Fig 2: YAP as a target for the treatment of PSC and its mechanism of action. BEC, biliary epithelial cells; CCA, cholangiocellular carcinoma; EMT, epithelial-mesenchymal transition; qHSC, quiescent hepatic stellate cells.

Fig 3: Verteporfin and metformin prevent the progression of biliary fibrosis in the Abcb4-/- model and downregulate the expression of YAP. (A) The extent of fibrotic areas in sirius red-stained slides was analyzed quantitatively and representative images were shown (D). (B. C) Immunohistochemistry was performed to evaluate the positive area of α-SMA and collagen 1α1 in the liver. Representative images and quantitative analysis were shown (E. F). Magnification, 5× (scale bar=200 µm) and 20× (scale bar=50 µm). The squares in dashed lines indicated the areas shown in 20-folds images. (G) Immunohistochemical staining of YAP was performed in the liver tissues and analyzed quantitatively in percentage (%) by whole slide scanning. (H-K) The mRNA expression as 2-∆∆Ct of YAP, CTGF, Integrin αV, and Integrin β6 under treatment was investigated in the liver. The values shown were normalized based on the mean of GAPDH and 36B4 in indicated control group. (L) Representative immunofluorescence co-staining of YAP/CK19 and CTGF/CK19 in control mice were shown. Magnification, 20× (scale bar=50 µm). VP, verteporfin; MF, metformin. Quantitative analysis of stained areas in percentage (%) was quantified by the QuPath software. n=4. *, P<0.05, **, P<0.01, ***, P<0.001, ANOVA; test of normality by Shapiro-Wilk (P>0.05). The results are shown as mean ± standard error of the mean.

Fig 4: a Treatment with selected inhibitors prevents nicotine-mediated induction of Sox2; the Src family kinases appear to be especially vital for the induction. b Depletion of Src, Yes or β-arrestin-1 reduces the nicotine-mediated induction of Sox2 in A549 cells (c) Treatment with a siRNA to Src reduces YAP1 levels and its interaction with E2F1; similar results were obtained upon treatment with a Src inhibitor (d). e Proximity ligation assay showing that depletion of Src abrogates the interaction of YAP1 with E2F1; similar results were obtained upon treatment with a Src inhibitor (f). g An IP-western blot experiment showed that depeltion of Yes and perhaps Src reduces the icotine-mediated interaction of YAP1 with E2F1

Fig 5: Effect of loss of YAP/TAZ on periodontal homeostasis. (A–E) Ultrathin ground sections stained with van Kossa’s stain as a mineralization marker. (A) is a control and (B–E) are from mutant mice at increasing levels of magnification. Alveolar bone (ab), root dentin (de), periodontal ligament (pdl), and cellular cementum (ccem) are labeled for orientation purposes. Note the partially mineralized cellular cementum (ccem) in the mutant mice. (E) illustrates incomplete mineralization of cellular cementocytes (ccem). (F,G) Mandibular tooth row comparison between wild type (F) and mutant (G) mice. The three mandibular molars (m1, m2, m3) are labeled. Note the lingual inclination of the third molar (m3) in YAP1/TAZ mutant mice (G). (H) Gene expression comparison for select mineralization related markers between wild type and Hippo mutant mice. Representative RT-qPCR for ALP, COL1A, OCN, RUNX2, YAP1, TRAP, IL-6, and cathepsin K transcript levels in mandibles from wild type and Hippo mutants. Transcript levels were normalized to β-actin levels and are presented as fold difference. As expected, YAP1 levels are down 70% in Hippo mutant samples. Representative data from n > 3. t test for statistical level of significance; *, p < 0.05; ***, p < 0.005, n.s, not significant. The bar in (A) is for (A–D). (E) is at a 10× higher magnification.