Effect of diet on microRNA expression in ovine subcutaneous and visceral adipose tissues1

Abstract

Knowledge of the molecular mechanisms that regulate ovine adipogenesis is very limited. MicroRNAs (miRNA) have been reported as one of the regulatory mechanisms of adipogenesis. This study aimed to compare the expression of miRNA related to ovine adipogenesis in different adipose depots and to investigate whether their expression is affected by dietary fatty acid composition. We also investigated the role of miRNA in adipogenic gene regulation. Subcutaneous and visceral adipose tissue samples were collected at slaughter from 12 Canadian Arcott lambs fed a barley-based finishing diet where an algae meal (DHA-Gold; Schizochytrium spp.) replaced flax oil and barley grain at 0 or 3% DM (n = 6). Total RNA from each tissue was subjected to quantitative real time (qRT-) PCR analysis to determine the expression of 15 selected miRNA including 11 identified from bovine adipose tissues and 4 conserved between bovine and ovine species. MicroRNAs were differentially expressed according to diet in each tissue depot (miR-142-5p and miR-376d) in visceral and miR-142-5p, miR92a, and miR-378 in subcutaneous adipose tissue; P ≤ 0.05) and in each tissue depot depending on diet (miR-101, miR-106, miR-136, miR-16b, miR-196a-1, miR-2368*, miR-2454, miR-296, miR-376d, miR-378, and miR-92a in both control and DHA-G diets and miR-478 in control; P ≤ 0.05). Six miRNA were subjected to functional analysis and 3 genes of interest (ACSL1, PPARα, and C/EBPα) were validated by qRT-PCR. Both diet and tissue depot affected expression levels of all 3 genes (P < 0.05). miR-101, miR-106, and miR-136 were negatively correlated with their respective predicted gene targets C/ EBPα, PPARα, and ACSL1 in subcutaneous adipose tissue of lambs fed DHA-G. Yet miR-142-5p and miR-101 showed no correlation with ACSL1 or C/EBPα. The variability in expression patterns of miRNA across adipose depots reflects the tissue specific nature of adipogenic regulation. Although the examined miRNA appear to be conserved across ruminant species, our results indicate the presence of ovine specific regulatory mechanisms that can be influenced by diet.

Identification and characterization of differentially expressed miRNAs in subcutaneous adipose between Wagyu and Holstein cattle

“…(2012) and Meale et al . (2014) have also reported that these miRNAs regulate lipogenesis and fat deposition in other animals3637. Taken together, the present study indicates that the higher intramuscular fat level in Wagyu cattle may be partially attributed to these 3 highly expressed miRNAs.…”

Identification of differentially expressed small RNAs and prediction of target genes in Italian Large White pigs with divergent backfat deposition

“…In lambs, miR‐136 was differentially expressed in subcutaneous adipose tissue compared with perirenal fat (Meale et al . ). Guo et al .…”

Differences in Circulating microRNAs between Grazing and Grain-Fed Wagyu Cattle Are Associated with Altered Expression of Intramuscular microRNA, the Potential Target PTEN, and Lipogenic Genes

“…It has been demonstrated that diet and supplementary nutrients affect miRNA expression in adipose tissues of mice [14–16], sheep [17] and cattle [18]. However, miRNAs in circulation and skeletal muscle have poorly understood in farm animals thus far.…”

“…Besides skeletal muscle, transcriptomic miRNA analyses in mammalian adipose tissue have unveiled their roles in fat accumulation. The relevance of miRNAs has also been pronounced in subcutaneous and/or visceral fat accumulation in response to growth and dietary nutrition in mice [14–16], sheep [17], and cattle [18]. When primary cultured porcine adipocytes are exposed to miR-130b-enriched micro-vesicles, peroxisome proliferator-activated receptor γ ( PPARG ) expression is downregulated [19].…”