Division of Parasitology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Box 7036, 750 07, Uppsala, Sweden.
SLU-Global Bioinformatics Centre, Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Box 7023, 750 07, Uppsala, Sweden.
Parasit Vectors. 2020 Jul 9;13(1):342. doi: 10.1186/s13071-020-04212-0.
Parascaris univalens is a pathogenic parasite of foals and yearlings worldwide. In recent years, Parascaris spp. worms have developed resistance to several of the commonly used anthelmintics, though currently the mechanisms behind this development are unknown. The aim of this study was to investigate the transcriptional responses in adult P. univalens worms after in vitro exposure to different concentrations of three anthelmintic drugs, focusing on drug targets and drug metabolising pathways.
Adult worms were collected from the intestines of two foals at slaughter. The foals were naturally infected and had never been treated with anthelmintics. Worms were incubated in cell culture media containing different concentrations of either ivermectin (10 M, 10 M, 10 M), pyrantel citrate (10 M, 10 M, 10 M), thiabendazole (10 M, 10 M, 10 M) or without anthelmintics (control) at 37 °C for 24 h. After incubation, the viability of the worms was assessed and RNA extracted from the anterior region of 36 worms and sequenced on an Illumina NovaSeq 6000 system.
All worms were alive at the end of the incubation but showed varying degrees of viability depending on the drug and concentration used. Differential expression (Padj < 0.05 and log2 fold change ≥ 1 or ≤ - 1) analysis showed similarities and differences in the transcriptional response after exposure to the different drug classes. Candidate genes upregulated or downregulated in drug exposed worms include members of the phase I metabolic pathway short-chain dehydrogenase/reductase superfamily (SDR), flavin containing monooxygenase superfamily (FMO) and cytochrome P450-family (CYP), as well as members of the membrane transporters major facilitator superfamily (MFS) and solute carrier superfamily (SLC). Generally, different targets of the anthelmintics used were found to be upregulated and downregulated in an unspecific pattern after drug exposure, apart from the GABA receptor subunit lgc-37, which was upregulated only in worms exposed to 10 M of ivermectin.
To our knowledge, this is the first time the expression of lgc-37 and members of the FMO, SDR, MFS and SLC superfamilies have been described in P. univalens and future work should be focused on characterising these candidate genes to further explore their potential involvement in drug metabolism and anthelmintic resistance.
Parascaris univalens 是一种全球性的幼驹和周岁马的致病寄生虫。近年来，Parascaris spp. 蠕虫对几种常用驱虫药产生了耐药性，尽管目前尚不清楚这种耐药性产生的机制。本研究的目的是研究成年 P. univalens 蠕虫在体外暴露于三种驱虫药的不同浓度后，其转录反应的变化，重点关注药物靶点和药物代谢途径。
从 2 头屠宰幼驹的肠道中收集成年蠕虫。这些幼驹自然感染，从未使用过驱虫药。将蠕虫在含有不同浓度伊维菌素（10 μM、10 μM、10 μM）、柠檬酸哌嗪（10 μM、10 μM、10 μM）、噻苯达唑（10 μM、10 μM、10 μM）或无驱虫药（对照）的细胞培养基中于 37°C 孵育 24 小时。孵育结束后，评估蠕虫的活力，并从 36 条蠕虫的前区提取 RNA，然后在 Illumina NovaSeq 6000 系统上进行测序。
所有的蠕虫在孵育结束时都存活，但根据使用的药物和浓度，其活力程度有所不同。差异表达（Padj < 0.05 和 log2 倍数变化≥1 或≤-1）分析显示，暴露于不同药物类别后，转录反应存在相似和差异。在药物暴露的蠕虫中上调或下调的候选基因包括 I 期代谢途径短链脱氢酶/还原酶超家族（SDR）、黄素单加氧酶超家族（FMO）和细胞色素 P450 家族（CYP）以及膜转运体主要易化因子超家族（MFS）和溶质载体超家族（SLC）的成员。一般来说，除了仅在暴露于 10 μM 伊维菌素的蠕虫中上调的 GABA 受体亚基 lgc-37 外，不同驱虫药的不同靶标在药物暴露后以非特异性模式被上调和下调。
据我们所知，这是首次在 P. univalens 中描述 lgc-37 和 FMO、SDR、MFS 和 SLC 超家族成员的表达，未来的工作应集中于这些候选基因的特性，以进一步探索它们在药物代谢和驱虫药耐药性中的潜在作用。
