NKX6.3 protects against gastric mucosal atrophy by downregulating β-amyloid production

Figure 4 Amyloid β induces cell death in gastric epithelial cells. A: Treatment with recombinant amyloid β (rAβ) 1-42 produced oligomeric forms of Aβ in HFE-145^shNKX6.3 cells, but not in HFE-145^shCtrl cells. Recombinant gastrokine 1 (rGKN1) partially reduced expression of Aβ oligomers. B: Treatment with rAβ 1-42 did not affect viability of HFE-145^shCtrl cells, although it significantly decreased viability of HFE-145^shNKX6.3 cells in a time dependent manner. Shown are the means ± SEM from three experiments. Superscript letter represents significant difference (^aP < 0.05, ^bP < 0.005 and ^cP < 0.0001). C: Floating cell population was markedly increased in HFE-145^shNKX6.3 cells treated with rAβ 1-42. Shown are the means ± SEM from three experiments. Superscript letter represents significant difference (^dP < 0.001). D: In HFE-145^shNKX6.3 cells, treatment with rAβ 1-42 for 72 hrs decreased cell viability while treatment with rGKN1 revoked the effect of rAβ on cell viability. Shown are the means ± SEM from three experiments. Superscript letter represents significant difference (^eP < 0.05 and ^fP < 0.005). rAβ: Recombinant amyloid β; rGKN1: Recombinant gastrokine 1; Aβ: Amyloid β.