Department of Orthopedics, Shanghai Punan Hospital of Pudong New District, Shanghai 200125, People's Republic of China.
Biomed Mater. 2023 Feb 16;18(2). doi: 10.1088/1748-605X/acb412.
Steroid-induced avascular necrosis of the femoral head (SANFH) is an intractable orthopedic disease. This study investigated the regulatory effect and molecular mechanism of vascular endothelial cell (VEC)-derived exosomes (Exos) modified with vascular endothelial growth factor (VEGF) in osteogenic and adipogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in SANFH. VECs were culturedand transfected with adenovirus Adv-VEGF plasmids. Exos were extracted and identified.SANFH models were established and treated with VEGF-modified VEC-Exos (VEGF-VEC-Exos). The internalization of Exos by BMSCs, proliferation and osteogenic and adipogenic differentiation of BMSCs were determined by the uptake test, cell counting kit-8 (CCK-8) assay, alizarin red staining, and oil red O staining. Meanwhile, the mRNA level of VEGF, the appearance of the femoral head, and histological analysis were assessed by reverse transcription quantitative polymerase chain reaction and hematoxylin-eosin staining. Moreover, the protein levels of VEGF, osteogenic markers, adipogenic markers, and mitogen-activated protein kinase (MAPK)/extracellular regulated protein kinases (ERK) pathway-related indicators were examined by Western blotting, along with evaluation of the VEGF levels in femur tissues by immunohistochemistry. Glucocorticoid (GC) induced adipogenic differentiation of BMSCs and inhibited osteogenic differentiation. VEGF-VEC-Exos accelerated the osteogenic differentiation of GC-induced BMSCs and inhibited adipogenic differentiation. VEGF-VEC-Exos activated the MAPK/ERK pathway in GC-induced BMSCs. VEGF-VEC-Exos promoted osteoblast differentiation and suppressed adipogenic differentiation of BMSCs by activating the MAPK/ERK pathway. VEGF-VEC-Exos accelerated bone formation and restrained adipogenesis in SANFH rats. VEGF-VEC-Exos carried VEGF into BMSCs and motivated the MAPK/ERK pathway, thereby promoting osteoblast differentiation of BMSCs in SANFH, inhibiting adipogenic differentiation, and alleviating SANFH.
激素诱导性股骨头坏死 (SANFH) 是一种难治性骨科疾病。本研究探讨了血管内皮细胞 (VEC) 衍生的外泌体 (Exos) 修饰的血管内皮生长因子 (VEGF) 在 SANFH 中骨髓间充质干细胞 (BMSCs) 成骨和成脂分化中的调节作用和分子机制。培养 VEC 并转染腺病毒 Adv-VEGF 质粒。提取并鉴定 Exos。建立 SANFH 模型并使用 VEGF 修饰的 VEC-Exos (VEGF-VEC-Exos) 进行治疗。通过摄取试验、细胞计数试剂盒-8 (CCK-8) 测定、茜素红染色和油红 O 染色来测定 Exos 被 BMSCs 内化、BMSCs 增殖和成骨和成脂分化的情况。同时，通过逆转录定量聚合酶链反应和苏木精-伊红染色评估 VEGF、股骨头外观和组织学分析。此外，通过 Western blot 检测 VEGF、成骨标志物、成脂标志物和丝裂原活化蛋白激酶 (MAPK)/细胞外调节蛋白激酶 (ERK) 通路相关指标的蛋白水平，并通过免疫组织化学评估股骨组织中的 VEGF 水平。糖皮质激素 (GC) 诱导 BMSCs 成脂分化并抑制成骨分化。VEGF-VEC-Exos 加速 GC 诱导的 BMSCs 的成骨分化并抑制成脂分化。VEGF-VEC-Exos 激活 GC 诱导的 BMSCs 中的 MAPK/ERK 通路。VEGF-VEC-Exos 通过激活 MAPK/ERK 通路促进 BMSCs 的成骨分化并抑制成脂分化。VEGF-VEC-Exos 加速 SANFH 大鼠的骨形成并抑制脂肪生成。VEGF-VEC-Exos 将 VEGF 带入 BMSCs 并激活 MAPK/ERK 通路，从而促进 SANFH 中 BMSCs 的成骨分化，抑制成脂分化，并缓解 SANFH。
