Wang Dong, Li Weihang, Ding Ziyi, Shi Quan, Zhang Shilei, Zhang Zhuoru, Liu Zhibin, Wang Xiaocheng, Yan Ming
Department of Orthopedic Surgery, Xijing Hospital, Air Force Medical University, Xi'an, China.
Department of Orthopaedics, Affiliated Hospital of Yanan University, Yanan 716000, China.
Stem Cells Int. 2022 Apr 18;2022:5719077. doi: 10.1155/2022/5719077. eCollection 2022.
This study is aimed at screening the differential expression profiles of mRNA under weightlessness osteoporosis through high-throughput sequencing technology, as well as investigating the pathogenesis of weightlessness osteoporosis at the molecular level especially in bone marrow mesenchymal stem cells (BMSCs).
The mouse bone marrow mesenchymal stem cell line was divided into ground group and simulated microgravity (SMG) group. BMP-2 was used to induce osteogenic differentiation, and SMG group was placed into 2D-gyroscope to simulate weightless condition. Transcriptome sequencing was performed by Illumina technology, DEGs between ground and SMG group was conducted using the DEseq2 algorithm. Molecular functions and signaling pathways enriched by DEGs were then comprehensively analyzed via multiple bioinformatic approaches including but not limited to GO, KEGG, GSEA, and PPI analysis.
A total of 263 DEGs were identified by comparing these 2 groups, including 186 upregulated genes and 77 downregulated genes. GO analysis showed that DEGs were enriched in osteoblasts, osteoclasts cell proliferation, differentiation, and apoptosis; KEGG analysis revealed that DEGs were significantly enriched in the TNF signaling pathway and FoxO signaling pathway; the enrichment results from Reactome database displayed that DEGs were mainly involved in the transcription of Hoxb3 gene, RUNX1 recruitment KMT2A gene, and activation of Hoxa2 chromatin signaling pathway. The four genes, IL6, CXCR4, IGF1, and PLOD2, were identified as hub genes for subsequent analysis.
This study elucidated the significance of 10 hub genes in the development of weightlessness osteoporosis. In addition, the results of this study provide a theoretical basis and novel ideas for the subsequent research of the pathogenesis and clinical treatment of weightlessness osteoporosis.
本研究旨在通过高通量测序技术筛选失重性骨质疏松症下mRNA的差异表达谱，并在分子水平上，特别是在骨髓间充质干细胞（BMSCs）中研究失重性骨质疏松症的发病机制。
将小鼠骨髓间充质干细胞系分为地面对照组和模拟微重力（SMG）组。使用骨形态发生蛋白-2诱导成骨分化，将SMG组置于二维回转器中模拟失重状态。采用Illumina技术进行转录组测序，使用DEseq2算法分析地面对照组和SMG组之间的差异表达基因（DEGs）。然后通过多种生物信息学方法，包括但不限于基因本体论（GO）、京都基因与基因组百科全书（KEGG）、基因集富集分析（GSEA）和蛋白质-蛋白质相互作用（PPI）分析，全面分析DEGs富集的分子功能和信号通路。
通过比较这两组，共鉴定出263个DEGs，其中包括186个上调基因和77个下调基因。GO分析表明，DEGs富集于成骨细胞、破骨细胞的增殖、分化和凋亡；KEGG分析显示，DEGs在肿瘤坏死因子（TNF）信号通路和叉头框蛋白O（FoxO）信号通路中显著富集；Reactome数据库的富集结果显示，DEGs主要参与同源盒基因B3（Hoxb3）的转录、核心结合因子α1（RUNX1）募集赖氨酸甲基转移酶2A（KMT2A）基因以及同源盒基因A2（Hoxa2）染色质信号通路的激活。确定白细胞介素6（IL6）、CXC趋化因子受体4（CXCR4）、胰岛素样生长因子1（IGF1）和赖氨酰氧化酶样蛋白2（PLOD2）这四个基因为后续分析的枢纽基因。
本研究阐明了10个枢纽基因在失重性骨质疏松症发展中的意义。此外，本研究结果为失重性骨质疏松症发病机制及临床治疗的后续研究提供了理论依据和新思路。
