Exploring the role of YAP1 and TAZ in pancreatic acinar cells and the therapeutic potential of VT-104 in pancreatic inflammation

Abstract

Background: Increasing evidence has linked the Hippo pathway with the fibroinflammatory diseases. However, the detailed roles of key hippo components in pancreatic inflammatory diseases still remain unclear.

Methods: A series of genetic knockout mice were generated targeting the key components of Hippo pathway to examine the individual effects of YAP1 and TAZ on pancreatic inflammation. Hematoxylin and eosin (H&E) staining, immunohistochemistry, and immunofluorescence staining were performed to evaluate the pancreas tissue from mice with various genotypes. The therapeutic potential of a recently developed YAP1/TAZ inhibitor VT-104 was also evaluated in our mouse model.

Results: Mice with acinar-specific knockout of YAP1/TAZ did not exhibit any histological abnormalities in the pancreas. LATS1/2 deficiency induced acinar to ductal metaplasia, immune cell infiltration, and fibroblast activation, which were rescued by the homozygous knockout YAP1, but not TAZ. Additionally, treatment with VT-104 also decreased pathological alterations induced by deletions of LATS1 and LATS2 in acinar cells.

Conclusion: Our findings highlight the critical role of YAP1 in modulating pancreatic inflammation and demonstrate that VT-104 holds therapeutic potential to mitigate pancreatitis-associated pathological manifestations. Further exploration is necessary to unravel the underlying mechanisms and translate these insights into clinical applications.

Keywords: Fibrosis; Hippo pathway; Inflammation; Pancreatitis; TAP1/TAZ.

Figure 1.

Acinar-specific knockout of YAP1 and TAZ did not disturb pancreas homeostasis under normal conditions. (A) The schema of experimental procedure. (B) The representative H&E staining images of the pancreas collected from the mice treated as indicated. H&E = hematoxylin and eosin, PTY = Ptf1a^CRE-ERYap1^fl/fl Taz^fl/fl Rosa26^LSL-YFP mice, TAM = tamoxifen.

Figure 2.

The pancreatic inflammation and damage caused by acinar-specific LATS1/2 knockout were not mitigated by the haplotype of YAP1 and TAZ. (A) The representative H&E staining images of the pancreas collected from the mice treated as indicated. (B) The representative IF images of F4/80 and α-SMA in the pancreas collected from PL and PLT^HertY^Hert mice 7 d after final TAM administration. (C) The representative IHC images of Ki67 in the pancreas collected from PL and PLY mice 7 d after final TAM administration. (D) The representative IF images of amylase and CK19 in the pancreas collected from PL and PLT^HertY^Hert mice 7 d after final TAM administration. PL mice (n = 5) and PLT^HertY^Hert mice (n = 7). CK19 = cytokeratin 19, H&E = hematoxylin and eosin, IF = immunofluorescence, IHC = Immunohistochemistry, LATS1/2 = large tumor suppressor 1/2, PL = Ptf1a^CRE-ER Lats1^fl/fl Lats2^fl/fl Rosa26^LSL-YFP mice, PLY = Ptf1a^CreER Lats1^fl/fl Lats2^{fl/f l}Yap1^fl/fl Rosa26^LSL-YFP mice, SMA = smooth muscle actin, TAM = tamoxifen.

Figure 3.

YAP1 is the essential mediator of the pancreatic inflammation and damages induced by LATS1/2 inactivation in acinar cells. (A) The representative H&E staining images of the pancreas collected from PL (n = 3) and PLY mice (n = 6) 7 d after final TAM administration. (B) The representative IHC images of YAP1, TAZ, and SPP1 in the pancreas collected from PL (n = 3) and PLY mice (n = 6) 7 d after final TAM administration. (C) The representative IF images of F4/80 and α-SMA in the pancreas collected from PL and PLY mice 7 d after final TAM administration. Average positive fluorescent area (in squared microns) of F4/80+ macrophage in PL mice (n = 3) was 12,624 ± 1512 while PLY mice (n = 3) was 2643 ± 1330 with P value = .001. The average positive fluorescent area of α-SMA for PL mice was 31,576 ± 7961 and PLY mice was 4860 ± 4315 with P value = .007. (D) The representative IHC images of Ki67 in the pancreas collected from PL and PLY mice 7 d after final TAM administration. (E) The representative IF images of GFP, CK19, and amylase in the pancreas collected from PL and PLY mice 7 d after final TAM administration. Quantification of average ADM numbers per 20× field using triple-positive GFP/CK19/amylase cells in PL mice was 330 ± 182.6 while PLY mice was 7 ± 6.557 with P value = .037. ADM = acinar to ductal metaplasia, GFP = green fluorescent protein, H&E = hematoxylin and eosin, IF = immunofluorescence, IHC = Immunohistochemistry, LATS1/2 = large tumor suppressor 1/2, PL = Ptf1a^CRE-ER Lats1^fl/fl Lats2^fl/fl Rosa26^LSL-YFP mice, PLY = Ptf1a^CreER Lats1^fl/fl Lats2^{fl/f l}Yap1^fl/fl Rosa26^LSL-YFP mice, SMA = smooth muscle actin, TAM = tamoxifen.

Figure 4.

TAZ is dispensable for the induction of pancreatic inflammation and damages in mice with LATS1/2 deficiency in acinar cells. (A) The representative H&E staining images of the pancreas collected from PL and PLT mice 7 d after final TAM administration. (B) The representative IHC images of YAP1, TAZ, and SPP1 in the pancreas collected from PL and PLT mice 7 d after final TAM administration. (C) The representative IF images of F4/80 and α-SMA in the pancreas collected from PL and PLT mice 7 d after final TAM administration. (D) The representative IHC images of Ki67 in the pancreas collected from PL and PLT mice 7 d after final TAM administration. (E) The representative IF images of GFP, CK19, and amylase in the pancreas collected from PL and PLT mice 7 d after final TAM administration. PL mice (n = 3) and PLT mice (n = 3). CK19 = cytokeratin 19, GFP = green fluorescent protein, H&E = hematoxylin and eosin, IF = immunofluorescence, IHC = Immunohistochemistry, LATS1/2 = large tumor suppressor 1/2, PL = Ptf1a^CRE-ER Lats1^fl/fl Lats2^fl/fl Rosa26^LSL-YFP mice, PLY = Ptf1a^CreER Lats1^fl/fl Lats2^{fl/f l}Yap1^fl/fl Rosa26^LSL-YFP mice, SMA = smooth muscle actin, TAM = tamoxifen.

Figure 5.

Yap1/Taz pharmaceutic inhibitor VT-104 ameliorate pancreatic damages induced by Lats1/2 ablation. (A) The schema of VT-104 treatment procedure. (B) The representative H&E staining images of the pancreas collected from saline-treated and VT-104-treated mice 7 d after final TAM administration. (C) The representative IF images of F4/80 and α-SMA in the pancreas collected from saline-treated and VT-104-treated mice 7 d after final TAM administration. (D) The representative IF images of GFP, CK19, and amylase in the pancreas collected from saline-treated and VT-104-treated mice 7 d after final TAM administration. Saline-treated mice (n = 3) and V-T104-treated mice (n = 5). CK19 = cytokeratin 19, GFP = green fluorescent protein, H&E = hematoxylin and eosin, IF = immunofluorescence, SMA = smooth muscle actin, TAM = tamoxifen.