Pulmonary Alveolar Research Articles

Floxed Il1rl2 Locus with mCherry Reporter Element Reveals Distinct Expression Patterns of the IL-36 Receptor in Barrier Tissues.

IL-36 cytokines are emerging as beneficial in immunity against pathogens and cancers but can also be detrimental when dysregulated in autoimmune and autoinflammatory conditions. Interest in targeting IL-36 activity for therapeutic purposes is rapidly growing, yet many unknowns about the functions of these cytokines remain. Thus, the availability of robust research tools is essential for both fundamental basic science and pre-clinical studies to fully access outcomes of any manipulation of the system. For this purpose, a floxed Il1rl2, the gene encoding the IL-36 receptor, mouse strain was developed to facilitate the generation of conditional knockout mice. The targeted locus was engineered to contain an inverted mCherry reporter sequence that upon Cre-mediated recombination will be flipped and expressed under the control of the endogenous Il1rl2 promoter. This feature can be used to confirm knockout in individual cells but also as a reporter to determine which cells express the IL-36 receptor IL-1RL2. The locus was confirmed to function as intended and further used to demonstrate the expression of IL-1RL2 in barrier tissues. Il1rl2 expression was detected in leukocytes in all barrier tissues. Interestingly, strong expression was observed in epithelial cells at locations in direct contact with the environment such as the skin, oral mucosa, the esophagus, and the upper airways, but almost absent from epithelial cells at more inward facing sites, including lung alveoli, the small intestine, and the colon. These findings suggest specialized functions of IL-1RL2 in outward facing epithelial tissues and cells. The generated mouse model should prove valuable in defining such functions and may also facilitate basic and translational research.

Cytokine profiles associated with disease severity and prognosis of autoimmune pulmonary alveolar proteinosis

BackgroundPulmonary alveolar proteinosis (PAP) is characterized by an abnormal accumulation of surfactants in the alveoli. Most cases are classified as autoimmune PAP (APAP) because they are associated with autoantibodies against granulocyte-macrophage colony-stimulating factor (GM-CSF). However, GM-CSF autoantibody levels are unlikely to correlate with the disease severity or prognosis of APAP. MethodsWe collected clinical records and measured 38 serum cytokine concentrations for consecutive patients with APAP. After exclusion of 21 cytokines because of undetectable levels, 17 cytokine levels were compared between low and high disease severity scores (DSSs). We also compared whole lung lavage (WLL)-free survival with cut-off values defined by receiver operating characteristic (ROC) curves of cytokine levels and WLL administration at 11 months. ResultsNineteen patients with APAP were enrolled in the study. Five were classified as DSS 1 or 2, while the others were classified as DSS 4 or 5. Comparison between DSS 1−2 and 4−5 revealed that the concentrations of IP-10 and GRO increased in the latter groups (p < 0.05). Fifteen patients underwent WLL. Comparison between those who underwent WLL within 11 months and the others showed that IP-10 and TNF-α were tended to be elevated in the former group (p = 0.082 and 0.057, respectively). The cut-off values of IP-10, 308.8 pg/mL and TNF-α, 19.1 pg/mL, defined by the ROC curves, significantly separated WLL-free survivals with log-rank analyses (p = 0.005). ConclusionsThe concentrations of IP-10 and GRO may reflect the DSSs of APAP. A combination of IP-10 and TNF-α levels could be a biomarker to predict WLL-free survival.

Chemical composition, antioxidant, antimicrobial and anti-proliferative activities of the leaf essential oil of Melaleuca polandii grown in the coastal plains of eastern India

Melaleuca polandii, commonly known as “Gold-tipped Bottlebrush”, is widely grown in Indian gardens and parks as an ornamental plant. In the present study, the chemical composition, antioxidant, antimicrobial and cytotoxic activities of M. polandii leaf essential oil (MPLEO) have been investigated. GC-MS analysis of MPLEO isolated from plants grown along the coastal plains of Eastern India revealed the presence of 50 constituents with α-pinene (46.17%), 3Z-hexenyl acetate (10.10 %), α-terpineol (5.43%), limonene (3.63%) and ρ-cymene (2.44 %) as the major constituents. MPLEO exhibited moderate antioxidant capacity in DPPH, ABTS and Reducing ability assays with IC50 values of 7.94 ± 0.34 μg/mL, 5.71 ± 0.21 μg/mL and EC50 7.09 ± 0.35 μg/mL, respectively. Of the 5 bacterial strains tested, the EO exhibited highest sensitivity against Bacillus subtilis with the ZOI of 12.66 ± 0.57 mm and strong antimicrobial activity against Staphylococcus saprophyticus with MIC value of 6.25 μg/mL. MPLEO exhibited significant cytotoxic effects against Human alveolar lung adenocarcinoma (A549), Human hepato-cellular carcinoma (HepG2), Human cervix adenocarcinoma (HeLa) and normal Human Embryonic Kidney cell (HEK-293) as evaluated through MTT assay with IC50 values of 9.5 ± 0.38 μg/mL, 22.73 ± 0.95 μg/mL, 20.41 ± 0.82 μg/mL and 237.68 ± 9.26 μg/mL, respectively. The findings of the present study demonstrated that MPLEO could be considered as a potential bioresource having applications in pharmaceutical industries as an antibacterial and antiproliferative agent.

High-magnitude cyclic stretch induces protein sialylation and RNA de-sialylation at the alveolar epithelial membrane

Sialylated glycans such as sialoglycoproteins, sialoglycolipids and sialoglycoRNA are ubiquitous in the glycocalyx of cells where they play a key role in barrier function, mechanosensation, infection, immune cell traffcking, and inflammation. These functions are particularly relevant at the blood-gas barrier of the lung. The alveolar epithelial glycocalyx is furthermore unique in that it is constantly exposed to cyclic stretch because of normal breathing. Yet, the abundance, regulation and function of sialylated glycans in the alveolar epithelial glycocalyx remains unknown. Here, we focused on the effects of mechanical stretch on the abundance and de novo formation of sialoglyco-proteins and -RNA as major constituents of the alveolar epithelial sialome. Human primary alveolar epithelial cells (hPAEpiC) were exposed to high magnitude cyclic stretch (18% CS) at 0.25 Hz for 24-48 hours to mimic biomechanical forces at the alveolar epithelium during high tidal volume ventilation. Total sialic acids in sialoglycoproteins were labeled with biotin by periodate oxidation and aldehyde ligation (pAL), and total sialic acids in sialoglycoRNA were quantified by 1, 2-diamino-4,5-methylene dioxybenzene ( DMB) assay. De novo formed sialic acids were labeled with biotin using N-azidoacetyl-mannosamine (Ac4ManNAz). Biotinylated siaolglyco-proteins and -RNAs were detected with streptavidin by Western and Northern blots, respectively, and quantified densitometrically. Stretch-dependent changes in the genes regulating sialic acid biosynthesis were assessed by RNA sequencing. High magnitude cyclic stretch increased the sialylation of proteins of different sizes (35-190 kDa) in the hPAEpiC glycocalyx. MGE showed this increase to be attributable to an increased de novo synthesis of sialic acids. On the other hand, high magnitude cyclic stretch reduced the sialylation of hPAEpiC sialoglycoRNA with no alteration in de novo synthesis, suggesting shedding, release or loss of sialoglycoRNA. RNA seq of hPAEpiC revealed that cyclic stretch upregulated the gene GNE (which encodes the enzyme UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase), the master regulator of sialic acid biosynthesis. Here, we demonstrate cyclic stretch-induced sialylation of proteins and de-sialylation of RNA in the alveolar epithelial glycocalyx. Given that sialic acids promote the adhesion of both infectious pathogens and immune cells, these effects may contribute to the pathogenesis of ventilator-associated pneumonia and ventilator-induced lung injury. This work is supported by the German Research Foundation, CRC 1449 subproject B01 to MO &amp; WMK. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Determination of surfactant secretion in precision-cut lung slices

Surfactant, secreted from type 2 (AT2) cells of the alveolar epithelium (AE), maintains alveolar stability. However, the variability of surfactant secretion, a possible cause of regional lung disease, remains unquantified. To address this, we cultured precision-cut lung slices (PCLS) of mouse lung explants, using low-melting point agarose as per reported protocols. For real-time confocal imaging (RCM), we loaded day-old PCLS with the cytosolic marker calcein green (CG) and the AT2 cell marker, lysotracker red (LTR). RCM revealed alveoli as CG-stained AE that circumscribed the non-fluorescent alveolar lumen. Each slice (n=3) contained &gt;300 alveoli, each with an LTR+ AT2 cell. Exposing the slice to ATPgamma-s (4 microM) induced progressive loss of LTR fluorescence, denoting induction of surfactant secretion. In 60% of AT2 cells, the fluorescence decreased to 40±2% of initial in 50 min (p&lt;0.01). In 11%, the decrease was to 59±1%. In 29%, there was no decrease. We conclude: (i) PCLS provide a robust platform for quantifying AT2 secretion; (ii) surfactant secretion rates vary considerably amongst AT2 cells. Mechanistic basis of the variation, hence its impact on lung function must be understood. HL36024. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Lung infection with classical Klebsiella pneumoniae strains establishes robust macrophage-dependent protection against heterologous reinfection

At present, there is no approved vaccine for prevention of infection by the opportunistic bacterium Klebsiella pneumoniae (Kp); success in treating these infections is increasingly challenged by the spread of antibiotic resistance. Preclinical investigation of adaptive immunity elicited by lung infection with live classical Kp may reveal host mechanisms of protection against this pathogen. Here, we utilize multiple virulent classical Kp strains to demonstrate that following lung infection, surviving wild-type mice develop protective immunity against both homologous and heterologous (heterotypic) reinfection. For Kp strains with low capacity to disseminate from the lung, this immunity is B-cell-independent. We further demonstrate that this immune protection is also effective against subsequent challenge with hypervirulent Kp if the strains share the same capsule type. Systemic inoculation fails to elicit the same protective effect as lung inoculation, revealing a lung-specific immune effector function is responsible for this protection. We therefore utilized clodronate-loaded liposomes to substantially deplete both alveolar macrophages and lung interstitial macrophages, finding that simultaneous depletion of both subsets entirely ablates protection. These findings indicate that following initial lung infection with Kp, lung macrophages mediate protection against ensuing Kp challenge.

Pulmonary Alveolar Proteinosis Secondary to Chronic Ethylene Oxide Occupational Inhalation

In this case report, a 40-year-old male patient with a persistent and productive cough lasting over 2 weeks, accompanied by dyspnea, who received an anti-tuberculosis drug regimen for 12 months without any clinical improvement at a different hospital before being referred to Persahabatan Central General Hospital was presented. In-depth clinical, and radiological investigations, the periodic acid-Schiff (PAS)-positive related to pulmonary alveolar proteinosis (PAP) confirmed through transbronchial biopsy (TBB). PAP is a rare lung disease with exceptionally low prevalence and incidence, Notably, the patient’s occupational environment played a crucial role in the diagnosis, as we identified occupational PAP secondary to chronic inhalation of ethylene oxide in a poorly ventilated work setting and inadequate respiratory protection. The patient was administered inhaled filgrastim (1 vial) at four intervals over 30 days, yielding favorable and satisfactory clinical as well as radiological outcomes.

Computed Tomographic Study of Frontal Sinus Cells and Opacification as Per the International Frontal Sinus Anatomy Classification.

International frontal sinus anatomy classification (IFAC) was introduced in 2016 to standardize the nomenclature of the cells in the frontal recess region, facilitate better communication between surgeons and precision in surgical planning, and improve surgical teaching. This study aims to estimate the radiological prevalence of the different frontal recess cells according to the IFAC and to evaluate the relationship of these cells with the frontal sinus opacification in patients with chronic rhinosinusitis. In this study, 90 participants diagnosed with chronic rhinosinusitis (CRS) who underwent computed tomogram (CT) of the para nasal sinuses were enrolled consecutively. The CT images were were studied in detail using RadiAnt DICOM viewer. The frontal recess cells were grouped as per the IFAC guidelines and their respective prevalence was calculated. The frontal recess cells were grouped as per the Opacification or mucosal thickening within these cells and the frontal sinuses were noted. A multivariate logistic regression analysis was done to evaluate the association between frontal sinus opacification and presence of various IFAC cells. A total of 640 IFAC cells were documented in 180 sides, of which 326 were anterior cells, 263 were posterior cells and 51 were medial cells. The most prevalent cell was the agger nasi cells(ANC), present in 91.7% of 180 sides, the supra agger nasi cells(SANC), Supra agger nasi frontal cells(SAFC), supra bulla cells(SBC), supra bulla frontal cells(SBFC), supra orbital ethmoidal cells(SOEC) and frontal septal cells(FSC) were present in 47.8%,37.8%, 65.6%,28.9%, 51.1% and 28.3% respectively. There was no significant association of presence of IFAC cells and frontal sinus opacification except for SBFC(p = 0.038). A significantly higher number of diseased frontal recess cells were seen with involved frontal sinuses when compared with non-involved frontal sinuses across all types of IFAC cells. The ANC were the most prevalent among all the IFAC cells and the FSC were the least prevalent. There was no significant association with the presence of different types of IFAC cells and frontal sinus opacification except for SBFC. However, there was a significantly higher number of diseased IFAC cells associated with frontal sinus opacification than in those without frontal sinus opacification.

Mimosa pudica L. extract ameliorates pulmonary fibrosis via modulation of MAPK signaling pathways and FOXO3 stabilization

Ethnopharmacological relevanceIdiopathic pulmonary fibrosis (IPF) is a progressive fibrosing pulmonary disorder that has a poor prognosis and high mortality. Although there has been extensive effort to introduce several new anti-fibrotic agents in the past decade, IPF remains an incurable disease. Mimosa pudica L., an indigenous Vietnamese plant, has been empirically used to treat respiratory disorders. Nevertheless, the therapeutic effects of M. pudica (MP) on lung fibrosis and the mechanisms underlying those effects remain unclear. Aim of the studyThis study investigated the protective effect of a crude ethanol extract of the above-ground parts of MP against pulmonary fibrogenesis. Materials and methodsInflammatory responses triggered by TNFα in structural lung cells were examined in normal human lung fibroblasts and A549 alveolar epithelial cells using Western blot analysis, reverse transcription–quantitative polymerase chain reaction assays, and immunocytochemistry. The epithelial-to-mesenchymal transition (EMT) was examined via cell morphology observations, F-actin fluorescent staining, gene and protein expression measurements, and a wound-healing assay. Anti-fibrotic assays including collagen release, differentiation, and measurements of fibrosis-related gene and protein expression levels were performed on TGFβ-stimulated human lung fibroblasts and lung fibroblasts derived from mice with fibrotic lungs. Finally, in vitro anti-fibrotic activities were validated using a mouse model of bleomycin-induced pulmonary fibrosis. ResultsMP alleviated the inflammatory responses of A549 alveolar epithelial cells and lung fibroblasts, as revealed by inhibition of TNFα-induced chemotactic cytokine and chemokine expression, along with inactivation of the MAPK and NFκB signalling pathways. MP also partially reversed the TGFβ-promoted EMT via downregulation of mesenchymal markers in A549 cells. Importantly, MP decreased the expression levels of fibrosis-related genes/proteins including collagen I, fibronectin, and αSMA; moreover, it suppressed collagen secretion and prevented myofibroblast differentiation in lung fibroblasts. These effects were mediated by FOXO3 stabilization through suppression of TGFβ-induced ERK1/2 phosphorylation. MP consistently protected mice from the onset and progression of bleomycin-induced pulmonary fibrosis. ConclusionThis study explored the multifaceted roles of MP in counteracting the pathobiological processes of lung fibrosis. The results suggest that further evaluation of MP could yield candidate therapies for IPF.

Downregulation of HMGCS2 mediated AECIIs lipid metabolic alteration promotes pulmonary fibrosis by activating fibroblasts

BackgroundAbnormal lipid metabolism has recently been reported as a crucial signature of idiopathic pulmonary fibrosis (IPF). However, the origin and biological function of the lipid and possible mechanisms of increased lipid content in the pathogenesis of IPF remains undetermined.MethodsOil-red staining and immunofluorescence analysis were used to detect lipid accumulation in mouse lung fibrosis frozen sections, Bleomycin-treated human type II alveolar epithelial cells (AECIIs) and lung fibroblast. Untargeted Lipid omics analysis was applied to investigate differential lipid species and identified LysoPC was utilized to treat human lung fibroblasts and mice. Microarray and single-cell RNA expression data sets identified lipid metabolism-related differentially expressed genes. Gain of function experiment was used to study the function of 3-hydroxy-3-methylglutaryl-Coa Synthase 2 (HMGCS2) in regulating AECIIs lipid metabolism. Mice with AECII-HMGCS2 high were established by intratracheally delivering HBAAV2/6-SFTPC- HMGCS2 adeno-associated virus. Western blot, Co-immunoprecipitation, immunofluorescence, site-directed mutation and flow cytometry were utilized to investigate the mechanisms of HMGCS2-mediated lipid metabolism in AECIIs.ResultsInjured AECIIs were the primary source of accumulated lipids in response to Bleomycin stimulation. LysoPCs released by injured AECIIs could activate lung fibroblasts, thus promoting the progression of pulmonary fibrosis. Mechanistically, HMGCS2 was decreased explicitly in AECIIs and ectopic expression of HMGCS2 in AECIIs using the AAV system significantly alleviated experimental mouse lung fibrosis progression via modulating lipid degradation in AECIIs through promoting CPT1A and CPT2 expression by interacting with PPARα.ConclusionsThese data unveiled a novel etiological mechanism of HMGCS2-mediated AECII lipid metabolism in the genesis and development of pulmonary fibrosis and provided a novel target for clinical intervention.

Repair and regeneration of the alveolar epithelium in lung injury.

Considerable progress has been made in understanding the function of alveolar epithelial cells in a quiescent state and regeneration mechanism after lung injury. Lung injury occurs commonly from severe viral and bacterial infections, inhalation lung injury, and indirect injury sepsis. A series of pathological mechanisms caused by excessive injury, such as apoptosis, autophagy, senescence, and ferroptosis, have been studied. Recovery from lung injury requires the integrity of the alveolar epithelial cell barrier and the realization of gas exchange function. Regeneration mechanisms include the participation of epithelial progenitor cells and various niche cells involving several signaling pathways and proteins. While alveoli are damaged, alveolar type II (AT2) cells proliferate and differentiate into alveolar type I (AT1) cells to repair the damaged alveolar epithelial layer. Alveolar epithelial cells are surrounded by various cells, such as fibroblasts, endothelial cells, and various immune cells, which affect the proliferation and differentiation of AT2 cells through paracrine during alveolar regeneration. Besides, airway epithelial cells also contribute to the repair and regeneration process of alveolar epithelium. In this review, we mainly discuss the participation of epithelial progenitor cells and various niche cells involving several signaling pathways and transcription factors.

Uncommon Causes of Interlobular Septal Thickening on CT Images and Their Distinguishing Features.

Interlobular septa thickening (ILST) is a common and easily recognized feature on computed tomography (CT) images in many lung disorders. ILST thickening can be smooth (most common), nodular, or irregular. Smooth ILST can be seen in pulmonary edema, pulmonary alveolar proteinosis, and lymphangitic spread of tumors. Nodular ILST can be seen in the lymphangitic spread of tumors, sarcoidosis, and silicosis. Irregular ILST is a finding suggestive of interstitial fibrosis, which is a common finding in fibrotic lung diseases, including sarcoidosis and usual interstitial pneumonia. Pulmonary edema and lymphangitic spread of tumors are the commonly encountered causes of ILST. It is important to narrow down the differential diagnosis as much as possible by assessing the appearance and distribution of ILST, as well as other pulmonary and extrapulmonary findings. This review will focus on the CT characterization of the secondary pulmonary lobule and ILST. Various uncommon causes of ILST will be discussed, including infections, interstitial pneumonia, depositional/infiltrative conditions, inhalational disorders, malignancies, congenital/inherited conditions, and iatrogenic causes. Awareness of the imaging appearance and various causes of ILST allows for a systematic approach, which is important for a timely diagnosis. This study highlights the importance of a structured approach to CT scan analysis that considers ILST characteristics, associated findings, and differential diagnostic considerations to facilitate accurate diagnoses.

The glycosaminoglycan-binding chemokine fragment CXCL9(74-103) reduces inflammation and tissue damage in mouse models of coronavirus infection.

Pulmonary diseases represent a significant burden to patients and the healthcare system and are one of the leading causes of mortality worldwide. Particularly, the COVID-19 pandemic has had a profound global impact, affecting public health, economies, and daily life. While the peak of the crisis has subsided, the global number of reported COVID-19 cases remains significantly high, according to medical agencies around the world. Furthermore, despite the success of vaccines in reducing the number of deaths caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there remains a gap in the treatment of the disease, especially in addressing uncontrolled inflammation. The massive recruitment of leukocytes to lung tissue and alveoli is a hallmark factor in COVID-19, being essential for effectively responding to the pulmonary insult but also linked to inflammation and lung damage. In this context, mice models are a crucial tool, offering valuable insights into both the pathogenesis of the disease and potential therapeutic approaches. Here, we investigated the anti-inflammatory effect of the glycosaminoglycan (GAG)-binding chemokine fragment CXCL9(74-103), a molecule that potentially decreases neutrophil transmigration by competing with chemokines for GAG-binding sites, in two models of pneumonia caused by coronavirus infection. In a murine model of betacoronavirus MHV-3 infection, the treatment with CXCL9(74-103) decreased the accumulation of total leukocytes, mainly neutrophils, to the alveolar space and improved several parameters of lung dysfunction 3 days after infection. Additionally, this treatment also reduced the lung damage. In the SARS-CoV-2 model in K18-hACE2-mice, CXCL9(74-103) significantly improved the clinical manifestations of the disease, reducing pulmonary damage and decreasing viral titers in the lungs. These findings indicate that CXCL9(74-103) resulted in highly favorable outcomes in controlling pneumonia caused by coronavirus, as it effectively diminishes the clinical consequences of the infections and reduces both local and systemic inflammation.

Drug-related pneumonitis caused by amikacin liposome inhalation suspension: One pathologically proven case and single-center experience

Amikacin liposome inhalation suspension (ALIS) is known to cause drug-related pneumonitis, which has been described as “hypersensitivity pneumonitis (HP)”. However, its clinical and pathological characteristics have never been reported. We retrospectively evaluated 18 patients treated with ALIS. Three (16.7%) patients developed HP-pattern pneumonitis on high-resolution computed tomography. Serum eosinophil counts were elevated up to above 1000/μL in these three patients, which decreased with ALIS discontinuation only. Of note, the specimen obtained by transbronchial lung cryobiopsy in one patient revealed a mild degree of lymphocyte and eosinophil infiltration. Rather, the findings of acute lung injury such as an edematous thickening of the alveolar walls, and an accumulation of foamy degenerative macrophages in the alveolar lumina was prominent. A pulmonary alveolar proteinosis reaction was also observed. HP-pattern pneumonitis due to ALIS may pathologically correspond to acute lung injury and a pulmonary alveolar proteinosis reaction despite increasing serum eosinophil counts.

Nasal septum-derived chondroprogenitor cells control mandibular condylar resorption consequent to orthognathic surgery: a clinical trial.

Condylar resorption is an aggressive and disability form of temporomandibular joint (TMJ) degenerative disease, usually non-respondent to conservative or minimally invasive therapies and often leading to surgical intervention and prostheses implantation. This condition is also one of the most dreaded postoperative complications of orthognathic surgery, with severe cartilage erosion and loss of subchondral bone volume and mineral density, associated with a painful or not inflammatory processes. Because regenerative medicine has emerged as an alternative for orthopedic cases with advanced degenerative joint disease, we conducted a phase I/IIa clinical trial (U1111-1194-6997) to evaluate the safety and efficacy of autologous nasal septal chondroprogenitor cells. Ten participants underwent biopsy of the nasal septum cartilage during their orthognathic surgery. The harvested cells were cultured in vitro and analyzed for viability, presence of phenotype markers for mesenchymal stem and/or chondroprogenitor cells, and the potential to differentiate into chondrocytes, adipocytes, and osteoblasts. After the intra-articular injection of the cell therapy, clinical follow-up was performed using the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and computed tomography (CT) images. No serious adverse events related to the cell therapy injection were observed during the 12-month follow-up period. It was found that autologous chondroprogenitors reduced arthralgia, promoted stabilization of mandibular function and condylar volume, and regeneration of condylar tissues. This study demonstrates that chondroprogenitor cells from the nasal septum may be a promise strategy for the treatment of temporomandibular degenerative joint disease that do not respond to other conservative therapies.

Effect of SHP-1 knockout in airway epithelial cells on emphysema phenotype in chronic obstructive pulmonary disease in mice

Objective: To construct and characterize conditional Src homology region 2 protein tyrosine phosphatase 1 (SHP-1) knockout mice in airway epithelial cells and to observe the effect of defective SHP-1 expression in airway epithelial cells on the emphysema phenotype in chronic obstructive pulmonary disease (COPD). Methods: To detect the expression of SHP-1 in the airway epithelium of COPD patients. CRISPR/Cas9 technology was used to construct SHP-1flox/flox transgenic mice, which were mated with airway epithelial Clara protein 10-cyclase recombinase and estrogen receptor fusion transgenic mice (CC10-CreER+/+), and after intraperitoneal injection of tamoxifen, airway epithelial SHP-1 knockout mice were obtained (SHP-1flox/floxCC10-CreER+/-, SHP-1Δ/Δ). Mouse tail and lung tissue DNA was extracted and PCR amplified to discriminate the genotype of the mice; the knockout effect of SHP-1 gene in airway epithelial cells was verified by qRT-PCR, Western blotting, and immunofluorescence. In addition, an emphysema mouse model was constructed using elastase to assess the severity of emphysema in each group of mice. Results: Airway epithelial SHP-1 was significantly downregulated in COPD patients. Genotyping confirmed that SHP-1Δ/Δ mice expressed CC10-CreER and SHP-1-flox. After tamoxifen induction, we demonstrated the absence of SHP-1 protein expression in airway epithelial cells of SHP-1Δ/Δ mice at the DNA, RNA, and protein levels, indicating that airway epithelial cell-specific SHP-1 knockout mice had been successfully constructed. In the emphysema animal model, SHP-1Δ/Δ mice had a more severe emphysema phenotype compared with the control group, which was manifested by disorganization of alveolar structure in lung tissue and rupture and fusion of alveolar walls to form pulmonary alveoli. Conclusions: The present study successfully established and characterized the SHP-1 knockout mouse model of airway epithelial cells, which provides a new experimental tool for the in-depth elucidation of the role of SHP-1 in the emphysema process of COPD and its mechanism.

TL1A is an epithelial alarmin that cooperates with IL-33 for initiation of allergic airway inflammation.

Epithelium-derived cytokines or alarmins, such as interleukin-33 (IL-33) and thymic stromal lymphopoietin (TSLP), are major players in type 2 immunity and asthma. Here, we demonstrate that TNF-like ligand 1A (TL1A) is an epithelial alarmin, constitutively expressed in alveolar epithelium at steady state in both mice and humans, which cooperates with IL-33 for early induction of IL-9high ILC2s during the initiation of allergic airway inflammation. Upon synergistic activation by IL-33 and TL1A, lung ILC2s acquire a transient IL-9highGATA3low "ILC9" phenotype and produce prodigious amounts of IL-9. A combination of large-scale proteomic analyses, lung intravital microscopy, and adoptive transfer of ILC9 cells revealed that high IL-9 expression distinguishes a multicytokine-producing state-of-activated ILC2s with an increased capacity to initiate IL-5-dependent allergic airway inflammation. Similar to IL-33 and TSLP, TL1A is expressed in airway basal cells in healthy and asthmatic human lungs. Together, these results indicate that TL1A is an epithelium-derived cytokine and an important cofactor of IL-33 in the airways.

Co-Delivery of Astaxanthin and siTGF-β1 via Ionizable Liposome Nanoparticles for Improved Idiopathic Pulmonary Fibrosis Therapy.

Alleviating the injury of type II alveolar epithelial cells (AEC 2s) and inhibiting the activation and differentiation of fibroblasts are significant for improving the therapeutic effect of idiopathic pulmonary fibrosis (IPF). To this aim, ionizable liposome nanoparticles (ASNPs) coloaded with antioxidant drug astaxanthin (AST) and small interfering RNA targeting transforming growth factor β1 (siTGF-β1) were developed for enhanced IPF therapy. ASNPs showed high loading and intracellular delivery efficiency for AST and siTGF-β1. After the injection of ASNPs in an IPF mice model, the loaded AST largely scavenged reactive oxygen species (ROS) in the diseased lung to reduce AEC2 apoptosis, thereby ensuring the integrity of the alveolar epithelium. Meanwhile, siTGF-β1, delivered by ASNPs, significantly silenced the expression of TGF-β1 in fibroblasts, inhibiting the differentiation of fibroblasts into myofibroblasts as well as reducing the excessive deposition of extracellular matrix (ECM). The combined use of the two drugs exhibited an excellent synergistic antifibrotic effect and was conducive to minimizing alveolar epithelial damage. This work provides a codelivery strategy of AST and siTGF-β1, which shows great promise for the treatment of IPF by simultaneously reducing alveolar epithelial damage and inhibiting fibroblast activation.

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.

Clinical case of pulmonary alveolar proteinosis in a newborn

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by the accumulation of protein-lipid complexes in the alveoli due to impaired utilization of surfactant by alveolar macrophages; it is most often idiopathic and occurs in healthy men and women aged 30–50 years. The congenital form of PAP is extremely rare, its diagnosis is complicated by the fact that it is impossible to conduct functional lung tests in newborns, and lung biopsy is used extremely rarely. Against this background, data obtained by computed tomography (CT) of the lungs of newborns are of particular importance. The article presents a clinical case of treatment of a newborn with respiratory failure (RF) and signs of pulmonary hypertension, who was admitted to the neonatal intensive care unit of the Children’s City Multidisciplinary Clinical Specialized Center for High Medical Technologies at the age of the first day of life. The article reflects the role of computed tomography in diagnosing the causes of respiratory failure in newborns, as well as the importance of anamnesis and a thorough clinical examination of patients. The presented clinical case demonstrates the need for a multidisciplinary approach to the diagnosis of newborns with pulmonary alveolar proteinosis.