Dopamine Transporter SLC6A3 Expression in Langerhans Islets Cells

Objective: The present study was aimed to estimate SLC6A3 expression in the human pancreatic islets cell populations to suggest the putative role of this transporter in insulin secretion by the analysis of public transcriptomic data. Methods: We searched the GEO database for datasets representing the transcriptomes of isolated alpha- and/or beta cells from human pancreatic islets. Then we select genes co-expressed with SLC6A3 by Spearman’s correlation, and examine the identified gene clusters by Gene Ontology enrichment analysis. Results and Discussion: SLC6A3 expression was identified both in alpha- and beta-cells isolated from the human pancreatic islets. Meanwhile, this gene is co-expressed with functionally different gene clusters in distinct cell types. In insulin-producing beta-cells, SLC6A3 is co-expressed with a low number of genes, and this narrow gene cluster is enriched by the genes involved in lipid metabolism and T-cell selection. In contrast, in glucagon-producing alpha-cells, no one Gene Ontology term was significantly overrepresented in SLC6A3 is co-expressed gene cluster. Conclusions: Previously, the production and secretion of dopamine (DA) by islet cells was described. Our data confirm that DA transporter SLC6A3 in expressed in both major cell populations in human pancreatic islets, however the low functional connectivity between genes co-expressed with SLC6A3 is both in alpha- and beta-cells, that suggests that its activity in islets is constitutive and independent from any biologic process.