Regorafenib-Attenuated, Bleomycin-Induced Pulmonary Fibrosis by Inhibiting the TGF-β1 Signaling Pathway

Circadian clock regulation of myofibroblast fate

Fibrosis-related disorders represent an increasing medical and economic burden on a worldwide scale, accounting for one-third of all disease-related deaths with limited therapeutic options. As central mediators in fibrosis development, myofibroblasts have been gaining increasing attention in the last 20 years as potential targets for fibrosis attenuation and reversal. While various aspects of myofibroblast physiology have been proposed as treatment targets, many of these approaches have shown limited long-term efficacy so far. However, ongoing research is uncovering new potential strategies for targeting myofibroblast activity, offering hope for more effective treatments in the future. The circadian molecular clock is a feature of almost every cell in the human body that dictates the rhythmic nature of various aspects of human physiology and behavior in response to changes in the surrounding environment. The dysregulation of these rhythms with aging is considered to be one of the underlying reasons behind the development of multiple aging-related chronic disorders, with fibrotic tissue scarring being a common pathological complication among the majority of them. Myofibroblast dysregulation due to skewed circadian clockwork might significantly contribute to fibrotic scar persistence. In the current review, we highlight the role of the circadian clock in the context of myofibroblast activation and deactivation and examine its dysregulation as a driver of fibrogenesis.

Regorafenib exerts an inhibitory effect on the proliferation of human lung fibroblasts by reducing the production of several cytokines in vitro study

BACKGROUND

Pulmonary fibrosis is a disease that leads to respiratory failure and death. There has been little progress in therapeutic strategies for pulmonary fibrosis. There have been several reports on the cytokines associated with pulmonary fibrosis, including IL-6 and TGF-β1. Angiogenesis is one of the most important phenomena in the pathogenesis of pulmonary fibrosis. Previously, we reported the preventive effects of thalidomide against pulmonary fibrosis via the inhibition of neovascularization by angiogenic factors such as VEGF. Regorafenib is a multikinase inhibitor, which inhibits tyrosine kinase receptors such as VEGFR1-3 and TIE2. In the clinical setting, regorafenib has been widely used for anti-cancer therapy for metastatic colorectal cancer. In this study, we examined the preventive effects of regorafenib against pulmonary fibrosis.

METHODS

We investigated whether regorafenib had an inhibitory effect on the proliferation, viability, and production of several cytokines in lung fibroblasts.

RESULTS

We demonstrated an inhibitory effect of regorafenib on the proliferation and viability of lung fibroblasts. Moreover, regorafenib reduced the production of several cytokines associated with the pathogenesis of pulmonary fibrosis, including IL-6, VEGF and TGF- β1, and collagen synthesis from lung fibroblasts.

CONCLUSIONS

These data suggest that regorafenib may have potential clinical applications in the prevention of pulmonary fibrosis.

Regorafenib as a potential drug for severe COVID-19: inhibition of inflammasome activation in mice

SARS-CoV-2 infection can lead to severe COVID-19, particularly in elderly individuals and those with compromised immunity. Cellular senescence has been implicated as a key pathogenic mechanism. This study investigated the therapeutic potential of regorafenib, a previously characterized senomorphic drug, for severe COVID-19. SARS-CoV-2 virus-infected K18-hACE2 mice, overexpressing the human ACE2 receptor, exhibited 100% mortality by 10 days post infection. Regorafenib treatment significantly improved survival rates, approximately 43% remaining alive. Mechanistically, regorafenib effectively suppressed type I and II interferon and cytokine signaling. Notably, regorafenib inhibited NLR family pyrin domain containing 3 (NLRP3) inflammasome activation, a key driver of the cytokine storm associated with severe COVID-19. Our findings elucidate the molecular mechanisms underlying therapeutic effects of regorafenib and suggest its potential use as a promising treatment option for severe COVID-19.

Identifying novel therapeutic targets in cystic fibrosis through advanced single-cell transcriptomics analysis

BACKGROUND

Lung disease remains a leading cause of morbidity and mortality in individuals with cystic fibrosis (CF). Despite significant advances, the complex molecular mechanisms underlying CF-related airway pathology are not fully understood. Building upon previous single-cell transcriptomics studies in CF patients and healthy controls, this study employs enhanced analytical methodologies to deepen our understanding of CF-associated gene expression.

METHODS

We employed advanced single-cell transcriptomics techniques, integrating data from multiple sources and implementing rigorous normalization and mapping strategies using a comprehensive lung reference panel. These sophisticated methods were designed to enhance the accuracy and depth of our analysis, with a focus on elucidating differential gene expression and characterizing co-expression network dynamics associated with cystic fibrosis (CF).

RESULTS

Our analysis uncovered novel genes and regulatory networks that had not been previously associated with CF airway disease. These findings highlight new potential therapeutic targets that could be exploited to develop more effective interventions for managing CF-related lung conditions.

CONCLUSION

This study provides critical insights into the molecular landscape of CF airway disease, offering new avenues for targeted therapeutic strategies. By identifying key genes and networks involved in CF pathogenesis, our research contributes to the broader efforts to improve the prognosis and quality of life for patients with CF. These discoveries pave the way for future studies aimed at translating these findings into clinical practice.

Carbon monoxide attenuates cellular senescence-mediated pulmonary fibrosis via modulating p53/PAI-1 pathway

PURPOSE

Idiopathic pulmonary fibrosis (IPF) is a fatal progressive condition often requiring lung transplantation. Accelerated senescence of type II alveolar epithelial cells (AECII) plays a crucial role in pulmonary fibrosis progression through the secretion of the senescence-associated secretory phenotype (SASP). Low-dose carbon monoxide (CO) possesses anti-inflammatory, anti-oxidative, and anti-aging properties. This study aims to explore the preventive effects of CO-releasing molecule 2 (CORM2) in a bleomycin-induced pulmonary fibrosis model.

METHODS

We established an pulmonary fibrosis model in C57BL/6J mice and evaluated the impact of CORM2 on fibrosis pathology using Masson's trichrome staining, fluorescence staining, and pulmonary function tests. Fibrogenic marker expression and SASP secretion in tissues and AECII cells were analyzed using qRT-PCR, Western blot, and ELISA assays both in vivo and in vitro. Additionally, we investigated DNA damage and cellular senescence through immunofluorescence and SA-β-gal staining.

RESULTS

CORM2 showed a preventive effect on bleomycin-induced lung fibrosis by improving pulmonary function and reducing the expression of fibrosis-related genes, such as TGF-β, α-SMA, Collagen I/III. CORM2 decreased the DNA damage response by inhibiting γ-H2AX, p53, and p21. We identified PAI-1 as a new target gene that was downregulated by CORM2, and which was associated with cellular senescence and fibrosis. CORM2 effectively inhibited cellular senescence and delayed EMT occurrence in AECII cells.

CONCLUSION

Our study highlights the potential of CORM2 in preventing DNA damage-induced cellular senescence in bleomycin-induced pulmonary fibrosis through modulation of the p53/PAI-1 signaling pathway. These findings underscore the promising prospects of CORM2 in targeting cellular senescence and the p53/PAI-1 pathway as a potential preventive strategy for IPF.

Unagi: Deep Generative Model for Deciphering Cellular Dynamics and In-Silico Drug Discovery in Complex Diseases

Human diseases are characterized by intricate cellular dynamics. Single-cell sequencing provides critical insights, yet a persistent gap remains in computational tools for detailed disease progression analysis and targeted in-silico drug interventions. Here, we introduce UNAGI, a deep generative neural network tailored to analyze time-series single-cell transcriptomic data. This tool captures the complex cellular dynamics underlying disease progression, enhancing drug perturbation modeling and discovery. When applied to a dataset from patients with Idiopathic Pulmonary Fibrosis (IPF), UNAGI learns disease-informed cell embeddings that sharpen our understanding of disease progression, leading to the identification of potential therapeutic drug candidates. Validation via proteomics reveals the accuracy of UNAGI's cellular dynamics analyses, and the use of the Fibrotic Cocktail treated human Precision-cut Lung Slices confirms UNAGI's predictions that Nifedipine, an antihypertensive drug, may have antifibrotic effects on human tissues. UNAGI's versatility extends to other diseases, including a COVID dataset, demonstrating adaptability and confirming its broader applicability in decoding complex cellular dynamics beyond IPF, amplifying its utility in the quest for therapeutic solutions across diverse pathological landscapes.

A systematic review of the research progress of traditional Chinese medicine against pulmonary fibrosis: from a pharmacological perspective

Pulmonary fibrosis is a chronic progressive interstitial lung disease caused by a variety of etiologies. The disease can eventually lead to irreversible damage to the lung tissue structure, severely affecting respiratory function and posing a serious threat to human health. Currently, glucocorticoids and immunosuppressants are the main drugs used in the clinical treatment of pulmonary fibrosis, but their efficacy is limited and they can cause serious adverse effects. Traditional Chinese medicines have important research value and potential for clinical application in anti-pulmonary fibrosis. In recent years, more and more scientific researches have been conducted on the use of traditional Chinese medicine to improve or reduce pulmonary fibrosis, and some important breakthroughs have been made. This review paper systematically summarized the research progress of pharmacological mechanism of traditional Chinese medicines and their active compounds in improving or reducing pulmonary fibrosis. We conducted a systematic search in several main scientific databases, including PubMed, Web of Science, and Google Scholar, using keywords such as idiopathic pulmonary fibrosis, pulmonary fibrosis, interstitial pneumonia, natural products, herbal medicine, and therapeutic methods. Ultimately, 252 articles were included and systematically evaluated in this analysis. The anti-fibrotic mechanisms of these traditional Chinese medicine studies can be roughly categorized into 5 main aspects, including inhibition of epithelial-mesenchymal transition, anti-inflammatory and antioxidant effects, improvement of extracellular matrix deposition, mediation of apoptosis and autophagy, and inhibition of endoplasmic reticulum stress. The purpose of this article is to provide pharmaceutical researchers with information on the progress of scientific research on improving or reducing Pulmonary fibrosis with traditional Chinese medicine, and to provide reference for further pharmacological research.

Promising small molecule anti-fibrotic agents: Newly developed or repositioned drugs targeting myofibroblast transdifferentiation

Fibrosis occurs in all organs and tissues except the brain, and its progression leads to dysfunction of affected organs. Fibrosis-induced organ dysfunction results from the loss of elasticity, strength, and functionality of tissues due to the extracellular matrix secreted by myofibroblasts that express smooth muscle-type actin as a marker. Myofibroblasts, which play a major role in fibrosis, were once thought to originate exclusively from activated fibroblasts; however, it is now clear that myofibroblasts are diverse in origin, from epithelial cells, endothelial cells, adipocytes, macrophages, and other cells. Fibrosis of vital organs, such as the heart, lungs, kidneys, and liver, is a serious chronic disease that ultimately leads to death. Currently, anti-cancer drugs have made remarkable progress, as evidenced by the development of many molecular-targeted drugs, and are making a significant contribution to improving the prognosis of cancer treatment. However, the development of anti-fibrotic agents, which also play an important role in prognosis, has lagged. In this review, the current knowledge regarding myofibroblasts is summarized, with particular attention given to their origin and transdifferentiation signaling pathways (e.g., TGF-β, Wnt/β-catenin, YAP/TAZ and AMPK signaling pathways). The development of new small molecule anti-fibrotic agents and the repositioning of existing drugs targeting myofibroblast transdifferentiation are discussed.

Defining regorafenib as a senomorphic drug: therapeutic potential in the age-related lung disease emphysema

Senescence, a hallmark of aging, is a factor in age-related diseases (ARDs). Therefore, targeting senescence is widely regarded as a practicable method for modulating the effects of aging and ARDs. Here, we report the identification of regorafenib, an inhibitor of multiple receptor tyrosine kinases, as a senescence-attenuating drug. We identified regorafenib by screening an FDA-approved drug library. Treatment with regorafenib at a sublethal dose resulted in effective attenuation of the phenotypes of βPIX knockdown- and doxorubicin-induced senescence and replicative senescence in IMR-90 cells; cell cycle arrest, and increased SA-β-Gal staining and senescence-associated secretory phenotypes, particularly increasing the secretion of interleukin 6 (IL-6) and IL-8. Consistent with this result, slower progression of βPIX depletion-induced senescence was observed in the lungs of mice after treatment with regorafenib. Mechanistically, the results of proteomics analysis in diverse types of senescence indicated that growth differentiation factor 15 and plasminogen activator inhibitor-1 are shared targets of regorafenib. Analysis of arrays for phospho-receptors and kinases identified several receptor tyrosine kinases, including platelet-derived growth factor receptor α and discoidin domain receptor 2, as additional targets of regorafenib and revealed AKT/mTOR, ERK/RSK, and JAK/STAT3 signaling as the major effector pathways. Finally, treatment with regorafenib resulted in attenuation of senescence and amelioration of porcine pancreatic elastase-induced emphysema in mice. Based on these results, regorafenib can be defined as a novel senomorphic drug, suggesting its therapeutic potential in pulmonary emphysema.

Comparing species-different responses in pulmonary fibrosis research: Current understanding of in vitro lung cell models and nanomaterials

Pulmonary fibrosis (PF) is a chronic, irreversible lung disease that is typically fatal and characterized by an abnormal fibrotic response. As a result, vast areas of the lungs are gradually affected, and gas exchange is impaired, making it one of the world's leading causes of death. This can be attributed to a lack of understanding of the onset and progression of the disease, as well as a poor understanding of the mechanism of adverse responses to various factors, such as exposure to allergens, nanomaterials, environmental pollutants, etc. So far, the most frequently used preclinical evaluation paradigm for PF is still animal testing. Nonetheless, there is an urgent need to understand the factors that induce PF and find novel therapeutic targets for PF in humans. In this regard, robust and realistic in vitro fibrosis models are required to understand the mechanism of adverse responses. Over the years, several in vitro and ex vivo models have been developed with the goal of mimicking the biological barriers of the lung as closely as possible. This review summarizes recent progress towards the development of experimental models suitable for predicting fibrotic responses, with an emphasis on cell culture methods, nanomaterials, and a comparison of results from studies using cells from various species.

Inhibitory Effects of 3-Cyclopropylmethoxy-4-(difluoromethoxy) Benzoic Acid on TGF-β1-Induced Epithelial-Mesenchymal Transformation of In Vitro and Bleomycin-Induced Pulmonary Fibrosis In Vivo

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease characterized by lung inflammation and excessive deposition of extracellular matrix components. Transforming growth factor-β1 (TGF-β1) induced epithelial-mesenchymal transformation of type 2 lung epithelial cells leads to excessive extracellular matrix deposition, which plays an important role in fibrosis. Our objective was to evaluate the effects of 3-cyclopropylmethoxy-4-(difluoromethoxy) benzoic acid (DGM) on pulmonary fibrosis and aimed to determine whether EMT plays a key role in the pathogenesis of pulmonary fibrosis and whether EMT can be used as a therapeutic target for DGM therapy to reduce IPF. Firstly, stimulation of in vitro cultured A549 cells to construct EMTs with TGF-β1. DGM treatment inhibited the expression of proteins such as α-SMA, vimentin, and collagen Ⅰ and increased the expression of E-cadherin. Accordingly, Smad2/3 phosphorylation levels were significantly reduced by DGM treatment. Secondly, models of tracheal instillation of bleomycin and DGM were used to treat rats to demonstrate their therapeutic effects, such as improving lung function, reducing lung inflammation and fibrosis, reducing collagen deposition, and reducing the expression of E-cadherin. In conclusion, DGM attenuates TGF-β1-induced EMT in A549 cells and bleomycin-induced pulmonary fibrosis in rats.

Antifibrotic mechanism of avitinib in bleomycin-induced pulmonary fibrosis in mice

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease characterized by alveolar epithelial cell injury and lung fibroblast overactivation. At present, only two drugs are approved by the FDA for the treatment of IPF, including the synthetic pyridinone drug, pirfenidone, and the tyrosine kinase inhibitor, nintedanib. Avitinib (AVB) is a novel oral and potent third-generation tyrosine kinase inhibitor for treating non-small cell lung cancer (NSCLC). However, the role of avitinib in pulmonary fibrosis has not yet been established. In the present study, we used in vivo and in vitro models to evaluate the role of avitinib in pulmonary fibrosis. In vivo experiments first verified that avitinib significantly alleviated bleomycin-induced pulmonary fibrosis in mice. Further in vitro molecular studies indicated that avitinib inhibited myofibroblast activation, migration and extracellular matrix (ECM) production in NIH-3T3 cells, mainly by inhibiting the TGF-β1/Smad3 signalling pathways. The cellular experiments also indicated that avitinib improved alveolar epithelial cell injury in A549 cells. In conclusion, the present findings demonstrated that avitinib attenuates bleomycin-induced pulmonary fibrosis in mice by inhibiting alveolar epithelial cell injury and myofibroblast activation.

2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside ameliorates bleomycin-induced pulmonary fibrosis via regulating pro-fibrotic signaling pathways

2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-Glucoside (THSG) is the main active ingredient extracted from Polygonum multiflorum Thunb. (PMT), which has been reported to possess extensive pharmacological properties. Nevertheless, the exact role of THSG in pulmonary fibrosis has not been demonstrated yet. The main purpose of this study was to investigate the protective effect of THSG against bleomycin (BLM)-induced lung fibrosis in a murine model, and explore the underlying mechanisms of THSG in transforming growth factor-beta 1 (TGF-β1)-induced fibrogenesis using MRC-5 human lung fibroblast cells. We found that THSG significantly attenuated lung injury by reducing fibrosis and extracellular matrix deposition. THSG treatment significantly downregulated the expression levels of TGF-β1, fibronectin, α-SMA, CTGF, and TGFBR2, however, upregulated the expression levels of antioxidants (SOD-1 and catalase) and LC3B in the lungs of BLM-treated mice. THSG treatment decreased the expression levels of fibronectin, α-SMA, and CTGF in TGF-β1-stimulated MRC-5 cells. Conversely, THSG increased the expression levels of SOD-1 and catalase. Furthermore, treatment of THSG profoundly reduced the TGF-β1-induced generation of reactive oxygen species (ROS). In addition, THSG restored TGF-β1-induced impaired autophagy, accompany by increasing the protein levels of LC3B-II and Beclin 1. Mechanism study indicated that THSG significantly reduced TGF-β1-induced increase of TGFBR2 expression and phosphorylation of Smad2/3, Akt, mTOR, and ERK1/2 in MRC-5 cells. These findings suggest that THSG may be considered as an anti-fibrotic drug for the treatment of pulmonary fibrosis.

Re-Du-Ning injection ameliorates radiation-induced pneumonitis and fibrosis by inhibiting AIM2 inflammasome and epithelial-mesenchymal transition

BACKGROUND

Radiation-induced lung injury (RILI) is a common side effect in chest radiotherapy patients, and there is no good medicine to treat it. Re-Du-Ning (RDN) injection is a traditional Chinese medicine that is clinically used to treat upper respiratory tract infections and acute bronchitis. RDN has the advantage of high safety and mild side effects. The mechanism of most traditional Chinese medicine preparations is unknown.

PURPOSE

To illustrate the mechanisms of RDN for the treatment of RILI.

METHODS

Female C57BL/6 mice were used to establish a RILI model via irradiation, and RDN injection was intraperitoneally administered at doses of 5, 10, and 20 ml/kg. The cytokines were measured by ELISA and qPCR. The data related to Absent in melanoma 2 (AIM2) inflammasome were analyzed via ELISA and a network pharmacological approach. In addition, the data related to epithelial-mesenchymal transition (EMT) were analyzed via immunofluorescence, Western blotting, and a network pharmacological approach.

RESULTS

RDN robustly alleviated RILI. Meanwhile, RDN downregulated inflammatory cells' infiltration and the expression of pro-inflammatory cytokines, such as IL-1β, IL-6, and TNF-α. Next, the potential molecular mechanisms of RDN were predicted through network pharmacology analysis. RDN may ameliorate radiation pneumonitis (RP) by inhibiting AIM2-mediated pyroptosis. Moreover, RDN treatment inhibited EMT and phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT) pathway. The active compounds from Lonicera japonica Thunb. decreased the phosphorylation of Akt.

CONCLUSION

These findings demonstrate that RDN, as a traditional Chinese medicine preparation, will be a candidate drug for treating RILI.

Anti-PD-L1 antibody alleviates pulmonary fibrosis by inducing autophagy via inhibition of the PI3K/Akt/mTOR pathway

Pulmonary fibrosis is a fatal lung disease for which no effective treatment is available. Previous studies have shown that the expression of programmed cell death-Ligand (PD-L1) is significantly increased in pulmonary fibrosis, and that this is related to the occurrence of this disease. However, the underlying mechanism is not clear. To clarify the efficacy and mechanism of an anti-PD-L1 monoclonal antibody (anti-PD-L1 mAb) as a treatment for pulmonary fibrosis, we conducted histopathological, molecular, and functional analyses in a mouse model of bleomycin-induced pulmonary fibrosis and a cell model of fibrosis induced by transforming growth factor-beta 1 (TGF-β1). Our results indicate that PD-L1 is highly expressed in the lung fibrosis model. The anti-PD-L1 mAb significantly alleviated bleomycin-induced lung structural disorders and collagen deposition in mice and inhibited the proliferation, migration, activation and extracellular matrix deposition of TGF-β1-induced lung fibroblasts. Interestingly, the anti-PD-L1 mAb could also alleviate the autophagy impairment observed in pulmonary fibrosis. The potential mechanism is through the downregulation of the PI3K/Akt/mTOR signaling pathway. Our study provides evidence of the crucial ability of anti-PD-L1 mAbs to activate autophagy in the context of pulmonary fibrosis, providing a new strategy for the treatment of this disease.

Factors Determining Plasticity of Responses to Drugs

The plasticity of responses to drugs is an ever-present confounding factor for all aspects of pharmacology, influencing drug discovery and development, clinical use and the expectations of the patient. As an introduction to this Special Issue of the journal IJMS on pharmacological plasticity, we address the various levels at which plasticity appears and how such variability can be controlled, describing the ways in which drug responses can be affected with examples. The various levels include the molecular structures of drugs and their receptors, expression of genes for drug receptors and enzymes involved in metabolism, plasticity of cells targeted by drugs, tissues and clinical variables affected by whole body processes, changes in geography and the environment, and the influence of time and duration of changes. The article provides a rarely considered bird’s eye view of the problem and is intended to emphasize the need for increased awareness of pharmacological plasticity and to encourage further debate.

Effect of Regorafenib on P2X7 Receptor Expression and Different Oncogenic Signaling Pathways in a Human Breast Cancer Cell Line: A Potential of New Insight of the Antitumor Effects of Regorafenib

BACKGROUND

Breast cancer is the most common malignancy in women worldwide. P2X7 is a transmembrane receptor expressed in breast cancer and activated by the ATP tumor microenvironment, driving cell proliferation, angiogenesis, and metastasis via different signaling pathways. The role of the P2X7 receptor, hypoxia, and autophagy in regulating tumor progression is controversial. The multikinase inhibitor regorafenib prevents the activation of numerous kinases involved in angiogenesis, proliferation, and metastasis. The present study aimed to evaluate the modulatory effect of regorafenib on the hypoxia/angiogenesis/P2X7R/autophagy axis on the MCF7 breast cancer cell line and its impact on different signaling pathways involved in breast cancer pathogenesis.

METHODS

The levels of VEGF, VEGFR, PI3K, NF-κB, HIF-1α, and LC3-II were analyzed using ELISA, and caspase-3 activity was also assessed colorimetrically. Phosphorylated (p)-p38 MAPK and purinergic ligand-gated ion channel 7 (P2X7) receptor protein expression levels were analyzed via Western blotting. Reverse transcription-quantitative PCR was used to determine the mRNA expression levels of Beclin 1 (BECN1), LC3-II, and sequestosome 1 (p62).

RESULTS

Regorafenib reduced MCF7 cell viability in a dose-dependent manner. Furthermore, regorafenib significantly reduced levels of PI3K, NF-κB, VEGF, VEGFR, P2X7 receptor, and p-p38 MAPK protein expression, and markedly reduced p62 mRNA expression levels. However, regorafenib significantly increased caspase-3 activity, as well as BECN1 and LC3-II mRNA expression levels.

CONCLUSIONS

Regorafenib was demonstrated to possibly exhibit antitumor activity on the breast cancer cell line via modulation of the P2X7/HIF-1α/VEGF, P2X7/P38, P2X7/ERK/NF-κB, and P2X7/beclin 1 pathways.

Atractylodin Suppresses TGF-β-Mediated Epithelial-Mesenchymal Transition in Alveolar Epithelial Cells and Attenuates Bleomycin-Induced Pulmonary Fibrosis in Mice

Idiopathic pulmonary fibrosis (IPF) is characterized by fibrotic change in alveolar epithelial cells and leads to the irreversible deterioration of pulmonary function. Transforming growth factor-beta 1 (TGF-β1)-induced epithelial-mesenchymal transition (EMT) in type 2 lung epithelial cells contributes to excessive collagen deposition and plays an important role in IPF. Atractylodin (ATL) is a kind of herbal medicine that has been proven to protect intestinal inflammation and attenuate acute lung injury. Our study aimed to determine whether EMT played a crucial role in the pathogenesis of pulmonary fibrosis and whether EMT can be utilized as a therapeutic target by ATL treatment to mitigate IPF. To address this topic, we took two steps to investigate: 1. Utilization of anin vitro EMT model by treating alveolar epithelial cells (A549 cells) with TGF-β1 followed by ATL treatment for elucidating the underlying pathways, including Smad2/3 hyperphosphorylation, mitogen-activated protein kinase (MAPK) pathway overexpression, Snail and Slug upregulation, and loss of E-cadherin. Utilization of an in vivo lung injury model by treating bleomycin on mice followed by ATL treatment to demonstrate the therapeutic effectiveness, such as, less collagen deposition and lower E-cadherin expression. In conclusion, ATL attenuates TGF-β1-induced EMT in A549 cells and bleomycin-induced pulmonary fibrosis in mice.