Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, United Kingdom.
PLoS Negl Trop Dis. 2022 Nov 7;16(11):e0010854. doi: 10.1371/journal.pntd.0010854. eCollection 2022 Nov.
Fasciola spp. liver flukes have significant impacts in veterinary and human medicine. The absence of a vaccine and increasing anthelmintic resistance threaten sustainable control and underscore the need for novel flukicides. Functional genomic approaches underpinned by in vitro culture of juvenile Fasciola hepatica facilitate control target validation in the most pathogenic life stage. Comparative transcriptomics of in vitro and in vivo maintained 21 day old F. hepatica finds that 86% of genes are expressed at similar levels across maintenance treatments suggesting commonality in core biological functioning within these juveniles. Phenotypic comparisons revealed higher cell proliferation and growth rates in the in vivo juveniles compared to their in vitro counterparts. These phenotypic differences were consistent with the upregulation of neoblast-like stem cell and cell-cycle associated genes in in vivo maintained worms. The more rapid growth/development of in vivo juveniles was further evidenced by a switch in cathepsin protease expression profiles, dominated by cathepsin B in in vitro juveniles and by cathepsin L in in vivo juveniles. Coincident with more rapid growth/development was the marked downregulation of both classical and peptidergic neuronal signalling components in in vivo maintained juveniles, supporting a role for the nervous system in regulating liver fluke growth and development. Differences in the miRNA complements of in vivo and in vitro juveniles identified 31 differentially expressed miRNAs, including fhe-let-7a-5p, fhe-mir-124-3p and miRNAs predicted to target Wnt-signalling, which supports a key role for miRNAs in driving the growth/developmental differences in the in vitro and in vivo maintained juvenile liver fluke. Widespread differences in the expression of neuronal genes in juvenile fluke grown in vitro and in vivo expose significant interplay between neuronal signalling and the rate of growth/development, encouraging consideration of neuronal targets in efforts to dysregulate growth/development for parasite control.
片形吸虫属肝吸虫对兽医和人类医学有重大影响。缺乏疫苗和不断增加的驱虫药耐药性威胁着可持续控制，并强调需要新型杀肝吸虫药物。基于体外培养幼年片形吸虫的功能基因组方法有助于在最具致病性的生命阶段验证控制靶标。在体外和体内维持的 21 天龄 F. hepatica 中进行的比较转录组学发现，86%的基因在维持处理中以相似水平表达，这表明这些幼体中核心生物学功能的共性。表型比较显示，与体外对照相比，体内幼体的细胞增殖和生长速度更高。这些表型差异与体内维持的蠕虫中上调类神经干细胞和细胞周期相关基因一致。体内幼体更快的生长/发育通过组织蛋白酶蛋白酶表达谱的转变进一步证明，在体外幼体中以组织蛋白酶 B 为主，在体内幼体中以组织蛋白酶 L 为主。与更快的生长/发育相一致的是，体内维持的幼体中经典和肽能神经元信号成分的显著下调，支持神经系统在调节肝吸虫生长和发育中的作用。体内和体外幼体中 miRNA 成分的差异确定了 31 个差异表达的 miRNA，包括 fhe-let-7a-5p、fhe-mir-124-3p 和预测靶向 Wnt 信号的 miRNA，这支持了 miRNA 在驱动体外和体内维持的幼年肝吸虫生长/发育差异中的关键作用。在体外和体内培养的幼体中神经元基因的广泛表达差异揭示了神经元信号与生长/发育速度之间的显著相互作用，这鼓励考虑神经元靶标，以扰乱生长/发育以进行寄生虫控制。
