Small RNA next-generation sequencing of cardiac fibroblasts isolated from young and old mice

MiRNA expression profile was assessed in cardiac fibroblasts isolated from young (2 months old) and aged (16 months old) mice, by next generation sequencing of small RNA. Bioinformatic analysis of next-generation sequencing output demonstrated 88 differentially expressed miRNAs in aged mice - derived cardiac fibroblasts versus young mice-derived cells, of which two thirds were downregulated and one third were upregulated. The majority of downregulated miRNAs were mapped to chromosome 12, as part of Meg3-Mirg locus, while the remaining were spread on all chromosomes. Almost 90% of miRNA genes within Meg3-Mirg locus were expressed over a wide range in cardiac fibroblasts and had a decreasing trend in the aged group, the majority being significantly downregulated. This study provides evidence that aging is associated to significant alterations in miRNA expression profile in cardiac fibroblasts, a predominant feature being the downregulation of miRNAs within Meg3-Mirg locus. MicroRNA profiles of cardiac fibroblasts isolated from young (2 months old, i.e.reference sample) and old (16-17 months old) C57Bl/6J mice were generated by next-generation sequensing, in 6 biological replicates per each group, using Illumina HiSeq 2500.