Inhibition of METTL3 alleviated LPS-induced alveolar epithelial cell apoptosis and acute lung injury via restoring neprilysin expression.

AIMS: To investigate the role and mechanisms of methyltransferase-like 3 (METTL3) in the pathogenesis of lipopolysaccharide (LPS)-induced acute lung injury (ALI). MAIN METHODS: LPS intratracheally instillation was applied in alveolar epithelial cell METTL3 conditional knockout (METTL3-CKO) mice and their wild-type littermates. In addition, METTL3 inhibitor STM2457 was used. LPS treatment on mouse lung epithelial 12 (MLE-12) cell was applied to establish an in vitro model of LPS-induced ALI. H&E staining, lung wet-to-dry ratio, and total broncho-alveolar lavage fluid (BALF) concentrations were used to evaluate lung injury. Overall, the m6A level was determined with the m6A RNA Methylation Quantification Kit and dot blot assay. Expression of METTL3 and neprilysin were measured with immunohistochemistry, immunofluorescence, immunofluorescence-fluorescence in situ hybridization, and western blot. Apoptosis was detected with TUNEL, western blot, and flow cytometry. The interaction of METTL3 and neprilysin was determined with RIP-qPCR and MeRIP. KEY FINDINGS: METTL3 expression and apoptosis were increased in alveolar epithelial cells of mice treated with LPS, and METTL3-CKO or METTL3 inhibitor STM2457 could alleviate apoptosis and LPS-induced ALI. In MLE-12 cells, LPS-Induced METTL3 expression and apoptosis. Knockdown of METTL3 alleviated, while overexpression of METTL3 exacerbated LPS-induced apoptosis. LPS treatment reduced neprilysin expression, the intervention of neprilysin expression negatively regulated apoptosis without affecting METTL3 expression, and mitigated the promoting effect of METTL3 on LPS-induced apoptosis. Additionally, METTL3 could bind to the mRNA of neprilysin, and reduce its expression. SIGNIFICANCE: Our findings revealed that inhibition of METTL3 could exert anti-apoptosis and ALI-protective effects via restoring neprilysin expression.

Symptoms at disease onset predict prognosis in COVID-19 disease.

The main clinical manifestations of coronavirus disease 2019 (COVID-19) onset are respiratory symptoms, including cough, sputum, and dyspnea. However, a significant proportion of patients initially manifested non-respiratory symptoms, such as fever, myalgia, and diarrhea. Here, we compared the different characteristics and outcomes between the patients with respiratory symptoms and non-respiratory symptoms at illness onset. The patients admitted to the respiratory departments from eight hospitals in Hunan and Guangxi Province with nucleic acid-positive severe acute respiratory syndrome coronavirus (SARS-CoV-2) were recruited. Epidemiological information, clinical manifestations, laboratory findings, and radiological characteristics, treatment regimens, and outcomes data were recorded and analyzed. The median age of the recruited 541 subjects was 43 years (IQR, 33-55). Of the 541 subjects, 404 (74.5%) subjects had initial symptom that were respiratory, while 137 (25.5%) subjects had non-respiratory symptoms. Respiratory COVID-19 subjects had more secondary bacterial infections (8.7% vs 0.0%, P < 0.001), needed the intensive care unit more (9.7% vs 2.2%, P = 0.005), non-invasive ventilation more (7.2% vs 1.5%, P = 0.004), developed ARDS more (11.4% vs 2.2%, P = 0.001) and needed longer time to recover (18.5 vs 16.7 days, P = 0.003) compared to predominately non-respiratory COVID-19 subjects. The multivariate model showed that age (OR = 1.04, P = 0.01), dyspnea (OR = 4.91, P < 0.001) and secondary bacterial infection (OR = 19.8, P < 0.001) were independently associated with development of ARDS among COVID-19 patients. We identify COVID-19 subjects with dyspnea at disease onset who have a worse prognosis. We also demonstrate age and secondary bacterial infections to be independently associated with ARDS development in subjects with COVID-19.ABBREVIATIONS: COVID-19: Coronavirus disease 2019; ARDS: acute respiratory distress syndrome; IQR: interquartile range; ICU: intensive care unit; CDC: Chinese Center for Disease Control and Prevention.

The Effect of Noninvasive Ventilation Support on COVID-19 Patients and Risk Factors for Invasive Ventilation - A Retrospective and Multicenter Study.

BACKGROUND: Oxygen therapy (OT) is the most widely used supportive regime in patients with hypoxemic acute respiratory failure (ARF) due to severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection. The aim of this study was to identify the effect of noninvasive ventilation support on coronavirus disease 2019 (COVID-19) patients and risk factors for invasive mechanical ventilation (IMV). METHODS: We retrospectively analyzed confirmed COVID-19 subjects from nine hospitals outside Wuhan. All hospitalized patients who tested positive for COVID-19 by real-time polymerase chain reaction between January 1st and March 31st, 2020, were recruited. The patients were divided into four groups based on the most advanced OT regime, including no OT, nasal oxygen therapy, high-flow nasal oxygen therapy (HFNOT) or noninvasive ventilation (NIV), and IMV. Multiple logistic regression models were performed to determine risk factors for IMV. RESULTS: Of the 683 recruited subjects, 315 (46.1%) subjects did not need OT, 300 (43.9%) received nasal oxygen therapy, 51 (7.5%) received HFNOT or NIV, while 17 (2.5%) subjects had to be intubated. The lactate in the OT group was higher than in the no OT group (2.7 vs 1.6, P = 0.02). In addition, HFNOT or NIV patients had a higher respiratory rate, but a lower PaO2 (P < 0.001). HFNOT and NIV had an obvious beneficial effect on ARF with 75% of COVID-19 patients recovering from respiratory failure. Patients with IMV were older (P < 0.001), had a higher rate of hypertension (P < 0.001) and more secondary bacterial infections (P < 0.001) compared to those without intubation. The multivariate model showed that secondary bacterial infection (OR = 6.87, P = 0.009) was independently associated with IMV failure among COVID-19 patients. CONCLUSION: We identified that HFNOT and NIV had an obvious beneficial effect on ARF among COVID-19 patients. We also demonstrated that secondary bacterial infection was an independent risk factor for NIV failure in patients infected by SARS-COV2.

Spectrum and Clinical Characteristics of Symptomatic and Asymptomatic Coronavirus Disease 2019 (COVID-19) With and Without Pneumonia.

Background: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, has become a global pandemic. Based on symptoms, COVID-19 cases can be classified as symptomatic or asymptomatic. However, there is limited information about the differences between COVID-19 patients with and without pneumonia. Our study aimed to further discuss the spectrum and clinical characteristics of symptomatic and asymptomatic COVID-19 patients with and without pneumonia. Methods: In China, all COVID-19 cases are hospitalized in designated hospitals until two continuous negative oropharyngeal swabs obtained, which allows the professional monitoring of symptoms and clinical characteristics. We stratified all COVID-19 cases in our database and evaluated clinical characteristics in different COVID-19 subgroups (symptomatic with pneumonia, symptomatic without pneumonia, asymptomatic with pneumonia, and asymptomatic without pneumonia). Results: According to symptoms and laboratory and radiologic findings, COVID-19 cases were defined as symptomatic with pneumonia, symptomatic without pneumonia, asymptomatic with pneumonia, or asymptomatic without pneumonia. There were differences in the clinical characteristics and prognosis among the four groups. Both non-invasive mechanical ventilation (18, 4.2%) and invasive mechanical ventilation (11, 2.6%) were applied in only the symptomatic with pneumonia group. Likewise, extracorporeal membrane oxygenation and continuous renal replacement therapy were applied in only the symptomatic with pneumonia group. There were no differences in viral load, the durations of viral shedding, and hospitalization among the four groups. Conclusion: We have defined a comprehensive spectrum of COVID-19 with and without pneumonia. The symptomatic with pneumonia group consumed more medical resources than the other groups, and extra caution and monitoring should be applied in this group. The asymptomatic COVID-19 group had a similar viral load and viral shedding duration as the symptomatic COVID-19 group.

Current Status of the Treatment of COPD in China: A Multicenter Prospective Observational Study.

Background: There is a large gap in the treatments for patients with COPD according to the Global Initiative for COPD (GOLD) recommendations. Determining the situation of therapies in the real world is necessary. This study aimed to characterize the real-world practical therapies of COPD and prognosis of patients after treatment for 1 year. Methods: This study was a multicenter prospective observational study performed using a database set up by the Second Xiangya Hospital of Center South University. Detailed usage information for pharmacotherapies and nonpharmacotherapies for patients was collected, as well as the consistency of recommendations and patient adherence. Moreover, the effect of therapies after 1 year was calculated by comparing lung function and symptoms. Results: Ultimately, 4,796 patients with COPD from 12 hospitals in China were eligible. LAMA (39.1%), LAMA + LABA/ICS (39.0%) and LABA/ICS (14.4%) were the top three inhalants. We found that 42.7% of Group A patients, 61.6% of Group B patients and 30% of Group C patients were following inappropriate therapy, especially overuse of ICS. Only 3.9% (95% CI 2.4, 5.4) of patients used oxygen therapy, and 1.8% (95% CI 1.5, 2.3) used noninvasive positive pressure ventilation at home. Among these patients, 33.2% had poor adherence. A total of 452 patients completed 1 year of follow-up. After 1 year of treatment, the lung function of FEV1/FVC decreased (P=0.001) and the mMRC score increased (P<0.001). There was no change in CAT scores (P>0.05). Conclusion: This study highlights a significant discrepancy between recommendations for managing patients with COPD in GOLD report, and in real-world clinical practice in China. Over-prescription of ICS and under-prescription of nonpharmacologic therapy were common. The adherence to treatment of patients was poor, and the real-life treatment effectiveness was unsatisfactory. More attention should be paid to the implementation of recommendations and standardized administration of therapies.

Modified and simplified clinically important deterioration: multidimensional indices of short-term disease trajectory to predict future exacerbations in patients with chronic obstructive pulmonary disease.

BACKGROUND AND AIMS: Various prediction indices based on the single time point observation have been proposed in chronic obstructive pulmonary disease (COPD), but little was known about disease trajectory as a predictor of future exacerbations. Our study explored the association between disease trajectory and future exacerbations, and validated the predictive value of the modified and simplified short-term clinically important deterioration (CID). METHODS: This study was a multicenter, prospective observational study. Patients with COPD were recruited into our study and followed up for 18 months. The modified CID (CID-C) was defined as a decrease of 100 mL in forced expiratory volume in 1 second (FEV1), or suffering exacerbations, or increase of 2 units in COPD Assessment Test (CAT) during the first 6 months follow-up. Simplified CID was defined when excluding CAT from the CID-C model. RESULTS: A total of 127 patients were enrolled in our final analysis. Compared with patients without exacerbations during the period of the 6th to the 18th month, patients with exacerbations were more likely to have frequent short-term exacerbations in the first 6 months (2.14 versus 0.21, p < 0.001). The short-term exacerbations were the best predictor for future exacerbations [odds ratio (OR): 13.25; 95% confidence interval: 5.62-34.67; p < 0.001], followed by the history of exacerbation before study entry, short-term changes in FEV1 and CAT. CID-C and Simplified CID were both significantly associated with exacerbations (OR: 7.14 and 9.74, both p < 0.001). The receiver operating characteristic curves showed that the Simplified CID had slightly better predictive capacity for future exacerbation than CID-C (0.754 versus 0.695, p = 0.02). CONCLUSION: Disease trajectory, including both the CID-C and the Simplified CID had significant predictive value for future exacerbations.The reviews of this paper are available via the supplemental material section.

Characteristics of Patients with Chronic Obstructive Pulmonary Disease Exposed to Different Environmental Risk Factors: A Large Cross-Sectional Study.

Purpose: Tobacco smoking, biomass smoke, and occupational exposure are the main risk factors for chronic obstructive pulmonary disease (COPD). The present study analyzes data on exposure to these factors in a cohort of patients with COPD and assesses their differences in demographic and clinical characteristics. Patients and Methods: The cross-sectional observational study was conducted from November 2016 to December 2019. Inclusion criteria were patients aged over 40 years old with post-bronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) <0.7. At baseline, demographic features and exposure history were recorded. Moreover, respiratory symptoms were assessed by the COPD Assessment Test (CAT) and modified Medical Research Council scale (mMRC). A generalized linear mixed model was used to adjust for potential confounders. Results: A total of 5183 patients with COPD were included in the final analysis. The results demonstrate that exposure to tobacco combined with other risk factors resulted in significantly higher CAT scores (16.0 ± 6.7 vs 15.3 ± 6.3, P = 0.003) and more severe dyspnea (patients with mMRC ≥ 2, 71.5% vs 61.6%, P < 0.001) than exposure to tobacco alone. In addition, COPD patients with biomass smoke exposure alone had higher CAT scores than patients with only tobacco or occupational exposure (17.5 ± 6.3 vs 15.3 ± 6.3, and 15.2 ± 6.3, respectively, P < 0.05 for each comparison) and were more likely to be female and older. In addition, COPD patients who suffered from occupational exposure developed more severe dyspnea than those exposed to tobacco alone (70.8% vs 61.6%, P < 0.05), as did those exposed to biomass smoke alone (74.2% vs 61.6%, P < 0.05). This difference remained strong even after adjustment for potential confounders. Conclusion: There are significant demographic and clinical differences among COPD patients with tobacco smoking, biomass smoke, and occupational exposures.

[Simple three-variable screening tool for identification of patients with obstructive sleep apnea-hypopnea syndrome in middle-aged male snorers from Guangxi region: a multi-center study].

OBJECTIVE: To evaluate the correlation between three variables of neck circumference, body mass index (BMI) and Epworth sleepiness scale (ESS) and obstructive sleep apnea-hypopnea syndrome (OSAHS) and the value of three-variable screening tool among snorers in Guangxi region. METHODS: From May 2009 to June 2014, 2 955 middle-aged consecutive patients with snoring were recruited from four hospitals of Guangxi Province. All subjects underwent polysomnography (PSG) and physical examinations including neck circumference, BMI and ESS. The diffrences of neck circumference, BMI and ESS were compared between OSAHS and non-OSAHS groups; the correlation between apnea-hypopnea index (AHI) and neck circumference, BMI and ESS were analyzed. The optimal cutoff point of three variables was selected by SPSS's Optimal Binning methods and screening score was assigned according to the Logistic regression coefficient. The recommended cutoff points were neck circumference ≥ 38.5 cm (3 points), BMI ≥ 25.7 kg/m(2) (5 points), ESS ≥ 9 points (1 point) for males and neck circumference ≥ 34.5 cm (5 points), BMI ≥ 24.5 kg/m(2) (2 points), ESS ≥ 7 points (1 points) for females. The best integral value was obtained through the receiver operating characteristic (ROC) curve. RESULTS: A total of 2 803 subjects fulfilled the study criteria. There were 2 366 males and 437 females. The average values of neck circumference, BMI and ESS were (38.7 ± 3.5) cm, (27.3 ± 3.6) kg/m(2) and (8.6 ± 5.4) score respectively. Both males and females had a positive association between AHI and neck circumference, BMI and ESS (r = 0.389, 0.485, 0.293, 0.386, 0.439 and 0.291 respectively, all P < 0.001). For males, at an integral value ≥ 6, the sensitivity was 71.4% in the diagnosis of OSAHS, specificity 65.5% and positive predictive value 91.1%. For females, at an integral value ≥ 3, the sensitivity was 73.3% in the diagnosis of OSAHS, specificity 63.6% and positive predictive value 66.3%. CONCLUSIONS: In middle-aged snorers in Guangxi, neck circumference, BMI and ESS are correlated with OSAHS. And a positive association exists between AHI and neck circumference, BMI and ESS. Simple three-variable screening tool is highly valuable for diagnosing OSAHS, especially among male snorers.