Differences in protein expression associated with ivermectin resistance in Caenorhabditis elegans

Abstract The indiscriminate administration of synthetic anthelmintics such as ivermectin contributes to the selection of subpopulations capable of resisting the drugs’ effects. To understand the mechanisms of ivermectin resistance in Caenorhabditis elegans, this study attempted to identify molecular targets. C. elegans lineages that were sensitive and resistant to ivermectin were used. Collected nematodes were added to an extraction buffer and macerated in liquid nitrogen for protein extraction. The extracted proteins were separated according to molecular weight by SDS-PAGE to verify their integrity. Subsequently, proteins from both lineages were separated using two-dimensional electrophoresis. The gels were analyzed and the relevant spots were excised and identified by mass spectrometry (NanoESI-Q-TOF and MASCOT®) and subsequently assessed by GO enrichment and STRING® analyses. The increased expression of proteins associated with high metabolic activity, such as ATP-2 and ENOL-1, which are responsible for ATP synthesis, was observed. Furthermore, proteins with involvement in mediating muscular function (MLC-1, ACT-1, and PDI-2), signaling (FAR-1 and FAR-2), and embryo development (VHA-2) were identified. Protein interaction analysis indicated that the majority of the identified proteins in the resistant lineages participated in the same reaction triggered by ivermectin.