Silicon dioxide nanoparticles inhibit the effects of cold exposure on metabolism and inflammatory responses in brown adipocytes

Objective:Nanoparticles(NPs)in haze are potentially hazardous to health,which is more severe in the winter.Brown adipose tissue(BAT)plays important roles in obesity,insulin resistance,and diabetes.Though the toxicology of NPs has been intensively studied,few studies have been reported on the antagonistic effects between Silicon dioxide(SiO2)NPs and cold exposure in brown adipocytes.Materials and methods:We evaluated changes by quantitative real-time reverse-transcriptase polymerase chain reaction(qRT-PCR)on metabolism genes,plasticity genes and the inflammatory responses genes in brown adipocytes in vitro.Results:The expression of adipogenic genes PRDM16,Dio2,PGC-1α and UCP1 was upregulated upon cold exposure(P＜0.05),but downregulated by SiO2 NPs(P＜0.05).The results demonstrated that there was antagonistic effect between SiO2 NPs and cold exposure on the plasticity genes and metabolism genes in brown adipocytes,where the main effects of SiO2 NPs or cold exposure on the plasticity genes and metabolism genes were significant(P＜0.05).Moreover,the levels of interleukin(IL)-1β,IL-6 and tumor necrosis factor(TNF)-α were upregulated by SiO2 NPs or cold exposure(P＜0.05).The factorial analysis indicated that there was also antagonistic effect between SiO2 NPs and cold exposure on the toxic effects in brown adipocytes,in which the main effects of cold exposure and/or SiO2 NPs on the toxic effects were significant(P＜0.05).Conclusion:SiO2 NPs inhibit the effect of cold exposure on metabolic genes and inflammatory responses genes in brown adipocytes.