Objective:To investigate the regulatory effects of mitofusin 1 (MFN1) on lipopolysaccharide (LPS)-induced Raw264.7 mouse macrophages pyroptosis and to provide reference for further study on the prevention of inflammation and fibrosis caused by macrophage dysfunction.Methods:Raw264.7 mouse macrophages were cultured in vitro and used to construct a model of LPS-induced pyroptosis. CCK-8 staining, PI staining, LDH release assay and Western blot were used to verify the Raw264.7 pyroptosis induced by LPS. MFN1 expression was detected by Western blot. DCFH-DA probe was used to detect the synthesis of total reactive oxygen species (ROS); Mito-SOX was used to detect mitochondrial ROS; JC-1 mitochondrial membrane potential was detected by fluorescence probe to reflect mitochondrial damage. Based on Ubibrowser database, it was predicted that MFN1 could bind to a variety of E3 ubiquitin ligases. Then, immunofluorescence and co-immunoprecipitation (CO-IP) were used to analyze MFN1 ubiquitination. An overexpression plasmid for MFN1 was constructed and transfected into Raw264.7 cells to detect the changes in pyroptosis and mitochondrial function. Results:LPS could induce the pyroptosis of Raw264.7 cells and mitochondrial dysfunction. MFN1 expression was decreased after LPS stimulation. Ubiquitinated MFN1 was detected by CO-IP. Ubiquitination inhibitor MG-132 inhibited LPS-induced expression of pyroptosis-related proteins including NLRP3, Pro-caspase-1, Caspase-1, IL-1β and IL-18 and improved mitochondrial function. MFN1 overexpression relieved the mitochondrial dysfunction and pyroptosis of Raw264.7 cells induced by LPS.Conclusions:The ubiquitination of MFN1 induced by LPS was involved in mitochondrial dysfunction and macrophage pyroptosis, suggesting that MFN1 was a potential target for the treatment of macrophage-induced inflammation and related diseases.

Objective:To explore effect of Glioma-associated oncogene family zinc finger 1(GLI1)on hypoxia induced trans-formation of NR8383 to M1 phenotype and development of pulmonary hypertension(PH).Methods:Fifteen adult male Wistar rats were randomly divided into control group,hypoxia PH model group and hypoxic PH with GANT61 treatment group,with 5 rats in each group.PH related indexes of rats were detected by small animal ultrasound and right cardiac catheter experiment to determine effect of GLI1 specific inhibitor GANT61 on progression of PH.Pulmonary arterial thickness was measured by HE staining.α-SMA and M1 polarization markers TNF-α and IL-1β expressions were determined by immunohistochemistry.M1 polarization markers CD86 and TNF-α expressions were determined by immunofluorescence.GLI1 expression and NF-κB protein were detected by Western blot.mRNA expressions of iNOS,CD86,TNF-α,IL-1β and IL-12 were detected by qRT-PCR.CHIP-PCR verified that GLI1 regulates NF-κB promoter activity.IL-12 content was detected by ELISA.Rat pulmonary artery smooth muscle cells proliferation was detected by CCK-8.Results:GLI1 inhibitor GANT61 could alleviate symptoms of PH in hypoxic rats(P<0.05).Compared with hypoxic group,inhibition of GLI1 reduced expressions of TNF-α and IL-1β in rat lung tissue(P<0.05).In cell experiments,hypoxia induced M1 polarization of NR8383 by up-regulating GLI1 to activate NF-κB pathway,GLI1 overexpression increased expressions of iNOS,CD86,TNF-α,IL-1β and IL-12 in M1 macrophages(P<0.05).NR8383 culture supernatants could stimulate pulmonary artery smooth muscle cell proliferation(P<0.05)and contribute to development of PH.Conclusion:Hypoxia activates NF-κB pathway by up-regulating GLI1 to induce M1 polarization of macrophages contributes to development of PH.