Transcriptome analysis reveals molecular anthelmintic effects of procyanidins in C. elegans

• Published in: PloS one 2017-09, Vol.12 (9), p.e0184656
• Main Authors: Spiegler, Verena, Hensel, Andreas, Seggewiß, Jochen, Lubisch, Milena, Liebau, Eva
• Format: Article
• Language: English
• Subjects: Animals; Anthelmintic agents; Anthelmintics - isolation & purification; Anthelmintics - pharmacology; Binding sites; Biology; Biology and Life Sciences; Caenorhabditis elegans; Caenorhabditis elegans - drug effects; Caenorhabditis elegans - genetics; Caenorhabditis elegans - metabolism; Caenorhabditis elegans Proteins - genetics; Caenorhabditis elegans Proteins - metabolism; Cellular structure; Ceramium mucronatum; Combretum - chemistry; Combretum - metabolism; Down-Regulation - drug effects; Flavonoids; Gene expression; Gene Expression Profiling; Genes; Genes, Reporter; Helminthiasis; Immune response; Immune system; Innate immunity; Intestine; Leaves; Livestock; Medical research; Medicine and Health Sciences; Membranes; Microscopy, Fluorescence; Mode of action; Nematodes; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Pharmaceuticals; Physiology; Plant extracts; Plant Extracts - chemistry; Plant Leaves - chemistry; Plant Leaves - metabolism; Polyphenols; Proanthocyanidins; Proanthocyanidins - isolation & purification; Proanthocyanidins - pharmacology; Procyanidins; Proline; Proteins; Real-Time Polymerase Chain Reaction; Reporter gene; Research and Analysis Methods; RNA - isolation & purification; RNA - metabolism; Salivary Proline-Rich Proteins - genetics; Salivary Proline-Rich Proteins - metabolism; Structural proteins; Studies; Tannins; Target recognition; Up-Regulation - drug effects; Veterinary medicine
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0184656

Worldwide, more than 1 billion people are affected by infestations with soil-transmitted helminths and also in veterinary medicine helminthiases are a severe threat to livestock due to emerging resistances against the common anthelmintics. Proanthocyanidins have been increasingly investigated for their anthelmintic properties, however, except for an interaction with certain proteins of the nematodes, not much is known about their mode of action. To investigate the anthelmintic activity on a molecular level, a transcriptome analysis was performed in Caenorhabditis elegans after treatment with purified and fully characterized oligomeric procyanidins (OPC). The OPCs had previously been obtained from a hydro-ethanolic (1:1) extract from the leaves of Combretum mucronatum, a plant which is traditionally used in West Africa for the treatment of helminthiasis, therefore, also the crude extract was included in the study. Significant changes in differential gene expression were observed mainly for proteins related to the intestine, many of which were located extracellularly or within cellular membranes. Among the up-regulated genes, several hitherto undescribed orthologues of structural proteins in humans were identified, but also genes that are potentially involved in the worms' defense against tannins. For example, T22D1.2, an orthologue of human basic salivary proline-rich protein (PRB) 2, and numr-1 (nuclear localized metal responsive) were found to be strongly up-regulated. Down-regulated genes were mainly associated with lysosomal activity, glycoside hydrolysis or the worms' innate immune response. No major differences were found between the groups treated with purified OPCs versus the crude extract. Investigations using GFP reporter gene constructs of T22D1.2 and numr-1 corroborated the intestine as the predominant site of the anthelmintic activity. The current findings support previous hypotheses of OPCs interacting with intestinal surface proteins and provide the first insights into the nematode's response to OPCs on a molecular level as a base for the identification of future drug targets.