Objective To investigate the effects of wedelolactone (WEL) on lipopolysaccharide (LPS)-induced pyroptosis of alveolar epithelial cells and AMP-activated protein kinase/nucleotide binding oligomeric domain like receptor 3 (NLRP3)/cysteinyl aspartate specific proteinase-1 (Caspase-1) signaling pathway. Methods Human lung epithelial cells BEAS-2B were treated with 5 - 200 μmol/L wedelolactone, and cell activity was detected using MTT assay. The alveolar epithelial cells were divided into control group, lipopolysaccharide group (LPS group), 10 μmol/L wedelolactone group (WEL-L group), 20 μmol/L wedelolactone group (WEL-M group), 40 μmol/L wedelolactone group (WEL-H group), 40 μmol/L wedelolactone+10 μmol/L AMPK inhibitor Compound C group (WEL-H+Compound C group), and 20 μmol/L Caspase-1 inhibitor Z-YVAD-FMK group (Z-YVAD-FMK group). Transmission electron microscopy was applied to observe the microstructure of cells. ELISA was applied to detect levels of inflammatory factors such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-8 (IL-8). Immunofluorescence was applied to detect Caspase-1 and gasdermin family proteins (DGSDMD). Western blot was applied to detect protein expression levels of AMPK, NLRP3, and Caspase-1. Results Wedelolactone concentrations of 10, 20 and 40 μmol/L were selected for follow-up experiments. Compared with Control group, LPS group showed decreased cell activity, severe damage, cell contraction, mitochondrial ridge breakage and decreased number, increased levels of TNF-α, IL-1β, IL-8 and GSDMD, NLRP3, Caspase-1 expression, and decreased p-AMPK/AMPK expression (P<0.05). Wedelolactone treatment could significantly improve LPS-induced pyrosis of alveolar epithelial cells (P<0.05). Compound C could partially reverse the effect of wedelactone on LPS-induced pyrodeath of alveolar epithelial cells (P<0.05). Z-YVAD-FMK treatment also significantly improved LPS-induced pyroptosis of alveolar epithelial cells (P<0.05). Conclusion Wedelolactone can inhibit LPS-induced pyroptosis of pulmonary alveolar epithelial cells by inhibiting AMPK/NLRP3/Caspase-1 signaling pathway.
Objective To analyze the distribution of pathogens, drug susceptibility and multi-drug resistant bacteria (MDRB) in elderly patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) complicated with pneumonia. Methods The clinical data of patients whose discharge diagnosis included AECOPD with pneumonia or pulmonary infection from January 2012 to December 2015 were retrospectively analyzed. Strain identification and drug sensitivity analysis were performed in the pathogenic bacterias isolated from sputum culture. Results A total of 1 978 patients were enrolled in this study, and pathogenic bacterias were isolated from the sputum of 708 patients, including 485 cases of community-acquired pneumonia (CAP) and 223 cases of hospital-acquired pneumonia (HAP); and 786 strains of pathogens were isolated (501 strains from CAP cases, 285 strains from HAP cases), including 448 strains of Gram-negative (G–) bacilli (57.0%), 117 strains of Gram-positive (G+) cocci (14.9%), and 221 strains of fungi (28.1%). Susceptibility testing results showed that G– bacilli were highly resistant to penicillins, third generation cephalosporins, ciprofloxacin, gentamicin, etc., and G+ cocci were highly resistant to penicillin, clindamycin and erythromycin. There were 238 strains of MDRB, mainly including 69 strains of Acinetobacter baumanii [multiple drug resistance rate (MDRR)=67.6%], 27 strains of Escherichia coli (MDRR=52.9%), 25 strains of Klebsiella pneumoniae (MDRR=34.2%), 33 strains of Pseudomonas aeruginosa (MDRR=33.0%) and 24 strains of Stenotrophomonas maltophilia (MDRR=100.0%). MDRR of Enterococcus genus and methicillin-resistant Staphylococcus aureus was 50.0% and 48.0%, respectively. Conclusions The pathogenic bacterias in elderly AECOPD patients complicated with pneumonia are mainly G– bacterias, and the proportion of fungal infection tends to increase. Bacterial drug resistance is serious and the MDRB tends to increase, especially in patients with HAP. Physicians should early find out the characteristics of local pathogenic bacteria and drug sensitivity, rationally select antibiotics, reduce the occurrence of drug-resistant strains and superinfection when treating the elderly patients with AECOPD complicated with pneumonia.