アクリルアミド曝露誘発性ノルアドレナリン神経変性におけるミクログリアの役割の検討およびトランスクリプトーム解析

抄録

Neurotoxicity of environmental electrophiles such as 1-bromopropane (1-BP) and acrylamide (ACR) has been reported in human and experimental animals. Our previous studies found that exposure to 1-BP or ACR can cause degeneration of noradrenergic axons in murine brain, while the mechanism remain obscure. To further investigate the underlying mechanism, 1C11 mouse neuroectodermal stem cell line and BV2 microglia cell line were used in this study. 1C11 stem cells were differentiated into noradrenergic neural cells (1C11NE), and then exposed to 0~1mM ACR or to conditioned media (CM) of ACR-treated BV2 microglia. Evaluation of cytotoxicity and plasma membrane integrity by MTS and LDH assay showed that exposure to ACR alone did not decrease cell viability, nor increase LDH release in 1C11NE cells. Exposure to BV2 CM did not decrease 1C11NE cell viability but increased LDH release. Quantification of neurite length showed that treatment with ACR alone did not decrease neurite length of 1C11NE, but treatment with CM of ACR-exposed BV2 microglia significantly decreased neurite length. The addition of ACR into CM of PBS-exposed BV2 also significantly decreased neurite length of 1C11NE. Moreover, transcriptomic RNA-seq analysis identified 2544 differentially expressed genes in 1C11NE after exposure to ACR or CM of BV2. WGCNA clustering and gene ontology analysis revealed different gene expression profiles and enriched different GO items/pathways in different treatment groups. The above results suggest that microglia play a critical role in ACR-induced retraction of noradrenergic axons.