Intrinsic Features in MicroRNA Transcriptomes Link Porcine Visceral Rather than Subcutaneous Adipose Tissues to Metabolic Risk

Abstract

MicroRNAs (miRNAs) are non-coding small RNA ∼22 nucleotides in length that can regulate the expression of a wide range of coding genes at the post-transcriptional level. Visceral adipose tissues (VATs) and subcutaneous adipose tissues (SATs), the two main fat compartments in mammals, are anatomically, physiologically, metabolically, and clinically distinct. Various studies of adipose tissues have focused mainly on DNA methylation, and mRNA and protein expression, nonetheless little research sheds directly light on the miRNA transcriptome differences between these two distinct adipose tissue types. Here, we present a comprehensive investigation of miRNA transcriptomes across six variant porcine adipose tissues by small RNA-sequencing. We identified 219 known porcine miRNAs, 97 novel miRNA*s, and 124 miRNAs that are conserved to other mammals. A set of universally abundant miRNAs (i.e., miR-148a-3p, miR-143-3p, miR-27b-3p, miR-let-7a-1-5p, and miR-let-7f-5p) across the distinct adipose tissues was found. This set of miRNAs may play important housekeeping roles that are involved in adipogenesis. Clustering analysis indicated significant variations in miRNA expression between the VATs and SATs, and highlighted the role of the greater omentum in responding to potential metabolic risk because of the observed enrichment in this tissue of the immune- and inflammation-related miRNAs, such as the members of miR-17-92 cluster and miR-181 family. Differential expression of the miRNAs between the VATs and SATs, and miRNA target prediction analysis revealed that the VATs-specific enriched miRNAs were associated mainly with immune and inflammation responses. In summary, the differences of miRNA expression between the VATs and SATs revealed some of their intrinsic differences and indicated that the VATs might be closely associated with increased risk of metabolic disorders.

The miR-181d-regulated metalloproteinase Adamts1 enzymatically impairs adipogenesis via ECM remodeling

“…47,48 The TLR/NFκB-related miR-181a decreased in monocytes of obese individuals and is a putative biomarker of metabolic syndrome. 49 Moreover, miR-181a could promote adipogenesis via targeting TNFα, 50 and downregulation of miR-181a could improve hepatic insulin sensitivity by upregulating sirtuin-1.…”

MicroRNA Transfer Between Bone Marrow Adipose and Multiple Myeloma Cells

“…There is evidence of a correlation between the dysregulation of these miRNAs in BMSCs and their dysregulation in myeloma cells [42]. Moreover, these miRNAs are associated with inflammation in WAT, suggesting that their pro-myeloma effects may stem from incriminating involvement with tumor- supportive pathways in BMAT [36, 43]. For example, miR-181a expression negatively correlates with levels of adiponectin[44], the adipokine that is decreased in obesity and has anti-myeloma effects [24].…”

“…The let-7 family is also an important player in adipose tissue development. Universally, adipose tissues contain let-7a-1-5p and let-7f-5p, which are assumed to play a role in adipogenesis [43]. Surprisingly, although let-7a and let-7d are associated with adipose tissue inflammation, let-7a, let-7d, and let-7i are downregulated in the WAT of obese patients [36].…”

A Comprehensive Profile of Mature MicroRNA in the Pig

“…These multiple above-mentioned miRNAs provide insights into the regulation of muscle growth, and are potential candidates for further improvement of meat quality and production using molecular approaches. are subcutaneous adipose tissue-specific enriched miRNAs [64][65][66][67]. Some are specifically expressed in the greater omentum [64,68,69].…”

“…are subcutaneous adipose tissue-specific enriched miRNAs [64][65][66][67]. Some are specifically expressed in the greater omentum [64,68,69]. Research into pig adipose tissue miRNAs may be beneficial in meeting the increasing demand of consumers for improved pork quality, which is a topic of worldwide concern [14].…”