Cells with Surface Expression of CD133highCD71low are Enriched for Colony-Forming Progenitor Cells in the Adult Murine Pancreas

Previously, we identified tripotent colony-forming progenitor cells in the adult murine pancreas that were capable of self-renewal and differentiation into duct, acinar and endocrine cells in vitro. However, the incidence of these progenitor cells was low (~1% among pancreatic cells in adult 2-4 month-old mice). The goal of the current study was to find cell-surface markers that can distinguish and enrich pancreatic colony-forming progenitor cells. It was found that pancreatic cells could be divided into CD133+CD71- , CD133highCD71low and CD133lowCD71low and CD133-CD71- cells. CD133highCD71low cells, but not other cell populations, were the most enriched for colony-forming progenitors. Interestingly, both CD133+CD71- and CD133highCD71low cells expressed ductal markers as shown by gene expression RT-PCR analysis. To further characterize CD133+CD71- (designated as R1 cells) and CD133highCD71low (designated as R2 cells) ductal cell populations, genome-wide gene expression analysis using RNA-seq was performed. The genes that were differentially expressed by R1 and R2 cells are deposited here. Subsequent pathway analysis of the RNA-seq data revealed that R2 and R1 cells have propensity for cell migration and immune response, respectively. These gene expression analyses suggested ductal cells of the adult pancreas are heterogeneous in nature. Two populations of cells are sorted from the pancreas of adult 2-4 month old C57Bl/6 mice and their RNA profiles are determined. These cell populations are CD133(high)CD71(low) cells (3 samples) and CD133(positive)CD71(negative) (2 samples).既往本团队于成年小鼠胰腺中鉴定出三向集落形成祖细胞（tripotent colony-forming progenitor cells），该类细胞在体外可自我更新，并分化为导管细胞、腺泡细胞与内分泌细胞。然而该类祖细胞的检出率极低，在2-4月龄成年小鼠的胰腺细胞中占比仅约1%。本研究旨在筛选可鉴别并富集胰腺集落形成祖细胞的细胞表面标志物。研究发现胰腺细胞可分为CD133+CD71-、CD133highCD71low、CD133lowCD71low以及CD133-CD71-四个细胞群。其中仅CD133highCD71low细胞群可最大程度富集集落形成祖细胞，其余细胞群均无此效果。有趣的是，经实时荧光定量反转录聚合酶链反应（RT-PCR）基因表达分析证实，CD133+CD71-与CD133highCD71low细胞群均表达导管细胞标志物。为进一步表征CD133+CD71-（命名为R1细胞）与CD133highCD71low（命名为R2细胞）这两个导管细胞群，本研究采用RNA测序（RNA-seq）开展全基因组基因表达分析。R1与R2细胞的差异表达基因已上传至本数据集。后续对RNA-seq数据的通路富集分析显示，R2细胞与R1细胞分别倾向于参与细胞迁移与免疫应答过程。上述基因表达分析结果表明，成年胰腺导管细胞本质上具有异质性。本研究从2-4月龄成年C57Bl/6小鼠胰腺中分选得到两类细胞群，并对其RNA表达谱进行了检测：分别为CD133(high)CD71(low)细胞群（3个样本）与CD133(阳性)CD71(阴性)细胞群（2个样本）。