Comprehensive metabolomic profiling of Angiostrongylus cantonensis across its life cycle reveals developmental and host-associated metabolic signatures.

BACKGROUND: Angiostrongylus cantonensis is a zoonotic nematode that causes eosinophilic meningitis in humans. Although its life cycle encompasses multiple developmental stages and hosts, the metabolic changes underlying its development and host interactions remain poorly understood. This study aimed to characterize the dynamic metabolomic profiles of A. cantonensis across its entire life cycle and to identify metabolic signatures associated with development and different host environments.

METHODS: Untargeted metabolomics using liquid chromatography-mass spectrometry was performed on five key life cycle stages of A. cantonensis: first-stage larvae, third-stage larvae (L3), mouse-derived and rat-derived fourth-stage larvae (L4), fifth-stage larvae, and female and male adults. Multivariate statistical analyses, including principal component analysis, partial least squares-discriminatory analysis, and orthogonal partial least squares-discriminatory analysis, were employed alongside univariate tests, random forest (RF) modeling, and pathway enrichment analysis to detect differential metabolites and key pathways.

RESULTS: A total of 4517 and 2613 ion features were detected in positive and negative electrospray ionization modes, respectively. Metabolic profiles shifted markedly, especially during the L3-to-L4 transition, with over 2000 differentially regulated features (P < 0.05). A total of 127 unique putatively annotated compounds were identified, including fatty acyls, purine nucleosides, and steroids, among others. Putative metabolites such as hypoxanthine, inosine, and prostaglandins were upregulated at the fourth larval stage, whereas xanthosine peaked in female adults (P < 0.05). RF models identified daidzin and docosapentaenoic acid as key discriminators between L3 and L4, and 4-phenylbutyric acid as a discriminator between rat-derived and mouse-derived L4. Pathway analysis revealed that vitamin B6 metabolism, thiamine metabolism, and nicotinate and nicotinamide metabolism were significantly altered during L3-to-L4 transition and were also host-associated (P < 0.01).

CONCLUSIONS: This comprehensive metabolomic analysis of A. cantonensis provides a detailed map of its metabolic landscape across the life cycle. The findings reveal profound metabolic reprogramming during parasite establishment in the definitive host and identify host-associated metabolic signatures. The key putatively annotated compounds and pathways offer new insights into parasite biology, host-parasite interactions, and potential targets for diagnostics and therapeutics against angiostrongyliasis. Importantly, the functional interpretations presented herein are hypothesis-generating and require experimental validation through targeted functional studies.