Bian Dan-Dan, Shi Yan-Xia, Shi Kai-Wen, Du Hui-Cong, Tang Bo-Ping, Liu Qiu-Ning
Jiangsu Key Laboratory for Bioresources of Saline Soils, Jiangsu Synthetic Innovation Center for Coastal Bio-Agriculture, Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, School of Wetlands, Yancheng Teachers University, Yancheng 224007, China.
Anhui Key Laboratory of Resource Insect Biology and Innovative Utilization, College of Life Sciences, Anhui Agricultural University, Hefei 230036, China.
Insects. 2025 Jul 7;16(7):699. doi: 10.3390/insects16070699.
, a key lepidopteran model with economic importance, is highly susceptible to environmental heavy metal pollution. This study investigated the mechanisms of Pb toxicity and the associated detoxification and metabolic defense responses in silkworms, employing transcriptome sequencing, enzyme activity assays, and histopathological analysis. Pb exposure caused significant histopathological changes and apoptosis in the fat body, marked by structural disorganization, swollen adipocytes, and degraded extracellular matrix. Molecular analysis showed activation of antioxidant defenses, with superoxide dismutase (SOD) and catalase (CAT) activities significantly elevated ( < 0.05), while peroxidase (POD) activity declined ( < 0.05). Levels of malondialdehyde (MDA) and glutathione (GSH) also decreased. In detoxification responses, carboxylesterase (CarE) activity was reduced, whereas cytochrome P450 (P450) and glutathione S-transferase (GST) activities increased ( < 0.05). Transcriptome sequencing revealed 1,418 differentially expressed genes (DEGs), with notable upregulation of key detoxification genes ( < 0.05), including six cytochrome P450s (CYPs), five uridine diphosphate-glycosyltransferases (UGTs), three glutathione S-transferases (GSTs), and six ATP-binding cassette transporters (ABCs). KEGG enrichment analysis highlighted the involvement of these DEGs in drug metabolism, glutathione metabolism, and ABC transporter pathways ( < 0.05). Functional validation showed that knocking down Cap 'n' Collar C (CncC) significantly suppressed key detoxification genes (, , , , ; < 0.05). qRT-PCR and Western blot analyses confirmed that the Caspase-3 pathway mediates Pb-induced apoptosis, with increased cleaved Caspase-3 and Caspase-4 levels following CncC silencing. Overall, our findings elucidate the mechanisms of Pb toxicity in silkworms and identify as a critical regulator of detoxification and defense against heavy metal stress in lepidopteran insects.
家蚕是一种具有经济重要性的关键鳞翅目模型，对环境重金属污染高度敏感。本研究采用转录组测序、酶活性测定和组织病理学分析，研究了家蚕中铅毒性的机制以及相关的解毒和代谢防御反应。铅暴露导致脂肪体出现显著的组织病理学变化和细胞凋亡，其特征为结构紊乱、脂肪细胞肿胀和细胞外基质降解。分子分析表明抗氧化防御被激活，超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性显著升高（P<0.05），而过氧化物酶（POD）活性下降（P<0.05）。丙二醛（MDA）和谷胱甘肽（GSH）水平也降低。在解毒反应中，羧酸酯酶（CarE）活性降低，而细胞色素P450（P450）和谷胱甘肽S-转移酶（GST）活性增加（P<0.05）。转录组测序揭示了1418个差异表达基因（DEG），关键解毒基因显著上调（P<0.05），包括6种细胞色素P450（CYP）、5种尿苷二磷酸糖基转移酶（UGT）、3种谷胱甘肽S-转移酶（GST）和6种ATP结合盒转运蛋白（ABC）。KEGG富集分析突出了这些DEG参与药物代谢、谷胱甘肽代谢和ABC转运蛋白途径（P<0.05）。功能验证表明，敲低Cap 'n' Collar C（CncC）可显著抑制关键解毒基因（P450、UGT、GST、ABC；P<0.05）。qRT-PCR和蛋白质印迹分析证实，半胱天冬酶-3途径介导铅诱导的细胞凋亡，CncC沉默后裂解的半胱天冬酶-3和半胱天冬酶-4水平升高。总体而言，我们的研究结果阐明了家蚕中铅毒性的机制，并确定CncC是鳞翅目昆虫解毒和抵御重金属胁迫的关键调节因子。
