Evaluation of permeability alteration and epithelial–mesenchymal transition induced by transforming growth factor-β1 in A549, NCI-H441, and Calu-3 cells: Development of an in vitro model of respiratory epithelial cells in idiopathic pulmonary fibrosis

AnxA2-EGFR pro-inflammatory signaling potentiates EMT-induced fibrotic stress and its modulation by short-chain fatty acid butyrate in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a debilitating lung disease characterized by excessive extracellular matrix deposition, leading to irreversible lung scarring. This study explores the underlying molecular mechanisms of IPF and delves into membrane-anchored synergism between EGFR and AnxA2, which amplifies fibrotic stress and plays a pivotal role in promoting pulmonary fibroblast activation and fibrosis. Indeed, these interactions create a synergistic effect that promotes the loss of epithelial traits and the transition to a mesenchymal phenotype, thereby contributing to fibrotic stress and disease progression. In addition, this study also explores the potential of butyrate, a short-chain fatty acid, as a therapeutic agent in reducing fibrotic stress by modulating AnxA2-EGFR signaling. Pre-treatment with butyrate significantly dampens AnxA2-EGFR signaling and Galectin-3 expression, effectively curbing prolonged EGFR phosphorylation. The suppression of upstream signaling leads to a reduction in the angiogenic marker VEGF and a decrease in pro-inflammatory mediators such as TNF-α and IL-6. Collectively, our findings highlight the critical role of EGFR-AnxA2 signaling and Galectin 3 in the pathogenesis of IPF, and highlight butyrate as a potential therapeutic agent for alleviating fibrotic stress.

The interplay between the epithelial permeability barrier, cell migration and mitochondrial metabolism of growth factors and their inhibitors in a human endometrial carcinoma cell line

It is known that there are abnormalities of tight junction functions, cell migration and mitochondrial metabolism in human endometriosis and endometrial carcinoma. In this study, we investigated the effects of growth factors and their inhibitors on the epithelial permeability barrier, cell migration and mitochondrial metabolism in 2D and 2.5D cultures of human endometrioid endometrial carcinoma Sawano cells. We also investigated the changes of bicellular and tricellular tight junction molecules and ciliogenesis induced by these inhibitors. The growth factors TGF-β and EGF affected the epithelial permeability barrier, cell migration and expression of bicellular and tricellular tight junction molecules in 2D and 2.5D cultures of Sawano cells. EW-7197 (a TGF-β receptor inhibitor), AG1478 (an EGFR inhibitor) and SP600125 (a JNK inhibitor) affected the epithelial permeability barrier, cell migration and mitochondrial metabolism and prevented the changes induced by TGF-β and EGF in 2D and 2.5D cultures. EW-7197 and AG1478 induced ciliogenesis in 2.5D cultures. In conclusion, TGF-β and EGF promoted the malignancy of endometrial cancer via interplay among the epithelial permeability barrier, cell migration and mitochondrial metabolism. EW-7197 and AG1478 may be useful as novel therapeutic treatments options for endometrial cancer.

Highly scalable and standardized organ-on-chip platform with TEER for biological barrier modeling

The development of new therapies is hampered by the lack of predictive, and patient-relevant in vitro models. Organ-on-chip (OOC) technologies can potentially recreate physiological features and hold great promise for tissue and disease modeling. However, the non-standardized design of these chips and perfusion control systems has been a barrier to quantitative high-throughput screening (HTS). Here we present a scalable OOC microfluidic platform for applied kinetic in vitro assays (AKITA) that is applicable for high, medium, and low throughput. Its standard 96-well plate and 384-well plate layouts ensure compatibility with existing laboratory workflows and high-throughput data collection and analysis tools. The AKITA plate is optimized for the modeling of vascularized biological barriers, primarily the blood-brain barrier, skin, and lung, with precise flow control on a custom rocker. The integration of trans-epithelial electrical resistance (TEER) sensors allows rapid and repeated monitoring of barrier integrity over long time periods. Together with automated liquid handling and compound permeability testing analyses, we demonstrate the flexibility of the AKITA platform for establishing human-relevant models for preclinical drug and precision medicine's efficacy, toxicity, and permeability under near-physiological conditions.

Optimization of an in vitro method for assessing pulmonary permeability of inhaled drugs using alveolar epithelial cells

INTRODUCTION

Inhalation of drugs for the treatment of pulmonary diseases has been used since a long time. Due to lungs' larger absorptive surface area, delivery of drugs to the lungs is the method of choice for different disorders. Here we present the establishment of a comprehensive permeability model using Type II alveolar epithelial cells and Beclomethasone Dipropionate (BDP) as a model drug delivered by pressurized metered dose inhaler (pMDI).

METHODS

Using Type II alveolar epithelial cells, the method was standardized for parameters viz., cell density, viability, incubation period and membrane integrity. The delivery and deposition of drug were using the pMDI device with a Twin Stage Impinger (TSI) modified to accommodate cell culture insert having monolayer of cells. The analytical method for simultaneous estimation of BDP and Beclomathasone-17-Monopropionate (17-BMP) was validated as per the bioanalytical guidelines. The extent and rate of absorption of BDP was determined by quantifying the amount of drug permeated and the data represented by calculating its apparent permeability.

RESULTS

Type II alveolar epithelial cells cultured at 0.55 × 105 cells/cm2 for 8-12 days under air-liquid interface were optimized for conducting permeability studies. The data obtained for absorptive transport showed a linear increase in the drug permeated against time for both BDP and 17-BMP along with proportional permeability profile.

DISCUSSION

We have developed a robust in vitro model to study absorptive rate of drug transport across alveolar layer. Such models would create potential value during formulation development for comparative studies and selection of clinical candidates.

Prognostic Function and Immunologic Landscape of a Predictive Model Based on Five Senescence-Related Genes in IPF Bronchoalveolar Lavage Fluid

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a type of interstitial lung disease characterized by unknown causes and a poor prognosis. Recent research indicates that age-related mechanisms, such as cellular senescence, may play a role in the development of this condition. However, the relationship between cellular senescence and clinical outcomes in IPF remains uncertain.

METHODS

Data from the GSE70867 database were meticulously analyzed in this study. The research employed differential expression analysis, as well as univariate and multivariate Cox regression analysis, to pinpoint senescence-related genes (SRGs) linked to prognosis and construct a prognostic risk model. The model's clinical relevance and its connection to potential biological processes were systematically assessed in training and testing datasets. Additionally, the expression location of prognosis-related SRGs was identified through immunohistochemical staining, and the correlation between SRGs and immune cell infiltration was deduced using the GSE28221 dataset.

RESULT

The prognostic risk model was constructed based on five SRGs (cellular communication network factor 1, CYR61, stratifin, SFN, megakaryocyte-associated tyrosine kinase, MATK, C-X-C motif chemokine ligand 1, CXCL1, LIM domain, and actin binding 1, LIMA1). Both Kaplan-Meier (KM) curves (p = 0.005) and time-dependent receiver operating characteristic (ROC) analysis affirmed the predictive accuracy of this model in testing datasets, with respective areas under the ROC curve at 1-, 2-, and 3-years being 0.721, 0.802, and 0.739. Furthermore, qRT-RCR analysis and immunohistochemical staining verify the differential expression of SRGs in IPF samples and controls. Moreover, patients in the high-risk group contained higher infiltration levels of neutrophils, eosinophils, and M1 macrophages in BALF, which appeared to be independent indicators of poor prognosis in IPF patients.

CONCLUSION

Our research reveals the effectiveness of the 5 SRGs model in BALF for risk stratification and prognosis prediction in IPF patients, providing new insights into the immune infiltration of IPF progression.

Building respirable powder architectures: utilizing polysaccharides for precise control of particle morphology for enhanced pulmonary drug delivery

INTRODUCTION

Dry powder inhaler (DPI) formulations are gaining attention as universal formulations with applications in a diverse range of drug formulations. The practical application of DPIs to pulmonary drugs requires enhancing their delivery efficiency to the target sites for various treatment modalities. Previous reviews have not explored the relation between particle morphology and delivery to different pulmonary regions. This review introduces new approaches to improve targeted DPI delivery using novel particle design such as supraparticles and metal-organic frameworks based on cyclodextrin.

AREAS COVERED

This review focuses on the design of DPI formulations using polysaccharides, promising excipients not yet approved by regulatory agencies. These excipients can be used to design various particle morphologies by controlling their physicochemical properties and manufacturing methods.

EXPERT OPINION

Challenges associated with DPI formulations include poor access to the lungs and low delivery efficiency to target sites in the lung. The restricted applicability of typical excipients contributes to their limited use. However, new formulations based on polysaccharides are expected to establish a technological foundation for the development of DPIs capable of delivering modalities specific to different lung target sites, thereby enhancing drug delivery.

TGF-β signaling in health, disease, and therapeutics

Transforming growth factor (TGF)-β is a multifunctional cytokine expressed by almost every tissue and cell type. The signal transduction of TGF-β can stimulate diverse cellular responses and is particularly critical to embryonic development, wound healing, tissue homeostasis, and immune homeostasis in health. The dysfunction of TGF-β can play key roles in many diseases, and numerous targeted therapies have been developed to rectify its pathogenic activity. In the past decades, a large number of studies on TGF-β signaling have been carried out, covering a broad spectrum of topics in health, disease, and therapeutics. Thus, a comprehensive overview of TGF-β signaling is required for a general picture of the studies in this field. In this review, we retrace the research history of TGF-β and introduce the molecular mechanisms regarding its biosynthesis, activation, and signal transduction. We also provide deep insights into the functions of TGF-β signaling in physiological conditions as well as in pathological processes. TGF-β-targeting therapies which have brought fresh hope to the treatment of relevant diseases are highlighted. Through the summary of previous knowledge and recent updates, this review aims to provide a systematic understanding of TGF-β signaling and to attract more attention and interest to this research area.

Essential oil from Inula japonica Thunb. And its phenolic constituents ameliorate pulmonary injury and fibrosis in bleomycin-treated mice

ETHNOPHARMACOLOGICAL RELEVANCE

Pulmonary injury and fibrosis can be caused by various factors because of their inflammatory nature, both can lead to serious clinical consequences. Inula japonica Thunb. is used in traditional Chinese medicine for the treatment of lung diseases. However, the effect and mechanism of action of the essential oil of I. japonica (EOI) on pulmonary injury and fibrosis are not well understood.

AIM OF THE STUDY

To investigate the therapeutic effects of EOI on mice with bleomycin (BLM)-induced acute pulmonary injury and chronic fibrosis formation, as well as its potential mechanism.

MATERIALS AND METHODS

A short-term mouse model of pulmonary injury was established by intratracheal injection of BLM to investigate the anti-inflammatory effect of EOI, and a long-term model of pulmonary fibrosis was used to explore the anti-fibrosis effect of EOI. High-dose EOI (200 mg/kg) was administered intragastrically, and low-dose (50 mg/kg) was administered by intratracheal injection. Gas chromatography-mass spectrometry (GC-MS) was used to identify the ingredients in EOI, and high-performance liquid chromatography (HPLC) was performed for the preparation of EOI compounds. Western blot and real-time qPCR were used to verify the effects of EOI and its active composition on inflammation, oxidative stress and fibrosis signaling pathway.

RESULTS

Treatment with EOI significantly reduced the inflammation and oxidative stress by reducing the levels of inflammatory and oxidative cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and malondialdehyde in BLM-treated mice with acute pulmonary injury. EOI treatment could also suppress the formation of fibrous tissue in mice with BLM-induced pulmonary fibrosis through inhibiting TGF-β/Smad and PI3K/Akt pathways. Chromatographic analysis and preparation suggested that fatty acid and phenol derivatives are present in EOI. Based on cellular inflammation and fibrosis models, the phenolic compounds in EOI can represent the anti-inflammatory and anti-fibrotic effects of EOI by regulating pro-inflammatory and pro-fibrotic cytokines such as NO, TNF-α, IL-6, TGF-β1, and α-SMA.

CONCLUSION

EOI ameliorated BLM-induced pulmonary injury and fibrosis in mice by inhibiting the inflammatory response and regulating the redox equilibrium, as well as by mediating TGFβ/Smad and PI3K/Akt, which suggested that EOI has potential to treat pulmonary diseases.

Emerging delivery approaches for targeted pulmonary fibrosis treatment

Pulmonary fibrosis (PF) is a progressive, and life-threatening interstitial lung disease which causes scarring in the lung parenchyma and thereby affects architecture and functioning of lung. It is an irreversible damage to lung functioning which is related to epithelial cell injury, immense accumulation of immune cells and inflammatory cytokines, and irregular recruitment of extracellular matrix. The inflammatory cytokines trigger the differentiation of fibroblasts into activated fibroblasts, also known as myofibroblasts, which further increase the production and deposition of collagen at the injury sites in the lung. Despite the significant morbidity and mortality associated with PF, there is no available treatment that efficiently and effectively treats the disease by reversing their underlying pathologies. In recent years, many therapeutic regimens, for instance, rho kinase inhibitors, Smad signaling pathway inhibitors, p38, BCL-xL/ BCL-2 and JNK pathway inhibitors, have been found to be potent and effective in treating PF, in preclinical stages. However, due to non-selectivity and non-specificity, the therapeutic molecules also result in toxicity mediated severe side effects. Hence, this review demonstrates recent advances on PF pathology, mechanism and targets related to PF, development of various drug delivery systems based on small molecules, RNAs, oligonucleotides, peptides, antibodies, exosomes, and stem cells for the treatment of PF and the progress of various therapeutic treatments in clinical trials to advance PF treatment.

The role of airway mucus and diseased pulmonary epithelium on the absorption of inhaled antibodies

Inhaled antibody therapy for the treatment of respiratory diseases is a promising strategy to maximize pulmonary exposure and reduce side effects associated with parenteral administration. However, the development of inhaled antibodies is often challenging due to a poor understanding of key mechanisms governing antibody absorption and clearance in healthy and diseased pulmonary epithelium. Here, we utilize well established Human Bronchial Epithelial Cell (HBEC) models grown at air-liquid interface to study the absorption process of antibodies and antibody fragments. With these cellular models, we recapitulate the morphology and function of healthy and diseased pulmonary epithelium, and incorporate the mucosal barrier to enable the investigation of both cellular permeability as well as mucodiffusion. We studied the saturation of antibody transport across the HBEC barriers and estimated the impact of disease-like epithelial barriers on antibody paracellular transport. Additionally, we identified a potential role of neonatal Fc receptor (FcRn)-independent and target-mediated transcytosis in the transport of Fragment antigen-binding (Fab) and F(ab)2 antibody fragments. Lastly, our models were able to pinpoint an impaired antibody diffusion across mucus gels. These mechanistic cellular models are promising in vitro tools to inform Physiologically-based Pharmacokinetic (PBPK) computational models for dose prediction toward de-risking the development of inhaled biologics.

Aerosol technology to mimic dry powder inhalation in vitro using pulmonary cell models

Inhaled therapy confers key advantages for the treatment of topical pulmonary diseases and offers potential for systemic delivery of medicines. Dry powder inhalers (DPIs) are generally the preferred devices for pulmonary delivery due to improved stability and satisfactory patient compliance. However, the mechanisms governing drug powder dissolution and availability in the lung and poorly understood. Here, we report a new in vitro system to study epithelial absorption of inhaled dry powders in lung barrier models of the upper and lower airway. The system is based on a CULTEX® RFS (Radial Flow System) cell exposure module joined to a Vilnius aerosol generator and allows the coupling of drug dissolution and permeability assessments. The cellular models recapitulate the barrier morphology and function of healthy and diseased pulmonary epithelium and incorporate the mucosal barrier to enable the investigation of drug powder dissolution in biorelevant conditions. With this system, we found differences in permeability across the airway tree and pinpointed the impact of diseased barriers in paracellular drug transport. Furthermore, we identified a different rank order of permeability for compounds tested in solution or powder form. These results highlight the value of this in vitro drug aerosolization setup for use in research and development of inhaled medicines.

The multiphasic TNF-α-induced compromise of Calu-3 airway epithelial barrier function

Purpose: Airway epithelial barrier leak and the involvement of proinflammatory cytokines play a key role in a variety of diseases. This study evaluates barrier compromise by the inflammatory mediator Tumor Necrosis Factor-α (TNF-α) in the human airway epithelial Calu-3 model. Methods: We examined the effects of TNF-α on barrier function in Calu-3 cell layers using Transepithelial Electrical Resistance (TER) and transepithelial diffusion of radiolabeled probe molecules. Western immunoblot analyses of tight junctional (TJ) proteins in detergent soluble fractions were performed. Results: TNF-α dramatically reduced TER and increased paracellular permeability of both 14C-D-mannitol and the larger 5 kDa probe, 14C-inulin. A time course of the effects shows two separate actions on barrier function. An initial compromise of barrier function occurs 2-4 hours after TNF-α exposure, followed by complete recovery of barrier function by 24 hrs. Beginning 48 hrs. post-exposure, a second more sustained barrier compromise ensues, in which leakiness persists through 144 hrs. There were no changes in TJ proteins observed at 3 hrs. post exposure, but significant increases in claudins-2, -3, -4, and -5, as well as a decrease in occludin were seen at 72 hrs. post TNF-α exposure. Both the 2-4 hr. and the 72 hr. TNF-α induced leaks are shown to be mediated by the ERK signaling pathway. Conclusion: TNF-α induced a multiphasic transepithelial leak in Calu-3 cell layers that was shown to be ERK mediated, as well as involve changes in the TJ complex. The micronutrients, retinoic acid and calcitriol, were effective at reducing this barrier compromise caused by TNF-α. The significance of these results for airway disease and for COVID-19 specifically are discussed.

Downregulation of angulin-1/LSR induces malignancy via upregulation of EGF-dependent claudin-2 and TGF-β-dependent cell metabolism in human lung adenocarcinoma A549 cells

Abnormal expression of bicellular tight junction claudins, including claudin-2 are observed during carcinogenesis in human lung adenocarcinoma. However, little is known about the role of tricellular tight junction molecule angulin-1/lipolysis-stimulated lipoprotein receptor (LSR). In the lung adenocarcinoma tissues examined in the present study, expression of claudin-2 was higher than in normal lung tissues, while angulin-1/LSR was poorly or faintly expressed. We investigated how loss of angulin-1/LSR affects the malignancy of lung adenocarcinoma cell line A549 and normal human lung epithelial (HLE) cells. The EGF receptor tyrosine kinase inhibitor AG1478 prevented the increase of claudin-2 expression induced by EGF in A549 cells. Knockdown of LSR induced expression of claudin-2 at the protein and mRNA levels and AG1478 prevented the upregulation of claudin-2 in A549 cells. Knockdown of LSR induced cell proliferation, cell migration and cell metabolism in A549 cells. Knockdown of claudin-2 inhibited the cell proliferation but did not affect the cell migration or cell metabolism of A549 cells. The TGF-β type I receptor inhibitor EW-7197 prevented the decrease of LSR and claudin-2 induced by TGF-β1 in A549 cells and 2D culture of normal HLE cells. EW-7197 prevented the increase of cell migration and cell metabolism induced by TGF-β1 in A549 cells. EW-7197 prevented the increase of epithelial permeability of FITC-4kD dextran induced by TGF-β1 in 2.5D culture of normal HLE cells. In conclusion, downregulation of angulin-1/LSR induces malignancy via EGF-dependent claudin-2 and TGF-β-dependent cell metabolism in human lung adenocarcinoma.

Novel drug delivery systems and disease models for pulmonary fibrosis

Pulmonary fibrosis (PF) is a serious and progressive lung disease which is possibly life-threatening. It causes lung scarring and affects lung functions including epithelial cell injury, massive recruitment of immune cells and abnormal accumulation of extracellular matrix (ECM). There is currently no cure for PF. Treatment for PF is aimed at slowing the course of the disease and relieving symptoms. Pirfenidone (PFD) and nintedanib (NDNB) are currently the only two FDA-approved oral medicines to slow down the progress of idiopathic pulmonary fibrosis, a specific type of PF. Novel drug delivery systems and therapies have been developed to improve the prognosis of the disease, as well as reduce or minimize the toxicities during drug treatment. The drug delivery routes for these therapies are various including oral, intravenous, nasal, inhalant, intratracheal and transdermal; although this is dependent on specific treatment mechanisms. In addition, researchers have also expanded current animal models that could not fully restore the clinicopathology, and developed a series of in vitro models such as organoids to study the pathogenesis and treatment of PF. This review describes recent advances on pathogenesis exploration, classifies and specifies the progress of drug delivery systems by their delivery routes, as well as an overview on the in vitro and in vivo models for PF research.

In vitro and ex vivo models in inhalation biopharmaceutical research - advances, challenges and future perspectives

Oral inhalation results in pulmonary drug targeting and thereby reduces systemic side effects, making it the preferred means of drug delivery for the treatment of respiratory disorders such as asthma, chronic obstructive pulmonary disease or cystic fibrosis. In addition, the high alveolar surface area, relatively low enzymatic activity and rich blood supply of the distal airspaces offer a promising pathway to the systemic circulation. This is particularly advantageous when a rapid onset of pharmacological action is desired or when the drug is suffering from stability issues or poor biopharmaceutical performance following oral administration. Several cell and tissue-based in vitro and ex vivo models have been developed over the years, with the intention to realistically mimic pulmonary biological barriers. It is the aim of this review to critically discuss the available models regarding their advantages and limitations and to elaborate further which biopharmaceutical questions can and cannot be answered using the existing models.

Dysfunction of epithelial permeability barrier induced by HMGB1 in 2.5D cultures of human epithelial cells

Airway and intestinal epithelial permeability barriers are crucial in epithelial homeostasis. High mobility group box 1 (HMGB1), increased by various stimuli, is involved in the induction of airway inflammation, as well as the pathogenesis of inflammatory bowel disease. HMGB1 enhances epithelial hyperpermeability. Two-and-a-half dimensional (2.5D) culture assays are experimentally convenient and induce cells to form a more physiological tissue architecture than 2D culture assays for molecular transfer mechanism analysis. In 2.5D culture, treatment with HMGB1 induced permeability of FITC-dextran into the lumen formed by human lung, nasal and intestinal epithelial cells. The tricellular tight junction molecule angulin-1/LSR is responsible for the epithelial permeability barrier at tricellular contacts and contributes to various human airway and intestinal inflammatory diseases. In this review, we indicate the mechanisms including angulin-1/LSR and multiple signaling in dysfunction of the epithelial permeability barrier induced by HMGB1 in 2.5D culture of human airway and intestinal epithelial cells.

Effects of HMGB1 on Tricellular Tight Junctions via TGF-β Signaling in Human Nasal Epithelial Cells

The airway epithelium of the human nasal mucosa acts as a physical barrier that protects against inhaled substances and pathogens via bicellular and tricellular tight junctions (bTJs and tTJs) including claudins, angulin-1/LSR and tricellulin. High mobility group box-1 (HMGB1) increased by TGF-β1 is involved in the induction of nasal inflammation and injury in patients with allergic rhinitis, chronic rhinosinusitis, and eosinophilic chronic rhinosinusitis. However, the detailed mechanisms by which this occurs remain unknown. In the present study, to investigate how HMGB1 affects the barrier of normal human nasal epithelial cells, 2D and 2.5D Matrigel culture of primary cultured human nasal epithelial cells were pretreated with TGF-β type I receptor kinase inhibitor EW-7197 before treatment with HMGB1. Knockdown of angulin-1/LSR downregulated the epithelial barrier. Treatment with EW-7197 decreased angulin-1/LSR and concentrated the expression at tTJs from bTJs and increased the epithelial barrier. Treatment with a binder to angulin-1/LSR angubindin-1 decreased angulin-1/LSR and the epithelial barrier. Treatment with HMGB1 decreased angulin-1/LSR and the epithelial barrier. In 2.5D Matrigel culture, treatment with HMGB1 induced permeability of FITC-dextran (FD-4) into the lumen. Pretreatment with EW-7197 prevented the effects of HMGB1. HMGB1 disrupted the angulin-1/LSR-dependent epithelial permeability barriers of HNECs via TGF-β signaling in HNECs.

Effects of histone deacetylase inhibitors Tricostatin A and Quisinostat on tight junction proteins of human lung adenocarcinoma A549 cells and normal lung epithelial cells

Histone deacetylase (HDAC) inhibitors have a potential therapeutic role for non-small cell lung cancer (NSCLC). However, more preclinical studies of HDAC inhibitors in NSCLC and normal lung epithelial cells are required to evaluate their antitumor activities and mechanisms. The bicellular tight junction molecule claudin-2 (CLDN-2) is highly expressed in lung adenocarcinoma tissues and increase the proliferation of adenocarcinoma cells. Downregulation of the tricellular tight junction molecule angulin-1/LSR induces malignancy via EGF-dependent CLDN-2 and TGF-β-dependent cellular metabolism in human lung adenocarcinoma cells. In the present study, to investigate the detailed mechanisms of the antitumor activities of HDAC inhibitors in lung adenocarcinoma, human lung adenocarcinoma A549 cells and normal lung epithelial cells were treated with the HDAC inibitors Trichostatin A (TSA) and Quisinostat (JNJ-2648158) with or without TGF-β. Both HDAC inhibitors increased anguin-1/LSR, decrease CLDN-2, promoted G1 arrest and prevented the migration of A549 cells. Furthermore, TSA but not Quisinostat with or without TGF-β induced cellular metabolism indicated as the mitochondrial respiration measured using the oxygen consumption rate. In normal human lung epithelial cells, treatment with TSA and Quisinostat increased expression of LSR and CLDN-2 and decreased that of CLDN-1 with or without TGF-β in 2D culture. Quisinostat but not TSA with TGF-β increased CLDN-7 expression in 2D culture. Both HDAC inhibitors prevented disruption of the epithelial barrier measured as the permeability of FD-4 induced by TGF-β in 2.5D culture. TSA and Quisinostat have potential for use in therapy for lung adenocarcinoma via changes in the expression of angulin-1/LSR and CLDN-2.

Development of an In Vitro Airway Epithelial-Endothelial Cell Culture Model on a Flexible Porous Poly(Trimethylene Carbonate) Membrane Based on Calu-3 Airway Epithelial Cells and Lung Microvascular Endothelial Cells

Due to the continuing high impact of lung diseases on society and the emergence of new respiratory viruses, such as SARS-CoV-2, there is a great need for in vitro lung models that more accurately recapitulate the in vivo situation than current models based on lung epithelial cell cultures on stiff membranes. Therefore, we developed an in vitro airway epithelial–endothelial cell culture model based on Calu-3 human lung epithelial cells and human lung microvascular endothelial cells (LMVECs), cultured on opposite sides of flexible porous poly(trimethylene carbonate) (PTMC) membranes. Calu-3 cells, cultured for two weeks at an air–liquid interface (ALI), showed good expression of the tight junction (TJ) protein Zonula Occludens 1 (ZO-1). LMVECs cultured submerged for three weeks were CD31-positive, but the expression was diffuse and not localized at the cell membrane. Barrier functions of the Calu-3 cell cultures and the co-cultures with LMVECs were good, as determined by electrical resistance measurements and fluorescein isothiocyanate-dextran (FITC-dextran) permeability assays. Importantly, the Calu-3/LMVEC co-cultures showed better cell viability and barrier function than mono-cultures. Moreover, there was no evidence for epithelial- and endothelial-to-mesenchymal transition (EMT and EndoMT, respectively) based on staining for the mesenchymal markers vimentin and α-SMA, respectively. These results indicate the potential of this new airway epithelial–endothelial model for lung research. In addition, since the PTMC membrane is flexible, the model can be expanded by introducing cyclic stretch for enabling mechanical stimulation of the cells. Furthermore, the model can form the basis for biomimetic airway epithelial–endothelial and alveolar–endothelial models with primary lung epithelial cells.

Organoid Model in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive- fibrosing disease characterized by extensive deposition of extracellular matrix (ECM), scarring of the lung parenchyma. Despite increased awareness of IPF, etiology and physiological mechanism of IPF are unclear. Therefore, preclinical model will require relevant and recapitulative features of IPF. Recently, pluripotent stem cells (PSC)-based organoid studies are emerging as an alternative approach able to recapitulate tissue architecture with remarkable fidelity. Moreover, these biomimetic tissue models can be served to investigate the mechanisms of diverse disease progression. In this review, we will overview the current organoids technology for human disease modeling including lung organoids for IPF.

TGF-β1 increases permeability of ciliated airway epithelia via redistribution of claudin 3 from tight junction into cell nuclei

TGF-β1 is a major mediator of airway tissue remodelling during atopic asthma and affects tight junctions (TJs) of airway epithelia. However, its impact on TJs of ciliated epithelia is sparsely investigated. Herein we elaborated effects of TGF-β1 on TJs of primary human bronchial epithelial cells. We demonstrate that TGF-β1 activates TGF-β1 receptors TGFBR1 and TGFBR2 resulting in ALK5-mediated phosphorylation of SMAD2. We observed that TGFBR1 and -R2 localize specifically on motile cilia. TGF-β1 activated accumulation of phosphorylated SMAD2 (pSMAD2-C) at centrioles of motile cilia and at cell nuclei. This triggered an increase in paracellular permeability via cellular redistribution of claudin 3 (CLDN3) from TJs into cell nuclei followed by disruption of epithelial integrity and formation of epithelial lesions. Only ciliated cells express TGF-β1 receptors; however, nuclear accumulations of pSMAD2-C and CLDN3 redistribution were observed with similar time course in ciliated and non-ciliated cells. In summary, we demonstrate a role of motile cilia in TGF-β1 sensing and showed that TGF-β1 disturbs TJ permeability of conductive airway epithelia by redistributing CLDN3 from TJs into cell nuclei. We conclude that the observed effects contribute to loss of epithelial integrity during atopic asthma.

Radiation-induced H3K9 methylation on E-cadherin promoter mediated by ROS/Snail axis : Role of G9a signaling during lung epithelial-mesenchymal transition

Lung cancer patients who have undergone radiotherapy developed severe complications such as pneumonitis and fibrosis. Upon irradiation, epithelial cells acquire mesenchymal phenotype via a process called epithelial to mesenchymal transition (EMT), which plays a vital role in organ fibrosis. Several mechanisms have been studied on EMT, however, the correlation between radiation-induced EMT and epigenetic changes are not well known. In the present study, we investigated the role of histone methyltransferase G9a on radiation-induced EMT signaling. There was an increase in total global histone methylation level in irradiated epithelial cells. Western blot analysis on irradiated cells showed an increased expression of H3K9me2/3. The pre-treatment of G9a inhibitor enhanced E-cadherin expression and decreased the mesenchymal markers like N-cadherin, vimentin in the radiated group. Surprisingly, radiation-induced ROS generation and pERK1/2 levels were also inhibited by G9a inhibitor BIX01294, which is showing its antioxidant potential. The ChIP-qPCR analysis on the E-cadherin promoter suggested that G9a and Snail might have formed complex to enrich suppressive marker H3K9me2/3. On the whole, our present study suggested that 1] ROS could modify H3K9 methylation via G9a and promote radiation-induced lung EMT in Beas2B and A549 cells 2] E-cadherin promoter enrichment with heterochromatin mark H3K9me2 expression upon irradiation could be modified by regulating G9a methyltransferase.

Long Non-coding RNA CASC15 Promotes Intrahepatic Cholangiocarcinoma Possibly through Inducing PRDX2/PI3K/AKT Axis

Purpose

Intrahepatic cholangiocarcinoma (ICC) is one of the most common liver primary tumors but its treatments are limited. Bioinformatics showed that the expression level of long non-coding RNA cancer-associated susceptibility 15 gene (CASC15) is correlated with ICC progression, but its functional mechanism remains unclear.

Materials and Methods

Tissues from ICC patients, tumor and adjacent tissue, were used for detection of the expression of CASC15. Clinical data were also collected for clinicopathologic and survival analysis. Short interfering RNA and lentiviral short hairpin RNA were used to knock down CASC15 and PRDX2 expression in ICC cell lines, for the analysis of changes of cell function and xenografts. RNA-pulldown and RNA immunoprecipitation assays were used to detect RNA-binding protein, PRDX2. Male nude mice were used for ICC xenografts, and livers were collected after 4 weeks for immunohistochemistry.

Results

CASC15 is highly expressed in ICC tissues and is related to higher TNM stage. Knockdown of CASC15 in ICC cells reduced cell proliferation, migration, invasiveness and increased apoptosis, and G1/S block. PRDX2 bound to CASC15. Knockdown of CASC15 decreased PRDX2 expression which was rescued by the inhibition of proteasome formation. Downregulation of PRDX2 resulted in G1/S block, reduced ICC cell invasion. Downregulation of CASC15 inhibited phosphoinositide 3-kinase (PI3K)/AKT/c-Myc pathway through downregulating of PRDX2 and overexpressed PRDX2 rescued the block. CASC15 knockout in ICC xenografts suppressed tumor development in vivo, decreased the expression of PRDX2 and Ki67 and inhibited PI3K/AKT pathway.

Conclusion

CASC15 promotes ICC possibly by targeting PRDX2 via the PI3K/AKT pathway, indicating poor prognosis and high degree of malignancy of ICC.

Ruthenium(II)-Arene Thiocarboxylates: Identification of a Stable Dimer Selectively Cytotoxic to Invasive Breast Cancer Cells

Ru^II -arene complexes provide a versatile scaffold for novel anticancer drugs. Seven new Ru^II -arene-thiocarboxylato dimers were synthesized and characterized. Three of the complexes (2 a, b and 5) showed promising antiproliferative activities in MDA-MB-231 (human invasive breast cancer) cells, and were further tested in a panel of fifteen cancerous and noncancerous cell lines. Complex 5 showed moderate but remarkably selective activity in MDA-MB-231 cells (IC₅₀ =39±4 μm Ru). Real-time proliferation studies showed that 5 induced apoptosis in MDA-MB-231 cells but had no effect in A549 (human lung cancer, epithelial) cells. By contrast, 2 a and b showed moderate antiproliferative activity, but no apoptosis, in either cell line. Selective cytotoxicity of 5 in aggressive, mesenchymal-like MDA-MB-231 cells over many common epithelial cancer cell lines (including noninvasive breast cancer MCF-7) makes it an attractive lead compound for the development of specifically antimetastatic Ru complexes with low systemic toxicity.

[Intrapulmonary Pharmacokinetics and Drug Distribution Characteristics for the Treatment of Respiratory Diseases]

This study was designed to clarify the intrapulmonary pharmacokinetics and distribution characteristics of drugs in order to develop better therapies for respiratory diseases, including respiratory infections and pulmonary fibrosis. The distribution characteristics of three macrolide antimicrobial agents-clarithromycin, azithromycin, and telithromycin-in plasma, lung epithelial lining fluid (ELF), and alveolar macrophages (AMs), were examined for the optimization of antimicrobial therapy. The time course of the uptake of these agents in ELF and AMs, following oral administration to rats, resulted in markedly higher concentrations than that in plasma. The high concentration of the agents in AMs was due to their sustained distribution to ELF via multidrug resistance protein 1 and to high uptake by AMs themselves via active transport mechanisms and trapping and/or binding in acidic organelles. The intrapulmonary pharmacokinetics of aerosolized model compounds administered to animals with bleomycin-induced pulmonary fibrosis via aerosol formulations of model compounds (MicroSprayer) were then evaluated. The concentrations of these compounds in the plasma of pulmonary fibrotic rats were markedly higher than in that of control rats. The expression of epithelial tight junctions decreased in pulmonary fibrotic lesions. The accumulation of extracellular matrix inhibited the intrapulmonary distribution of aerosolized model compounds, indicating that aerosolized drugs are easily absorbed after leakage through damaged alveolar epithelia, but cannot become widely distributed in the lungs because of interruption by the extracellular matrix. This review provides useful findings for the development of therapies for respiratory infections and pulmonary fibrosis.

Chitosan-based binary dry powder inhaler carrier with nanometer roughness for improving in vitro and in vivo aerosolization performance

Suitable nanometer roughness favors interactions between drugs and carriers, and it is a promising approach to enhance the aerosolization performance of carrier-based dry powder inhalers (DPIs). In this study, by altering the molecular migration rates, chitosan-based binary carriers (CBBCs) with nanometer roughness were fabricated for DPIs. Comprehensive physicochemical characterizations were conducted to elucidate the formation mechanism of the CBBCs. It was hypothesized that different constituent ratios in the formulations would result in different assembling of the particles and diverse roughness scales. The fine particle fractions (FPF, approximately 40~60%) of nanometer roughness CBBC-based DPI formulations were satisfactory, demonstrating the enhancement of the in vitro aerodynamic performance. The positive correlation (R2 = 0.9883) between the nanometer roughness and FPF was revealed, and the surface roughness of 20 nm might achieve the best aerosolization performance. CBBCs (optimal formulations) showed no difference in cytotoxicity on A549 and Calu-3 cells (p > 0.05). Additionally, the increased Cmax and AUC0-8h of the formulation with the nanometer roughness (p < 0.05) were observed in pharmacokinetic studies, which resulted from the improved in vivo aerosolization performance. In summary, the CBBCs were a prospective tool to improve the in vitro and in vivo aerosolization performance of DPIs. Graphical abstract ᅟ.

Polo-like kinase 4 mediates epithelial-mesenchymal transition in neuroblastoma via PI3K/Akt signaling pathway

Neuroblastoma (NB) is the most common malignant tumor in infancy and most common extracranial solid tumor in childhood. With the improvement of diagnosis and treatment, the survival rate of patients with low-risk and intermediate-risk NB can reach up to 90%. In contrast, for high-risk NBs, the long-term survival rate is still <40% because of heterogeneity of this tumor. The pathogenesis of NB is still not explicit, therefore it is of great significance to explore the mechanism of NB tumorigenesis and discover new therapeutic targets for NB. Polo-like kinase 4 (PLK4), one of the polo-like kinase family members, is an important regulator of centriole replication. The aberrant expression of PLK4 was found in several cancers and a recent study has unraveled a novel function of PLK4 as a mediator of invasion and metastasis in Hela and U2OS cells. However, the function of PLK4 in NB development and progression remains to be elucidated. The study showed the expression level of PLK4 in NB tissues was remarkably upregulated and high expression of PLK4 was negatively correlated with clinical features and survival, which suggested that PLK4 could be a potential tumor-promoting factor of NB. Functional studies indicated downregulation of PLK4 suppressed migration and invasion and promoted apoptosis in NB cells. Further experiments showed that downregulation of PLK4 in NB cells inhibited EMT through the PI3K/Akt signaling pathway. Animal experiments demonstrated that the downregulation of PLK4 in SK-N-BE(2) cells dramatically suppressed tumorigenesis and metastasis. PLK4 may be a promising therapeutic target for NB.