Immunotoxicity Assessment Of Tetrabromodiphenyl Ether Based On The Enlightenment Of Clinical

Object:Polybrominated diphenyl ethers are a novel type of persistent organic pollutants that are linked to a variety of clinical diseases.In clinical samples,2,2’,4,4’-tetrabromodiphenyl ether is one of the most commonly identified and hazardous PBDEs congeners.The immune system is an important biological organism’s defense mechanism and a sensitive indication for assessing the safety of exogenous chemicals.In this study,the immunotoxicity of BDE-47 was assessed by clinical analysis and in vivo and in vitro experiments.Methods:The study on the immunological function of PBDEs was searched through databases,and a meta-analysis was performed to assess the risk of immunotoxicity of PBDEs.The effects of BDE-47 on the immune organs and blood system of mice were assessed by an in vivo exposure experiment.The targets of BDE-47were searched and predicted by databases,and obtain BDE-47 immunotoxicity targets by intersected with immunological database targets.The interaction network of targets was constructed,and high-frequency targets in the network were screened for enrichment analysis and KEGG pathway analysis.RAW264.7 cell was utilized for in vitro exposure experiment,and cytotoxicity was detected by CCK8 assay and LDH leakage rate;western blot assay was used to detect endoplasmic reticulum stress-related proteins,and the flow cytometry in combination with endoplasmic reticulum inhibitors was used to study the relationship between endoplasmic reticulum stress and BDE-47-induced apoptosis and immune function impairment;Fluo-4 AM was used to detect intracellular Ga²⁺levels,and the relationship between intracellular Ga²⁺and BDE-47-induced apoptosis and immune function impairment was detected by flow cytometry in combination with Calcium chelator.Results:Meta-analysis results revealed that PBDEs could inhibit T lymphocyte proliferation and NK cell viability,reduce the ratio of CD3⁺CD8⁺and CD4⁺/CD8⁺cells,and lower IFN-γand Ig M levels in animals.BDE-47 suppressed body weight increase,spleen and thymus indices,and leukocyte,lymphocyte,monocyte,and granulocyte counts in mice after administered in vivo.In vitro exposure to BDE-47 reduced RAW264.7cell viability,increased LDH release,and increased the expression of GRP78 and CHOP proteins.BDE-47triggered apoptosis,hindered phagocytosis,increased the expression of the M1-type cell marker i NOS protein,and decreased the expression of the M2-type cell marker Arg1,according to flow cytometry tests.The endoplasmic reticulum stress inhibitor lowered intracellular Ga²⁺levels,whereas BDE-47 increased intracytoplasmic calcium ion levels.Calcium chelators decreased the expression of the endoplasmic reticulum stress proteins CHOP and GRP78,diminished BDE-47-induced apoptosis,increased cell phagocytosis,and inhibited the expression of the M1-type marker i NOS protein.Conclusion:BDE-47 exposure can increase intracellular Ga²⁺levels,induce endoplasmic reticulum stress,cause cell apoptosis,inhibits phagocytosis,and converts macrophages toward M1-type transformation.