Curcumin Inhibits Lipopolysaccharide-lnduced Mucin 5AC Hypersecretion and Airway Inflammation via Nuclear Factor Erythroid 2-Related Factor 2

Background： Excess mucus production is an important pathophysiological feature of chronic inflammatory airway diseases. Effective therapies are currently lacking. The aim of the study was to evaluate the effects ofcurcumin （CUR） on lipopolysaccharide （LPS）-induced mucus secretion and inflammation, and explored the underlying mechanism in vivo and in vitro. Methods： For the in vitro study, human bronchial epithelial （NCI-H292） cells were pretreated with CUR or vehicle for 30 min, and then exposed to LPS for 24 h. Next, nuclear factor erythroid 2-related factor 2 （Nrf2） was knocked down with Nrf2 small interfering RNA （siRNA） to confirm the specific role of Nrf2 in mucin regulation of CUR in NCI-H292 cells. In vivo, C57BL/6 mice were randomly assigned to three groups （n = 7 for each group）： control group, LPS group, and LPS ＋ CUR group. Mice in LPS and LPS ＋ CUR group were injected with saline or CUR （50 mg/kg） intraperitoneally 2 h before intratracheal instillation with LPS （ 100 μg/ml） for 7 days. Cell lysate and lung tissue were obtained to measured Mucin 5AC （MUC5AC） and Nrf2 mRNA and protein expression by a real-time polymerase chain reaction and Western blotting. Bronchoalveolar lavage fluid （BALF） was collected to enumerate total cells and neutrophils. HistopathologicaI changes of the lung were observed. Data were analyzed by one-way analysis of variance. Student＇s t-test was used when two groups were compared. Results： CUR significantly decreased the expression ofMUC5AC mRNA and protein in NCI-H292 cells exposed to LPS. This effect was dose dependent （2.424 ± 0.318 vs. 7.169 ± 1.785, t = 4.534, and 1.060 ± 0.197 vs. 2.340 ± 0.209, t = 7.716; both P 〈 0.05, respectively） and accompanied by increased mRNA and protein expression of Nrf2 （1.952 ± 0.340 vs. 1.142 ± 0.176, t = -3.661, and 2.010 ± 0.209 vs. 1.089 ±0. 132, t = -6.453; both P 〈 0.05, respectively）. Furthermore, knockdown of Nrf2 with siRNA increased MUC5A C mRN A expression by 47.7%, compared with levels observed in the siRNA-negative group （6.845 ± 1.478 vs. 3.391 ± 0.517, t = -3.821, P 〈 0.05）. Knockdown of Nrf2 with siRNA also markedly increased MUC5A C protein expression in NCI-H292 cells. CUR also significantly decreased LPS-induced mRNA and protein expression of MUC5A C in mouse lung （ 1.672 ± 0.721 vs. 5.961 ± 2.452, t = 2.906, and 0.480 ± 0.191 vs. 2.290 ± 0.834, t = 3.665, respectively; both P 〈 0.05）. Alcian blue/periodic acid-Schiff staining also showed that CUR suppressed mucin production. Compared with the LPS group, the numbers of inflammatory cells （247 ± 30 vs. 334 ± 24, t = 3.901, P 〈 0.05） and neutrophils （185 ± 22 vs. 246 ± 20, t = 3.566, P 〈 0.05） in BALF decreased in the LPS ＋ CUR group, as well as reduced inflammatory cell infiltration in lung tissue. Conclusion： CUR inhibits LPS-induced airway mucus hypersecretion and inflammation through activation of Nrf2 possibly.

Clinical features and risk factors associated with severe COVID-19 patients in China

Background::Coronavirus disease 2019(COVID-19),which is caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),has rapidly spread throughout the world.In this study,we aimed to identify the risk factors for severe COVID-19 to improve treatment guidelines.Methods::A multicenter,cross-sectional study was conducted on 313 patients hospitalized with COVID-19.Patients were classified into two groups based on disease severity(nonsevere and severe)according to initial clinical presentation.Laboratory test results and epidemiological and clinical characteristics were analyzed using descriptive statistics.Univariate and multivariate logistic regression models were used to detect potential risk factors associated with severe COVID-19.Results::A total of 289 patients(197 nonsevere and 92 severe cases)with a median age of 45.0(33.0,61.0)years were included in this study,and 53.3%(154/289)were male.Fever(192/286,67.1%)and cough(170/289,58.8%)were commonly observed,followed by sore throat(49/289,17.0%).Multivariate logistic regression analysis suggested that patients who were aged≥65 years(OR:2.725,95%confidence interval[CI]:1.317-5.636;P=0.007),were male(OR:1.878,95%CI:1.002-3.520,P=0.049),had comorbid diabetes(OR:3.314,95%CI:1.126-9.758,P=0.030),cough(OR:3.427,95%CI:1.752-6.706,P<0.001),and/or diarrhea(OR:2.629,95%CI:1.109-6.231,P=0.028)on admission had a higher risk of severe disease.Moreover,stratification analysis indicated that male patients with diabetes were more likely to have severe COVID-19(71.4%vs.28.6%,χ2=8.183,P=0.004).Conclusions::The clinical characteristics of those with severe and nonsevere COVID-19 were significantly different.The elderly,male patients with COVID-19,diabetes,and presenting with cough and/or diarrhea on admission may require close monitoring to prevent deterioration.