缺氧环境下白细胞介素8通过Akt-STAT3通路提高骨髓间充质干细胞自噬和增殖能力

Enhancing the ability of autophagy and proliferation of bone marrow mesenchymal stem cells by interleukin-8 through Akt-STAT3 pathway in hypoxic environment

摘要:

探讨缺氧环境下，白细胞介素8 (Interleukin-8, IL-8) 对人骨髓间充质干细胞 (Human bone marrow mesenchymal stem cells，hBMSC) 增殖和自噬能力的影响以及机制。在缺氧模型下，未进行刺激的hBMSC为缺氧对照组；以100 μmol/L 人IL-8蛋白刺激的MSC为IL-8组；若先添加50 μmol/L MK2206 (Akt蛋白抑制剂) 培养30 min，然后再添加100 μmol/L IL-8则为Akt抑制剂组，在正常条件下培养的MSC为正常对照组。利用EdU细胞增殖实验、TUNEL细胞凋亡实验、Western blotting或ELISA等实验分别检测各组MSC细胞EdU标记阳性细胞的数目、细胞凋亡、自噬蛋白 (LC-3) 和Akt/STAT3等蛋白的表达。相对于缺氧对照组和Akt抑制剂组，IL-8明显提高hBMSC增殖和细胞自噬，并降低hBMSC的凋亡率，IL-8组hBMSC的Akt、STAT3和VEGF等蛋白表达增高。结果表明，缺氧环境下，IL-8通过Akt-STAT3通路发挥对MSC的保护作用，对保护MSC抗缺血缺氧性损伤，促进MSC在再生医学中应用具有重要意义。

Abstract:

To study the effects and mechanisms of interleukin-8 (IL-8) on the proliferation and autophagy of human bone marrow mesenchymal stem cells (hBMSC) under hypoxic condition. In the hypoxia model, we set the non-stimulated hBMSC as the hypoxia control group; the hBMSC stimulated by 100 μmol/L human IL-8 as the IL-8 group; the hBMSC stimulated by 50 μmol/L MK2206 (Akt protein inhibitor) and 100μmol/L IL-8 as the Akt inhibitor group; and the normal cultured hBMSC as the normal control group. The experiments of EdU cell proliferation and TUNEL apoptosis were respectively used to detect the number of positive cells that were labeled by EdU and apoptosis in each group, and Western blotting and ELISA were used respectively to detect the expression of autophagy protein (LC-3), Akt/STAT3 and other proteins in each group. The results indicated that the proliferation and autophagy of hBMSC in IL-8 group was higher than that in hypoxia control group and Akt inhibitor group, and the apoptosis rate in IL-8 group decreased. These results and the high expression of Akt, STAT3 and VEGF protein of IL-8 group show that under the hypoxic condition, IL-8 played a protective role on MSC through the Akt-STAT3 pathway. It had important significance in the protection of MSC against the injury due to ischemia and hypoxia, and promoted the application of MSC in regenerative medicine.