Induction of Protein Disulfide Isomerase mRNA by Δ12-Prostaglandin J2

PPARγ ligands induce ER stress in pancreatic β-cells: ER stress activation results in attenuation of cytokine signaling

“…PPAR␥ activation does not appear to be required for UPR activation, as PGJ 2 stimulates HSP70 expression and inhibits cytokine signaling in RINm5F cells expressing dominant negative mutants of PPAR␥ or treated with the PPAR␥ antagonist GW-9622 (42). PGJ 2 has been shown to localize to the ER (39), and this localization is associated with increased expression of BiP and protein disulfide isomerase (25,26). In addition, we have shown that PGJ 2 stimulates tissue transglutaminase activity in RINm5F cells, and the resulting cross-linking of proteins may be the mechanism by which these ligands stimulate ER stress in ␤-cells (Weber SM and Corbett JA, unpublished observation).…”

PGJ2-stimulated β-cell apoptosis is associated with prolonged UPR activation

“…These findings support a PPAR␥-independent mechanism of UPR activation. PGJ 2 has been shown to localize to the ER, and this localization is associated with enhanced expression of GRP78 (BiP) and protein disulfide isomerase (43,44), suggesting that the actions of PGJ 2 are ER directed. Our findings suggest that PGJ 2 may exert effects directly or indirectly at the plasma membrane as the levels of cell death induced by PGJ 2 significantly differ depending on the biochemical assay being performed.…”

Localization of a cyclopentenone prostaglandin to the endoplasmic reticulum and induction of BiP mRNA

“…Among them, the prominent action of cyclopentenone PGs is a stress response. Cyclopentenone PGs are produced in response to various stress stimuli, and are then actively transported into cells and induce the expression of various stress-related protein genes, including those of a family of cytosolic heat-shock proteins [5,6], ribosome-inactivating protein [7], haem oxygenase [8], protein disulphide-isomerase [9] and BiP (an ER luminal protein) [10].…”