Figure 1

PSP/reg is induced by endoplasmic reticulum stress. (A–D) INS-1 832/13 cells were transfected with siRNA directed against WFS1 (siWFS1) or control scrambled siRNA (siScr). Quantitative real-time PCR was used to measure gene expression of (A) Reg1, (B) Bip (C) Chop, and (D) Txnip. Knockdown of WFS1 increased Reg1 expression 5-fold. Bip expression was increased by ~70%, Chop expression by ~25%, and Txnip expression by ~25%, relative to control. (E–H) INS-1 832/13 cells were treated with two chemical inducers of ER stress, tunicamycin (TM) and thapsigargin (TG), at the doses specified. DMSO was used as a vehicle control. Quantitative real-time PCR was used to measure gene expression of (E) Reg1, (F) Bip (G) Chop, and (H) Txnip. The expression of Reg1 was significantly increased by TM and TG after 8 hours of treatment. As expected, TM and TG treatment led to upregulation of Bip, Chop and Txnip. *p < 0.05, **p < 0.01. Statistical significance was determined by an unpaired two-tailed t-test between a treated condition and its corresponding control condition.