生酮饮食导致小鼠骨质疏松的转录组学

A transcriptomic study of osteoporosis induced by ketogenic diet in mice

目的通过转录组学分析探讨生酮饮食(KD)导致骨质疏松的分子机制。方法16只8周龄雌性C57BL/6J小鼠分为喂养生酮饲料的KD组和给予普通饲料的正常饮食(Sham)组,喂养3个月。每两周监测体质量、血糖和血酮。采用Micro-CT测量小鼠股骨远端松质骨的骨微结构。提取小鼠骨髓细胞中的RNA,行转录组学检测及生物信息学分析。RT-qPCR验证显著差异基因的表达水平。结果KD弱化小鼠松质骨的骨微结构。与Sham组相比,KD组有165个差异基因(上调91个,下调74个),包括Acot1、Mpig6b、Gp9、Ppbp、Slc2a9等基因。KEGG通路富集分析显示以Apelin信号通路、PI3K-Akt信号通路、ECM受体互作通路的富集程度和差异基因数较高。qPCR结果显示转录组学筛选的5个差异基因在KD组均显著上调,其中Acot1、Mpig6b、Ppbp上调倍数大于2,上调倍数分别为2.49±0.665倍、2.58±0.470倍和2.59±0.611倍,可能与KD导致的骨质疏松相关。结论基于KD小鼠的转录组学分析及RT-qPCR验证表明Acot1、Mpig6b和Ppbp等基因有差异表达。KEGG通路富集分析提示以Apelin信号通路、PI3K-Akt信号通路、ECM受体互作通路的富集程度和差异基因数较高,为研究KD导致骨质疏松的分子机制奠定基础,进而为预防KD导致骨质疏松提供思路。

Objective To investigate the molecular mechanism of osteoporosis caused by ketogenic diet(KD)using transcriptomic analysis.Methods Sixteen 8-week-old female C57BL/6J mice were divided into KD group and sham group for feeding with KD and normal diet for 3 months,respectively.Body weight,blood glucose and blood ketone levels of the mice were measured every two weeks.Microstructure of the cancellous bone in the distal femur was observed with Micro-CT.Total RNA was extracted from bone marrow cells for transcriptomic analysis and bioinformatics analysis.RT-qPCR was used to verify the expression levels of the genes with significant differential expression between the groups.Results KD obviously weakened the microstructure of the cancellous bone in mice.Compared with those in the sham group,the mice in KD group showed 165 differentially expressed genes(91 up-regulated and 74 down-regulated ones),including Acot1,Mpig6b,Gp9,Ppbp,Slc2a9,etc.KEGG pathway enrichment analysis showed obvious enrichment of the Apelin signaling pathway,PI3K-Akt signaling pathway and ECM-receptor interaction signal transduction pathway with greater number of differential genes.RT qPCR results showed that the 5 differential genes screened by transcriptomics were significantly upregulated in KD group,among which Acot1,Mpig6b and Ppbp were upregulated by over two folds(2.49±0.665,2.58±0.470,and 2.59±0.611,respectively),suggesting their involvement in KD-induced osteoporosis.Conclusion The differentially expressed genes and enriched pathways identified in the mouse models provide new clues for studying the molecular mechanism and prevention of KD-induced osteoporosis.