title: Grp78 is essential for 11-deoxy-16,16-dimethyl PGE2-mediated cytoprotection in renal epithelial cells.
abstract: 11-Deoxy-16,16-dimethyl PGE(2) (DDM-PGE(2)) protects renal proximal tubule epithelial cells (LLC-PK(1)) against the toxicity induced by 2,3,5-tris(glutathion-S-yl)hydroquinone (TGHQ), a potent nephrotoxic and nephrocarcinogenic metabolite of hydroquinone. We have now determined the ability of DDM-PGE(2) to protect against other renal toxicants and report that DDM-PGE(2) only protects against oncotic cell death, induced by H(2)O(2), iodoacetamide, and TGHQ, but not against apoptotic cell death induced by cisplatin, mercuric chloride, or tumor necrosis factor-alpha. DDM-PGE(2)-mediated cytoprotection is associated with the upregulation of at least five proteins, including the major endoplasmic reticulum (ER) chaperone glucose-regulated protein 78 (Grp78). To elucidate the role of Grp78 in oncotic cell death, we used LLC-PK(1) cells in which induction of grp78 expression was disrupted by stable expression of an antisense grp78 RNA (pkASgrp78). As anticipated, DDM-PGE(2) failed to induce Grp78 in pkASgrp78 cells, with a concomitant inability to provide cytoprotection. In contrast, DDM-PGE(2) induced Grp78 and afforded cytoprotection against H(2)O(2), iodoacetamide, and TGHQ in empty vector transfected cells (pkNEO). These data suggest that Grp78 plays an essential role in DDM-PGE(2)-mediated cytoprotection. Moreover, TGHQ-induced p38 MAPK activation is disrupted under conditions of a compromised ER stress response in pkASgrp78 cells, which likely contributes to the loss of cytoprotection. Finally, using two-dimensional gel electrophoresis coupled to matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy, we found that DDM-PGE(2) induced several proteins in pkNEO cells, but not in pkASgrp78 cells, including retinol-binding protein, myosin light chain, and heat shock protein 27. The findings suggest that additional proteins may act in concert with Grp78 during DDM-PGE(2)-mediated cytoprotection against oncotic cell death.
authors.affiliation: Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona Health Sciences Center, 1703, E. Mabel St., Tucson, AZ 85721-0207, USA.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Jia
authors.forename: Maria D
authors.initials: MD
authors.lastname: Person
authors.forename: Jing
authors.initials: J
authors.lastname: Dong
authors.forename: Jianjm
authors.initials: J
authors.lastname: Shen
authors.forename: Sean C
authors.initials: SC
authors.lastname: Hensley
authors.forename: James L
authors.initials: JL
authors.lastname: Stevens
authors.forename: Terrence J
authors.initials: TJ
authors.lastname: Monks
authors.forename: Serrine S
authors.initials: SS
authors.lastname: Lau
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D019610:Cytoprotection / Q000502:physiology*; D015232:Dinoprostone / Q000031:analogs & derivatives* / Q000494:pharmacology; D015180:Electrophoresis, Gel, Two-Dimensional; D000091342:Endoplasmic Reticulum Chaperone BiP; D004847:Epithelial Cells / Q000187:drug effects / Q000473:pathology; D015870:Gene Expression / Q000187:drug effects; D005978:Glutathione / Q000031:analogs & derivatives* / Q000633:toxicity; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D006873:Hydroquinones / Q000633:toxicity; D047908:Intracellular Signaling Peptides and Proteins; D007460:Iodoacetamide / Q000633:toxicity; D007674:Kidney Diseases / Q000139:chemically induced* / Q000473:pathology / Q000517:prevention & control*; D007687:Kidney Tubules, Proximal / Q000187:drug effects* / Q000473:pathology; D018832:Molecular Chaperones / Q000235:genetics / Q000502:physiology*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D016372:RNA, Antisense / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism; D000099190:MAP-Kinase-Activated Kinase 2
chemical_list: D015232:Dinoprostone; D000091342:Endoplasmic Reticulum Chaperone BiP; D005978:Glutathione; D006360:Heat-Shock Proteins; D006861:Hydrogen Peroxide; D006873:Hydroquinones; D047908:Intracellular Signaling Peptides and Proteins; D007460:Iodoacetamide; D018832:Molecular Chaperones; D017346:Protein Serine-Threonine Kinases; D016372:RNA, Antisense; D048051:p38 Mitogen-Activated Protein Kinases; D000099190:MAP-Kinase-Activated Kinase 2; C481059:11-deoxy,16,16-dimethyl prostaglandin E(2); C000717247:HSPA5 protein, human; C078765:2,3,5-(triglutathion-S-yl)hydroquinone