Negative energy balance by feed deprivation affects the adipose miRNome in the lactating goat

One of the main functions of ruminant adipose tissue (AT) is to store lipids for use in productive functions. Body fat mobilization is required during periods of negative energy balance (NEB) such as early lactation or undernutrition. Ruminant nutrition modifies the expression of adipose genes, the regulation of which is not fully understood. The expression of more than 60% of protein-coding genes is post-transcriptionally regulated by microRNAs (miRNAs, small non-coding RNAs, 18 to 25 nucleotides targeting messenger RNAs). Our aim was to characterize miRNA whose expression is regulated by nutrition in the lactating goat AT. Using high-throughput sequencing technology, miRNomes of the lactating AT were established from lactating goats fed a control diet ad libitum and after 48 h of food deprivation (FD) leading to an NEB. MiRNAs sequencing revealed 637 known miRNAs in omental AT of which 16 showed an expression modulated by FD; 14 were upregulated and 2 were downregulated. The network of miRNA-target enrichment identified 2 major miRNAs, miR-223-3p and miR-21-5p which were upregulated by FD and suggested an increase in inflammation of the AT with an NEB obtained after fasting during lactation. The target gene predictions of the differentially expressed miRNAs in AT indicated a significant enrichment in gene ontology functional categories of cell life including apoptosis, cell proliferation, and differentiation as well as in gene expression machinery including regulation of translation and transcription. These data suggest that miRNAs may play a key role in the regulation of AT remodeling.