Deciphering The Role of Progenitor and S tem Cellsin Exocrine Pancreas Regeneration in Zebrafish

Objective: Exocrine pancreas displays an outs tanding capacityfor regeneration and cell fate plas ticity. Using zebrafish modelsfor exocrine cell ablation we previously discovered a novel rarecell population displaying features of immature exocrine pancreascells and identified these cells as a source for tissue regenerationafter virtually complete removal of mature acinar cells.Materials and Methods: To better unders tand this progenitorpool, we now es tablished novel transgenic tools in zebrafish forconditional ablating and for fluorescence-based lineage tracing.Further, FACS (Fluorescence-activated cell sorting) approachesto enrich progenitor cells were es tablished as a requirement forsingle-cell RNA seq s tudies, aiming for a detailed molecularcharacterization of these cells under quiescence and regenerativeconditions.Results: Quantification of sectioned and dissociated healthydouble (ptf۱a: GFP/ela۳l: E۲Crimson) labeled pancreas suggests that the proportion of Ptf۱a+/Ela۳l- progenitor cells reducedfrom ۵% in larva to <۰.۲% in the adult exocrine pancreas.To enable efficient FACS-sorting of these rare cells wees tablished ela۳l:mScarlet ablation line with bright and s tablefluorescence which does not form aggregates and is easier todetect. Moreover, to trace Ptf۱a+ cells during normal pancreasdevelopment and exocrine regeneration, we developed a Cre/lox-based reporter sys tem for genetic cell labeling (ptf۱a: Cre-ERT۲; hsp۷۰: Cytbow). Finally, we es tablished a line for conditionalablation of Ptf۱a+-cells in order to determine if thesecells are the only source for exocrine regeneration.Conclusion: After confirming the exis tence and conservancyof Ptf۱a+ cells even in the adult s tage of zebrafish life, we nowhave all the necessary tools ready to s tudy the molecular identityand role of these progenitor cells in the development andregeneration of the exocrine pancreas of zebrafish

کلیدواژه ها:

Adult S tem Cells ، Exocrine Pancreas ، Regeneration