Fig 2: Clusterin expression in oxyntic mucosa increases and localization shifts from neuroendocrine cells to chief cells after sustained hypoacidity and hypergastrinemia.(A) IHC and ISH showing similar expression patterns for clusterin (brown) protein and mRNA, examined in control (n = 8) and hypergastrinemic PPI-rats (n = 6). (B) Number of CLU-positive/VMAT2(neuroendocrine (NE))-positive cells and CLU-positive/VMAT2(NE)-negative cells per oxyntic gland (n = 4 rats per group). (C) Double immunofluorescence staining of oxyntic mucosa from hypergastrinemic PPI-rats showing scarce CLU (green) expression in ECL cells (VMAT2-positive (red)). (D) Double immunofluorescence staining of oxyntic mucosa from hypergastrinemic PPI-rats showing CLU (green) expression in groups of chief cells (MIST1-positive (purple)) and triple immunofluorescence staining showing CLU (green) expression in proliferating (PCNA-positive (light blue)) chief cells (PGA5 (red)). Ctr = control; PPI = PPI-induced hypergastrinemia; CCK2Ra = CCK2R antagonist; PPI+CCK2Ra = PPI-induced hypergastrinemia+CCK2R antagonist. Data presented as means ± SEM. *, ** and # = ANOVA with Bonferroni-adjusted p value < 0.05. (*comparison of CLU+/NE+ cells per gland in control vs other groups individually; **comparison of CLU+/NE- cells per gland in PPI vs control or CCK2Ra; #comparison of CLU+/NE- cells per gland in PPI+CCK2Ra vs CCK2Ra.) Nuclei were counterstained with hematoxylin (blue) or DAPI (blue). The basal zone (~100 µm from the gland bottom) is highlighted with a dotted line. Scale bars = (A) 100 µm; (C, D) 50 µm.