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Fibroblast-to-myofibroblast (FibroMF) differentiation is crucial for embryogenesis and organ fibrosis. Although transforming growth factor-[beta] (TGF[beta]) is the primary mediator of FibroMF differentiation, the type-I receptor (TGF[beta]RI) responsible for this has not yet been confirmed. In the current study, we investigated the ALK1 and ALK5 expressions in TGF[beta]1-stimulated NIH 3T3 fibroblasts to compare with the data from the Gene Expression Omnibus (GEO) repository. In our results, whereas TGF[beta]1 treatment promoted FibroMF differentiation accompanied by increased ALK5 expression and reduced ALK1 expression, TGF[beta]1induced FibroMF differentiation and increased [alpha]-smooth muscle actin ([alpha]SMA) and ALK5 expression were inhibited by cotreatment with ALK5 inhibitor SB431542. GEO database analysis indicated increased ALK5 expression and reduced ALK1 expression in fibrotic compared to normal mouse or human tissues correlating with organ fibrosis progression. Finally, the inhibitors of Akt, mTOR, and [beta]-catenin suppressed TGF[beta]1-induced ALK5 expression, indicating that the Akt pathway promotes FibroMF differentiation via ALK5 expression and fibrosis. Key words: ALK1, ALK5, TGF[beta]1, myofibroblast, fibrosis. La differentiation du fibroblaste en myofibroblaste (Fibro en MF) est un phenomene crucial pour l'embryogenese et la fibrose des organes. Bien que le facteur de croissance transformant [beta] (TGF[beta]) soit le principal mediateur de la differentiation du Fibro en MF, le recepteur de type 1 (TGF[beta]R1) n'a pas encore ete confirme comme en etant responsable. Dans les presents travaux, nous avons etudie l'expression de l'ALK1 et de l'ALK5 dans les fibroblastes NIH 3T3 stimules avec le TGF[beta]1 aux fins de comparaisonavec les donnees de la base GEO (pour<< Gene Expression Omnibus>>). Selon nos resultats, l'administrationde TGF[beta]1 favorisait la differentiation du Fibro en MF accompagnee d'une augmentation de l'expression de l'ALK5 et d'une diminution de l'expression de l'ALK1. La differentiation du Fibro en MF engendree par le TGF[beta]1 ainsi que la hausse de l'actine du muscle lisse [alpha] (ou [alpha]SMA pour <>) et de l'expression de l'ALK5 etaient inhibees par l'administration concomitante de SB431542, un inhibiteur de l'ALK5. L'etude de la base de donnees GEO a montre une augmentation de l'expression de l'ALK5 avec une diminution de l'expression de l'ALK1 dans le tissu fibreux comparativement aux tissus normaux de souris ou d'humains de maniere proportionnelle a revolution de la fibrose. Enfin, les inhibiteurs de l'Akt, de mTOR et de la [beta]-catenine inhibaient l'augmentation de l'expression de l'ALK5 engendree par le TGF[beta]1, ce qui montrait que la voie de signalisation de l'Akt favorise la differentiation du Fibro en MF par l'intermediaire de l'augmentation de l'expression de l'ALK5 et de la fibrose. [Traduit par la Redaction] Mots-cles: ALK1, ALK5, TGF[beta]1, myofibroblaste, fibrose., Introduction Fibroblast-to-myofibroblast (FibroMF) differentiation is the hallmark of embryogenesis (Roulis and Flavell 2016), wound healing, and organ fibrosis (Weiskirchen et al. 2019). The integral role of the transforming growth factor-[beta] [...]

Cell junctions maintain the blood-tissue barriers to preserve vascular and tissue integrity. Viral infections reportedly modulate cell–cell junctions to facilitate their invasion. However, information on the effect of COVID-19 infection on the gene expression of cell junction and cytoskeletal proteins is limited. Using the Gene Expression Omnibus and Reactome databases, we analyzed the data on human lung A549, NHBE, and Calu-3 cells for the expression changes in cell junction and cytoskeletal proteins by SARS-CoV-2 (CoV-2) infection. The analysis revealed changes in 3,660 genes in A549, 100 genes in NHBE, and 592 genes in Calu-3 cells with CoV-2 infection. Interestingly, EGOT (9.8-, 3- and 8.3-fold; p <.05) and CSF3 (4.3-, 33- and 56.3-fold; p <.05) were the only two genes significantly elevated in all three cell lines (A549, NHBE and Calu-3, respectively). On the other hand, 39 genes related to cell junctions and cytoskeleton were modulated in lung cells, with DLL1 demonstrating alterations in all cells. Alterations were also seen in several miRNAs associated with the cell junction and cytoskeleton genes modulated in the analysis. Further, matrix metalloproteinases involved in disease pathologies, including MMP-3, -9, and -12 demonstrated elevated expression on CoV-2 infection (p <.05). The study findings emphasize the integral role of cell junction and cytoskeletal genes in COVID-19, suggesting their therapeutic potential. Our analysis also identified a distinct EGOT gene that has not been previously implicated in COVID-19. Further studies on these newly identified genes and miRNAs could lead to advances in the pathogenesis and therapeutics of COVID-19. [ABSTRACT FROM AUTHOR]

Endothelial‐to‐mesenchymal transition (EndMT) and fibroblast‐to‐myofibroblast (FibroMF) differentiation are frequently reported in organ fibrosis. Stromelysin1, a matrix metalloprotease‐3 (MMP3) has been indicated in vascular pathologies and organ injuries that often lead to fibrosis. In the current study, we investigated the role of stromelysin1 in EndMT and FibroMF differentiation, which is currently unknown. In our results, whereas TGFβ2 treatment of endothelial cells (ECs) induced EndMT associated with increased expression of stromelysin1 and mesenchymal markers such as α‐smooth muscle actin (αSMA), N‐cadherin, and activin linked kinase‐5 (ALK5), inhibition of stromelysin1 blunted TGFβ2‐induced EndMT. In contrast, treatment of NIH‐3T3 fibroblasts with TGFβ1 promoted FibroMF differentiation accompanied by increased expression of αSMA, N‐cadherin, and ALK5. Intriguingly, stromelysin1 inhibition in TGFβ1‐stimulated myofibroblasts further exacerbated fibroproliferation with increased FibroMF marker expression. Gene Expression Omnibus (GEO) data analysis indicated increased stromelysin1 expression associated with EndMT and decreased stromelysin1 expression in human pulmonary fibrosis fibroblasts. In conclusion, our study has identified that EndMT and FibroMF differentiation are reciprocally regulated by stromelysin1. [ABSTRACT FROM AUTHOR]

Epithelial and endothelial cell-cell contacts are established and maintained by several intercellular junctional complexes. These structurally and biochemically differentiated regions on the plasma membrane primarily include tight junctions (TJs), and anchoring junctions. While the adherens junctions (AJs) provide essential adhesive and mechanical properties, TJs hold the cells together and form a near leak-proof intercellular seal by the fusion of adjacent cell membranes. AJs and TJs play essential roles in vascular permeability. Considering their involvement in several key cellular functions such as barrier formation, proliferation, migration, survival, and differentiation, further research is warranted on the composition and signaling pathways regulating cell-cell junctions to develop novel therapeutics for diseases such as organ injuries. The current review article presents our current state of knowledge on various cell-cell junctions, their molecular composition, and mechanisms regulating their expression and function in endothelial and epithelial cells. [ABSTRACT FROM AUTHOR]

The endothelium is a thin layer of squamous cells that acts as a semipermeable barrier regulating vascular permeability to let molecules pass through it thereby maintaining tissue fluid homeostasis. Physiological increase in endothelial or vascular permeability is transient, transpired by post-tissue injury during the initial phases of healing, whereas pathological permeability is persistent commonly witnessed in conditions such as atherosclerosis, chronic inflammation, tumor growth, and diabetic retinopathy. The in vivo or in situ use of animal models in the assessment of permeability not only raises inevitable ethical concerns but also confers difficulty to apply to high-throughput screening. Therefore, there is an ever-increasing dependency on in vitro studies to assess drug permeability, and various research programs have suffered to develop appropriate in vitro assays for measurement and prediction. In vitro models that both mimic in vivo microvascular endothelium and can be utilized to record changes in endothelial permeability are vital in delineating the mechanisms involved in the prevention and treatment of disorders related to vascular permeability. The Transwell ® and the electric cell-substrate impedance sensing (ECIS) assays are extensively used to assess the trans-endothelial permeability of solutes such as albumin, dextrans, and sucrose across endothelial monolayers and based on electrical resistance, etc. These models have several advantages such as the ease to perform and avoid the complexities of using a live animal.

Whereas physiological vascular permeability (VP) mediates selective transport of plasma, electrolytes, proteins, and cells across an intact endothelial barrier, pathological VP results in the loss of endothelial barrier integrity. Whereas physiological VP is a feature of regular host defense and tissue repair, compromised barrier function may lead to aberrant vascular leakage, concurrent tissue edema, and inflammation eventually causing life-threatening conditions such as acute lung injury or acute respiratory distress syndrome, cancer, kidney injury, etc. Measurement of VP helps to identify, design, and optimize anti-leak therapies. Further, it can define the effect of a stimulus or a gene modulation in endothelial-barrier regulation. The degree of VP can be of importance to determine the stage of cancer and disease prognosis. This chapter discusses Miles assay, which is a well-established, relatively simple, and a reliable in vivo technique to assess VP as a surrogate measurement. Although a reliable technique, Miles assay is time-consuming, and the technique does not consider the compounding factors that may increase VP independently of endothelial-barrier regulation, such as blood pressure or blood flow. As an alternative, we describe fluorescein isothiocyanate-dextran lung permeability assay, a method that can also be adapted to measure VP and edema in other organs such as the brain and kidney.

The adaptive immune response could play a major role in the resolution of lung injury. Although regulatory T cells (Tregs) have been implicated in promoting the resolution of lung injury, therapeutic strategies to enhance Treg quantity and activity at the site of injury need further exploration. In the current study, Akt inhibition using triciribine (TCBN), given 48 h after lipopolysaccharide (LPS) administration, increased Tregs-promoted resolution of acute lung injury (ALI). TCBN treatment enhanced the resolution of LPS-induced ALI on day 7 by reducing pulmonary edema and neutrophil activity associated with an increased number of CD4 + /FoxP3 + /CD103 + and CTLA4 + effector Tregs, specifically in the injured lungs and not in the spleen. Treatment of EL-4 T-lymphocytes with two Akt inhibitors (TCBN and MK-2206) for 72 h resulted in increased FoxP3 expression in vitro. On the other end, Treg-specific PTEN knockout (PTEN Treg KO) mice that have a higher Akt activity in its Tregs exhibited a significant impairment in ALI resolution, increased edema, and neutrophil activity associated with a reduced number of CD4 + /FoxP3 + /CD103 + and CTLA4 + effector Tregs as compared with the control group. In conclusion, our study identifies a potential target for the treatment of late-stage ALI by promoting resolution through effector Treg-mediated suppression of inflammation.

Background: Adverse drug reaction (ADR) is considered to be the sixth leading cause of death. The incidence rate estimates approximately 2% of hospital admissions are due to ADRs., Objective: To monitor ADRs in Pulmonology department of a tertiary care hospital patient with pulmonary diseases in an inpatient department of pulmonology., Materials and Methods: A prospective, single centered, observational and open labeled study was carried out in Princess Esra Hospital. The patient population was broadly divided into four categories based on diagnosis - chronic obstructive pulmonary disease, Infections, Asthma and Others. Suspected ADRs were reported, analyzed, and causality assessment was carried out using Naranjo's algorithm scale., Results: A total of 302 patients were observed, of which 98 patients experienced ADRs, which accounted for 32.23% of the incidence and totally 160 ADEs were observed. Adult Patients were found to have higher incidence (32.09%) while the incidence rate was slightly greater in geriatric patients (32.39%). The highest incidence of ADEs were found in others group (78.57%). Majority of ADRs were suspected to be due to theophylline (19.39%). Gastrointestinal system (38.75%) was the most common organ system affected due to ADRs. Drug was withdrawn in 12 patients, and specific treatment was administered to 32 patients in view of clinical status. Specific treatment for the management of suspected reaction was administered in 32.65% of ADR reports., Conclusion: A relatively high incidence of adverse drug events (32.2%) have been recorded which shows that not only Geriatric patients, but also adults are more susceptible to adverse drug effects. A number of drugs in combination were used, and ADEs often get multiplied. Careful therapeutic monitoring and dose individualization is necessary.