UVB誘導皮膚成纖維細胞來源的外泌體抑制黑素合成的分子機制研究

UVB誘導皮膚成纖維細胞來源的外泌體抑制黑素合成的分子機制研究摘要：

目的：探討UVB輻射對皮膚成纖維細胞來源外泌體的影響，以及其對黑素合成的調(diào)控機制。

方法：使用流式細胞術(shù)對皮膚成纖維細胞進行分離及分選，利用RNA-Seq技術(shù)研究皮膚成纖維細胞來源的外泌體的轉(zhuǎn)錄組特征，并采用qPCR、Westernblot等手段進一步驗證結(jié)果。同時利用黑素細胞在體外培養(yǎng)系統(tǒng)研究UVB誘導外泌體抑制黑素合成的機制。

結(jié)果：通過RNA-seq發(fā)現(xiàn)，UVB誘導皮膚成纖維細胞來源的外泌體中的一些miRNA與細胞外基質(zhì)組織重塑相關(guān)信號通路有關(guān)。使用qPCR和Westernblot等技術(shù)驗證了miR-34a在外泌體中的表達和對黑素合成的抑制作用。進一步實驗發(fā)現(xiàn)，miR-34a通過直接靶向MITF調(diào)節(jié)其表達，并抑制酪氨酸酶活性，從而降低黑素的合成。

結(jié)論：UVB誘導皮膚成纖維細胞來源的外泌體可以通過miR-34a抑制黑素合成，這一發(fā)現(xiàn)將有助于深入了解皮膚黃色素瘤的病理機制。

關(guān)鍵詞：UVB輻射，皮膚成纖維細胞，來源外泌體，黑素合成，miR-34a。

Title:ThemolecularmechanismunderlyingthesuppressionofmelaninsynthesisbyUVB-inducedfibroblast-derivedexosomes

Abstract:

Objective:ThisstudyaimedtoinvestigatetheeffectofUVBirradiationonfibroblast-derivedexosomesintheskinandtheregulatorymechanismofmelaninsynthesis.

Methods:Fibroblastswereisolatedandsortedbyflowcytometry,andRNA-Seqtechnologywasusedtostudythetranscriptomecharacteristicsoffibroblast-derivedexosomes.qPCR,Westernblot,andothermethodswereusedtovalidatetheresults.Additionally,aninvitroculturesystemofmelanocyteswasusedtoinvestigatethemechanismbywhichUVB-inducedexosomessuppressmelaninsynthesis.

Results:RNA-seqanalysisrevealedthatsomemiRNAsinfibroblast-derivedexosomeswereinvolvedinextracellularmatrixtissueremodeling-associatedsignalingpathways.FurtherexperimentsverifiedtheexpressionofmiR-34ainexosomesanditsinhibitoryeffectonmelaninsynthesis.ItwasfoundthatmiR-34adirectlytargetsMITFtoregulateitsexpressionandinhibitstyrosinaseactivity,therebyreducingmelaninsynthesis.

Conclusion:UVB-inducedfibroblast-derivedexosomescansuppressmelaninsynthesisthroughmiR-34a,whichwillhelpfurtherunderstandthepathogenesisofmelanoma.

Keywords:UVBirradiation,fibroblasts,exosomes,melaninsynthesis,miR-34aMelanomaisamalignanttumorthatoriginatesfrommelanocytes,whichareresponsiblefortheproductionofmelanin.Theexcessivesynthesisofmelanincanleadtohyperpigmentation,whichisacommonskindisorder.UVBirradiationisknowntoinducechangesinskinbiology,includingincreasedmelaninsynthesis.Therefore,itisimportanttounderstandthemechanismsofmelaninsynthesisandtheeffectsofUVBirradiationonskinbiology.

Exosomesaresmallmembrane-boundvesiclesthataresecretedbyvariouscelltypes,includingfibroblasts.RecentstudieshaveshownthatexosomescantransfermicroRNAs(miRNAs)torecipientcellsandregulatetheirbiologicalfunctions.Inthisstudy,UVB-inducedfibroblast-derivedexosomeswereinvestigatedfortheireffectsonmelaninsynthesis.

TheresultsshowedthatUVBirradiationoffibroblastsincreasedthesecretionofexosomes,whichcontainedmiR-34a.FurtherexperimentsdemonstratedthatmiR-34adirectlytargetedthetranscriptionfactorMITF,whichisakeyregulatorofmelaninsynthesis.Inaddition,miR-34awasfoundtoinhibittheactivityoftyrosinase,acriticalenzymeinmelaninsynthesis.

ThesefindingssuggestthatUVB-inducedfibroblast-derivedexosomescansuppressmelaninsynthesisthroughthetransferofmiR-34a.Thisprovidesnewinsightsintotheregulationofmelaninsynthesisandthepathogenesisofmelanoma.FurtherstudiesareneededtoelucidatethemechanismsunderlyingtheeffectsofexosomesandmiRNAsonskinbiologyandtoexploretheirpotentialastherapeutictargetsforskindisordersInadditiontosuppressingmelaninsynthesis,exosomeshavealsobeenshowntoplayaroleinregulatingotherskinfunctions,suchaswoundhealingandimmuneresponses.Forexample,fibroblast-derivedexosomeshavebeenshowntopromotethemigrationandproliferationofkeratinocytes,whichareessentialforwoundhealing(Bianetal.,2019).Furthermore,exosomesreleasedbyimmunecells,suchasdendriticcellsandmacrophages,canmodulatetheactivityofotherimmunecellsandpromotetissuerepair(Khanetal.,2015;Zhangetal.,2020).

Theroleofexosomesinskinbiologyandpathologyisstillnotfullyunderstood,andmoreresearchisneededtoelucidatetheirfunctionsandmechanismsofaction.However,thegrowingbodyofevidencesuggeststhatexosomesandtheircargo,includingmiRNAs,couldbepotentialtargetsforthetreatmentofskindisorders,suchasmelanoma,psoriasis,andatopicdermatitis.Advancementsinexosomeisolationandcharacterizationtechniques,aswellasthedevelopmentofengineeredexosomeswithtargetedcargo,holdpromiseforthedevelopmentofnoveltherapiesfortheseconditions.

Inconclusion,exosomesareemergingasimportantregulatorsofskinbiologyandpathology,throughtheirabilitytotransferbioactivemolecules,suchasmiRNAs,betweencells.TheidentificationofspecificexosomalmiRNAsandtheirtargetsprovidesnewinsightsintothecomplexmechanismsunderlyingskinfunctionanddisease.FurtherresearchisneededtofullyunderstandtheroleofexosomesinskinbiologyandpathologyandtoexploittheirpotentialastherapeutictargetsforskindisordersExosomesaresmallextracellularvesiclesthataresecretedbyavarietyofcells,includingskincells.Theycontainacomplexcargoofbiomolecules,includingproteins,lipids,andnucleicacids,suchasmicroRNAs(miRNAs).miRNAsaresmall,non-codingRNAsthatplayimportantrolesinpost-transcriptionalgeneregulationbybindingtothe3'-untranslatedregion(3'-UTR)oftargetmessengerRNAs(mRNAs),resultingintheirdegradationortranslationalrepression.ExosomalmiRNAshavebeenshowntoplayimportantrolesinmanybiologicalprocesses,includingimmunity,inflammation,andcancer,andareemergingaskeyregulatorsofskinbiologyandpathology.

Skinisthelargestorganinthehumanbodyandplaysacriticalroleinregulatingbodytemperature,protectingagainstphysicalandchemicaldamage,andservingasabarrieragainsttheoutsideenvironment.Skinalsocontainsacomplexnetworkofdifferentcelltypes,includingkeratinocytes,fibroblasts,melanocytes,andimmunecells,whichcommunicatethroughvarioussignalingpathwaystoensureproperskinfunction.Disturbancesinthesepathwayscanleadtoavarietyofskindisorders,suchaspsoriasis,atopicdermatitis,andskincancer.

ExosomeshavebeenshowntoplayimportantrolesinskinbiologyandpathologybytransferringmiRNAsandotherbiomoleculesbetweendifferentskincelltypes.Forexample,onestudyhasshownthatexosomesderiv