Zhao Jing, Huang Gaofeng, Xu Ting, Yin Daqiang, Bai Jianfeng, Gu Weihua
Shanghai Collaborative Innovation Centre for WEEE Recycling, WEEE Research Centre of Shanghai Polytechnic University, Shanghai 201209, China.
Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Chemosphere. 2017 Aug;180:141-148. doi: 10.1016/j.chemosphere.2017.03.100. Epub 2017 Mar 28.
Caspase proteases play an essential role in cell apoptosis and inflammation, thus matter greatly in animal development and other biological processes. As a ubiquitous environmental pollutant, pentachlorophenol (PCP) is considered to have adverse effects on animal apoptosis during embryonic development, yet the evidence that PCP interfere with caspase genes was seldom reported. To uncover the effects of PCP on caspases expression in early embryos of zebrafish, two concentrations of PCP (5 μg/L and 200 μg/L) were chosen and 14 types of caspase genes at two different developmental stages, 8 h post-fertilization (hpf) and 24 hpf were analyzed. Lower survival and hatching rates, distinct developmental delay and morphological deformities of head and tail were observed. PCP, especially in the high concentration, significantly altered the expressions of most caspase genes. At 8 hpf, PCP had the most significant inductive effects on gene casp8l2 with fold changes (FCs) of 6.87 at 5 μg/L and 4.48 at 200 μg/L, and casp6l1 (with FCs of 3.15/3.69), and inhibitory effects on caspa (with FCs of 0.93/0.53) and caspb (with FCs of 0.99/0.57). At 24 hpf, PCP had the most significant effects on casp6l2, casp9, and caspc. PCP exposure possibly disrupted intrinsic apoptosis pathway considering its effects on casp9 expression. In addition, most caspase genes exhibited higher levels at 24 hpf than 8 hpf except caspc. Our results suggested that PCP had different effects on varied caspase genes, which probably resulting in a profound impact on caspase proteins and apoptosis processes and, ultimately, developmental abnormality.
半胱天冬酶蛋白酶在细胞凋亡和炎症中发挥着至关重要的作用，因此在动物发育和其他生物过程中具有重要意义。作为一种普遍存在的环境污染物，五氯苯酚（PCP）被认为在胚胎发育过程中对动物凋亡有不利影响，但PCP干扰半胱天冬酶基因的证据鲜有报道。为了揭示PCP对斑马鱼早期胚胎中半胱天冬酶表达的影响，选择了两种浓度的PCP（5μg/L和200μg/L），并分析了受精后8小时（hpf）和24 hpf这两个不同发育阶段的14种半胱天冬酶基因。观察到较低的存活率和孵化率、明显的发育延迟以及头部和尾部的形态畸形。PCP，尤其是高浓度的PCP，显著改变了大多数半胱天冬酶基因的表达。在8 hpf时，PCP对基因casp8l2的诱导作用最为显著，5μg/L时的倍数变化（FCs）为6.87，200μg/L时为4.48，对casp6l1（FCs为3.15/3.69）有诱导作用，对caspa（FCs为0.93/0.53）和caspb（FCs为0.99/0.57）有抑制作用。在24 hpf时，PCP对casp6l2、casp9和caspc的影响最为显著。考虑到PCP对casp9表达的影响，PCP暴露可能破坏了内源性凋亡途径。此外，除了caspc外，大多数半胱天冬酶基因在24 hpf时的表达水平高于8 hpf。我们的结果表明，PCP对不同的半胱天冬酶基因有不同的影响，这可能对半胱天冬酶蛋白和凋亡过程产生深远影响，并最终导致发育异常。
