• Citer

About time: functional and molecular effects of prolonged ex vivo human islet culture

par Suleiman, Mara;Bosi, Emanuele;Piron, Anthony ;De Luca, Carmela;Tesi, Marta;Del Guerra, Silvia;Eizirik, Decio L. ;Cnop, Miriam ;Marchetti, Piero;Marselli, Lorella
Référence EASD Annual Meeting of the European Association for the Study of Diabetes(57th: 27 September – 1 October 2021: Virtual meeting), Diabetologia, Vol. 64, page (1-380)
Publication Publié, 2021-10-01

Abstract de conférence

• Accès en ligne
• Détails
• Contenu
• Statistiques

Résumé :

Background and aims: Several studies have addressed human islet features during ex vivo culture under different conditions. It is, however, unclear if and to which extent culture time affects human islet cell functional and molecular traits. Here we studied whether glucose-stimulated insulin secretion (GSIS), insulin content and transcriptome signatures of human islets change upon 8 days of culture after isolation.Materials and methods: Islets were prepared by enzymatic digestion and density gradient purification from 17 non-diabetic organ donors (age: 70±4 years, mean±SEM; BMI: 24±1 Kg/m2; sex: 14F/3M) and cultured in control M199 medium. GSIS, insulin content and RNA-sequencing were studied 2 (D2), 4 (D4) and 8 (D8) days from isolation. Transcriptomes were compared to identify gene expression changes over time.Results: GSIS (n=17), expressed as insulin stimulation index, was similar at D2 (3.5±0.4), D4 (3.1±0.4) and D8 (3.1±0.3). Insulin content was 301.2±28.6 μU/islet at D2, 258.1±35.6 μU/islet at D4 (p=0.13 vs D2) and 205.5±27.4 μU/islet at D8 (p=0.20 vs D4, p<0.01 vs D2 after Tukey’s correction). Gene expression trajectories (n=11) revealed that, at D8 vs D2, 1125 genes were differentially expressed (FDR<0.05, absolute fold-change>2), of which 425 and 770 were respectively up- and down-regulated. The top 5 up- and down-regulated genes were: AC004017.1, PTH2R, NKIRAS2, CTD-3199J23.6, KLHL22; GJC1, ZNF469, WNT5A, COL4A1, CAV1. Gene Set Enrichment Analysis retrieved 40 significant (FDR<0.05) KEGG pathways. Twenty of them were positively enriched (including Fatty Acid Metabolism, Peroxisome and Glycolysis/Gluconeogenesis), and 20 were negatively regulated (including Cell Cycle, ECM receptor interaction, Apoptosis and DNA Replication).Conclusion: In the present study prolonged ex vivo culture of human islets did not significantly affect beta cell insulin responsiveness to glucose stimulation, but reduced insulin content. The respective, associated transcriptomic signatures could unveil some of the molecular mechanisms regulating beta cell function and insulin reservoir, to be possibly surveyed in the study of beta cell resilience or subsidence.