (F) of p-ATM and ATM in H9C2 cells after 48 h of culture with indicated treatment. IR (–/+): 0/16 Gy X-ray; MCELNs (–/+): 0/10 µg/mL. All data were represented as means ± SD (n = 3 independent experiments). The statistical significance was evaluated by one-way ANOVA followed by the Turkey's multiple comparisons test among groups.

Fig 4: Inhibition of ATM and YAP1 reduces IL-18 secretion and ameliorates inflammation.a Immunoblots of intestinal enteroid lysate from G4 enteroids treated with or without ATM or YAP1 inhibitors for the indicated antibodies (n = 2). b qRT-PCR for the indicated genes with RNA from enteroids treated with DMSO only or inhibitors for ATM or YAP1 (n = 4). P values were calculated using two sided t test. The following are the p-values, pro-IL18, p = 0.0030, Nlrp1b, p = 0.0018, Nlrp6, p = 0.0015, Nlrc4, p = 0.0010. c Model representing the telomere dysfunction-mediated inflammasome pathway and the nodes at which the inhibitors for YAP1, caspase-1 or antibiotics inhibit the pathway leading to reduced secretion cleavage of caspase-1 and secretion of IL-18 by the colonic epithelium. d Hematoxylin and eosin staining of colon tissue from G4 mice treated with or without the YAP inhibitor, verteporfin. (control, n = 5; inhibitor treated, n = 6). Scale bars, 50 µm. e Histopathological score of the intestinal phenotype of the G4 mice treated with or without verteporfin (Yapi) (control, n = 5; inhibitor treated, n = 6). P values were calculated using two sided t test, p = 0.0048. f ELISA for the quantification of mature IL-18 from the colonic epithelium of the G4 mice treated with or without verteporfin (Yapi) (control, n = 5; inhibitor treated, n = 6).P values were calculated using two sided t test, p < 0.0001. g Western blot of colonic lysate from the colonic epithelium of the G4 mice treated with or without verteporfin (Yapi), for the indicated antibodies (n = 3). *statistically significant, p < 0.05 by unpaired Student’s t test, two-tailed. n represents number of mice used in the study. Data are represented as mean ± SEM. Experiments were conducted at least two independent times.