Dysregulated signal transducer and activator of transcription 3 drives intestinal permeability and may contribute to acute-on-chronic liver failure

Figure 5 Immunofluorescence staining and transmission electron microscopy verify deconstructed monolayer architecture in enhanced as well as reduced signal transducer and activator of transcription 3 expressing Caco-2 and T84 monolayers. Differential signal transducer and activator of transcription 3 (STAT3) expressing Caco-2 and T84 cell lines were grown over a period of 28 days and the formation of Caco-2 and T84 monolayers was verified during this period. A and B: Caco-2 (A) T84 (B) monolayers were fixed, permeabilized, incubated with anti zonula occludens-1, and subsequently stained with a fluorescent-labeled antibody. Nuclei were counterstained with 4’,6-diamidino-2-phenylindole. Imaging was performed using a Keyence BZ X810 fluorescence microscope; C and D: In parallel, Caco-2 (C) and T84 (D) monolayers were prepared for transmission electron microscopy (TEM). Immunofluorescence as well as TEM showed the deconstructed architecture in enhanced STAT3 (STAT3 +) as well as reduced STAT3 (STAT3 -) expressing monolayers. Orange arrows = gaps at cell boundaries, black arrows = location of tight junctions. STAT3: Signal transducer and activator of transcription 3; DAPI: 4’,6-diamidino-2-phenylindole; ZO-1: Zonula occludens-1.