ABSTRACT
ß-cell proliferation is a rare event in adult pancreatic islets. To study the replication-related ß-cell biology we designed a replicating ß-cells sorting system for gene expression experiments. Replicating ß-cells were identified by EdU incorporation and purified by flow cytometry. For ß-cell separation islet cells were sorted by size, granularity and Newport Green fluorescence emission that was combined with emitted fluorescence for EdU-labelled replicating cells sorting. The purity of the resulting sorted populations was evaluated by insulin staining and EdU for ß-cell identification and for replicating cells, respectively. Total RNA was isolated from purified cell-sorted populations for gene expression analysis. Cell sorting of dispersed islet cells resulted in 96.2% purity for insulin positivity in the collected ß-cell fraction and 100% efficiency of the EdU-based cell separation. RNA integrity was similar between FACS-sorted replicating and quiescent ß-cells. Global transcriptome analysis of replicating vs quiescent ß-cells showed the expected enrichment of categories related to cell division and DNA replication. Indeed, key genes in the spindle check-point were the most upregulated genes in replicating ß-cells. This work provides a method that allows for the isolation of replicating ß-cells, a very scarce population in adult pancreatic islets.
