A Novel Cre Transgenic Mouse to Label Cardiac Purkinje Fibersduring Ischemic Injury

Purkinje fibers form a network of specializedventricularmyocardial cells to assure a coordinatedpropagation of the electrical impulseduring normalforheartefficientcontractionof the heart.Thedevelopmental origins of Purkinje fibers and their roles during cardiac arrhythmia have been reported.However, theresponse of Purkinje fibers to ischemic injury and theirfunctionrolesduring myocardialregenerationare still illusive. Here we introduceda novel inducibleCreallelemouse linethat specificallylabelsthemousecardiac conduction system. Fate mappingshowed Cre activity in different componentsofindicatedspecific labeling ofthe cardiac conduction system, including the sinoatrial and atrioventricularnodes,as well as the Purkinje fibersdifferentknown and unknowncomponents ofthecardiac conductionsystem. RNA-Seqof laser-captured Purkinje fibers showed a uniqueinjuryresponse occurredafterischemic injuryin thisventricularpart of the conductionsystemand corresponding changes in.Ccellularcompositionchange inofPurkinje fibersafter ischemic injury waswereobserved using immunostaining Laser capture micro-dissection of GFP+ purkinje cells followed by RNA extraction and RNA-seq. For controls, background non-GFP+ cells were used.