Activated non-neuronal cholinergic system correlates with non-type 2 inflammation and exacerbations in severe asthma.

BACKGROUND: Non-neuronal cholinergic system (NNCS) contributes to various inflammatory airway diseases. However, the role of NNCS in severe asthma (SA) remains largely unexplored. OBJECTIVE: To explore airway NNCS in SA. METHODS: In this prospective cohort study based on the Australasian Severe Asthma Network in a real-world setting, patients with SA (n = 52) and non-SA (n = 104) underwent clinical assessment and sputum induction. The messenger RNA (mRNA) levels of NNCS components and proinflammatory cytokines in the sputum were detected using real-time quantitative polymerase chain reaction, and the concentrations of acetylcholine (Ach)-related metabolites were evaluated using liquid chromatography coupled with tandem mass spectrometry. Asthma exacerbations were prospectively investigated during the next 12 months. The association between NNCS and future asthma exacerbations was also analyzed. RESULTS: Patients with SA were less controlled and had worse airway obstruction, a lower bronchodilator response, higher doses of inhaled corticosteroids, and more add-on treatments. The sputum mRNA levels of NNCS components, such as muscarinic receptors M1R-M5R, OCT3, VACHT, and ACHE; proinflammatory cytokines; and Ach concentration in the SA group were significantly higher than those in the non-SA group. Furthermore, most NNCS components positively correlated with non-type (T) 2 inflammatory profiles, such as sputum neutrophils, IL8, and IL1B. In addition, the mRNA levels of sputum M2R, M3R, M4R, M5R, and VACHT were independently associated with an increased risk of moderate-to-severe asthma exacerbations. CONCLUSION: This study indicated that the NNCS was significantly activated in SA, leading to elevated Ach and was associated with clinical features, non-T2 inflammation, and future exacerbations of asthma, highlighting the potential role of the NNCS in the pathogenesis of SA. CLINICAL TRIAL REGISTRATION: ChiCTR-OOC-16009529 (http://www.chictr.org.cn).

Airway Stents from Now to the Future: A Narrative Review.

Airway stent insertion is important for patients with airway stenosis. Currently, the most widely used airway stents in clinical procedures are silicone and metallic stents, which offer patients effective treatment. However, these stents composed of permanent materials need to be removed, subjecting patients to invasive manipulation once more. As a result, there is a growing demand for biodegradable airway stents. Biodegradable materials for airway stents are now available in two types: biodegradable polymers and biodegradable alloys. Polymers that include poly (l-lactic acid), poly (D, l-lactide-co-glycolide), polycaprolactone, and polydioxanone are the ultimate metabolites which are generally carbon dioxide and water. Magnesium alloys are the most often utilized metal biodegradable materials for airway stents. The stent's mechanical properties and rate of degradation vary as a result of the different materials, cutting techniques, and structural configurations. We summarized the information above from recent studies on biodegradable airway stents conducted in both animals and humans. There is great potential for clinical applications for biodegradable airway stents. They avoid damage to the trachea during removal and reduce complications to some extent. However, several significant technical difficulties slow down the development of biodegradable airway stents. The efficacy and safety of different biodegradable airway stents still need to be investigated and proved.

Clinical characteristics and predictors of pulmonary hypertension in chronic obstructive pulmonary disease at different altitudes.

BACKGROUND: Pulmonary hypertension (PH) is a common complication in patients with chronic obstructive pulmonary disease (COPD) and is closely associated with poor prognosis. However, studies on the predictors of PH in COPD patients are limited, especially in populations living at high altitude (HA). OBJECTIVES: To investigate the differences in the clinical characteristics and predictors of patients with COPD/COPD and PH (COPD-PH) from low altitude (LA, 600 m) and HA (2200 m). METHODS: We performed a cross-sectional survey of 228 COPD patients of Han nationality admitted to the respiratory department of Qinghai People's Hospital (N = 113) and West China Hospital of Sichuan University (N = 115) between March 2019 and June 2021. PH was defined as a pulmonary arterial systolic pressure (PASP) > 36 mmHg measured using transthoracic echocardiography (TTE). RESULTS: The proportion of PH in COPD patients living at HA was higher than that in patients living at LA (60.2% vs. 31.3%). COPD-PH patients from HA showed significantly different in baseline characteristics, laboratory tests and pulmonary function test. Multivariate logistic regression analysis indicated that the predictors of PH in COPD patients were different between the HA and LA groups. CONCLUSIONS: The COPD patients living at HA had a higher proportion of PH than those living at LA. At LA, increased B-type natriuretic peptide (BNP) and direct bilirubin (DB) were predictors for PH in COPD patients. However, at HA, increased DB was a predictor of PH in COPD patients.

Monitoring small airway dysfunction in connective tissue disease-related interstitial lung disease: a retrospective and prospective study.

BACKGROUND: Small airway dysfunction (SAD), a hallmark of early lung function abnormality, is a major component of several chronic respiratory disorders. The role of SAD in patients with connective tissue disease-related interstitial lung disease (CTD-ILD) has not been explored. METHODS: We conducted a two-parts (retrospective and prospective) study to collect pulmonary function tests from CTD-ILD patients. SAD was defined as at least two of the three measures (MMEF, FEF 50%, and FEF 75%) must be 65% of predicted values. Spearman correlation coefficient was used to evaluate association between SAD and other pulmonary function parameters. Mixed effects regression modeling analysis was used to assess response to treatment. RESULTS: CTD-ILD patients with SAD and without SAD were compared in this study. In the retrospective study, pulmonary function tests (PFTs) from 491 CTD-ILD patients were evaluated, SAD were identified in 233 (47.5%). CTD-ILD patients with SAD were less smokers (17.6% vs. 27.9%, p = 0.007) and more females (74.3% vs. 64.0%, p = 0.015) than those without SAD. CTD-ILD patients with SAD had lower vital capacity (% predicted FVC, 70.4 ± 18.3 vs. 80.0 ± 20.9, p < 0.001) and lower diffusion capacity (% predicted DLCO, 58.8 ± 19.7 vs. 63.8 ± 22.1, p = 0.011) than those without SAD. Among 87 CTD-ILD patients prospectively enrolled, significant improvement in % predicted FVC was observed at 12-months follow-up (6.37 ± 1.53, p < 0.001 in patients with SAD; 5.13 ± 1.53, p = 0.002 in patients without SAD), but not in diffusion capacity and SAD parameters. CONCLUSION: In our cohort, about half of CTD-ILD patients have SAD, which is less frequent in smokers and more common in female patients. CTD-ILD patients with SAD have worse pulmonary function compared to those without SAD. Improvement of FVC but no improvement of SAD was observed in CTD-ILD patients after treatment.

Transcriptomic profiles of age-related genes in female trachea and bronchus.

Background: Studies demonstrated that age-related cellular and functional changes of airway significantly contribute to the pathogenesis of many airway diseases. However, our understanding on the age-related molecular alterations of human airway remains inadequate. Methods: Airway (trachea and bronchus) brushing specimens were collected from 14 healthy, female non-smokers with ages ranging from 20 to 60 years. Bulk RNA sequencing was performed on all the specimens (n = 28). Airway cell types and their relative proportions were estimated using CIBERSORTx. The cell type proportions were compared between the younger (age 20-40) and elder group (age 40-60) in the trachea and bronchus respectively. The linear association between cell type proportion and age was assessed using the Pearson correlation coefficient. Differentially expressed genes (DEGs) between the two age groups were identified using DESeq2. Three kinds of enrichment analysis of the age-related DEGs were performed, including Gene ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and disease enrichment analysis. Results: Sixteen and thirteen cell types were separately identified in tracheal and bronchial brushings, with the airway epithelial cells (including suprabasal, submucosal gland (SMG) goblet, serous, secretory, multiciliated, cycling.basal, basal cells) accounting for 85.1% in the trachea and 92.5% in the bronchus. The lymphatic cell and NK cells had a higher abundance ratio in the trachea, compared with the bronchus. The proportion of basal cells was negatively related to age both in the trachea and bronchus. Thirty-one and fifty-two age-related DEGs (p < 0.1) were identified in the trachea and bronchus, respectively. Among them, five common DEGs (CXCL2, CXCL8, TCIM, P4HA3, AQP10) were identified. Pathway enrichment analysis showed both tracheal and bronchial age-related DEGs were primarily involved in immune regulatory signaling pathways (TNF, NF-kappa B, IL-17 et al.). Disease enrichment analysis suggested that tracheal age-related DEGs significantly related to asthmatic pulmonary eosinophilia, and chronic airflow obstruction et al., and that bronchial age-related DEGs were enriched in airflow obstruction, bronchiectasis, pulmonary emphysema, and low respiratory tract infection et al. Conclusion: We found the proportion of basal cells decreased with age in both the trachea and bronchus, suggesting a weakening of their self-renew ability with age. We identified transcriptomic signature genes associated with the early aging process of the human trachea and bronchus, and provided evidence to support that changes in their immune regulatory function may play critical roles in age-related airway diseases.

Reduced Skeletal Muscle Mass Is Associated with an Increased Risk of Asthma Control and Exacerbation.

BACKGROUND: Skeletal muscle mass (SMM) has been suggested to be associated with multiple health-related outcomes. However, the potential influence of SMM on asthma has not been largely explored. OBJECTIVE: To study the association between SMM and clinical features of asthma, including asthma control and exacerbation, and to construct a model based on SMM to predict the risk of asthma exacerbation (AEx). METHODS: In this prospective cohort study, we consecutively recruited patients with asthma (n = 334), classified as the SMM Normal group (n = 223), SMM Low group (n = 88), and SMM High group (n = 23). We investigated the association between SMM and clinical asthma characteristics and explored the association between SMM and asthma control and AEx within a 12-month follow-up period. Based on SMM, an exacerbation prediction model was developed, and the overall performance was externally validated in an independent cohort (n = 157). RESULTS: Compared with the SMM Normal group, SMM Low group exhibited more airway obstruction and worse asthma control, while SMM High group had a reduced eosinophil percentage in induced sputum. Furthermore, SMM Low group was at a significantly increased risk of moderate-to-severe exacerbation compared with the SMM Normal group (relative risk adjusted 2.02 [95% confidence interval (CI), 1.35-2.68]; p = 0.002). In addition, a model involving SMM was developed which predicted AEx (area under the curve: 0.750, 95% CI: 0.691-0.810). CONCLUSIONS: Low SMM was an independent risk factor for future AEx. Furthermore, a model involving SMM for predicting the risk of AEx in patients with asthma indicated that assessment of SMM has potential clinical implications for asthma management.

Efficacy and Safety of JAK Inhibitors for Rheumatoid Arthritis: A Meta-Analysis.

Background: More and more trials have been conducted. We aimed to assess the efficacy and safety of different JAKinibs in RA. Methods: A systematic search of randomized controlled trials (RCTs) with JAKinib treatment in RA published in the Medline, Embase, and Cochrane databases up to May 2021 was performed. Results: 37 trials involving 15,174 patients were identified. Pooled analysis revealed that JAKinibs were associated with significant therapeutic improvement in RA patients as determined by ACR20 (RR = 2.03, 95% CI: 1.85 to 2.28) and HAQ-DI (MD = −0.31, 95% CI: −0.33 to −0.28) over placebo. Compared to placebo, JAKinib treatment was also associated with more adverse events (RR = 1.10, p < 0.001; RR = 1.29, p < 0.001; RR = 1.59, p = 0.02). Baricitinib and upadacitinib were related to more frequent adverse events (RR = 1.10; 95% CI: 1.01, 1.21; RR = 1.19; 95% CI: 1.11, 1.28) and infection (RR = 1.22; 95% CI: 1.09, 1.37; RR = 1.38; 95% CI: 1.22, 1.56), whereas only baricitinib was associated with more herpes zoster (RR = 3.15; 95% CI: 1.19, 8.33). Conclusions: JAKinibs were superior to placebo for improving signs, symptoms, and health-related quality of life in RA patients at short term, whereas the overall risk of adverse events and infections were greater with baricitinib and upadacitinib, and a higher risk of herpes zoster was only associated with baricitinib. More trials are needed to investigate the long-term safety.

Association between Dietary Anthocyanidins and Risk of Lung Cancer.

Background: Anthocyanidins are a kind of water-soluble flavonoids widely found in flowers and fruits of many plants. Although the beneficial effect of anthocyanidins in cancer prevention has been discussed, the value of anthocyanidins in lung cancer prevention requires further investigation. In this study, we aimed to explore the role of dietary anthocyanidins in the prevention of lung cancer in population-based prospective studies. Methods: Data of participants in this study were collected from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated in Cox proportional hazards regression for the association of dietary anthocyanidins and lung cancer risk. The dose-response relationship was explored between total anthocyanidins and the incidence of lung cancer. Results: A total of 97,993 participants were included in this study. The calculated HRs showed a trend that a higher quartile of total anthocyanidins indicated lower risk of lung cancer after adjusting for covariates (HRQ4vsQ1: 0.63; 95% CI: 0.55,0.73; p for trend < 0.001). A non-linear association between total anthocyanidins and lung cancer risk was found in the restricted cubic spline model. Conclusion: A protective association between dietary anthocyanidins and risk of lung cancer in Americans was investigated.

Association Between Diabetes Risk Reduction Diet and Lung Cancer Risk in 98,159 Participants: Results From a Prospective Study.

Purpose: To evaluate the association between diabetes risk reduction diet (DRRD) score and the risk of lung cancer in a large population. Methods: Data of participants in this study were collected from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated in the Cox proportional hazards regression model for the association of DRRD score and lung cancer incidence in all included participants. Prespecified subgroup analyses were performed to evaluate whether the observed association was modified by age, sex, BMI, race/ethnicity, family history of lung cancer, smoking status and history of diabetes. Results: A total of 98,159 participants were included in this study. The mean (SD) age of the study participants cohort at baseline was 65.5 (5.73) years old. The mean (SD) follow-up time was 8.83 (1.96) years. The mean (SD) score of DRRD was 26.82 (5.19), and ranged from 20.47 (2.3) to 33.65 (2.42) from the lowest quartile to the highest quartile of the DRRD score, inferring the possibility of highest through the lowest risk of type 2 diabetes. The calculated HRs showed there was a trend that higher quartile indicated lower risk of lung cancer after adjusted for covariates (HRQ4vsQ1: 0.85; 95% CI:0.73,0.98; p for trend =0.036). The inverse trend between higher DRRD score and the risk of squamous cell carcinoma was more evident (HRQ4vsQ1: 0.50; 95% CI:0.34,0.73; p for trend =0.002). The inverse association between DRRD score and the incidence of lung cancer was more pronounced in participants who had a clear family history of lung cancer (p for interaction=0.016). Conclusion: A protective association between DRRD score and risk of lung cancer is obtained. People are encouraged to adhere to higher DRRD score in their daily diet. Further studies should be conducted to confirm the result and explore the mechanism.

Reticulation Is a Risk Factor of Progressive Subpleural Nonfibrotic Interstitial Lung Abnormalities.

Rationale: Interstitial lung abnormalities (ILAs) are being increasingly identified in clinical practice. In particular, for subpleural nonfibrotic ILAs, the risk of progression over time and the risk factors for progressive behavior are still largely unknown. Objectives: To determine the age band prevalence of ILAs and the risk of radiological progression of subpleural nonfibrotic ILAs over time in a large health checkup population and to identify how reticulation contributes to the risk of radiological progression. Methods: On the basis of the ILAs definition by the Fleischner Society, low-dose chest computed tomography images from the community-dwelling population who have undergone health checkups were evaluated for ILAs. Multivariable logistic regression was used to assess the risk of radiological progression. Measurements and Main Results: Among 155,539 individuals, 3,300 (2.1%) were confirmed to have ILAs: the vast majority (81.7%) were defined as subpleural nonfibrotic ILAs. The prevalence of ILAs increased linearly with age (P for trend < 0.0001). Of 454 individuals with subpleural nonfibrotic ILAs, 198 (43.6%) had radiological progression over 4 years. The presence of reticulation on initial imaging was an independent predictor of radiological progression (odds ratio, 1.9; 95% confidence interval, 1.2-3.0; P = 0.0040). No difference in radiological progression was identified between subpleural nonfibrotic ILAs with extensive reticulation and subpleural fibrotic ILAs (73.0% vs. 68.8%; P = 0.7626). Conclusions: The prevalence of ILAs increases linearly with age. Nearly half of subpleural nonfibrotic ILAs progress radiologically over 4 years. The presence of reticulation is a risk factor for radiological progression. Subpleural nonfibrotic ILAs with extensive reticulation are likely to be a feature of subpleural fibrotic ILAs.

Quantitative evaluation of disease severity in connective tissue disease-associated interstitial lung disease by dual-energy computed tomography.

BACKGROUND: High-resolution computed tomography (HRCT) is recommended diagnosing and monitoring connective tissue disease-associated interstitial lung disease (CTD-ILD). Quantitative computed tomography has the potential to precisely assess the radiological severity of CTD-ILD, but has still been under study. OBJECTIVE: To investigate whether dual-energy computed tomography (DECT), a novel quantitative technique, can be used for quantitative severity assessment in CTD-ILD. METHODS: This cross sectional study recruited adult CTD-ILD patients who underwent DECT scans from the ICE study between October 2019 and November 2021. DECT parameters, including effective atomic number (Zeff), lung (lobe) volume, and monochromatic CT number (MCTN) of each lung lobe, were evaluated. CTD-ILD was classified into extensive CTD-ILD and limited CTD-ILD by staging algorithm using combined forced vital capacity (FVC)%predicted and total extent of ILD (TEI) on CT. Dyspnea, cough, and life quality were scored by Borg dyspnea score, Leicester cough questionnaire (LCQ), and short-form 36 health survey questionnaire (SF-36), respectively. RESULTS: There was a total of 147 patients with DECT scans enrolled. Higher Zeff value (3.104 vs 2.256, p < 0.001), higher MCTN (- 722.87 HU vs - 802.20 HU, p < 0.001), and lower lung volume (2309.51cm3 vs 3475.21cm3, p < 0.001) were found in extensive CTD-ILD compared with limited CTD-ILD. DECT parameters had significant moderate correlations with FVC%predicted (|r|= 0.542-0.667, p < 0.01), DLCO%predicted (|r|= 0.371-0.427, p < 0.01), and TEI (|r|= 0.485-0.742, p < 0.01). Receiver operating characteristic (ROC) analysis indicated MCTN averaged over the whole lung had the best performance for extensive CTD-ILD discrimination (AUC = 0.901, cut-off: - 762.30 HU, p < 0.001), with a sensitivity of 82.1% and a specificity of 85.4%. The Zeff value was the independent risk factor for dyspnea (OR = 3.644, 95% CI: 1.846-7.192, p < 0.001) and cough (OR = 3.101, 95% CI: 1.528-6.294, p = 0.002), and lung volume significantly contributed to the mental component summary (MCS) in SF-36 (standardized ß = 0.198, p < 0.05). CONCLUSIONS: DECT can be applied to evaluate the severity of CTD-ILD.

PRMT7 targets of Foxm1 controls alveolar myofibroblast proliferation and differentiation during alveologenesis.

Although aberrant alveolar myofibroblasts (AMYFs) proliferation and differentiation are often associated with abnormal lung development and diseases, such as bronchopulmonary dysplasia (BPD), chronic obstructive pulmonary disease (COPD), and idiopathic pulmonary fibrosis (IPF), epigenetic mechanisms regulating proliferation and differentiation of AMYFs remain poorly understood. Protein arginine methyltransferase 7 (PRMT7) is the only reported type III enzyme responsible for monomethylation of arginine residue on both histone and nonhistone substrates. Here we provide evidence for PRMT7's function in regulating AMYFs proliferation and differentiation during lung alveologenesis. In PRMT7-deficient mice, we found reduced AMYFs proliferation and differentiation, abnormal elastin deposition, and failure of alveolar septum formation. We further shown that oncogene forkhead box M1 (Foxm1) is a direct target of PRMT7 and that PRMT7-catalyzed monomethylation at histone H4 arginine 3 (H4R3me1) directly associate with chromatin of Foxm1 to activate its transcription, and thereby regulate of cell cycle-related genes to inhibit AMYFs proliferation and differentiation. Overexpression of Foxm1 in isolated myofibroblasts (MYFs) significantly rescued PRMT7-deficiency-induced cell proliferation and differentiation defects. Thus, our results reveal a novel epigenetic mechanism through which PRMT7-mediated histone arginine monomethylation activates Foxm1 transcriptional expression to regulate AMYFs proliferation and differentiation during lung alveologenesis and may represent a potential target for intervention in pulmonary diseases.

Claudin18 associated with corticosteroid-induced expression of surfactant proteins in pulmonary epithelial cells.

OBJECTIVE: The present study was undertaken to test the hypothesis that if Cldn18 is associated with lung maturation and play a key role in the corticosteroid-induced expression of surfactant proteins. METHODS: Mouse embryonic lung tissue at different developmental stages (E14.5, E16.5 and E18.5) was collected to detect the temporal-spatial expression of Cldn18 by Western blot and immunofluorescence staining. Dexamethasone + cAMP + isobutylmethylxanthine (DCI), a commonly used agent for inducing maturation of alveolar epithelial cell in vitro, was used to mimic the roles of corticosteroid. Mouse alveolar epithelial cell line MLE12 treated with or without DCI were harvested, expression of Cldn18 and surfactant proteins were assessed by real-time RT-PCR. For Si-RNA experiments, MLE-12 was transfected with control siRNA or Cldn18 siRNA for 24 h before DCI treatment. Expression of Cldn18 and surfactant proteins was assessed by real-time RT-PCR. RESULTS: Expression of Cldn18 was detected in peripheral lung epithelial cells, and increased expression was detected from E14.5 to E18.5 during lung development. Expression of Cldn18 and surfactants (SPA, SPB and SPC) were significantly induced in MLE12 after DCI treatment. Silencing of Cldn18 effectively suppressed the DCI-induced expression of SPB and SPC but not SPA. CONCLUSION: Our results demonstrated that expression of Cldn18 is associated with peripheral lung epithelial cell maturation and play a key role in the corticosteroid-induced expression of surfactant proteins.

Increased serum Th2 chemokine levels are associated with bronchopulmonary dysplasia in premature infants.

Bronchopulmonary dysplasia (BPD) is one of the most common chronic inflammatory lung disease of premature infants, with serious short- and long-term consequences. Early identification of premature infants at risk of BPD is critical to preventing the pathogenesis of disease. Thus, in the present study, we recruited 126 premature infants, collected peripheral blood samples at different time points during early life, and measured the concentration of Th1 (MCP-1, IP-10, and MIG) and Th2 (eotaxin-1, eotaxin-2, and MCP-4) chemokines in serum. We found serum eotaxin-2 levels were significantly higher in the BPD group than in the non-BPD group on day 1 [1662 pg/ml vs. 1221 pg/ml, P < 0.05], day 7 [1533 pg/ml vs. 1089 pg/ml, P < 0.05], and day 14 [1246 pg/ml vs. 704 pg/ml, P < 0.05] after birth, and serum MCP-4 levels were also significantly higher in the BPD group than in the non-BPD group on day 1 [186 pg/ml vs. 128 pg/ml, P < 0.05], day 7 [199 pg/ml vs. 101 pg/ml, P < 0.05], and day 14 [238 pg/ml vs. 106 pg/ml, P < 0.05] of life.Conclusions: Increased levels of Th2 chemokines, eotaxin-2, and MCP-4, are associated with BPD in premature infants. What is Known: • The pathogenesis of BPD is multifactorial and it is difficult to predict and prevent. • Previous studies have demonstrated that inflammation plays a major role in the pathogenesis of BPD. What is New: • Increased Th2 chemokines, eotaxin-2 and MCP-4, were associated with BPD in premature infants. • Abnormal Th1/Th2 response in early life maybe associated with the subsequent development of BPD, which provide a new insight to understand the pathogenesis of the disease.

Histone arginine methylation by Prmt5 is required for lung branching morphogenesis through repression of BMP signaling.

Branching morphogenesis is essential for the successful development of a functional lung to accomplish its gas exchange function. Although many studies have highlighted requirements for the bone morphogenetic protein (BMP) signaling pathway during branching morphogenesis, little is known about how BMP signaling is regulated. Here, we report that the protein arginine methyltransferase 5 (Prmt5) and symmetric dimethylation at histone H4 arginine 3 (H4R3sme2) directly associate with chromatin of Bmp4 to suppress its transcription. Inactivation of Prmt5 in the lung epithelium results in halted branching morphogenesis, altered epithelial cell differentiation and neonatal lethality. These defects are accompanied by increased apoptosis and reduced proliferation of lung epithelium, as a consequence of elevated canonical BMP-Smad1/5/9 signaling. Inhibition of BMP signaling by Noggin rescues the lung branching defects of Prmt5 mutant in vitro Taken together, our results identify a novel mechanism through which Prmt5-mediated histone arginine methylation represses canonical BMP signaling to regulate lung branching morphogenesis.

Elevated Krüppel-like factor 5 expression in spatiotemporal mouse lungs is similar to human congenital cystic adenomatoid malformation of the lungs.

Objective The study aimed to investigate the role of high Krüppel-like factor 5 (KLF5) expression on the pathogenesis of congenital cystic adenomatoid malformation of the lungs (CCAML) in mice. Methods A mouse model of high KLF5 expression in the lungs was established. KLF5 expression and the pulmonary lumen diameter were examined by immunohistochemistry to determine a successful model. Basement membrane damage and activity of matrix metalloproteinase-9 (MMP-9) were examined. After an adenovirus carrying KLF5 gene transfection in lung adenocarcinoma (H441) was created, changes in expression and activity of MMP-9 were determined. Results In a mouse model with high KLF5 expression, the pulmonary lumen was markedly enlarged, indicating establishment of CCAML. The basement membrane was degraded, and MMP-9 activity was significantly higher in the model group compared with the control group. Moreover, mice in a cellular model after transfection also showed higher MMP-9 activity than did controls. Conclusion High KLF5 expression may play a pivotal role in the pathogenesis of CCAML, partly through regulating the activity of MMP-9.

WITHDRAWN: KLF5 promoted symmetric cell division in KRT5 positive keratinocytes through suppression of Notch1 expression.

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[Combined effect of gestational age and birth weight on metabolites related to inherited metabolic diseases in neonates].

OBJECTIVE: To study the combined effect of gestational age and birth weight on metabolites related to inherited metabolic diseases (IMD). METHODS: A total of 3 381 samples ruled out of IMD by follow-up were randomly selected from 38 931 newborns who participated in the neonatal IMD screening during 2014-2016. The 3 381 neonates were categorized into seven groups according to their gestational age and birth weight: extremely preterm appropriate-for-gestational age (AGA) group (n=12), preterm small-for-gestational age (SGA) group (n=18), preterm AGA group (n=219), preterm large-for-gestational age (LGA) group (n=18), full-term SGA group (n=206), full-term AGA group (n=2 677), and full-term LGA group (n=231). Heel blood samples were collected from each group on postnatal days 3-7 after adequate breastfeeding. Levels of 17 key IMD-related metabolic indices in dried blood spots were measured using tandem mass spectrometry. Spearman′s correlation analysis was used to investigate the relationships between 17 IMD-related metabolic indices and their influencing factors, while covariance analysis was used to compare the metabolic indices between these groups. RESULTS: After adjusting the influencing factors such as physiological and pathological status, compared with the full-term AGA group, the extremely preterm AGA, preterm SGA, and preterm AGA groups had significantly reduced levels of leucine\isoleucine\hydroxyproline and valine (P<0.05); the preterm AGA group had a significantly decreased ornithine level (P<0.05); the extremely preterm AGA and preterm AGA groups had a significantly reduced proline level (P<0.05). Besides, the phenylalanine level in the extremely preterm AGA and preterm AGA groups, the methionine level in the preterm SGA group, and the tyrosine level in the preterm AGA group all significantly increased (P<0.05). The increased levels of free carnitine, acetylcarnitine, and propionylcarnitine were found in the preterm SGA and preterm AGA groups. The oleylcarnitine level also significantly increased in the preterm SGA group (P<0.05). Most carnitine indices showed significant differences between the SGA group and the AGA/LGA group in both preterm and full-term infants (P<0.05). CONCLUSIONS: Low gestational age and low birth weight may result in abnormal results in IMD screening. Therefore, gestational age and birth weight should be considered to comprehensively judge the abnormal results in IMD screening.