Acknowledgments The authors thank Dr. Byron Grove and Sarah Rolling (Department of Anatomy and Cell Biology, School of Medicine & Health Sciences, University of North Dakota) for their technical assistance in confocal microscopy. References 1. Querfurth HW, LaFerla FM (2010) Alzheimer’s disease. N Engl J Med 362: 329–344. 2. Ghribi O, Golovko MY, Larsen B, Schrag M, Murphy EJ (2006) Deposition of iron and beta-amyloid plaques is associated with cortical cellular damage in rabbits fed with long-term cholesterol-enriched diets. J Neurochem 99: 438–449. 3. McCullough KD, Martindale JL, Klotz LO, Aw TY, Holbrook NJ (2001) Gadd153 sensitizes cells to endoplasmic reticulum stress by down-regulating Bcl2 and perturbing the cellular redox state. Mol Cell Biol 21: 1249–1259. 4. Oyadomari S, Mori M (2004) Roles of CHOP/GADD153 in endoplasmic reticulum stress. Cell Death Differ 11: 381–389. 5. Vecchi C, Montosi G, Zhang K, Lamberti I, Duncan SA, et al. (2009) ER stress controls iron metabolism through induction of hepcidin. Science 325: 877–880. 6. Tamagno E, Bardini P, Obbili A, Vitali A, Borghi R, et al. (2002) Oxidative stress increases expression and activity of BACE in NT2 neurons. Neurobiol Dis 10: 279–288. 7. Tamagno E, Guglielmotto M, Bardini P, Santoro G, Davit A, et al. (2003) Dehydroepiandrosterone reduces expression and activity of BACE in NT2 neurons exposed to oxidative stress. Neurobiol Dis 14: 291–301. 8. Marwarha G, Dasari B, Prasanthi JRP, Schommer J, Ghribi O (2010) Leptin reduces the accumulation of Abeta and phosphorylated tau induced by 27- hydroxycholesterol in rabbit organotypic slices. J Alzheimers Dis 19: 1007–1019. 9. Prasanthi JRP, Huls A, Thomasson S, Thompson A, Schommer E, et al. (2009) Differential effects of 24-hydroxycholesterol and 27-hydroxycholesterol on beta- amyloid precursor protein levels and processing in human neuroblastoma SH- SY5Y cells. Mol Neurodegener 4: 1. 10. Sharma S, Prasanthi RPJ, Schommer E, Feist G, Ghribi O (2008) Hypercholesterolemia-induced Abeta accumulation in rabbit brain is associated with alteration in IGF-1 signaling. Neurobiol Dis 32: 426–432. 11. Graur D, Duret L, Gouy M (1996) Phylogenetic position of the order Lagomorpha (rabbits, hares and allies). Nature 379: 333–335. 12. Johnstone EM, Chaney MO, Norris FH, Pascual R, Little SP (1991) Conservation of the sequence of the Alzheimer’s disease amyloid peptide in dog, polar bear and five other mammals by cross-species polymerase chain reaction analysis. Brain Res Mol Brain Res 10: 299–305. 13. Prasanthi JRP, Dasari B, Marwarha G, Larson T, Chen X, et al. (2010) Caffeine protects against oxidative stress and Alzheimer’s disease-like pathology in rabbit hippocampus induced by cholesterol-enriched diet. Free Radic Biol Med 49: 1212–1220. 14. Petrat F, de GH, Rauen U (2000) Determination of the chelatable iron pool of single intact cells by laser scanning microscopy. Arch Biochem Biophys 376: 74–81. 15. Hacki J, Egger L, Monney L, Conus S, Rosse T, et al. (2000) Apoptotic crosstalk between the endoplasmic reticulum and mitochondria controlled by Bcl-2. Oncogene 19: 2286–2295. 16. Malhotra JD, Miao H, Zhang K, Wolfson A, Pennathur S, et al. (2008) Antioxidants reduce endoplasmic reticulum stress and improve protein secretion. Proc Natl Acad Sci U S A 105: 18525–18530. 17. Connor JR, Menzies SL, St Martin SM, Mufson EJ (1992) A histochemical study of iron, transferrin, and ferritin in Alzheimer’s diseased brains. J Neurosci Res 31: 75–83. 18. Connor JR, Snyder BS, Beard JL, Fine RE, Mufson EJ (1992) Regional distribution of iron and iron-regulatory proteins in the brain in aging and Alzheimer’s disease. J Neurosci Res 31: 327–335. 19. Loeffler DA, Connor JR, Juneau PL, Snyder BS, Kanaley L, et al. (1995) Transferrin and iron in normal, Alzheimer’s disease, and Parkinson’s disease brain regions. J Neurochem 65: 710–724. 20. Thompson CM, Markesbery WR, Ehmann WD, Mao YX, Vance DE (1988) Regional brain trace-element studies in Alzheimer’s disease. Neurotoxicology 9: 1–7. 21. Whitnall M, Richardson DR (2006) Iron: a new target for pharmacological intervention in neurodegenerative diseases. Semin Pediatr Neurol 13: 186–197. 22. Torti SV, Kwak EL, Miller SC, Miller LL, Ringold GM, et al. (1988) The molecular cloning and characterization of murine ferritin heavy chain, a tumor necrosis factor-inducible gene. J Biol Chem 263: 12638–12644. 23. Tsuji Y, Miller LL, Miller SC, Torti SV, Torti FM (1991) Tumor necrosis factor-alpha and interleukin 1-alpha regulate transferrin receptor in human diploid fibroblasts. Relationship to the induction of ferritin heavy chain. J Biol Chem 266: 7257–7261. 24. Xu C, Bailly-Maitre B, Reed JC (2005) Endoplasmic reticulum stress: cell life and death decisions. J Clin Invest 115: 2656–2664. 25. Wang XZ, Lawson B, Brewer JW, Zinszner H, Sanjay A, et al. (1996) Signals from the stressed endoplasmic reticulum induce C/EBP-homologous protein (CHOP/GADD153). Mol Cell Biol 16: 4273–4280. Gadd153 Mediates 27-OHC-Induced AD Pathology Author Contributions Conceived and designed the experiments: JP OG. Performed the experiments: JP TL JS. Analyzed the data: JP OG. Contributed reagents/materials/analysis tools: JP TL JS OG. Wrote the paper: JP OG. 26. Cudna RE, Dickson AJ (2003) Endoplasmic reticulum signaling as a determinant of recombinant protein expression. Biotechnol Bioeng 81: 56–65. 27. Song B, Scheuner D, Ron D, Pennathur S, Kaufman RJ (2008) Chop deletion reduces oxidative stress, improves beta cell function, and promotes cell survival in multiple mouse models of diabetes. J Clin Invest 118: 3378–3389. 28. Tamaki N, Hatano E, Taura K, Tada M, Kodama Y, et al. (2008) CHOP deficiency attenuates cholestasis-induced liver fibrosis by reduction of hepatocyte injury. Am J Physiol Gastrointest Liver Physiol 294: G498–G505. 29. Feng B, Yao PM, Li Y, Devlin CM, Zhang D, et al. (2003) The endoplasmic reticulum is the site of cholesterol-induced cytotoxicity in macrophages. Nat Cell Biol 5: 781–792. 30. Thorp E, Li G, Seimon TA, Kuriakose G, Ron D, et al. (2009) Reduced apoptosis and plaque necrosis in advanced atherosclerotic lesions of Apoe2/2 and Ldlr2/2 mice lacking CHOP. Cell Metab 9: 474–481. 31. Vries-Seimon T, Li Y, Yao PM, Stone E, Wang Y, et al. (2005) Cholesterol- induced macrophage apoptosis requires ER stress pathways and engagement of the type A scavenger receptor. J Cell Biol 171: 61–73. 32. Eckert A, Keil U, Marques CA, Bonert A, Frey C, et al. (2003) Mitochondrial dysfunction, apoptotic cell death, and Alzheimer’s disease. Biochem Pharmacol 66: 1627–1634. 33. Eckert A, Marques CA, Keil U, Schussel K, Muller WE (2003) Increased apoptotic cell death in sporadic and genetic Alzheimer’s disease. Ann N Y Acad Sci 1010: 604–609. 34. Paradis E, Douillard H, Koutroumanis M, Goodyer C, LeBlanc A (1996) Amyloid beta peptide of Alzheimer’s disease downregulates Bcl-2 and upregulates bax expression in human neurons. J Neurosci 16: 7533–7539. 35. Marciniak SJ, Yun CY, Oyadomari S, Novoa I, Zhang Y, et al. (2004) CHOP induces death by promoting protein synthesis and oxidation in the stressed endoplasmic reticulum. Genes Dev 18: 3066–3077. 36. Smith MA, Zhu X, Tabaton M, Liu G, McKeel DW, Jr., et al. (2010) Increased iron and free radical generation in preclinical Alzheimer disease and mild cognitive impairment. J Alzheimers Dis 19: 363–372. 37. Rossner S, Sastre M, Bourne K, Lichtenthaler SF (2006) Transcriptional and translational regulation of BACE1 expression–implications for Alzheimer’s disease. Prog Neurobiol 79: 95–111. 38. Park SH, Choi HJ, Yang H, Do KH, Kim J, et al. (2010) Endoplasmic reticulum stress-activated C/EBP homologous protein enhances nuclear factor-kappaB signals via repression of peroxisome proliferator-activated receptor gamma. J Biol Chem 285: 35330–35339. 39. Imaizumi K, Miyoshi K, Katayama T, Yoneda T, Taniguchi M, et al. (2001) The unfolded protein response and Alzheimer’s disease. Biochim Biophys Acta 1536: 85–96. 40. Woltjer RL, Nghiem W, Maezawa I, Milatovic D, Vaisar T, et al. (2005) Role of glutathione in intracellular amyloid-alpha precursor protein/carboxy-terminal fragment aggregation and associated cytotoxicity. J Neurochem 93: 1047–1056. 41. Behl C, Davis JB, Lesley R, Schubert D (1994) Hydrogen peroxide mediates amyloid beta protein toxicity. Cell 77: 817–827. 42. Frederikse PH, Garland D, Zigler JS, Jr., Piatigorsky J (1996) Oxidative stress increases production of beta-amyloid precursor protein and beta-amyloid (Abeta) in mammalian lenses, and Abeta has toxic effects on lens epithelial cells. J Biol Chem 271: 10169–10174. 43. Carrell RW, Lomas DA (1997) Conformational disease. Lancet 350: 134–138. 44. Kim I, Xu W, Reed JC (2008) Cell death and endoplasmic reticulum stress: disease relevance and therapeutic opportunities. Nat Rev Drug Discov 7: 1013–1030. 45. Thomas PJ, Qu BH, Pedersen PL (1995) Defective protein folding as a basis of human disease. Trends Biochem Sci 20: 456–459. 46. Williams BL, Lipkin WI (2006) Endoplasmic reticulum stress and neurodegen- eration in rats neonatally infected with borna disease virus. J Virol 80: 8613–8626. 47. Milhavet O, Martindale JL, Camandola S, Chan SL, Gary DS, et al. (2002) Involvement of Gadd153 in the pathogenic action of presenilin-1 mutations. J Neurochem 83: 673–681. 48. Yang M, Omura S, Bonifacino JS, Weissman AM (1998) Novel aspects of degradation of T cell receptor subunits from the endoplasmic reticulum (ER) in T cells: importance of oligosaccharide processing, ubiquitination, and protea- some-dependent removal from ER membranes. J Exp Med 187: 835–846. 49. Kakimura J, Kitamura Y, Taniguchi T, Shimohama S, Gebicke-Haerter PJ (2001) Bip/GRP78-induced production of cytokines and uptake of amyloid- beta(1-42) peptide in microglia. Biochem Biophys Res Commun 281: 6–10. 50. Yoo BC, Kim SH, Cairns N, Fountoulakis M, Lubec G (2001) Deranged expression of molecular chaperones in brains of patients with Alzheimer’s disease. Biochem Biophys Res Commun 280: 249–258. PLoS ONE | www.plosone.org 11 October 2011 | Volume 6 | Issue 10 | e26420