Idiopathic pulmonary fibrosis: Epithelial-mesenchymal interactions and emerging therapeutic targets

The application and prospects of drug delivery systems in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease primarily affecting elderly individuals aged >65 years and has a poor prognosis. No effective treatment is currently available for IPF. The two antipulmonary fibrosis drugs nintedanib and pirfenidone approved by the FDA in the United States have somewhat decelerated IPF progression. However, the side effects of these drugs can lead to poor patient tolerance and compliance with the medications. Researchers have recently developed various methods for IPF treatment, such as gene silencing and pathway inhibitors, which hold great promise in IPF treatment. Nevertheless, the nonselectivity and nonspecificity of drugs often affect their efficacies. Drug delivery systems (DDS) are crucial for delivering drugs to specific target tissues or cells, thereby minimizing potential side effects, enhancing drug bioavailability, and reducing lung deposition. This review comprehensively summarizes the current state of DDS and various delivery strategies for IPF treatment (e.g., nano-delivery, hydrogel delivery, and biological carrier delivery) to completely expound the delivery mechanisms of different drug delivery carriers. Subsequently, the advantages and disadvantages of different DDS are fully discussed. Finally, the challenges and difficulties associated with the use of different DDS are addressed so as to accelerate their rapid clinical translation.

Common biomarkers of idiopathic pulmonary fibrosis and systemic sclerosis based on WGCNA and machine learning

Interstitial lung disease (ILD) is known to be a major complication of systemic sclerosis (SSc) and a leading cause of death in SSc patients. As the most common type of ILD, the pathogenesis of idiopathic pulmonary fibrosis (IPF) has not been fully elucidated. In this study, weighted correlation network analysis (WGCNA), protein‒protein interaction, Kaplan-Meier curve, univariate Cox analysis and machine learning methods were used on datasets from the Gene Expression Omnibus database. CCL2 was identified as a common characteristic gene of IPF and SSc. The genes associated with CCL2 expression in both diseases were enriched mainly in chemokine-related pathways and lipid metabolism-related pathways according to Gene Set Enrichment Analysis. Single-cell RNA sequencing (sc-RNAseq) revealed a significant difference in CCL2 expression in alveolar epithelial type 1/2 cells, mast cells, ciliated cells, club cells, fibroblasts, M1/M2 macrophages, monocytes and plasma cells between IPF patients and healthy donors. Statistical analyses revealed that CCL2 was negatively correlated with lung function in IPF patients and decreased after mycophenolate mofetil (MMF) treatment in SSc patients. Finally, we identified CCL2 as a common biomarker from IPF and SSc, revealing the common mechanism of these two diseases and providing clues for the study of the treatment and mechanism of these two diseases.

Deciphering the cellular and molecular landscape of pulmonary fibrosis through single-cell sequencing and machine learning

Pulmonary fibrosis is characterized by progressive lung scarring, leading to a decline in lung function and an increase in morbidity and mortality. This study leverages single-cell sequencing and machine learning to unravel the complex cellular and molecular mechanisms underlying pulmonary fibrosis, aiming to improve diagnostic accuracy and uncover potential therapeutic targets. By analyzing lung tissue samples from pulmonary fibrosis patients, we identified distinct cellular phenotypes and gene expression patterns that contribute to the fibrotic process. Notably, our findings revealed a significant enrichment of activated B cells, CD4 T cells, macrophages, and specific fibroblast subpopulations in fibrotic versus normal lung tissue. Machine learning analysis further refined these observations, resulting in the development of a diagnostic model with enhanced precision, based on key gene signatures including TMEM52B, PHACTR1, and BLVRB. Comparative analysis with existing diagnostic models demonstrates the superior accuracy and specificity of our approach. Through In vitro experiments involving the knockdown of PHACTR1, TMEM52B, and BLVRB genes demonstrated that these genes play crucial roles in inhibiting the expression of α-SMA and collagen in lung fibroblasts induced by TGF-β. Additionally, knockout of the PHACTR1 gene reduced inflammation and collagen deposition in a bleomycin-induced mouse model of pulmonary fibrosis in vivo. Additionally, our study highlights novel gene signatures and immune cell profiles associated with pulmonary fibrosis, offering insights into potential therapeutic targets. This research underscores the importance of integrating advanced technologies like single-cell sequencing and machine learning to deepen our understanding of pulmonary fibrosis and pave the way for personalized therapeutic strategies.

Inhibition of HIF-1α ameliorates pulmonary fibrosis by suppressing M2 macrophage polarization through PRMT1/STAT6 signals

OBJECTIVE

Pulmonary fibrosis (PF) is a chronic, progressive, and irreversible lung interstitial disease of unknown etiology with a fatal outcome. M2 macrophages have been recognized to play a significant role in PF pathogenesis. The role of protein hypoxia-inducible factor 1-α (HIF-1α) in M2 macrophage polarization in PF is largely unknown. This study aimed to investigate the role of macrophage HIF-1α in the regulation of PF.

METHODS

PF was induced in C57BL/6 mice by the intratracheal injection of bleomycin (BLM), and small hairpin RNA (shRNA) lentiviral construct specifically targeting HIF-1α were designed for in vitro and in vivo experiments. In the in vitro experiment, bone marrow-derived macrophages (BMDMs) were used to explore molecular mechanism analysis. In the in vivo experiment, mice were administered BLM intratracheally on day 0, treated with shRNA on day 7, and sacrificed on day 21. Histopathological techniques (H&E and Masson's trichrome staining) were used to evaluate PF severity. Western blot, immunofluorescence, quantitative real-time PCR, and flow cytometry were performed to explore the underlying mechanisms.

RESULTS

HIF-1α was upregulated and macrophages polarized toward M2 phenotype in BLM-induced mouse pulmonary fibrosis models. By constructing HIF-1α knockdown shRNA lentiviral construct, we found that the knockdown of HIF-1α in macrophages significantly suppressed M2-type polarization in vitro, hence alleviating fibrosis in lung epithelial cells. Further results revealed that HIF-1α in macrophages promoted M2-type polarization by mediating the signal transducer and activator of transcription 6 (STAT6) arginine methylation. Meanwhile, its arginine methylation modification site is at position Arg27. Further experiments indicated that the regulation of STAT6 arginine methylation by HIF-1α mainly depended on the protein arginine methyltransferase 1 (PRMT1). Finally, animal experiments demonstrated that Knockdown of HIF-1α, PRMT1, and STAT6 relieved the BLM-induced pulmonary fibrosis of mice.

CONCLUSION

HIF-1α may act as a novel factor to promote macrophage of the M2 program. Therapeutic approaches to target macrophage HIF-1α may act as a new therapeutic strategy to combat PF in the future.

Phytochemical investigation of Jie-Geng-Tang and regulatory role in the TNF-α pathway in mitigating pulmonary fibrosis using UPLC-Q-TOF/MS

Jie-Geng-Tang (JGT), composed of Platycodon grandiflorus (Jacq.) A. DC and Glycyrrhiza uralensis Fisch, is widely used in traditional Chinese medicine for its potential effects in preventing pulmonary fibrosis (PF). This study systematically explored the effects of JGT's water and 70% EtOH extracts in bleomycin (BLM)-induced PF models. In vitro, the 70% EtOH extract significantly reversed BLM-induced reductions in cell viability and apoptosis, whereas the water extract had limited impact. In vivo, the EtOH extract markedly reduced fibrosis markers, such as α-SMA and collagen-I, alleviating lung tissue damage and collagen deposition. UPLC-Q-TOF/MS analysis revealed that the EtOH extract contained a higher abundance of flavonoids compared to the water extract. Through network pharmacology analysis of the EtOH extract, four key flavonoids-apigenin, kaempferol, kaempferol 3-glucuronoside, and quercetin-were identified as crucial compounds. These flavonoids were found to reverse BLM-induced cell viability loss, with apigenin showing the most pronounced effect by modulating the TNF-α signaling pathway and inhibiting caspase-3 activation. Apigenin, as a primary active component derived from JGT, holds significant potential as a preventive agent against pulmonary fibrosis.

Multi-omics study reveals Shuangshen Pingfei formula regulates EETs metabolic reprogramming to exert its therapeutic effect on pulmonary fibrosis

As a clinical formula derived from Renshen Pingfei San, Shuangshen Pingfei formula (SSPF) has been used to treat pulmonary fibrosis (PF). However, its in-depth mechanism of action remains unknown. In this study, the effect of SSPF was evaluated by applying a rat model of PF caused by intratracheal drip bleomycin. To characterize the molecular changes related to PF and reveal therapeutic targets for SSPF, we performed transcriptomic and metabolomic analyses on rat lung. Finally, western blotting and qPCR experiments were used to validate the multi-omics results. As a result, a significant reduction in inflammation and fibrosis caused by BLM was observed when SSPF was administered. Widespread changes in gene expression and metabolic programming were observed in the lungs of PF rats through RNA-seq and untargeted metabolomic analysis. Combined transcriptomic and metabolomic analyses revealed the involvement of arachidonic acid (AA) metabolism pathways in PF. Further validation of AA metabolite synthase genes and protein levels showed a significant decrease in the levels of epoxyeicosatrienoic acids (EETs) synthases, including Cyp2j2, Cyp2b1, in the PF lungs. SSPF treatment regulated the above changes in gene expression and metabolic programming, particularly the regulation of EETs. This study is the first to investigate the mechanism of action of SSPF in the treatment of PF from the perspective of regulating the synthesis of EETs in AA metabolism.

Pharmacological effects and mechanisms of danlong oral liquid in asthma airway remodeling: Insights from serum medicinal chemistry, network pharmacology, and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Danlong oral liquid (DLOL) is a traditional Chinese proprietary medicine commonly used to treat chronic respiratory diseases, including bronchial asthma and chronic obstructive pulmonary disease. However, the therapeutic effects and pharmacological mechanisms of DLOL in improving airway remodeling remain unclear.

AIMS OF THE STUDY

This study utilizes in vivo and in vitro experiments, serum pharmacological analysis, and network-based pharmacology approaches to investigate the effects and mechanisms of DLOL on airway remodeling and epithelial-mesenchymal transition (EMT) in asthma.

METHODS

An asthma model was established through ovalbumins (OVA) sensitization and challenge in BALB/c mice to observe the effects of DLOL on airway hyperresponsiveness (AHR), inflammation, remodeling, and molecular markers of EMT. The absorbed chemical prototype constituents of DLOL were analyzed using Ultra Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS), and targets for asthma and airway remodeling were predicted using a network pharmacology approach. Key biological processes and signaling pathways were analyzed. Additionally, TGF-β1 was used to induce EMT in BEAS-2B cells. TGF-β1 and DLOL-containing serum were screened to determine the optimal time and concentration in BEAS-2B cells using CCK8 assays. The cell scratch assay was used to assess cell migration, while immunofluorescence and immunohistochemistry were employed to evaluate protein expression levels.

RESULTS

DLOL improved AHR in asthmatic mice, reduced inflammatory cell infiltration in lung tissue, decreased airway wall and smooth muscle thickness, and reduced collagen deposition. It also down-regulated mesenchymal markers (N-cadherin, vimentin, α-SMA) and key remodeling factors (TGF-β1, MMP9), while up-regulating the epithelial marker E-cadherin. A total of 17 absorbed chemical prototype constituents were identified, predicting 54 core targets involved in airway remodeling. Following Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, the key targets were found to be associated with the regulation of cell migration, cell-cell adhesion, and cell adhesion molecular processes, with the PI3K-Akt signaling pathway likely playing a critical role. Cellular experiments confirmed that DLOL-containing serum inhibited TGF-β1-induced EMT in BEAS-2B cells and suppressed the phosphorylation of Akt and GSK-3β.

CONCLUSION

This study identifies, for the first time, the serum medicinal chemistry of DLOL using UPLC-MS. Combining network pharmacology, in vivo and in vitro experiments, it elucidates the effects and potential mechanisms of the drug on airway remodeling and EMT. DLOL may offer a novel therapeutic approach for asthma-related airway remodeling.

The multifaceted role of macrophage mitophagy in SiO2-induced pulmonary fibrosis: A brief review

Prolonged exposure to environments with high concentrations of crystalline silica (CS) can lead to silicosis. Macrophages play a crucial role in the pathogenesis of silicosis. In the process of silicosis, silica (SiO2) invades alveolar macrophages (AMs) and induces mitophagy which usually exists in three states: normal, excessive, and/or deficiency. Different mitophagy states lead to corresponding toxic responses, including successful macrophage repair, injury, necrosis, apoptosis, and even pulmonary fibrosis. This is a complex process accompanied by various cytokines. Unfortunately, the details have not been fully systematically summarized. Therefore, it is necessary to elucidate the role of macrophage mitophagy in SiO2-induced pulmonary fibrosis by systematic analysis on the literature reports. In this review, we first summarized the current data on the macrophage mitophagy in the development of SiO2-induced pulmonary fibrosis. Then, we introduce the molecular mechanism on how SiO2-induced mitophagy causes pulmonary fibrosis. Finally, we focus on introducing new therapies based on newly developed mitophagy-inducing strategies. We conclude that macrophage mitophagy plays a multifaceted role in the progression of SiO2-induced pulmonary fibrosis, and reprogramming the macrophage mitophagy state accordingly may be a potential means of preventing and treating pulmonary fibrosis.

Xuanfei Baidu decoction ameliorates bleomycin-elicited idiopathic pulmonary fibrosis in mice by regulating the lung-gut crosstalk via IFNγ/STAT1/STAT3 axis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial pneumonia, the available treatment option is limited because the etiology and pathological process are not well understood. Although gut-lung axis reported with an emerging area of host-associated microbiota exist in many chronic lung diseases, the connection between gut-lung microbiota composition with in-site inflammation in IPF development is not yet established.

PURPOSE

We aimed to address the microbiota and immunity connection, and make it clear how a listed drug, Xuanfei Baidu Decoction (XFBD) affect the lung-gut crosstalk for IPF amelioration, which was previously reported for restoring disrupted lung in IPF and protecting intestinal injury.

METHODS

Firstly, Micro-CT (μCT) and histopathology were used to check for pathological changes in the lungs and intestines of bleomycin (BLM)-induced IPF mice. Then, Reverse Transcription and Quantitative Real-time PCR (RT-qPCR) and Western blot (WB) assays were employed to detect the integrity of the barrier of lungs and intestines in IPF mice. Subsequently, flow cytometry and 16S rRNA sequencing were used to evaluate the immune and microbial microenvironment of the lungs and intestines. We analyzed the lung-gut microbiota crosstalk for further mechanism exploration.

RESULTS

Firstly, we revealed that XFBD protected the integrity of the lung and intestinal barriers in the IPF mice, as evidenced by the up-regulation of ZO-1, Claudin-1, Occludin, and VE Cadherin protein expression. Then, we analyzed the changing microbiota and T cell in the gut-lung axis in IPF, and with XFBD, six highly relevant microenvironments were demonstrated that crossing damaged lung-gut barriers and XFBD could reverse these chaotic bacterial and immunity micro-environment, among them Akkermansia was an essential bacteria affecting the expression of systemic IFN-γ downstream STAT1/STAT3 axis was also studied. XFBD prominently up-regulated the production of IFN-γ and p-STAT1 and down-regulated p-STAT3, consequently exerting effects on the lung barrier and gut barrier. Taken together, XFBD ameliorated BLM-induced IPF mice by regulating IFNγ/STAT1/STAT3 axis.

CONCLUSION

Altogether, our results revealed that XFBD improved the BLM-elicited IPF mice by regulating gut-lung crosstalk via IFN-γ/STAT1/STAT3 axis and provided a new insight of gut-lung crosstalk in IPF, especially the dynamic changes of microorganisms in the damaged lungs needed to pay more attention during IPF therapy.

METTL3-Dependent YTHDF2 Mediates TSC1 Expression to Regulate Alveolar Epithelial Mesenchymal Transition and Promote Idiopathic Pulmonary Fibrosis

Diffuse, progressive interstitial lung disease with few treatment options and low survival rates is known as idiopathic pulmonary fibrosis (IPF). Alveolar epithelial cell damage and dysfunction are the main features of IPF. TSC1 has been documented to exert a pivotal function in governing cellular growth, proliferation, and ontogenesis. This work investigated TSC1's function and mechanism in IPF. Mice were given BLM to cause pulmonary fibrosis, and A549 cells underwent epithelial mesenchymal transition (EMT) in response to TGF-β1. According to the data, TSC1 expression was reduced in IPF. Overexpression of TSC1 was established by adenopathy-associated virus in vivo and adenovirus in vitro to significantly block the EMT process. Besides, the findings from the RNA-sequencing analysis indicate that overexpression of TSC1 mitigated the EMT process by suppressing the activation of the AKT/mTOR pathway via downregulation of ACTN4 expression. To examine the upstream regulatory mechanism, we employed the SRAMP database to predict m6A modification of TSC1 mRNA, followed by verification of m6A modification levels and expression using MERIP-qPCR, Dot blot, RT-qPCR, and WB. The results indicated a high degree of m6A modification in TSC1 mRNA in pulmonary fibrosis. The expression of METTL3 was further found to be significantly elevated. METTL3 knockdown impeded EMT progression. METTL3 inhibits TSC1 expression by increasing TSC1 m6A modification through the reading protein YTHDF2. In conclusion, our study elucidated that the METTL3/YTHDF2/TSC1 signaling axis activates the AKT/mTOR pathway to promote the development of IPF. This study provides potential molecular-level therapeutic targets for IPF disease.

DsbA-L activates TGF-β1/SMAD3 signaling and M2 macrophage polarization by stimulating AKT1 and NLRP3 to promote pulmonary fibrosis

BACKGROUND

Pulmonary fibrosis (PF) is a progressive and difficult-to-heal lung disease that poses a significant threat to human life and health. This study aimed to investigate the potential pathological mechanisms of PF and to identify new avenues for the treatment of PF.

METHODS

Clinical samples were collected to assess the effect of disulfide-bond A oxidoreductase-like protein (DsbA-L) on PF. TGF-β1-induced MLE-12 cell model and bleomycin (BLM)-induced mice model were established. Changes in physiological morphology and fibrosis were observed in the lung tissues. The degree of apoptosis and the mitochondrial function was analyzed. The expression of relative cytokines was examined. The CD68+/CD206+ ratio was determined to indicate M2 macrophage polarization.

RESULTS

The expression of DsbA-L was upregulated in patients with PF and PF-like models. In vitro, DsbA-L overexpression exacerbated TGF-β1-induced the deposition of extracellular matrix (ECM), apoptosis, inflammation, and mitochondrial damage, whereas DsbA-L silencing exerted the opposite effects. DsbA-L silencing inhibited the activation of AKT1, NLRP3, and SMAD3 by TGF-β1. MLE-12 cells silencing DsbA-L limited the polarization of RAW264.7 cells towards the M2 phenotype. AKT1 agonist or NLRP3 agonist reversed the role of DsbA-L silencing in inhibiting the TGF-β1/SMAD3 pathway and M2 macrophage polarization. In vivo, DsbA-L knockout protected mice from PF-like pathological damage caused by BLM.

CONCLUSION

DsbA-L exhibited a significant profibrotic effect in lung epithelial cells and mice, which increased the levels of AKT1 and NLRP3 to activate the TGF-β1/SMAD3 pathway and M2 macrophage polarization. These findings could shed light on new clues for comprehension and treatment of PF.

CasRx-based Wnt activation promotes alveolar regeneration while ameliorating pulmonary fibrosis in a mouse model of lung injury

Wnt/β-catenin signaling is an attractive target for regenerative medicine. A powerful driver of stem cell activity and hence tissue regeneration, Wnt signaling can promote fibroblast proliferation and activation, leading to fibrosis, while prolonged Wnt signaling is potentially carcinogenic. Thus, to harness its therapeutic potential, the activation of Wnt signaling must be transient, reversible, and tissue specific. In the lung, Wnt signaling is essential for alveolar stem cell activity and alveolar regeneration, which is impaired in lung fibrosis. Activation of Wnt/β-catenin signaling in lung epithelium may have anti-fibrotic effects. Here, we used intratracheal adeno-associated virus 6 injection to selectively deliver CasRx into the lung epithelium, where it reversibly activates Wnt signaling by simultaneously degrading mRNAs encoding Axin1 and Axin2, negative regulators of Wnt/β-catenin signaling. Interestingly, CasRx-mediated Wnt activation specifically in lung epithelium not only promotes alveolar type II cell proliferation and alveolar regeneration but also inhibits lung fibrosis resulted from bleomycin-induced injury, relevant in both preventive and therapeutic settings. Our study offers an attractive strategy for treating pulmonary fibrosis, with general implications for regenerative medicine.

In Vitro Modeling of Idiopathic Pulmonary Fibrosis: Lung-on-a-Chip Systems and Other 3D Cultures

Idiopathic pulmonary fibrosis (IPF) is a lethal disorder characterized by relentless progression of lung fibrosis that causes respiratory failure and early death. Currently, no curative treatments are available, and existing therapies include a limited selection of antifibrotic agents that only slow disease progression. The development of novel therapeutics has been hindered by a limited understanding of the disease's etiology and pathogenesis. A significant challenge in developing new treatments and understanding IPF is the lack of in vitro models that accurately replicate crucial microenvironments. In response, three-dimensional (3D) in vitro models have emerged as powerful tools for replicating organ-level microenvironments seen in vivo. This review summarizes the state of the art in advanced 3D lung models that mimic many physiological and pathological processes observed in IPF. We begin with a brief overview of conventional models, such as 2D cell cultures and animal models, and then explore more advanced 3D models, focusing on lung-on-a-chip systems. We discuss the current challenges and future research opportunities in this field, aiming to advance the understanding of the disease and the development of novel devices to assess the effectiveness of new IPF treatments.

Effect and mechanism of imbalance via Th9 cells and Th17/Treg cells in inflammatory and fibrotic phases of pulmonary fibrosis in mice

We investigate the role and mechanism of imbalance via Th9 cells and Th17/Treg cells in the inflammatory and fibrotic phases of pulmonary fibrosis in mice. A total of mice were split into normal saline (control group) and inflammation and fibrosis mouse models (study group) randomly, and lung tissues and bronchoalveolar lavage fluid (BALF) were obtained from mice at the inflammatory and fibrotic phases on the 7th and 28th day, respectively. The degenerative changes in the mouse lung tissue were then visible using H&E staining. The expression of CCR6 and IL-9 in the lung tissues of two groups was examined through an immunohistochemistry assay. Fluorescence PCR was used to assess the expression of PU.1 mRNA in BALF, and flow cytometry was performed to identify the expression of Th17 and Treg. (1). The level of pulmonary fibrosis and lung inflammation in the research group was significantly higher than in the control group. (2). The expression of Th17, CCR6, IL-9 and PU.1 mRNA was substantially higher (P<0.05) in the research group at different time points; the expression level of Treg cells was considerably lower (P<0.05) in the research group than in the control group. (3). CCR6, IL-9 and PU.1 mRNA levels were statistically directly associated (P<0.05) with Th17 and inversely correlated 40 with Regulatory T cells (Tregs). CCR6 and Th9 cells may be involved in 45 developing Th17/Treg imbalance in the immune inflammation of pulmonary fibrosis, which promotes fibrocyte proliferation in lung tissue.

Tanshinone IIA Loaded Inhaled Polymer Nanoparticles Alleviate Established Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal respiratory disease characterized by chronic, progressive scarring of the lung parenchyma, leading to an irreversible decline in lung function. Apart from supportive care, there is currently no specific treatment available to reverse the disease. Based on the fact that tanshinone IIA (TAN) had an effect on protecting against TGF-β1-induced fibrosis through the inhibition of Smad and non-Smad signal pathways to avoid myofibroblasts activation, this study reported the development of the inhalable tanshinone IIA-loaded chitosan-oligosaccharides-coated poly(lactic-co-glycolic acid) (PLGA) nanoparticles (CPN@TAN) for enhancing the pulmonary delivery of tanshinone IIA to treat pulmonary fibrosis. The CPN@TAN with a size of 206.5 nm exhibited excellent in vitro aerosol delivery characteristics, featuring a mass median aerodynamic diameter (MMAD) of 3.967 ± 0.025 μm and a fine particle fraction (FPF) of 70.516 ± 0.929%. Moreover, the nanoparticles showed good stability during atomization and enhanced the mucosal penetration capabilities. The results of confocal spectroscopy confirmed the potential of the nanoparticles as carriers that facilitated the uptake of drugs by NIH3T3, A549, and MH-S cells. Additionally, the nanoparticles demonstrated good in vitro biocompatibility. In a mouse model of bleomycin-induced pulmonary fibrosis, noninvasive inhalation of aerosol CPN@TAN greatly suppressed collagen formation and facilitated re-epithelialization of the destroyed alveolar epithelium without causing systemic toxicity compared with intravenous administration. Consequently, our noninvasive inhalation drug delivery technology based on polymers may represent a promising paradigm and open the door to overcoming the difficulties associated with managing pulmonary fibrosis.

Interactions between fibroblasts and monocyte-derived cells in chronic lung injuries induced by real-ambient particulate matter exposure

Long-term exposure to fine particulate matter (PM2.5) can lead to chronic lung injury, including inflammation, idiopathic pulmonary fibrosis, and cancer. Mesenchymal cells, such as fibroblasts, myeloid-derived suppressor cells (MDSCs), and interstitial macrophages (IMs), contribute to immune regulation in lung, yet their diversity and functions upon long-term exposure to particulate matter (PM) remain inadequately characterized. In this study, we conducted a 16-week real-ambient PM exposure experiment on C57BL/6 J male mice in Shijiazhuang, China. We used single-cell RNA sequencing to analyze the cellular and molecular changes in lung tissues. Notably, we revealed a significant increase in specific fibroblast (ATX+, Col5a1+Meg3+, universal fibroblasts) and monocyte-derived cell subpopulations (monocytic-MDSCs (M-MDSCs), Lyve1loMHC-Ⅱhi IMs, Lyve1hiMHC-Ⅱlo IMs) that exhibited pro-inflammatory and pro-fibrotic functions. These cell subpopulations engaged in immunosuppressive signaling pathways and interactions with various cytokines, shaping a pulmonary microenvironment similar to those associated with cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs). This altered immune environment may promote the development of pulmonary fibrosis caused by PM exposure, underscoring the intricate roles of mesenchymal cells in chronic lung injury and highlighting the cancer-causing potential of PM2.5 exposure.

SPP1 promotes the polarization of M2 macrophages through the Jak2/Stat3 signaling pathway and accelerates the progression of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal pulmonary disease that requires further investigation to understand its pathogenesis. The present study demonstrated that secreted phosphoprotein 1 (SPP1) was aberrantly highly expressed in the lung tissue of patients with IPF and was significantly positively associated with macrophage and T‑cell activity. Cell localization studies revealed that SPP1 was primarily overexpressed in macrophages, rather than in T cells. Functionally, knocking down SPP1 expression in vitro inhibited the secretion of fibrosis‑related factors and M2 polarization in macrophages. Furthermore, knocking down SPP1 expression inhibited the macrophage‑induced epithelial‑to‑mesenchymal transition in both epithelial and fibroblastic cells. Treatment with SPP1 inhibitors in vivo enhanced lung function and ameliorated pulmonary fibrosis. Mechanistically, SPP1 appears to promote macrophage M2 polarization by regulating the JAK/STAT3 signaling pathway both in vitro and in vivo. In summary, the present study found that SPP1 promotes M2 polarization of macrophages through the JAK2/STAT3 signaling pathway, thereby accelerating the progression of IPF. Inhibition of SPP1 expression in vivo can effectively alleviate the development of IPF, indicating that SPP1 in macrophages may be a potential therapeutic target for IPF.

Cepharanthine attenuates pulmonary fibrosis via modulating macrophage M2 polarization

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a group of chronic interstitial pulmonary diseases characterized by myofibroblast proliferation and extracellular matrix (ECM) deposition. However, current treatments are not satisfactory. Therefore, more effective therapies need to be explored. Cepharanthine (CEP) is a naturally occurring alkaloid that has recently been reported to have multiple pharmacological effects, particularly in chronic inflammation.

METHODS

For in vivo experiments, first, a pulmonary fibrosis murine model was generated via tracheal injection of bleomycin (BLM). Second, the clinical manifestations and histopathological changes of the mice were used to verify that treatment with CEP might significantly reduce BLM-induced fibrosis. Furthermore, flow cytometric analysis was used to analyze the changes in the number of M2 macrophages in the lung tissues before and after treatment with CEP to explore the relationship between macrophage M2 polarization and pulmonary fibrosis. In vitro, we constructed two co-culture systems (THP-1 and MRC5 cells, RAW264.7 and NIH 3T3 cells), and measured the expression of fibrosis-related proteins to explore whether CEP could reduce pulmonary fibrosis by regulating macrophage M2 polarization and fibroblast activation.

RESULTS

The results showed that the intranasal treatment of CEP significantly attenuated the symptoms of pulmonary fibrosis induced by BLM in a murine model. Our findings also indicated that CEP treatment markedly reduced the expression of fibrosis markers, including TGF-β1, collagen I, fibronectin and α-SMA, in the mouse lung. Furthermore, in vitro studies demonstrated that CEP attenuated pulmonary fibrosis by inhibiting fibroblast activation through modulating macrophage M2 polarization and reducing TGF-β1 expression.

CONCLUSIONS

This study demonstrated the potential and efficacy of CEP in the treatment of pulmonary fibrosis. In particular, this study revealed a novel mechanism of CEP in inhibiting fibroblast activation by regulating macrophage M2 polarization and reducing the expression of fibrosis-associated factors. Our findings open a new direction for future research into the treatment of pulmonary fibrosis.

Antioxidant, Antiinflammation, and Antifibrotic Activity of Ciplukan (Physalis angulata L). Extract

Purpose

Physalis angulata Linn. (Ciplukan) is a plant widely used in traditional medicine in subtropical and tropical regions. Most studies focus on its antioxidant and anti-inflammatory activity. Many studies also reported its therapeutic potential for treating cancer, malaria, hepatitis, rheumatism, liver problems, and tumors, but few studies have reported its anti-fibrosis activity. Here, we aimed to investigate the potential of P. angulata as an antioxidant and anti-inflammatory that may be correlated with its anti-fibrosis action.

Methods

In our study, we treated 3T3-L1 and TGF-β-induced 3T3-L1 cells with an ethanol extract of P. angulata. We then monitored the cell's response, evaluated the antioxidant activity using an MTT assay, and observed the cells' migration using the cell scratch assay. We used RT-PCR to determine the expression of HIF-1α and IL-6 on TGF-β-induced 3T3-L1 cells.

Results

The ethanol extract of P. angulata showed antioxidant activity and promoted cell proliferation on 3T3-L1 cells. Interestingly, the extract inhibited the migration of TGF-β-induced 3T3-L1 cells. Further analysis revealed that the extract could inhibit HIF-1α expression and suppress IL-6 expression on TGF-β-induced 3T3-L1 cells.

Conclusion

The ethanol extract of P. angulata showed antioxidant and anti-inflammation activities in 3T3-L1 cells. Both activities are associated with the antifibrotic activity of P. angulata's ethanol extract.

Licoricesaponin G2 ameliorates bleomycin-induced pulmonary fibrosis via targeting TNF-α signaling pathway and inhibiting the epithelial-mesenchymal transition

Background

Pulmonary fibrosis (PF) emerges as a significant pulmonary sequelae in the convalescent phase of coronavirus disease 2019 (COVID-19), with current strategies neither specifically preventive nor therapeutic. Licoricesaponin G2 (LG2) displays a spectrum of natural activities, including antibacterial, anti-inflammatory, and antioxidant properties, and has been effectively used in treating various respiratory conditions. However, the potential protective effects of LG2 against PF remain underexplored.

Methods

Network analysis and molecular docking were conducted in combination to identify the core targets and pathways through which LG2 acts against PF. In the model of bleomycin (BLM)-induced C57 mice and transforming growth factor-β1 (TGF-β1)-induced A549 and MRC5 cells, techniques such as western blot (WB), quantitative Real-Time PCR (qPCR), Immunohistochemistry (IHC), Immunofluorescence (IF), and Transwell migration assays were utilized to analyze the expression of Epithelial-mesenchymal transition (EMT) and inflammation proteins. Based on the analysis above, we identified targets and potential mechanisms underlying LG2's effects against PF.

Results

Network analysis has suggested that the mechanism by which LG2 combats PF may involve the TNF-α pathway. Molecular docking studies have demonstrated a high binding affinity of LG2 to TNF-α and MMP9. Observations from the study indicated that LG2 may mitigate PF by modulating EMT and extracellular matrix (ECM) remodeling. It is proposed that the therapeutic effect is likely arises from the inhibition of inflammatory expression through regulation of the TNF-α pathway.

Conclusion

LG2 mitigates PF by suppressing TNF-α signaling pathway activation, modulating EMT, and remodeling the ECM. These results provide compelling evidence supporting the use of LG2 as a potential natural therapeutic agent for PF in clinical trials.

Spatially resolved metabolomics visualizes heterogeneous distribution of metabolites in lung tissue and the anti-pulmonary fibrosis effect of Prismatomeris connate extract

Pulmonary fibrosis (PF) is a chronic progressive end-stage lung disease. However, the mechanisms underlying the progression of this disease remain elusive. Presently, clinically employed drugs are scarce for the treatment of PF. Hence, there is an urgent need for developing novel drugs to address such diseases. Our study found for the first time that a natural source of Prismatomeris connata Y. Z. Ruan (Huang Gen, HG) ethyl acetate extract (HG-2) had a significant anti-PF effect by inhibiting the expression of the transforming growth factor beta 1/suppressor of mothers against decapentaplegic (TGF-β1/Smad) pathway. Network pharmacological analysis suggested that HG-2 had effects on tyrosine kinase phosphorylation, cellular response to reactive oxygen species, and extracellular matrix (ECM) disassembly. Moreover, mass spectrometry imaging (MSI) was used to visualize the heterogeneous distribution of endogenous metabolites in lung tissue and reveal the anti-PF metabolic mechanism of HG-2, which was related to arginine biosynthesis and alanine, asparate and glutamate metabolism, the downregulation of arachidonic acid metabolism, and the upregulation of glycerophospholipid metabolism. In conclusion, we elaborated on the relationship between metabolite distribution and the progression of PF, constructed the regulatory metabolic network of HG-2, and discovered the multi-target therapeutic effect of HG-2, which might be conducive to the development of new drugs for PF.

Enzyme-like nanoparticle-engineered mesenchymal stem cell secreting HGF promotes visualized therapy for idiopathic pulmonary fibrosis in vivo

Stem cell therapy is being explored as a potential treatment for idiopathic pulmonary fibrosis (IPF), but its effectiveness is hindered by factors like reactive oxygen species (ROS) and inflammation in fibrotic lungs. Moreover, the distribution, migration, and survival of transplanted stem cells are still unclear, impeding the clinical advancement of stem cell therapy. To tackle these challenges, we fabricate AuPtCoPS trimetallic-based nanocarriers (TBNCs), with enzyme-like activity and plasmid loading capabilities, aiming to efficiently eradicate ROS, facilitate delivery of therapeutic genes, and ultimately improve the therapeutic efficacy. TBNCs also function as a computed tomography contrast agent for tracking mesenchymal stem cells (MSCs) during therapy. Accordingly, we enhanced the antioxidant stress and anti-inflammatory capabilities of engineered MSCs and successfully visualized their biological behavior in IPF mice in vivo. Overall, this study provides an efficient and forward-looking treatment approach for IPF and establishes a framework for a stem cell-based therapeutic system aimed at addressing lung disease.

The mechanism of action of Botrychium (Thunb.) Sw. for prevention of idiopathic pulmonary fibrosis based on 1H-NMR-based metabolomics

OBJECTIVES

This study aimed to reveal the anti-fibrotic effects of Botrychium ternatum (Thunb.) Sw. (BT) against idiopathic pulmonary fibrosis (IPF) and to preliminarily analyze its potential mechanism on bleomycin-induced IPF rats.

METHODS

The inhibition of fibrosis progression in vivo was assessed by histopathology combined with biochemical indicators. In addition, the metabolic regulatory mechanism was investigated using 1H-nuclear magnetic resonance-based metabolomics combined with multivariate statistical analysis.

KEY FINDINGS

Firstly, biochemical analysis revealed that BT notably suppressed the expression of hydroxyproline and transforming growth factor-β1 in the pulmonary tissue. Secondly, Masson's trichrome staining and hematoxylin and eosin showed that BT substantially improved the structure of the damaged lung and significantly inhibited the proliferation of collagen fibers and the deposition of extracellular matrix. Finally, serum metabolomic analysis suggested that BT may exert anti-fibrotic effects by synergistically regulating tyrosine metabolism; phenylalanine, tyrosine and tryptophan biosynthesis; and synthesis and degradation of ketone bodies.

CONCLUSIONS

Our study not only clarifies the potential anti-fibrotic mechanism of BT against IPF at the metabolic level but also provides a theoretical basis for developing BT as an effective anti-fibrotic agent.

Monomeric compounds from natural products for the treatment of pulmonary fibrosis: a review

Pulmonary fibrosis (PF) is the end stage of lung injury and chronic lung diseases that results in diminished lung function, respiratory failure, and ultimately mortality. Despite extensive research, the pathogenesis of this disease remains elusive, and effective therapeutic options are currently limited, posing a significant clinical challenge. In addition, research on traditional Chinese medicine and naturopathic medicine is hampered by several complications due to complex composition and lack of reference compounds. Natural product monomers, possessing diverse biological activities and excellent safety profiles, have emerged as potential candidates for preventing and treating PF. The effective anti-PF ingredients identified can be generally divided into flavonoids, saponins, polysaccharides, and alkaloids. Specifically, these monomeric compounds can attenuate inflammatory response, oxidative stress, and other physiopathological processes of the lung through many signaling pathways. They also improve pulmonary factors. Additionally, they ameliorate epithelial-mesenchymal transition (EMT) and fibroblast-myofibroblast transdifferentiation (FMT) by regulating multiple signal amplifiers in the lungs, thereby mitigating PF. This review highlights the significant role of monomer compounds derived from natural products in reducing inflammation, oxidative stress, and inhibiting EMT process. The article provides comprehensive information and serves as a solid foundation for further exploration of new strategies to harness the potential of botanicals in the treatment of PF.

Ginkgo biloba Extract 50 (GBE50) Exerts Antifibrotic and Antioxidant Effects on Pulmonary Fibrosis in Mice by Regulating Nrf2 and TGF-β1/Smad Pathways

BACKGROUND

Pulmonary fibrosis (PF) is a progressive lung disorder with a poor prognosis. GBE50 is a new standardized Ginkgo biloba extract that has been widely used in cardiovascular diseases. However, the protective mechanism of GBE50 against PF remains to be elucidated.

METHODS

C57BL/6J mice were treated with bleomycin (Bleo) to induce PF in the presence or absence of GBE50. Protein content in bronchoalveolar lavage fluid (BALF) and wet weight/dry weight ratio were examined for analysis of pulmonary edema. Hematoxylin-eosin staining and Masson trichrome staining were used for histopathological observation of murine lung tissues. Ashcroft score was used for semi-quantitation of lung fibrosis degree. RT-qPCR was utilized for assessing mRNA levels of pro-fibrotic mediators in lung tissues. TUNEL staining was implemented for cell apoptosis assessment. The levels of oxidative stress- and inflammation-related markers were evaluated by corresponding commercial assay kits. Western blotting was used to evaluate levels of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling- and transforming growth factor (TGF)-β1/SMAD signaling-related proteins.

RESULTS

GBE50 alleviated lung injury and severity of fibrosis, reduced collagen deposition and cell apoptosis in lung tissues, and suppressed inflammatory response and oxidative stress injury in Bleo-stimulated PF mice. GBE50 activated Nrf2 signaling pathway and inactivated TGF-β1/SMAD signaling pathway in the lungs of Bleo-induced PF mice. Inhibition of Nrf2 signaling reversed GBE50-mediated inactivation of TGF-β1/SMAD signaling and attenuation of inflammation and oxidative stress in Bleo-induced PF mice.

CONCLUSION

GBE50 protects against Bleo-induced PF in mice by mitigating fibrosis, inflammation and oxidative stress via Nrf2 and TGF-β1/SMAD signaling pathways.

Nebulized milk exosomes loaded with siTGF-β1 ameliorate pulmonary fibrosis by inhibiting EMT pathway and enhancing collagen permeability

Pulmonary Fibrosis (PF) is a fatal disease in the interstitial lung associated with high mortality, morbidity, and poor prognosis. Transforming growth factor-β1 (TGF-β1) is a fibroblast-activating protein that promotes fibrous diseases. Herein, an inhalable system was first developed using milk exosomes (M-Exos) encapsulating siRNA against TGF-β1 (MsiTGF-β1), and their therapeutic potential for bleomycin (BLM)-induced PF was investigated. M-siTGF-β1 was introduced into the lungs of mice with PF through nebulization. The collagen penetration effect and lysosomal escape ability were verified in vitro. Inhaled MsiTGF-β1 notably alleviated inflammatory infiltration, attenuated extracellular matrix (ECM) deposition, and increased the survival rate of PF mice by 4.7-fold. M-siTGF-β1 protected lung tissue from BLM toxicity by efficiently delivering specific siRNA to the lungs, leading to TGF-β1 mRNA silencing and epithelial mesenchymal transition pathway inhibition. Therefore, M-siTGF-β1 offers a promising avenue for therapeutic intervention in fibrosis-related disorders.

Construction of the pulmonary bio-adhesive delivery system of nintedanib nanocrystalline for effective treatment of pulmonary fibrosis

Pulmonary fibrosis (PF) is a chronic, progressive, and fatal lung disease with a high mortality rate. Nintedanib, as a multi-tyrosine kinase inhibitor, is widely used as the first line drug for PF patients. However, only nintedanib oral formulations are used currently in clinic and show a low drug selectivity, significant first-pass effect and low bioavailability with 4.7%, thus limiting the clinical outcome of nintedanib. In this study, nintedanib was prepared in the form of nintedanib nanocrystalline (Nib-NC) and then encapsulated with hyaluronic acid (HA) to construct a nanocrystalline-in-adhesive delivery system Nib-NC@HA with high drug loading efficacy and pulmonary bio-adhesive properties, which could avoid the first-pass effects, increase the bioavailability and reduce the systemic side effects of nintedanib. After inhalation administration of Nib-NC@HA, due to the bio-adhesive properties of HA, Nib-NC@HA could prolong the retention time of drug in the lungs and inhibit the expression of inflammation associated factors such as IL-6, IL-1β and TNF-α in lung tissue, reduce the release of pro-fibrotic growth factor, and improve the lung function, thus showing enhanced anti-fibrotic effect than Nib-NC. The results suggested that Nib-NC@HA is an efficient and optimal targeted bio-adhesive delivery system for the lungs to treat pulmonary fibrosis.

Targeting CEBPA to restore cellular identity and tissue homeostasis in pulmonary fibrosis

Fibrosis in the lung is thought to be driven by epithelial cell dysfunction and aberrant cell-cell interactions. Unveiling the molecular mechanisms of cellular plasticity and cell-cell interactions is imperative to elucidating lung regenerative capacity and aberrant repair in pulmonary fibrosis. By mining publicly available RNA-Seq data sets, we identified loss of CCAAT enhancer-binding protein alpha (CEBPA) as a candidate contributor to idiopathic pulmonary fibrosis (IPF). We used conditional KO mice, scRNA-Seq, lung organoids, small-molecule inhibition, and potentially novel gene manipulation methods to investigate the role of CEBPA in lung fibrosis and repair. Long-term (6 months or more) of Cebpa loss in AT2 cells caused spontaneous fibrosis and increased susceptibility to bleomycin-induced fibrosis. Cebpa knockout (KO) in these mice significantly decreased AT2 cell numbers in the lung and reduced expression of surfactant homeostasis genes, while increasing inflammatory cell recruitment as well as upregulating S100a8/a9 in AT2 cells. In vivo treatment with an S100A8/A9 inhibitor alleviated experimental lung fibrosis. Restoring CEBPA expression in lung organoids ex vivo and during experimental lung fibrosis in vivo rescued CEBPA deficiency-mediated phenotypes. Our study establishes a direct mechanistic link between CEBPA repression, impaired AT2 cell identity, disrupted tissue homeostasis, and lung fibrosis.

Ovarian fibrosis: molecular mechanisms and potential therapeutic targets

Ovarian fibrosis, characterized by the excessive proliferation of ovarian fibroblasts and the accumulation of extracellular matrix (ECM), serves as one of the primary causes of ovarian dysfunction. Despite the critical role of ovarian fibrosis in maintaining the normal physiological function of the mammalian ovaries, research on this condition has been greatly underestimated, which leads to a lack of clinical treatment options for ovarian dysfunction caused by fibrosis. This review synthesizes recent research on the molecular mechanisms of ovarian fibrosis, encompassing TGF-β, extracellular matrix, inflammation, and other profibrotic factors contributing to abnormal ovarian fibrosis. Additionally, we summarize current treatment approaches for ovarian dysfunction targeting ovarian fibrosis, including antifibrotic drugs, stem cell transplantation, and exosomal therapies. The purpose of this review is to summarize the research progress on ovarian fibrosis and to propose potential therapeutic strategies targeting ovarian fibrosis for the treatment of ovarian dysfunction.

Selpercatinib attenuates bleomycin-induced pulmonary fibrosis by inhibiting the TGF-β1 signaling pathway

IPF is a chronic, progressive, interstitial lung disease with high mortality. Current drugs have limited efficacy in curbing disease progression and improving quality of life. Selpercatinib, a highly selective inhibitor of receptor tyrosine kinase RET (rearranged during transfection), was approved in 2020 for the treatment of a variety of solid tumors with RET mutations. In this study, the action and mechanism of Selpercatinib in pulmonary fibrosis were evaluated in vivo and in vitro. In vivo experiments demonstrated that Selpercatinib significantly ameliorated bleomycin (BLM)-induced pulmonary fibrosis in mice. In vitro, Selpercatinib inhibited the proliferation, migration, activation and extracellular matrix deposition of fibroblasts by inhibiting TGF-β1/Smad and TGF-β1/non-Smad pathway, and suppressed epithelial-mesenchymal transition (EMT) like process of lung epithelial cells via inhibiting TGF-β1/Smad pathway. The results of in vivo pharmacological tests corroborated the results obtained from the in vitro experiments. Further studies revealed that Selpercatinib inhibited abnormal phenotypes of lung fibroblasts and epithelial cells in part by regulating its target RET. In short, Selpercatinib inhibited the activation of fibroblasts and EMT-like process of lung epithelial cells by inhibiting TGF-β1/Smad and TGF-β1/non-Smad pathways, thus alleviating BLM-induced pulmonary fibrosis in mice.

Abemaciclib-induced epithelial-mesenchymal transition mediated by cyclin-dependent kinase 4/6 independent of cell cycle arrest pathway

Abemaciclib (ABM), a cyclin-dependent kinase 4/6 inhibitor, shows pharmacological effects in cell cycle arrest. Epithelial-mesenchymal transition is an important cellular event associated with pathophysiological states such as organ fibrosis and cancer progression. In the present study, we evaluated the contribution of factors associated with cell cycle arrest to ABM-induced epithelial-mesenchymal transition. Treatment with 0.6 µM ABM induced both cell cycle arrest and epithelial-mesenchymal transition-related phenotypic changes. Interestingly, the knockdown of cyclin-dependent kinase 4/6, pharmacological targets of ABM or cyclin D1, which forms complexes with cyclin-dependent kinase 4/6, resulted in cell cycle arrest at the G1-phase and induction of epithelial-mesenchymal transition, indicating that downregulation of cyclin-dependent kinase 4/6-cyclin D1 complexes would mimic ABM. In contrast, knockdown of the Rb protein, which is phosphorylated by cyclin-dependent kinase 4/6, had no effect on the expression level of α-smooth muscle actin, an epithelial-mesenchymal transition marker. Furthermore, ABM-induced epithelial-mesenchymal transition was not affected by Rb knockdown, suggesting that Rb is not involved in the transition process. Our study is the first to suggest that cyclin-dependent kinase 4/6-cyclin D1 complexes, as pharmacological targets of ABM, may contribute to ABM-induced epithelial-mesenchymal transition, followed by clinical disorders such as organ fibrosis and cancer progression. This study suggests that blocking epithelial-mesenchymal transition might be a promising way to prevent negative side effects caused by a medication (ABM) without affecting its ability to treat the disease.

Nebivolol ameliorates sepsis-evoked kidney dysfunction by targeting oxidative stress and TGF-β/Smad/p53 pathway

Sepsis is a potential fetal organ destruction brought on through an overzealous immunologic reaction to infection, causing severe inflammation, septic shock, and damage to different organs. Although there has been progress in the identification and controlling of clinical sepsis, the fatality rates are still significant. This study, for the first time, intended to examine the possible ameliorative impact of Nebivolol, a β1-adrenergic antagonist antihypertensive drug, against nephrotoxicity resulted from cecal ligation and puncture (CLP)-induced sepsis in rats, on molecular basis. Sixty male Wistar albino rats were chosen. Oxidative stress indicators and biochemical markers of kidney activity were evaluated. Inflammatory mediators, fibrosis- and apoptosis-related proteins and gene expressions were investigated. Moreover, renal histopathological investigation was performed. CLP-induced nephrotoxicity characterized by markedly elevated serum levels of creatinine, blood urea nitrogen, uric acid, and renal malondialdhyde. On the other hand, it decreased serum total protein level, renal superoxide dismutase activity and reduced glutathione level. Additionally, it significantly elevated the renal inflammatory mediators (tumor necrosis factor-alpha, ilnerlukin (IL)-6, and IL-1β) and Caspase-3 protein, reduced IL-10 level, amplified the expression of transforming growth factor-beta 1 (TGF-β1), p-Smad2/3 and alpha-smooth-muscle actin proteins, downregulated the B cell lymphoma-2 (Bcl-2) gene and elevated the transcription of Bcl-2-associated X-protein (Bax), p53 and Nuclear factor-kappa B (NF-κB) genes. Furtheremor, kidney tissues exhibited significant histopathological changes with CLP. On the contrary, Nebivolol significantly improved all these biochemical changes and enhanced the histopathological alterations obtained by CLP. This research showed, for the first time, that Nebivolol effectively mitigated the CLP-induced kidney dysfunction via its antioxidant, antifibrotic and anti-apoptotic activity through modulation of oxidative stress, TGF-β/NF-κB and TGF-β/Smad/p53 signaling pathways.

Stem cell-based therapy for fibrotic diseases: mechanisms and pathways

Fibrosis is a pathological process, that could result in permanent scarring and impairment of the physiological function of the affected organ; this condition which is categorized under the term organ failure could affect various organs in different situations. The involvement of the major organs, such as the lungs, liver, kidney, heart, and skin, is associated with a high rate of morbidity and mortality across the world. Fibrotic disorders encompass a broad range of complications and could be traced to various illnesses and impairments; these could range from simple skin scars with beauty issues to severe rheumatologic or inflammatory disorders such as systemic sclerosis as well as idiopathic pulmonary fibrosis. Besides, the overactivation of immune responses during any inflammatory condition causing tissue damage could contribute to the pathogenic fibrotic events accompanying the healing response; for instance, the inflammation resulting from tissue engraftment could cause the formation of fibrotic scars in the grafted tissue, even in cases where the immune system deals with hard to clear infections, fibrotic scars could follow and cause severe adverse effects. A good example of such a complication is post-Covid19 lung fibrosis which could impair the life of the affected individuals with extensive lung involvement. However, effective therapies that halt or slow down the progression of fibrosis are missing in the current clinical settings. Considering the immunomodulatory and regenerative potential of distinct stem cell types, their application as an anti-fibrotic agent, capable of attenuating tissue fibrosis has been investigated by many researchers. Although the majority of the studies addressing the anti-fibrotic effects of stem cells indicated their potent capabilities, the underlying mechanisms, and pathways by which these cells could impact fibrotic processes remain poorly understood. Here, we first, review the properties of various stem cell types utilized so far as anti-fibrotic treatments and discuss the challenges and limitations associated with their applications in clinical settings; then, we will summarize the general and organ-specific mechanisms and pathways contributing to tissue fibrosis; finally, we will describe the mechanisms and pathways considered to be employed by distinct stem cell types for exerting anti-fibrotic events.

Single-cell combined with transcriptome sequencing to explore the molecular mechanism of cell communication in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a common, chronic, and progressive lung disease that severely impacts human health and survival. However, the intricate molecular underpinnings of IPF remains elusive. This study aims to delve into the nuanced molecular interplay of cellular interactions in IPF, thereby laying the groundwork for innovative therapeutic approaches in the clinical field of IPF. Sophisticated bioinformatics methods were employed to identify crucial biomarkers essential for the progression of IPF. The GSE122960 single-cell dataset was obtained from the Gene Expression Omnibus (GEO) compendium, and intercellular communication potentialities were scrutinized via CellChat. The random survival forest paradigm was established using the GSE70866 dataset. Quintessential genes were selected through Kaplan-Meier (KM) curves, while immune infiltration examinations, functional enrichment critiques and nomogram paradigms were inaugurated. Analysis of intercellular communication revealed an intimate potential connections between macrophages and various cell types, pinpointing five cardinal genes influencing the trajectory and prognosis of IPF. The nomogram paradigm, sculpted from these seminal genes, exhibits superior predictive prowess. Our research meticulously identified five critical genes, confirming their intimate association with the prognosis, immune infiltration and transcriptional governance of IPF. Interestingly, we discerned these genes' engagement with the EPITHELIAL_MESENCHYMAL_TRANSITION signalling pathway, which may enhance our understanding of the molecular complexity of IPF.

Revisiting airway epithelial dysfunction and mechanisms in chronic obstructive pulmonary disease: the role of mitochondrial damage

Chronic exposure to environmental hazards causes airway epithelial dysfunction, primarily impaired physical barriers, immune dysfunction, and repair or regeneration. Impairment of airway epithelial function subsequently leads to exaggerated airway inflammation and remodeling, the main features of chronic obstructive pulmonary disease (COPD). Mitochondrial damage has been identified as one of the mechanisms of airway abnormalities in COPD, which is closely related to airway inflammation and airflow limitation. In this review, we evaluate updated evidence for airway epithelial mitochondrial damage in COPD and focus on the role of mitochondrial damage in airway epithelial dysfunction. In addition, the possible mechanism of airway epithelial dysfunction mediated by mitochondrial damage is discussed in detail, and recent strategies related to airway epithelial-targeted mitochondrial therapy are summarized. Results have shown that dysregulation of mitochondrial quality and oxidative stress may lead to airway epithelial dysfunction in COPD. This may result from mitochondrial damage as a central organelle mediating abnormalities in cellular metabolism. Mitochondrial damage mediates procellular senescence effects due to mitochondrial reactive oxygen species, which effectively exacerbate different types of programmed cell death, participate in lipid metabolism abnormalities, and ultimately promote airway epithelial dysfunction and trigger COPD airway abnormalities. These can be prevented by targeting mitochondrial damage factors and mitochondrial transfer. Thus, because mitochondrial damage is involved in COPD progression as a central factor of homeostatic imbalance in airway epithelial cells, it may be a novel target for therapeutic intervention to restore airway epithelial integrity and function in COPD.

Anoikis and SPP1 in idiopathic pulmonary fibrosis: integrating bioinformatics, cell, and animal studies to explore prognostic biomarkers and PI3K/AKT signaling regulation

OBJECTIVE

This study aims to explore the relevance of anoikis in idiopathic pulmonary fibrosis (IPF) and identify associated biomarkers and signaling pathways.

METHOD

Unsupervised consensus cluster analysis was employed to categorize IPF patients into subtypes. We utilized Weighted Gene Co-Expression Network Analysis (WGCNA) and Protein-Protein Interaction network construction to identify anoikis-related modules and key genes. A prognostic signature was developed using Lasso and multivariate Cox regression analysis. Single-cell sequencing assessed hub gene expression in various cell types, and both cell and animal experiments confirmed IPF-related pathways.

RESULTS

We identified two distinct anoikis-associated subtypes with differing prognoses. WGCNA revealed essential hub genes, with SPP1 being prominent in the anoikis-related signature. The anoikis-related signature is effective in determining the prognosis of patients with IPF. Single-cell sequencing highlighted significant differences in SPP1 expression, notably elevated in fibroblasts derived from IPF patients. In vivo and in vitro experiments demonstrated that SPP1 enhances fibrosis in mouse lung fibroblasts by regulating p27 through the PI3K/Akt pathway.

CONCLUSION

Our research demonstrates a robust prognostic signature associated with anoikis and highlights SPP1 as a pivotal regulator of the PI3K/AKT signaling pathway in pulmonary fibrosis.

Inhibition of SMYD2 attenuates paraquat-induced pulmonary fibrosis by inhibiting the epithelial-mesenchymal transition through the GLIPR2/ERK/p38 axis

Paraquat (PQ) poisoning leads to irreversible fibrosis in the lungs with high mortality and no known antidote. In this study, we investigated the effect of the SET and MYND domain containing 2 (SMYD2) on PQ-induced pulmonary fibrosis (PF) and its potential mechanisms. We established an in vivo PQ-induced PF mouse model by intraperitoneal injection of PQ (20 mg/kg) and in vitro PQ (25 μM)-injured MLE-12 cell model. On the 15th day of administration, tissue injury, inflammation, and fibrosis in mice were evaluated using various methods including routine blood counts, blood biochemistry, blood gas analysis, western blotting, H&E staining, ELISA, Masson staining, and immunofluorescence. The findings indicated that AZ505 administration mitigated tissue damage, inflammation, and collagen deposition in PQ-poisoned mice. Mechanistically, both in vivo and in vitro experiments revealed that AZ505 treatment suppressed the PQ-induced epithelial-mesenchymal transition (EMT) process by downregulating GLI pathogenesis related 2 (GLIPR2) and ERK/p38 pathway. Further investigations demonstrated that SMYD2 inhibition decreased GLIPR2 methylation and facilitated GLIPR2 ubiquitination, leading to GLIPR2 destabilization in PQ-exposed MLE-12 cells. Moreover, rescue experiments conducted in vitro demonstrated that GLIPR2 overexpression eliminated the inhibitory effect of AZ505 on the ERK/p38 pathway and EMT. Our results reveal that the SMYD2 inhibitor AZ505 may act as a novel therapeutic candidate to suppress the EMT process by modulating the GLIPR2/ERK/p38 axis in PQ-induced PF.

Sinomenine attenuates pulmonary fibrosis by downregulating TGF-β1/Smad3, PI3K/Akt and NF-κB signaling pathways

BACKGROUND

Since COVID-19 became a global epidemic disease in 2019, pulmonary fibrosis (PF) has become more prevalent among persons with severe infections, with IPF being the most prevalent form. In traditional Chinese medicine, various disorders are treated using Sinomenine (SIN). The SIN's strategy for PF defense is unclear.

METHODS

Bleomycin (BLM) was used to induce PF, after which inflammatory factors, lung histological alterations, and the TGF-/Smad signaling pathway were assessed. By administering various dosages of SIN and the TGF- receptor inhibitor SB-431,542 to human embryonic lung fibroblasts (HFL-1) and A549 cells, we were able to examine proliferation and migration as well as the signaling molecules implicated in Epithelial-Mesenchymal Transition (EMT) and Extra-Cellular Matrix (ECM).

RESULTS

In vivo, SIN reduced the pathological changes in the lung tissue induced by BLM, reduced the abnormal expression of inflammatory cytokines, and improved the weight and survival rate of mice. In vitro, SIN inhibited the migration and proliferation by inhibiting TGF-β1/Smad3, PI3K/Akt, and NF-κB pathways, prevented the myofibroblasts (FMT) of HFL-1, reversed the EMT of A549 cells, restored the balance of matrix metalloenzymes, and reduced the expression of ECM proteins.

CONCLUSION

SIN attenuated PF by down-regulating TGF-β/Smad3, PI3K/Akt, and NF-κB signaling pathways, being a potential effective drug in the treatment of PF.

Drugs targeting CTGF in the treatment of pulmonary fibrosis

Pulmonary fibrosis represents the final alteration seen in a wide variety of lung disorders characterized by increased fibroblast activity and the accumulation of substantial amounts of extracellular matrix, along with inflammatory damage and the breakdown of tissue architecture. This condition is marked by a significant mortality rate and a lack of effective treatments. The depositing of an excessive quantity of extracellular matrix protein follows the damage to lung capillaries and alveolar epithelial cells, leading to pulmonary fibrosis and irreversible damage to lung function. It has been proposed that the connective tissue growth factor (CTGF) plays a critical role in the advancement of pulmonary fibrosis by enhancing the accumulation of the extracellular matrix and exacerbating fibrosis. In this context, the significance of CTGF in pulmonary fibrosis is examined, and a summary of the development of drugs targeting CTGF for the treatment of pulmonary fibrosis is provided.

Drp1-mediated mitochondrial fission promotes pulmonary fibrosis progression through the regulation of lipid metabolic reprogramming by ROS/HIF-1α

OBJECTIVE

To confirm the mechanism of dynamic-related protein 1 (Drp1)-mediated mitochondrial fission through ROS/HIF-1α-mediated regulation of lipid metabolic reprogramming in the progression of pulmonary fibrosis (PF).

METHODS

A mouse model of PF was established by intratracheal instillation of bleomycin (BLM) (2.5 mg/kg). A PF cell model was constructed by stimulating MRC-5 cells with TGF-β (10 ng/mL). Pathological changes in the lung tissue and related protein levels were observed via tissue staining. The indicators related to lipid oxidation were detected by a kit, and lipid production was confirmed through oil red O staining. Inflammatory factors were detected by enzyme-linked immunosorbent assay (ELISA). RT-qPCR, Western blotting and immunofluorescence staining were used to detect the expression of genes and proteins related to the disease. We used CCK-8 and EdU staining to confirm cell proliferation, flow cytometry was used to confirm apoptosis and ROS levels, α-SMA expression was detected by immunofluorescence staining, and mitochondria were observed by MitoTracker staining.

RESULTS

The BLM induced lung tissue structure and alveolar wall thickening in mice. Mitochondrial fission was observed in MRC-5 cells induced by TGF-β, which led to increased cell proliferation; decreased apoptosis; increased expression of collagen, α-SMA and Drp1; and increased lipid oxidation and inflammation. Treatment with the Drp1 inhibitor mdivi-1 or transfection with si-Drp1 attenuated the induction of BLM and TGF-β. For lipid metabolism, lipid droplets were formed in BLM-induced lung tissue and in TGF-β-induced cells, fatty acid oxidation genes and lipogenesis-related genes were upregulated, ROS levels in cells were increased, and the expression of HIF-1α was upregulated. Mdivi-1 treatment reversed TGF-β induction, while H2O2 treatment or OE-HIF-1α transfection reversed the effect of mdivi-1.

CONCLUSION

In PF, inhibition of Drp1 can prevent mitochondrial fission in fibroblasts and regulate lipid metabolism reprogramming through ROS/HIF-1α; thus, fibroblast activation was inhibited, alleviating the progression of PF.

The impact of formaldehyde exposure on lung inflammatory disorders: Insights into asthma, bronchitis, and pulmonary fibrosis

Lung inflammatory disorders are a major global health burden, impacting millions of people and raising rates of morbidity and death across many demographic groups. An industrial chemical and common environmental contaminant, formaldehyde (FA) presents serious health concerns to the respiratory system, including the onset and aggravation of lung inflammatory disorders. Epidemiological studies have shown significant associations between FA exposure levels and the incidence and severity of several respiratory diseases. FA causes inflammation in the respiratory tract via immunological activation, oxidative stress, and airway remodelling, aggravating pre-existing pulmonary inflammation and compromising lung function. Additionally, FA functions as a respiratory sensitizer, causing allergic responses and hypersensitivity pneumonitis in sensitive people. Understanding the complicated processes behind formaldehyde-induced lung inflammation is critical for directing targeted strategies aimed at minimizing environmental exposures and alleviating the burden of formaldehyde-related lung illnesses on global respiratory health. This abstract explores the intricate relationship between FA exposure and lung inflammatory diseases, including asthma, bronchitis, allergic inflammation, lung injury and pulmonary fibrosis.

Design and Synthesis of Novel Ultralong-Acting Peptides as EDP-EBP Interaction Inhibitors for Pulmonary Fibrosis Treatment

The increased remodeling of the extracellular matrix (ECM) in pulmonary fibrosis (PF) generates bioactive ECM fragments called matricryptins, which include elastin-derived peptides (EDPs). The interaction between EDPs and their receptors, including elastin-binding protein (EBP), plays a crucial role in exacerbating fibrosis. Here, we present LXJ-02 for the first time, a novel ultralong-acting inhibitor that disrupts the EDPs/EBP peptide-protein interaction, promoting macrophages to secrete matrix metalloproteinase-12 (MMP-12), and showing great promise as a stable peptide. MMP-12 has traditionally been implicated in promoting inflammation and fibrosis in various acute and chronic diseases. However, we reveal a novel role of LXJ-02 that activates the macrophage-MMP-12 axis to increase MMP-12 expression and degrade ECM components like elastin. This leads to the preventing of PF while also improving EDP-EBP interaction. LXJ-02 effectively reverses PF in mouse models with minimal side effects, holding great promise as an excellent therapeutic agent for lung fibrosis.

Advances in the Study of Non-Coding RNA in the Signaling Pathway of Pulmonary Fibrosis

Pulmonary fibrosis is a group of chronic, progressive, and irreversible interstitial lung diseases, which are common to most end-stage lung diseases and are one of the most difficult diseases of the respiratory system. In recent years, due to the frequent occurrence of air pollution and smog, the incidence of pulmonary fibrosis in China has increased year by year, the morbidity and mortality rates of pulmonary fibrosis have gradually increased and the age of the disease tends to be younger. However, the pathogenesis of pulmonary fibrosis is not yet fully understood and is needed to further explore new drug targets. Studies have shown that non-coding RNAs play an important role in regulating the process of pulmonary fibrosis, non-coding RNAs and their specifically expressed can promote or inhibit the process. Here, we review the role of some in the regulation of pulmonary fibrosis signaling pathways and provide new ideas for the clinical diagnosis and treatment of pulmonary fibrosis.

Exploring therapeutic targets for molecular therapy of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis is a chronic and progressive interstitial lung disease with a poor prognosis. Idiopathic pulmonary fibrosis is characterized by repeated alveolar epithelial damage leading to abnormal repair. The intercellular microenvironment is disturbed, leading to continuous activation of fibroblasts and myofibroblasts, deposition of extracellular matrix, and ultimately fibrosis. Moreover, pulmonary fibrosis was also found as a COVID-19 complication. Currently, two drugs, pirfenidone and nintedanib, are approved for clinical therapy worldwide. However, they can merely slow the disease's progression rather than rescue it. These two drugs have other limitations, such as lack of efficacy, adverse effects, and poor pharmacokinetics. Consequently, a growing number of molecular therapies have been actively developed. Treatment options for IPF are becoming increasingly available. This article reviews the research platform, including cell and animal models involved in molecular therapy studies of idiopathic pulmonary fibrosis as well as the promising therapeutic targets and their development progress during clinical trials. The former includes patient case/control studies, cell models, and animal models. The latter includes transforming growth factor-beta, vascular endothelial growth factor, platelet-derived growth factor, fibroblast growth factor, lysophosphatidic acid, interleukin-13, Rho-associated coiled-coil forming protein kinase family, and Janus kinases/signal transducers and activators of transcription pathway. We mainly focused on the therapeutic targets that have not only entered clinical trials but were publicly published with their clinical outcomes. Moreover, this work provides an outlook on some promising targets for further validation of their possibilities to cure the disease.

The role of epithelial cells in fibrosis: Mechanisms and treatment

Fibrosis is a pathological process that affects multiple organs and is considered one of the major causes of morbidity and mortality in multiple diseases, resulting in an enormous disease burden. Current studies have focused on fibroblasts and myofibroblasts, which directly lead to imbalance in generation and degradation of extracellular matrix (ECM). In recent years, an increasing number of studies have focused on the role of epithelial cells in fibrosis. In some cases, epithelial cells are first exposed to external physicochemical stimuli that may directly drive collagen accumulation in the mesenchyme. In other cases, the source of stimulation is mainly immune cells and some cytokines, and epithelial cells are similarly altered in the process. In this review, we will focus on the multiple dynamic alterations involved in epithelial cells after injury and during fibrogenesis, discuss the association among them, and summarize some therapies targeting changed epithelial cells. Especially, epithelial mesenchymal transition (EMT) is the key central step, which is closely linked to other biological behaviors. Meanwhile, we think studies on disruption of epithelial barrier, epithelial cell death and altered basal stem cell populations and stemness in fibrosis are not appreciated. We believe that therapies targeted epithelial cells can prevent the progress of fibrosis, but not reverse it. The epithelial cell targeting therapies will provide a wonderful preventive and delaying action.

Ferroptosis Mediates Pulmonary Fibrosis: Implications for the Effect of Astragalus and Panax notoginseng Decoction

Objective

To investigate the mechanism through which Astragalus and Panax notoginseng decoction (APD) facilitates the treatment of ferroptosis-mediated pulmonary fibrosis.

Materials and Methods

First, the electromedical measurement systems were used to measure respiratory function in mice; the lungs were then collected for histological staining. Potential pharmacologic targets were predicted via network pharmacology. Finally, tests including immunohistochemistry, reverse transcription-quantitative polymerase chain reaction, and western blotting were used to evaluate the relative expression levels of collagen, transforming growth factor β, α-smooth muscle actin, hydroxyproline, and ferroptosis-related genes (GPX4, SLC7A11, ACSL4, and PTGS2) and candidates involved in the mediation of pathways associated with ferroptosis (Hif-1α and EGFR).

Results

APD prevented the occurrence of restrictive ventilation dysfunction induced by ferroptosis. Extracellular matrix and collagen fiber deposition were significantly reduced when the APD group compared with the model group; furthermore, ferroptosis was attenuated, expression of PTGS2 and ACSL4 increased, and expression of GPX4 and SLC7A11 decreased. In the APD group, the candidates related to the mediation of ferroptosis (Hif-1α and EGFR) decreased compared with the model group. Discussion and Conclusions. APD may ameliorate restrictive ventilatory dysfunction through the inhibition of ferroptosis. This was achieved through the attenuation of collagen deposition and inflammatory recruitment in pulmonary fibrosis. The underlying mechanisms might involve Hif-1α and EGFR.

Exosomal circRNAs in the plasma serve as novel biomarkers for IPF diagnosis and progression prediction

BACKGROUND

Idiopathic Pulmonary Fibrosis (IPF) is a type of chronic interstitial pneumonia, often fatal, with elusive causes and a bleak prognosis. Its treatment options are limited and largely ineffective. Early detection and precise diagnosis are pivotal in managing the disease effectively and enhancing patient survival rates. Recently, the quest for trustworthy biomarkers for IPF has gained momentum. Notably, emerging studies indicate that circular RNAs (circRNAs) found in exosomes may hold significant potential as valuable diagnostic markers.

METHODS

In this study, we initially explored the expression profile of circRNAs in exosomes sourced from the blood of IPF patients and healthy volunteers, employing a human circRNA microarray. We then utilized RT-qPCR to corroborate the dysregulated circRNAs identified by the microarray during the training phase. Next, the circRNAs that displayed a significant increase during the training phase were selected for further validation in a larger cohort encompassing 113 IPF patients and 76 healthy volunteers. Ultimately, the expression level and function of hsa_circ_0044226 were substantiated through a series of in vivo and in vitro experiments.

RESULTS

Utilizing a human circRNA microarray, we identified 11 dysregulated circRNAs in the exosomes derived from the blood of IPF patients and control volunteers. Subsequent RT-qPCR analysis revealed significant increases in three circRNAs (hsa_circ_0044226, hsa_circ_0004099, hsa_circ_0008898) within the IPF patients. Notably, hsa_circ_0044226 was markedly elevated in patients experiencing acute exacerbation of IPF (AE-IPF) compared to those with stable IPF (S-IPF). Additionally, an upregulation of hsa_circ_0044226 was observed in the blood exosomes derived from a bleomycin-induced IPF mouse model.

CONCLUSION

The expression levels of hsa_circ_0044226, hsa_circ_0004099, and hsa_circ_0008898 in plasma exosomes introduce a new paradigm of biomarkers for the diagnosis and progression of IPF.

Early Pulmonary Fibrosis-like Changes in the Setting of Heat Exposure: DNA Damage and Cell Senescence

It is well known that extreme heat events happen frequently due to climate change. However, studies examining the direct health impacts of increased temperature and heat waves are lacking. Previous reports revealed that heatstroke induced acute lung injury and pulmonary dysfunction. This study aimed to investigate whether heat exposure induced lung fibrosis and to explore the underlying mechanisms. Male C57BL/6 mice were exposed to an ambient temperature of 39.5 ± 0.5 °C until their core temperature reached the maximum or heat exhaustion state. Lung fibrosis was observed in the lungs of heat-exposed mice, with extensive collagen deposition and the elevated expression of fibrosis molecules, including transforming growth factor-β1 (TGF-β1) and Fibronectin (Fn1) (p < 0.05). Moreover, epithelial-mesenchymal transition (EMT) occurred in response to heat exposure, evidenced by E-cadherin, an epithelial marker, which was downregulated, whereas markers of EMT, such as connective tissue growth factor (CTGF) and the zinc finger transcriptional repressor protein Slug, were upregulated in the heat-exposed lung tissues of mice (p < 0.05). Subsequently, cell senescence examination revealed that the levels of both senescence-associated β-galactosidase (SA-β-gal) staining and the cell cycle protein kinase inhibitor p21 were significantly elevated (p < 0.05). Mechanistically, the cGAS-STING signaling pathway evoked by DNA damage was activated in response to heat exposure (p < 0.05). In summary, we reported a new finding that heat exposure contributed to the development of early pulmonary fibrosis-like changes through the DNA damage-activated cGAS-STING pathway followed by cellular senescence.

Tanshinone IIA alleviates bleomycin-induced pulmonary fibrosis by inhibiting Zbtb16

Pulmonary fibrosis is a complex disease that can occur in a variety of clinical settings. The Zinc Finger and BTB Domain Containing 16 (Zbtb16) is a transcription factor and has not been studied in pulmonary fibrosis. Lung tissues from rats which were treated with bleomycin and Tanshinone IIA (Tan IIA) were collected for mRNA sequencing. Zbtb16, a differentially expressed gene, was screened. Using adeno-associated virus to knock down Zbtb16 in rats, it was found that the lung index and the content of hydroxyproline in lung tissue were decreased. HE and Masson staining revealed that pathological symptoms of lung histopathology were relieved after Zbtb16 knockdown. Protein expressions of α-SMA, Collagen I and Fibronectin were significantly decreased after Zbtb16 knockdown in vivo and in vitro. Meanwhile, the protein content of TGF-β1 and the phosphorylation of Smad2/3 were inhibited by Zbtb16 knockdown. Conversely, under the treatment of Tan IIA and TGF-β1, overexpression of Zbtb16 improved cell viability, increased the expression of fibrosis-related proteins, and promoted the phosphorylation of Smad 2/3. All above demonstrates that Zbtb16 inhibition ameliorates pulmonary fibrosis and suppresses the TGF-β/Smad pathway. Furthermore, Zbtb16 mediates the inhibitory process of Tan IIA on pulmonary fibrosis. This study provides a novel candidate therapeutic target for pulmonary fibrosis.