Extracellular vesicles from endothelial progenitor cells prevent steroid-induced osteoporosis by suppressing the ferroptotic pathway in mouse osteoblasts based on bioinformatics evidence
Extracellular vesicles from endothelial progenitor cells prevent steroid-induced osteoporosis by suppressing the ferroptotic pathway in mouse osteoblasts based on bioinformatics evidence
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DOI：
10.1038/s41598-019-52513-x
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发表时间：
2019-11-06
影响因子：
4.6
通讯作者：
Fang, Shiyuan
中科院分区：
文献类型：
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作者：
Lu, Jinsen;Yang, Jiazhao;Fang, Shiyuan
在类固醇性骨质疏松症（SIOP）的发病机制中观察到异常的抗氧化能力。铁凋亡是最近发现的一种细胞死亡类型，其特征在于响应于GPX 4和系统XC-下调而过量产生ROS，其由Fe 2+芬顿反应介导。然而，研究集中在铁下垂和类固醇引起的骨疾病之间的关系仍然有限。本研究采用大剂量地塞米松建立小鼠SIOP模型，并通过显微断层扫描观察骨髓来源的内皮祖细胞（EPC-EVs）提取的细胞外囊泡对SIOP的病理改变有减轻作用（micro-CT），骨体积（BV）、骨表面（BS）、骨小梁厚度升高（Tb.Th）和小梁连接密度（Conn-D）的降低以及小梁分离（Tb.sp）和结构模型指数（SMI）的降低。苏木精-伊红（HE）和Masson染色等组织学分析显示，EPC-EV处理增加了骨小梁和骨髓的体积和密度。RNA测序（RNA-seq）和生物信息学分析揭示了类固醇和EPC-EV治疗后的亚细胞生物学改变。与对照组相比，大剂量地塞米松下调GPX 4和系统XC-，基于京都基因与基因组百科全书（KEGG）的基因集富集分析提示促铁蛋白途径被激活。相比之下，与EPC-EV的联合治疗在基因和mRNA表达水平上部分逆转了KEGG映射的铁蛋白途径的变化。此外，通过RNA-seq进一步证实了铁蛋白标记物表达的改变，如SLC 3A 2、SLC 7A 11和GPX 4。EPC-EV能够逆转地塞米松治疗诱导的半胱氨酸和几种氧化损伤标志物的改变，如丙二醛（MDA）、谷胱甘肽（GSH）和谷胱甘肽二硫化物（GSSG）（通过ELISA检测）。总之，EPC-EV通过抑制成骨细胞中的铁蛋白途径来预防小鼠糖皮质激素诱导的骨质疏松症，这可能为人类SIOP的新疗法提供基础。
Abnormal antioxidative capabilities were observed in the pathogenesis of steroid-induced osteoporosis (SIOP). Ferroptosis is a recently discovered type of cell death that is characterized by the overproduction of ROS in response to GPX4 and system Xc- downregulation, which is mediated by an Fe2+ fenton reaction. However, investigations focusing on the relationship between ferroptosis and steroid-induced bone disease remain limited. In the present study, high-dose dexamethasone was used to establish a mouse SIOP model, and extracellular vesicles extracted from bone marrow-derived endothelial progenitor cells (EPC-EVs) alleviated the pathological changes in SIOP via microtomography (micro-CT), with elevations in bone volume (BV), bone surface (BS), trabecular thickness (Tb.Th), and trabecular connectivity density (Conn-D) and decreases in trabecular separation (Tb.sp) and the structure model index (SMI). Histopathological analysis, such as haematoxylin and eosin (HE) and Masson staining, showed that EPC-EVs treatment increased the volume and density of the trabecular bone and bone marrow. RNA sequencing (RNA-seq) and bioinformatics analysis revealed subcellular biological alterations upon steroid and EPC-EVs treatment. Compared with the control, high-dose dexamethasone downregulated GPX4 and system XC-, and the Kyoto Encyclopedia of Genes and Genomes (KEGG)-based gene set enrichment analysis suggested that the ferroptotic pathway was activated. In contrast, combination treatment with EPC-EVs partly reversed the KEGG-mapped changes in the ferroptotic pathway at both the gene and mRNA expression levels. In addition, alterations in ferroptotic marker expression, such as SLC3A2, SLC7A11, and GPX4, were further confirmed by RNA-seq. EPC-EVs were able to reverse dexamethasone treatment-induced alterations in cysteine and several oxidative injury markers, such as malondialdehyde (MDA), glutathione (GSH), and glutathione disulphide (GSSG) (as detected by ELISA). In conclusion, EPC-EVs prevented mouse glucocorticoid-induced osteoporosis by suppressing the ferroptotic pathway in osteoblasts, which may provide a basis for novel therapies for SIOP in humans.