转染 DPP-4 siRNA 或（和）加入 SP600125的小鼠肺泡 巨噬细胞极化及JNK/AP-1信号通路激活情况观察.

Objective To observe the polarization of alveolar macrophages and the activation of JNK/AP-1 signaling pathway in mice transfected with dipeptidyl peptidase-4 (DPP-4) siRNA or (and) added with c-Jun N-terminal kinase (JNK) inhibitor (SP600125) . Methods Mouse alveolar macrophages (MH-S) were cultured in vitro and randomly grouped into： control group (transfected with empty siRNA), siDPP-4 group (transfected with DPP-4 siRNA), lipopolysaccharide (LPS) group (transfected with empty siRNA+ LPS), siDPP-4+LPS group (transfected with DPP-4 siRNA+ LPS), LPS+SP600125 group (transfected with empty siRNA+ LPS combined with SP600125), and siDPP-4+LPS+ SP600125 group (transfected with DPP-4 siRNA+ LPS combined with SP600125), respectively. The expression levels of M1 and M2 polarization markers CD86 and CD206 proteins and the phosphorylation of JNK and activator protein-1 (AP-1) transcription proteins (c-Jun and c-Fos) in macrophages were detected by Western blotting, the mRNA levels of M1 markers [CD86, tumor necrosis factor (TNF) -α, iNOS, IL-1β] and M2 markers [CD206, arginine kinase-1 (ARG-1), IL-4, IL-10] in macrophages were detected by RT-qPCR, and M1 proinflammatory factor NO and intracellular reactive oxygen species (ROS) production in macrophage supernatant were detected by nitric oxide (NO) assay kit and immunofluorescence, respectively. Results Compared with the control group, the production of M1 proinflammatory factors NO and ROS, and the expression levels of M1 polarization markers (CD86 protein and CD86, TNF-α, iNOS, IL-1β mRNA) increased, and the expression levels of M2 polarization markers (CD206 protein and CD206, ARG-1, IL-4, IL-10 mRNA) decreased in the LPS group (all P<0. 05) . Compared with the LPS group, the production of M1 proinflammatory factors NO and ROS, and the expression levels of M1 polarization markers (CD86 protein and CD86, TNF- α, iNOS, IL-1β mRNA) increased, and the expression levels of M2 polarization markers (CD206 protein and CD206, ARG-1, IL-4, IL10 mRNA) decreased in the siDPP-4+LPS group (all P<0. 05) . Compared with the LPS group, the relative expression levels of p-JNK/JNK, p-c-Jun/c-Jun and p-c-Fos/c-Fos protein phosphorylation increased in the siDPP-4 +LPS group (all P< 0. 05) . Compared with the siDPP-4+LPS group, the relative expression levels of p-JNK/JNK, p-c-Jun/c-Jun, p-c-Fos/cFos protein phosphorylation decreased in the siDPP-4+LPS+SP600125 group (all P<0. 05) . Conclusions Transfection of DPP-4 siRNA can promote the M1 polarization of mouse alveolar macrophages induced by LPS, inhibit the M2 polarization of alveolar macrophages, and increase the phosphorylation expression of JNK, c-Jun and c-Fos proteins. Addition of JNK inhibitor may reduce the increase in phosphorylation expression of JNK, c-Jun and c-Fos proteins caused by transfection of DPP-4 siRNA. The mechanism of DPP-4 siRNA transfection promoting M1 polarization in mouse alveolar macrophages induced by LPS may be related to the activation of JNK/AP-1 signaling pathway. [ABSTRACT FROM AUTHOR]