title: Hormetic effects of acute methylmercury exposure on grp78 expression in rat brain cortex.
abstract: This study aims to explore the expression of GRP78, a marker of endoplasmic reticulum (ER) stress, in the cortex of rat brains acutely exposed to methylmercury (MeHg). Thirty Sprague-Dawley (SD) rats were randomly divided into six groups, and decapitated 6 hours (h) after intraperitoneal (i.p.) injection of MeHg (2, 4, 6, 8 or 10 mg/kg body weight) or normal saline. Protein and mRNA expression of Grp78 were detected by western blotting and real-time PCR, respectively. The results showed that a gradual increase in GRP78 protein expression was observed in the cortex of rats acutely exposed to MeHg (2, 4 or 6 mg/kg). Protein levels peaked in the 6 mg/kg group (p < 0.05 vs. controls), decreased in the 8 mg/kg group, and bottomed below the control level in the 10 mg/kg group. Parallel changes were noted for Grp78 mRNA expression. It may be implied that acute exposure to MeHg induced hormetic dose-dependent changes in Grp78 mRNA and protein expression, suggesting that activation of ER stress is involved in MeHg-induced neurotoxicity. Low level MeHg exposure may induce GRP78 protein expression to stimulate endogenous cytoprotective mechanisms.
authors.affiliation: Department of Preventive Medicine, School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.forename: Rongzhu
authors.initials: R
authors.lastname: Lu
authors.forename: Wenshuai
authors.initials: W
authors.lastname: Liu
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.forename: Hai
authors.initials: H
authors.lastname: Qian
authors.forename: Xiaowu
authors.initials: X
authors.lastname: Zhao
authors.forename: Suhua
authors.initials: S
authors.lastname: Wang
authors.forename: Guangwei
authors.initials: G
authors.lastname: Xing
authors.forename: Feng
authors.initials: F
authors.lastname: Yu
authors.forename: Michael
authors.initials: M
authors.lastname: Aschner
keywords: GRP78; Methylmercury; cortex; endoplasmic reticulum stress; rat
references.citation: Toxicol Lett. 1987 May;36(3):213-20
references.pmid: 3590217
references.citation: Food Chem Toxicol. 2011 Dec;49(12):3258-71
references.pmid: 21967782
references.citation: Cell Death Differ. 2004 Apr;11(4):365-8
references.pmid: 14685161
references.citation: FASEB J. 1994 Jun;8(9):622-9
references.pmid: 7516300
references.citation: Trends Pharmacol Sci. 2001 Jun;22(6):285-91
references.pmid: 11395156
references.citation: Toxicol Appl Pharmacol. 2000 Mar 15;163(3):260-6
references.pmid: 10702365
references.citation: Hum Exp Toxicol. 2000 Jul;19(7):420-30
references.pmid: 11002392
references.citation: Environ Sci Technol. 2010 Jan 1;44(1):469-75
references.pmid: 20039754
references.citation: Environ Health Perspect. 2002 Oct;110 Suppl 5:851-4
references.pmid: 12426145
references.citation: FEBS Lett. 2007 May 15;581(10):2055-9
references.pmid: 17475259
references.citation: J Neurochem. 1977 Oct;29(4):673-9
references.pmid: 145470
references.citation: Cell Calcium. 2003 Oct-Nov;34(4-5):345-63
references.pmid: 12909081
references.citation: Int J Biochem Cell Biol. 2009 Mar;41(3):531-8
references.pmid: 18765291
references.citation: Cell. 2000 May 26;101(5):451-4
references.pmid: 10850487
references.citation: Curr Opin Cell Biol. 2011 Apr;23(2):150-6
references.pmid: 20970977
references.citation: Toxicol Appl Pharmacol. 2011 Nov 1;256(3):405-17
references.pmid: 21601588
references.citation: J Neurochem. 1966 Nov;13(11):1223-30
references.pmid: 4224322
references.citation: J Huazhong Univ Sci Technolog Med Sci. 2009 Aug;29(4):492-7
references.pmid: 19662369
references.citation: J Clin Invest. 2002 Nov;110(10):1389-98
references.pmid: 12438434
references.citation: Environ Health Perspect. 2010 Aug;118(8):1137-45
references.pmid: 20529764
references.citation: Brain Res Bull. 2001 May 15;55(2):197-203
references.pmid: 11470315
references.citation: Int J Dev Neurosci. 2007 Nov;25(7):455-63
references.pmid: 17913437
references.citation: Trends Biochem Sci. 2001 Aug;26(8):504-10
references.pmid: 11504627
references.citation: Toxicol Sci. 2010 Apr;114(2):378-86
references.pmid: 20071421
references.citation: Toxicol Sci. 2011 Dec;124(2):446-59
references.pmid: 21908765
references.citation: Wei Sheng Yan Jiu. 2010 May;39(3):271-4
references.pmid: 20568450
references.citation: J Clin Invest. 2005 Oct;115(10):2656-64
references.pmid: 16200199
references.citation: Exp Gerontol. 2006 Oct;41(10):935-9
references.pmid: 17067771
references.citation: Acta Pharmacol Toxicol (Copenh). 1981 Nov;49(5):422-6
references.pmid: 7345883
references.citation: Exp Neurol. 1999 Feb;155(2):302-14
references.pmid: 10072306
references.citation: Neurosci Lett. 2001 Dec 4;316(1):5-8
references.pmid: 11720765
references.citation: J Pharmacol Exp Ther. 1993 Sep;266(3):1626-35
references.pmid: 8371160
references.citation: Neurosci Lett. 2011 Oct 31;504(3):271-6
references.pmid: 21970967
references.citation: Neurotox Res. 2001 Nov;3(6):581-9
references.pmid: 15111246
references.citation: Mol Chem Neuropathol. 1997 Aug;31(3):225-33
references.pmid: 9336765
references.citation: Cell Death Differ. 2007 Aug;14(8):1467-74
references.pmid: 17464326
references.citation: Hum Exp Toxicol. 2001 Jul;20(7):347-58
references.pmid: 11530833
references.citation: Neurotoxicology. 2008 Jan;29(1):22-30
references.pmid: 17920127
references.citation: Biochim Biophys Acta. 2009 Oct;1790(10):1030-9
references.pmid: 19463497
references.citation: Environ Toxicol Chem. 2010 Mar;29(3):650-3
references.pmid: 20821490
references.citation: Genes Dev. 1999 May 15;13(10):1211-33
references.pmid: 10346810
references.citation: Environ Health Prev Med. 2011 Jan;16(1):16-24
references.pmid: 21432213
references.citation: Nature. 2000 Jan 6;403(6765):98-103
references.pmid: 10638761
references.citation: Environ Res. 2011 Nov;111(8):1074-82
references.pmid: 22000760
references.citation: Mutat Res. 2005 Jan 6;569(1-2):29-63
references.pmid: 15603751
references.citation: Arch Environ Contam Toxicol. 2012 Jan;62(1):141-4
references.pmid: 21604054
references.citation: Nature. 1999 Jan 21;397(6716):271-4
references.pmid: 9930704
references.citation: Trends Cell Biol. 2004 Jan;14(1):20-8
references.pmid: 14729177
references.citation: Environ Health Perspect. 2006 Jun;114(6):859-64
references.pmid: 16759985
references.citation: J Neurosci Res. 1999 Jul 1;57(1):48-61
references.pmid: 10397635
references.citation: Drug Metab Rev. 2005;37(3):405-42
references.pmid: 16257829
references.citation: Toxicol Appl Pharmacol. 2010 Oct 15;248(2):156-64
references.pmid: 20691719
references.citation: Chem Biol Interact. 2010 Nov 5;188(2):301-8
references.pmid: 20399200
references.citation: Ageing Res Rev. 2008 Jan;7(1):1-7
references.pmid: 18162444
references.citation: Int J Environ Res Public Health. 2010 Jun;7(6):2666-91
references.pmid: 20644695
references.citation: Met Ions Life Sci. 2010;7:403-34
references.pmid: 20877814
references.citation: Chemosphere. 2011 Apr;83(4):552-63
references.pmid: 21195448
references.citation: Toxicol Appl Pharmacol. 1989 Jul;99(3):510-21
references.pmid: 2568702