Cell-cell interactions and communication dynamics in lung fibrosis.

Cell-cell interactions are essential components of coordinated cell function in lung homeostasis. Lung diseases involve altered cell-cell interactions and communication between different cell types, as well as between subsets of cells of the same type. The identification and understanding of intercellular signaling in lung fibrosis offer insights into the molecular mechanisms underlying these interactions and their implications in the development and progression of lung fibrosis. A comprehensive cell atlas of the human lung, established with the facilitation of single-cell RNA transcriptomic analysis, has enabled the inference of intercellular communications using ligand-receptor databases. In this review, we provide a comprehensive overview of the modified cell-cell communications in lung fibrosis. We highlight the intricate interactions among the major cell types within the lung and their contributions to fibrogenesis. The insights presented in this review will contribute to a better understanding of the molecular mechanisms underlying lung fibrosis and may guide future research efforts in developing targeted therapies for this debilitating disease.

A branched polymer-based agent for efficient and precise targeting of fibrosis diseases by magnetic resonance imaging.

Herein, we synthesized and characterized gadolinium-based hyperbranched polymers, POADGd and PODGd, through RAFT polymerization as magnetic resonance imaging (MRI) contrast agents for detecting fibrosis. POADGd and PODGd contain biocompatible short-chain OEGMA to prolong blood circulation, and they can be decomposed in response to ROS after MRI examination to prevent potential accumulation. The relaxivities of POADGd and PODGd are 9.81 mM-1 s-1 and 9.58 mM-1 s-1 respectively, which are significantly higher than that of DTPA-Gd, a clinically used agent (3.74 mM-1 s-1). In comparison with PODGd, POADGd can specifically target allysine in fibrosis tissues through its oxyamine groups. Therefore, it displays a sharp spatial resolution and a high signal-to-noise ratio in the liver and lung fibrosis tissue at a field strength of 3.0 T or 7.0 T, and the morphology of these fibrosis tissues is accurately delineated. Our MRI diagnosis results based on POADGd are highly aligned with those from pathological examinations, while MRI diagnosis could avoid invasive biopsy. In addition, POADGd shows excellent biosafety and low toxicity. Therefore, POADGd could be applied to non-invasively and accurately diagnose liver and lung fibrosis diseases.

The protein disulfide isomerase A3 and osteopontin axis promotes influenza-induced lung remodelling.

BACKGROUND AND PURPOSE: Fibrotic lung remodelling after a respiratory viral infection represents a debilitating clinical sequela. Studying or managing viral-fibrotic sequela remains challenging, due to limited therapeutic options and lack of understanding of mechanisms. This study determined whether protein disulfide isomerase A3 (PDIA3) and secreted phosphoprotein 1 (SPP1), which are associated with pulmonary fibrosis, can promote influenza-induced lung fibrotic remodelling and whether inhibition of PDIA3 or SPP1 can resolve viral-mediated fibrotic remodelling. EXPERIMENTAL APPROACH: A retrospective analysis of TriNetX data sets was conducted. Serum from healthy controls and influenza A virus (IAV)-infected patients was analysed. An inhibitor of PDIA3, punicalagin, and a neutralizing antibody for SPP1 were administered in mice. Macrophage cells treated with macrophage colony-stimulating factor (M-CSF) were used as a cell culture model. KEY RESULTS: The TriNetX data set showed an increase in lung fibrosis and decline in lung function in flu-infected acute respiratory distress syndrome (ARDS) patients compared with non-ARDS patients. Serum samples revealed a significant increase in SPP1 and PDIA3 in influenza-infected patients. Lung PDIA3 and SPP1 expression increased following viral infection in mouse models. Punicalagin administration 2 weeks after IAV infection in mice caused a significant decrease in lung fibrosis and improved oxygen saturation. Administration of neutralizing SPP1 antibody decreased lung fibrosis. Inhibition of PDIA3 decreased SPP1secretion from macrophages, in association with diminished disulfide bonds in SPP1. CONCLUSION AND IMPLICATIONS: The PDIA3-SPP1 axis promotes post-influenza lung fibrosis in mice and that pharmacological inhibition of PDIA3 or SPP1 can treat virus-induced lung fibrotic sequela.

Assessment of Imatinib Anti-Remodeling Activity on a Human Precision Cut Lung Slices Model.

Recent studies have emphasized the critical role of alteration in cellular plasticity in the development of fibrotic disorders, particularly pulmonary fibrosis, prompting further investigation into molecular mechanisms and therapeutic approaches. In this context, Precision Cut Lung Slices (PCLSs) emerge as a valuable ex vivo research tool. The process of PCLSs generation preserves most features of the naïve lung tissue, such as its architecture and complex cellular composition. We previously stimulated normal lung PCLSs with two different stimuli (fibrotic cocktail, composed by platelet lysate and TGFß, or neutrophil extracellular traps) and we observed a significant elevation of Epithelial-Mesenchymal Transition (EMT) markers from 24 h to 72 h of culture. The aim of our work was to exploit this PCLSs based ex vivo model of EMT, to evaluate the effect of imatinib, an old tyrosine kinase inhibitor with reported anti-remodeling activities in vitro and in animal models. Imatinib treatment significantly decreased α-SMA and collagen expression already starting from 24 h on stimulated PCLS. Imatinib showed a significant toxicity on unstimulated cells (3-fold increase in ACTA2 expression levels at 24 h, 1.5-fold increase in COL1A1 expression levels at 24 h, 2-fold increase in COL3A1 expression levels at 72 h). Further evaluations on specific cell lines pointed out that drug effects were mainly directed towards A549 and LFs. In conclusion, our model confirms the anti-remodeling activity of imatinib but suggests that its direct delivery to alveolar epithelial cells as recently attempted by inhalatory preparation of the drug might be associated with a non-negligible epithelial cell toxicity.

Mechanical Stretch Induces Senescence of Lung Epithelial Cells and Drives Fibroblast Activation by Paracrine Mechanisms.

Severe lung injury requiring mechanical ventilation may lead to secondary fibrosis. Senescence, a cell response characterized by cell cycle arrest and a shift towards a proinflammatory/profibrotic phenotype, is one of the involved mechanisms. Here, we explore the contribution of mechanical stretch as trigger of senescence of the respiratory epithelium and its link with fibrosis. Human lung epithelial cells and fibroblasts were exposed in vitro to mechanical stretch, and senescence assessed. In addition, fibroblasts were exposed to culture media preconditioned by senescent epithelial cells and their activation was studied. Transcriptomic profiles from stretched, senescent epithelial cells and activated fibroblasts were combined to identify potential activated pathways. Finally, the senolytic effects of digoxin were tested in these models. Mechanical stretch induced senescence in lung epithelial cells, but not in fibroblasts. This stretch-induced senescence has specific features compared to senescence induced by doxorubicin. Fibroblasts were activated after exposure to supernatants conditioned by epithelial senescent cells. Transcriptomic analyses revealed notch signaling as a potential responsible for the epithelial-mesenchymal crosstalk, as blockade of this pathway inhibits fibroblast activation. Treatment with digoxin reduced the percentage of senescent cells after stretch and ameliorated the fibroblast response to preconditioned media. These results suggest that lung fibrosis in response to mechanical stretch may be caused by the paracrine effects of senescent cells. This pathogenetic mechanism can be pharmacologically manipulated to improve lung repair.

Dopaminylation of endothelial TPI1 suppresses ferroptotic angiocrine signals to promote lung regeneration over fibrosis.

Lungs can undergo facultative regeneration, but handicapped regeneration often leads to fibrosis. How microenvironmental cues coordinate lung regeneration via modulating cell death remains unknown. Here, we reveal that the neurotransmitter dopamine modifies the endothelial niche to suppress ferroptosis, promoting lung regeneration over fibrosis. A chemoproteomic approach shows that dopamine blocks ferroptosis in endothelial cells (ECs) via dopaminylating triosephosphate isomerase 1 (TPI1). Suppressing TPI1 dopaminylation in ECs triggers ferroptotic angiocrine signaling to aberrantly activate fibroblasts, leading to a transition from lung regeneration to fibrosis. Mechanistically, dopaminylation of glutamine (Q) 65 residue in TPI1 directionally enhances TPI1's activity to convert dihydroxyacetone phosphate (DHAP) to glyceraldehyde 3-phosphate (GAP), directing ether phospholipid synthesis to glucose metabolism in regenerating lung ECs. This metabolic shift attenuates lipid peroxidation and blocks ferroptosis. Restoring TPI1 Q65 dopaminylation in an injured endothelial niche overturns ferroptosis to normalize pro-regenerative angiocrine function and alleviate lung fibrosis. Overall, dopaminylation of TPI1 balances lipid/glucose metabolism and suppresses pro-fibrotic ferroptosis in regenerating lungs.

Effects of home-based telerehabilitation-assisted inspiratory muscle training in patients with idiopathic pulmonary fibrosis: A randomized controlled trial.

BACKGROUND AND OBJECTIVE: There are few studies that have used inspiratory muscle training (IMT) as an intervention for patients with isolated idiopathic pulmonary fibrosis (IPF). This study aimed to investigate and interpret the effects of home-based telerehabilitation-assisted IMT in patients with IPF. METHODS: Twenty-eight participants with IPF took part in the study. Lung function tests, functional exercise capacity by 6-min walk distance (6MWD), dyspnoea perception by modified medical research council dyspnoea scale (mMRC), and inspiratory muscle strength by maximal inspiratory pressure (MIP) were assessed. IMT was performed twice a day, 7 days/week, for 8 weeks. The intervention group (n = 14) performed IMT at 50% of their baseline MIP while the control group (n = 14) performed IMT without applied resistance. Loading intensity was progressed by keeping the load at 4-6 on a modified Borg scale for the highest tolerable perceived respiratory effort for each patient. RESULTS: Dyspnoea based on mMRC score (p < 0.001, η2 effect size = 0.48) significantly decreased within the intervention group compared with the control group. There were significant increases in the intervention group compared to the control group based on 6MWD (p < 0.001, η2 effect size = 0.43), MIP (p = 0.006, η2 effect size = 0.25) and MIP % predicted (p = 0.008, η2 effect size = 0.25). CONCLUSION: The findings of this study suggest that an 8-week home-based telerehabilitation-assisted IMT intervention produced improvements in inspiratory muscle strength, leading to improvements in functional exercise capacity and dyspnoea.

Wharton's jelly mesenchymal stem cells: Future regenerative medicine for clinical applications in mitigation of radiation injury.

Wharton's jelly mesenchymal stem cells (WJ-MSCs) are gaining significant attention in regenerative medicine for their potential to treat degenerative diseases and mitigate radiation injuries. WJ-MSCs are more naïve and have a better safety profile, making them suitable for both autologous and allogeneic transplantations. This review highlights the regenerative potential of WJ-MSCs and their clinical applications in mitigating various types of radiation injuries. In this review, we will also describe why WJ-MSCs will become one of the most probable stem cells for future regenerative medicine along with a balanced view on their strengths and weaknesses. Finally, the most updated literature related to both preclinical and clinical usage of WJ-MSCs for their potential application in the regeneration of tissues and organs will also be compiled.

Interleukin-11 drives fibroblast metabolic reprogramming in crystalline silica-induced lung fibrosis.

Environmental exposure to crystalline silica (CS) particles is common and occurs during natural, industrial, and agricultural activities. Prolonged inhalation of CS particles can cause silicosis, a serious and incurable pulmonary fibrosis disease. However, the underlying mechanisms remain veiled. Herein, we aim to elucidate the novel mechanisms of interleukin-11 (IL-11) driving fibroblast metabolic reprogramming during the development of silicosis. We observed that CS exposure induced lung fibrosis in mice and activated fibroblasts, accompanied by increased IL-11 expression and metabolic reprogramming switched from mitochondrial respiration to glycolysis. Besides, we innovatively uncovered that elevated IL-11 promoted the glycolysis process, thereby facilitating the fibroblast-myofibroblast transition (FMT). Mechanistically, CS-stimulated IL-11 activated the extracellular signal-regulated kinase (ERK) pathway and the latter increased the expression of hypoxia inducible factor-1α (HIF-1α) via promoting the translation and delaying the degradation of the protein. HIF-1α further facilitated glycolysis, driving the FMT process and ultimately the formation of silicosis. Moreover, either silence or neutralization of IL-11 inhibited glycolysis augmentation and attenuated CS-induced lung myofibroblast generation and fibrosis. Overall, our findings elucidate the role of IL-11 in promoting fibroblast metabolic reprogramming through the ERK-HIF-1α axis during CS-induced lung fibrosis, providing novel insights into the molecular mechanisms and potential therapeutic targets of silicosis.

Exploring the Interplay between Cellular Senescence, Immunity, and Fibrosing Interstitial Lung Diseases: Challenges and Opportunities.

Fibrosing interstitial lung diseases (ILDs) are characterized by the gradual and irreversible accumulation of scar tissue in the lung parenchyma. The role of the immune response in the pathogenesis of pulmonary fibrosis remains unclear. In recent years, substantial advancements have been made in our comprehension of the pathobiology driving fibrosing ILDs, particularly concerning various age-related cellular disturbances and immune mechanisms believed to contribute to an inadequate response to stress and increased susceptibility to lung fibrosis. Emerging studies emphasize cellular senescence as a key mechanism implicated in the pathobiology of age-related diseases, including pulmonary fibrosis. Cellular senescence, marked by antagonistic pleiotropy, and the complex interplay with immunity, are pivotal in comprehending many aspects of lung fibrosis. Here, we review progress in novel concepts in cellular senescence, its association with the dysregulation of the immune response, and the evidence underlining its detrimental role in fibrosing ILDs.

Mechanism of action of miR-15a-5p and miR-152-3p in paraquat-induced pulmonary fibrosis through Wnt/ß-catenin signaling mediation.

Background: miRNAs are small, conserved, single-stranded non-coding RNA that are typically transported by exosomes for their functional roles. The therapeutic potential of exosomal miRNAs has been explored in various diseases including breast cancer, pancreatic cancer, cholangiocarcinoma, skin diseases, Alzheimer's disease, stroke, and glioma. Pathophysiological processes such as cellular inflammation, apoptosis, necrosis, immune dysfunction, and oxidative stress are closely associated with miRNAs. Internal and external factors such as tissue ischemia, hypoxia, pathogen infection, and endotoxin exposure can trigger these reactions and are linked to miRNAs. Paraquat-induced fibrosis is a protracted process that may not manifest immediately after injury but develops during bodily recovery, providing insights into potential miRNA intervention treatments. Rationale: These findings could potentially be applied for further pharmaceutical research and clinical therapy of paraquat-induced pulmonary fibrosis, and are likely to be of great interest to clinicians involved in lung fibrosis research. Methodology: Through a literature review, we identified an association between miR-15a-5p and miR-152-3p and their involvement in the Wnt signaling pathway. This allowed us to deduce the molecular mechanisms underlying regulatory interactions involved in paraquat-induced lung fibrosis. Results: miR-15a-5p and miR-152-3p play roles in body repair processes, and pulmonary fibrosis can be considered a form of reparative response by the body. Although the initial purpose of fibrotic repair is to restore normal body function, excessive tissue fibrosis, unlike scar formation following external skin trauma, can significantly and adversely affect the body. Modulating the Wnt/ß-catenin signaling pathway is beneficial in alleviating tissue fibrosis in various diseases. Conclusions: In this study, we delineate the association between miR-15a-5p and miR-152-3p and the Wnt/ß-catenin signaling pathway, presenting a novel concept for addressing paraquat-induced pulmonary fibrosis.

Prognostic impact of cytokines and chemokines in bronchoalveolar lavage fluid on acute exacerbation of fibrosing interstitial lung disease.

BACKGROUND AND OBJECTIVE: Acute exacerbation of fibrosing interstitial lung disease (AE-FILD) is a serious condition with a high mortality rate. We aimed to comprehensively analyze cytokines in bronchoalveolar lavage fluid and their association with the clinical course of AE-FILD. METHODS: We retrospectively enrolled 60 patients with AE-FILD who underwent bronchoalveolar lavage. We comprehensively measured 44 cytokines and chemokines in the obtained bronchoalveolar lavage fluid using a Luminex analyzer. Patients were grouped into those who died within 90 days (non-survival group) and survived beyond 90 days (survival group) to investigate the association of the levels of cytokines and chemokines with mortality. RESULTS: The levels of matrix metalloproteinase 1 (p = 0.003), granulocyte-macrophage colony-stimulating factor (p = 0.040), interleukin 6 (p = 0.047), interleukin 8 (p = 0.050), monocyte chemoattractant protein-1 (p = 0.043), and eotaxin (p = 0.044) were significantly higher in the non-survival group than in the survival group. In the receiver operating characteristic analysis, their areas under the curve were 0.80, 0.68, 0.71, 0.70, 0.70, and 0.72, respectively. Using machine learning with these six cytokines and chemokines, the predictive accuracy for the survival group was 0.94. CONCLUSIONS: Our study demonstrated that several cytokines and chemokines in bronchoalveolar lavage fluid could be prognostic predictors in patients with AE-FILD.

Rheumatoid arthritis extra-articular lung disease: new insights on pathogenesis and experimental drugs.

INTRODUCTION: Pulmonary involvement is one of the most common extra-articular manifestations of rheumatoid arthritis (RA), a systemic inflammatory disease characterized by joint swelling and tenderness. All lung compartments can be interested in the course of RA, including parenchyma, airways, and, more rarely, pleura and vasculature. AREAS COVERED: The aim of this paper is to review the main RA lung manifestations, focusing on pathogenesis, clinical and therapeutic issues of RA-related interstitial lung disease (ILD). Despite an increasing number of studies in the last years, pathogenesis of RA-ILD remains largely debated and the treatment of RA patients with lung involvement is still challenging in these patients. EXPERT OPINION: Management of RA-ILD is largely based on expert-opinion. Due to the broad clinical manifestations, including both joints and pulmonary involvement, multidisciplinary discussion, including rheumatologist and pulmonologist, is essential, not only for diagnosis, but also to evaluate the best therapeutic approach and follow-up. In fact, the coexistence of different lung manifestations may influence the treatment response and safety. The identification of biomarkers and risk-factors for an early identification of RA patients at risk of developing ILD remains a need that still needs to be fulfilled, and that will require further investigation in the next years.

High antinuclear antibody titer is associated with increased mortality risk in patients with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a diagnosis of exclusion, requiring that potential etiologies of interstitial lung disease be ruled out. Antinuclear antibody (ANA) testing is commonly performed in individuals with IPF, but the clinical significance of ANA positivity remains uncertain. A retrospective search identified 161 patients diagnosed with IPF between May 2010 and January 2021. Data on ANA titers at the time of diagnosis were available in all cases. Mean age of the patients was 66.4 ± 9.6 years; 70.8% were male. ANA titers were high (≥ 1:160) in 25.4% of the cohort. Baseline characteristics were comparable between those with high and low ANA titers. During follow-up (median 28 months), 93 patients (57%) died. On Cox proportional-hazards analysis with lung transplantation entered as a competing risk and adjusting for potential confounders (age, sex, and baseline forced vital capacity and diffusing lung capacity for carbon monoxide), ANA ≥ 1:160, as a dichotomized variable, was significantly associated with case-specific mortality (HR 2.25, 95% CI 1.14-4.42, P = 0.02) and older age (for each 10-year increment, HR 1.55, 95% CI 1.07-2.25, P = 0.02). High ANA titers appear to be associated with increased mortality in IPF. This finding emphasizes the potential prognostic value of ANA testing. Further studies are needed to validate these findings and explore their implications for patient management.

Assessing Lung Fibrosis with ML-Assisted Minimally Invasive OCT Imaging.

This paper presents a combined optical coherence tomography (OCT) imaging/machine learning (ML) technique for real-time analysis of lung tissue morphology to determine the presence and level of invasiveness of idiopathic lung fibrosis (ILF). This is an important clinical problem as misdiagnosis is common, resulting in patient exposure to costly and invasive procedures and substantial use of healthcare resources. Therefore, biopsy is needed to confirm or rule out radiological findings. Videoscopic-assisted thoracoscopic wedge biopsy (VATS) under general anesthesia is typically necessary to obtain enough tissue to make an accurate diagnosis. This kind of biopsy involves the placement of several tubes through the chest wall, one of which is used to cut off a piece of lung to send for evaluation. The removed tissue is examined histopathologically by microscopy to confirm the presence and the pattern of fibrosis. However, VATS pulmonary biopsy can have multiple side effects, including inflammation, tissue morbidity, and severe bleeding, which further degrade the quality of life for the patient. Furthermore, the results are not immediately available, requiring tissue processing and analysis. Here, we report an initial attempt of using ML-assisted polarization sensitive OCT (PS-OCT) imaging for lung fibrosis assessment. This approach has been preliminarily tested on a rat model of lung fibrosis. Our preliminary results show that ML-assisted PS-OCT imaging can detect the presence of ILF with an average of 77% accuracy and 89% specificity.

Micro-CT-assisted identification of the optimal time-window for antifibrotic treatment in a bleomycin mouse model of long-lasting pulmonary fibrosis.

Idiopathic Pulmonary Fibrosis (IPF) is a debilitating and fatal lung disease characterized by the excessive formation of scar tissue and decline of lung function. Despite extensive research, only two FDA-approved drugs exist for IPF, with limited efficacy and relevant side effects. Thus, there is an urgent need for new effective therapies, whose discovery strongly relies on IPF animal models. Despite some limitations, the Bleomycin (BLM)-induced lung fibrosis mouse model is widely used for antifibrotic drug discovery and for investigating disease pathogenesis. The initial acute inflammation triggered by BLM instillation and the spontaneous fibrosis resolution that occurs after 3 weeks are the major drawbacks of this system. In the present study, we applied micro-CT technology to a longer-lasting, triple BLM administration fibrosis mouse model to define the best time-window for Nintedanib (NINT) treatment. Two different treatment regimens were examined, with a daily NINT administration from day 7 to 28 (NINT 7-28), and from day 14 to 28 (NINT 14-28). For the first time, we automatically derived both morphological and functional readouts from longitudinal micro-CT. NINT 14-28 showed significant effects on morphological parameters after just 1 week of treatment, while no modulations of these biomarkers were observed during the preceding 7-14-days period, likely due to persistent inflammation. Micro-CT morphological data evaluated on day 28 were confirmed by lung histology and bronchoalveolar lavage fluid (BALF) cells; Once again, the NINT 7-21 regimen did not provide substantial benefits over the NINT 14-28. Interestingly, both NINT treatments failed to improve micro-CT-derived functional parameters. Altogether, our findings support the need for optimized protocols in preclinical studies to expedite the drug discovery process for antifibrotic agents. This study represents a significant advancement in pulmonary fibrosis animal modeling and antifibrotic treatment understanding, with the potential for improved translatability through the concurrent structural-functional analysis offered by longitudinal micro-CT.

Expression of HOXB7 in the Lung of Patients with Idiopathic Pulmonary Fibrosis: A Proof-of-Concept Study.

BACKGROUND: The molecular pathways involved in the onset and progression of idiopathic pulmonary fibrosis (IPF) still need to be fully clarified as some are shared with lung cancer development. HOXB7, a member of the homeobox (Hox) gene family, has been found involved in various cancers. METHODS: Immunohistochemical (IHC) analysis was run on lung tissue samples from surgical lung biopsy (SLB) of 19 patients with IPF, retrospectively selected from the IPF database of the University Hospital of Modena. HOXB7 expression was analyzed and compared with that of five patients with no evidence of pulmonary fibrosis as controls. RESULTS: The semi-quantitative analysis of IHC showed that HOXB7 protein expression was higher in IPF patients compared to controls (difference between means = 6.2 ± 2.37, p = 0.0157). Further, HOXB7 expression was higher in IPF patients with a higher extent of fibrosis (50-75%)-measured with high-resolution computer tomography-compared to those with a lower extent (0-25%) (difference between means = 25.74 ± 6.72, p = 0.004). CONCLUSIONS: The expression of HOXB7 is higher in the lung of IPF patients compared to controls, and was represented in different cellular compartments within the lung niche. Further investigations are needed to clarify its role in the pathogenesis and progression of IPF.

Lung Fibrosis Is Linked to Increased Endothelial Cell Activation and Dysfunctional Vascular Barrier Integrity.

Pulmonary fibrosis can be a fatal disease characterized by progressive lung scarring. It is still poorly understood how the pulmonary endothelium is involved in the disease pathogenesis. Differences of the pulmonary vasculature between patients and donors were analysed using transmission electron microscopy, immunohistochemistry and single-cell-RNA-sequencing. Vascular barrier resistance, endothelial-immune cell adhesion, and sensitivity to an inflammatory milieu were studied in-vitro. Integrity and activation markers were measured by ELISA in human plasma. Transmission electron microscopy demonstrated abnormally swollen endothelial cells in fibrotic lungs as compared to donors. A more intense CD31 and vWF and patchy VE-Cadherin staining in fibrotic lungs supported the presence of a dysregulated endothelium. Integrity markers CD31, VE-Cadherin, Thrombomodulin and VEGFR-2 and activation marker von-Willebrand-Factor gene expression was increased in different endothelial subpopulations (e.g. arterial, venous, gCap, aCap) in pulmonary fibrosis. This was associated with a heightened sensitivity of fibrotic endothelial cells to TNF-α or IFN-γ and elevated immune cell adhesion. The barrier strength was overall reduced in endothelial cells from fibrotic lungs. vWF and IL-8 were increased in the plasma of patients, while VE-Cadherin, Thrombomodulin and VEGFR-2 were decreased. VE-Cadherin staining was also patchy in biopsy tissue and was decreased in plasma samples of PF patients six months after the initial diagnosis. Our data demonstrate highly abnormal endothelial cells in PF. The vascular compartment is characterized by hyper-activation and increased immune cell adhesion, as well as dysfunctional endothelial barrier function. Re-establishing endothelial cell homeostasis and function might represent a new therapeutic option for fibrotic lung diseases.

The potential ameliorating effect of vitamin E on bleomycin - induced lung fibrosis in adult albino rats.

Lung fibrosis is a critical interstitial lung disease with poor prognosis. There is an urgent need to develop a proper and cost-effective therapeutic modality that can reverse and/or ameliorate lung fibrosis. Vitamin E is one of the widely investigated dietary antioxidants which has been linked to improvement of many health problems. The current study was conducted to evaluate the possible roles of vitamin E in prevention and treatment of bleomycin (BLM) induced lung fibrosis. Physiological, anatomical, histopathological and immunohistochemical studies were done to assess and compare between the structure and function of the lung tissue in lung fibrosis model, early and late treated groups with vitamin E. Furthermore, measurement of transforming growth factor-ß(TGF-ß), E-cadherin, Smad-3, BAX, BCL2, malondialdehyde (MDA), and superoxide dismutase (SOD) were done. The study revealed that administration of vitamin E helped to improve signs of lung fibrosis, as reflected by amelioration of structure and functions of lungs as well as the decrease in TGF-ß levels and inhibition of α-SMA/collagen I profibrotic pathway. These findings highlight the importance of administration of vitamin E as a prophylactic agent prior to BLM therapy and as an adjuvant treatment in cases of lung fibrosis.

Ziziphus spina-christi L. extract attenuates bleomycin-induced lung fibrosis in mice via regulating TGF-ß1/SMAD pathway: LC-MS/MS Metabolic profiling, chemical composition, and histology studies.

Ancient Egyptians (including Bedouins and Nubians) have long utilized Ziziphus spina-christi (L.), a traditional Arabian medicinal herb, to alleviate swellings and inflammatory disorders. It is also mentioned in Christian and Muslim traditions. Ziziphus spina-christi L. (Family: Rhamnaceae) is a plentiful source of polyphenols, revealing free radical scavenging, antioxidant, metal chelating, cytotoxic, and anti-inflammatory activities. Herein, different classes of the existing bioactive metabolites in Z. spina-christi L. were detected using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the first time. The study also aimed to assess the anti-inflammatory and antifibrotic properties of Z. spina-christi L. extract against bleomycin-induced lung fibrosis in an experimental mouse model. 32 male Swiss Albino mice were assigned into 4 groups; the first and second were the normal control group and the bleomycin positive control (single 2.5 U/kg bleomycin intratracheal dose). The third and fourth groups received 100 and 200 mg/kg/day Z. spina-christi L. extract orally for 3 weeks, 2 weeks before bleomycin, and 1 week after. The bioactive metabolites in Z. spina-christi L. extract were identified as phenolic acids, catechins, flavonoids, chalcones, stilbenes, triterpenoid acids, saponins, and sterols. The contents of total phenolic compounds and flavonoids were found to be 196.62 mg GAE/gm and 33.29 mg QE/gm, respectively. In the experimental study, histopathological examination revealed that lung fibrosis was attenuated in both Z. spina-christi L.- treated groups. Z. spina-christi L. extract downregulated the expression of nuclear factor kappa B (NF-κB) p65 and decreased levels of the inflammatory markers tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and c-Jun N-terminal kinase (JNK) in lung tissue. Z. spina-christi L. also downregulated the expression of the fibrotic parameters collagen-1, alpha-smooth muscle actin (α-SMA), transforming growth factor-beta 1 (TGF-ß1), matrix metalloproteinase-9 (MMP-9) and SMAD3, with upregulation of the antifibrotic SMAD7 in lung tissue. Overall, the present study suggests a potential protective effect of Z. spina-christi L. extract against bleomycin-induced lung fibrosis through regulation of the TGF-ß1/SMAD pathway.