Solute carrier 25 member 21 (SLC25A21) serves as an oxodicarboxylate carrier, which mainly conveys 2-oxoadipate from the cytoplasm to the mitochondria via a reverse exchange mechanism. Previous studies have indicated that the capacity for glucose consumption is significantly enhanced in 3T3-L1 cells overexpressing SLC25A21. In this study, we upregulate SLC25A21 in 3T3-L1 cells to further probe into the downstream key metabolic genes of SLC25A21. Through high-throughput sequencing combined with bioinformatics analysis, differentially expressed genes are obtained, and the expression of key genes is verified by qRT-PCR. The results demonstrat that: (1) There are 26 up-regulated genes and 66 down-regulated genes in the adipocytes overexpressing SLC25A21; (2) GO (gene ontology) analysis indicates that the biological functions of differentially expressed genes are predominantly involved in lipid synthesis and metabolism, and KEGG (Kyoto encyclopedia of genes and genomes) and GSEA (gene set enrichment analysis) analyses reveal that differentially expressed genes are mainly concentrated in sphingolipid metabolism, secretion and synthesis of insulin and glucagon-like peptide 1; (3) By means of cytoHubba, 10 key genes with the highest scores, such as GRB2, SOS1, SHC1, CBL, HRAS, SOS2, EGFR, MET, PLCG2 and KRAS, were screened out and they are mainly involved in the sugar and lipid metabolism processes of cells; (4) SLC25A21 is overexpressed in adipocytes, and the qRT-PCR verification results show that the mRNA expression levels of other genes increased correspondingly, except for KRAS expression, which exhibits no significant change. These results provide a theoretical basis for further investigations on the role and mechanism of SLC25A21 in the process of glucose and lipid metabolism.
溶质载体家族25成员21 (solute carrier 25 member 21, SLC25A21)是氧代二羧酸盐载体,其主要功能是通过反向交换机制将胞浆内的2-氧代己二酸转运至线粒体。前期研究发现,在过表达SLC25A21的3T3-L1细胞中葡萄糖消耗能力显著增加。为进一步挖掘SLC25A21下游关键代谢基因,本研究在3T3-L1细胞中上调SLC25A21表达,利用高通量测序结合生物信息学分析获得差异表达基因,并通过实时荧光定量聚合酶链式反应(quantitative real-time polymerase chain reaction,qRT-PCR)验证关键基因表达。结果显示:(1)过表达SLC25A21的脂肪细胞中有26个上调基因,66个下调基因;(2)基因本体论(gene ontology, GO)分析表明,差异表达基因的生物学功能主要涉及脂质合成和代谢过程;京都基因和基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)和基因集富集分析(gene set enrichment analysis, GSEA)表明,差异表达基因主要富集在鞘脂代谢、胰岛素和胰高血糖素样肽1分泌和合成等信号通路;(3) CytoHubba筛选出GRB2、SOS1、SHC1、CBL、HRAS、SOS2、EGFR、MET、PLCG2和KRAS等10个评分最高的关键基因,主要参与了细胞的糖、脂代谢过程;(4)在脂肪细胞中过表达SLC25A21,qRT-PCR验证结果表明除KRAS表达无明显变化外,其余基因的mRNA表达水平均出现相应的增高。本研究结果将为今后深入研究SLC25A21在糖、脂代谢过程中的作用及机制提供理论依据。.
Keywords: SLC25A21; bioinformatics; differentially expressed gene; screening and verification.