Inhalation of 2, 4-di-tert-butylphenol-Loaded micelles suppresses respiratory syncytial virus infection in mice

Human respiratory syncytial virus (RSV) is a common cause of respiratory infections in infants, young children, and elderly people. However, there are no effective treatments or vaccines available in most countries. In this study, we explored the anti-RSV potential of 2, 4-Di-tert-butylphenol (2, 4-DTBP), a compound derived from Houttuynia cordata Thunb. To overcome the poor solubility of 2, 4-DTBP, we encapsulated it in polymeric micelles and delivered it by inhalation. We found that 2, 4-DTBP-loaded micelles inhibited RSV infection in vitro and improved survival, lung pathology, and viral clearance in RSV-infected mice. Our results suggested that 2, 4-DTBP-loaded micelle is a promising novel therapeutic agent for RSV infection.

Resveratrol Attenuates Hyperoxia Lung Injury in Neonatal Rats by Activating SIRT1/PGC-1α Signaling Pathway

OBJECTIVES

 Our previous study showed that resveratrol (Res) attenuates apoptosis and mitochondrial dysfunction in alveolar epithelial cell injury induced by hyperoxia by activating the SIRT1/PGC-1α signaling pathway. In the present study, we investigated whether Res protects against hyperoxia-induced lung injury in neonatal rats by activating SIRT1/PGC-1α signaling pathway.

METHODS

 Naturally delivered neonatal rats were randomly divided into six groups: normoxia + normal saline, normoxia + dimethyl sulfoxide (DMSO), normoxia + Res, hyperoxia + normal saline, hyperoxia + DMSO, and hyperoxia + Res. Lung tissue samples were collected on postnatal days 1, 7, and 14. Hematoxylin and eosin staining was used to evaluate lung development. Dual-immunofluorescence staining, real-time polymerase chain reaction, and western blotting were used to evaluate the levels of silencing information regulator 2-related enzyme 1 (SIRT1), peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α), nuclear respiratory factor 1 (Nrf1), Nrf2, transcription factor A (TFAM) and citrate synthase, the number of mitochondrial DNA (mtDNA) and mitochondria, the integrity of mtDNA, and the expression of TFAM in mitochondria.

RESULTS

 We found that hyperoxia insulted lung development, whereas Res attenuated the hyperoxia lung injury. Res significantly upregulated the levels of SIRT1, PGC-1α, Nrf1, Nrf2, TFAM, and citrate synthase; promoted TFAM expression in the mitochondria; and increased the copy number of ND1 and the ratio of ND4/ND1.

CONCLUSION

 Our data suggest that Res attenuates hyperoxia-induced lung injury in neonatal rats, and this was achieved, in part, by activating the SIRT1/PGC-1α signaling pathway to promote mitochondrial biogenesis.

KEY POINTS

· Hyperoxia insulted lung development in neonatal rats.. · Resveratrol promoted mitochondrial biogenesis to attenuate hyperoxia lung injury in neonatal rats.. · Resveratrol, at least in part, promoted mitochondrial biogenesis by activating the SIRT1/PGC-1α signaling pathway..

Itaconic acid regulation of TFEB-mediated autophagy flux alleviates hyperoxia-induced bronchopulmonary dysplasia

BACKGROUND

Premature infants often require oxygen supplementation, which can elicit bronchopulmonary dysplasia (BPD) and lead to mitochondrial dysfunction. Mitochondria play important roles in lung development, in both normal metabolism and apoptosis. Enhancing our comprehension of the underlying mechanisms in BPD development can facilitate the effective treatments.

METHODS

Plasma samples from BPD and non-BPD infants were collected at 36 weeks post-menstrual age and used for metabolomic analysis. Based on hyperoxia-induced animal and cell models, changes in mitophagy and apoptosis were evaluated following treatment with itaconic acid (ITA). Finally, the mechanism of action of ITA in lung development was comprehensively demonstrated through rescue strategies and administration of corresponding inhibitors.

RESULTS

An imbalance in the tricarboxylic acid (TCA) cycle significantly affected lung development, with ITA serving as a significant metabolic marker for the outcomes of lung development. ITA improved the morphological changes in BPD rats, promoted SP-C expression, and inhibited the degree of alveolar type II epithelial cells (AEC II) apoptosis. Mechanistically, ITA mainly promotes the nuclear translocation of transcription factor EB (TFEB) to facilitate dysfunctional mitochondrial clearance and reduces apoptosis in AEC II cells by regulating autophagic flux.

CONCLUSION

The metabolic imbalance in the TCA cycle is closely related to lung development. ITA can improve lung development by regulating autophagic flux and promote the nuclear translocation of TFEB, implying its potential therapeutic utility in the treatment of BPD.

Cutting Edge: First Lung Infection Permanently Enlarges Lymph Nodes and Enhances New T Cell Responses

Humans experience frequent respiratory infections. Immunology and vaccinology studies in mice are typically performed in naive specific pathogen-free animals responding to their very first respiratory challenge. We found that the first respiratory infection induces lifelong enlargement of the lung-draining mediastinal lymph nodes (medLNs). Furthermore, infection-experienced medLNs supported better naive T cell surveillance and effector responses to new unrelated infections that exhibited more biased accumulation and memory establishment within the lung. Moreover, we observed that weight loss induced by influenza infection was substantially reduced in mice that had recovered from a previous unrelated respiratory viral challenge. These data show that the lack of infectious history and corresponding medLN hypoplasia in specific pathogen-free mice alter their immune response to lung infections. Preclinical vaccination and immunology studies should consider the previous infectious experience of the model organism.

Preventive effects of Ramelteon on bleomycin-induced pulmonary fibrosis in mice

Pulmonary fibrosis (PF) is a devastating lung disease that leads to impaired lung function and ultimately death. Several studies have suggested that melatonin, a hormone involved in regulating sleep-wake cycles, may be effective in improving PF. Ramelteon, an FDA-approved melatonin receptor agonist, has shown promise in exerting an anti-PF effect similar to melatonin. However, further investigations are required for illuminating the extent on its therapeutic benefits and the underlying molecular mechanisms. In this work, a mouse lung fibrosis model was built through intratracheal administration of bleomycin (BLM). Subsequently, the mice were administrated Ramelteon for a duration of 3 weeks to explore its efficacy and mechanism of action. Additionally, we utilized a TGF-β1-induced MRC-5 cell model to further investigate the molecular mechanism underlying ramelteon's effects. Functionally, Ramelteon partially abrogated TGF-β1-induced pulmonary fibrosis and reduced fibroblast proliferation, extracellular matrix deposition, and differentiation into myofibroblasts. In vivo experiments, ramelteon attenuated BLM-induced pulmonary fibrosis and collagen deposition. Mechanistically, ramelteon exerts its beneficial effect by alleviating translocation and expression of YAP1, a core component of Hippo pathway, from cytoplasm to nucleus; however, overexpression of YAP1 reversed this effect. In conclusion, our findings indicate that ramelteon can improve PF by regulating Hippo pathway and may become a potential candidate as a therapy to PF.

Preparation and evaluation of inhalable S-allylmercapto-N-acetylcysteine and nintedanib co-loaded liposomes for pulmonary fibrosis

Orally marketed products nintedanib (NDNB) and pirfenidone (PFD) for pulmonary fibrosis (PF) are administered in high doses and have been shown to have serious toxic and side effects. NDNB can cause the elevation of galectin-3, which activates the NF-κB signaling pathway and causes the inflammatory response. S-allylmercapto-N-acetylcysteine (ASSNAC) can alleviate the inflammation response by inhibiting the TLR-4/NF-κB signaling pathway. Therefore, we designed and prepared inhalable ASSNAC and NDNB co-loaded liposomes for the treatment of pulmonary fibrosis. The yellow, spheroidal co-loaded liposomes with a particle size of 98.32±1.98 nm and zeta potential of -22.5 ± 1.58 mV were produced. The aerodynamic fine particle fraction (FPF) and mass median aerodynamic diameter (MMAD) of NDNB were >50 % (81.14 %±0.22 %) and <5 μm (1.79 μm±0.06 μm) in the nebulized liposome solution, respectively. The results showed that inhalation improved the lung deposition and retention times of both drugs. DSPE-PEG 2000 in the liposome formulation enhanced the mucus permeability and reduced phagocytic efflux mediated by macrophages. ASSNAC reduced the mRNA over-expressions of TLR-4, MyD88 and NF-κB caused by NDNB, which could reduce the NDNB's side effects. The Masson's trichrome staining of lung tissues and the levels of CAT, TGF-β1, HYP, collagen III and mRNA expressions of Collagen I, Collagen III and α-SMA in lung tissues revealed that NDNB/Lip inhalation was more beneficial to alleviate fibrosis than oral NDNB. Although the dose of NDNB/Lip was 30 times lower than that in the oral group, the inhaled NDNB/Lip group had better or comparable anti-fibrotic effects to those in the oral group. According to the expressions of Collagen I, Collagen III and α-SMA in vivo and in vitro, the combination of ASSNAC and NDNB was more effective than the single drugs for pulmonary fibrosis. Therefore, this study provided a new scheme for the treatment of pulmonary fibrosis.

Endothelial RSPO3 mediates pulmonary endothelial regeneration by LGR4-dependent activation of β-catenin and ILK signaling pathways after inflammatory vascular injury

Endothelial repair is essential for restoring tissue fluid homeostasis following lung injury. R-spondin3 (RSPO3), a secreted protein mainly produced by endothelial cells (ECs), has shown its protective effect on endothelium. However, the specific mechanisms remain unknown. To explore whether and how RSPO3 regulates endothelial regeneration after inflammatory vascular injury, the role of RSPO3 in sepsis-induced pulmonary endothelial injury was investigated in EC-specific RSPO3 knockdown, inducible EC-specific RSPO3 deletion mice, EC-specific RSPO3 overexpression mice, systemic RSPO3-administration mice, in isolated mouse lung vascular endothelial cells (MLVECs), and in plasma from septic patients. Here we show that plasma RSPO3 levels are decreased in septic patients and correlated with endothelial injury markers and PaO2/FiO2 index. Both pulmonary EC-specific knockdown of RSPO3 and inducible EC-specific RSPO3 deletion inhibit pulmonary ECs proliferation and exacerbate ECs injury, whereas intra-pulmonary EC-specific RSPO3 overexpression promotes endothelial recovery and attenuates ECs injury during endotoxemia. We show that RSPO3 mediates pulmonary endothelial regeneration by a LGR4-dependent manner. Except for β-catenin, integrin-linked kinase (ILK)/Akt is also identified as a novel downstream effector of RSPO3/LGR4 signaling. These results conclude that EC-derived RSPO3 mediates pulmonary endothelial regeneration by LGR4-dependent activation of β-catenin and ILK signaling pathways after inflammatory vascular injury.

Lysophospholipid Acyltransferase 9 Promotes Emphysema Formation via Platelet-activating Factor

Cigarette smoking is known to be the leading cause of chronic obstructive pulmonary disease (COPD). However, the detailed mechanisms have not been elucidated. PAF (platelet-activating factor), a potent inflammatory mediator, is involved in the pathogenesis of various respiratory diseases such as bronchial asthma and COPD. We focused on LPLAT9 (lysophospholipid acyltransferase 9), a biosynthetic enzyme of PAF, in the pathogenesis of COPD. LPLAT9 gene expression was observed in excised COPD lungs and single-cell RNA sequencing data of alveolar macrophages (AMs). LPLAT9 was predominant and upregulated in AMs, particularly monocyte-derived AMs, in patients with COPD. To identify the function of LPLAT9/PAF in AMs in the pathogenesis of COPD, we exposed systemic LPLAT9-knockout (LPALT9-/-) mice to cigarette smoke (CS). CS increased the number of AMs, especially the monocyte-derived fraction, which secreted MMP12 (matrix metalloprotease 12). Also, CS augmented LPLAT9 phosphorylation/activation on macrophages and, subsequently, PAF synthesis in the lung. The LPLAT9-/- mouse lung showed reduced PAF production after CS exposure. Intratracheal PAF administration accumulated AMs by increasing MCP1 (monocyte chemoattractant protein-1). After CS exposure, AM accumulation and subsequent pulmonary emphysema, a primary pathologic change of COPD, were reduced in LPALT9-/- mice compared with LPLAT9+/+ mice. Notably, these phenotypes were again worsened by LPLAT9+/+ bone marrow transplantation in LPALT9-/- mice. Thus, CS-induced LPLAT9 activation in monocyte-derived AMs aggravated pulmonary emphysema via PAF-induced further accumulation of AMs. These results suggest that PAF synthesized by LPLAT9 has an important role in the pathogenesis of COPD.

Forsythiaside A alleviates acute lung injury by inhibiting inflammation and epithelial barrier damages in lung and colon through PPAR-γ/RXR-α complex

INTRODUCTION

Acute lung injury (ALI) is a lung disease characterized by inflammation and still requires further drug development. Forsythiaside A as the active compound of Forsythiae Fructus has the therapeutic potential for ALI.

OBJECTIVE

To investigate the mechanism of forsythiaside A in treating ALI through PPAR-γ and its conjugate RXR-α based on gut-lung axis.

METHODS

This study constructed in vitro and in vivo injury models using LPS and TNF-α. Forsythiaside A was used for the drug treatment, and RXR-α inhibitor UVI3003 was used to interfere with PPAR-γ/RXR-α complexes in the cells. HE staining was used for histopathological examination. Serum endotoxin contents were determined using limulus lysate kit. IHC staining and Western blot were conducted to assess the protein expressions. ELISA was applied to examine the content of pro-inflammatory cytokines in the cell supernatants. The protein interactions were analyzed via CO-IP.

RESULTS

In vivo results showed that forsythiaside A regulated PPAR-γ/RXR-α and inhibited TLR4/MAPK/NF-κB and MLCK/MLC2 signal pathways, thus inhibiting inflammation and epithelial barrier damages of lung and colon in ALI mice induced by intratracheal LPS. PPAR-γ/RXR-α were promoted by forsythiaside A in lungs, whereas inhibited by forsythiaside A in colons. Additionally, in vitro results showed that forsythiaside A suppressed inflammation and epithelial barrier damages in macrophages and lung/colon epithelial cells, by manipulating PPAR-γ/RXR-α to suppress the LPS- and TNF-α-induced activation of TLR4/MAPK/NF-κB and NF-κB/MLCK/MLC2 signal pathways. Moreover, further mechanism study indicated that forsythiaside A showed a cell-specific regulatory effect on PPAR-γ/RXR-α complex. Specifically, the PPAR-γ/RXR-α protein interactions were promoted by forsythiaside A in LPS-induced macrophages RAW264.7 and TNF-α-induced lung epithelial cells A549, but inhibited by forsythiaside A in TNF-α-induced colon epithelial cells SW620.

CONCLUSION

In the treatment of ALI, Forsythiaside A inhibited inflammation and epithelial barrier damages of lung and colon through its regulation on PPAR-γ/RXR-α complex.

The incidence and prognosis of other iatrogenic immunodeficiency-associated lymphoproliferative disorders of the lung related to methotrexate: A retrospective study

BACKGROUND AND OBJECTIVE

Other iatrogenic immunodeficiency-associated lymphoproliferative disorders (OIIA-LPD) are rare but well-known diseases that manifest during or after methotrexate (MTX) administration. Limited information is available on the clinical characteristics of OIIA-LPD of the lung because only a few cases have been reported. Thus, we aimed to assess the incidence and prognosis of patients with OIIA-LPD of the lung.

METHODS

Patients with OIIA-LPD of the lung treated at our institution between January 2008 and July 2020 were retrospectively analysed.

RESULTS

Among the 51 patients with OIIA-LPD, 16 (31.3%, 7 men, 9 women) had OIIA-LPD of the lung (median age, 69 [range, 63-82] years). Peripheral lesions were observed in 10 (62.5%), central lesions in two (12.5%), and both lesions in four (25.0%) patients. Nine of the 16 patients underwent bronchoscopic biopsy, seven were diagnosed (diagnostic yield, 77.8%) and, re-biopsy was performed in 2 patients. Eight (50.0%) patients had LPD and six (37.5%) had diffuse large B-cell lymphoma. In the 14 patients with confirmed treatment efficacy, the overall response rate to MTX withdrawal was 71.4%. However, chemotherapy was required in case of larger lesions (three patients). Death related to OIIA-LPD occurred in only one patient, and 11 of the 14 patients were alive during the study period (median follow-up time, 53.7 [range, 4.3-84.2] months).

CONCLUSION

The incidence of OIIA-LPD of the lung is 31.3% and higher than that reported previously. The treatment effect of MTX withdrawal seems to be sufficient; however, in some cases, chemotherapy may be required from the beginning.

Endothelial knockdown of the tumor suppressor, WWOX, increases inflammation in ventilator-induced lung injury

Chronic cigarette smoke exposure decreases lung expression of WWOX which is known to protect the endothelial barrier during infectious models of acute respiratory distress syndrome (ARDS). Proteomic analysis of WWOX-silenced endothelial cells (ECs) was done using tandem mass tag mass spectrometry (TMT-MS). WWOX-silenced ECs as well as those isolated from endothelial cell Wwox knockout (EC Wwox KO) mice were subjected to cyclic stretch (18% elongation, 0.5 Hz, 4 h). Cellular lysates and media supernatant were harvested for assays of cellular signaling, protein expression, and cytokine release. These were repeated with dual silencing of WWOX and zyxin. Control and EC Wwox KO mice were subjected to high tidal volume ventilation. Bronchoalveolar lavage fluid and mouse lung tissue were harvested for cellular signaling, cytokine secretion, and histological assays. TMT-MS revealed upregulation of zyxin expression during WWOX knockdown which predicted a heightened inflammatory response to mechanical stretch. WWOX-silenced ECs and ECs isolated from EC Wwox mice displayed significantly increased cyclic stretch-mediated secretion of various cytokines (IL-6, KC/IL-8, IL-1β, and MCP-1) relative to controls. This was associated with increased ERK and JNK phosphorylation but decreased p38 mitogen-activated kinases (MAPK) phosphorylation. EC Wwox KO mice subjected to VILI sustained a greater degree of injury than corresponding controls. Silencing of zyxin during WWOX knockdown abrogated stretch-induced increases in IL-8 secretion but not in IL-6. Loss of WWOX function in ECs is associated with a heightened inflammatory response during mechanical stretch that is associated with increased MAPK phosphorylation and appears, in part, to be dependent on the upregulation of zyxin.NEW & NOTEWORTHY Prior tobacco smoke exposure is associated with an increased risk of acute respiratory distress syndrome (ARDS) during critical illness. Our laboratory is investigating one of the gene expression changes that occurs in the lung following smoke exposure: WWOX downregulation. Here we describe changes in protein expression associated with WWOX knockdown and its influence on ventilator-induced ARDS in a mouse model.

P75NTR+CD64+ neutrophils promote sepsis-induced acute lung injury

Patients suffering from sepsis-induced acute lung injury (ALI) exhibit a high mortality rate, and their prognosis is closely associated with infiltration of neutrophils into the lungs. In this study, we found a significant elevation of CD64+ neutrophils, which highly expressed p75 neurotrophin receptor (p75NTR) in peripheral blood of mice and patients with sepsis-induced ALI. p75NTR+CD64+ neutrophils were also abundantly expressed in the lung of ALI mice induced by lipopolysaccharide. Conditional knock-out of the myeloid lineage's p75NTR gene improved the survival rates, attenuated lung tissue inflammation, reduced neutrophil infiltration and enhanced the phagocytic functions of CD64+ neutrophils. In vitro, p75NTR+CD64+ neutrophils exhibited an upregulation and compromised phagocytic activity in blood samples of ALI patients. Blocking p75NTR activity by soluble p75NTR extracellular domain peptide (p75ECD-Fc) boosted CD64+ neutrophils phagocytic activity and reduced inflammatory cytokine production via regulation of the NF-κB activity. The findings strongly indicate that p75NTR+CD64+ neutrophils are a novel pathogenic neutrophil subpopulation promoting sepsis-induced ALI.

A multi-lesional analysis of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: a single-centre analysis

AIM

To conduct a multi-lesional computed tomography (CT) analysis of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) patients to determine volumetric changes in lesions over 5 years.

MATERIALS AND METHODS

A retrospective case-note review was undertaken to identify 16 patients with histological and radiological features of DIPNECH between 2012-2021. Area and volume were calculated for 17 sets of lesions identified on high-resolution CT. Clinical data were extracted from electronic patient records, which included demographic data, outpatient clinic letters, histology reports, and imaging reports.

RESULTS

One hundred and twenty-eight lesions were identified in 16 patients (one male, 15 female) and followed-up annually over a median 1,985 days (range 1,450-2,290). At year 1 follow-up, lesion area ranged from 1-48 mm2, and lesion volume ranged from 8-18,380 mm3; lesion area ranged from 1-45mm2 and lesion volume ranged from 11-17,800 mm3 and year 5. Half (8/16) of the patients had concomitant typical carcinoid tumours and one patient had an atypical carcinoid tumour. No statistically significant correlation (p<0.05) was found between lesion cross-sectional area or volume and duration of follow-up (years and days). No metastatic spread was observed at the time of analysis.

CONCLUSIONS

No significant increase was observed in the size of over 100 lesions in patients with DIPNECH over a 5-year period and no metastasis occurred during the study period affirming the relatively indolent course of the disease.

Clinical Significance of Preserving Pulmonary Function After Lung Resection in Early-Stage Non-Small-Cell Lung Cancer

INTRODUCTION

To determine the association between changes in pulmonary function before and after surgery, and the subsequent prognosis, of patients with early-stage non-small-cell lung cancer (NSCLC).

METHODS

A total of 485 patients who underwent lobectomy or segmentectomy for NSCLC with whole tumor size ≤2 cm and clinical stage IA at 2 institutions were retrospectively reviewed. The relationship between the postoperative reduction rate in vital capacity (VC), forced vital capacity (FVC), and forced expiratory volume in 1 second (FEV1) and overall survival (OS) was investigated. OS determined the cut-off value of the reduction rate, according to the reduction rate of every 10% in pulmonary function.

RESULTS

Multivariable Cox regression analysis showed that a reduction rate in VC at 12 months postoperatively was an independent prognostic factor for OS (hazard ratio, 1.05; 95% confidence interval [CI], 1.02-1.07; P < .001) but those in FVC and FEV1 were not. OS was classified into good and poor with 20% reduction rate in VC. OS and recurrence-free survival (RFS) in a higher than 20% reduction rate in VC were worse than those in ≤20% reduction rate in VC (5 year-OS; 82.0% vs. 93.4%; P = .0004. Five year-RFS; 80.3% vs. 89.8%; P = .0018, respectively). Multivariable logistic analysis showed that lobectomy was a risk factor for the higher than 20% reduction rate in VC (odds ratio, 1.61; 95% CI, 1.01-2.56; P = .045).

CONCLUSIONS

Postoperative decrease in VC was significantly associated with the prognosis. Preserving pulmonary function is important for survival of patients with early-stage NSCLC.

Correlation between the dynamic changes of γδT cells, Th17 cells, CD4+CD25+ regulatory T cells in peripheral blood and pharmacological interventions against bleomycin-induced pulmonary fibrosis progression in mice

The involvement of γδT cells, Th17 cells, and CD4+CD25+ regulatory T cells (Tregs) is crucial in the progression of pulmonary fibrosis (PF), particularly in maintaining immune tolerance and homeostasis. However, the dynamics of these cells in relation to PF progression, especially under pharmacological interventions, remains poorly understood. This study aims to unravel the interplay between the dynamic changes of these cells and the effect of pharmacological agents in a mouse model of PF induced by intratracheal instillation of bleomycin. We analyzed changes in lung histology, lung index, hydroxyproline levels, and the proportions of γδT cells, Th17 cells, and Tregs on the 3rd, 14th, and 28th days following treatment with Neferine, Isoliensinine, Pirfenidone, and Prednisolone. Our results demonstrate that these drugs can partially or dynamically reverse weight loss, decrease lung index and hydroxyproline levels, and ameliorate lung histopathological damage. Additionally, they significantly modulated the abnormal changes in γδT, Th17, and Treg cell proportions. Notably, on day 3, the proportion of γδT cells increased in the Neferine and Prednisolone groups but decreased in the Isoliensinine and Pirfenidone groups, while the proportion of Th17 cells decreased across all treated groups. On day 14, the Neferine group showed an increase in all three cell types, whereas the Pirfenidone group exhibited a decrease. In the Isoliensinine group, γδT and Th17 cells increased, and in the Prednisolone group, only Tregs increased. By day 28, an increase in Th17 cell proportion was observed in all treatment groups, with a decrease in γδT cells noted in the Neferine group. These shifts in cell proportions are consistent with the pathogenesis changes induced by these anti-PF drugs, suggesting a correlation between cellular dynamics and pharmacological interventions in PF progression. Our findings imply potential strategies for assessing the efficacy and timing of anti-PF treatments based on these cellular changes.

Generation of a humanized mAce2 and a conditional hACE2 mouse models permissive to SARS-COV-2 infection

The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) remains a public health concern and a subject of active research effort. Development of pre-clinical animal models is critical to study viral-host interaction, tissue tropism, disease mechanisms, therapeutic approaches, and long-term sequelae of infection. Here, we report two mouse models for studying SARS-CoV-2: A knock-in mAce2F83Y,H353K mouse that expresses a mouse-human hybrid form of the angiotensin-converting enzyme 2 (ACE2) receptor under the endogenous mouse Ace2 promoter, and a Rosa26 conditional knock-in mouse carrying the human ACE2 allele (Rosa26hACE2). Although the mAce2F83Y,H353K mice were susceptible to intranasal inoculation with SARS-CoV-2, they did not show gross phenotypic abnormalities. Next, we generated a Rosa26hACE2;CMV-Cre mouse line that ubiquitously expresses the human ACE2 receptor. By day 3 post infection with SARS-CoV-2, Rosa26hACE2;CMV-Cre mice showed significant weight loss, a variable degree of alveolar wall thickening and reduced survival rates. Viral load measurements confirmed inoculation in lung and brain tissues of infected Rosa26hACE2;CMV-Cre mice. The phenotypic spectrum displayed by our different mouse models translates to the broad range of clinical symptoms seen in the human patients and can serve as a resource for the community to model and explore both treatment strategies and long-term consequences of SARS-CoV-2 infection.

Toxic effect and mRNA mechanism of moon dust simulant induced pulmonary inflammation in rats

Moon dust presents a significant hazard to manned moon exploration missions, yet our understanding of its toxicity remains limited. The objective of this study is to investigate the pattern and mechanism of lung inflammation induced by subacute exposure to moon dust simulants (MDS) in rats. SD rats were exposed to MDS and silica dioxide through oral and nasal inhalation for 6 hours per day continuously for 15 days. Pathological analysis indicated that the toxicity of MDS was lower than that of silica dioxide. MDS led to a notable recruitment and infiltration of macrophages in the rat lungs. Material characterization and biochemical analysis revealed that SiO2, Fe2O3, and TiO2 could be crucial sources of MDS toxicity. The study revealed that MDS-induced oxidative stress response can lead to pulmonary inflammation, which potentially may progress to lung fibrosis. Transcriptome sequencing revealed that MDS suppresses the PI3K-AKT signaling pathway, triggers the Tnfr2 non-classical NF-kB pathway and IL-17 signaling pathway, ultimately causing lung inflammation and activating predominantly antioxidant immune responses. Moreover, the study identified the involvement of upregulated genes IL1b, csf2, and Sod2 in regulating immune responses in rat lungs, making them potential key targets for preventing pulmonary toxicity related to moon dust exposure. These findings are expected to aid in safeguarding astronauts against the hazardous effects of moon dust and offer fresh insights into the implications and mechanisms of moon dust toxicity.

Effect of Hypertonic Saline Solution on the Ventilatory Mechanics of Lungs Donated After Brain Death

INTRODUCTION

Brain death (BD) compromises the viability of the lung for donation. Hypertonic saline solution (HSS) induces rapid intravascular volume expansion and immunomodulatory action. We investigated its role in ventilatory mechanics (VMs) and in the inflammatory activity of the lungs of rats subjected to BD.

METHODS

Wistar rats were divided into four groups: control, n = 10: intact rats subjected to extraction of the heart-lung block; BD, n = 8 (BD): rats treated with isotonic saline solution (4 mL/kg) immediately after BD; hypertonic saline 0 h, n = 9 (Hip.0'): rats treated with HSS (4 mL/kg) immediately after BD; and hypertonic saline 1 h, n = 9 (Hip.60'), rats treated with HSS (4 mL/kg) 60 min after BD. The hemodynamic characteristics, gas exchange, VMs, inflammatory mediators, and histopathological evaluation of the lung were evaluated over 240 min of BD.

RESULTS

In VMs, we observed increased airway resistance, tissue resistance, tissue elastance, and respiratory system compliance in the BD group (P < 0.037), while the treated groups showed no impairment over time (P > 0.05). In the histological analysis, the BD group showed a greater area of perivascular edema and a higher neutrophil count than the control group and the Hip.60' group (P < 0.05).

CONCLUSIONS

Treatment with HSS was effective in preventing changes in the elastic and resistive pulmonary components, keeping them at baseline levels. Late treatment reduced perivascular and neutrophilic edema in lung tissue.

Overcoming the Challenge of Accurate Segmentation of Lung Nodules: A Multi-crop CNN Approach

Lung nodules are generated based on the growth of small and round- or oval-shaped cells in the lung, which are either cancerous or non-cancerous. Accurate segmentation of these nodules is crucial for early detection and diagnosis of lung cancer. However, lung nodules can have various shapes, sizes, and densities, making their accurate segmentation a difficult task. Moreover, they can be easily confused with other structures in the lung, including blood vessels and airways, further complicating the segmentation process. To address this challenge, this paper proposes a novel multi-crop convolutional neural network (multi-crop CNN) model that utilizes different sized cropped regions of CT scan images for accurate segmentation of lung nodules. The model consists of three modules, namely the feature representation module, boundary refinement module, and segmentation module. The feature representation module captures features from the lung CT scan image using cropped regions of different sizes, while the boundary refinement module combines the boundary maps and feature maps to generate a final feature map for the segmentation process. The segmentation module produces a high-resolution segmentation map that shows improved accuracy in segmenting cancerous lung nodules. The proposed multi-crop CNN model is evaluated on two segmentation datasets namely LUNA 16 and LIDC-IDRI with an accuracy of 98.3% and 98.5%, respectively. The performances are measured in terms of accuracy, recall, precision, dice coefficient, specificity, AUC/ROC, Hausdorff distance, Jaccard index, and average Hausdorff. Overall, the proposed multi-crop CNN model demonstrates the potential to enhance the lung nodule segmentation accuracy, which could lead to earlier detection and diagnosis of lung cancer and ultimately reduce mortality rates associated with the disease.

Specneuzhenide improves bleomycin-induced pulmonary fibrosis in mice via AMPK-dependent reduction of PD-L1

BACKGROUND

Pulmonary fibrosis (PF) is an escalating global health issue, characterized by rising rates of morbidity and mortality annually. Consequently, further investigation of potential damage mechanisms and potential preventive strategies for PF are warranted. Specnuezhenide (SPN), a prominent secoiridoid compound derived from Ligustrum lucidum Ait, exhibits anti-inflammatory and anti-oxidative capacities, indicating the potential therapeutic actions on PF. However, the underlying mechanisms of SPN on PF remain unclear.

PURPOSE

This work was aimed at investigating the protective actions of SPN on PF and the potential mechanism.

METHODS

In vivo, mice were administrated with bleomycin (BLM) to establish PF model. PF mice were treated with SPN (45/90 mg/kg) by gavage. In vitro, we employed TGF-β1 (10 ng/mL)-induced MLE-12 and PLFs cells, which then were treated with SPN (5, 10, 20 µM). DARTS assay, biofilm interference experiment and molecular docking were performed to investigate the molecular target of SPN.

RESULTS

In vivo, we found SPN treatment improved survival rate, alleviated pathological changes through reducing BLM-induced extracellular matrix (ECM) deposition, as well as BLM-induced epithelial-mesenchymal transition (EMT). In vitro, SPN inhibited EMT and lung fibroblast transdifferentiation. Mechanistically, SPN activated the AMPK protein to decrease the abnormally high level of PD-L1. Furthermore, the compound C, known as an AMPK inhibitor, exhibited a significant hindrance to the inhibition of SPN on TGF-β1-caused fibroblast transdifferentiation and proliferation. This outcome could be attributed to the fact that compound C could eliminate the inhibitory effects of SPN on PD-L1 expression. Interestingly, DARTS assay, biofilm interference experiment and molecular docking results all indicated that SPN could bind to AMPK, which suggested that SPN might be a potential agonist targeting AMPK protein.

CONCLUSION

Altogether, the results in our work illustrated that SPN promoted AMPK-dependent reduction of PD-L1 protein, contributing to the inhibition of fibrosis progression. Thus, SPN may represent a potential AMPK agonist for PF treatment.

Smoking-Related Interstitial Lung Disease: Historical Perspective and Advances in the Twenty-first Century

In the twenty- first century, there is widespread agreement that in addition to lung cancer, emphysema, and chronic bronchitis, cigarette smoking causes accumulation of pigmented macrophages, interstitial fibrosis, and Langerhans cell proliferation in various permutations. These histologic changes remain subclinical in some patients and produce clinical manifestations and imaging abnormalities in others. Debate surrounds terminology of these lesions, which are often grouped together under the umbrella of "smoking-related interstitial lung disease." This review summarizes modern concepts in our understanding of these abnormalities and explains how the recognition of smoking-related interstitial fibrosis has advanced the field.