Jo Hyo Sang, Yeo Eun Ji, Shin Min Jea, Choi Yeon Joo, Yeo Hyeon Ji, Cho Su Bin, Park Jung Hwan, Lee Chi Hern, Eum Won Sik, Choi Soo Young
Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon, 24252, Korea.
Biotechnol Lett. 2017 Apr;39(4):511-521. doi: 10.1007/s10529-017-2286-5. Epub 2017 Jan 10.
To identify the protective effect of DJ-1 protein against oxidative stress-induced HepG2 cell death, we used cell-permeable wild type (WT) and a mutant (C106A Tat-DJ-1) protein.
By using western blotting and fluorescence microscopy, we observed WT and C106A Tat-DJ-1 proteins were efficiently transduced into HepG2 cells. Transduced WT Tat-DJ-1 proteins increased cell survival and protected against DNA fragmentation and intracellular ROS generation levels in HO-exposed HepG2 cells. At the same time, transduced WT Tat-DJ-1 protein significantly inhibited NF-κB and MAPK (JNK and p38) activation as well as regulated the Bcl-2 and Bax expression levels. However, C106A Tat-DJ-1 protein did not show any protective effect against cell death responses in HO-exposed HepG2 cells.
Oxidative stress-induced HepG2 cell death was significantly reduced by transduced WT Tat-DJ-1 protein, not by C106A Tat-DJ-1 protein. Thus, transduction of WT Tat-DJ-1 protein could be a novel strategy for promoting cell survival in situations of oxidative stress-induced HepG2 cell death.
为了确定DJ-1蛋白对氧化应激诱导的HepG2细胞死亡的保护作用，我们使用了可穿透细胞的野生型（WT）和突变型（C106A Tat-DJ-1）蛋白。
通过蛋白质免疫印迹法和荧光显微镜观察，我们发现WT和C106A Tat-DJ-1蛋白均能有效地转导进入HepG2细胞。转导的WT Tat-DJ-1蛋白可提高细胞存活率，并保护HepG2细胞免受过氧化氢（HO）暴露诱导的DNA片段化和细胞内活性氧（ROS）生成水平升高的影响。同时，转导的WT Tat-DJ-1蛋白可显著抑制核因子κB（NF-κB）和丝裂原活化蛋白激酶（MAPK，包括c-Jun氨基末端激酶（JNK）和p38）的激活，并调节Bcl-2和Bax的表达水平。然而，C106A Tat-DJ-1蛋白对HO暴露的HepG2细胞的细胞死亡反应未显示出任何保护作用。
转导的WT Tat-DJ-1蛋白可显著降低氧化应激诱导的HepG2细胞死亡，而C106A Tat-DJ-1蛋白则不能。因此，转导WT Tat-DJ-1蛋白可能是在氧化应激诱导的HepG2细胞死亡情况下促进细胞存活的一种新策略。
