Quantitative lipidomic analysis of Ascaris suum

Abstract

Ascaris is a soil-transmitted nematode that causes ascariasis, a neglected tropical disease affecting predominantly children and adolescents in the tropics and subtropics. Approximately 0.8 billion people are affected worldwide, equating to 0.86 million disability-adjusted life-years (DALYs). Exploring the molecular biology of Ascaris is important to gain a better understanding of the host-parasite interactions and disease processes, and supports the development of novel interventions. Although advances have been made in the genomics, transcriptomics and proteomics of Ascaris, its lipidome has received very limited attention. Lipidomics is an important sub-discipline of systems biology, focused on exploring lipids profiles in tissues and cells, and elucidating their biological and metabolic roles. Here, we characterised the lipidomes of key developmental stages and organ systems of Ascaris of porcine origin via high throughput LC-MS/MS. In total, > 500 lipid species belonging to 18 lipid classes within three lipid categories were identified and quantified–in precise molar amounts in relation to the dry weight of worm material–in different developmental stages/sexes and organ systems. The results showed substantial differences in the composition and abundance of lipids with key roles in cellular processes and functions (e.g. energy storage regulation and membrane structure) among distinct stages and among organ systems, likely reflecting differing demands for lipids, depending on stage of growth and development as well as the need to adapt to constantly changing environments within and outside of the host animal. This work provides the first step toward understanding the biology of lipids in Ascaris, with possibilities to work toward designing new interventions against ascariasis.

Metabolomics and lipidomics studies of parasitic helminths: molecular diversity and identification levels achieved by using different characterisation tools

“…In S. mansoni , Ferreira et al ( 2014a ) reported the presence of phospholipids and triacylglycerols, with phosphatidylcholines (PCs) being the major lipids (Ferreira et al, 2015 ). Similarly, Wang et al ( 2020 ) putatively identified 587 lipids from the somatic tissue extract of Ascaris suum .…”

“…Over 500 putative metabolites, including lipids, have been reported from a single helminth species (Wang et al, 2018 , 2020 ; Wangchuk et al, 2019b ; Yeshi et al, 2020 ), yet their bioactivity remains largely unexplored. Currently, only 20–30% of the total metabolites are known, with 70–80% remaining unidentified due to limitations in identification protocols and helminth-specific compound libraries.…”

Helminth lipidomics: Technical aspects and future prospects

“…(2016) Ascaris suum Female adult UHPLC-MS/MS Targeted lipidomics (steroids) Ma et al. (2019a) L3-egg, L3-lung, L4, male and female adults, as well as organ system from male and female adults UHPLC-MS/MS Untargeted lipidomics Wang et al. (2020d) Haemonchus contortus L3, L4, adults UHPLC-MS/MS Untargeted lipidomics Wang et al.…”

“…Recently, we also investigated the lipidomes of key developmental stages/sexes as well as organ systems of A. suum using high throughput LC-MS/MS ( Wang et al., 2020d ). Approximately 600 lipid species belonging to 18 lipid classes were identified.…”

“…PC(17:0/17:0) are not suitable for lipidomic studies of worms. As we have shown recently ( Wang et al., 2020d ), lipid standards comprising isotope-labelled analogues can offer a solution for quantitative analyses of worm lipids, but there is still a need for specific standards, such as dafachronic acids, to serve as proxy for the precise characterisation of worm specific lipids of biological importance (cf. Ma et al., 2019a ; Ma et al., 2019c ).…”