Nongenomic effects and mechanistic study of butyl benzyl phthalate-induced thyroid disruption: Based on integrated in vitro, in silico assays and proteome analysis

Based on in vitro and in silico assays as well as proteome analysis, this study explored the nongcnomic mechanism for butyl benzyl phthalate (BBP)-induced thyroid disruption. Molecular docking simulations showed that BBP could dock into the Arg-Gly-Asp (RGD) domain of intcgrin alpha(v)beta(3) and form hydrogen bonds with a docking energy of -35.80 kcal/ mol. This chemical enhanced rat pituitary tumor cell (GH3) proliferation and exhibited thyroid hormone-disrupting effects at 5-10 mu mol/L. Meanwhile, BBP upregulated beta(3) gene expression and activated the downstream mitogcnactivated protein kinase (MAPK) pathway in GH3 cells. Interestingly, GH3 cell proliferation was attenuated by intcgrin alpha(v)beta(3) inhibitor (RGD peptide) or ERK1/2 inhibitor (PD98059), suggesting that the disruptions might be partly attributed to its interaction with integrin alpha(v)beta(3 )and activation of MAPK. Furthermore, quantitative proteomic analysis of zebrafish embryos exposed to BBP at an environmentally relevant concentration of 0.3 mu mol/L revealed that BBP perturbed proteins and pathways related to cell communication (e.g., integrin binding) and signal transduction (e.g., MAPK signaling pathway). Taken together, our results supported that the biological effects of BBP-activated integrin alpha(v)beta(3) mediated by the nongenomic pathway play an important role in its thyroid disruption. Capsule: The nongenomic pathway plays a vital role in the thyroid disruption-inducing actions of BBP.

Automated summary

Based on in vitro and in silico assays as well as proteome analysis, this study explored the nongenomic mechanism for BBP-induced thyroid disruption. The results showed that BBP could dock into the RGD domain of integrin α(v)β(3) and activate the MAPK pathway, promoting cell proliferation. Furthermore, BBP perturbed proteins and pathways related to cell communication and signal transduction.