MEOX1 triggers myofibroblast apoptosis resistance, contributing to pulmonary fibrosis in mice.

The apoptosis resistance of myofibroblasts is a hallmark in the irreversible progression of pulmonary fibrosis (PF). While the underlying molecular mechanism remains elusive. In this study, we unveiled a previously unrecognized mechanism underlying myofibroblast apoptosis resistance during PF. Our investigation revealed heightened expression of mesenchyme homeobox 1 (MEOX1) in the lungs of idiopathic pulmonary fibrosis (IPF) patients and bleomycin-induced PF mice. Silencing MEOX1 significantly attenuated PF progression in mice. In vitro, we found a notable increase in MEOX1 expression in transforming growth factor-ß1 (TGF-ß1)-induced myofibroblasts. Silencing MEOX1 enhanced apoptosis of myofibroblasts. Mechanistically, we identified G-protein signaling pathway regulatory factor 4 (RGS4) as a critical downstream target of MEOX1, as predicted by bioinformatics analysis. MEOX1 enhanced apoptosis resistance by upregulating RGS4 expression in myofibroblasts. In conclusion, our study highlights MEOX1 as a promising therapeutic target for protecting against PF by modulating myofibroblast apoptosis resistance.

CGRP is essential for protection against alveolar epithelial cell necroptosis by activating the AMPK/L-OPA1 signaling pathway during acute lung injury.

Alveolar epithelial cell (AEC) necroptosis is critical to disrupt the alveolar barrier and provoke acute lung injury (ALI). Here, we define calcitonin gene-related peptide (CGRP), the most abundant endogenous neuropeptide in the lung, as a novel modulator of AEC necroptosis in lipopolysaccharide (LPS)-induced ALI. Upon LPS-induced ALI, overexpression of Cgrp significantly mitigates the inflammatory response, alleviates lung tissue damage, and decreases AEC necroptosis. Similarly, CGRP alleviated AEC necroptosis under the LPS challenge in vitro. Previously, we identified that long optic atrophy 1 (L-OPA1) deficiency mediates mitochondrial fragmentation, leading to AEC necroptosis. In this study, we discovered that CGRP positively regulated mitochondrial fusion through stabilizing L-OPA1. Mechanistically, we elucidate that CGRP activates AMP-activated protein kinase (AMPK). Furthermore, the blockade of AMPK compromised the protective effect of CGRP against AEC necroptosis following the LPS challenge. Our study suggests that CRGP-mediated activation of the AMPK/L-OPA1 axis may have potent therapeutic benefits for patients with ALI or other diseases with necroptosis.

The Role of Mitochondrial Quality Control in Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity, mortality, and health care use worldwide with heterogeneous pathogenesis. Mitochondria, the powerhouses of cells responsible for oxidative phosphorylation and energy production, play essential roles in intracellular material metabolism, natural immunity, and cell death regulation. Therefore, it is crucial to address the urgent need for fine-tuning the regulation of mitochondrial quality to combat COPD effectively. Mitochondrial quality control (MQC) mainly refers to the selective removal of damaged or aging mitochondria and the generation of new mitochondria, which involves mitochondrial biogenesis, mitochondrial dynamics, mitophagy, etc. Mounting evidence suggests that mitochondrial dysfunction is a crucial contributor to the development and progression of COPD. This article mainly reviews the effects of MQC on COPD as well as their specific regulatory mechanisms. Finally, the therapeutic approaches of COPD via MQC are also illustrated.

COX-2/sEH-Mediated Macrophage Activation Is a Target for Pulmonary Protection in Mouse Models of Chronic Obstructive Pulmonary Disease.

Effective inhibition of macrophage activation is critical for resolving inflammation and restoring pulmonary function in patients with chronic obstructive pulmonary disease (COPD). In this study, we identified the dual-enhanced cyclooxygenase-2 (COX-2)/soluble epoxide hydrolase (sEH) as a novel regulator of macrophage activation in COPD. Both COX-2 and sEH were found to be increased in patients and mice with COPD and in macrophages exposed to cigarette smoke extract. Pharmacological reduction of the COX-2 and sEH by 4-(5-phenyl-3-{3-[3-(4-trifluoromethylphenyl)-ureido]-propyl}-pyrazol-1-yl)-benzenesulfonamide (PTUPB) effectively prevented macrophage activation, downregulated inflammation-related genes, and reduced lung injury, thereby improving respiratory function in a mouse model of COPD induced by cigarette smoke and lipopolysaccharide. Mechanistically, enhanced COX-2/sEH triggered the activation of the NACHT, LRR, and PYD domains-containing protein 3 inflammasome, leading to the cleavage of pro-IL-1ß into its active form in macrophages and amplifying inflammatory responses. These findings demonstrate that targeting COX-2/sEH-mediated macrophage activation may be a promising therapeutic strategy for COPD. Importantly, our data support the potential use of the dual COX-2 and sEH inhibitor PTUPB as a therapeutic drug for the treatment of COPD.

Full-space metasurfaces for independent manipulation of transmission and reflection.

In recent years, beam manipulation using metasurfaces has evolved from being limited to either a transmission or reflection space to encompassing a full space. However, existing methods still inevitably require complex systems and are unable to achieve continuous and arbitrary phase manipulation. Here, one type of a bilayer metasurface is proposed to simultaneously manipulate reflection and transmission phases continuously and independently, which also makes the optical system more compact without requiring any analyzers and enhances the degree of freedom for full-space beam manipulation. As a proof-of-concept demonstration, one device is designed to show different holograms in transmission and reflection spaces. Additionally, the Dammann grating designed in the reflection hologram increases the information capacity. The proposed method may pave the way toward achieving a variety of applications such as multi-channel beam manipulation and multifunctional optical devices.

TREM-1 triggers necroptosis of macrophages through mTOR-dependent mitochondrial fission during acute lung injury.

BACKGROUND: Necroptosis of macrophages is a necessary element in reinforcing intrapulmonary inflammation during acute lung injury (ALI). However, the molecular mechanism that sparks macrophage necroptosis is still unclear. Triggering receptor expressed on myeloid cells-1 (TREM-1) is a pattern recognition receptor expressed broadly on monocytes/macrophages. The influence of TREM-1 on the destiny of macrophages in ALI requires further investigation. METHODS: TREM-1 decoy receptor LR12 was used to evaluate whether the TREM-1 activation induced necroptosis of macrophages in lipopolysaccharide (LPS)-induced ALI in mice. Then we used an agonist anti-TREM-1 Ab (Mab1187) to activate TREM-1 in vitro. Macrophages were treated with GSK872 (a RIPK3 inhibitor), Mdivi-1 (a DRP1 inhibitor), or Rapamycin (an mTOR inhibitor) to investigate whether TREM-1 could induce necroptosis in macrophages, and the mechanism of this process. RESULTS: We first observed that the blockade of TREM-1 attenuated alveolar macrophage (AlvMs) necroptosis in mice with LPS-induced ALI. In vitro, TREM-1 activation induced necroptosis of macrophages. mTOR has been previously linked to macrophage polarization and migration. We discovered that mTOR had a previously unrecognized function in modulating TREM-1-mediated mitochondrial fission, mitophagy, and necroptosis. Moreover, TREM-1 activation promoted DRP1Ser616 phosphorylation through mTOR signaling, which in turn caused surplus mitochondrial fission-mediated necroptosis of macrophages, consequently exacerbating ALI. CONCLUSION: In this study, we reported that TREM-1 acted as a necroptotic stimulus of AlvMs, fueling inflammation and aggravating ALI. We also provided compelling evidence suggesting that mTOR-dependent mitochondrial fission is the underpinning of TREM-1-triggered necroptosis and inflammation. Therefore, regulation of necroptosis by targeting TREM-1 may provide a new therapeutic target for ALI in the future.

The impact of impaired sleep quality on symptom change and future exacerbation of chronic obstructive pulmonary disease.

PURPOSE: Study the impact of impaired sleep quality on symptom change and future exacerbation of chronic obstructive pulmonary disease (COPD) patients. METHODS: This was a prospective study. Patients with COPD were recruited into the study and followed up for one year. Pittsburgh sleep quality index (PSQI) was collected at baseline. Symptom change was assessed with Minimum clinically important difference (MCID) in COPD Assessment Test (CAT) at 6-month visit, which is an indicator to assess symptom improvement. Exacerbation was recorded during the one-year visit. PSQI score > 5 was defined as poor sleep quality, whereas PSQI score ≤ 5 was defined as good sleep quality. MCID was defined as attaining a CAT decrease ≥ 2. RESULTS: A total of 461 patients were enrolled for final analysis. Two hundred twenty-eight (49.4%) patients had poor sleep quality. Overall, 224 (48.6%) patients attained MCID at 6-month visit and the incidence of exacerbation during the one-year visit was 39.3%. Fewer patients with impaired sleep quality achieved MCID than patients with good sleep quality. Good sleepers were significantly more likely to attain MCID (OR: 3.112, p < 0.001) than poor sleepers. Fewer poor sleepers in GOLD A and D groups attained MCID with ICS/LABA, and fewer poor sleepers in the GOLD D group attained MCID with ICS/LABA/LAMA than good sleepers. Poor sleep quality was a greater risk factor of future exacerbation in Cox regression analysis. The ROC curves showed that PSQI score had a predictive capacity for future exacerbation. More patients with poor sleep quality experienced future exacerbation in GOLD B and D group with treatment of ICS/LABA/LAMA compared to good sleepers. CONCLUSIONS: COPD patients with impaired sleep quality were less likely to achieve symptom improvement and were at increased risk of future exacerbation compared to patients with good sleep quality. Besides, sleep disturbance may affect the symptom improvement and future exacerbation of patients with different inhaled medication or in different GOLD groups.

Fn14 exacerbates acute lung injury by activating the NLRP3 inflammasome in mice.

BACKGROUND: Uncontrolled inflammation is an important factor in the occurrence and development of acute lung injury (ALI). Fibroblast growth factor-inducible 14 (Fn14), a plasma membrane-anchored receptor, takes part in the pathological process of a variety of acute and chronic inflammatory diseases. However, the role of Fn14 in ALI has not yet been elucidated. This study aimed to investigate whether the activation of Fn14 exacerbated lipopolysaccharide (LPS)-induced ALI in mice. METHODS: In vivo, ALI was induced by intratracheal LPS-challenge combined with/without Fn14 receptor blocker aurintricarboxylic acid (ATA) treatment in C57BL/6J mice. Following LPS administration, the survival rate, lung tissue injury, inflammatory cell infiltration, inflammatory factor secretion, oxidative stress, and NLRP3 inflammasome activation were assessed. In vitro, primary murine macrophages were used to evaluate the underlying mechanism by which Fn14 activated the NLRP3 inflammasome. Lentivirus was used to silence Fn14 to observe its effect on the activation of NLRP3 inflammasome in macrophages. RESULTS: In this study, we found that Fn14 expression was significantly increased in the lungs of LPS-induced ALI mice. The inhibition of Fn14 with ATA downregulated the protein expression of Fn14 in the lungs and improved the survival rate of mice receiving a lethal dose of LPS. ATA also attenuated lung tissue damage by decreasing the infiltration of macrophages and neutrophils, reducing inflammation, and suppressing oxidative stress. Importantly, we found that ATA strongly inhibited the activation of NLRP3 inflammasome in the lungs of ALI mice. Furthermore, in vitro, TWEAK, a natural ligand of Fn14, amplified the activation of NLRP3 inflammasome in the primary murine macrophage. By contrast, inhibition of Fn14 with shRNA decreased the expression of Fn14, NLRP3, Caspase-1 p10, and Caspase-1 p20, and the production of IL-1ß and IL-18. Furthermore, the activation of Fn14 promoted the production of reactive oxygen species and inhibited the activation of Nrf2-HO-1 in activated macrophages. CONCLUSIONS: Our study first reports that the activation of Fn14 aggravates ALI by amplifying the activation of NLRP3 inflammasome. Therefore, blocking Fn14 may be a potential way to treat ALI.

Design method of a wide-angle AR display with a single-layer two-dimensional pupil expansion geometrical waveguide.

Waveguide near-eye displays (NEDs) consist of a planar waveguide combiner and a coupling-in projection system. A two-dimensional geometrical waveguide (TDGW) can achieve an ultra-thin, large exit pupil diameter (XPD), wide-angle NED. The design method of a single-layer TDGW is presented and discussed in detail in this paper. A high-precision processing technology that can effectively guarantee the parallelism accuracy is also presented. A miniature coupling-in projection optics is designed with a catadioptric structure and integrated with the waveguide accordingly. Finally, a TDGW with a thickness of 1.75 mm is designed and analyzed. The results show that the stray light over the normal light is less than 0.5%, and the illuminance uniformity is well optimized. The field of view is up to 55°, and the XPD exceeds 12mm×10mm at an eye relief (ERF) of 18 mm. A proof-of-concept prototype was fabricated and demonstrated.

Epoxyeicosatrienoic acids inhibit the activation of NLRP3 inflammasome in murine macrophages.

Epoxyeicosatrienoic acids (EETs) derived from arachidonic acid exert anti-inflammation effects. We have reported that blocking the degradation of EETs with a soluble epoxide hydrolase (sEH) inhibitor protects mice from lipopolysaccharide (LPS)-induced acute lung injury (ALI). The underlying mechanisms remain essential questions. In this study, we investigated the effects of EETs on the activation of nucleotide-binding domain leucine-rich repeat-containing receptor, pyrin domain-containing-3 (NLRP3) inflammasome in murine macrophages. In an LPS-induced ALI murine model, we found that sEH inhibitor 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl), TPPU, profoundly attenuated the pathological injury and inhibited the activation of the NLRP3 inflammasome, characterized by the reduction of the protein expression of NLRP3, ASC, pro-caspase-1, interleukin precursor (pro-IL-1ß), and IL-1ß p17 in the lungs of LPS-treated mice. In vitro, primary peritoneal macrophages from C57BL/6 were primed with LPS and activated with exogenous adenosine triphosphate (ATP). TPPU treatment remarkably reduced the expression of NLRP3 inflammasome-related molecules and blocked the activation of NLRP3 inflammasome. Importantly, four EETs (5,6-EET, 8,9-EET, 11,12-EET, and 14,15-EET) inhibited the activation of NLRP3 inflammasome induced by LPS + ATP or LPS + nigericin in macrophages in various degree. While the inhibitory effect of 5,6-EET was the weakest. Mechanismly, EETs profoundly decreased the content of reactive oxygen species (ROS) and restored the calcium overload in macrophages receiving LPS + ATP stimulation. In conclusion, this study suggests that EETs inhibit the activation of the NLRP3 inflammasome by suppressing calcium overload and ROS production in macrophages, contributing to the therapeutic potency to ALI.

PTUPB ameliorates high-fat diet-induced non-alcoholic fatty liver disease via inhibiting NLRP3 inflammasome activation in mice.

Non-alcoholic fatty liver disease (NAFLD) affects 25% of the global adult population, and no effective pharmacological treatment has been found. Products of arachidonic acid metabolism have been developed into a novel therapy for metabolic syndrome and diabetes. It has been demonstrated that protective actions of a novel dual cyclooxygenase-2 (COX-2) and soluble epoxide hydrolase (sEH) inhibitor, PTUPB, on the metabolic abnormalities. Here, we investigated the effects of PTUPB on hepatic steatosis in high-fat diet (HFD)-induced obese mice, as well as in hepatocytes in vitro. We found that PTUPB treatment reduced body weight, liver weight, liver triglyceride and cholesterol content, and the expression of lipolytic/lipogenic and lipid uptake related genes (Acc, Cd36, and Cidec) in HFD mice. In addition, PTUPB treatment arrested fibrotic progression with a decrease of collagen deposition and expression of Col1a1, Col1a3, and α-SMA. In vitro, PTUPB decreased palmitic acid-induced lipid deposition and downregulation of lipolytic/lipogenic genes (Acc and Cd36) in hepatocytes. Additionally, we found that PTUPB reduced the production of pro-inflammatory cytokines and suppressed the NLRP3 inflammasome activation in HFD mice and hepatocytes. In conclusion, dual inhibition of COX-2/sEH attenuates hepatic steatosis by inhibiting the NLRP3 inflammasome activation. PTUPB might be a promising potential therapy for liver steatosis associated with obesity.

Psoralen attenuates bleomycin-induced pulmonary fibrosis in mice through inhibiting myofibroblast activation and collagen deposition.

Idiopathic pulmonary fibrosis (IPF) is a progressive disease characterized by excessive deposition of extracellular matrix (ECM) and chronic inflammation with limited therapeutic options. Psoralen, a major active component extracted from Psoralea corylifolia L. seed, has several biological effects. However, the role of psoralen in IPF is still unclear. Here, we hypothesized that psoralen played an essential role in IPF in the inhibition of fibroblast proliferation and inflammatory response. A murine model of IPF was established by injecting bleomycin (BLM) intratracheally, and psoralen was administered for 14 days from the 7th to 21st day after BLM injection. Our results demonstrated that psoralen treatment reduced body weight loss and improved the survival rate of mice with IPF. Histological and immunofluorescent examination showed that psoralen alleviated BLM-induced lung parenchymal inflammatory and fibrotic alteration. Furthermore, psoralen inhibited proliferation and collagen synthesis of mouse fibroblasts and partially reversed BLM-induced expression of α-smooth muscle actin at both the tissue and cell level. Moreover, psoralen decreased the expression of transforming growth factor-ß1, interleukin-1ß, and tumor necrosis factor-α in the lungs of BLM-stimulated mice. Our results reveale for the first time that psoralen exerts therapeutic effects against IPF in a BLM-induced murine model.

Determinants of Clinical COPD Questionnaire in Patients with COPD: A Cross-Sectional Observational Study.

BACKGROUND: The Clinical COPD Questionnaire (CCQ) has been suggested by the Global Initiative of Chronic Obstructive Lung Disease (GOLD) as a comprehensive symptom measurement tool, which helps to classify patients in order to direct pharmacological treatment. Therefore, it is essential to understand its determinants. OBJECTIVES: To identify the determinants of the overall CCQ score and scores of its 3 subdomains among chronic obstructive pulmonary disease (COPD) patients from China. METHODS: A total of 1,241 COPD patients in the outpatient department of the Second Xiangya Hospital in China were recruited. Basic information and clinical data were collected. Differences in the GOLD categories based on Modified Medical Research Council Dyspnea Scale (mMRC), COPD Assessment Test (CAT), and CCQ were compared. Multiple linear regression analyses were performed to evaluate determinant factors of the total CCQ and subdomain scores. RESULTS: The total CCQ and/or separate domain scores significantly differed with sex, age, BMI, smoking status, biomass fuel exposure, exacerbation frequency, mMRC, CAT, and GOLD grades and groups. Subjects with asthma-COPD overlap (ACO) had worse health status based on CCQ than those with COPD alone. As for the 16 subgroups based on GOLD 2017, statistical differences in the total CCQ and functional domain scores were found among subgroups 1A-4A, 1B-4B, and 1D-4D. The mMRC classified much more patients into more symptom groups than CAT and CCQ. No significant difference was observed in the GOLD categories between the CAT and CCQ (cut point = 1.5). Multiple linear regression analysis showed that smoking status, underweight, ACO, post-bronchodilator FEV1% predicted <50%, exacerbation history, and mMRC were independently associated with the total CCQ score. Only 3 variables were significantly associated with the symptom domain: ACO, exacerbations, and mMRC; for the functional domain, age ≥75 years, ACO, post-bronchodilator FEV1% predicted <50%, exacerbation history, and mMRC were significant; female sex, underweight, frequent exacerbations (≥2), and mMRC were significantly associated with higher scores in the mental domain. CONCLUSIONS: The classification of COPD produced by mMRC, CAT, and CCQ was not identical. Smoking status, underweight, ACO, post-bronchodilator FEV1% predicted <50%, exacerbation history, and mMRC were associated with lower health-related quality of life assessed by the total CCQ score, while different subdomains of CCQ had different determinant factors.

Prevalence and Characteristics of Pain in Patients of Chronic Obstructive Pulmonary Disease: A Cross-Sectional Study in China.

The purposes of this study were to: (1) study the prevalence of pain in patients with mild-to-very severe chronic obstructive pulmonary disease (COPD) in China; (2) compare the differences in pain characteristics between stable COPD and acute exacerbation of COPD (AECOPD); (3) explore the clinical associations with pain in those with COPD. This cross-sectional study was conducted in China from October 24, 2017, to January 11, 2019. A face-to-face interview was conducted to collect data. The Chinese version of the brief pain inventory (BPI-C) was applied to investigate the pain characteristics in patients with COPD. Of the 901 patients in this study, 226 (25.1%) patients reported pain problems. The prevalence of pain in patients with mild to very severe COPD was 32.9%, 23.9%, 25.2%, and 23.5%, respectively (p = 0.447). According to the BPI-C results, 31.3% (31/99) of patients reported pain of AECOPD, compared to 24.3% (195/802) of stable COPD (p = 0.13). Reported pain intensity and pain interference evaluated by the BPI-C were significantly higher in AECOPD than stable COPD (p < 0.001, p < 0.05, respectively). Those with body mass index (BMI) ≥ 24kg/m2 or COPD assessment test (CAT) score > 20 were significantly more likely to have pain problems than BMI < 24kg/m2 (aOR = 1.568, a95IC = 1.132-2.170, p = 0.007) or CAT ≤ 20 (aOR= 1.754, a95IC = 1.213-2.536, p = 0.003). Pain was common in patients with both stable COPD and AECOPD. AECOPD patients had a significantly higher pain intensity than stable COPD. Overweight and CAT > 20 were significantly related to higher prevalence of pain.

Inhibition of glycolysis alleviates lipopolysaccharide-induced acute lung injury in a mouse model.

Gluconic metabolic reprogramming, immune response, and inflammation are intimately linked. Glycolysis involves in the pathologic progress in acute and chronic inflammatory diseases. However, the involvement of glycolysis in the acute lung injury (ALI) is still unclear. This study investigated the role of glycolysis in an animal model of ALI. First, we found that lactate content in serum was remarkably increased in ALI patients and a murine model induced by intratracheal administration of lipopolysaccharide (LPS). The key proteins involving in glycolysis were robustly elevated, including HK2, PKM2, and HIF-1α. Intriguingly, inhibition of glycolysis by 2-deoxyglucose (2-DG) pronouncedly attenuated the lung tissue pathological injury, accumulation of neutrophil, oxidative stress, expression of proinflammatory factors in the lung of ALI mice induced by LPS. The 2-DG treatment also strongly suppressed the activation of the NOD-like receptor (NLR) family and pyrin domain-containing protein 3 (NLRP3) inflammasome. Furthermore, we investigated the role of glycolysis in the inflammatory response of primary murine macrophages activated by LPS in vitro. We found that the 2-DG treatment remarkably reduced the expression of proinflammatory factors induced by LPS, including tumor necrosis factor-α messenger RNA (mRNA), pro-interleukin (IL)-1ß mRNA, pro-IL-18 mRNA, NLRP3 mRNA, caspase-1 mRNA, and IL-1ß protein. Altogether, these data provide a novel link between gluconic metabolism reprogramming and uncontrolled inflammatory response in ALI. This study suggests glycolytic inhibition as an effective anti-inflammatory strategy in treating ALI.

Prevalence and characteristics of COPD among pneumoconiosis patients at an occupational disease prevention institute: a cross-sectional study.

BACKGROUND: Pneumoconiosis may play an important role in the development of chronic obstructive pulmonary disease (COPD), and the complication of COPD may impose a heavy burden of illness. METHODS: The study was conducted in Hunan Province in China from December 1, 2015, to December 1, 2016. Consecutive underground male pneumoconiosis patients employed for at least 1 year were recruited from the Hunan Occupational Disease Prevention Institute. Patient information, respiratory symptoms and clinical data were collected using a structured questionnaire. The diagnosis of COPD were assessed using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. Logistic regression analyses were conducted to examine the clinical and demographic risk factors of COPD among pneumoconiosis patients. RESULTS: The prevalence of COPD in our sample of pneumoconiosis patients was 18.65% (119/638). In pneumoconiosis patients with and without smoking history, the prevalence of COPD was 19.32 and 16.77%. Compared with non-COPD patients, those with COPD are older in age, have longer exposure time, have lower body mass index (BMI), have a higher smoking index and have worse pulmonary function (all p < 0.05). For the five respiratory symptoms (cough, sputum, wheeze, dyspnea, and chest tightness), only the presence of wheeze and the severity scores for wheeze or dyspnea showed significant differences between the COPD and non-COPD groups (p < 0.01). Multivariate logistic regression analysis revealed that advanced pneumoconiosis category, older age and the presence of wheeze symptoms were significant risk factors for the development of COPD among pneumoconiosis patients. CONCLUSION: Pneumoconiosis patients are at a high risk of COPD, and pneumoconiosis patients with COPD may suffer more severe respiratory symptoms, such as wheeze and dyspnea, than patients without COPD. Advanced pneumoconiosis category, older age and the presence of wheeze symptoms are associated with an increased risk of COPD in pneumoconiosis. We proposed that a routine assessment of lung function is necessary for timely and adequate clinical management.

Soluble epoxide hydrolase inhibitor 1-trifluoromethoxyphenyl-3- (1-propionylpiperidin-4-yl) urea attenuates bleomycin-induced pulmonary fibrosis in mice.

Epoxyeicosatrienoic acids (EETs), the metabolites of arachidonic acid derived from the cytochrome P450 (CYP450) epoxygenases, are mainly metabolized by soluble epoxide hydrolase (sEH) to their corresponding diols. EETs but not their diols, have anti-inflammatory properties and inhibition of sEH might provide protective effects against inflammatory fibrosis. We test the effects of a selected sEH inhibitor, 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU), on bleomycin-induced pulmonary fibrosis (PF) in mice. A mouse model of PF was established by intratracheal injection of bleomycin and TPPU was administered for 21 days after bleomycin injection. We found TPPU treatment improved the body weight loss and survival rate of bleomycin-stimulated mice. Histological examination showed that TPPU treatment alleviated bleomycin-induced inflammation and maintained the alveolar structure of the pulmonary tissues. TPPU also decreased the bleomycin-induced deposition of collagen and the expression of procollagen I mRNA in lung tissues of mice. TPPU decreased the transforming growth factor-ß1 (TGF-ß1), interleukin-1ß (IL-1ß) and IL-6 levels in the serum of bleomycin-stimulated mice. Furthermore, TPPU inhibited the proliferation and collagen synthesis of mouse fibroblasts and partially reversed TGF-ß1-induced α-smooth muscle actin expression. Our results indicate that the inhibition of sEH attenuates bleomycin-induced inflammation and collagen deposition and therefore prevents bleomycin-induced PF in a mouse model.

LRG1 promotes the apoptosis of pulmonary microvascular endothelial cells through KLK10 in chronic obstructive pulmonary disease.

INTRODUCTION: Cigarette smoking is one of the most important causes of COPD and could induce the apoptosis of pulmonary microvascular endothelial cells (PMVECs). The conditional knockout of LRG1 from endothelial cells reduced emphysema in mice. However, the mechanism of the deletion of LRG1 from endothelial cells rescued by cigarette smoke (CS) induced emphysema remains unclear. This research aimed to demonstrate whether LRG1 promotes the apoptosis of PMVECs through KLK10 in COPD. METHODS: Nineteen patients were divided into three groups: control non-COPD (n=7), smoker non-COPD (n=7), and COPD (n=5). The emphysema mouse model defined as the CS exposure group was induced by CS exposure plus cigarette smoke extract (CSE) intraperitoneal injection for 28 days. Primary PMVECs were isolated from the mouse by magnetic bead sorting method via CD31-Dynabeads. Apoptosis was detected by western blot and flow cytometry. RESULTS: LRG1 was increased in lung tissue of COPD patients and CS exposure mice, and CSE-induced PMVECs apoptosis model. KLK10 was over-expressed in lung tissue of COPD patients and CS exposure mice, and CSE-induced PMVECs apoptosis model. LRG1 promoted apoptosis in PMVECs. LRG1 knockdown reversed CSE-induced apoptosis in PMVECs. The mRNA and protein expression of KLK10 were increased after over-expressed LRG1 in PMVECs isolated from mice. Similarly, both the mRNA and protein levels of KLK10 were decreased after LRG1 knockdown in PMVECs. The result of co-immunoprecipitation revealed a protein-protein interaction between LRG1 and KLK10 in PMVECs. KLK10 promoted apoptosis via the down-regulation of Bcl-2/Bax in PMVECs. KLK10 knockdown could reverse CSE-induced apoptosis in PMVECs. CONCLUSIONS: LRG1 promotes apoptosis via up-regulation of KLK10 in PMVECs isolated from mice. KLK10 promotes apoptosis via the down-regulation of Bcl-2/Bax in PMVECs. There was a direct protein-protein interaction between LRG1 and KLK10 in PMVECs. Our novel findings provide insights into the understanding of LRG1/KLK10 function as a potential molecule in COPD.

Neutrophil extracellular traps trigger alveolar epithelial cell necroptosis through the cGAS-STING pathway during acute lung injury in mice.

Extensive loss of alveolar epithelial cells (AECs) undergoing necroptosis is a crucial mechanism of acute lung injury (ALI), but its triggering mechanism needs to be thoroughly investigated. Neutrophil extracellular traps (NETs) play a significant role in ALI. However, the effect of NETs on AECs' death has not been clarified. Our study found that intratracheal instillation of NETs disrupted lung tissue structure, suggesting that NETs could induce ALI in mice. Moreover, we observed that NETs could trigger necroptosis of AECs in vivo and in vitro. The phosphorylation levels of RIPK3 and MLKL were increased in MLE12 cells after NETs treatment (P < 0.05). Mechanistically, NETs taken up by AECs through endocytosis activated the cGAS-STING pathway and triggered AECs necroptosis. The expression of cGAS, STING, TBK1 and IRF3 were increased in MLE12 cells treated with NETs (P < 0.05). Furthermore, the cGAS inhibitor RU.521 inhibited NETs-triggered AECs necroptosis and alleviated the pulmonary damage induced by NETs in mice. In conclusion, our study demonstrates that NETs taken up by AECs via endocytosis can activate the cGAS-STING pathway and trigger AECs necroptosis to promote ALI in mice. Our findings indicate that targeting the NETs/cGAS-STING/necroptosis pathway in AECs is an effective strategy for treating ALI.

Krüppel-like transcription factor 14 alleviates alveolar epithelial cell senescence by inhibiting endoplasmic reticulum stress in pulmonaryfibrosis.

Pulmonary fibrosis (PF) is defined as a specific form of chronic, progressive fibrosing interstitial pneumonia, occurring primarily in older adults with poor prognosis. Alveolar epithelial cell (AEC) senescence is the critical pathological mechanism of PF. However, the molecular mechanisms regulating AEC senescence in PF are incompletely understood. Herein, we provided evidence to support the function of Krüppel-like factor 14 (KLF14), a novel Krüppel-like transcription factor, in the regulation of AEC senescence during PF. We confirmed that the expression of KLF14 was up-regulated in PF patients and mice treated with bleomycin (BLM). KLF14 knockdown resulted in more pronounced structural disruption of the lung tissue and swelling of the alveolar septum, which led to significantly increased mortality in BLM-induced PF mice. Mechanistically, RNA-seq analysis indicated that KLF14 decreased the senescence of AECs by inhibiting endoplasmic reticulum (ER) stress. Furthermore, the pharmacological activation of KLF14 conferred protection against PF in mice. In conclusion, our findings reveal a protective role for KLF14 in preventing AECs from senescence and shed light on the development of KLF14-targeted therapeutics for PF.