摘要
Clusterinisa75-80kDaheterodimericglycoprotein,thatisproducedinmosttissuesbutwhichexactbiologicalroleisstillnotclear.Particularly,itsroleinprotectionorpromotionofapoptosisisheavilydisputed,sincedatasupportingbothviewshavebeenreportedinseveralindependentstudies.Toclarifythisissue,andalsotodeterminewhetherclusterinexpressionitselfmightbeaffectedbyapoptosis,inthepresentstudy,ratthymocytesweretreatedwithdexamethasone,-asyntheticglucocorticoidthatelicitsapoptosisinthymocytes-,andclusterinmRNAexpressionwasanalyzedbysemi-quantitativeRT-PCRbeforeandafterinductionofapoptosis.Interestingly,neitherthetreatmentwithdexamethasoneinvitronortriggeringofapoptosisinvivoup-regulatedclusterinexpression,opposingtheviewthatclusterinisinvolvedinapoptoticprocesses.Ontheotherhand,anewclusterinmRNAisoformwasdetectedandisolated,whoseexpressionwasrestrictedtofreshlyisolatedthymocytes.Thisnovelisoformlacksthepost-translationalproteolyticcleavagesiteandisthereforepredictedtoencodeamonomericprotein.Thebiologicalfunctionundernormalcircumstances,however,willneedfurtherinvestigationsforclarification.Whileapoptosiscouldnotmodulateclusterinexpression,activationofthymocyteswithconcanavalinAandinterleukin-2resultedinup-regulationofclusterinmRNAlevel,indicatingthatclusterinexpressionisratherunderthecontrolofcellactivation-mediatedratherthanapoptosis-inducedsignals.
出版日期
2003年01月11日(中国期刊网平台首次上网日期,不代表论文的发表时间)