BackgroundH9c2celllineismononucleatedmyoblastderivedfromembryonicrathearttissue.ActivitiesofTGF-β1,MMP-2andMMP-9increaseinH9c2cellsaftertreatmentwithfibrosisstimuli.MicroRNA(miRNA),akindofendogenoussmallnon-codingRNA,participatesincardiacfibrosis.Inthepresentstudy,expressionsoffibrosis-relatedgenesandmicroRNAsinTGF-β1treatedH9c2cellswereinvestigated.MethodsExpressionsoffibrosis-associatedgenes,includingCol3a1,α-SMA,FN1,CTGFandTSP-1,weremeasuredinTGF-β1treatedH9c2cellsbyquantitativereversetranscriptionandPCR(qRTPCR).Levelofα-SMAinH9c2cellswasdemonstratedbyfluorescenceimmunohistochemistry(FIHC)assay.ExpressionsofmaturemiR-16,-21a,-29binH9c2cellsweredeterminedbyqRT-PCRassay.ActivationsofSmad3andNF-kBsignalinginTGF-β1-treatedH9c2cellswerestudiedbydualluciferaseassay.ExpressionsofCol3a1,α-SMA,FN1,CTGFandTSP-1weredetectedinH9c2cellswithadenovirus-mediatedoverexpressionofmiR-21a.ResultsqRT-PCRassayshowedthatα-SMA,FN1,CTGF,TSP-1,butnotCol3a1,wereup-regulatedinTGF-β1treatedH9c2cells.FIHCresultalsorevealedthatα-SMAwasincreasedinTGF-β1-treatedH9c2cells.Consistently,dualluciferaseassayshowedthatSmad3andNF-kBsignalingproteinswereactivatedinTGF-β1-treatedH9c2cells.miR-21a,butnotmiR-16and-29b,wassignificantlyup-regulated.Additionally,over-expressionofmiR-21asignificantlyincreasesmRNAexpressionsofα-SMA,FN1,CTGFandTSP-1inH9c2cells.ConclusionsMiR-21aisup-regulatedinTGF-β1treatedH9c2cells,andmaycontributetoup-regulationsoffibrosis-associatedgenes.
