Autophagy Prevents Oxidative Stress-Induced Loss of Self-Renewal Capacity and Stemness in Human Tendon Stem Cells by Reducing ROS Accumulation
Autophagy Prevents Oxidative Stress-Induced Loss of Self-Renewal Capacity and Stemness in Human Tendon Stem Cells by Reducing ROS Accumulation
复制标题
自噬通过减少 ROS 积累来防止氧化应激引起的人肌腱干细胞自我更新能力和干性的丧失
DOI：
10.1159/000447916
复制
发表时间：
2016-01-01
影响因子：
--
通讯作者：
Jiang, Chaoyin
中科院分区：
文献类型：
--
作者：
Chen, Hua;Ge, Hong-an;Jiang, Chaoyin
背景/目标：肌腱干细胞具有高度的自我更新能力、多向分化潜能和低免疫原性，有望为肌腱修复和再生提供新的细胞来源。TSC在肌腱损伤部位暴露于增加的氧化应激;然而，TSC如何在氧化应激下保持其干性尚不清楚。方法和结果：在这项研究中，我们发现H2 O2处理增加了人TSCs（hTSCs）中ROS的积累，并导致自我更新能力和干性的丧失，这反映在集落形成和增殖减少，干性标志物Nanog，Oct-4，NS和SSEA-4的表达减少，以及分化能力受损。这些H2 O2诱导的损害被防止预处理与饥饿或雷帕霉素。在H2 O2暴露之前用饥饿或雷帕霉素预处理也导致细胞内和线粒体ROS积累沿着增加的自噬活性，如增加的LC 3切割、Beclin-1表达和GFP-LC 3标记的自噬体形成所示。通过3-MA或CQ或通过Agt-7或Beclin-1的shRNA沉默的自噬抑制降低了饥饿和雷帕霉素对H2 O2处理的hTSCs的保护作用。结论：因此，本研究的发现表明，自噬通过抑制ROS积累来防止氧化应激诱导的hTSCs自我更新能力和干性的丧失。
Background/Aims: Tendon stem cells (TSCs) exhibit a high self-renewal capacity, multi-differentiation potential, and low immunogenicity; thus, these cells might provide a new cell source for tendon repair and regeneration. TSCs are exposed to increased oxidative stress at tendon injury sites; however, how TSCs maintain their stemness under oxidative stress is not clear. Methods and Results: In this study, we found that H2O2 treatment increased ROS accumulation in human TSCs (hTSCs) and resulted in loss of self-renewal capacity and stemness, as reflected in reduced colony formation and proliferation, decreased expression of the stemness markers Nanog, Oct-4, NS, and SSEA-4, and impaired differentiation capability. These H2O2-induced damages were prevented by pretreatment with starvation or rapamycin. Pretreatment with starvation or rapamycin prior to H2O2 exposure also led to decreased intracellular and mitochondrial ROS accumulation along with increased autophagic activity, as manifested in increased LC3 cleavage, Beclin-1 expression, and GFP-LC3-labeled autophagosome formation. Autophagy inhibition by 3-MA or CQ, or by shRNA silencing of Agt-7 or Beclin-1 reduced the protective effects of starvation and rapamycin on H2O2-treated hTSCs. Conclusion: Thus, the findings of this study suggest that autophagy prevents oxidative stress-induced loss of self-renewal capacity and stemness in hTSCs through suppression of ROS accumulation.