摘要

动物对纳米塑料颗粒的分子反应仍然很不清楚。在这项研究中，我们采用改良的长时间暴露系统来研究秀丽隐杆线虫对纳米聚苯乙烯颗粒的分子反应。暴露于纳米聚苯乙烯颗粒（1μg/ L）显着降低了编码胰岛素受体的daf-2，编码PI3K的age-1和编码Akt / PKB的akt-1的表达，并且增加了编码FOXO转录的daf-16的表达。胰岛素信号通路的因子。在这些基因中，daf-2，age-1或akt-1的突变诱导了对纳米聚苯乙烯颗粒的毒性的抗性，而daf-16的突变诱导了对纳米聚苯乙烯颗粒的毒性的敏感性。 daf-16的RNAi敲低可以进一步抑制daf-2，age-1或akt-1突变体对纳米聚苯乙烯颗粒的毒性的抗性。胰岛素信号传导途径作用于肠细胞以调节纳米聚苯乙烯颗粒的毒性。此外，编码锰超氧化物歧化酶的sod-3，编码金属硫蛋白的mtl-1和编码甘油醛-3-磷酸脱氢酶的gpd-2被鉴定为daf-16的下游靶向基因，用于调节纳米聚苯乙烯颗粒的毒性。因此，响应于线虫中的纳米聚苯乙烯颗粒，鉴定了DAF-2-AGE-1-AKT-1-DAF-16-SOD-3 / MTL-1 / GPD-2的信号传导级联。另外，胰岛素信号传导途径中的这种信号传导级联可以介导线虫对纳米聚苯乙烯颗粒的不利影响的保护性应答。

The molecular response of animals to nanoplastic particles is still largely unclear. In this study, we employed a modified prolonged exposure system to investigate the molecular response of Caenorhabditis elegans to nanopolystyrene particles. Exposure to nanopolystyrene particles (1 μg/L) significantly decreased expressions of daf-2 encoding an insulin receptor, age-1 encoding a PI3K, and akt-1 encoding an Akt/PKB, and increased expression of daf-16 encoding a FOXO transcriptional factor in insulin signaling pathway. Among these genes, mutation of daf-2, age-1, or akt-1 induced a resistance to toxicity of nanopolystyrene particles, whereas mutation of daf-16 induced a susceptibility to the toxicity of nanopolystyrene particles. RNAi knockdown of daf-16 could further suppress the resistance of daf-2, age-1, or akt-1 mutant to the toxicity of nanopolystyrene particles. The insulin signaling pathway acted in intestinal cells to regulate the toxicity of nanopolystyrene particles. Moreover, sod-3 encoding a manganese superoxide dismutase, mtl-1 encoding a metallothionein, and gpd-2 encoding a glyceraldehyde-3-phosphate dehydrogenase were identified as downstream targeted genes for daf-16 in the regulation of toxicity of nanopolystyrene particles. Therefore, a signaling cascade of DAF-2-AGE-1-AKT-1-DAF-16-SOD-3/MTL-1/GPD-2 was identified in response to nanopolystyrene particles in nematodes. Additionally, this signaling cascade in the insulin signaling pathway may mediate a protective response for nematodes against the adverse effects from nanopolystyrene particles.

https://www.ncbi.nlm.nih.gov/pubmed/30729873