Medical College of Soochow University, Suzhou 215123, China; National Engineering Laboratory for Modern Silk of Soochow University, Suzhou 215123, China.
Medical College of Soochow University, Suzhou 215123, China.
Chemosphere. 2014 Jun;104:221-7. doi: 10.1016/j.chemosphere.2013.11.030. Epub 2013 Dec 9.
Phoxim is a useful organophosphate (OP) pesticide used in agriculture in China, however, exposure to this pesticide can result in a significant reduction in cocooning in Bombyx mori (B. mori). Titanium dioxide nanoparticles (TiO2 NPs) have been shown to decrease phoxim-induced toxicity in B. mori; however, very little is known about the molecular mechanisms of silk gland damage due to OP exposure and repair of gland damage by TiO2 NP pretreatment. In the present study, exposure to phoxim resulted in a significant reduction in cocooning rate in addition to silk gland damage, whereas TiO2 NP attenuated phoxim-induced gland damage, increased the antioxidant capacity of the gland, and increased cocooning rate in B. mori. Furthermore, digital gene expression data suggested that phoxim exposure led to significant alterations in the expression of 833 genes. In particular, phoxim exposure caused significant down-regulation of Fib-L, Ser2, Ser3, and P25 genes involved in silk protein synthesis, and up-regulation of SFGH, UCH3, and Salhh genes involved in silk protein hydrolysis. A combination of both phoxim and TiO2 NP treatment resulted in marked changes in the expression of 754 genes, while treatment with TiO2 NPs led to significant alterations in the expression of 308 genes. Importantly, pretreatment with TiO2 NPs increased Fib-L, Ser2, Ser3, and P25 expression, and decreased SFGH, UCH3, and Salhh expression in silk protein in the silk gland under phoxim stress. Therefore, Fib-L, Ser2, Ser3, P25, SFGH, UCH3, and Salhh may be potential biomarkers of silk gland toxicity in B. mori caused by phoxim exposure.
辛硫磷是中国农业中一种有用的有机磷（OP）农药，然而，接触这种农药会导致家蚕（B. mori）结茧率显著降低。纳米二氧化钛（TiO2 NPs）已被证明可降低家蚕体内辛硫磷诱导的毒性；然而，对于 OP 暴露导致的丝腺损伤的分子机制以及 TiO2 NP 预处理对丝腺损伤的修复知之甚少。在本研究中，辛硫磷暴露除了导致丝腺损伤外，还显著降低了结茧率，而 TiO2 NP 减轻了辛硫磷诱导的丝腺损伤，提高了丝腺的抗氧化能力，并增加了家蚕的结茧率。此外，数字基因表达数据表明，辛硫磷暴露导致 833 个基因的表达发生显著改变。特别是，辛硫磷暴露导致参与丝蛋白合成的 Fib-L、Ser2、Ser3 和 P25 基因显著下调，而参与丝蛋白水解的 SFGH、UCH3 和 Salhh 基因上调。辛硫磷和 TiO2 NP 联合处理导致 754 个基因的表达发生显著变化，而 TiO2 NP 处理导致 308 个基因的表达发生显著变化。重要的是，TiO2 NP 预处理增加了丝腺中丝蛋白中 Fib-L、Ser2、Ser3 和 P25 的表达，降低了丝腺中 SFGH、UCH3 和 Salhh 的表达。因此，Fib-L、Ser2、Ser3、P25、SFGH、UCH3 和 Salhh 可能是辛硫磷暴露引起家蚕丝腺毒性的潜在生物标志物。
