Hippo signaling pathway activation during SARS-CoV-2 infection contributes to host antiviral response
Fig 3
ShRNA-mediated knockdown and pharmacological modulation of SARS-CoV-2 replication.
(A) IHC analysis of shRNA-mediated knockdown of YAP1 and LATS1-specific shRNAs showed efficiently reduced or increased SARS-CoV-2 replication (green) relative to shRNA control, respectively, in hPSC-CMs. Scale bar: 50 μm. (B) Western blot analysis of shRNA-mediated knockdown of YAP1 and LATS1 respective protein expression. (Con: Control shRNA). (C) IHC images of XMU-MP-1 (MST1/2 inhibitor) and vehicle-treated hPSC-CMs are shown. Note: XMU-MP-1 increased SARS-CoV-2 replication (green) in hPSC-CM. (D) Graphs depict quantification of SARS-CoV-2 positive cells in infected hPSC-CM respective to panels A and C. Data represented as the average of technical replicates and SEM. Student t test. **P > 0.001; n = 2 independent experiments. (E) IHC Images show YAP/TAZ protein (green) and SARS-CoV-2 Spike antigen (red) in Calu-3 cells. Note, MST1/2 inhibitor-treated Calu-3 cells have higher number of infected cells. Inset and white asterisk hovers infected cells showing depletion of YAP/TAZ. Scale bar: 25 μm. Inset scale bar: 10 μm. (F) Western blot analysis of Calu-3 cells treated with Verteporfin (1 μm) and SARS-CoV-2 infection. Drug treatment resulted in reduction in SARS-CoV-2 infection. Graph shows the viral titer (TCID50/ml) measurement of infected as well as treated Calu-3 culture supernatant (representative data from 2 independent experiments). (G) Schematic diagram of our hypothetical model integrating Hippo and TBK1 signaling pathways during preinfection (Hippo off) and SARS-CoV-2 infection states (Hippo on). c-GAS, cyclic GMP-AMP synthase; IKKe, inhibitor of nuclear factor kappa B kinase subunit epsilon; MAVS, mitochondrial antiviral-signaling protein; RIG-I, retinoic acid inducible gene I protein; STING, stimulator of interferon response cGAMP interactor 1; TEAD, TEA domain transcription factors. Individual quantitative observations that underlie the data summarized in Fig 3D and 3F can be located under the Supporting Information File as S2 and S3 Data files, respectively. hPSC-CM, human pluripotent stem cell-derived cardiomyocyte; SARS‑CoV‑2, Severe Acute Respiratory Syndrome Coronavirus 2.