Metformin-induced alterations in peripheral blood cell trancriptome of healthy individuals

Metformin is a commonly used antihyperglycaemic agent for the treatment of type 2 diabetes. Nevertheless, the exact mechanisms of action, underlying the various therapeutic effects of metformin, remain elusive. The goal of this study was to evaluate the alterations in longitudinal whole-blood transcriptome profiles of healthy individuals after a one-week metformin intervention in order to identify the novel molecular targets and further prompt the discovery of predictive biomarkers of metformin response. Next generation sequencing-based transcriptome analysis revealed four clusters of functionally related genes with a subject-specific differential expression even after a single dose of metformin: ribosomal genes and their pseudogenes (e.g., RNA5-8SN1, RNA5-8SN5, RNY4P10), small nuclear RNAs (e.g., SNORA20, SCARNA5, SNORA80E), genes relevant to insulin production (HNF1B, HNF1A, HNF4A, GCK, INS, NEUROD1, PAX4, PDX1, ABCC8, KCNJ11) and cholesterol homeostasis (APOB, LDLR, PCSK9). After accounting for subject-specific expression, the enrichment of pathways associated with immune responses, such as intestinal immune network for IgA production and cytokine-cytokine receptor interaction were observed for the majority of the cohort. The results of the study reveal for the first time a strong inter-individual variation of the metformin effect on the transcriptional regulation, that goes in line with well-known variability of the therapeutic response to the drug. Overall design: RNA-Seq data of venous blood samples collected from 25 healthy volunteers at three consecutive time points:before administration of metformin, 10 hours after the first does, after 7 days long metformin course.