Construction of miRNA-mRNA network in the differentiation of chicken preadipocytes

1. MicroRNAs (miRNAs) play key roles in regulating lipid metabolism, adipogenesis and fat deposition in chicken. To date, there are only a few miRNAs that have been confirmed to be involved in chicken adipogenesis. The detailed mechanisms by which miRNAs regulate chicken adipogenesis remain largely unknown. 2. To identify candidate miRNAs involved in chicken preadipocyte differentiation and explore potential mechanisms behind their functions, the following study analysed and identified miRNA and mRNA expression levels in undifferentiated and differentiated preadipocytes. Hub miRNA-mRNA interactions were identified, and the degree of connectivity of DE miRNAs in the network was established. 3. A total of 145 DE miRNAs and 660 DE mRNAs were identified between undifferentiated and differentiated preadipocytes. An miRNA-mRNA network was constructed, including 29 DE miRNAs and 155 DE mRNAs, forming 470 miRNA-mRNA interactions. Functional enrichment analysis showed that DE mRNAs in the network were significantly enriched in 712 biological processes and 13 KEGG pathways. Based on the connectivity degree, five DE miRNAs with higher degrees miR-195-x, gga-miR-200a-3p, gga-miR-135a-5p, novel-m0067-5p and novel-m0270-5p were identified as hub miRNAs. Fifty-eight DE mRNAs interacted with these five hub miRNAs and formed 70 miRNA-mRNA interactions. 4. This study constructed a miRNA-mRNA network associated with chicken preadipocyte differentiation and identified five hub miRNAs in the network. The findings identified a number of chicken adipogenic miRNAs and laid the foundation for elucidating the miRNA-mediated regulatory mechanism in chicken adipogenesis.

1. 微小核糖核酸（MicroRNAs，miRNAs）在鸡的脂质代谢、成脂分化与脂肪沉积调控中发挥关键作用。截至目前，仅少数miRNAs被证实参与鸡成脂分化过程，而miRNAs调控鸡成脂分化的具体分子机制仍未被完全阐明。2. 为筛选参与鸡前体脂肪细胞分化的候选miRNAs，并探究其发挥功能的潜在分子机制，本研究对未分化与分化状态的鸡前体脂肪细胞中的miRNA和信使核糖核酸（messenger RNA，mRNA）表达水平进行了分析与鉴定，同时鉴定得到核心miRNA-mRNA互作关系，并明确了差异表达miRNAs（differentially expressed miRNAs，DE miRNAs）在该调控网络中的连接度。3. 本研究在未分化与分化的前体脂肪细胞中共鉴定得到145个DE miRNAs与660个差异表达mRNAs（differentially expressed mRNAs，DE mRNAs）；构建了包含29个DE miRNAs与155个DE mRNAs的miRNA-mRNA调控网络，共计形成470组miRNA-mRNA互作关系。功能富集分析显示，该网络中的DE mRNAs显著富集于712个生物学过程与13条京都基因与基因组百科全书（Kyoto Encyclopedia of Genes and Genomes，KEGG）通路。基于连接度评分，筛选得到5个连接度较高的DE miRNAs：miR-195-x、gga-miR-200a-3p、gga-miR-135a-5p、novel-m0067-5p及novel-m0270-5p，将其定为核心miRNAs；另有58个DE mRNAs与这5个核心miRNAs发生互作，形成70组miRNA-mRNA调控关系。4. 本研究构建了与鸡前体脂肪细胞分化相关的miRNA-mRNA调控网络，并鉴定得到该网络中的5个核心miRNAs。本研究发现了多个鸡成脂相关miRNAs，为阐明miRNA介导的鸡成脂分化调控机制奠定了重要研究基础。