RESUMO
@#Objective To investigate the effect of cold stimulation on the phenotype of alveolar macrophages(MH-S cells) in mice. Methods MH-S cells were cultured at 37 ℃ for 24 h,and cold stimulated at 36,34 and 32 ℃ for 0,0. 5,1,3,6,9 and 12 h respectively. The mRNA transcription levels of interleukin-1β(IL-1β) and interleukin-10(IL-10) genes in MH-S cells were detected by qRT-PCR. MH-S cells were cultured at 37 ℃ for 24 h,and cold stimulated at 34 ℃ for 0. 5 h,which were detected for the mRNA transcription levels of tumor necrosis factor-α(TNF-α),inducible nitric oxide synthase(iNOS)and Arginase1(Arg1)genes by qRT-PCR(MH-S cells with 0 h cold stimulation as control),detected for the expression of iNOS and Arg1 by immunofluorescence assay(MH-S cells cultured at 37 ℃ for 0. 5 h as negative control)and detected for the expression levels of iNOS,TNF-α and nuclear factor-kappa B(NF-κB)by Western blot(MH-S cells cultured at 37 ℃ for 0. 5 h as negative control). Results The mRNA transcription levels of IL-1β and IL-10 genes in MH-S cells were the highest when the cells were cultured at 34 ℃ for 0. 5 h,therefore,the cold stimulation model of MH-S cells was established under this condition. Compared with the cells cultured for 0 h,the mRNA transcription levels of iNOS,TNF-α and Arg1genes in MH-S cells cultured at 34 ℃ for 0. 5 h increased significantly(t = 3. 733,12. 190 and 6. 793,respectively,each P < 0. 05). Compared with the negative control group,the fluorescence expression intensity of iNOS and Arg1 in MH-S cells in the stimulation group increased,especially iNOS,the expression levels of iNOS and TNF-α proteins increased with no significant difference(t = 0. 675 and 1. 514,respectively,each P > 0. 05),and the expression level of NF-κB increased significantly(t = 3. 092,P < 0. 05). Conclusion Cold stimulation at 34 ℃ for 0. 5 h can increase the expression of inflammatory factors such as IL-1β,IL-10,TNF-α,iNOS,Agr1 and NF-κB in MH-S cells,activate NF-κB signaling pathway in MH-S cells,induce the expression of inflammatory proteins and promote cell activation.