www.nrronline.orgShiZhaoandLinZhangcontributedequallytothisstudy.Correspondingauthor:ShiZhao,Professor,Master’ssupervisor,Chiefphysician,DepartmentofEndocrinology,WuhanCentralHospital,Wuhan430014,HubeiProvince,China,zhaoshiwuhan@126.com.Received:2013-08-29Accepted:2013-11-02(N201304023)Acknowledgments:TheauthorswouldliketothankXuZHfromtheDepartmentofEndocrinology,WuhanCentralHospital,Wuhan,HubeiProvince,Chinaforassistingwithpapereditinganddatadiscussion.Funding:ThestudywassupportedbytheNaturalScienceFoundationofHubeiProvince,No.2010CDB09001.NEURALREGENERATIONRESEARCHVolume8,Issue36,December2013doi:10.3969/j.issn.1673-5374.2013.36.008[http://www.nrronline.org;http://www.sjzsyj.org]ZhaoS,ZhangL,XuZH,ChenWQ.Neurotoxiceffectsofironoverloadunderhighglucoseconcentration.NeuralRegenRes.2013;8(36):3423-3433.Neurotoxiceffectsofironoverloadunderhighglucoseconcentration*ShiZhao1,LinZhang1,ZihuiXu1,WeiqunChen21DepartmentofEndocrinology,WuhanCentralHospital,Wuhan430014,HubeiProvince,China2CentralLaboratory,WuhanCentralHospital,Wuhan430014,HubeiProvince,ChinaGraphicalAbstractAbstractIronoverloadcanleadtocytotoxicity,anditisariskfactorfordiabeticperipheralneuropathy.However,theunderlyingmechanismremainsunclear.Weconjecturedthatironoverload-inducedneurotoxicitymightbeassociatedwithoxidativestressandtheNF-E2-relatedfactor2(Nrf2)/AREsignalingpathway.Asaninvitrocellularmodelofdiabeticperipheralneuropathy,PC12cellsex-posedtohighglucoseconcentrationwereusedinthisstudy.PC12cellswereculturedwithferricammoniumcitrateatdifferentconcentrationstocreateironoverload.PC12cellsculturedinferricammoniumcitrateunderhighglucoseconcentrationhadsignificantlylowcellviability,ahighrateofapoptosis,andelevatedreactiveoxygenspeciesandmalondialdehydelevels.Thesechangesweredependentonferricammoniumcitrateconcentration.Nrf2mRNAandproteinexpressionintheferricammoniumcitrategroupswereinhibitedmarkedlyinadose-dependentmanner.All3423ZhaoS,etal./NeuralRegenerationResearch.2013;8(36):3423-3433.changescouldbeinhibitedbyadditionofdeferoxamine.TheseresultsindicatethatironoverloadaggravatesoxidativestressinjuryinneuralcellsunderhighglucoseconcentrationandthattheNrf2/AREsignalingpathwaymightplayanimportantroleinthisprocess.KeyWordsneuralregeneration;peripheralnerveinjury;ironoverload;oxidativestress;diabeticperipheralneuropathy;reactiveoxygenspecies;highglucose;PC12cells;Nrf2/ARE;grants-supportedpaper;neuroregenera-tionINTRODUCTIONDiabeticperipheralneuropathyisoneofmostcommonchroniccomplicationsinducedbydiabetichyperglycemia,andisassociatedwithaxonalatrophy,bluntedregenerativepo-tential,demyelination,andlossofperipheralnervefibers[1].Althoughnumerousfactorscontributetodiabeticperipheralneuropathy,includinginsulin-inducedresistancetoneu-ronaltrophicsupport[2],decreased(Na/K)-ATP-aseactivity[3]andSchwanncelldysfunc-tion[4],increasedoxidativestressandmito-chondrialdysfunctionseemintimatelyasso-ciatedwithnervedysfunctionanddiminishedregenerativecapacity.Oxidativestressandapoptosishavebeenfoundtoplaycrucialrolesindiabeticperipheralneuropathy[5-6].Underhyperglycemia,largeamountsofre-activeoxygenspeciesareproducedbythemitochondrialrespiratorychain,andneu-ronalapoptosisisincreased[7].Despitead-vancesinunderstandingtheetiologyofdia-beticperipheralneuropathy,fewapprovedtherapiesexistforthepharmacologicalman-agementofthedisease.Theref...