Thymosin β4 released by mast cells under stress conditions impairs intestinal epithelial barrier via IL22RA1/JAK1/STAT3 signaling in irritable bowel syndrome

Figure 7 Thymosin β4 released from mast cells mediates intestinal barrier permeability. A: Schematic illustration of peritoneal mast cell (PMC) reconstitution; B: The concentration of thymosin β4 (Tβ4) in rat serum after six weeks. Tβ4^−/− rats and Tβ4^−/− > wild-type (wt)-PMCs were treated with corticotropin-releasing hormone. Bar, SD, ^aP < 0.001 vs the WT group, ^bP < 0.001 vs the Tβ4^−/− group; C: Representative images of cell shedding using luminal acriflavine (green) and rhodamine B-dextran (red). Scale bar, 100 μm; D: FITC-dextran 4000 (FD4, 4 kDa, 5 mg/kg) was orally administered, and the flux of FITC-dextran in rat serum was observed 3 hours later. Bar, SD, ^cP < 0.05 vs the “Tβ4^−/− > wt-PMCs” group; E: Representative intestinal immunofluorescence images of zonulin 1. Scale bar, 50 μm; F: Representative FISH staining for bacterial infiltration using EUB338 probe (red) and DAPI (blue). Scale bar, 100 μm. Tβ4: Thymosin β4; WT: Wild-type; PMC: Peritoneal mast cells.