Figure 1.

Calreticulin is an ER stress–inducible gene. A, hepatic CRT expression is increased under ER stress. Male C57BL/6 mice 8 weeks old were intraperitoneally injected with tunicamycin (1 mg/kg of body weight) or vehicle (PBS), sacrificed 48 h later for liver lysates, and assayed by immunoblotting. Three representative samples of each group are shown. B, densitometric quantification of expression of calreticulin, the ratio of LC3-II to LC3-I, and GRP78. C and D, the protein levels of calreticulin were increased in HeLa cells treated with gradient dosages of tunicamycin (C) or thapsigargin (D) for 16 h. The band intensity of LC3-II was quantified by densitometry and normalized to the levels of LC3-I. E and F, the relative mRNA levels of calreticulin (E) and UPR mediators (F) were increased in HeLa cells treated with gradient dosages of tunicamycin for 16 h. Data are presented as the mean ± S.E.; n = 4. *, p < 0.05 versus chow and vehicle.