Fluorescein-based sensors to purify human α-cells for functional and transcriptomic analyses

Pancreatic -cells secrete glucagon, an insulin counter-regulatory peptide hormone critical for the maintenance of glucose homeostasis. Investigation of the function of human -cells remains a challenge due to the lack of cost-effective purification methods to isolate high-quality -cells from islets. Here, we use the reaction-based probe diacetylated Zinpyr1 (DA-ZP1) to introduce a novel and simple method for enriching live -cells from dissociated human islet cells with > 97% purity. The -cells, confirmed by sorting and immunostaining for glucagon, were cultured up to 10 days to form -pseudoislets. The -pseudoislets could be maintained in culture without significant loss of viability, and responded to glucose challenge by secreting appropriate levels of glucagon. RNA-sequencing analyses (RNA-seq) revealed that expression levels of key -cell identity genes were sustained in culture while some of the genes such as DLK1, GSN, SMIM24 were altered in -pseudoislets in a time-dependent manner. In conclusion, we report a method to sort human primary -cells with high purity that can be used for downstream analyses such as functional and transcriptional studies.