TRIM27-Induced Protective Autophagy: A Novel Therapeutic Approach for Pneumonia.

BACKGROUND: Pneumonia is a prevalent respiratory ailment involving complex physiological and pathological mechanisms. The tripartite motif containing 27 (TRIM27) plays a crucial role in regulating inflammation mechanisms. Therefore, the purpose of this study is to further explore the therapeutic potential of TRIM27 in pneumonia, based on its regulatory mechanisms in inflammation and autophagy. METHODS: This study established a mouse pneumonia animal model through lipopolysaccharide (LPS) administration, designating it as the LPS model group. Subsequently, adenovirus-mediated TRIM27 overexpression was implemented in the animals of the LPS model group, creating the TRIM27 treatment group. After a 7-day treatment period, lung tissues from the mice were collected. Various techniques, including immunohistochemistry, quantitative reverse transcription PCR (RT-qPCR), western blot, enzyme-linked immunosorbent assay (ELISA), and electron microscopy were utilized to analyze the impact of TRIM27 overexpression on inflammatory factors, oxidative stress, autophagy, and inflammatory processes in pulmonary tissues. Finally, an in vitro LPS cell model was established, and the effects of TRIM27 overexpression and autophagy inhibition on inflammatory cytokines and autophagosomes in LPS-induced inflammatory cells were examined through RT-qPCR and immunofluorescence techniques. RESULTS: The research findings demonstrate a significant reduction in the elevated levels of interleukin-6 (IL-6), IL-1ß, and Tumor necrosis factor-alpha (TNF-α) induced by LPS with TRIM27 overexpression (p < 0.01). Conversely, the autophagy inhibitor 3-Methyladenine (3-MA) diminished the effects induced by TRIM27 overexpression. Moreover, TRIM27 overexpression enhanced the expression of Microtubule-associated protein 1A/1B light chain 3 (LC3) II/I and Beclin-1 proteins in mice subjected to LPS stimulation (p < 0.01), while reducing the expression of the p62 protein (p < 0.01). The addition of 3-MA, however, decreased Beclin-1 expression and inhibited autophagy (p < 0.01). Additionally, TRIM27 overexpression decreased the expression of NOD-like receptor thermal protein domain associated protein 3 (NLRP3), cleaved caspase-1, IL-1ß, and Gasdermin D N-terminal fragment (GSDMD-N) proteins in LPS-stimulated mice (p < 0.05). TRIM27 overexpression also decreased the levels of malondialdehyde (MDA), Activating Transcription Factor 6 (ATF6), and C/EBP-homologous protein (CHOP), while increasing the levels of superoxide dismutase (SOD) and glutathione (GSH) in mice exposed to LPS (p < 0.01). CONCLUSION: The induction of TRIM27 overexpression emerges as a potential and effective pneumonia treatment. The underlying mechanism may involve inducing protective autophagy, thereby reducing oxidative stress and cell pyroptosis.

Twenty-Four week Taichi training improves pulmonary diffusion capacity and glycemic control in patients with Type 2 diabetes mellitus.

This study evaluated the effect of 24-week Taichi training and Taichi plus resistance band training on pulmonary diffusion capacity and glycemic control in patients with Type 2 diabetes mellitus (T2DM). Forty-eight patients with T2DM were randomly divided into three groups: Group A-Taichi training: practiced Taichi 60 min/day, 6 days/week for 24 weeks; Group B-Taichi plus resistance band training: practiced 60-min Taichi 4 days/week plus 60-min resistance band training 2 days/week for 24 weeks; and Group C-controls: maintaining their daily lifestyles. Stepwise multiple regression analysis was applied to predict diffusion capacity of the lungs for carbon monoxide (DLCO) by fasting blood glucose, insulin, glycosylated hemoglobin (HbA1c), tumour necrosis factor alpha (TNF-α), von Willebrand Factor (vWF), interleukin-6 (IL-6), intercellular adhesion molecule 1 (ICAM-1), endothelial nitric oxide synthase (eNOS), nitric oxide (NO), endothelin-1 (ET-1), vascular endothelial growth factor, and prostaglandin I-2. Taichi with or without resistance band training significantly improved DLCO, increased insulin sensitivity, eNOS and NO, and reduced fasting blood glucose, insulin, HbA1c, TNF-α, vWF, IL-6, ICAM-1, and ET-1. There was no change in any of these variables in the control group. DLCO was significantly predicted (R2 = 0.82) by insulin sensitivity (standard-ß = 0.415, P<0.001), eNOS (standard-ß = 0.128, P = 0.017), TNF-α (standard-ß = -0.259, P = 0.001), vWF (standard-ß = -0.201, P = 0.007), and IL-6 (standard-ß = -0.175, P = 0.032) in patients with T2DM. The impact of insulin sensitivity was the most important predictor for the variation of DLCO based on the multiple regression modeling. This study demonstrates that 24-week Taichi training and Taichi plus resistance band training effectively improve pulmonary diffusion capacity and blood glycemic control in patients with T2DM. Variation of DLCO is explained by improved insulin sensitivity and endothelial function, and reduced inflammatory markers, including TNF-α, vWF, and IL-6.

Garlic oil supplementation blocks inflammatory pyroptosis-related acute lung injury by suppressing the NF-κB/NLRP3 signaling pathway via H2S generation.

Acute lung injury (ALI) is a major cause of acute respiratory failure with a high morbidity and mortality rate, and effective therapeutic strategies for ALI remain limited. Inflammatory response is considered crucial for the pathogenesis of ALI. Garlic, a globally used cooking spice, reportedly exhibits excellent anti-inflammatory bioactivity. However, protective effects of garlic against ALI have never been reported. This study aimed to investigate the protective effects of garlic oil (GO) supplementation on lipopolysaccharide (LPS)-induced ALI models. Hematoxylin and eosin staining, pathology scores, lung myeloperoxidase (MPO) activity measurement, lung wet/dry (W/D) ratio detection, and bronchoalveolar lavage fluid (BALF) analysis were performed to investigate ALI histopathology. Real-time polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay were conducted to evaluate the expression levels of inflammatory factors, nuclear factor-κB (NF-κB), NLRP3, pyroptosis-related proteins, and H2S-producing enzymes. GO attenuated LPS-induced pulmonary pathological changes, lung W/D ratio, MPO activity, and inflammatory cytokines in the lungs and BALF. Additionally, GO suppressed LPS-induced NF-κB activation, NLRP3 inflammasome expression, and inflammatory-related pyroptosis. Mechanistically, GO promoted increased H2S production in lung tissues by enhancing the conversion of GO-rich polysulfide compounds or by increasing the expression of H2S-producing enzymes in vivo. Inhibition of endogenous or exogenous H2S production reversed the protective effects of GO on ALI and eliminated the inhibitory effects of GO on NF-κB, NLRP3, and pyroptotic signaling pathways. Overall, these findings indicate that GO has a critical anti-inflammatory effect and protects against LPS-induced ALI by suppressing the NF-κB/NLRP3 signaling pathway via H2S generation.

Endothelial cell expression of a STING gain-of-function mutation initiates pulmonary lymphocytic infiltration.

Patients afflicted with Stimulator of interferon gene (STING) gain-of-function mutations frequently present with debilitating interstitial lung disease (ILD) that is recapitulated in mice expressing the STINGV154M mutation (VM). Prior radiation chimera studies revealed an unexpected and critical role for non-hematopoietic cells in initiating ILD. To identify STING-expressing non-hematopoietic cell types required for the development of ILD, we use a conditional knockin (CKI) model and direct expression of the VM allele to hematopoietic cells, fibroblasts, epithelial cells, or endothelial cells. Only endothelial cell-targeted VM expression results in enhanced recruitment of immune cells to the lung associated with elevated chemokine expression and the formation of bronchus-associated lymphoid tissue, as seen in the parental VM strain. These findings reveal the importance of endothelial cells as instigators of STING-driven lung disease and suggest that therapeutic targeting of STING inhibitors to endothelial cells could potentially mitigate inflammation in the lungs of STING-associated vasculopathy with onset in infancy (SAVI) patients or patients afflicted with other ILD-related disorders.

The endothelium: gatekeeper to lung ischemia-reperfusion injury.

The success of lung transplantation is limited by the high rate of primary graft dysfunction due to ischemia-reperfusion injury (IRI). Lung IRI is characterized by a robust inflammatory response, lung dysfunction, endothelial barrier disruption, oxidative stress, vascular permeability, edema, and neutrophil infiltration. These events are dependent on the health of the endothelium, which is a primary target of IRI that results in pulmonary endothelial barrier dysfunction. Over the past 10 years, research has focused more on the endothelium, which is beginning to unravel the multi-factorial pathogenesis and immunologic mechanisms underlying IRI. Many important proteins, receptors, and signaling pathways that are involved in the pathogenesis of endothelial dysfunction after IR are starting to be identified and targeted as prospective therapies for lung IRI. In this review, we highlight the more significant mediators of IRI-induced endothelial dysfunction discovered over the past decade including the extracellular glycocalyx, endothelial ion channels, purinergic receptors, kinases, and integrins. While there are no definitive clinical therapies currently available to prevent lung IRI, we will discuss potential clinical strategies for targeting the endothelium for the treatment or prevention of IRI. The accruing evidence on the essential role the endothelium plays in lung IRI suggests that promising endothelial-directed treatments may be approaching the clinic soon. The application of therapies targeting the pulmonary endothelium may help to halt this rapid and potentially fatal injury.

Neopterin in patients with COPD, asthma, and ACO: association with endothelial and lung functions.

BACKGROUND AND OBJECTIVE: Endothelial dysfunction has been widely recognized in chronic airway diseases, including chronic obstructive pulmonary disease (COPD) and asthma; however, it remains unclear in asthma-COPD overlap (ACO). Neopterin (NP), a metabolite of guanosine triphosphate, is a novel biomarker for identifying the increased risk of adverse cardiovascular events. This study aims to investigate the association of NP with endothelial dysfunction and impaired lung function in COPD, asthma, and ACO patients. METHODS: A total of 77 subjects were prospectively recruited. All the participants underwent lung function test, endothelial function evaluation, including pulse wave velocity (PWV) and flow-mediated dilation (FMD), and blood sample detection. Moreover, the effect of NP on endothelial cells (ECs) in anoxic environments was assessed in vitro. RESULTS: Endothelial function was significantly decreased in the COPD and ACO patients compared with that in the healthy controls (P < 0.05). Forced expiratory volume in 1 s (FEV1) was negatively correlated with PWV and positively correlated with FMD (P < 0.05). NP was significantly increased in patients with chronic respiratory diseases compared with that in the control group, with COPD being the highest, followed by asthma, and ACO as the last (P < 0.05). The plasma level of NP exhibited negative correlations with FEV1 and positive correlations with PWV (P < 0.05). In vitro, a high level of NP increased the reactive oxygen species (ROS) and decreased the mitochondrial membrane potential (ΔΨm) of ECs dose-dependently in a hypoxic environment (P < 0.05). CONCLUSION: NP was related to disease severity of chronic airway diseases and involved in the pathogenesis of endothelial dysfunction. A high NP level may contribute to endothelial dysfunction by increasing the oxidative stress of ECs dose-dependently in a hypoxic environment. Our findings may provide a novel evaluation and therapeutic target for endothelial dysfunction related to chronic airway diseases.

PI3Kγδ inhibition suppresses key disease features in a rat model of asthma.

BACKGROUND: Two isoforms of Phosphoinositide 3-kinase (PI3K), p110γ and p110δ, are predominantly expressed in leukocytes and represent attractive therapeutic targets for the treatment of allergic asthma. The study aim was to assess the impact of administration of an inhaled PI3Kγδ inhibitor (AZD8154) in a rat model of asthma. METHODS: Firstly, we checked that the tool compound, AZD8154, inhibited rat PI3K γ & δ kinases using rat cell-based assays. Subsequently, a time-course study was conducted in a rat model of asthma to assess PI3K activity in the lung and how it is temporally associated with other key transcription pathways and asthma like features of the model. Finally, the impact on lung dosed AZD8154 on target engagement, pathway specificity, airway inflammation and lung function changes was assessed. RESULTS: Data showed that AZD8154 could inhibit rat PI3K γ & δ isoforms and, in a rat model of allergic asthma the PI3K pathway was activated in the lung. Intratracheal administration of AZD8154 caused a dose related suppression PI3K pathway activation (reduction in pAkt) and unlike after budesonide treatment, STAT and NF-κB pathways were not affected by AZD8154. The suppression of the PI3K pathway led to a marked inhibition of airway inflammation and reduction in changes in lung function. CONCLUSION: These data show that a dual PI3Kγδ inhibitor suppress key features of disease in a rat model of asthma to a similar degree as budesonide and indicate that dual PI3Kγδ inhibition may be an effective treatment for people suffering from allergic asthma.

Effects of environmental exposure to iron powder on healthy and elastase-exposed mice.

Prolonged exposure to iron powder and other mineral dusts can threaten the health of individuals, especially those with COPD. The goal of this study was to determine how environmental exposure to metal dust from two different mining centers in Brazil affects lung mechanics, inflammation, remodeling and oxidative stress responses in healthy and elastase-exposed mice. This study divided 72 male C57Bl/6 mice into two groups, the summer group and the winter group. These groups were further divided into six groups: control, nonexposed (SAL); nonexposed, given elastase (ELA); exposed to metal powder at a mining company (SAL-L1 and ELA-L1); and exposed to a location three miles away from the mining company (SAL-L2 and ELA-L2) for four weeks. On the 29th day of the protocol, the researchers assessed lung mechanics, bronchoalveolar lavage fluid (BALF), inflammation, remodeling, oxidative stress, macrophage iron and alveolar wall alterations (mean linear intercept-Lm). The Lm was increased in the ELA, ELA-L1 and ELA-L2 groups compared to the SAL group (p < 0.05). There was an increase in the total number of cells and macrophages in the ELA-L1 and ELA-L2 groups compared to the other groups (p < 0.05). Compared to the ELA and SAL groups, the exposed groups (ELA-L1, ELA-L2, SAL-L1, and SAL-L2) exhibited increased expression of IL-1ß, IL-6, IL-10, IL-17, TNF-α, neutrophil elastase, TIMP-1, MMP-9, MMP-12, TGF-ß, collagen fibers, MUC5AC, iNOS, Gp91phox, NFkB and iron positive macrophages (p < 0.05). Although we did not find differences in lung mechanics across all groups, there were low to moderate correlations between inflammation remodeling, oxidative stress and NFkB with elastance, resistance of lung tissue and iron positive macrophages (p < 0.05). Environmental exposure to iron, confirmed by evaluation of iron in alveolar macrophages and in air, exacerbated inflammation, initiated remodeling, and induced oxidative stress responses in exposed mice with and without emphysema. Activation of the iNOS, Gp91phox and NFkB pathways play a role in these changes.

Lipid nanoparticle encapsulated large peritoneal macrophages migrate to the lungs via the systemic circulation in a model of clodronate-mediated lung-resident macrophage depletion.

Rationale: A mature tissue resident macrophage (TRM) population residing in the peritoneal cavity has been known for its unique ability to migrate to peritoneally located injured tissues and impart wound healing properties. Here, we sought to expand on this unique ability of large peritoneal macrophages (LPMs) by investigating whether these GATA6+ LPMs could also intravasate into systemic circulation and migrate to extra-peritoneally located lungs upon ablating lung-resident alveolar macrophages (AMs) by intranasally administered clodronate liposomes in mice. Methods: C12-200 cationic lipidoid-based nanoparticles were employed to selectively deliver a small interfering RNA (siRNA)-targeting CD-45 labeled with a cyanine 5.5 (Cy5.5) dye to LPMs in vivo via intraperitoneal injection. We utilized a non-invasive optical technique called Diffuse In Vivo Flow Cytometry (DiFC) to then systemically track these LPMs in real time and paired it with more conventional techniques like flow cytometry and immunocytochemistry to initially confirm uptake of C12-200 encapsulated siRNA-Cy5.5 (siRNA-Cy5.5 (C12-200)) into LPMs, and further track them from the peritoneal cavity to the lungs in a mouse model of AM depletion incited by intranasally administered clodronate liposomes. Also, we stained for LPM-specific marker zinc-finger transcription factor GATA6 in harvested cells from biofluids like broncho-alveolar lavage as well as whole blood to probe for Cy5.5-labeled LPMs in the lungs as well as in systemic circulation. Results: siRNA-Cy5.5 (C12-200) was robustly taken up by LPMs. Upon depletion of lung-resident AMs, these siRNA-Cy5.5 (C12-200) labeled LPMs rapidly migrated to the lungs via systemic circulation within 12-24 h. DiFC results showed that these LPMs intravasated from the peritoneal cavity and utilized a systemic route of migration. Moreover, immunocytochemical staining of zinc-finger transcription factor GATA6 further confirmed results from DiFC and flow cytometry, confirming the presence of siRNA-Cy5.5 (C12-200)-labeled LPMs in the peritoneum, whole blood and BALF only upon clodronate-administration. Conclusion: Our results indicate for the very first time that selective tropism, migration, and infiltration of LPMs into extra-peritoneally located lungs was dependent on clodronate-mediated AM depletion. These results further open the possibility of therapeutically utilizing LPMs as delivery vehicles to carry nanoparticle-encapsulated oligonucleotide modalities to potentially address inflammatory diseases, infectious diseases and even cancer.

Lung-specific interleukin 6 mediated transglutaminase 2 activation and cardiopulmonary fibrogenesis.

Pulmonary hypertension (PH) pathogenesis is driven by inflammatory and metabolic derangements as well as glycolytic reprogramming. Induction of both interleukin 6 (IL6) and transglutaminase 2 (TG2) expression participates in human and experimental cardiovascular diseases. However, little is known about the role of TG2 in these pathologic processes. The current study aimed to investigate the molecular interactions between TG2 and IL6 in mediation of tissue remodeling in PH. A lung-specific IL6 over-expressing transgenic mouse strain showed elevated right ventricular (RV) systolic pressure as well as increased wet and dry tissue weights and tissue fibrosis in both lungs and RVs compared to age-matched wild-type littermates. In addition, IL6 over-expression induced the glycolytic and fibrogenic markers, hypoxia-inducible factor 1α, pyruvate kinase M2 (PKM2), and TG2. Consistent with these findings, IL6 induced the expression of both glycolytic and pro-fibrogenic markers in cultured lung fibroblasts. IL6 also induced TG2 activation and the accumulation of TG2 in the extracellular matrix. Pharmacologic inhibition of the glycolytic enzyme, PKM2 significantly attenuated IL6-induced TG2 activity and fibrogenesis. Thus, we conclude that IL6-induced TG2 activity and cardiopulmonary remodeling associated with tissue fibrosis are under regulatory control of the glycolytic enzyme, PKM2.

Inhibition of GBP5 activates autophagy to alleviate inflammatory response in LPS-induced lung injury in mice.

BACKGROUND: Pulmonary emphysema is a condition that causes damage to the lung tissue over time. GBP5, as part of the guanylate-binding protein family, is dysregulated in mouse pulmonary emphysema. However, the role of GBP5 in lung inflammation in ARDS remains unveiled. METHODS: To investigate whether GBP5 regulates lung inflammation and autophagy regulation, the study employed a mouse ARDS model and MLE-12 cell culture. Vector transfection was performed for the genetic manipulation of GBP5. Then, RT-qPCR, WB and IHC staining were conducted to assess its transcriptional and expression levels. Histological features of the lung tissue were observed through HE staining. Moreover, ELISA was conducted to evaluate the secretion of inflammatory cytokines, autophagy was assessed by immunofluorescent staining, and MPO activity was determined using a commercial kit. RESULTS: Our study revealed that GBP5 expression was altered in mouse ARDS and LPS-induced MLE-12 cell models. Moreover, the suppression of GBP5 reduced lung inflammation induced by LPS in mice. Conversely, overexpression of GBP5 diminished the inhibitory impact of LPS on ARDS during autophagy, leading to increased inflammation. In the cell line of MLE-12, GBP5 exacerbates LPS-induced inflammation by blocking autophagy. CONCLUSION: The study suggests that GBP5 facilitates lung inflammation and autophagy regulation. Thus, GBP5 could be a potential therapeutic approach for improving ARDS treatment outcomes, but further research is required to validate these findings.

Pharmacological expansion of type 2 alveolar epithelial cells promotes regenerative lower airway repair.

Type 2 alveolar epithelial cells (AEC2s) are stem cells in the adult lung that contribute to lower airway repair. Agents that promote the selective expansion of these cells might stimulate regeneration of the compromised alveolar epithelium, an etiology-defining event in several pulmonary diseases. From a high-content imaging screen of the drug repurposing library ReFRAME, we identified that dipeptidyl peptidase 4 (DPP4) inhibitors, widely used type 2 diabetes medications, selectively expand AEC2s and are broadly efficacious in several mouse models of lung damage. Mechanism of action studies revealed that the protease DPP4, in addition to processing incretin hormones, degrades IGF-1 and IL-6, essential regulators of AEC2 expansion whose levels are increased in the luminal compartment of the lung in response to drug treatment. To selectively target DPP4 in the lung with sufficient drug exposure, we developed NZ-97, a locally delivered, lung persistent DPP4 inhibitor that broadly promotes efficacy in mouse lung damage models with minimal peripheral exposure and good tolerability. This work reveals DPP4 as a central regulator of AEC2 expansion and affords a promising therapeutic approach to broadly stimulate regenerative repair in pulmonary disease.

Prognostic Model for High-Grade Neuroendocrine Carcinoma of the Lung Incorporating Genomic Profiling and Poly (ADP-ribose) Polymerase-1 Expression.

PURPOSE: High-grade neuroendocrine carcinoma (HGNEC) of the lung is an aggressive cancer with a complex biology. We aimed to explore the prognostic value of genetic aberrations and poly(ADP-ribose) polymerase-1 (PARP1) expression in HGNEC and to establish a novel prognostic model. MATERIALS AND METHODS: We retrospectively enrolled 191 patients with histologically confirmed HGNEC of the lung. Tumor tissues were analyzed using PARP1 immunohistochemistry (IHC; N = 191) and comprehensive cancer panel sequencing (n = 102). Clinical and genetic data were used to develop an integrated Cox hazards model. RESULTS: Strong PARP1 IHC expression (intensity 3) was observed in 153 of 191 (80.1%) patients, and the mean PARP1 H-score was 285 (range, 5-300). To develop an integrated Cox hazard model, our data set included information from 357 gene mutations and 19 clinical profiles. When the targeted mutation profiles were combined with clinical profiles, 12 genes (ATRX, CCND2, EXT2, FGFR2, FOXO1, IL21R, MAF, TGM7, TNFAIP3, TP53, TSHR, and DDR2) were identified as prognostic factors for survival. The integrated Cox hazard model, which combines mutation profiles with a baseline model, outperformed the baseline model (incremental area under the curve 0.84 v 0.78; P = 8.79e-12). The integrated model stratified patients into high- and low-risk groups with significantly different disease-free and overall survival (integrated model: hazard ratio, 7.14 [95% CI, 4.07 to 12.54]; P < .01; baseline model: 4.38 [2.56 to 7.51]; P < .01). CONCLUSION: We introduced a new prognostic model for HGNEC that combines genetic and clinical data. The integrated Cox hazard model outperformed the baseline model in predicting the survival of patients with HGNEC.

Erythropoietin alleviates lung ischemia-reperfusion injury by activating the FGF23/FGFR4/ERK signaling pathway.

Background: The purpose of the present study was to investigate the effect of erythropoietin (EPO) on lung ischemia-reperfusion injury (LIRI). Methods: Sprague Dawley rats and BEAS-2B cells were employed to construct an ischemia-reperfusion (I/R)-induced model in vivo and in vitro, respectively. Afterward, I/R rats and tert-butyl hydroperoxide (TBHP)-induced cells were treated with different concentrations of EPO. Furthermore, 40 patients with LIRI and healthy controls were enrolled in the study. Results: It was observed that lung tissue damage, cell apoptosis and the expression of BAX and caspase-3 were higher in the LIRI model in vivo and in vitro than in the control group, nevertheless, the Bcl-2, FGF23 and FGFR4 expression level was lower than in the control group. EPO administration significantly reduced lung tissue damage and cell apoptosis while also up-regulating the expression of FGF23 and FGFR4. Rescue experiments indicated that EPO exerted a protective role associated with the FGF23/FGFR4/p-ERK1/2 signal pathway. Notably, the expression of serum EPO, FGF23, FGFR4 and Bcl-2 was decreased in patients with LIRI, while the expression of caspase-3 and BAX was higher. Conclusion: EPO could effectively improve LIRI, which might be related to the activation of the FGF23/FGFR4/p-ERK1/2 signaling pathway.

NR2F2 alleviates pulmonary fibrosis by inhibition of epithelial cell senescence.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fatal, and aging-associated interstitial lung disease with a poor prognosis and limited treatment options, while the pathogenesis remains elusive. In this study, we found that the expression of nuclear receptor subfamily 2 group F member 2 (NR2F2), a member of the steroid thyroid hormone superfamily of nuclear receptors, was reduced in both IPF and bleomycin-induced fibrotic lungs, markedly in bleomycin-induced senescent epithelial cells. Inhibition of NR2F2 expression increased the expression of senescence markers such as p21 and p16 in lung epithelial cells, and activated fibroblasts through epithelial-mesenchymal crosstalk, inversely overexpression of NR2F2 alleviated bleomycin-induced epithelial cell senescence and inhibited fibroblast activation. Subsequent mechanistic studies revealed that overexpression of NR2F2 alleviated DNA damage in lung epithelial cells and inhibited cell senescence. Adenovirus-mediated Nr2f2 overexpression attenuated bleomycin-induced lung fibrosis and cell senescence in mice. In summary, these data demonstrate that NR2F2 is involved in lung epithelial cell senescence, and targeting NR2F2 may be a promising therapeutic approach against lung cell senescence and fibrosis.

A WNT mimetic with broad spectrum FZD-specificity decreases fibrosis and improves function in a pulmonary damage model.

BACKGROUND: Wnt/ß-catenin signaling is critical for lung development and AT2 stem cell maintenance in adults, but excessive pathway activation has been associated with pulmonary fibrosis, both in animal models and human diseases such as idiopathic pulmonary fibrosis (IPF). IPF is a detrimental interstitial lung disease, and although two approved drugs limit functional decline, transplantation is the only treatment that extends survival, highlighting the need for regenerative therapies. METHODS: Using our antibody-based platform of Wnt/ß-catenin modulators, we investigated the ability of a pathway antagonist and pathway activators to reduce pulmonary fibrosis in the acute bleomycin model, and we tested the ability of a WNT mimetic to affect alveolar organoid cultures. RESULTS: A WNT mimetic agonist with broad FZD-binding specificity (FZD1,2,5,7,8) potently expanded alveolar organoids. Upon therapeutic dosing, a broad FZD-binding specific Wnt mimetic decreased pulmonary inflammation and fibrosis and increased lung function in the bleomycin model, and it impacted multiple lung cell types in vivo. CONCLUSIONS: Our results highlight the unexpected capacity of a WNT mimetic to effect tissue repair after lung damage and support the continued development of Wnt/ß-catenin pathway modulation for the treatment of pulmonary fibrosis.

[Exosomes derived from bone marrow mesenchymal stem cells regulate NF-κB pathway and reduce lung ischemia-reperfusion injury in rats by miR-335].

This study aimed to investigate the effect of exosomes derived from bone marrow mesenchymal stem cells (BMSCs-EXO) on lung ischemia-reperfusion injury (IRI) in rats and to explore the role of miR-335. The model of rat lung IRI was established by clipping the hilum of left lung for 60 min and opening for 180 min. Forty Sprague-Dawley rats were randomly divided into sham group, IRI group, IRI+PBS group, IRI+EXO group, and IRI+miR-335 inhibitor EXO (IRI+inhibitor-EXO) group (n = 8). Rats in the sham group underwent thoracotomies without IRI. Rats in the IRI group were used to establish IRI model without any additional treatment. In the IRI+PBS, IRI+EXO, and IRI+inhibitor-EXO groups, the rats were used to establish IRI model and given PBS, EXO from BMSCs without any treatment, and EXO from BMSCs with miR-335 inhibitor treatment before reperfusion, respectively. Blood gases were analyzed during the experiment. Lung tissue wet/dry ratio (W/D), interleukin 1ß (IL-1ß), tumor necrosis factor α (TNF-α), myeloperoxidase (MPO), malondialdehyde (MDA), and superoxide dismutase (SOD) were measured at the end of reperfusion. Mitochondria were observed by electron microscopy and the Flameng scores were counted. Lung histopathology and apoptosis (TUNEL staining) were observed by light microscopy, and the lung injury scores (LIS) and apoptosis index (AI) were detected. The miR-335 expression was detected by RT-qPCR, and the expression of caspase-3, cleaved-caspase-3, caspase-9, cleaved-caspase-9, and NF-κB proteins were detected by Western blot at the end of reperfusion. The results showed that compared with the sham group, the oxygenation index, pH, and base excess (BE) were significantly lower in the IRI group and IRI+PBS group after reperfusion, whereas those indices were significantly higher in the IRI+EXO group than those in the IRI+PBS group (P < 0.05). Compared with the sham group, there were significant increases in W/D, IL-1ß, TNF-α, MPO, MDA, LIS, AI, Flameng score, caspase-3, cleaved-caspase-3, caspase-9, and cleaved-caspase-9, however significant decreases in the SOD, miR-335 and NF-κB in the IRI group (P < 0.05). These indices in the IRI and IRI+PBS groups showed no significant differences. Compared with the IRI+PBS group, there were significant decreases in W/D, IL-1ß, TNF-α, MPO, MDA, LIS, AI, Flameng score, caspase-3, cleaved-caspase-3, caspase-9, and cleaved-caspase-9, however significant increases in the SOD, miR-335 and NF-κB in the IRI+EXO group (P < 0.05). While, the changes of the above mentioned indices were reversed in the IRI+inhibitor-EXO group compared with IRI+EXO group, which were still better than those in the IRI+PBS group (P < 0.05). The results suggest that BMSCs-EXO could attenuate lung IRI in rats, activate NF-κB pathway, and maintain mitochondrial stability by up-regulating miR-335.

Exhaled breath condensate contains extracellular vesicles (EVs) that carry miRNA cargos of lung tissue origin that can be selectively purified and analyzed.

Lung diseases, including lung cancer, are rising causes of global mortality. Despite novel imaging technologies and the development of biomarker assays, the detection of lung cancer remains a significant challenge. However, the lung communicates directly with the external environment and releases aerosolized droplets during normal tidal respiration, which can be collected, stored and analzsed as exhaled breath condensate (EBC). A few studies have suggested that EBC contains extracellular vesicles (EVs) whose microRNA (miRNA) cargos may be useful for evaluating different lung conditions, but the cellular origin of these EVs remains unknown. In this study, we used nanoparticle tracking, transmission electron microscopy, Western blot analyses and super resolution nanoimaging (ONi) to detect and validate the identity of exhaled EVs (exh-EVs). Using our customizable antibody-purification assay, EV-CATCHER, we initially determined that exh-EVs can be selectively enriched from EBC using antibodies against three tetraspanins (CD9, CD63 and CD81). Using ONi we also revealed that some exh-EVs harbour lung-specific proteins expressed in bronchiolar Clara cells (Clara Cell Secretory Protein [CCSP]) and Alveolar Type II cells (Surfactant protein C [SFTPC]). When conducting miRNA next generation sequencing (NGS) of airway samples collected at five different anatomic levels (i.e., mouth rinse, mouth wash, bronchial brush, bronchoalveolar lavage [BAL] and EBC) from 18 subjects, we determined that miRNA profiles of exh-EVs clustered closely to those of BAL EVs but not to those of other airway samples. When comparing the miRNA profiles of EVs purified from matched BAL and EBC samples with our three tetraspanins EV-CATCHER assay, we captured significant miRNA expression differences associated with smoking, asthma and lung tumor status of our subjects, which were also reproducibly detected in EVs selectively purified with our anti-CCSP/SFTPC EV-CATCHER assay from the same samples, but that confirmed their lung tissue origin. Our findings underscore that enriching exh-EV subpopulations from EBC allows non-invasive sampling of EVs produced by lung tissues.

Correlating transcription and protein expression profiles of immune biomarkers following lipopolysaccharide exposure in lung epithelial cells.

Universal and early recognition of pathogens occurs through recognition of evolutionarily conserved pathogen associated molecular patterns (PAMPs) by innate immune receptors and the consequent secretion of cytokines and chemokines. The intrinsic complexity of innate immune signaling and associated signal transduction challenges our ability to obtain physiologically relevant, reproducible and accurate data from experimental systems. One of the reasons for the discrepancy in observed data is the choice of measurement strategy. Immune signaling is regulated by the interplay between pathogen-derived molecules with host cells resulting in cellular expression changes. However, these cellular processes are often studied by the independent assessment of either the transcriptome or the proteome. Correlation between transcription and protein analysis is lacking in a variety of studies. In order to methodically evaluate the correlation between transcription and protein expression profiles associated with innate immune signaling, we measured cytokine and chemokine levels following exposure of human cells to the PAMP lipopolysaccharide (LPS) from the Gram-negative pathogen Pseudomonas aeruginosa. Expression of 84 messenger RNA (mRNA) transcripts and 69 proteins, including 35 overlapping targets, were measured in human lung epithelial cells. We evaluated 50 biological replicates to determine reproducibility of outcomes. Following pairwise normalization, 16 mRNA transcripts and 6 proteins were significantly upregulated following LPS exposure, while only five (CCL2, CSF3, CXCL5, CXCL8/IL8, and IL6) were upregulated in both transcriptomic and proteomic analysis. This lack of correlation between transcription and protein expression data may contribute to the discrepancy in the immune profiles reported in various studies. The use of multiomic assessments to achieve a systems-level understanding of immune signaling processes can result in the identification of host biomarker profiles for a variety of infectious diseases and facilitate countermeasure design and development.

[64Cu]Cu-PEG-FUD peptide for noninvasive and sensitive detection of murine pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease resulting in irreversible scarring within the lungs. However, the lack of biomarkers that enable real-time assessment of disease activity remains a challenge in providing efficient clinical decision-making and optimal patient care in IPF. Fibronectin (FN) is highly expressed in fibroblastic foci of the IPF lung where active extracellular matrix (ECM) deposition occurs. Functional upstream domain (FUD) tightly binds the N-terminal 70-kilodalton domain of FN that is crucial for FN assembly. In this study, we first demonstrate the capacity of PEGylated FUD (PEG-FUD) to target FN deposition in human IPF tissue ex vivo. We subsequently radiolabeled PEG-FUD with 64Cu and monitored its spatiotemporal biodistribution via µPET/CT imaging in mice using the bleomycin-induced model of pulmonary injury and fibrosis. We demonstrated [64Cu]Cu-PEG-FUD uptake 3 and 11 days following bleomycin treatment, suggesting that radiolabeled PEG-FUD holds promise as an imaging probe in aiding the assessment of fibrotic lung disease activity.