A Shotgun Proteomic-Based Approach with a Q-Exactive Hybrid Quadrupole-Orbitrap High-Resolution Mass Spectrometer for the Assessment of Pesticide Mixture-Induced Neurotoxicity on a 3D-Developed Neurospheroid Model from Human Brain Meningiomas: Identification of Trityl-Post-Translational Modification

Abstract

The widespread use of pesticides, particularly in combinations, has resulted in enhanced hazardous health effects. However, little is known about their molecular mechanism of interactions. The aim of this study was to assess the neurotoxicity effect of pesticides in mixtures by adopting a 3D in vitro developed neurospheroid model, followed by treatment by increased concentrations of pesticides for 24 h and analysis by a shotgun proteomic-based approach with high-resolution tandem mass spectrometry. Three proteins, namely, glyceraldehyde-3-phosphate-dehydrogenase (GAPDH), α-enolase, and phosphoglyceratekinase-1, were selected as key targets in the metabolic process. Only high doses of pesticides mitigated cell-density proliferation with the occurrence of apoptotic cells, which unlikely makes any neurological alterations in environmental regulatory exposures. The proteomic analysis showed that majority of altered proteins were implicated in cell metabolism. De novo peptide sequencing revealed ion losses and adduct formation, namely, a trityl-post-translational modification in the active site of 201-GAPDH protein. The study also highlights the plausible role of pyrethroids to be implicated in the deleterious effects of pesticides in a mixture. To the best of our knowledge, our finding is the first in toxicoproteomics to deeply elucidate pesticides' molecular interactions and their ability to adduct proteins as a pivotal role in the neurotoxicity mechanism.