Identification and functional validation of human islet microRNAs associated with donor trait

Abstract

ObjectivesHuman islets are widely researched to understand pathophysiological mechanisms leading to diabetes. Sex, age, and body mass index (BMI) are key donor traits influencing insulin secretion. Islet function is also regulated by an intricate network of microRNAs. MethodsHere, we profiled 754 microRNAs and 58,190 potential targets in up to 131 different human islet donor preparations (without diabetes) and assessed their association with donor traits. We further performed mechanistical studies to observe the causal role of the age-associated key microRNAs on relative telomere length in human islets. ResultsMicroRNA discovery analyses identified miR-199a-5p and miR-214-3p associated with sex, age and BMI; miR-147b with sex and age; miR-378a-5p with sex and BMI; miR-542-3p, miR-34a-3p, miR-34a-5p, miR-497-5p and miR-99a-5p with age and BMI. There were 959 mRNA transcripts associated with sex (excluding those from sex-chromosomes), 940 with age and 418 with BMI. MicroRNA-199a-5p and miR-214-3p levels inversely associate with transcripts critical in islet function, metabolic regulation, and senescence. Our functional studies verified that inhibition of these two microRNAs (miR-199a-5p/-214-3p) slowed down telomere length shortening in human islet cells maintained in vitro and demonstrating cellular senescence. ConclusionsOur analyses identify human islet cell microRNAs influenced by donor traits. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/512222v2_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@1666c2org.highwire.dtl.DTLVardef@b4695forg.highwire.dtl.DTLVardef@720e99org.highwire.dtl.DTLVardef@1c78ae_HPS_FORMAT_FIGEXP M_FIG C_FIG