脊髓缺血再灌注损伤(SCIRI)通常导致神经损伤和死亡。在这方面,了解SCIRI的病理和预防其发展具有重要的临床价值。
这里,我们分析了骨髓间充质干细胞(BMMSC)来源的外泌体microRNA(miR)-124-3p在SCIRI中的作用。建立SCIRI大鼠模型,和Ern1和M2巨噬细胞极化标记(Arg1,Ym1和Fizz)的表达使用免疫组织化学测定,免疫荧光测定,RT-qPCR,和蛋白质印迹分析。使用生物信息学分析预测miR-124-3p和Ern1之间的靶向关系,并通过双荧光素酶报告基因测定进行验证。巨噬细胞与含有miR-124-3p的BMMSC衍生的外泌体共培养。使用流式细胞术鉴定M2巨噬细胞,并测定Arg1、Ym1和Fizz的表达。此外,SCIRI大鼠注射含有miR-124-3p的外泌体,用TUNEL法观察脊髓细胞凋亡,用H&E染色评价病理情况。
在SCIRI中,Ern1高表达,M2极化标记表达较差。沉默Ern1导致M2极化标记的表达升高。MiR-124-3p靶向并负调控Ern1。外泌体miR-124-3p增强M2极化。高表达的外泌体miR-124-3p阻碍细胞凋亡并减轻SCIRI诱导的组织损伤和神经损伤。来自BMMSC来源的外泌体的miR-124-3p通过抑制Ern1和促进M2极化改善SCIRI及其相关神经损伤。
总之,来自BMMSCs的外泌体miR-124-3p通过调节Ern1和M2巨噬细胞极化减轻SCIRI诱导的神经损伤。
Spinal cord ischemia-reperfusion injury (SCIRI) often leads to neurological damage and mortality. In this regard, understanding the pathology of SCIRI and preventing its development are of great clinic value.
Herein, we analyzed the role of bone marrow mesenchymal stem cell (BMMSC)-derived exosomal microRNA (miR)-124-3p in SCIRI. A SCIRI rat model was established, and the expression of
Ern1 and M2 macrophage polarization markers (Arg1, Ym1, and Fizz) was determined using immunohistochemistry, immunofluorescence assay, RT-qPCR, and western blot analysis. Targeting relationship between miR-124-3p and
Ern1 was predicted using bioinformatic analysis and verified by dual-luciferase reporter assay. Macrophages were co-cultured with miR-124-3p-containing BMMSC-derived exosomes. M2 macrophages were identified using flow cytometry, and the expression of Arg1, Ym1, and Fizz was determined. In addition, SCIRI rats were injected with miR-124-3p-containing exosomes, spinal cord cell apoptosis was observed using TUNEL assay, and the pathological condition was evaluated with H&E staining.
In SCIRI,
Ern1 was highly expressed and M2 polarization markers were poorly expressed. Silencing
Ern1 led to elevated expression of M2 polarization markers. MiR-124-3p targeted and negatively regulated
Ern1. Exosomal miR-124-3p enhanced M2 polarization. Highly expressed exosomal miR-124-3p impeded cell apoptosis and attenuated SCIRI-induced tissue impairment and nerve injury. miR-124-3p from BMMSC-derived exosomes ameliorated SCIRI and its associated nerve injury through inhibiting Ern1 and promoting M2 polarization.
In summary, exosomal miR-124-3p derived from BMMSCs attenuated nerve injury induced by SCIRI by regulating Ern1 and M2 macrophage polarization.