Department of Orthopedics, Hospital of Chengdu Office of People's Government of Tibetan Autonomous Region, Chengdu, China.
Department of Orthopedics, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, China.
Cartilage. 2022 Apr-Jun;13(2):19476035221077401. doi: 10.1177/19476035221077401.
Stem-cell therapy is a promising treatment for cartilage defects. The newly identified urine-derived stem cells (USCs), which have multipotency and sufficient proliferative ability, are promising candidates for several tissue engineering therapies. In this study, we investigated the role of USC extracellular vehicles (EVs) in promoting the proliferation and migration of chondrocytes.
USCs were characterized by measuring induced multipotent differentiation and flow cytometry analysis of surface marker expression. The EVs were isolated from USCs under normoxic conditions (nor-EVs) and hypoxic conditions (hypo-EVs). Transmission electron microscopy and western blot analysis characterized the EVs. The chondrocytes were cultured in the USC-EVs. CCK-8 assay and EdU staining detected the proliferation of chondrocytes, and transwell assay detected their migration. miR-26a-5p expression in EVs was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The target relationship of miR-26a-5p and phosphatase and tensin homolog (PTEN) was predicted and confirmed. The roles of EVs-miR-26a-5p and PTEN on the proliferation and migration of chondrocytes were also investigated.
Hypo-EVs showed a superior effect in promoting the proliferation and migration of chondrocytes than nor-EVs. Mechanistically, USC-EVs delivered miR-26a-5p into chondrocytes to overexpress miR-26a-5p. PTEN was identified as an miR-26a-5p target in chondrocytes. The effects of EVs-miR-26a-5p on promoting the proliferation and migration of chondrocytes were mediated by its regulation of PTEN.
Our study suggested that hypoxic USC-EVs may represent a promising strategy for osteoarthritis by promoting the proliferation and migration of chondrocytes via miR-26a-5p transfer.
干细胞疗法是治疗软骨缺损的一种有前途的方法。新发现的尿源性干细胞（USCs）具有多能性和足够的增殖能力，是几种组织工程治疗的有前途的候选物。在这项研究中，我们研究了 USCs 细胞外囊泡（EVs）在促进软骨细胞增殖和迁移中的作用。
通过测量诱导多能性分化和表面标志物表达的流式细胞术分析来鉴定 USCs。在常氧条件（nor-EVs）和低氧条件（hypo-EVs）下从 USCs 中分离 EVs。透射电子显微镜和 Western blot 分析鉴定 EVs。将软骨细胞在 USC-EVs 中培养。CCK-8 测定和 EdU 染色检测软骨细胞的增殖，transwell 测定检测其迁移。通过实时定量聚合酶链反应（qRT-PCR）检测 EVs 中的 miR-26a-5p 表达。预测并证实了 miR-26a-5p 与磷酸酶和张力蛋白同源物（PTEN）之间的靶关系。还研究了 EVs-miR-26a-5p 和 PTEN 对软骨细胞增殖和迁移的作用。
Hypo-EVs 促进软骨细胞增殖和迁移的效果优于 nor-EVs。机制上，USC-EVs 将 miR-26a-5p 递送至软骨细胞以过表达 miR-26a-5p。PTEN 被鉴定为软骨细胞中 miR-26a-5p 的靶标。EVs-miR-26a-5p 通过调节 PTEN 促进软骨细胞增殖和迁移的作用。
我们的研究表明，低氧 USC-EVs 通过转移 miR-26a-5p 促进软骨细胞的增殖和迁移，可能代表一种治疗骨关节炎的有前途的策略。
