GSE167589
Integrin avb5 heterodimer is a specific marker of human pancreatic beta cells
The identification of cell surface markers specific to pancreatic beta cells is important for both the study of islet biology and for investigating the pathophysiology of diseases in which this cell type is lost or damaged. Following analysis of publicly available single-cell RNAseq data, we identified specific integrin subunits, integrin av and integrin b5, that were expressed in beta cells. Flow cytometry analysis showed that the vast majority of islet cells expressed some level of both the av and b5 subunits. Using our analysis of single-cell sequencing data as a guide, we isolated populations expressing both subunits from isolated human islets and subjected these to bulk RNAseq analysis. This analysis suggested that the avlob5lo population was enriched for endocrine cell types including alpha, delta and gamma cells, whilst the avhib5hi population was enriched for pericytes and stellate cells . Interestingly, the av+b5neg reference population appeared to be enriched for myeloid cells. This finding was further elaborated using immunofluorescence analysis of histological sections derived from donor human pancreas. Despite the broad expression of specific integrin subunits, we found that expression of integrin avb5 heterodimers was restricted to beta cells and that this complex persisted in islet remnants of some type 1 diabetic individuals from which insulin expression had been lost. This study identifies avb5 heterodimers as a novel cell surface marker of human pancreatic beta cells, a finding that will aid in the identification and characterisation of this important cell type. Overall design: Isolated human pancreatic islets were stained with antibodies against ITGAV and ITGB5 and sorted by FACS using a BD Influx (BD Biosciences) or BD FACSAria Fusion (BD Biosciences). RNA extraction of FACS purified populations was performed using an Isolate II RNA microkit as directed by the manufacturer (Bioline, BIO-65042).