外泌體來(lái)源的Lnc-MALAT1通過(guò)β-連環(huán)蛋白信號(hào)通路促進(jìn)肝星狀細(xì)胞的活化及肝纖維化

外泌體來(lái)源的Lnc-MALAT1通過(guò)β-連環(huán)蛋白信號(hào)通路促進(jìn)肝星狀細(xì)胞的活化及肝纖維化摘要：肝纖維化是肝臟疾病中常見的一種，其早期診斷及防治具有重要意義。本文研究外泌體來(lái)源的Lnc-MALAT1通過(guò)β-連環(huán)蛋白信號(hào)通路促進(jìn)肝星狀細(xì)胞的活化及肝纖維化。研究結(jié)果表明，Lnc-MALAT1在肝星狀細(xì)胞中顯著上調(diào)，并且其高表達(dá)與肝纖維化的程度呈正相關(guān)。在肝星狀細(xì)胞中沉默Lnc-MALAT1可以顯著抑制其活化和IL-6表達(dá)。此外，Lnc-MALAT1可以調(diào)控β-連環(huán)蛋白信號(hào)通路，增強(qiáng)肝星狀細(xì)胞的遷移、增殖和膠原合成。因此，外泌體來(lái)源的Lnc-MALAT1通過(guò)β-連環(huán)蛋白信號(hào)通路促進(jìn)肝星狀細(xì)胞的活化及肝纖維化。本研究結(jié)果為肝纖維化的早期診斷及防治提供了一定的理論基礎(chǔ)。

關(guān)鍵詞：肝纖維化，Lnc-MALAT1，肝星狀細(xì)胞，β-連環(huán)蛋白信號(hào)通路，遷移，增殖，膠原合成

Introduction：肝纖維化是由多種慢性肝疾病所致的肝臟病變，其特征為肝臟纖維組織的增生和沉積，導(dǎo)致肝臟結(jié)構(gòu)和功能的破壞。肝星狀細(xì)胞是肝纖維化中的關(guān)鍵細(xì)胞，可以分泌大量細(xì)胞外基質(zhì)和膠原等成分，導(dǎo)致肝纖維化的發(fā)生。Lnc-MALAT1是一種長(zhǎng)鏈非編碼RNA，已被證明在多種癌癥中具有重要作用。然而，其在肝纖維化中的生物學(xué)功能及作用機(jī)制尚不清楚。

Methods：本研究采用多種實(shí)驗(yàn)方法研究外泌體來(lái)源的Lnc-MALAT1在肝纖維化中的生物學(xué)功能及作用機(jī)制。首先，采用qPCR和Westernblot分析肝星狀細(xì)胞中Lnc-MALAT1和IL-6表達(dá)水平；其次，轉(zhuǎn)染shRNA沉默Lnc-MALAT1，并測(cè)定其對(duì)肝星狀細(xì)胞活化、膠原合成和細(xì)胞遷移的影響；最后，采用Westernblot分析β-連環(huán)蛋白家族成員的表達(dá)及活化情況。

Results：實(shí)驗(yàn)結(jié)果表明，在肝纖維化組織和細(xì)胞中，Lnc-MALAT1的表達(dá)水平明顯上調(diào)，并且與肝纖維化的程度呈正相關(guān)。在肝星狀細(xì)胞中沉默Lnc-MALAT1可以顯著抑制其活化和IL-6表達(dá)。此外，Lnc-MALAT1可以通過(guò)調(diào)控β-連環(huán)蛋白信號(hào)通路增強(qiáng)肝星狀細(xì)胞的遷移、增殖和膠原合成。

Conclusions：本研究結(jié)果表明，外泌體來(lái)源的Lnc-MALAT1通過(guò)β-連環(huán)蛋白信號(hào)通路促進(jìn)肝星狀細(xì)胞的活化及肝纖維化。這提供了一個(gè)新的理論基礎(chǔ)，為肝纖維化的早期診斷及防治提供了新的思路Introduction:

RNAencoding,whichreferstotheprocessoftranscribingDNAintoRNA,playsanimportantroleinthedevelopmentandprogressionofvariouscancers.However,itsbiologicalfunctionandmechanisminliverfibrosisremainunclear.Inthisstudy,weaimedtoinvestigatetheroleandmechanismofLnc-MALAT1inliverfibrosis.

Methods:

MultipleexperimentalmethodswereusedinthisstudytoinvestigatethebiologicalfunctionandmechanismofLnc-MALAT1fromexosomesinliverfibrosis.First,qPCRandWesternblotwereusedtoanalyzetheexpressionlevelsofLnc-MALAT1andIL-6inhepaticstellatecells.Second,shRNAwastransfectedtosilenceLnc-MALAT1,andtheeffectsofthisonhepaticstellatecellactivation,collagensynthesis,andcellmigrationweredetermined.Finally,theexpressionandactivationofbeta-cateninfamilymemberswereanalyzedbyWesternblot.

Results:

TheresultsshowedthattheexpressionlevelofLnc-MALAT1wassignificantlyupregulatedinliverfibrosistissuesandcellsandpositivelycorrelatedwiththedegreeofliverfibrosis.SilencingLnc-MALAT1inhepaticstellatecellssignificantlyinhibitedcellactivationandIL-6expression.Furthermore,Lnc-MALAT1enhancedhepaticstellatecellmigration,proliferation,andcollagensynthesisbyregulatingthebeta-cateninsignalingpathway.

Conclusions:

TheresultsofthisstudysuggestthatexosomalLnc-MALAT1promoteshepaticstellatecellactivationandliverfibrosisthroughthebeta-cateninsignalingpathway.ThisprovidesanewtheoreticalbasisandpotentialtherapeutictargetfortheearlydiagnosisandtreatmentofliverfibrosisInrecentyears,researchontheroleofliverfibrosisintheprogressionofliverdiseasehasincreased.Liverfibrosis,characterizedbythedepositionofextracellularmatrix(ECM)proteins,isapathologicalprocessthatoccursinresponsetochronicliverinjury.Hepaticstellatecells(HSCs)aretheprimaryeffectorcellsresponsiblefortheaccumulationofECMproteinsduringliverfibrosis.Exosomes,extracellularvesiclessecretedbyvariouscelltypes,havebeenshowntoplayacriticalroleinintercellularcommunicationandtheprogressionofliverfibrosis.

Thisstudyfocusedonexploringtheroleofexosomallongnon-codingRNA-Metastasis-associatedlungadenocarcinomatranscript1(Lnc-MALAT1)inHSCactivationandliverfibrosis.TheresultsshowedthatLnc-MALAT1washighlyexpressedinHSC-derivedexosomesisolatedfromplasmaofpatientswithliverfibrosis.Moreover,Lnc-MALAT1wasfoundtopromoteHSCactivation,migration,proliferation,andcollagensynthesis.

TheactivationofHSCsisakeyeventinthedevelopmentofliverfibrosis.Inresponsetochronicliverinjury,HSCsundergoaphenotypicswitchfromaquiescentstatetoanactivatedstate,characterizedbyincreasedproliferationandECMproduction.ThepresentstudydemonstratedthatexosomalLnc-MALAT1promotedHSCactivationbyupregulatingtheexpressionofalpha-smoothmuscleactin(alpha-SMA),amarkerofactivatedHSCs.

Inaddition,Lnc-MALAT1wasfoundtoregulatetheexpressionofinterleukin-6(IL-6)inHSCs.IL-6isapro-inflammatorycytokinethatplaysacrucialroleinthedevelopmentofliverfibrosis.TheupregulationofIL-6expressionbyLnc-MALAT1furtherpromotesHSCactivation.

Furthermore,thestudydemonstratedthatLnc-MALAT1regulatedthebeta-cateninsignalingpathwayinHSCs.Thebeta-cateninpathwayisinvolvedinmanycellularprocesses,includingcellproliferation,migration,andECMproduction.Theactivationofthispathwayhasbeenimplicatedinthedevelopmentofliverfibrosis.Inthepresentstudy,Lnc-MALAT1wasfoundtoenhanceHSCmigration,proliferation,andcollagensynthesisbyactivatingthebeta-cateninpathway.

Inconclusion,thestudyprovidedevidencethatexosomalLnc-MALAT1promotesHSCactivationandliverfibrosisthroughthebeta-cateninsignalingpathway.ThesefindingssuggestthatLnc-MALAT1mightbeapotentialtherapeutictargetforthetreatmentofliverfibrosis.FurtherstudiesareneededtoexplorethedetailedmechanismsunderlyingtheeffectsofLnc-MALAT1onHSCactivationandliverfibrosisLiverfibrosisisacommoncomplicationofchronicliverdiseasessuchashepatitisBandC,alcoholicliverdisease,andnonalcoholicfattyliverdisease.Itoccurswhentheliverisinjuredrepeatedlyorcontinuously,leadingtotheaccumulationofextracellularmatrixproteinsandtheformationofscartissue.Althoughliverfibrosisisareversibleprocessintheearlystages,itcanprogresstocirrhosisandliverfailureifleftuntreated.Therefore,understandingthemolecularmechanismsunderlyingliverfibrosisisessentialfordevelopingeffectivetherapies.

RecentstudieshaveshownthatlongnoncodingRNAs(LncRNAs)areimportantregulatorsofliverfibrosis.LncRNAsareagroupofRNAmoleculesthatarelongerthan200nucleotidesanddonotencodeproteins.Theycanregulategeneexpressionatvariouslevels,includingchromatinmodification,transcription,andposttranscriptionalprocessing.Lnc-MALAT1(metastasis-associatedlungadenocarcinomatranscript1)isawell-knownLncRNAthathasbeenimplicatedinvariousbiologicalprocesses,includingcellproliferation,migration,andinvasion.However,itsroleinliverfibrosishasnotbeenfullyelucidated.

ArecentstudypublishedinthejournalHepatologyinvestigatedtheroleofexosomalLnc-MALAT1intheactivationofhepaticstellatecells(HSCs)andliverfibrosis.HSCsarethemajorcontributorstoliverfibrosis,astheyareresponsibleforproducingextracellularmatrixproteinsandpromotingtheformationofscartissue.ThestudyfoundthatLnc-MALAT1washighlyexpressedinactivatedHSCsandexosomesderivedfromactivatedHSCs.Exosomesaresmallmembrane-boundvesiclesthatcontainvariousbiomolecules,includingRNA,proteins,andlipids.Theycantransfertheircontentstorecipientcellsandmediateintercellularcommunication.

ThestudyfurtherdemonstratedthatexosomalLnc-MALAT1promotedHSCactivationandcollagensynthesisinvitroandinvivo.Specifically,treatmentwithexosomalLnc-MALAT1increasedtheexpressionofalpha-smoothmuscleactin(α-SMA)andcollagenIinHSCs,whicharemarkersofactivatedHSCsandfibrosis.Inmicewithcarbontetrachloride-inducedliverfibrosis,injectionofexosomalLnc-MALAT1aggravatedliverfibrosisandincreasedtheexpressionofα-SMAandcollagenI.Conversely,inhibitionofLnc-MALAT1expressionwithsmallinterferingRNA(siRNA)orantisenseoligonucleotides(ASOs)reducedtheactivationofHSCsandliverfibrosis.

ThestudyalsorevealedthemechanismbywhichexosomalLnc-MALAT1promotesHSCactivationandliverfibrosis.Specifically,Lnc-MALAT1activatesthebeta-cateninsignalingpathway,whichisinvolvedinvariouscellularprocesses,includingcellproliferation,differentiation,andapoptosis.Activationofbeta-cateninpromotesthenucleartranslocationofbeta-cateninandtranscriptionalactivationoftargetgenessuchasCyclinD1andc-Myc.ThestudyshowedthatexosomalLnc-MALAT1increasedthenucleartranslocationofbeta-catenin,aswellastheexpressionofCyclinD1andc-MycinHSCs.M