Protective effect of rutin against bleomycin induced lung fibrosis: Involvement of TGF-β1/α-SMA/Col I and III pathway

Mimosa pudica L. extract ameliorates pulmonary fibrosis via modulation of MAPK signaling pathways and FOXO3 stabilization

ETHNOPHARMACOLOGICAL RELEVANCE

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing pulmonary disorder that has a poor prognosis and high mortality. Although there has been extensive effort to introduce several new anti-fibrotic agents in the past decade, IPF remains an incurable disease. Mimosa pudica L., an indigenous Vietnamese plant, has been empirically used to treat respiratory disorders. Nevertheless, the therapeutic effects of M. pudica (MP) on lung fibrosis and the mechanisms underlying those effects remain unclear.

AIM OF THE STUDY

This study investigated the protective effect of a crude ethanol extract of the above-ground parts of MP against pulmonary fibrogenesis.

MATERIALS AND METHODS

Inflammatory responses triggered by TNFα in structural lung cells were examined in normal human lung fibroblasts and A549 alveolar epithelial cells using Western blot analysis, reverse transcription-quantitative polymerase chain reaction assays, and immunocytochemistry. The epithelial-to-mesenchymal transition (EMT) was examined via cell morphology observations, F-actin fluorescent staining, gene and protein expression measurements, and a wound-healing assay. Anti-fibrotic assays including collagen release, differentiation, and measurements of fibrosis-related gene and protein expression levels were performed on TGFβ-stimulated human lung fibroblasts and lung fibroblasts derived from mice with fibrotic lungs. Finally, in vitro anti-fibrotic activities were validated using a mouse model of bleomycin-induced pulmonary fibrosis.

RESULTS

MP alleviated the inflammatory responses of A549 alveolar epithelial cells and lung fibroblasts, as revealed by inhibition of TNFα-induced chemotactic cytokine and chemokine expression, along with inactivation of the MAPK and NFκB signalling pathways. MP also partially reversed the TGFβ-promoted EMT via downregulation of mesenchymal markers in A549 cells. Importantly, MP decreased the expression levels of fibrosis-related genes/proteins including collagen I, fibronectin, and αSMA; moreover, it suppressed collagen secretion and prevented myofibroblast differentiation in lung fibroblasts. These effects were mediated by FOXO3 stabilization through suppression of TGFβ-induced ERK1/2 phosphorylation. MP consistently protected mice from the onset and progression of bleomycin-induced pulmonary fibrosis.

CONCLUSION

This study explored the multifaceted roles of MP in counteracting the pathobiological processes of lung fibrosis. The results suggest that further evaluation of MP could yield candidate therapies for IPF.

Novel therapeutic strategies and drugs for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease of unknown etiology. Currently, drugs used to treat IPF in clinical practice exhibit severe side effects and limitations. To address these issues, this paper discusses the therapeutic effects of preclinical targeted drugs (such as STAT3 and TGF-β/Smad pathway inhibitors, chitinase inhibitors, PI3K and phosphodiesterase inhibitors, etc.) and natural products on IPF. Through a summary of current research progress, it is found that natural products possess multitarget effects, stable therapeutic efficacy, low side effects, and nondrug dependence. Furthermore, we discuss the significant prospects of natural product molecules in combating fibrosis by influencing the immune system, expecting that current analytical data will aid in the development of new drugs or the investigation of active ingredients in natural products for potential IPF treatments in the future.

Therapeutic effects of flavonoids on pulmonary fibrosis: A preclinical meta-analysis

BACKGROUND

The efficacy of flavonoid supplementation in animal models of pulmonary fibrosis has been demonstrated.

PURPOSE

We conducted a systematic review and meta-analysis to evaluate the efficacy and underlying mechanisms of flavonoids in animal models of bleomycin-induced pulmonary fibrosis.

STUDY DESIGN

Relevant studies (n = 45) were identified from English- and Chinese-language databases from the inception of the database until October 2023.

METHODS

Methodological quality was evaluated using the SYRCLE risk of bias tool. Statistical analyses were conducted using RevMan 5.3 and Stata 17.0. Lung inflammation and fibrosis score were the primary outcome indicators.

RESULTS

Flavonoids can alleviate pathological changes in the lungs. The beneficial effects of flavonoids on pulmonary fibrosis likely relate to their inhibition of inflammatory responses, restoration of oxidative and antioxidant homeostasis, and regulation of fibroblast proliferation, migration, and activation by transforming growth factor β1/mothers against the decapentaplegic homologue/AMP-activated protein kinase (TGF-β1/Smad3/AMPK), inhibitor kappa B alpha/nuclear factor-kappa B (IκBα/NF-κB), phosphatidylinositol 3-kinase (PI3K)/AKT, interleukin 6/signal transducer/activator of transcription 3 (IL6/STAT3), and nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2-Keap1) pathways.

CONCLUSION

Flavonoids are potential candidate compounds for the prevention and treatment of pulmonary fibrosis. However, extensive preclinical research is necessary to confirm the antifibrotic properties of natural flavonoids.

CAV1 Protein Encapsulated in Mouse BMSC-Derived Extracellular Vesicles Alleviates Myocardial Fibrosis Following Myocardial Infarction by Blocking the TGF-β1/SMAD2/c-JUN Axis

Extracellular vesicles (EVs) derived from mouse bone marrow mesenchymal stem cells (mBMSCs) convey the CAV1 protein, influencing the TGF-β1/SMAD2/c-JUN pathway and thus the molecular mechanisms underlying myocardial fibrosis (MF) post-myocardial infarction (MI). Through various experimental methods, including transmission electron microscopy, Nanosight analysis, Western blot, ELISA, and qRT-PCR, we isolated, purified, and identified EVs originating from mBMSCs. Bioinformatics and experimental findings show a reduced expression of CAV1 in myocardial fibrosis tissue. Furthermore, our findings suggest that mBMSC-EVs can deliver CAV1 to cardiac fibroblasts (CFs) and that silencing CAV1 in mBMSC-EVs promotes CF fibrosis. In vivo studies further corroborated these findings. In conclusion, mBMSC-EVs mitigate myocardial fibrosis in MI mice by delivering the CAV1 protein, inhibiting the TGF-β1/SMAD2/c-JUN pathway.

Investigating rutin as a potential transforming growth factor-β type I receptor antagonist for the inhibition of bleomycin-induced lung fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic lung condition characterized by the abnormal regulation of extracellular matrix (ECM) and epithelial-mesenchymal transition (EMT). In this study, we investigated the potential of rutin, a natural flavonoid, in attenuating transforming growth factor-β (TGF-β)-induced ECM regulation and EMT through the inhibition of the TGF-β type I receptor (TβRI)-mediated suppressor of mothers against decapentaplegic (SMAD) signaling pathway. We found that non-toxic concentrations of rutin attenuated TGF-β-induced ECM-related genes, including fibronectin, elastin, collagen 1 type 1, and TGF-β, as well as myoblast differentiation from MRC-5 lung fibroblast cells accompanied by the downregulation of α-smooth muscle actin. Rutin also inhibited TGF-β-induced EMT processes, such as wound healing, migration, and invasion by regulating EMT-related gene expression. Additionally, rutin attenuated bleomycin-induced lung fibrosis in mice, thus providing a potential therapeutic option for IPF. The molecular docking analyses in this study predict that rutin occludes the active site of TβRI and inhibits SMAD-mediated fibrotic signaling pathways in lung fibrosis. These findings highlight the potential of rutin as a promising anti-fibrotic prodrug for lung fibrosis and other TGF-β-induced fibrotic and cancer-related diseases; however, further studies are required to validate its safety and effectiveness in other experimental models.

L-arginine mitigates bleomycin-induced pulmonary fibrosis in rats through regulation of HO-1/PPAR-γ/β-catenin axis

Pulmonary fibrosis is a chronic and progressively deteriorating lung condition that can be replicated in laboratory animals by administering bleomycin, a chemotherapeutic antibiotic known for its lung fibrosis-inducing side effects. L-arginine, a semi-essential amino acid, is recognized for its diverse biological functions, including its potential to counteract fibrosis. This study aimed to evaluate the antifibrotic properties of L-arginine on bleomycin-induced pulmonary fibrosis in rats. The administration of a single intratracheal dose of bleomycin resulted in visible and microscopic damage to lung tissues, an uptick in oxidative stress markers, and an elevation in inflammatory, apoptotic, and fibrotic indicators. A seven-day treatment with L-arginine post-bleomycin exposure markedly improved the gross and histological architecture of the lungs, prevented the rise of malondialdehyde and carbonyl content, and enhanced total antioxidant capacity alongside the activities of antioxidant enzymes. Also, L-arginine attenuated the expression of the pro-fibrotic factors, transforming growth factor-β and lactate dehydrogenase in bronchoalveolar lavage fluid. In the lung tissue, L-arginine reduced collagen deposition, hydroxyproline concentration, and mucus production, along with decreasing expression of α-smooth muscle actin, tumor necrosis factor-α, caspase-3, matrix metalloproteinase-9, and β-catenin. Moreover, it boosted levels of nitric oxide and upregulated the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ), heme oxygenase-1 (HO-1), and E-cadherin and downregulating the expression of β-catenin. These findings suggest that L-arginine has preventive activities against bleomycin-induced pulmonary fibrosis. This effect can be attributed to the increased production of nitric oxide, which modulates the HO-1/PPAR-γ/β-catenin axis.

Modified Qing-Zao-Jiu-Fei decoction attenuated pulmonary fibrosis induced by bleomycin in rats via modulating Nrf2/NF-κB and MAPKs pathways

BACKGROUND

Qing-Zao-Jiu-Fei Decoction (QZJFD) is a famous herbal formula commonly prescribed for the treatment of lung-related diseases in the ancient and modern times. Trichosanthis Fructus (TF) and Fritillariae Thunbergii Bulbus (FTB) are widely used for treatment of cough and pulmonary disease. In order to identify a more effective formula for treatment of pulmonary fibrosis, we intend to add TF and FTB in QZJFD to form a modified QZJFD (MQZJFD). In this study, we aims to explore MQZJFD as an innovative therapeutic agent for pulmonary fibrosis using bleomycin (BLM)-treated rats and to unravel the underlying molecular mechanisms.

METHODS

BLM was given to SD rats by intra-tracheal administration of a single dose of BLM (5 mg/kg). QZJFD (3 g/kg) and MQZJFD (1, 2 and 4 g/kg) was given intragastrically daily to rats for 14 days (from day 15 to 28) after BLM administration for 14 consecutive days.

RESULTS

MQZJFD was found to contain 0.29% of amygdalin, 0.020% of lutin, 0.077% of glycyrrhizic acid and 0.047% of chlorogenic acid. BLM treatment could induce collagen deposition in the lung tissues of rats, indicating that the pulmonary fibrosis rat model had been successfully established. MQZJFD have better effects than the original QZJFD in reducing the pulmonary structure damage and collagen deposition of rat lung fibrosis induced by BLM. MQZJFD could reduce the hydroxyproline content in lung tissues of BLM-treated rats. The biomarkers of fibrosis such as matrix metalloproteinase 9 (MMP9), collagen I and α-smooth muscle actin (α-SMA) were remarkably reduced after treatment with MQZJFD. MQZJFD also have anti-oxidant stress effects by inhibiting the level of malondialdehyde (MDA), but enhancing the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the level of glutathione (GSH) in the lung tissues of BLM-treated rats. Moreover, the MQZJFD markedly suppressed the over expressions of p-p65/p65 and p-IκBα/IκBα, but upregulated the Nrf2. MQZJFD also suppressed the protein expressions of p-ERK1/2/ERK1/2, p-p38/p38 and p-JNK/JNK in the lung tissues of BLM-treated rats.

CONCLUSIONS

MQZJFD could improve the pulmonary fibrosis induced by BLM in rats via inhibiting the fibrosis and oxidative stress via suppressing the activation of NF-κB/Nrf2 and MAPKs pathways.

Berberine hydrochloride ameliorates PM2.5-induced pulmonary fibrosis in mice through inhibiting oxidative stress and inflammatory

Elevated levels of respirable particulate matter (PM) have been strongly linked to disease incidence and mortality in population-based epidemiological studies. Berberine hydrochloride (BBR), an isoquinoline alkaloid found in Coptis chinensis, exhibits antipyretic, anti-inflammatory, and antioxidant properties. However, the protective effects and underlying mechanism of BBR against pulmonary fibrosis remain unclear. This study aimed to investigate the protective effect of BBR on lung tissue damage using a mouse model of PM2.5-induced pulmonary fibrosis. SPF grade C57BL/6 mice were randomly assigned to four groups, each consisting of 10 mice. The mice were pretreated with BBR (50 mg/kg) by gavage for 45 consecutive days. A tracheal drip of PM2.5 suspension (8 mg/kg) was administered once every three days for a total of 15 times to induce lung fibrosis. Moreover, the results demonstrated that PM2.5 was found to inhibit the PPARγ signaling pathway, increase ROS expression, upregulate protein levels of IL-6, IL-1β, TNF-α, as well as regulation of gene expression of STAT3 and SOCS3. Importantly, PM2.5 induced lung fibrosis by promoting collagen deposition, upregulating gene expression of fibrosis markers (TGF-β1, FN, α-SMA, COL-1, and COL-3), and downregulating E-cadherin expression. Remarkably, our findings suggest that these injuries could be reversed by BBR pretreatment. BBR acts as a PPARγ agonist in PM2.5-induced pulmonary fibrosis, activating the PPARγ signaling pathway to mitigate oxidative and inflammatory factor-mediated lung injury. This study provides valuable insights for the future prevention and treatment of pulmonary fibrosis.

Unleashing the Potential of Nrf2: A Novel Therapeutic Target for Pulmonary Vascular Remodeling

Pulmonary vascular remodeling, characterized by the thickening of all three layers of the blood vessel wall, plays a central role in the pathogenesis of pulmonary hypertension (PH). Despite the approval of several drugs for PH treatment, their long-term therapeutic effect remains unsatisfactory, as they mainly focus on vasodilation rather than addressing vascular remodeling. Therefore, there is an urgent need for novel therapeutic targets in the treatment of PH. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a vital transcription factor that regulates endogenous antioxidant defense and emerges as a novel regulator of pulmonary vascular remodeling. Growing evidence has suggested an involvement of Nrf2 and its downstream transcriptional target in the process of pulmonary vascular remodeling. Pharmacologically targeting Nrf2 has demonstrated beneficial effects in various diseases, and several Nrf2 inducers are currently undergoing clinical trials. However, the exact potential and mechanism of Nrf2 as a therapeutic target in PH remain unknown. Thus, this review article aims to comprehensively explore the role and mechanism of Nrf2 in pulmonary vascular remodeling associated with PH. Additionally, we provide a summary of Nrf2 inducers that have shown therapeutic potential in addressing the underlying vascular remodeling processes in PH. Although Nrf2-related therapies hold great promise, further research is necessary before their clinical implementation can be fully realized.

Searching for Novel Candidate Small Molecules for Ameliorating Idiopathic Pulmonary Fibrosis: a Narrative Review

Idiopathic pulmonary fibrosis (IPF) can be defined as a progressive chronic pulmonary disease showing scarring in the lung parenchyma, thereby resulting in increase in mortality and decrease in the quality of life. The pathophysiologic mechanism of fibrosis in IPF is still unclear. Repetitive microinjuries to alveolar epithelium with genetical predisposition and an abnormal restorative reaction accompanied by excessive deposition of collagens are involved in the pathogenesis. Although the two FDA-approved drugs, pirfenidone and nintedanib, are under use for retarding the decline in lung function of patients suffered from IPF, they are not able to improve the survival rate or quality of life. Therefore, a novel therapeutic agent acting on the major steps of the pathogenesis of disease and/or, at least, managing the clinical symptoms of IPF should be developed for the effective regulation of this incurable disease. In the present review, we tried to find a potential of managing the clinical symptoms of IPF by natural products derived from medicinal plants used for controlling the pulmonary inflammatory diseases in traditional Asian medicine. A multitude of natural products have been reported to exert an antifibrotic effect in vitro and in vivo through acting on the epithelial-mesenchymal transition pathway, transforming growth factor (TGF)-β-induced intracellular signaling, and the deposition of extracellular matrix. However, clinical antifibrotic efficacy of these natural products on IPF have not been elucidated yet. Thus, those effects should be proven by further examinations including the randomized clinical trials, in order to develop the ideal and optimal candidate for the therapeutics of IPF.

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.

Natural plant resource flavonoids as potential therapeutic drugs for pulmonary fibrosis

Pulmonary fibrosis is an enduring and advancing pulmonary interstitial disease caused by multiple factors that ultimately lead to structural changes in normal lung tissue. Currently, pulmonary fibrosis is a global disease with a high degree of heterogeneity and mortality rate. Nitidine and pirfenidone have been approved for treating pulmonary fibrosis, and the quest for effective therapeutic drugs remains unabated. In recent years, the anti-pulmonary fibrosis properties of natural flavonoids have garnered heightened attention, although further research is needed. In this paper, the resources, structural characteristics, anti-pulmonary fibrosis properties and mechanisms of natural flavonoids were reviewed. We hope to provide potential opportunities for the application of flavonoids in the fight against pulmonary fibrosis.

Dinebra retroflexa Herbal Phytotherapy: A Simulation Study Based on Bleomycin-Induced Pulmonary Fibrosis Retraction Potential in Swiss Albino Rats

Background and Objectives: Fibrotic lung disease is one of the main complications of many medical conditions. Therefore, the use of anti-fibrotic agents may provide a chance to prevent, or at least modify, such complication. The aim of this study was to evaluate the protective pulmonary anti-fibrotic and anti-inflammatory effects of Dinebra retroflexa. Materials and methods: Dinebra retroflexa methanolic extract and its synthesized silver nanoparticles were tested on bleomycin-induced pulmonary fibrosis. Pulmonary fibrosis was induced by intratracheal instillation of bleomycin (5 mg/5 mL/kg-Saline) as a supposed model for induced lung fibrosis. The weed evaluation was performed by intratracheal instillation of Dinebra retroflexa methanolic extract and its silver nanoparticles (35 mg/100 mL/kg-DMSO, single dose). Results: The results showed that both Dinebra retroflexa methanolic extract and its silver nanoparticles had a significant pulmonary fibrosis retraction potential, with Ashcroft scores of three and one, respectively, and degrees of collagen deposition reduction of 33.8 and 46.1%, respectively. High-resolution UHPLC/Q-TOF-MS/MS metabolic profiling and colorimetrically polyphenolic quantification were performed for further confirmation and explanation of the represented effects. Such activity was believed to be due to the tentative identification of twenty-seven flavonoids and one phenolic acid along with a phenolic content of 57.8 mg/gm (gallic acid equivalent) and flavonoid content of 22.5 mg/gm (quercetin equivalent). Conclusion: Dinebra retroflexa may be considered as a promising anti-fibrotic agent for people at high risk of complicated lung fibrosis. The results proved that further clinical trials would be recommended to confirm the proposed findings.

A glucocorticoid-receptor agonist ameliorates bleomycin-induced alveolar simplification in newborn rats

BACKGROUND

Glucocorticoids (GCs) are highly effective yet problematic agents against bronchopulmonary dysplasia (BPD). The dimeric trans-activation of GCs induces unfavorable effects, while monomeric trans-repression suppresses inflammation-related genes. Recently, non-steroidal-selective glucocorticoid-receptor agonists and modulators (SEGRAMs) with only the trans-repressive action have been designed.

METHODS

Using a bleomycin (Bleo)-induced alveolar simplification newborn rat model (recapitulating arrested alveolarization during BPD), we evaluated the therapeutic effects of compound-A (CpdA), a SEGRAM. Sprague-Dawley rats were administered Bleo from postnatal day (PD) 0 to 10 and treated with dexamethasone (Dex) or CpdA from PD 0 to 13. The morphological changes and mRNA expression of inflammatory mediators, including interleukin (IL)-1β, C-X-C motif chemokine ligand 1 (CXCL1), and C-C motif chemokine 2 (CCL2) were investigated.

RESULTS

Similar to the effects of Dex, CpdA exerted protective effects on morphological derangements and inhibited macrophage infiltration and production of pro-inflammatory mediators in Bleo-treated animals. The effects of CpdA were probably mediated by GC receptor (GR)-dependent trans-repression, because unlike the Dex-treated group, anti-inflammatory genes specifically induced by GR-dependent trans-activation (such as "glucocorticoid-induced leucine zipper, GILZ") were not upregulated.

CONCLUSIONS

CpdA improved lung inflammation, inhibited the arrest of alveolar maturation, and restored histological and biochemical changes in a Bleo-induced alveolar simplification model.

IMPACT

SEGRAMs have attracted widespread attention because they are expected to not exhibit unfavorable effects of GCs. Compound A, one of the SEGRAMs, improved lung morphometric changes and decreased lung inflammation in a bleomycin-induced arrested alveolarization, a newborn rat model representing one of the main features of BPD pathology. Compound A did not elicit bleomycin-induced poor weight gain, in contrast to dexamethasone treatment. SEGRAMs, including compound A, may be promising candidates for the therapy of BPD with less adverse effects compared with GCs.

The Mortality Risk and Pulmonary Fibrosis Investigated by Time-Resolved Fluorescence Spectroscopy from Plasma in COVID-19 Patients

A method of rapidly pointing out the risk of developing persistent pulmonary fibrosis from a sample of blood is extraordinarily needed for diagnosis, prediction of death, and post-infection prognosis assessment. Collagen scar formation has been found to play an important role in the lung remodeling following SARS-CoV-2 infection. For this reason, the concentration of collagen degradation products in plasma may reflect the process of lung remodeling and determine the extent of fibrosis. According to our previously published results of an in vitro study, an increase in the concentration of type III collagen degradation products in plasma resulted in a decrease in the fluorescence lifetime of plasma at a wavelength of 450 nm. The aim of this study was to use time-resolved fluorescence spectroscopy to assess pulmonary fibrosis, and to find out if the lifetime of plasma fluorescence is shortened in patients with COVID-19. The presented study is thus far the only one to explore the fluorescence lifetime of plasma in patients with COVID-19 and pulmonary fibrosis. The time-resolved spectrometer Life Spec II with the sub-nanosecond pulsed 360 nm EPLED® diode was used in order to measure the fluorescence lifetime of plasma. The survival analysis showed that COVID-19 mortality was associated with a decreased mean fluorescence lifetime of plasma. The AUC of mean fluorescence lifetime in predicting death was 0.853 (95% CI 0.735−0.972, p < 0.001) with a cut-off value of 7 ns, and with 62% sensitivity and 100% specificity. We observed a significant decrease in the mean fluorescence lifetime in COVID-19 non-survivors (p < 0.001), in bacterial pneumonia patients without COVID-19 (p < 0.001), and in patients diagnosed with idiopathic pulmonary fibrosis (p < 0.001), relative to healthy subjects. Furthermore, these results suggest that the development of pulmonary fibrosis may be a real and serious problem in former COVID-19 patients in the future. A reduction in the mean fluorescence lifetime of plasma was observed in many patients 6 months after discharge. On the basis of these data, it can be concluded that a decrease in the mean fluorescence lifetime of plasma at 450 nm may be a risk factor for mortality, and probably also for pulmonary fibrosis in hospitalized COVID-19 patients.

Long noncoding RNA GAS5 inhibits LX-2 cells activation by suppressing NF-κB signalling through regulation of the miR-433-3p/TLR10 axis

BACKGROUND

Liver fibrosis is a common disease that can lead to hepatic failure.

AIMS

Our aims were to reveal the role of GAS5 in the regulation of liver fibrosis.

METHODS

LX-2 human hepatic satellite cells (HSCs) were cultured and activated using TGF-β1 treatment. A CCK-8 assay was performed to assess cell viability. A luciferase assay was employed to monitor the interactions between miR-433-3p and GAS5 or toll-like receptor 10 (TLR10). Western blotting and real-time quantitative PCR (RT-qPCR) were applied to detect the expression levels of α-SMA, Col. I, PCNA-, MMP2-, MMP9-, TLR10-, and NF-κB-related molecules at the protein and RNA levels.

RESULTS

GAS5 and TLR10 were decreased while miR-433-3p was upregulated in TGF-β1-activated LX-2 cells. Upregulation of GAS5 or downregulation of miR-433-3p suppressed HSC activation, and luciferase assays indicated that miR-433-3p binds with GAS5 and the 3'-UTR of TLR10. MiR-433-3p upregulation and TLR10 downregulation rescued the impacts of GAS5 overexpression or miR-433-3p knockdown on LX-2 cells. Upregulation of GAS5 also suppressed the phosphorylation of NF-κB through the miR-433-3p/TLR10 axis.

CONCLUSION

LncRNA GAS5 exerts an inhibitory effect on HSC activation by suppressing NF-κB signalling through regulation of the miR-433-3p/TLR10 axis.

Protective effects of intranasal curcumin on silica-induced lung damage

OBJECTIVE

Being anti-inflammatory and an antioxidant in nature, curcumin has been studied for its anti-asthmatic effects, but its impact on silicosis has not been investigated before. It is a form of occupational lung illness caused by inhaling crystalline silica. It is particularly common among those who work in construction-related sectors. Therefore, present study has been undertaken to investigate impact of intranasal curcumin on silica induced lung damage in mice model of silicosis.

MATERIALS AND METHODS

Mice model of silicosis was developed by intranasal silica instillation (2.5 mg/mice) for different durations mainly 7, 14 and 21 days, where the longest duration of silica exposure (21 days) mimics chronic occupational exposure of silica dust leading to silicosis. Curcumin (5 mg/kg,i.n) and /or dexamethasone, a known corticosteroid (10 mg/kg,i.p) was administered an hour prior to silica administration.

RESULTS

Present study revealed silica induced lung damage in the mice model of silicosis characterized by airway inflammation, collagen deposition and enhanced expression of fibrosis markers (MMP-9, α-SMA, Hydroxyproline), which were significantly reduced in curcumin treatment groups. Inhibitory effects of curcumin were compared with standard drug, dexamethasone, a corticosteroid and was found better in protecting structural alterations in the lung. Damaged and abnormal mitochondria (enlarged and irregular shapes) were observed in silicosis group which were reduced in curcumin and dexamethasone treatment groups as revealed in transmission electron microscopic studies.

CONCLUSIONS

Present study shows protective effects of intranasal curcumin on silica-induced airway inflammation and structural changes thereby lung damage. Hence, it can be considered as an alternative and complementary medication for silicosis.

The Hydroalcoholic Extract of Nasturtium officinale Reduces Lung Inflammation and Oxidative Stress in an Ovalbumin-Induced Rat Model of Asthma

Background

Asthma is known as a disease that causes breathing problems in children and adults and is also associated with chronic inflammation and oxidative stress of the airways. Nasturtium officinale (NO) possesses a wide range of pharmacological properties, particularly anti-inflammation and antioxidant potentials. Thus, this study for the first time was aimed to investigate anti-inflammatory and antioxidative activities of NO extract (NOE) in an ovalbumin-induced rat model of asthma.

Materials and Methods

Forty-four male Wistar rats were sensitized with ovalbumin (OVA) to induce asthma symptoms. The animals were allocated into five groups: control (C), asthmatic (A), A + NOE (500 mg/kg), NOE (500 mg/kg), and A + dexamethasone (DX, 2.5 mg/kg). After 7 days, blood and tissue samples were taken from the rats. Then, the level of inflammatory markers, oxidative stress parameters, and antioxidant enzymes activity were measured.

Results

The obtained results showed that OVA-sensitive rats significantly increased the levels of pro-inflammatory cytokines IL-1B, TGF-β, and SMA-α compared to the control group (p < 0.05), while treatment with NOE remarkably reduced the SMA-α gene expression compared to the asthma group (p < 0.05). Furthermore, it decreased the expression of IL-1B and TNF-α genes, although it was not statistically significant. The level of glutathione peroxidase (GPX) significantly reduced in A group compared to the C group (p < 0.05), whereas NOE administration significantly increased this marker (p < 0.05). Moreover, NOE attenuated inflammation and alveolar injury in the lungs of OVA-sensitive rat compared to the nontreated A group.

Conclusions

Overall, our findings demonstrated that NOE somewhat is able to reduce airway inflammation by reducing inflammatory and increasing GPX activity. Indeed, further experiments investigating the impact of different extract doses are needed to confirm the antioxidant and anti-inflammatory effects of NOE.

Natural Product-Based Potential Therapeutic Interventions of Pulmonary Fibrosis

Pulmonary fibrosis (PF) is a disease-refractive lung condition with an increased rate of mortality. The potential factors causing PF include viral infections, radiation exposure, and toxic airborne chemicals. Idiopathic PF (IPF) is related to pneumonia affecting the elderly and is characterized by recurring scar formation in the lungs. An impaired wound healing process, defined by the dysregulated aggregation of extracellular matrix components, triggers fibrotic scar formation in the lungs. The potential pathogenesis includes oxidative stress, altered cell signaling, inflammation, etc. Nintedanib and pirfenidone have been approved with a conditional endorsement for the management of IPF. In addition, natural product-based treatment strategies have shown promising results in treating PF. In this study, we reviewed the recently published literature and discussed the potential uses of natural products, classified into three types—isolated active compounds, crude extracts of plants, and traditional medicine, consisting of mixtures of different plant products—in treating PF. These natural products are promising in the treatment of PF via inhibiting inflammation, oxidative stress, and endothelial mesenchymal transition, as well as affecting TGF-β-mediated cell signaling, etc. Based on the current review, we have revealed the signaling mechanisms of PF pathogenesis and the potential opportunities offered by natural product-based medicine in treating PF.

Gypenosides Attenuate Pulmonary Fibrosis by Inhibiting the AKT/mTOR/c-Myc Pathway

Gypenosides (Gyps), the major active constituents isolated from Gynostemma pentaphyllum, possess anti-inflammatory and antioxidant activities. Previous studies have demonstrated that Gyps displayed potent ameliorative effects on liver fibrosis and renal fibrosis. In this study, we found that Gyps significantly reduced the mortality of bleomycin-induced pulmonary fibrosis mice (40% mortality rate of mice in the model group versus 0% in the treatment group). Masson staining showed that Gyps could reduce the content of collagen in the lung tissue of pulmonary fibrosis mice Masson staining and immunohistochemistry demonstrated that the expression of the collagen gene α-SMA and fibrosis gene Col1 markedly decreased after Gyps treatment. The active mitosis of fibroblasts is one of the key processes in the pathogenesis of fibrotic diseases. RNA-seq showed that Gyps significantly inhibited mitosis and induced the G2/M phase cell cycle arrest. The mTOR/c-Myc axis plays an important role in the pathological process of pulmonary fibrosis. RNA-seq also demonstrated that Gyps inhibited the mTOR and c-Myc signaling in pulmonary fibrosis mice, which was further validated by Western blot and immunohistochemistry. AKT functions as an upstream molecule that regulates mTOR. Our western blot data showed that Gyps could suppress the activation of AKT. In conclusion, Gyps exerted anti-pulmonary fibrosis activity by inhibiting the AKT/mTOR/c-Myc pathway.

COVID-19: Immunohistochemical Analysis of TGF-β Signaling Pathways in Pulmonary Fibrosis

Acute respiratory distress syndrome (ARDS) followed by repair with lung remodeling is observed in COVID-19. These findings can lead to pulmonary terminal fibrosis, a form of irreversible sequelae. There is evidence that TGF-β is intimately involved in the fibrogenic process. When activated, TGF-β promotes the differentiation of fibroblasts into myofibroblasts and regulates the remodeling of the extracellular matrix (ECM). In this sense, the present study evaluated the histopathological features and immunohistochemical biomarkers (ACE-2, AKT-1, Caveolin-1, CD44v6, IL-4, MMP-9, α-SMA, Sphingosine-1, and TGF-β1 tissue expression) involved in the TGF-β1 signaling pathways and pulmonary fibrosis. The study consisted of 24 paraffin lung samples from patients who died of COVID-19 (COVID-19 group), compared to 10 lung samples from patients who died of H1N1pdm09 (H1N1 group) and 11 lung samples from patients who died of different causes, with no lung injury (CONTROL group). In addition to the presence of alveolar septal fibrosis, diffuse alveolar damage (DAD) was found to be significantly increased in the COVID-19 group, associated with a higher density of Collagen I (mature) and III (immature). There was also a significant increase observed in the immunoexpression of tissue biomarkers ACE-2, AKT-1, CD44v6, IL-4, MMP-9, α-SMA, Sphingosine-1, and TGF-β1 in the COVID-19 group. A significantly lower expression of Caveolin-1 was also found in this group. The results suggest the participation of TGF-β pathways in the development process of pulmonary fibrosis. Thus, it would be plausible to consider therapy with TGF-β inhibitors in those patients recovered from COVID-19 to mitigate a possible development of pulmonary fibrosis and its consequences for post-COVID-19 life quality.

Fluorofenidone attenuates paraquat‑induced pulmonary fibrosis by regulating the PI3K/Akt/mTOR signaling pathway and autophagy

Paraquat (PQ) is a widely used herbicide that is severely toxic to humans and animals. Pulmonary fibrosis is a disorder that can result from PQ poisoning. Fluorofenidone (AKF‑PD) is a novel small molecule pyridone drug with a widespread and clear anti‑organ fibrosis effect; however, its mechanism of action on PQ poisoning‑induced pulmonary fibrosis is not clear. The purpose of the present study was to investigate the protective effect and underlying mechanism of AKF‑PD on PQ poisoning‑induced pulmonary fibrosis. Human alveolar epithelial cells (HPAEpiC) and Sprague‑Dawley rats were treated with AKF‑PD in the presence or absence of PQ. Hematoxylin‑eosin and Masson staining were used to observe the morphological changes in lung tissue. Cell Counting Kit‑8 and lactate dehydrogenase assays were used to evaluate the viability of HPAEpiC cells. ELISA was used to detect inflammatory factors and the collagen content. Finally, the effects of AKF‑PD on pulmonary fibrosis, as well as the underlying mechanisms, were evaluated via western blotting, reverse transcription‑quantitative PCR and immunofluorescence analysis. AKF‑PD effectively alleviated PQ‑induced pulmonary fibrosis and reduced the expression of oxidative stress and inflammatory factors. Moreover, AKF‑PD treatment effectively inhibited the PI3K/Akt/mTOR signaling pathway and upregulated autophagy. Overall, these findings suggested that AKF‑PD can alleviate PQ‑induced inflammation and pulmonary fibrosis by inhibiting the PI3K/Akt/mTOR signaling pathway and by upregulating autophagy.

Inhibiting TGF-[Formula: see text] 1-Mediated Cellular Processes as an Effective Strategy for the Treatment of Pulmonary Fibrosis with Chinese Herbal Medicines

Pulmonary fibrosis (PF) is a chronic and irreversible interstitial lung disease that even threatens the lives of some patients infected with COVID-19. PF is a multicellular pathological process, including the initial injuries of epithelial cells, recruitment of inflammatory cells, epithelial-mesenchymal transition, activation and differentiation of fibroblasts, etc. TGF-[Formula: see text]1 acts as a key effect factor that participates in these cellular processes of PF. Recently, much attention was paid to inhibiting TGF-[Formula: see text]1 mediated cell processes in the treatment of PF with Chinese herbal medicines (CHM), an important part of traditional Chinese medicine. Here, this review first summarized the effects of TGF-[Formula: see text]1 in different cellular processes of PF. Then, this review summarized the recent research on CHM (compounds, multi-components, single medicines and prescriptions) to directly and/or indirectly inhibit TGF-[Formula: see text]1 signaling (TLRs, PPARs, micrRNA, etc.) in PF. Most of the research focused on CHM natural compounds, including but not limited to alkaloids, flavonoids, phenols and terpenes. After review, the research perspectives of CHM on TGF-[Formula: see text]1 inhibition in PF were further discussed. This review hopes that revealing the inhibiting effects of CHM on TGF-[Formula: see text]1-mediated cellular processes of PF can promote CHM to be better understood and utilized, thus transforming the therapeutic activities of CHM into practice.