Liver miRNA Expression during the Rat Life Span in both Sexes

Global miRNA expression was examined in liver tissues from male and female F344 rats over the life span for the purpose of evaluating their possible roles in susceptibility to liver toxicity and disease. Hepatic miRNA expression was characterized at 2, 5, 6, 8, 15, 21, 52, 78, and 104 weeks of age in both sexes using Agilent 8x15k rat miRNA microarrays containing multiple probes for 677 unique miRNAs. Data processing, 75% normalization, and statistical analysis of microarray data were performed in SAS. Functional analysis (Ingenuity) was performed on select miRNAs exhibiting prominent age and sex expression differences. + Untreated male and female F344 rats from 2, 5, 6, 8, 15, 21, 52, 78, and 104 weeks of age (n=5) were sacrificed by CO2 asphyxiation, whole livers collected and homogenized, total RNA, including small RNA fraction, was used for miRNA expression arrays (Agilent).