Department of Orthopedics, The First Affiliated Hospital of Soochow University , Suzhou, Jiangsu Province, China.
Department of Orthopedics, The Ninth People's Hospital of Suzhou , Suzhou, Jiangsu Province, China.
Cell Cycle. 2020 Jul;19(14):1727-1739. doi: 10.1080/15384101.2020.1769301. Epub 2020 Jun 17.
Intervertebral disc degeneration (IDD) is the main cause of lower back pain (LBP), and puzzles massive individuals worldwide. Mesenchymal stem cells (MSCs) transplantation has been demonstrated to potentially ameliorate IDD progression, while the underlying mechanism has not been fully explained. Interleukin-1β (IL-1β) was used to induce nucleus pulposus cells (NPCs) injury. Bone marrow MSCs-derived exosomes were isolated using the super centrifugation method, and characterized using Transmission electron microscopy (TEM) and western blot. Cell viability was determined by MTT, while apoptosis was measured by Annexin-V staining using flow cytometry. miR-142-3fp and gene expressions were measured by real-time PCR. The protein expressions were determined by western blot. Herein, we found exosomes from bone marrow MSCs are circular vesicles, about 80 nm in diameter, and with robust expression of TSG101 and CD63, but without of Calnexin. MSCs exosomes alleviated NPCs apoptosis by reducing IL-1β-induced inflammatory cytokines secretion and MAPK signaling activation. Additionally, MSCs exosomes inhibited NPCs apoptosis and MAPK signaling by delivering miR-142-3p that targets mixed lineage kinase 3 (MLK3). Overexpression of MLK3 abolished the effects of MSCs exosomes on the inflammatory condition, cell apoptosis, and MAPK signaling activation in NPCs. The results confirmed that bone marrow MSCs-derived exosomes-packaged miR-142-3p alleviates NPCs injury through suppressing MAPK signaling by targeting MLK3. The work highlights the therapeutic effect of MSCs on IDD progression, and bone marrow MSCs exosomes might be apromising therapeutic strategy for IDD.
椎间盘退变（IDD）是导致下腰痛（LBP）的主要原因，困扰着全球大量人群。间充质干细胞（MSCs）移植已被证明可能改善 IDD 的进展，但潜在机制尚未完全阐明。本研究采用白细胞介素-1β（IL-1β）诱导髓核细胞（NPCs）损伤。采用超速离心法分离骨髓间充质干细胞来源的外泌体，并通过透射电子显微镜（TEM）和Western blot 进行鉴定。通过 MTT 测定细胞活力，通过流式细胞术用 Annexin-V 染色测定细胞凋亡。通过实时 PCR 测定 miR-142-3fp 和基因表达。通过 Western blot 测定蛋白表达。研究发现，骨髓间充质干细胞来源的外泌体是圆形囊泡，直径约 80nm，具有强烈表达的 TSG101 和 CD63，但没有 Calnexin。MSCs 外泌体通过减少 IL-1β诱导的炎症细胞因子分泌和 MAPK 信号激活来减轻 NPCs 凋亡。此外，MSCs 外泌体通过递送靶向混合谱系激酶 3（MLK3）的 miR-142-3p 抑制 NPCs 凋亡和 MAPK 信号。过表达 MLK3 可消除 MSCs 外泌体对 NPCs 炎症状态、细胞凋亡和 MAPK 信号激活的影响。结果证实，骨髓间充质干细胞来源的外泌体包裹的 miR-142-3p 通过靶向 MLK3 抑制 MAPK 信号来减轻 NPCs 损伤。该研究强调了 MSCs 对 IDD 进展的治疗作用，骨髓间充质干细胞外泌体可能是治疗 IDD 的一种很有前途的治疗策略。
