Duan Wen-Jun, Li Qi-Sheng, Xia Ming-Yu, Tashiro Shin-Ichi, Onodera Satoshi, Ikejima Takashi
China-Japan Research Institute of Medical and Pharmaceutical Sciences, Shenyang Pharmaceutical University, Shenyang, China.
J Asian Nat Prod Res. 2011 Jan;13(1):27-35. doi: 10.1080/10286020.2010.540757.
Our previous results demonstrated that silibinin induced autophagic and apoptotic cell death dependent on reactive oxygen species (ROS especially H(2)O(2) and [image omitted] ) in HT1080 cells. In this study, we further show that p38-NF-κB pathway is involved in silibinin-induced ROS-mediated autophagy. Cells were pretreated with serum-free media for 24 h before being treated with silibinin. Generation of ROS and autophagy was detected in 15 min and 1 h, respectively. Development of autophagy was supported by an upregulated expression of Beclin-1 and conversion of light chain (LC3-I-LC3-II). Expression of p38/p-p38 and transposition of NF-κB from cytoplasm to nuclei were also increased. Inhibitors of p38 and NF-κB and scavengers of H(2)O(2) and O(2)(-) reduced both generation of ROS and simultaneous occurrence of silibinin-induced autophagy. Besides, expression of p38/p-p38 and transposition of NF-κB from cytoplasm to nuclei were decreased by these two ROS scavengers. ROS and p38-NF-κB pathway were possibly cooperated in a positive feedback mechanism. Inhibition of p38, NF-κB, H(2)O(2), or O(2)(-) rescued cells from silibinin-induced death in a long-term (12 h) manner. According to the previous study that silibinin-induced autophagy was a positive regulator of apoptotic cell death, it was possible that ROS and p38-NF-κB mediated silibinin-induced autophagy and eventually led to cell death.
我们之前的研究结果表明，水飞蓟宾在HT1080细胞中诱导自噬性和凋亡性细胞死亡，这依赖于活性氧（ROS，尤其是H₂O₂和[图像省略]）。在本研究中，我们进一步表明p38-NF-κB通路参与了水飞蓟宾诱导的ROS介导的自噬。在用血清饥饿培养基预处理细胞24小时后，再用其处理水飞蓟宾。分别在15分钟和1小时检测ROS的产生和自噬情况。Beclin-1表达上调和轻链（LC3-I-LC3-II）的转化支持了自噬的发生。p38/p-p38的表达以及NF-κB从细胞质向细胞核的转位也增加了。p38和NF-κB的抑制剂以及H₂O₂和O₂⁻的清除剂均减少了ROS的产生以及水飞蓟宾诱导的自噬的同时发生。此外，这两种ROS清除剂降低了p38/p-p38的表达以及NF-κB从细胞质向细胞核的转位。ROS和p38-NF-κB通路可能以正反馈机制协同作用。抑制p38、NF-κB、H₂O₂或O₂⁻能长期（12小时）挽救细胞免于水飞蓟宾诱导的死亡。根据之前的研究，水飞蓟宾诱导的自噬是凋亡性细胞死亡的正调节因子，ROS和p38-NF-κB可能介导了水飞蓟宾诱导的自噬并最终导致细胞死亡。
