转染 miR-26a 的人 CD34 干细胞衍生的外泌体通过促进血管生成和成骨作用预防糖皮质激素诱导的股骨头坏死。

Exosomes derived from human CD34 stem cells transfected with miR-26a prevent glucocorticoid-induced osteonecrosis of the femoral head by promoting angiogenesis and osteogenesis.

机构信息

Department of Orthopedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.

出版信息

Stem Cell Res Ther. 2019 Nov 15;10(1):321. doi: 10.1186/s13287-019-1426-3.

BACKGROUND

Damaged endothelial cells and downregulated osteogenic ability are two key pathogenic mechanisms of glucocorticoid (GC)-induced osteonecrosis of the femoral head (ONFH). Recent studies suggested that transplantation of CD34 stem cell-derived exosomes (CD34-Exos) can treat ischemic diseases by promoting neovascularization and that miR-26a is an important positive regulator of osteogenesis. Moreover, the biological effect of exosomes is closely related to their cargo miRNAs. However, it is not clear whether increasing the abundance of miR-26a in CD34-Exos will inhibit the progress of GC-induced ONFH.

METHODS

MiR-26a was overexpressed in CD34-Exos (miR-26a-CD34-Exos) to increase their osteogenic potential. The angiogenic potential of miR-26a-CD34-Exos was then examined through evaluations of migration and tube-forming capacities in vitro. In addition, in order to observe the osteogenic effect of miR-26a-CD34-Exos on bone marrow stromal cells (BMSCs), Alizarin red staining, alkaline phosphatase (ALP) activity assays, and qPCR were carried out. Finally, miR-26a-CD34-Exos were injected into a GC-induced ONFH rat model to prevent the progress of GC-induced ONFH. The biological effects of miR-26a-CD34-Exos on the ONFH model were evaluated by micro-CT, angiography, and histological staining.

RESULTS

Our data showed that miR-26a-CD34-Exos enhanced human umbilical vein endothelial cell migration and tube-forming capacities. Furthermore, miR-26a-CD34-Exos strengthened the osteogenic differentiation of BMSCs under the influence of GCs in vitro. Finally, the miR-26a-CD34-Exos increased the vessel density and trabecular bone integrity of the femoral head in the GC-induced ONFH rat model, which inhibited the progress of ONFH.

CONCLUSIONS

MiR-26a-CD34-Exos protect the femoral head from damage caused by GCs by strengthening angiogenesis and osteogenesis. The biological effect of miR-26a-CD34-Exos make them suitable for application in the prevention of GC-induced ONFH.

背景

受损的内皮细胞和下调的成骨能力是糖皮质激素（GC）诱导的股骨头坏死（ONFH）的两个关键发病机制。最近的研究表明，CD34 干细胞衍生的外泌体（CD34-Exos）的移植可以通过促进血管新生来治疗缺血性疾病，并且 miR-26a 是成骨的重要正调控因子。此外，外泌体的生物学效应与其携带的 cargo miRNAs 密切相关。然而，增加 CD34-Exos 中 miR-26a 的丰度是否会抑制 GC 诱导的 ONFH 的进展尚不清楚。

方法

通过在 CD34-Exos 中过表达 miR-26a（miR-26a-CD34-Exos）来增加其成骨潜能。然后通过体外迁移和管状形成能力评估来检测 miR-26a-CD34-Exos 的血管生成潜能。此外，为了观察 miR-26a-CD34-Exos 对骨髓基质细胞（BMSCs）的成骨作用，进行了茜素红染色、碱性磷酸酶（ALP）活性测定和 qPCR。最后，将 miR-26a-CD34-Exos 注射到 GC 诱导的 ONFH 大鼠模型中，以防止 GC 诱导的 ONFH 的进展。通过 micro-CT、血管造影和组织学染色评估 miR-26a-CD34-Exos 对 ONFH 模型的生物学效应。

结果

我们的数据表明，miR-26a-CD34-Exos 增强了人脐静脉内皮细胞的迁移和管状形成能力。此外，miR-26a-CD34-Exos 在体外增强了 GCs 影响下 BMSCs 的成骨分化。最后，miR-26a-CD34-Exos 增加了 GC 诱导的 ONFH 大鼠模型中股骨头的血管密度和小梁骨完整性，抑制了 ONFH 的进展。