Abstract
Nickel oxide nanoparticles (Nano NiO) have been shown to cause pulmonary fibrosis; But, the underlying epigenetic mechanisms remain poorly understood. In this study, we aimed to investigate the role of lncRNA AP000487.1 in regulating PRKCB DNA methylation and the Toll-like receptor 4 (TLR4)/ Myeloid differentiation primary response 88 (MyD88)/ Nuclear factor kappa-B (NF-κB) pathway in Nano NiO-induced collagen formation. We found that lncRNA AP000487.1 was able to bind to the promoter region of the PRKCB gene by Chromosomal RNA pull-down experiments (Ch-RNA pull-down). Moreover, Nano NiO exposure led to down-regulation of lncRNA AP000487.1 expression and PRKCB DNA methylation, resulting in up-regulation of PRKCB expression, activation of the TLR4/MyD88/NF-κB pathway, and increased collagen formation in BEAS-2B cells. Conversely, overexpression of lncRNA AP000487.1 restored PRKCB expression, reduced its hypomethylation and attenuated TLR4/MyD88/NF-κB pathway activation and collagen formation. Furthermore, treatment with the DNA methylation inhibitor, decitabine, alleviated Nano NiO-induced PRKCB2 expression, TLR4/MyD88/NF-κB pathway activation, and collagen formation. Additionally, using PRKCB2 overexpression plasmid, PRKCB2 siRNA, and PRKCB2 protein inhibitor LY317615 influenced NF-κB pathway activity and collagen formation. Finally, TLR4 inhibitor (TAK-242) restrained Nano NiO-induced MyD88/NF-κB pathway activation and excessive collagen formation. In summary, we demonstrated that the down-regulated lncRNA AP000487.1 could cause PRKCB hypomethylation and increased expression, resulting in NF-κB pathway activation and collagen formation in Nano NiO-induced BEAS-2B cells. This is the first study to reveal the role of lncRNA AP000487.1 in regulating collagen formation in Nano NiO-exposed BEAS-2B cells. Our study identified that lncRNA AP000487.1/PRKCB hypomethylation/NF-κB pathway was a regulatory axis of BEAS-2B cells collagen excessive formation. Our findings indicate that lncRNA AP000487.1 and PRKCB DNA methylation may function as biomarkers or potential targets in response to Nano NiO exposure.