Hypoxic preconditioning combined with curcumin promotes cell survival and mitochondrial quality of bone marrow mesenchymal stem cells, and accelerates cutaneous wound healing via PGC-1α/SIRT3/HIF-1α signaling
Hypoxic preconditioning combined with curcumin promotes cell survival and mitochondrial quality of bone marrow mesenchymal stem cells, and accelerates cutaneous wound healing via PGC-1α/SIRT3/HIF-1α signaling
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DOI：
10.1016/j.freeradbiomed.2020.07.023
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发表时间：
2020-11-01
影响因子：
7.4
通讯作者：
Hu，Dahai
中科院分区：
文献类型：
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作者：
Wang，Xujie;Shen，Kuo;Hu，Dahai
骨髓间充质干细胞（BMSCs）迁移后的存活和功能受限是BMSCs介导的组织修复的主要障碍。越来越多的证据表明，低氧预处理可以增强骨髓间充质干细胞移植后的适应性，从而提高其治疗性能。姜黄素是一种天然的膳食产品，已知对各种细胞过程产生深远的保护作用。我们发现，轻度低氧预处理联合姜黄素显著增加了BMSCs的细胞存活率，使更多的细胞富集在G2/M期和S期，并改善了线粒体功能。同时，低氧预处理联合姜黄素改变了BMSCs线粒体嵴的形状，并强烈抑制了线粒体细胞色素的释放，从而抑制了凋亡信号，如减少caspase-3的切割。低氧预处理可通过促进线粒体融合、提高氧化磷酸化（OXPHOS）活性和线粒体复合物Ⅰ酶活性来改善线粒体质量，这与OPA 1、PINK 1和Parkin的表达上调一致。在机制水平上，HIF-1α失稳、PGC-1α和SIRT 3表达上调协同参与了姜黄素联合低氧预处理对BMSCs的保护作用。蛋白酶体抑制剂MG 132稳定HIF-1 α的表达，但不能稳定PGC-1α和SIRT 3的表达，并显著抑制缺氧联合姜黄素条件下BMSCs的存活。MG 132还增加了缺氧与姜黄素处理的BMSC结合时线粒体超氧化物和细胞内过氧化氢（H2 O2）的产生以及caspase-3的活化。此外，通过RNAi敲低SIRT 3和PGC-1α均导致缺氧和姜黄素处理的BMSCs中caspase-3活化。值得注意的是，SIRT 3 RNAi抑制OXPHOS活性，而PGC-1α RNAi在缺氧联合姜黄素处理的BMSCs中触发线粒体超氧化物和细胞内H2 O2的产生。最后，我们在小鼠伤口模型中发现，缺氧联合姜黄素处理的BMSCs加速了皮肤伤口愈合过程。总之，这项研究表明，低氧预处理结合姜黄素可以作为促进BMSC介导的组织修复的有吸引力的策略，并进一步揭示了PGC-1α/SIRT 3/HIF-1α信号转导的丰富库，参与调节线粒体的质量和功能，以适应缺氧。
Restrained survival and function of relocated bone marrow mesenchymal stem cells (BMSCs) is a major impediment to BMSCs-mediated tissue repair. Accumulating evidences have indicated that hypoxic preconditioning of BMSCs could enhance BMSCs’ adaptability after transplantation and thus improve their therapeutic properties. Curcumin, a natural dietary product, is known to exert profound protective effects on various cellular processes. Here we showed that mild hypoxic preconditioning combined with curcumin significantly increased cell survival, enriched more cells in G2/M and S phase, and improved mitochondrial function in BMSCs. Meanwhile, hypoxic preconditioning combined with curcumin altered mitochondrial cristae shape and strongly inhibited mitochondrial cytochromecrelease, which consequently suppressed an apoptosis signal as revealed by reduced caspase-3 cleavage in BMSCs. Moreover, hypoxic preconditioning remarkably promoted mitochondrial quality via increasing mitochondrial fusion and elevating the activity of oxidative phosphorylation (OXPHOS) and mitochondrial complex Ⅰ enzyme in BMSCs, which were in accordance with the up-regulated expression of OPA1, PINK1 and Parkin. At the mechanistic level, the destabilization of HIF-1α and the up-regulated expression of PGC-1α and SIRT3 synergistically contributed to the protective effects of hypoxic preconditioning combined with curcumin in BMSCs. The proteasome inhibitor MG132 stabilized HIF-1a expression, but not PGC-1α or SIRT3, and dramatically restrained BMSCs survival under hypoxia combined with curcumin condition. MG132 also increased mitochondrial superoxide and intracellular hydrogen peroxide (H2O2) production and caspase-3 activation in hypoxia combined with curcumin-treated BMSCs. Furthermore, knockdown of SIRT3 and PGC-1α by RNAi both led to caspase-3 activation in BMSCs after hypoxia and curcumin treatment. Notably, SIRT3 RNAi suppressed OXPHOS activity, while PGC-1α RNAi triggered mitochondrial superoxide and intracellular H2O2production in hypoxia combined with curcumin-treated BMSCs. Finally, we showed that hypoxia combined with curcumin-treated BMSCs accelerated the cutaneous wound healing process in a mice wound model. Overall, this study suggests that hypoxic preconditioning combined with curcumin could serve as an attractive strategy for facilitating BMSCs-mediated tissue repair, and further sheds new light on the rich repertoire of PGC-1α/SIRT3/HIF-1α signaling involved in the regulation of mitochondrial quality and function for cellular adaption to hypoxia.