Pulmonary Epithelial Cells Research Articles

CDK14 regulates the development and repair of lung

Cyclin-dependent kinases (CDK) 14 regulates cell cycle, tumor expansion by influencing the downstream targets of the canonical Wnt signaling pathway. However, the function of CDK14 during organ development and regeneration has not been investigated in genetically-modified animals. Here, we found that genetic ablation of Cdk14 influenced pulmonary vascular endothelial cells and alveolar epithelial cells during mice embryonic development as well as repair of lung after bleomycin or lipopolysaccharide induced injury. Genetic knockout of Cdk14 and the CDK14 covalent inhibitor FMF-04-159-2 resulted in reduction of pulmonary vessel covered area and epithelial cell number, exhibiting increased mortality and more severe lung damage after injury. Mechanistically, Cdk14 ablation inhibited the proliferation of epithelial and vascular endothelial cells, inducing cell cycle arrest at the G2/M phase. Through RNA-seq analysis of both endothelial and epithelial cells, we found that knockdown of Cdk14 controls the expression of signal transducers and activator of transcription 1 (STAT1) as well as associated genes in interferon signaling. Disruption of Cdk14 interferes with IFN-γ induced lung repair in vivo, suggesting potential crosstalk of CDK14 signaling and IFN-γ pathway. Our work highlights the importance of Cdk14 in lung development and regenerative repair through an uncharacterized CDK14- IFN-γ signaling axis.

Evaluation of Biological Activity of a Lepidium meyenii (Maca) Polysaccharide‐Zinc Complex

ABSTRACTZinc, an important metal element in the human body, fulfills multiple biological roles, such as influence on cell division and differentiation. In this paper, a Maca polysaccharide‐zinc (MPS‐Zn) complex was prepared by water extraction and alcohol precipitation process. A granular MPS‐Zn complex with 0.2360 μg/mg Zn was obtained at 60°C and pH = 3.0 for 60 min. The antioxidant activities of this MPS‐Zn complex were evaluated by the free radical scavenging activity toward DPPH and ABTS. The rate of ABTS free radical scavenging of 4.0 mg/mL MPS‐Zn complex is equal to that of control group (vitamin C). The abilities of this complex against three cancer cell lines including breast cancer MCF‐7, colon cancer SW480, and liver cancer SMMC‐7721 were used to evaluate its antiproliferative activity by MTS assay. The results demonstrate that this complex has an inhibitory effect on the above cancer cell lines. Especially, the inhibitory effect of it on colon cancer SW480 is more effective than that of cisplatin. The toxicity of this complex on human normal pulmonary epithelial cell BEAS‐2B is lower than that of taxol and cisplatin. This complex has the potential use as the zinc‐containing nutritional food and/or anticancer drug.

SIRT5-mediated HOXA5 desuccinylation inhibits ferroptosis to alleviate sepsis induced-lung injury.

Acute lung injury (ALI) is a common and severe complication of sepsis with a high mortality rate. Ferroptosis, an iron-dependent form of cell death, contributes to lung injury. Homeobox A5 (HOXA5) is involved in the regulation of septic acute kidney damage; however, its function on ferroptosis in septic ALI remains unclear. An in vitro model of septic lung injury was established in the pulmonary epithelial cell line (MLE-12) via lipopolysaccharide (LPS) stimulation. Cell viability, ferrous iron (Fe2+) level, and cellular lipid reactive oxygen species (ROS) were determined with Cell Counting Kit-8 assay, iron assay kit, and BODIPY™ 665/676 molecular probe, respectively. HOXA5, ferroptosis suppressor protein 1 (FSP1), sirtuin 5 (SIRT5), and glutathione peroxidase 4 (GPX4) expressions were measured using western blotting and Real-Time Quantitative Polymerase Chain Reaction (RT-qPCR. Chromatin immunoprecipitation and luciferase reporter assays were performed to validate HOXA5 binding to the FSP1/GPX4 promoter, and regulation of SIRT5 on HOXA5 desuccinylation was confirmed through co-immunoprecipitation. LPS stimulation induced ferroptosis (reduced cell viability, elevated Fe2+ and lipid ROS levels, and decreased GPX4 levels) and downregulated FSP1 and HOXA5 protein levels. HOXA5 overexpression neutralized LPS-induced ferroptosis. Moreover, LPS exposure inhibited HOXA5 binding to the FSP1 promoter, which was counteracted via HOXA5 overexpression. Furthermore, SIRT5 overexpression suppressed LPS-induced ferroptosis. In LPS-challenged MLE-12 cells, SIRT5-mediated HOXA5 desuccinylation was reduced. HOXA5 depletion neutralized the suppressive role of SIRT5 overexpression in LPS-induced ferroptosis. SIRT5-mediated HOXA5 desuccinylation inhibited LPS-induced ferroptosis by upregulating FSP1, which may offer a prospective therapeutic strategy for septic lung injury.

Synthesis and In Vitro Anticancer Activity of Pyrrolidone Derivatives Bearing 3,4,5-Trimethoxyphenyl Moiety as a Promising Anticancer Scaffold

A series of 5-oxo-1-(3,4,5-trimethoxyphenyl)pyrrolidine-3-carboxylic acid derivatives–hydrazones, N-ethylhydrazones, pyrrole, pyrazole, oxadiazole, and triazole were synthesized and evaluated for their anticancer activity using human A549 pulmonary epithelial cells (ATCC CCl-185). The in vitro viability inhibitory effects of the compounds were assessed using the MTT assay. The characterization of the anticancer activity of the synthesized compounds showed that the incorporation of 1,3,4-oxadiazolethione and 4-aminotriazolethione rings into the molecular structures obviously enhances the anticancer activity against human A549 lung epithelial cells, reducing their viability to 28.0% and 29.6%, respectively. The anticancer activity of these azole derivatives was significantly higher than that of cytarabine. Further studies are needed to better optimize 5-oxo-1-(3,4,5-trimethoxyphenyl)pyrrolidine-3-carboxylic acid derivatives and enhance their in vitro anticancer activity.

Meconium Influences Pulmonary Short-Chain Fatty Acid Concentration in Porcine Meconium Aspiration Model

Introduction: The factors influencing meconium aspiration syndrome (MAS) severity remain poorly understood. In a piglet model of MAS, we hypothesized the respiratory microbiome would reflect the bacterial signature of meconium with short-chain fatty acid (SCFA) accumulation as a byproduct of bacterial fermentation. Methods: Cesarean section at approximately 115-day term was performed on two sows. Male (9) and female (3) piglets were delivered, instrumented, anesthetized, and randomized into a Control (n = 6) or MAS group (n = 6). MAS received a meconium slurry (3 mL/kg) aspiration injury. Experimental animals were monitored continuously, ventilated, and resuscitated for 24 h. BALF was collected for 16S microbiome sequencing and SCFA analysis by gas chromatography. Effects of SCFAs on A549 alveolar pulmonary epithelial in vitro cell viability and inflammation were assessed. Results: The MAS group had significantly higher fluid and vasopressor requirements than the Control group (p < 0.05) though both groups developed lung injury. The meconium microbiome demonstrated a difference in genus proportions as compared with the BALF of the Control and MAS groups. The MAS group had a relative increase in propionic acid-forming bacteria and higher BALF concentrations of propionic acid (0.6 ± 0.2 mmol/kg) than the Control group (0.2 ± 0.2 mmol/kg; p > 0.05). Propionic acid was associated with decreased pulmonary epithelial cell viability and an upregulated pro-inflammatory response. Conclusions: Meconium may host a microbiome with byproducts that interact with the pulmonary epithelium and influence lung injury severity in MAS.

Targeting Immune Cells.

The respiratory tract with its vast surface area and very thin air-blood tissue barrier presents an extremely large interface for potential interaction with xenobiotics such as inhaled pathogens or medicaments. To protect its large and vulnerable surface, the lung is populated with several different types of immune cells. Pulmonary epithelial cells, macrophages and dendritic cells are key players in shaping the innate and adaptive immune response. Due to their localization, they represent a frontline of cell populations that are among the first to come in contact with inhaled xenobiotics. Furthermore, depending on the lung compartment they populate, these cells show a large variety in morphology, phenotype, and function. These unique characteristics make those cell populations ideal targets for specific immunomodulators that are designed for inhalation. Depending on cell population or lung compartment targeting, a specific immune response may be triggered or modulated. The purpose of a potent carrier for pulmonary immunomodulation is, first, to efficiently target a specific immunocompetent cell and, second, to affect its role in generating an immune response. Immunomodulation may occur at different levels of immune cell-antigen interaction, i.e. antigen uptake, trafficking, processing and presentation. Inhalation of nanosized carriers for drugs or vaccines shows great potential for both prophylactic and therapeutic approaches in order to modulate immune responses locally or systemically, due to the specific deposition and targeting properties of nanoparticles. Immune responses triggered by nanosized particles may be either immunostimulatory or immunosuppressive and depending on the specific purpose, stimulation or suppression may either be desired or unwanted. Meticulous analysis of immunomodulatory potential, pharmacologic and toxicologic testing of inhalable nanocarriers is required in order to find novel and optimal approaches for prophylaxis and therapy of pulmonary diseases. The design and characterization of such nanoparticles requires well-coordinated interdisciplinary research among engineers, biologists and clinicians.

Exacerbation of pulmonary fibrosis following acute lung injury via activin-A production by recruited alveolar macrophages.

Acute respiratory distress syndrome (ARDS) is a complicated pathological cascade process of excessive pulmonary inflammation and alveolar epithelial cell apoptosis that results in respiratory dysfunction and failure. Some cases of ARDS can result in a more severe state of pulmonary fibrosis, referred to as postinjury lung fibrosis. The mortality and incidence rate of ARDS are high, particularly when it leads to continuing alveolar and interstitial fibrosis, which requires urgent treatment and appropriate management. The lipopolysaccharide (LPS)-induced acute lung injury (ALI) mouse model has been widely implemented for studying ARDS in humans. In our study, we found alterations in the alveolar macrophage (AM) profile in such a mouse model. Specifically, activin-A produced by dominantly recruited AMs (recAMs) was noted to be implicated in the process of post-injury lung fibrosis. The ALI animal model in C57BL/6 mice was established via 3.5 mg/kg of LPS intratracheal administration. Single-cell RNA (scRNA) sequencing was used for detailed classification and functional characterization of lung macrophages. Through in vivo experiments, we evaluated the role that activin-A plays in post-injury lung fibrosis in an ALI mouse model using enzyme-linked immunosorbent assay (ELISA), histological staining methods, and immunofluorescence. Through in vitro experiments, we analyzed the effect of activin-A on murine lung epithelial 12 (MLE-12) cells and bone marrow-derived macrophages (BMDMs) using Western blotting (WB), quantitative real-time polymerase chain reaction, RNA sequencing, and immunofluorescence. Our findings revealed that recAMs replaced tissue-resident alveolar macrophages (TRAMs) as the dominant macrophage population in the setting of ALI. The results of Gene Ontology (GO) analysis suggested that activin-A was associated with wound healing and suppressor of mothers against decapentaplegic (SMAD) protein signaling pathways. Immunofluorescence results revealed that the receptor of activin-A mainly localized to alveolar epithelial cells and macrophages. Subsequently, activin-A was specifically found to drive MLE-12 cells to mesenchymal cell transformation via the transforming growth factor-β (TGF-β)/SMAD signaling. Moreover, the results of transcriptome analysis and WB confirmed that activin-A could enhance the concerted activity of Hippo and TGF-β/SMAD pathways in BMDMs, leading to an increased expression of profibrotic mediator. Moreover, yes-associated protein (YAP) and transcriptional coactivated with PDZ-binding motif (TAZ) proteins were found to drive BMDM activin-A expression, which could generate a positive feedback mechanism that perpetuates fibrosis. Our findings revealed that activin-A is involved in the pathological mechanisms in post-injury lung fibrosis by promoting epithelial-mesenchymal transition (EMT) and the formation of an underlying profibrotic positive feedback loop in recAMs. Activin-A is thus a potential therapeutic target for developing ALI and ALI-associated pulmonary fibrosis therapeutics.

Lung contusion complicated by pneumonia worsens lung injury via the inflammatory effect of alveolar small extracellular vesicles on macrophages and epithelial cells.

Lung contusion (LC) complicated by pneumonia is associated with a higher risk of acute lung injury (ALI) mediated by activation of immune cells and injury to the lung epithelium. Small extracellular vesicles (sEVs) are essential mediators of cellular crosstalk; however, their role in the development of postinjury ALI remains unclear. We hypothesized that LC complicated by pneumonia increases the pro-inflammatory effect of alveolar sEVs on macrophages and the cytotoxicity of alveolar sEVs to pulmonary epithelial cells, worsening the severity of ALI. Studies in C57BL/6 mice were designed with four groups: sham, LC, Pneumonia (Pneu), and LC + Pneu. Lung contusion was induced by a cortical controlled impactor, while pneumonia was conducted by intratracheal injection of 10 5 cfu Pseudomonas aeruginosa . Bronchoalveolar lavage fluid (BAL) was harvested 24 hours postinfection, and sEVs were purified by centrifugation and size exclusion chromatography. To evaluate the effect of alveolar sEV on cells, sEVs from each group were cocultured with macrophages (RAW 264.7) to assess cytokine release and lung epithelial cells (MLE 12) to assess epithelial cytotoxicity. The LC + Pneu group severely injured lungs histologically and increased the susceptibility to the bacteria. The LC + Pneu group showed higher concentrations of proteins, macrophage inflammatory protein 1-alpha (MIP1α), and intercellular adhesion molecule 1 (ICAM-1) in BAL. MIP1α and ICAM-1 expression in the macrophages increased after incubation with sEVs from the LC + Pneu group. Moreover, the sEVs demonstrated higher cytotoxicity to epithelial cells and increased apoptosis in epithelial cells after incubation with sEVs from the LC + Pneu group. Lung contusion complicated by pneumonia increased the pro-inflammatory effect of alveolar sEVs on macrophages and the cytotoxicity of alveolar sEVs to pulmonary epithelial cells, worsening the severity of ALI. These results demonstrate the potential importance of alveolar sEVs in lung inflammation following a bacterial infection after trauma.

Emerging roles of mechanosensitive ion channels in ventilator induced lung injury: a systematic review.

The pathogenetic mechanisms of ventilator-induced lung injury (VILI) still need to be elucidated. The mechanical forces during mechanical ventilation are continually sensed and transmitted by mechanosensitive ion channels (MSICs) in pulmonary endothelial, epithelial, and immune cells. In recent years, MSICs have been shown to be involved in VILI. A systematic search across PubMed, the Cochrane Library, Web of Science, and ScienceDirect was performed from inception to March 2024, and the review was conducted in accordance with PRISMA guidelines. The potential eligible studies were evaluated by two authors independently. Study characteristics, quality assessment, and potential mechanisms were analyzed. We included 23 eligible studies, most of which were performed with murine animals in vivo. At the in vitro level, 52% and 48% of the experiments were conducted with human or animal cells, respectively. No clinical studies were found. The most reported MSICs include Piezo channels, transient receptor potential channels, potassium channels, and stretch-activated sodium channels. Piezo1 has been the most concerned channel in the recent five years. This study found that signal pathways, such as RhoA/ROCK1, could be enhanced by cyclic stretch-activated MSICs, which contribute to VILI through dysregulated inflammation and immune responses mediated by ion transport. The review indicates the emerging role of MSICs in the pathogenesis of VILI, especially as a signal-transmitting link between mechanical stretch and pathogenesis such as inflammation, disruption of cell junctions, and edema formation. Mechanical stretch stimulates MSICs to increase transcellular ion exchange and subsequently generates VILI through inflammation and other pathogeneses mediated by MSICs signal-transmitting pathways. These findings make it possible to identify potential therapeutic targets for the prevention of lung injury through further exploration and more studies. https://inplasy.com/inplasy-2024-10-0115/, identifier INPLASY2024100115.

Inhaled exogenous thymosin beta 4 suppresses bleomycin-induced pulmonary fibrosis in mice via TGF-β1 signalling pathway.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and fibrotic interstitial lung disease. The two drugs indicated for IPF have limited efficacy and there is an urgent need to develop new drugs. Thymosin β4 (Tβ4) is a natural endogenous repair factor whose antifibrotic effects have been reported. This study aimed to evaluate the effect of exogenous recombinant human thymosin beta 4 (rhTβ4) on pulmonary fibrosis. Pulmonary fibrosis was induced in mice with bleomycin, and rhTβ4 was administrated by nebulization following three strategies: early dosing, mid-term dosing, and late dosing. The rhTβ4 efficacy was assessed by hydroxyproline, lung function, and lung histopathology. In vitro, the effects of rhTβ4 on fibroblast and lung epithelial cell phenotypes, as well as the TGF-β1 pathway, were evaluated. Aerosol administration of rhTβ4 could alleviate bleomycin-induced pulmonary fibrosis in mice at different stages of fibrosis. Studies conducted in vitro suggested that rhTβ4 could suppress lung fibroblasts from proliferating, migrating, and activation via regulating the TGF-β1 signalling pathway. In vitro, rhTβ4 also inhibited the epithelial-mesenchymal transition-like process of pulmonary epithelial cells. This study suggests that nebulized rhTβ4 is a potential treatment for IPF.

Regulatory mechanism of TRIM21 in sepsis-induced acute lung injury by promoting IRF1 ubiquitination.

Sepsis-induced acute lung injury (ALI) is characterized by inflammatory damage to pulmonary endothelial and epithelial cells. The aim of this study is to probe the significance and mechanism of tripartite motif-containing protein 21 (TRIM21) in sepsis-induced ALI. The sepsis-induced ALI mouse model was established by cecum ligation and puncture. The mice were infected with lentivirus and treated with proteasome inhibitor MG132. The lung respiratory damage, levels of interleukin-6 (IL-6), tumour necrosis factor α (TNF-α), IL-10 and pathological changes were observed. The expression levels of TRIM21, interferon regulatory factors 1 (IRF1) and triggering receptor expressed on myeloid cells 2 (TREM2) were measured and their interactions were analysed. The ubiquitination level of IRF1 was detected. TRIM21 and TREM2 were downregulated and IRF1 was upregulated in sepsis-induced ALI mice. TRIM21 overexpression eased inflammation and lung injury. TRIM21 promoted IRF1 degradation via ubiquitination modification. IRF1 bonded to the TREM2 promoter to inhibit its transcription. Overexpression of IRF1 or silencing TREM2 reversed the improvement of TRIM21 overexpression on lung injury in mice. In conclusion, TRIM21 reduced IRF1 expression by ubiquitination to improve TREM2 expression and ameliorate sepsis-induced ALI.

Epidermal growth factor receptor signaling governs the host inflammatory response to invasive aspergillosis.

The epidermal growth factor receptor (EGFR) has been identified as an epithelial cell receptor for Mucorales fungi and Candida albicans. Blocking EGFR with small molecule inhibitors reduces disease severity in mouse models of mucormycosis and oropharyngeal candidiasis. In contrast, cases of invasive aspergillosis have been reported in cancer patients who were treated with EGFR inhibitors, suggesting that EGFR signaling may play a protective role in the host defense against this infection. Here, we analyzed transcriptomic data from the lungs of mice with invasive aspergillosis and found evidence that Aspergillus fumigatus infection activates multiple genes that are predicted to function in the EGFR signaling pathway. We also found that A. fumigatus infection activates EGFR in both a human small-airway epithelial (HSAE) cell line and in the lungs of immunosuppressed mice. EGFR signaling in HSAE cells is required for maximal endocytosis of A. fumigatus and for fungal-induced proinflammatory cytokine and chemokine production. In a corticosteroid immunosuppressed mouse model of invasive pulmonary aspergillosis, inhibition of EGFR with gefitinib decreased whole-lung cytokine and chemokine levels and reduced accumulation of phagocytes in the lung, leading to a decrease in fungal killing, an increase in pulmonary fungal burden, and accelerated mortality. Thus, EGFR signaling is required for pulmonary epithelial cells to orchestrate the host innate immune defense against invasive aspergillosis in immunosuppressed hosts.IMPORTANCEWhen A. fumigatus infects the lungs, it invades epithelial cells that line the airways. During this process, the fungus interacts with epithelial cell receptors. This interaction stimulates epithelial cells to endocytose the fungus. It also induces these cells to secrete proinflammatory cytokines and chemokines that recruit phagocytes to the site of infection where they can kill the fungus. Here, we show that in small-airway epithelial cells, the EGFR acts as a sensor for A. fumigatus that triggers the production of chemokines in response to fungal infection. In corticosteroid-immunosuppressed mice, blocking EGFR with the kinase inhibitor gefitinib reduces chemokine production in the lungs. This leads to decreased accumulation of neutrophils and dendritic cells in the lungs, reduced A. fumigatus killing, and increased mortality. These results provide a potential explanation as to why some cancer patients who are treated with EGFR inhibitors develop invasive aspergillosis.

Vaping/e-cigarette-induced pulmonary extracellular vesicles contribute to exacerbated cardiomyocyte impairment through the translocation of ERK5

AimsThe impact of e-cigarettes/vaping on cardiac function remains contradictory owing to insufficient direct evidence of interorgan communication. Extracellular vesicles (EVs) have protective or detrimental effects depending on pathological conditions, making it crucial to understand their role in lung-cardiac cell interactions mediated by vaping inhalation. Methods and key findingsPulmonary EVs were characterized from animals that underwent 12 weeks of nicotine inhalation (vaping component) (EVsNicotine) or vehicle control (EVsVehicle). EVsNicotine significantly increased in size and abundance compared with EVsVehicle. The direct effect of EVs Nicotine and EVs Vehicle on cardiomyocytes was then assessed in vitro and in vivo. EVs Nicotine led to a decrease in cardiac function as manifested by reduced cardiac contractility and impaired relaxation. EVs Nicotine induced increased levels of cleaved caspase-1 and cleaved caspase-11 in cardiomyocytes, indicating the promotion of pyroptosis. Meanwhile, EVsNicotine stimulated the secretion of fibrotic factors. Further analysis revealed that nicotine inhalation stimulated EVs Nicotine enriched with high levels of ERK5 (EVs Nicotine-ERK5). It was discovered that these EVs derived from pulmonary epithelial cells. Furthermore, inhibiting cardiac ERK5 blunted the EVs Nicotine-induced pyroptosis and fibrotic factor secretion. We further identified GATA4, a pro-pyroptosis transcription factor, as being activated through ERK5-dependent phosphorylation. SignificanceOur research demonstrates that nicotine inhalation exacerbates cardiac injury through the activation of EVs derived from the lungs during e-cigarettes/vaping. Specifically, the EVs containing ERK5 play a crucial role in mediating the detrimental effects on cardiac function. This research provides new insights into the cardiac toxicity of vaping and highlights the role of EVs Nicotine-ERK5 in this process.

Effects of the combination of anti-PcrV antibody and bacteriophage therapy in a mouse model of Pseudomonas aeruginosa pneumonia.

Acute lung injury caused by Pseudomonas aeruginosa is attributed to the translocation of cytotoxin into pulmonary epithelial cells via the P. aeruginosa type III secretion system. This virulence can be blocked with a specific antibody against PcrV in this secretion system. However, because anti-PcrV antibodies do not have bactericidal activity, the treatment of bacteria depends on the phagocytic system of the host. In this study, we investigated the therapeutic effect of combination therapy with an anti-PcrV antibody and bactericidal bacteriophages on acute lung injury and subsequent death in mice compared with a single treatment. After the mice intratracheally received a lethal dose of the cytotoxic P. aeruginosa strain, a second instillation was performed with saline, anti-PcrV IgG, bacteriophages, or a mixture of anti-PcrV and bacteriophages. The survival rates 24 h after infection were as follows: 7.1% in the saline group, 26.7% in the anti-PcrV group, 41.2% in the phage group, and 66.7% in the anti-PcrV + phage group (P < 0.001 vs saline-treated group). The activity of surviving mice in the anti-PcrV + phage group was significantly greater than that in the saline group. The lung weight in the anti-PcrV + phage group was significantly lower than that in the anti-PcrV group. In conclusion, combination therapy with an anti-PcrV antibody and a bacteriophage reduces acute lung injury and suggests improved survival compared with each treatment alone. This combination therapy, which does not rely on conventional antibiotics, could constitute a new strategy for treating multidrug-resistant P. aeruginosa infections.IMPORTANCECombination therapy with either bacteriophages alone or in combination with anti-PcrV antibodies in a mouse model of Pseudomonas aeruginosa pneumonia may reduce the acute lung injury and improve survival. This combination therapy, which does not rely on conventional antibiotics, may be a new strategy to treat multidrug-resistant Pseudomonas aeruginosa infections.

The Role of Retinoic-Acid-Related Orphan Receptor (RORs) in Cellular Homeostasis.

Retinoic-acid-related orphan receptors (RORs) are transcription factors belonging to the nuclear receptor subfamily consisting of RORα, RORβ, and RORγ. By binding to the ROR response elements (ROREs) on target gene promoters, RORs regulate a wide variety of cellular processes, including autophagy, mitophagy, oxidative stress, and inflammation. The regulatory roles of RORs are observed in cardiac cells, hepatocytes, pulmonary epithelial cells, renal cells, immune cells, and cancer cells. A growing body of clinical and experimental evidence suggests that ROR expression levels are markedly reduced under different pathological and stress conditions, suggesting that RORs may play a critical role in the pathogenesis of a variety of disease states, including myocardial infarction, immune disorders, cancer, and metabolic syndrome. Reductions in RORs are also associated with inhibition of autophagy, increased reactive oxygen species (ROS), and increased cell death, underscoring the importance of RORs in the regulation of these processes. Herein, we highlight the relationship between RORs and homeostatic processes that influence cell viability. Understanding how these intricate processes are governed at the cellular level is of high scientific and clinical importance to develop new therapeutic strategies that modulate ROR expression and disease progression.

Formulation and optimization of transferrin-modified genistein nanocrystals: In vitro anti-cancer assessment and pharmacokinetic evaluation

In this research work, nanocrystals (NC) of poorly water-soluble drug genistein (Gen) were formulated to improve its aqueous solubility and bioavailability. Genistein nanocrystals (Gen–NC) were prepared by wet ball milling. The formulation was optimized using Box Behnken Design Expert to evaluate the impact of stabilizer concentration, drug concentration and quantity of zirconium beads (milling media) on NC size, polydispersity and zeta potential. The NCs were surface-decorated with transferrin (Tf) to form Tf modified Gen-NCs (Tf-Gen-NC) for improving cancer cell selectivity and cytotoxicity. The NC formulations were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray power diffraction (XRD) and differential scanning calorimetry (DSC). The particle size distribution of the optimized formulation varied from 200 to 300 nm with poly dispersibility index (PDI) between 0.1 and 0.3. Tf-Gen-NC and Gen-NC released 96 % and 80 % of the drug content in 20 min at 37 °C, respectively, whereas only 18 % were released with the unprocessed drug. In vitro cytotoxicity was tested in pulmonary adenocarcinoma epithelial cells (A549) and fibroblast cell line (L929). The Tf-Gen-NC presented an enhanced anticancer effect. In vivo pharmacokinetic studies in mice after intraperitoneal administration showed that the Cmax of NC formulations were 2.5-fold higher compared to free Gen. The area under the curve from time of administration to 24 h was 2.5 to 3-fold higher when compared with unprocessed drug. This study shows the interest of Gen-NC in the development of new formulations for Gen as an anticancer drug.

Serum Apelin Levels and Correlation with illness Severity in Nonobese Patients with Bronchial Asthma

Abstract Background: Asthma is one of the most common chronic diseases globally. It is characterized by airflow obstruction that varies markedly, regardless of treatment. It is a type of airway inflammation due to bronchial hyperresponsiveness to a wide range of allergens, leading to excessive, usually reversible, airway narrowing. Asthma occurs more frequently in obese people, and it may be linked to pro-inflammatory adipokines. Apelin, a bioactive peptide belonging to the adipokines group, is identified as an endogenous ligand of an orphan G-protein coupled receptor named Apelin receptor (AR or APJ). Apelin is demonstrated in mature adipocytes and is highly expressed in pulmonary tissue, including bronchial and alveolar epithelial cells and small pulmonary blood vessels. Aim: The aim of this study was to evaluate the level of serum apelin in adult nonobese patients diagnosed with bronchial asthma cases and compare with healthy volunteers. We also aimed to correlate serum apelin levels with the severity of bronchial asthma. Materials and Methods: Twenty-two nonobese clinically diagnosed cases of bronchial asthma were included as cases and 66 age, sex, and socio-economic status-matched healthy volunteers as controls. Body mass index of cases and control subjects was calculated by weight (kg) per height (m2). Pulmonary function tests of the cases were done using spirometry. Serum apelin levels were estimated using Abbkine human ELISA-based kit. Statistical analysis was done using Pearson’s correlation test and analysis of variance. Results: We recruited 22 nonobese bronchial asthma cases (mean age = 38.2 ± 10.5 years) and 66 matched controls (mean age = 39.5 ± 12.0 years. Majority of the sample were females (n = 19 cases [86.3%], 54 controls [81.8%]). The mean serum apelin levels in cases and controls were 1355.3 ± 781.0 ng/L and 725.9 ± 375.6 ng/L, respectively; this difference was statistically significant (t = 5.053, df = 86, p = 0.001). The mean serum apelin levels in mild and moderate cases of bronchial asthma were 1121.5 ± 535.9 ng/L and 2150.2 ± 1019.1 ng/L, respectively. This difference was also statistically significant (t = 3.06, df = 20, p = 0.01). Conclusion: Serum apelin levels differ significantly between adult patients with bronchial asthma and population controls. Further, serum apelin levels differed with illness severity. These findings have important implications for disease management.

Fibroblast growth factor 21 attenuates pulmonary ischemia/reperfusion injury via inhibiting endoplasmic reticulum stress-induced ferroptosis though FGFR1/PPARδ signaling pathway

BackgroundAcute lung injury is a critical life-threatening complication of pulmonary and cardiac surgery with a high rate of morbidity and mortality. Fibroblast growth factor 21 (FGF21) has been reported to play an important role in protecting vital organs from damage. This study aims to investigate the potential protective role and mechanism of FGF21 in pulmonary ischemia/reperfusion (I/R)-induced acute lung injury. MethodsA pulmonary epithelial cell line was treated with hypoxia/regeneration (H/R) in vitro and a mouse model of acute lung injury was induced with pulmonary I/R in vivo. Lung injury after pulmonary I/R was compared between FGF21-konckout (KO) mice and wild-type (WT) mice. Recombinant FGF21 was administrated in vivo and in vitro to determine its therapeutic effect. ResultsCirculating levels of FGF21 in mice with pulmonary I/R injury were significantly higher than in those without pulmonary I/R injury. Lung injury was aggravated in FGF21-KO mice compared with WT mice and the administration of FGF21 alleviated lung injury in mouse treated with I/R and pulmonary epithelial cell injury treated with H/R. FGF21 treatment decreased endoplasmic reticulum (ER) stress, Fe2+ and lipid reactive oxygen species (ROS) contents and GPX4 expression and increased PTGS2 levels. Mechanistically, FGF21 upregulated the expression of FGFR1 and PPARδ, ameliorated ER stress and ER stress induced-ferroptosis. Furthermore, FGF21 increased the expression level of PPARδ in pulmonary epithelial cell exposed to H/R, which was inhibited by FGFR1 inhibitor (PD173074). The protective effects of FGF21 were abolished by co-treatment with PPARδ inhibitor (GSK0660), indicating FGF21 attenuated ER stress-induced ferroptosis by dependent on FGFR1/PPARδ signaling pathway. ConclusionOur study reveals that FGF21 protects against pulmonary I/R injury via inhibiting ER stress-induced ferroptosis though FGFR1/PPARδ signaling pathway. Boosting endogenous FGF21 or the administration of recombinant FGF21 could be promising therapeutic strategies for pulmonary IRI.

Differences in cellular and molecular processes in exposure to PM2.5 and O3

Epidemiological and toxicological studies have shown that PM2.5 and O3 could pose significant risks to human health, such as an increased incidence of respiratory and cardiovascular diseases. Usually, the adverse health outcomes induced by PM2.5 and O3 exposure are similar. However, PM2.5 and O3 have distinct physical and chemical properties, with PM2.5 being a solid–liquid mixture and O3 being a strongly oxidizing gaseous pollutant. Therefore, we speculated that there are some differences in biological processes induced by PM2.5 and O3 exposure. In the present study, we investigated the differences induced by PM2.5 and O3 exposure from the perspective of cellular and molecular processes. Firstly, the pulmonary epithelial cells (BEAS-2B) were exposed to different concentrations of PM2.5 or O3 at different durations. Then, we chose experimental models with the concentrations and duration at which the cell survival rate was 50 % after exposure to PM2.5 and O3, which were 100 μg/mL for 24 h for PM2.5, and 200 ppb for 4 h for O3. Our findings indicate that PM2.5 infiltrates cells via endocytosis without causing significant damage to cell membranes, while O3 induces lipid peroxidation at the cell surface. Moreover, the detection of mitochondrial function showed that the content of ATP was significantly reduced after exposure to both PM2.5 and O3. However, we found a significant difference in mtDNA copy number. PM2.5 exposure increased the mtDNA copy number by up-regulating the expression of fission genes (Fis1, Mff, Dnm1). O3 exposure decreased it by up-regulating the expression of fusion gene (Mfn1, Mfn2) and down-regulating the expression of fission gene (Fis1, Dnm1). These results indicate that although both PM2.5 and O3 exposure induced almost exactly similar adverse health outcomes, significant differences do exist in cellular and molecular processes.

Staphylococcus aureus Co-Infection in COVID-19 Patients: Virulence Genes and Their Influence on Respiratory Epithelial Cells in Light of Risk of Severe Secondary Infection.

Pandemics from viral respiratory tract infections in the 20th and early 21st centuries were associated with high mortality, which was not always caused by a primary viral infection. It has been observed that severe course of infection, complications and mortality were often the result of co-infection with other pathogens, especially Staphylococcus aureus. During the COVID-19 pandemic, it was also noticed that patients infected with S. aureus had a significantly higher mortality rate (61.7%) compared to patients infected with SARS-CoV-2 alone. Our previous studies have shown that S. aureus strains isolated from patients with COVID-19 had a different protein profile than the strains in non-COVID-19 patients. Therefore, this study aims to analyze S. aureus strains isolated from COVID-19 patients in terms of their pathogenicity by analyzing their virulence genes, adhesion, cytotoxicity and penetration to the human pulmonary epithelial cell line A549. We have observed that half of the tested S. aureus strains isolated from patients with COVID-19 had a necrotizing effect on the A549 cells. The strains also showed greater variability in terms of their adhesion to the human cells than their non-COVID-19 counterparts.