Exploring the phthalates-induced neurotoxicity mechanisms of neurodegenerative diseases via network toxicology, single-cell transcriptomics and molecular dynamic simulation

Abstract

Phthalates are considered to be a neurotoxicant, widely used in construction materials, packaging, and various medical products. Few studies have focused on the association between exposure to phthalates and risks on neurodegenerative diseases and thus this study delved into the potential mechanisms by which phthalates could cause neurodegenerative diseases. Firstly, using network toxicology, we discovered ten phthalates exert significant toxic effects on the blood-brain barrier (BBB), in which di(2-ethylhexyl) phthalate (DEHP) and diisobutyl phthalate (DiBP) also exhibit marked neurotoxicity, immunotoxicity, and ecotoxicity. Disease ontology (DO) analysis revealed that the impacts of these plasticizers on neurodegenerative diseases are primarily manifested in three major conditions, including Parkinson's disease (PD), Lewy body disease (LBD), and Alzheimer's disease (AD), and further demonstrated that phthalates may induce the pathogenesis of three neurodegenerative diseases via modulating cellular apoptosis and neuroinflammatory pathways, such as the PI3K-Akt and JAK-STAT pathways. Furthermore, we pinpointed the BCL2, BCL2L1, IL6, IL10 and CCND1 as hub genes through diagnostic models by utilizing sample data of PD patients' tissues. Interestingly, we found that BCL2 expressed in astrocytes plays a crucial role in the phthalates-induced neurotoxicity in single-cell analysis. Subsequently, molecular docking and dynamics simulations observed that ten phthalates form a stable interaction with BCL2, especially DEHP, and cellular experiments confirmed that both DEHP and its metabolite MEHP significantly decreased BCL2 level in MPP⁺ -induced cell model and induced the transformation of astrocytes from the neuroprotective A2 to the pro-inflammatory A1 subtype. Therefore, our study offers novel insights into the neurotoxic effects of environmental pollutants, thereby establishing a theoretical foundation for the prevention and treatment of neurodegenerative diseases.

Keywords: Molecular dynamic simulation; Network toxicology; Neurodegenerative diseases; Neurotoxicity; Phthalates; Single-cell transcriptomics.