Presence of immunogenic alternatively spliced insulin gene product in human pancreatic delta cells

• DOI: 10.1007/s00125-023-05882-y
• Publication Date: 2023-03-08T14:02:42Z
• Authors: René van Tienhoven; Maria J. L. Kracht; Arno R. van der Slik; Sofia Thomaidou; Anouk H. G. Wolters; Ben N. G. Giepmans; Juan Pablo Romero...; Michael S. Nelson; Françoise Carlotti; Eelco J. P. de Ko...; Rob C. Hoeben; Arnaud Zaldumbide; Bart O. Roep
• Keywords: Pancreatic Islets

Abstract Aims/hypothesis Transcriptome analyses revealed insulin-gene-derived transcripts in non-beta endocrine islet cells. We studied alternative splicing of human INS mRNA pancreatic islets. Methods Alternative insulin pre-mRNA was determined by PCR analysis performed on RNA and single-cell RNA-seq analysis. Antisera were generated to detect variants tissue using immunohistochemistry, electron microscopy western blot confirm the expression variants. Cytotoxic T lymphocyte (CTL) activation MIP-1β release. Results identified an alternatively spliced product. This variant encodes complete signal peptide B chain C-terminus that largely overlaps with a previously defective ribosomal product . Immunohistochemical translation this -derived splice transcript detectable somatostatin-producing delta cells but not beta cells; confirmed light microscopy. Expression activated preproinsulin-specific CTLs vitro. The exclusive presence may be explained its clearance from insulin-degrading enzyme capturing fragment lack Conclusions/interpretation Our data demonstrate can express derived splicing, containing both diabetogenic chain, their secretory granules. propose play role autoimmunity pathology, as well or paracrine function development destiny, transdifferentiation between promoter activity is confined should used care when assigning cell identity selectivity. Data availability full EM dataset available via www.nanotomy.org (for review: http://www.nanotomy.org/OA/Tienhoven2021SUB/6126-368/ ). Single-cell made Segerstolpe et al [13] found at https://sandberglab.se/pancreas protein sequence INS-splice uploaded GenBank (BankIt2546444 OM489474). Graphical abstract