Circulating CD34+ Fibroblast Progenitors Participate in Heart Fibrosis of Allografts in Humans and Mice

In this study, we employed single-cell RNA sequencing (scRNA-seq; 10X Genomics platform) combined with genetic lineage tracing in mouse models to comprehensively characterize the non-cardiomyocyte cellular composition of cardiac allografts. Fibrosis is one of the major causes of cardiac allograft malfunction, and is mainly driven by fibroblasts. In this study, we proposed that recipiene derived cells, expecailly CD34+ populations, are an important source of allograft fibroblasts, and play a crucial role in the fibrosis of transplanted hearts. Overall design: Both control and transplanted hearts were enzymatically digested and processed by fluorescence-activated cell sorting (FACS) to isolate viable nucleated target cells. Then the cells were subjected to scRNA-seq analysis.

本研究采用单细胞RNA测序（single-cell RNA sequencing, scRNA-seq；10X Genomics平台）联合小鼠模型中的遗传谱系示踪技术，全面表征心脏同种异体移植物的非心肌细胞组成。纤维化是心脏同种异体移植物功能障碍的主要诱因之一，其病理进程主要由成纤维细胞介导。本研究提出，受体来源的细胞（尤其是CD34+细胞群）是同种异体移植物中成纤维细胞的重要来源，并在移植心脏的纤维化过程中发挥关键作用。实验整体设计：对照组与移植心脏样本均通过酶解法消化，并经荧光激活细胞分选（fluorescence-activated cell sorting, FACS）分离获得存活的有核靶细胞；随后对上述细胞开展scRNA-seq分析。