Objective:To investigate the inhibitory effect and mechanism of heme oxygenase-1 (HO-1) on the inflammatory response of macrophages.Methods:Mouse macrophage strain RAW264.7 was cultured in vitro, and the cells in the logarithmic growth phase were used for the experiment. The RAW264.7 cells were divided into four groups. In blank control group, the cells were continuously incubated and received no treatment (cultured at 37 ℃, 95% air, 5% CO 2). In lipopolysaccharide (LPS) model group, 1 mg/L LPS was added to the medium to prepare LPS challenge model. In HO-1 inducer group, the cells were incubated with 30 μmol/L HO-1 inducer hemin for 1 hour, and then 1 mg/L LPS was added for incubation. In HO-1 inhibition group, the cells were incubated with 5 μmol/L HO-1 specific antagonist Zinc protoporphyrin Ⅸ (ZnPPⅨ) for 0.5 hour, and then 1 mg/L LPS was added for incubation. After 48 hours of incubation with LPS, the supernatant of each group was taken, and the protein expressions of HO-1, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), thioredoxin interacting protein (TXNIP), NOD-like receptor protein 3 (NLRP3) and mitochondrial autophagy marker microtubule-associated protein 1 light chain 3B (LC-3B) were detected by Western blotting. The expression of reactive oxygen species (ROS) was detected by immunofluorescence staining. Results:Compared with the blank control group, the cells in the LPS model group had a certain stress response, and autophagy occurred in mitochondria, but the expression of some inflammatory factors was restricted, which was related to the impairment of cell function. The protein expressions of HO-1, IL-1β, LC-3B, ROS were significantly increased, the protein expressions of TNF-α, TXNIP, and NLRP3 were decreased significantly, indicating that the cells were seriously injured after LPS challenge, and the model was successfully established. Compared with the LPS model group, HO-1 protein expression in the HO-1 inducer group was significantly increased (HO-1/GAPDH: 0.31±0.03 vs. 0.22±0.03, P < 0.05), the protein expressions of TNF-α, IL-1β, TXNIP, NLRP3, LC-3B and ROS were significantly inhibited [TNF-α protein (TNF-α/GAPDH): 0.08±0.01 vs. 0.45±0.05, IL-1β protein (IL-1β/GAPDH): 0.50±0.01 vs. 0.82±0.03, TXNIP protein (TXNIP/GAPDH): 0.21±0.02 vs. 0.28±0.02, NLRP3 protein (NLRP3/GAPDH): 0.11±0.01 vs. 0.17±0.02, LC-3B protein (LC-3B/GAPDH): 0.67±0.04 vs. 0.92±0.12, ROS (fluorescence intensity): 80.9±12.5 vs. 94.1±19.5, all P < 0.05], indicating that HO-1 could inhibit inflammatory response and oxidative stress, and reduce mitochondrial autophagy. Antagonizing HO-1 could increase inflammatory response, oxidative stress and mitochondrial autophagy, the inhibitory degree of TNF-α and IL-1β expression was significantly reduced as compared with the HO-1 inducer group [TNF-α protein (TNF-α/GAPDH): 0.26±0.02 vs. 0.08±0.01, IL-1β protein (IL-1β/GAPDH): 0.76±0.01 vs. 0.50±0.01, both P < 0.05], the protein expressions of TXNIP, NLRP3, LC-3B and ROS were significantly increased as compared with the LPS model group [TXNIP protein (TXNIP/GAPDH): 0.43±0.02 vs. 0.28±0.02, NLRP3 protein (NLRP3/GAPDH): 0.24±0.02 vs. 0.17±0.02, LC-3B protein (LC-3B/GAPDH): 1.12±0.07 vs. 0.92±0.12, ROS (fluorescence intensity): 112.0±17.0 vs. 94.1±19.5, all P < 0.05]. Conclusion:HO-1 can reduce the inflammatory response by inhibiting the activation of TXNIP/NLRP3 inflammasome and reducing the release of inflammatory mediators.

OBJECTIVE To investigate the impacts of isorhynchophylline （IRN） on airway inflammation in asthmatic mice by regulating the monocyte chemotactic protein-1 （MCP-1）/CC chemokine receptor 2 （CCR2） signaling pathway. METHODS The asthmatic mice model was established by injecting and inhaling ovalbumin. The successfully modeled mice were randomly grouped into asthma group， IRN low-dose group （IRN-L， intragastric administration of 10 mg/kg IRN）， IRN high-dose group （IRN-H， intragastric administration of 20 mg/kg IRN）， IRN-H+CCL2 group [intragastric administration of 20 mg/kg IRN+intraperitoneal injection of 7.5 ng CC chemokine ligand 2 （CCL2）] and positive control group （intraperitoneal injection of 2 mg/kg dexamethasone）. The mice injected and inhaled with sterile phosphate-buffered solution were included in the blank control group， with 10 mice in each group. The mice in administration groups were given relevant medicine once a day， for consecutive 2 weeks. The levels of airway hyperreactivity indexes such as enhanced （Penh） value， tumor necrosis factor-α （TNF-α），interleukin-13 （IL-13） and IL-4 in serum， the number of eosinophil （EOS）， lymphocyte （LYM） and neutrophils （NEU） in alveolar lavage fluid and the protein expressions of MCP-1 and CCR2 in lung tissue were observed in each group； the pulmonary histopathological changes were observed， and inflammatory cell infiltration score was evaluated. RESULTS Compared with the blank control group， the infiltration of inflammatory cells in the lung tissue of mice was more significant in the asthma group， and there was swelling and shedding of cells； inflammatory infiltration score， Penh value， the levels of IL-4， IL-13 and TNF-α， the number of EOS， NEU and LYM， the protein expressions of MCP-1 and CCR2 were increased significantly （P＜0.05）. Compared with the asthma group， the pathological injuries of the IRN-L group， IRN-H group and positive control group were improved， and the above quantitative indexes were decreased significantly （P＜0.05）. Compared with the IRN-L group， the above quantitative indexes of the IRN-H group and positive control group were decreased significantly （P＜0.05）. There was no statistical significance in the above quantitative indexes between the IRN-H group and the positive control group （P＞0.05）. Compared with the IRN-H group， the above quantitative indexes of the IRN-H+CCL2 group were increased significantly （P＜0.05）. CCL2 reversed the protective effect of high-dose IRN on asthmatic mice. CONCLUSIONS IRN may reduce the release of airway inflammatory factors in asthmatic mice by inhibiting the activation of the MCP-1/CCR2 signaling pathway， so as to achieve the purpose of improving asthma.