Pulmonary fibrosis, part I: epidemiology, pathogenesis, and diagnosis

m6A reader IGF2BP1 facilitates macrophage glycolytic metabolism and fibrotic phenotype by stabilizing THBS1 mRNA to promote pulmonary fibrosis

N6-methyladenosine (m6A) modification, a dynamically reversible epigenetic mechanism, is implicated in pulmonary fibrosis (PF) progression. The function and molecular mechanisms of m6A reader, insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1) in PF remain elusive. This study investigates the mechanistic contributions of IGF2BP1 to PF development. We found IGF2BP1 was overexpressed in macrophages of PF mice. IGF2BP1 knockdown markedly attenuated bleomycin (BLM)-induced lung pathology, as evidenced by reduced inflammatory cell infiltration, fibroblast accumulation, Ashcroft fibrosis scores, and hydroxyproline deposition. Furthermore, IGF2BP1 knockdown downregulated PF-associated markers in lung tissues and embryonic lung fibroblasts (ELFs), including TGF-β1, α-SMA, Collagen-I/III, Arg1, CCL18, Ym1, CD163, IL-6, IL-1β, and TIMP1, while decreasing the CD68+/CD163+ macrophage proportion. Mechanistic studies revealed that IGF2BP1 bound to and stabilized thrombospondin-1 (THBS1) in an m6A-dependent manner. THBS1 overexpression rescued the suppression of macrophage M2 polarization caused by IGF2BP1 knockdown. Additionally, THBS1 overexpression counteracted IGF2BP1 knockdown-mediated inhibition of glycolysis, restoring HK2, LDHA, and PKM2 expression, lactate/glucose metabolism, and ATP production. Intriguingly, THBS1 physically interacted with toll-like receptor 4 (TLR4), and TLR4 overexpression reversed the inhibitory effect of THBS1 knockdown on macrophage M2 polarization and glycolytic reprogramming. Collectively, our findings demonstrate that IGF2BP1 drives PF progression by stabilizing THBS1 mRNA via m6A modification, thereby promoting TLR4-mediated macrophage M2 polarization and glycolytic activation. This study unveils a novel IGF2BP1/THBS1/TLR4 regulatory axis in PF pathogenesis, offering potential therapeutic targets.

Extraction, content determination, component analysis, and pharmacological action of Hedysari flavonoids: a review of research progress

Radix Hedysari is a traditional Chinese herbal medicine and food. It has a long history of clinical application and is used to improve health and treat various diseases. Hedysari polysaccharides, flavonoids, saponins, and alkaloids are the main components of Radix Hedysari. Hedysari flavonoids are the most important natural active ingredients in Radix Hedysari and have a variety of pharmacological effects. At present, Hedysari flavonoids have shown great application prospects in the development of drugs for the treatment of pulmonary fibrosis, osteoporosis, skeletal muscle injury, atherosclerosis, hepatic fibrosis, immune regulation, hypoglycemia, and renal fibrosis. This paper reviewed the extraction, separation, and content determination methods and chemical constituents of flavonoids from Radix Hedysari. The core electronic databases used for literature retrieval included Baidu Literature, Baidu Literature, WangFang Datas, CNKI, VIP Datas, PubMed, Google Scholar, and Web of Science. "Radix Hedysari", "Hong qi", "Flavonoid", "Hedysari Flavonoids" and "pharmacological effects", "extraction" and "structure" were used as the search terms from database creation to 30 October 2024. Multiple studies have shown that Radix Hedysari flavonoids have important pharmacological effects, such as cytotoxic effects on tumor cells, by inhibiting tumor cell growth, inducing tumor cell apoptosis, and enhancing immune function. The antioxidant effect, through the regulation of LDH, SOD, malondialdehyde and other enzymes and the expression of antioxidant-related factors, can improve osteoporosis by promoting osteoblast proliferation and differentiation, reducing calcium loss, increasing bone mineral density, maintaining bone balance and improving bone quality. These effects include reducing oxidation; preventing thrombosis; enhancing endothelial function; regulating blood lipid levels to improve anti-atherosclerosis, anti-pulmonary fibrosis and liver fibrosis performance; improving atherosclerosis; reducing skeletal muscle damage; and exerting immunomodulatory effects, such as regulating various cytokines, immune cells, immune organs and related signaling pathways. This work provides a theoretical foundation for further studies on the structure, mechanism and clinical application of Radix Hedysari flavonoids.

Modeling of lung organoid-based fibrosis for testing the sensitivity of anti-fibrotic drugs

BACKGROUND

Pulmonary fibrosis models play crucial roles in research of pulmonary fibrosis and anti-fibrosis drug screening. Despite the establishment of several pulmonary fibrosis models including lung fibrosis animals, stem cell differentiation, pulmospheres and so on, the one that mimic the personalized native lung lacks.

METHODS

We here developed a lung organoid-based fibrosis (LOF) model from native lung tissue, and the potential of the LOFs for the sensitivity test of anti-fibrotic drugs was evaluated.

RESULTS

Our results showed that the LOFs could be self-organized from the lung organoids and the fibroblasts derived from native lung tissue. Histochemical examination demonstrated that the LOFs were characteristic of pulmonary fibrosis in structure. Single-cell sequencing (SCS) further revealed that the cell clusters mimicked fibrotic process at cellular and molecular levels in the LOFs. Drug sensitivity test indicated that the LOFs could not only be used to evaluate the efficacy of anti-fibrotic drugs, but also display their toxicity.

CONCLUSIONS

We demonstrate that the LOFs represent an efficient fibrotic model that mimics faithfully the personalized characteristics of native lung tissue.

Targeted imaging of pulmonary fibrosis by a cyclic peptide LyP-1

Pulmonary fibrosis (PF) is an interstitial chronic lung disease characterized by interstitial inflammation and extracellular matrix deposition, resulting in progressive lung dysfunction and ultimate respiratory failure. However, lacking of precise and noninvasive tracers for fibrotic lesions limits timely diagnosis and treatment. Here, we identified LyP-1, a cyclic peptide, as a specific and sensitive tracer for PF detection using PET/CT imaging. FITC-LyP-1 selectively recognized fibrotic regions in bleomycin-induced PF mice, indicating its targeting capability. The colocalization of FITC-LyP-1 with extracellular collagen I within the fibrotic lesions validated its specificity, and further analysis revealed several potential target molecules. In the in vivo application studies, radiolabeled [68Ga]Ga-LyP-1 showed significantly increased lung uptake in PF mice, specifically enriching fibrotic regions on PET/CT imaging. Notably, compared to CT imaging that showed increased mean lung density throughout the phases after bleomycin-administration, lung uptake of [68Ga]Ga-LyP-1 was only increased in the later phase, indicating that LyP-1 recognizes the fibrous changes rather than the inflammatory cells in vivo. These results suggest that the new radiotracer [68Ga]Ga-LyP-1 specifically detects the extracellular matrix in fibrotic lungs. LyP-1 shows promise as a noninvasive tracer for assessing human pulmonary fibrosis, offering potential for improved diagnostic accuracy and timely intervention.

hAMSCs regulate EMT in the progression of experimental pulmonary fibrosis through delivering miR-181a-5p targeting TGFBR1

BACKGROUND

Pulmonary fibrosis (PF) is a common and multidimensional devastating interstitial lung disease. The development of novel and more effective interventions for PF is an urgent clinical need. A previous study has found that miR-181a-5p plays an important role in the development of PF, and human amniotic mesenchymal stem cells (hAMSCs) exert potent therapeutic potential on PF. However, whether hAMSCs act on PF by delivering miR-181a-5p and its detailed mechanism still remain unknown. Thus, this study was designed to investigate the underlying possible mechanism of hAMSCs on PF in bleomycin (BLM)-induced mouse PF model, and a co-culture system of hAMSCs and A549 cells epithelial mesenchymal transition (EMT) model, focusing on its effects on collagen deposition, EMT, and epithelial cell cycle regulation.

METHODS

hAMSCs with different miR-181a-5p expression levels were constructed. BLM (4 mg/kg) was used to create a PF model, while TGF-β1 was used to induce A549 cells to construct an EMT model. Furthermore, the effects of different miR-181a-5p expression in hAMSCs on collagen deposition and EMT during lung fibrosis were assessed in vivo and in vitro.

RESULTS

We found that hAMSCs exerted anti-fibrotic effect in BLM-induced mouse PF model. Moreover, hAMSCs also exerted protective effect on TGFβ1-induced A549 cell EMT model. Furthermore, hAMSCs ameliorated PF by promoting epithelial cell proliferation, reducing epithelial cell apoptosis, and attenuating EMT of epithelial cells through paracrine effects. hAMSCs regulated EMT in PF through delivering miR-181a-5p targeting TGFBR1.

CONCLUSIONS

Our findings reveal for the first time that hAMSCs inhibit PF by promoting epithelial cell proliferation, reducing epithelial cell apoptosis, and attenuating EMT. Mechanistically, the therapeutic effect of hMASCs on PF is achieved through delivering miR-181a-5p targeting TGFBR1.

SAHA inhibits lung fibroblast activation by increasing p66Shc expression epigenetically

Objectives

To investigate the effects of suberoylanilide hydroxamic acid (SAHA) on lung fibroblast activation and to examine the role of p66Shc in this process.

Methods

An in vitro pulmonary fibrosis model was established using transforming growth factor-β (TGF-β)-induced MRC-5 lung fibroblasts. The proliferation and migration capacities of MRC-5 cells, along with the expression of fibrosis-related genes, were assessed following treatment with SAHA and/or silence of p66Shc.

Results

In TGF-β-induced MRC-5 lung fibroblasts, SAHA treatment significantly inhibited cell proliferation and migration, as well as the expression of fibrosis-related genes, including collagen I and α-smooth muscle actin (SMA). Western blot and immunofluorescence assays revealed that SAHA increased p66Shc expression in both whole cells and mitochondria. Additionally, mito-SOX assay confirmed that SAHA treatment led to a marked accumulation of mitochondrial reactive oxygen species (ROS). However, silencing of p66Shc significantly reversed the aforementioned effects of SAHA on MRC-5 cells. Furthermore, chromatin immunoprecipitation (ChIP) assays demonstrated that SAHA enhanced active histone markers, H3K9Ac and H3K4Me3, in the p66Shc gene region.

Conclusions

SAHA alleviates lung fibroblast activation and migration by increasing p66Shc expression and mitochondrial ROS generation through epigenetic modifications of histone 3.

Mechanisms of mechanical stimulation in the development of respiratory system diseases

During respiration, mechanical stress can initiate biological responses that impact the respiratory system. Mechanical stress plays a crucial role in the development of the respiratory system. However, pathological mechanical stress can impact the onset and progression of respiratory diseases by influencing the extracellular matrix and cell transduction processes. In this article, we explore the mechanisms by which mechanical forces communicate with and influence cells. We outline the basic knowledge of respiratory mechanics, elucidating the important role of mechanical stimulation in influencing respiratory system development and differentiation from a microscopic perspective. We also explore the potential mechanisms of mechanical transduction in the pathogenesis and development of respiratory diseases such as asthma, lung injury, pulmonary fibrosis, and lung cancer. Finally, we look forward to new research directions in cellular mechanotransduction, aiming to provide fresh insights for future therapeutic research on respiratory diseases.

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.

Tetrahedral Framework Nucleic Acids Delivery of Pirfenidone for Anti-Inflammatory and Antioxidative Effects to Treat Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic and irreversible lung disease, and developing an effective treatment remains a challenge. The limited therapeutic options are primarily delivered by the oral route, among which pirfenidone (PFD) improves pulmonary dysfunction and patient quality of life. However, its high dose and severe side effects (dyspepsia and systemic photosensitivity) limit its clinical value. Intratracheal aerosolization is an excellent alternative method for treating lung diseases because it increases the concentration of the drug needed to reach the focal site. Tetrahedral framework nucleic acid (tFNA) is a drug delivery system with exceptional delivery capabilities. Therefore, we synthesized a PFD-tFNA (Pt) complex using tFNA as the delivery vehicle and achieved quantitative nebulized drug delivery to the lungs via micronebulizer for lung fibrosis treatment. In vivo, Pt exhibited excellent immunomodulatory capacity and antioxidant effects. Furthermore, Pt reduced mortality, gradually restored body weight and improved lung tissue structure. Similarly, Pt also exhibited superior fibrosis inhibition in an in vitro fibrosis model, as shown by the suppression of excessive fibroblast activation and epithelial-mesenchymal transition (EMT) in epithelial cells exposed to TGF-β1. Conclusively, Pt, a complex with tFNA as a transport system, could enrich the therapeutic regimen for IPF via intratracheal aerosolization inhalation.

Evaluating the impact of type 2 diabetes mellitus on pulmonary vascular function and the development of pulmonary fibrosis

The increasing prevalence of type 2 diabetes mellitus (T2DM) is a significant worldwide health concern caused by sedentary lifestyles and unhealthy diets. Beyond glycemic control, T2DM impacts multiple organ systems, leading to various complications. While traditionally associated with cardiovascular and microvascular complications, emerging evidence indicates significant effects on pulmonary health. Pulmonary vascular dysfunction and fibrosis, characterized by alterations in vascular tone and excessive extracellular matrix deposition, are increasingly recognized in individuals with T2DM. The onset of T2DM is often preceded by prediabetes, an intermediate hyperglycemic state that is associated with increased diabetes and cardiovascular disease risk. This review explores the relationship between T2DM, pulmonary vascular dysfunction and pulmonary fibrosis, with a focus on potential links with prediabetes. Pulmonary vascular function, including the roles of nitric oxide (NO), prostacyclin (PGI2), endothelin-1 (ET-1), thromboxane A2 (TxA2) and thrombospondin-1 (THBS1), is discussed in the context of T2DM and prediabetes. Mechanisms linking T2DM to pulmonary fibrosis, such as oxidative stress, dysregulated fibrotic signaling, and chronic inflammation, are explained. The impact of prediabetes on pulmonary health, including endothelial dysfunction, oxidative stress, and dysregulated vasoactive mediators, is highlighted. Early detection and intervention during the prediabetic stage may reduce respiratory complications associated with T2DM, emphasizing the importance of management strategies targeting blood glucose regulation and vascular health. More research that looks into the mechanisms underlying pulmonary complications in T2DM and prediabetes is needed.

Advanced Delivery Strategies of Nintedanib for Lung Disorders and Beyond: A Comprehensive Review

Nintedanib, a primary treatment for lung fibrosis, has gathered substantial attention due to its multifaceted potential. A tyrosine kinase inhibitor, nintedanib, inhibits multiple signalling receptors, including endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), and fibroblast growth factor receptor (FGFR) and ultimately inhibits fibroblast proliferation and differentiation. Therefore, nintedanib has been studied widely for other ailments like cancers and hepatic fibrosis, apart from lung disorders. Commercially, nintedanib is available as soft gelatin capsules for treatment against idiopathic pulmonary fibrosis. Since it has very low oral bioavailability (4.7%), high doses of a drug, such as 100-150 mg, are administered, which can cause problems of gastrointestinal irritation and hepatotoxicity. The article begins with exploring the mechanism of action of nintedanib, elucidating its complex interactions within cellular pathways that govern fibrotic processes. It also emphasizes the pharmacokinetics of nintedanib, clinical trial insights, and the limitations of conventional formulations. The article mainly focuses on the emerging landscape of nanoparticle-based carriers such as hybrid liposome-exosome, nano liquid crystals, discoidal polymeric, and magnetic systems, offering promising avenues to optimize drug targeting, address its efficacy issues and minimise adverse effects. However, none of these delivery systems are commercialised, and further research is required to ensure safety and effectiveness in clinical settings. Yet, as research progresses, these advanced delivery systems promise to revolutionise the treatment landscape for various fibrotic disorders and cancers, potentially improving patient outcomes and quality of life.

Research progress of SIRTs activator resveratrol and its derivatives in autoimmune diseases

Autoimmune diseases (AID) have emerged as prominent contributors to disability and mortality worldwide, characterized by intricate pathogenic mechanisms involving genetic, environmental, and autoimmune factors. In response to this challenge, a growing body of research in recent years has delved into genetic modifications, yielding valuable insights into AID prevention and treatment. Sirtuins (SIRTs) constitute a class of NAD-dependent histone deacetylases that orchestrate deacetylation processes, wielding significant regulatory influence over cellular metabolism, oxidative stress, immune response, apoptosis, and aging through epigenetic modifications. Resveratrol, the pioneering activator of the SIRTs family, and its derivatives have captured global scholarly interest. In the context of AID, these compounds hold promise for therapeutic intervention by modulating the SIRTs pathway, impacting immune cell functionality, suppressing the release of inflammatory mediators, and mitigating tissue damage. This review endeavors to explore the potential of resveratrol and its derivatives in AID treatment, elucidating their mechanisms of action and providing a comprehensive analysis of current research advancements and obstacles. Through a thorough examination of existing literature, our objective is to advocate for the utilization of resveratrol and its derivatives in AID treatment while offering crucial insights for the formulation of innovative therapeutic approaches.

SEMA3B inhibits TGFβ-induced extracellular matrix protein production and its reduced levels are associated with a decline in lung function in IPF

Idiopathic pulmonary fibrosis (IPF) is marked by the activation of fibroblasts, leading to excessive production and deposition of extracellular matrix (ECM) within the lung parenchyma. Despite the pivotal role of ECM overexpression in IPF, potential negative regulators of ECM production in fibroblasts have yet to be identified. Semaphorin class 3B (SEMA3B), a secreted protein highly expressed in lung tissues, has established roles in axonal guidance and tumor suppression. However, the role of SEMA3B in ECM production by fibroblasts in the pathogenesis of IPF remains unexplored. Here, we show the downregulation of SEMA3B and its cognate binding receptor, neuropilin 1 (NRP1), in IPF lungs compared with healthy controls. Notably, the reduced expression of SEMA3B and NRP1 is associated with a decline in lung function in IPF. The downregulation of SEMA3B and NRP1 transcripts was validated in the lung tissues of patients with IPF, and two alternative mouse models of pulmonary fibrosis. In addition, we show that transforming growth factor-β (TGFβ) functions as a negative regulator of SEMA3B and NRP1 expression in lung fibroblasts. Furthermore, we demonstrate the antifibrotic effects of SEMA3B against TGFβ-induced ECM production in IPF lung fibroblasts. Overall, our findings uncovered a novel role of SEMA3B in the pathogenesis of pulmonary fibrosis and provided novel insights into modulating the SEMA3B-NRP1 axis to attenuate pulmonary fibrosis.NEW & NOTEWORTHY The excessive production and secretion of collagens and other extracellular matrix proteins by fibroblasts lead to the scarring of the lung in severe fibrotic lung diseases. This study unveils an antifibrotic role for semaphorin class 3B (SEMA3B) in the pathogenesis of idiopathic pulmonary fibrosis. SEMA3B functions as an inhibitor of transforming growth factor-β-driven fibroblast activation and reduced levels of SEMA3B and its receptor, neuropilin 1, are associated with decreased lung function in idiopathic pulmonary fibrosis.

LncRNA-mediated ceRNA network reveals the mechanism of action of Saorilao-4 decoction against pulmonary fibrosis

Introduction: Pulmonary fibrosis (PF), a type of interstitial pneumonia with complex etiology and high mortality, is characterized by progressive scarring of the alveolar interstitium and myofibroblastic lesions. In this study, we screened for potential biomarkers in PF and clarified the role of the lncRNA-miRNA-mRNA ceRNA network in the inhibitory effect of SRL-4 on PF. Methods: Healthy male SPF SD rats were randomly divided into three groups, namely, CON, MOD, and SRL-4. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed to determine the biological functions of the target genes. A visualized lncRNA-miRNA-mRNA ceRNA network was constructed using Cytoscape, while key genes in the network were identified using the cytoNCA plugin. Results: Seventy-four differentially expressed lncRNAs and 118 differentially expressed mRNAs were identified. Gene Ontology analysis revealed that the target genes were mainly enriched in the cell membrane and in response to organic substances, while Kyoto Encyclopedia of Genes and Genomes analysis showed that the target genes were mainly enriched in the AMPK, PPAR, and cAMP signaling pathways. We elucidated a ceRNA axis, namely, Plcd3-OT1/rno-miR-150-3p/Fkbp5, with potential implications in PF. Key genes, such as AABR07051308.1-201, F2rl2-OT1, and LINC3337, may be important targets for the treatment of PF, while the AMPK, PPAR, and cAMP signaling pathways are potential key targets and important pathways through which SRL-4 mitigates PF. Conclusion: Our findings suggest that SRL-4 improves PF by regulating the lncRNA-miRNA-mRNA network.

Circ_0035796 depletion inhibits transforming growth factor-β1-induced pulmonary fibrosis in a miR-150-5p/L1CAM-dependent manner

BACKGROUND

The pathogenesis of pulmonary fibrosis is not fully understood. Previous work has demonstrated the important role of circular RNA (circRNA) in pulmonary fibrosis development. This study aims to analyse the role of circ_0035796 in pulmonary fibrosis and the underlying mechanism.

METHODS

Human foetal lung fibroblast 1 (HFL1) cells were treated with transforming growth factor-β1 (TGF-β1) to mimic a pulmonary fibrosis cell model. The expression of circ_0035796, microRNA-150-5p (miR-150-5p) and L1 cell adhesion molecule (L1CAM) was determined by quantitative real-time polymerase chain reaction (qRT-PCR). The protein expression of L1CAM, collagen I and fibronectin was detected by Western blot. Cell viability was analysed by CCK-8 assay. Cell proliferation, invasion and migration were investigated by 5-Ethynyl-2'-deoxyuridine (EdU) assay, transwell invasion assay and wound-healing assay, respectively. The secretion of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) was analysed by Enzyme-linked immunosorbent assay (ELISA). Oxidative stress was assessed by detecting Superoxide Dismutase (SOD) activity and Malondialdehyde (MDA) level using commercial kits. The association of miR-150-5p with circ_0035796 and L1CAM was identified by dual-luciferase reporter assay, RNA pull-down assay and RNA immunoprecipitation (RIP) assay.

RESULTS

Circ_0035796 and L1CAM expression were dramatically upregulated, while miR-150-5p expression was downregulated in TGF-β1-treated HFL1 cells. TGF-β1 treatment induced cell proliferation, migration, invasion, IL-6 and TNF-α secretion, and oxidative stress, whereas circ_0035796 depletion relieved these effects. In addition, circ_0035796 acted as a sponge of miR-150-5p and miR-150-5p combined with L1CAM. Moreover, miR-150-5p depletion attenuated circ_0035796 knockdown-mediated effects in TGF-β1-exposed HFL1 cells. The regulation of miR-150-5p on TGF-β1-induced fibroblast activation involved the downregulation of L1CAM. Further, circ_0035796 modulated L1CAM expression by interacting with miR-150-5p in TGF-β1-exposed HFL1 cells.

CONCLUSION

Circ_0035796 knockdown ameliorates TGF-β1-induced pulmonary fibrosis through the miR-150-5p/L1CAM axis in vitro.

ErbB4 promotes M2 activation of macrophages in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is the most common and fatal diffuse fibrotic lung disease accompanied by macrophage M2 activation. ErbB4 is involved in and affects the process of inflammation. In this study, we determined that the mRNA level and protein expression of ErbB4 and M2 cytokine members were increased in the serum of IPF patients. In mouse alveolar macrophage MH-S cells, after knocking down ErbB4 by siRNA, the mRNA level and protein expression of M2 activator induced by interleukin (IL)-4 were decreased compared with the control group. Activating by ErbB4 agonist neuromodulatory protein (NRG)-1, IL-4-induced M2 program was promoted. Mechanistically, treated with NRG-1 in MH-S cells, the phosphorylation level of Akt did not change, while the phosphorylation level of ERK increased. Using SCH772984 to inhibit ERK pathway, the increasing IL-4-induced M2 activation by NRG-1 was inhibited, and the high level of M2 activator protein expression and mRNA expression was restored. Collectively, our data support that ErbB4 and M2 programs are implicated in IPF, and ErbB4 participates in the regulation of M2 activation induced by IL-4 through the ERK pathway.

Idiopathic Pulmonary Fibrosis Molecular Substrates Revealed by Competing Endogenous RNA Regulatory Networks

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive fibrotic disease of the lung with poor prognosis. Fibrosis results from remodeling of the interstitial tissue. A wide range of gene expression changes are observed, but the role of micro RNAs (miRNAs) and circular RNAs (circRNA) is still unclear. Therefore, this study aimed to establish an messenger RNA (mRNA)-miRNA-circRNA competing endogenous RNA (ceRNA) regulatory network to uncover novel molecular signatures using systems biology tools. Six datasets were used to determine differentially expressed genes (DEGs) and miRNAs (DEmiRNA). Accordingly, protein-protein, mRNA-miRNA, and miRNA-circRNA interactions were constructed. Modules were determined and further analyzed in the Drug Gene Budger platform to identify potential therapeutic compounds. We uncovered common 724 DEGs and 278 DEmiRNAs. In the protein-protein interaction network, TMPRSS4, ESR2, TP73, CLEC4E, and TP63 were identified as hub protein coding genes. The mRNA-miRNA interaction network revealed two modules composed of ADRA1A, ADRA1B, hsa-miR-484 and CDH2, TMPRSS4, and hsa-miR-543. The DEmiRNAs in the modules further analyzed to propose potential circRNA regulators in the ceRNA network. These results help deepen the understanding of the mechanisms of IPF. In addition, the molecular leads reported herein might inform future innovations in diagnostics and therapeutics research and development for IPF.

Association between idiopathic pulmonary fibrosis and risk of different pathological types of lung cancer: a Mendelian randomization study

BACKGROUND

Many epidemiological studies have shown that idiopathic pulmonary fibrosis (IPF) is a risk factor for lung cancer (LC), but these studies do not provide direct evidence of a causal association between the two diseases. We investigated the causal association between IPF and different pathological types of LC based on the Mendelian randomization (MR) study.

METHODS

The genome-wide association study (GWAS) data of IPF and LC were obtained from the latest published articles, and instrumental variables (IVs) for analysis were obtained after screening and eliminating the confounders. MR Analysis was carried out with the help of random effects inverse variance weighting (re-IVW), MR-egger, and weighted median method, and a comprehensive sensitivity test was conducted.

RESULTS

The results of re-IVW analysis showed that IPF may increase the risk of lung squamous cell carcinoma (LUSC) (OR = 1.045, 95% CI 1.011 to 1.080, P = 0.008). In addition, no causal relationship was found between IPF and overall LC (OR = 0.977, 95% CI 0.933 to 1.023, P = 0.32), lung adenocarcinoma (LUAD) (OR = 0.967, 95% CI 0.903 to 1.036, P = 0.345) and small cell lung carcinoma (SCLC) (OR = 1.081, 95% CI 0.992 to 1.177, P = 0.074). A comprehensive sensitivity analysis ensured the reliability of the study.

CONCLUSION

In conclusion, from the perspective of genetic association, we found that IPF is an independent risk factor for LUSC and may increase the risk of LUSC, but no such causal relationship was found in LUAD and SCLC.

hucMSCs treatment prevents pulmonary fibrosis by reducing circANKRD42-YAP1-mediated mechanical stiffness

Idiopathic pulmonary fibrosis (IPF) is a fibrosing interstitial pneumonia of unknown cause. The most typical characteristic of IPF is gradual weakening of pulmonary elasticity and increase in hardness/rigidity with aging. This study aims to identify a novel treatment approach for IPF and explore mechanism of mechanical stiffness underlying human umbilical cord mesenchymal stem cells (hucMSCs) therapy. Target ability of hucMSCs was examined by labeling with cell membrane dye Dil. Anti-pulmonary fibrosis effect of hucMSCs therapy by reducing mechanical stiffness was evaluated by lung function analysis and MicroCT imaging system and atomic force microscope in vivo and in vitro. Results showed that stiff environment of fibrogenesis caused cells to establish a mechanical connection between cytoplasm and nucleus, initiating expression of related mechanical genes such as Myo1c and F-actin. HucMSCs treatment blocked force transmission and reduced mechanical force. For further exploration of mechanism, ATGGAG was mutated to CTTGCG (the binding site of miR-136-5p) in the full-length sequence of circANKRD42. Wildtype and mutant plasmids of circANKRD42 were packaged into adenovirus vectors and sprayed into lungs of mice. Mechanistic dissection revealed that hucMSCs treatment repressed circANKRD42 reverse splicing biogenesis by inhibiting hnRNP L, which in turn promoted miR-136-5p binds to 3'-Untranslated Region (3'-UTR) of YAP1 mRNA directly, thus inhibiting translation of YAP1 and reducing YAP1 protein entering nucleus. The condition repressed expression of related mechanical genes to block force transmission and reduce mechanical forces. The mechanosensing mechanism mediated directly by circANKRD42-YAP1 axis in hucMSCs treatment, which has potential general applicability in IPF treatment.

Veterinary radiologic error rate as determined by necropsy

A large-scale postmortem auditing of antemortem imaging diagnoses has yet to be accomplished in veterinary medicine. For this retrospective, observational, single-center, diagnostic accuracy study, necropsy reports for patients of The Schwarzman Animal Medical Center were collected over a 1-year period. Each necropsy diagnosis was determined to be either correctly diagnosed or discrepant with its corresponding antemortem diagnostic imaging, and discrepancies were categorized. The radiologic error rate was calculated to include only clinically significant missed diagnoses (lesion was not reported but was retrospectively visible on the image) and misinterpretations (lesion was noted but was incorrectly diagnosed). Nonerror discrepancies, such as temporal indeterminacy, microscopic limitations, sensitivity limitations, and study-type limitations were not included in the error rate. A total of 1099 necropsy diagnoses had corresponding antemortem imaging; 440 diagnoses were classified as major diagnoses, of which 176 were discrepant, for a major discrepancy rate of 40%, similar to reports in people. Seventeen major discrepancies were diagnoses that were missed or misinterpreted by the radiologist, for a calculated radiologic error rate of 4.6%, comparable with error rates of 3%-5% reported in people. From 2020 to 2021, nearly half of all clinically significant abnormalities noted at necropsy went undetected by antemortem imaging, though most discrepancies owed to factors other than radiologic error. Identifying common patterns of misdiagnosis and discrepancy will help radiologists refine their analysis of imaging studies to potentially reduce interpretive error.

Characterisation of changes in global genes expression in the lung of ICR mice in response to the inflammation and fibrosis induced by polystyrene nanoplastics inhalation

This study characterised the changes in global gene expression in the lung of ICR mice in response to the inflammation and fibrosis induced by the inhalation of 0.5 μm polystyrene (PS)-nanoplastics (NPs) at various concentrations (4, 8, and 16 μg/mL) for 2 weeks. The total RNA extracted from the lung tissue of NPs-inhaled mice was hybridised into oligonucleotide microarrays. Significant upregulation was detected in several inflammatory responses, including the number of immune cells in bronchoalveolar lavage fluid (BALF), the expression level of inflammatory cytokines, mucin secretion, and histopathological changes, while they accumulated average of 13.38 ± 1.0 μg/g in the lungs of the inhaled ICR mice. Similar responses were observed regarding the levels of fibrosis-related factors in the NPs-inhaled lung of ICR mice, such as pulmonary parenchymal area, expression of pro-fibrotic marker genes, and TGF-β1 downstream signalling without any significant hepatotoxicity and nephrotoxicity. In microarray analyses, 60 genes were upregulated, and 55 genes were downregulated in the lung of ICR mice during inflammation and fibrosis induced by NPs inhalation compared to the Vehicle-inhaled mice. Among these genes, many were categorised into several ontology categories, including the anatomical structure, binding, membrane, and metabolic process. Furthermore, the major genes in the upregulated categories included Igkv14-126000, Egr1, Scel, Lamb3, and Upk3b. In contrast, the major genes in the down-regulated categories were Olfr417, Olfr519, Rps16, Rap2b, and Vmn1r193. These results suggest several gene functional groups and individual genes as specific biomarkers respond to inflammation and fibrosis induced by PS-NPs inhalation in ICR mice.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43188-023-00188-y.

Qilongtian ameliorate bleomycin-induced pulmonary fibrosis in mice via inhibiting IL-17 signal pathway

Pulmonary fibrosis (PF) is a special type of pulmonary parenchymal disease, with chronic, progressive, fibrosis, and high mortality. There is a lack of safe, effective, and affordable treatment methods. Qilongtian (QLT) is a traditional Chinese prescription that is composed of Panax notoginseng, Earthworm, and Rhodiola, and shows the remarkable clinical curative effect of PF. However, the mechanism of QLT remains to be clarified. Therefore, we studied the effectivity of QLT in treating Bleomycin (BLM) induced PF mice. 36 C57BL/6 J mice were randomized into the control group, the model group, the low-, medium- and high-dose QLT group, and Pirfenidone group. After establishing a model of pulmonary fibrosis in mice, the control and model groups were infused with a normal saline solution, and the delivery group was infused with QLT. Pulmonary function in the mice from each group was detected. Pulmonary tissue morphologies and collagen deposition were stained by HE and Masson. The content of hydroxyproline (HYP) was detected by alkaline hydrolysis and the mRNA and protein expression of related genes in pulmonary tissues were detected by using q-PCR, ELISA, and Western blot. Our studies have shown that QLT significantly reduced the inflammatory injury, hydroxy-proline content, and collagen deposition of pulmonary tissue in BLM-induced PF mice and down-regulated the cytokine related to inflammation and fibrosis and PF expression on the mRNA and protein level in PF mice. To identify the mechanism of QLT, the Transcriptome was measured and the IL-17 signal pathway was screened out for further research. Further studies indicated that QLT reduced the mRNAs and protein levels of interleukin 17 (IL-17), c-c motif chemokine ligand 12 (CCL12), c-x-c motif chemokine ligand 5 (CXCL5), fos-like antigen 1 (FOSL1), matrix metalloproteinase-9 (MMP9), and amphiregulin (AREG), which are inflammation and fibrosis-related genes in the IL-17 signal pathway. The results indicated that the potential mechanism for QLT in the prevention of PF progression was by inhibiting inflammation resulting in the IL-17 signal pathway. Our study provides the novel scientific basis of QLT and represents new therapeutics for PF in clinical.

miR-155-5p/FOXO3a promotes pulmonary fibrosis in rats by mediating NLRP3 inflammasome activation

OBJECTIVE

Pulmonary fibrosis (PF) is regarded as progressive lung disease. miR-155-5p depletion exerts anti-fibrotic effects in silicotic mice. This study explored the effect and possible mechanism of miR-155-5p in PF rats, hoping to find a new target for PF management.

METHODS

Bleomycin-induced PF rat model was established. Alveolar structure and collagen fiber deposition were observed by HE and Elastica-Masson staining. Alveolitis and PF scores were evaluated using the method of Szapiel. Total collagen content was detected using the Sircol method. PF rats were intraperitoneally injected with NLRP3 inhibitor MCC950 or intravenously injected with miR-155-5p antagomir and si-FOXO3a lentivirus plasmids. Binding sites of miR-155-5p and FOXO3a were predicted using bioinformatics analysis and dual-luciferase reporter assay. The expressions of miR-155-5p, NLRP3, ASC, caspase-1, IL-1β, IL-18, and FOXO3a were detected by RT-qPCR, Western blot, and ELISA.

RESULTS

MCC950 treatment inhibited NLRP3 inflammasome, alleviated alveolar hemorrhage and alveolitis, and reduced blue collagen fiber deposition, scores of alveolitis and PF, and levels of NLRP3, ASC, caspase-1, IL-1β, and IL-18 in PF rats. miR-155-5p was elevated in lung tissues of PF rats. Inhibition of miR-155-5p downregulated levels of NLRP3, ASC, caspase-1, IL-1β, and IL-18 in lung tissues of PF rats. miR-155-5p targeted FOXO3a. miR-155-5p inhibition and silencing FOXO3a exacerbated alveolitis and PF in rats and increased levels of NLRP3, ASC, caspase-1, IL-1β, and IL-18.

CONCLUSIONS

miR-155-5p aggravated alveolitis and promoted PF by targeting FOXO3a and prompting the activation of NLRP3 inflammasome and then inducing IL-1β and IL-18 release.

Prevention of Bleomycin-Induced Pulmonary Inflammation and Fibrosis in Mice by Bilobalide

Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease. Bilobalide (BB) is a sesquiterpene isolated from Ginkgo biloba, and its role in IPF is poorly understood. Mice were intratracheally instilled with 2.5 mg/kg bleomycin (BLM) to induce IPF and then treated with 2.5, 5, and 10 mg/kg BB daily for 21 days. Treatment with BB ameliorated pathological injury and fibrosis of lung tissues in BLM-induced mice. BB suppressed BLM-induced inflammatory response in mice as demonstrated by reduced inflammatory cells counts (leukocytes, neutrophils, macrophages, and lymphocytes) and pro-inflammatory factors (CCL2 and TNF-α), as well as increased CXCL10 levels in BALF. The expression of BLM-induced hydroxyproline, LDH, and pro-fibrotic mediators including fibronectin, collagen I, α-smooth muscle actin (α-SMA), transforming growth factor (TGF)-β1, matrix metalloproteinase (MMP)-2, and MMP-9 in lung tissue was inhibited by BB treatment, and the tissue inhibitor of metalloproteinase-1 (TIMP-1) expression was increased. BB blocked the phosphorylation of JNK and NF-κB, and the nuclear translocation of NF-κB in the lung tissue of mice induced by BLM. Additionally, it abated the activation of NLRP3 inflammasome in lung tissue induced by BLM, which led to the downregulation of IL-18 and IL-1β in BALF. Our present study suggested that BB might ameliorate BLM-induced pulmonary fibrosis by inhibiting the early inflammatory response, which is probably via the inhibition of the JNK/NF-κB/NLRP3 signal pathway. Thus, BB might serve as a therapeutic potential agent for pulmonary inflammation and fibrosis.

The effects of mechanical force on fibroblast behavior in cutaneous injury

Wound healing results in the formation of scar tissue which can be associated with functional impairment, psychological stress, and significant socioeconomic cost which exceeds 20 billion dollars annually in the United States alone. Pathologic scarring is often associated with exaggerated action of fibroblasts and subsequent excessive accumulation of extracellular matrix proteins which results in fibrotic thickening of the dermis. In skin wounds, fibroblasts transition to myofibroblasts which contract the wound and contribute to remodeling of the extracellular matrix. Mechanical stress on wounds has long been clinically observed to result in increased pathologic scar formation, and studies over the past decade have begun to uncover the cellular mechanisms that underly this phenomenon. In this article, we will review the investigations which have identified proteins involved in mechano-sensing, such as focal adhesion kinase, as well as other important pathway components that relay the transcriptional effects of mechanical forces, such as RhoA/ROCK, the hippo pathway, YAP/TAZ, and Piezo1. Additionally, we will discuss findings in animal models which show the inhibition of these pathways to promote wound healing, reduce contracture, mitigate scar formation, and restore normal extracellular matrix architecture. Recent advances in single cell RNA sequencing and spatial transcriptomics and the resulting ability to further characterize mechanoresponsive fibroblast subpopulations and the genes that define them will be summarized. Given the importance of mechanical signaling in scar formation, several clinical treatments focused on reducing tension on the wound have been developed and are described here. Finally, we will look toward future research which may reveal novel cellular pathways and deepen our understanding of the pathogenesis of pathologic scarring. The past decade of scientific inquiry has drawn many lines connecting these cellular mechanisms that may lead to a map for the development of transitional treatments for patients on the path to scarless healing.

Idiopathic Pulmonary Fibrosis: What do we Know about the Role of Occupational and Environmental Determinants? A Systematic Literature Review and Meta-Analysis

The objectives of this systematic review of original articles published up until August 2021 and meta-analyses were to identify the links between occupational and non-occupational environmental exposures, types of occupations and idiopathic pulmonary fibrosis (IPF). Sixteen selected case-control studies were qualified as good level with Newcastle-Ottawa quality assessment scale. Sensitivity analyses highlighted the role of choice of control group, tobacco adjustment and diagnostic tools. Significantly increased risks of IPF were observed (OR (95%CI): for metals (1.42(1.05-1.92)), wood (OR:1.32(1.02-1.71)), and general dust (OR:1.32(1.08-1.63)) exposures. Subgroup analyses found a significantly elevated risk for: hardwood (OR:1.75 (1.13-2.70)), organic dusts (OR:1.72 (1.20-2.46)) and pesticides (OR:2.30 (1.30-4.08)), while no significant change was noted for softwoods and solvents. Smoking adjustments: general dust (1.45 (1.04-2.03)/organic dust (2.5 (1.49-4.22)/metals (1.87 (1.16-3)/wood dust OR: 1.16 (0.86-1.61)/pesticide exposure 2.4 (0.84-6.9) were calculated. Among agricultural workers, the risk was also increased (OR:2.06 (1.02-4.16)). Few environmental data were available and no significant associations detected. Thus, these meta-analyses highlighted the role of some occupational exposures in IPF occurrence. A more accurate and thorough assessment of exposures over the entire working life as well as on the duration and intensity of exposure and complex of multi-pollutant exposure is needed in future research and clinical practice.

Exosomes derived from hypoxia-induced alveolar epithelial cells stimulate interstitial pulmonary fibrosis through a HOTAIRM1-dependent mechanism

Pulmonary fibrosis is the result of various diseases with no satisfactory treatment approaches. The exosome-mediated transfer of long noncoding RNAs (lncRNAs) has been implicated in the pathological process of lung diseases. Herein, we investigated the therapeutic potential of HOTAIRM1 transferred by alveolar epithelial cell (AEC)-derived exosomes in interstitial pulmonary fibrosis (IPF) and the potential molecular mechanisms. Next-generation sequencing-based gene expression profiling was employed to identify lncRNAs related to IPF. Exosomes were isolated from hypoxia-induced AECs (AEC-exosomes) and identified before use. HOTAIRM1 expression was examined in bleomycin-induced IPF mouse models and the isolated exosomes, and the miRNA downstream of HOTAIRM1 was analyzed. HOTAIRM1 expression was increased in the lung tissues of IPF mice and AEC exosomes. HOTAIRM1 delivered by AEC-exosomes promoted the proliferation and transdifferentiation of lung fibroblasts (LFs). Mechanistically, HOTAIRM1 competitively bound to miR-30d-3p and recruited YY1 to upregulate HSF1 expression. In addition, miR-30d-3p targeted HSF1 by binding to its 3'-UTR and reduced its expression. In vivo assays confirmed the promoting effect of exosomes-HOTAIRM1 on extracellular matrix remodeling by regulating the miR-30d-3p/HSF1/YY1 axis. Overall, HOTAIRM1 loaded by AEC exosomes can accelerate IPF by disrupting miR-30d-3p-mediated inhibition of HSF1 and inducing recruitment of HSF1 by YY1. These results highlight a promising strategy to overcome IPF.

Green Tea Polyphenol (-)-Epigallocatechin-3-Gallate (EGCG): A Time for a New Player in the Treatment of Respiratory Diseases?

(-)-Epigallocatechin-3-gallate (EGCG) is a major polyphenol of green tea that possesses a wide variety of actions. EGCG acts as a strong antioxidant which effectively scavenges reactive oxygen species (ROS), inhibits pro-oxidant enzymes including NADPH oxidase, activates antioxidant systems including superoxide dismutase, catalase, or glutathione, and reduces abundant production of nitric oxide metabolites by inducible nitric oxide synthase. ECGC also exerts potent anti-inflammatory, anti-fibrotic, pro-apoptotic, anti-tumorous, and metabolic effects via modulation of a variety of intracellular signaling cascades. Based on this knowledge, the use of EGCG could be of benefit in respiratory diseases with acute or chronic inflammatory, oxidative, and fibrotizing processes in their pathogenesis. This article reviews current information on the biological effects of EGCG in those respiratory diseases or animal models in which EGCG has been administered, i.e., acute respiratory distress syndrome, respiratory infections, COVID-19, bronchial asthma, chronic obstructive pulmonary disease, lung fibrosis, silicosis, lung cancer, pulmonary hypertension, and lung embolism, and critically discusses effectiveness of EGCG administration in these respiratory disorders. For this review, articles in English language from the PubMed database were used.

Exploring Idiopathic Pulmonary Fibrosis Biomarker by Simultaneous Two-Photon Fluorescence Imaging of Cysteine and Peroxynitrite

Idiopathic pulmonary fibrosis (IPF) has been characterized as a chronic inflammatory disease that leads to irreversible damage to pulmonary function. However, there is no specific IPF biomarker that can be used to distinguish IPF and not pneumonia. Endoplasmic reticulum (ER) stress is prominent in IPF. To search for a specific biomarker of IPF, we developed two ER-targeting two-photon (TP) fluorescent probes, TP^ER-ONOO and TP^ER-Cys, for peroxynitrite (ONOO^-) and cysteine (Cys) imaging, respectively. A significant increase in Cys levels in the lungs was discovered only in mice with IPF, which implied that Cys might be an IPF biomarker candidate. Furthermore, we uncovered the mechanism of glutathione (GSH) deficiency in IPF, which was not due to Cys shortage but instead was attributable to impaired glutamate cysteine ligase and glutathione synthetase activities via ONOO^--induced post-transcriptional modification. This work has potential to provide a new method for IPF early diagnosis and drug efficacy evaluation.

Differences in the characteristics and pulmonary toxicity of nano- and micron-sized respirable coal dust

BACKGROUND

The characteristics of coal dust (CD) particles affect the inhalation of CD, which causes coal worker's pneumoconiosis (CWP). CD nanoparticles (CD-NPs, < 500 nm) and micron particles (CD-MPs, < 5 μm) are components of the respirable CD. However, the differences in physicochemical properties and pulmonary toxicity between CD-NPs and CD-MPs remain unclear.

METHODS

CD was analyzed by scanning electron microscopy, Malvern nanoparticle size potentiometer, energy dispersive spectroscopy, infrared spectroscopy, and electron paramagnetic resonance spectroscopy. CCK-8 assay, ELISA, transmission electron microscope, JC-1 staining, reactive oxygen species activity probe, calcium ion fluorescent probe, AO/EB staining, flow cytometry, and western blot were used to determine the differences between CD-NPs and CD-MPs on acute pulmonary toxicity. CCK-8, scratch healing and Transwell assay, hematoxylin-eosin and Masson staining, immunohistochemistry, immunofluorescence, and western blot were applied to examine the effects of CD-NPs and CD-MPs on pneumoconiosis.

RESULTS

Analysis of the size distribution of CD revealed that the samples had been size segregated. The carbon content of CD-NPs was greater than that of CD-MPs, and the oxygen, aluminum, and silicon contents were less. In in vitro experiments with A549 and BEAS-2B cells, CD-NPs, compared with CD-MPs, had more inflammatory vacuoles, release of pro-inflammatory cytokines (IL-6, IL-1β, TNFα) and profibrotic cytokines (CXCL2, TGFβ1), mitochondrial damage (reactive oxygen species and Ca2+ levels and decreased mitochondrial membrane potential), and cell death (apoptosis, pyroptosis, and necrosis). CD-NPs-induced fibrosis model cells had stronger proliferation, migration, and invasion than did CD-MPs. In in vivo experiments, lung coefficient, alveolar inflammation score, and lung tissue fibrosis score (mean: 1.1%, 1.33, 1.33) of CD-NPs were higher than those of CD-MPs (mean: 1.3%, 2.67, 2.67). CD-NPs accelerated the progression of pulmonary fibrosis by upregulating the expression of pro-fibrotic proteins and promoting epithelial-mesenchymal transition. The regulatory molecules involved were E-cadherin, N-cadherin, COL-1, COL-3, ZO-1, ZEB1, Slug, α-SMA, TGFβ1, and Vimentin.

CONCLUSIONS

Stimulation with CD-NPs resulted in more pronounced acute and chronic lung toxicity than did stimulation with CD-MPs. These effects included acute inflammatory response, mitochondrial damage, pyroptosis, and necrosis, and more pulmonary fibrosis induced by epithelial-mesenchymal transition.

Investigation of the Pharmacological Effect and Mechanism of Jinbei Oral Liquid in the Treatment of Idiopathic Pulmonary Fibrosis Using Network Pharmacology and Experimental Validation

Overview: Idiopathic pulmonary fibrosis (IPF) is a disease caused by many factors, eventually resulting in lung function failure. Jinbei oral liquid (JBOL) is a traditional Chinese clinical medicine used to treat pulmonary diseases. However, the pharmacological effects and mechanism of the action of JBOL on IPF remain unclear. This study investigated the protective effects and mechanism of the action of JBOL on IPF using network pharmacology analysis, followed by in vivo and in vitro experimental validation. Methods: The components of JBOL and their targets were screened using the TCMSP database. IPF-associated genes were obtained using DisGeNET and Drugbank. The common targets of JBOL and IPF were identified with the STRING database, and a protein-protein interaction (PPI) network was constructed. GO and KEGG analyses were performed. Sprague-Dawley rats were injected with bleomycin (BLM) to establish an IPF model and treated orally with JBOL at doses of 5.4, 10.8, and 21.6 ml/kg. A dose of 54 mg/kg of pirfenidone was used as a control. All rats were treated for 28 successive days. Dynamic pulmonary compliance (Cdyn), minute ventilation volume (MVV), vital capacity (VC), and lung resistance (LR) were used to evaluate the efficacy of JBOL. TGF-β-treated A549 cells were exposed to JBOL, and epithelial-to-mesenchymal transition (EMT) changes were assessed. Western blots were performed. Results: Two hundred seventy-eight compounds and 374 targets were screened, and 103 targets related to IPF were identified. Core targets, including MAPK1 (ERK2), MAPK14 (p38), JUN, IL-6, AKT, and others, were identified by constructing a PPI network. Several pathways were involved, including the MAPK pathway. Experimentally, JBOL increased the levels of the pulmonary function indices (Cdyn, MVV, and VC) in a dose-dependent manner and reduced the RL level in the BLM-treated rats. JBOL increased the epithelial marker E-cadherin and suppressed the mesenchymal marker vimentin expression in the TGF-β-treated A549 cells. The suppression of ERK1/2, JNK, and p38 phosphorylation by JBOL was validated. Conclusion: JBOL had therapeutic effects against IPF by regulating pulmonary function and EMT through a systemic network mechanism, thus supporting the need for future clinical trials of JBOL.

MiR-130a-3p Alleviates Inflammatory and Fibrotic Phases of Pulmonary Fibrosis Through Proinflammatory Factor TNF-α and Profibrogenic Receptor TGF-βRII

Pulmonary fibrosis (PF) is a progressive disease characterized by extracellular matrix (ECM) deposition that destroys the normal structure of the lung parenchyma, which is classified into two successive inflammatory and fibrotic phases. To investigate the anti-inflammatory and anti-fibrotic roles of miR-130a-3p in mice with bleomycin (BLM)-induced PF and the underlying mechanism, we performed single-cell RNA-sequencing analysis, which demonstrated that BLM increased/decreased the percentage of macrophages and fibroblasts/epithelial cells in PF lungs, respectively. The differentially expressed genes were enriched in PPAR signaling pathway and lysosome, ECM-receptor interaction and ribosome, and metabolism reaction. Time-course studies demonstrated that the inflammation-related factors increased significantly at day 7 (inflammatory phase), whereas the fibrosis-related factors increased at day 28 (fibrotic phase) after BLM exposure. Meanwhile, miR-130a-3p could ameliorate pulmonary lesions by downregulating the secretion of inflammatory cytokines (IL-1β, IL-6, TNF-α, and TGF-β1) and the deposition of ECM (α-SMA, FN, HYP, and collagen) in the inflammatory and fibrotic phase, respectively. In the LPS-induced inflammatory cell model, the upregulation of miR-130a-3p was mainly achieved by the activation of the NF-κB signaling pathway, which suppressed the proinflammatory factor TNF-α. Comparatively, the TGF-β/Smad signaling pathway was inhibited by miR-130a-3p targeting TGF-βRII in the TGF-β1-deduced fibrotic cell model. The evidence supports that miR-130a-3p exerts an anti-inflammatory and anti-fibrotic effect in BLM-induced PF, implying a potential pharmacological agent in the therapy of PF patients.

Glycine max (soy) based diet improves antioxidant defenses and prevents cell death in cadmium intoxicated lungs

Cadmium (Cd) is a toxic metal and an important environmental contaminant. We analyzed its effects on oligoelements, oxidative stress, cell death, Hsp expression and the histoarchitecture of rat lung under different diets, using animal models of subchronic cadmium intoxication. We found that Cd lung content augmented in intoxicated groups: Zn, Mn and Se levels showed modifications among the different diets, while Cu showed no differences. Lipoperoxidation was higher in both intoxicated groups. Expression of Nrf-2 and SOD-2 increased only in SoCd. GPx levels showed a trend to increase in Cd groups. CAT activity was higher in intoxicated groups, and it was higher in Soy groups vs. Casein. LDH activity in BAL increased in CasCd and decreased in both soy-fed groups. BAX/Bcl-2 semiquantitative ratio showed similar results than LDH activity, confirmed by Caspase 3 immunofluorescence. The histological analysis revealed an infiltration process in CasCd lungs, with increased connective tissue, fused alveoli and capillary fragility. Histoarchitectural changes were less severe in soy groups. Hsp27 expression increased in both intoxicated groups, while Hsp70 only augmented in SoCd. This show that a soy-diet has a positive impact upon oxidative unbalance, cell death and morphological changes induced by Cd and it could be a good alternative strategy against Cd exposure.

Elevated Serum IGFBP-2 and CTGF Levels Are Associated with Disease Activity in Patients with Dermatomyositis

Background. Insulin-like growth factor-binding proteins (IGFBPs) and connective tissue growth factor (CTGF) participate in angiogenesis. Dermatomyositis (DM) is characterized by microvasculopathy-derived skin lesions. Here, we investigated the clinical significance of serum IGFBP and CTGF levels in DM patients. Methods. In this study, 65 DM patients and 30 healthy controls were enrolled. Serum IGFBP and CTGF levels were examined by ELISA, and their correlation with clinical and laboratory findings was analyzed by Spearman’s correlation. Results. Serum IGFBP-2, IGFBP-4, and CTGF levels were higher in DM patients than in healthy controls (median (quartile): 258.9 (176.4–326.1) ng/mL vs. 167.7 (116.1–209.4) ng/mL, $p<0.0001$ ; 450.4 (327.3–631.8) ng/mL vs. 392.2 (339.0–480.2) ng/mL, $p=0.04$ ; and 45.71 (38.54–57.45) ng/mL vs. 35.52 (30.23–41.52) ng/mL, $p=0.001$ , respectively). IGFBP-2 and CTGF levels were positively correlated with cutaneous ( $r=0.257$ , $p=0.040$ and $r=0.427$ , $p=0.015$ , respectively) and global ( $r=0.380$ , $p=0.002$ and $r=0.292$ , $p=0.019$ , respectively) disease activity in DM patients. Conclusion. Serum IGFBP-2 and CTGF levels were increased in patients with DM and correlated with cutaneous and global disease activity.

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.

Neutrophil Extracellular Traps in ANCA-Associated Vasculitis and Interstitial Lung Disease: A Scoping Review

BACKGROUND

Deregulated neutrophil extracellular traps (NETs) formation is implicated in various diseases, including ANCA-associated vasculitis and pulmonary fibrosis (PF). Lung involvement is frequent in AAV, and interstitial lung diseases (ILDs) are strongly related to MPO-ANCA positivity and mainly reported in microscopic polyangiitis. The association between AAV and ILD is a strong indicator of poor prognosis and limited survival. Neutrophils, ANCA and NET interplay in PF development in AAV. This study aimed to review the literature concerning the implications of NET in lung fibrogenesis specifically focused on AAV associated with ILD, and the potential of NET as a theranostic marker.

METHODS

Through scoping review methodology, we used a descriptive thematic analysis to understand the pathogenic role of NETs in patients with AAV and pulmonary fibrosis and their further role as a theranostic marker of this disease.

RESULTS

The implications of NET in the pathogenesis of AAV and ILD, as well as an association between these two diseases, have been identified, but the underlying pathophysiological mechanisms are still unknown. The pharmacological or genetic inhibition of NET release reduces disease severity in multiple inflammatory disease models, indicating that NETs are potential therapeutic targets. In this regard, despite the lack of clinical data, we may hypothesise that an optimal management of AAV-ILD patients would require not only B-cells targeted therapy, but also NETs inhibition.

CONCLUSION

Preliminary findings seem to display a lack of efficacy of traditional immunosuppressants, such as Rituximab, in this subset of patients, while to date no patients suffering from a definite ILD have been enrolled in clinical trials. Further insights would be provided by their employment, as a combination treatment, in common clinical practice. Although we can imagine that the inhibition of NETs in patients with AAV-ILD could reduce severity and mortality, we still lack the scientific basis that could improve our understanding of the disease from a molecular point of view.

Network Pharmacology Prediction and Molecular Docking-Based Strategy to Discover the Potential Pharmacological Mechanism of Wen-Yu-Jin against Pulmonary Fibrosis in a Mouse Model

BACKGROUND

Pulmonary fibrosis (PF) is a devastating lung disease, resulting in gas exchange dysfunction until death. The two drugs approved by the FDA, pirfenidone and nintedanib, have obvious side effects. Wen-yu-jin (WYJ), one of the commonly used herbs in China, can treat respiratory diseases. The potential effects and the underlying mechanism of WYJ against PF are unclear.

PURPOSE

Employing network pharmacology, molecular docking, and in vivo and in vitro experiments to explore the potential effects and underlying mechanisms of WYJ in the treatment of PF.

METHODS

Ultra-high pressure liquid chromatography combined with linear ion trap-orbital tandem mass spectrometry (UHPLC-LTQ-orbital trap) was used to identify compounds of WYJ. We got PF-related targets and WYJ compounds-related targets from public databases and further completed critical targets exploration, network construction, and pathway analysis by network pharmacology. Molecular docking predicted binding activity of WYJ compounds and critical targets. Based on the above results, in vivo and in vitro experiments validated the potential effects and mechanisms of WYJ against PF.

RESULTS

23 major compositions of WYJ were identified based on UHPLC-LTQ-Orbitrap. According to the results of network pharmacology, STAT3, SRC, IL6, MAPK1, AKT1, EGFR, MAPK8, MAPK14, and IL1B are critical therapeutic targets. Molecular docking results showed that most of the compounds have good binding activities with critical targets. The results of in vivo and in vitro experiments showed that WYJ alleviated the process of fibrosis by targeting MAPK and STAT3 pathways.

CONCLUSION

Network pharmacology, molecular docking, and in vivo and in vitro experiments showed the potential effects and mechanisms of WYJ against PF, which provides a theoretical basis for the treatment of WYJ with PF.

GANE can Improve Lung Fibrosis by Reducing Inflammation via Promoting p38MAPK/TGF-β1/NF-κB Signaling Pathway Downregulation

There is a trend to use nanoparticles as distinct treatments for cancer treatment because they have overcome many of the limitations of traditional drug delivery systems. Gallic acid (GA) is an effective polyphenol in the treatment of tissue injuries. In this study, GA was loaded onto niosomes to produce gallic acid nanoemulsion (GANE) using a green synthesis technique. GANE's efficiency, morphology, UV absorption, release, and Fourier-transform infrared spectroscopy (FTIR) analysis were evaluated. An in vitro study was conducted on the A549 lung carcinoma cell line to determine the GANE cytotoxicity. Also, our study was extended to evaluate the protective effect of GANE against lipopolysaccharide (LPS)-induced pulmonary fibrosis in rats. GANE showed higher encapsulation efficiency and strong absorption at 280 nm. Transmission electron microscopy presented a spherical shape of the prepared nanoparticles, and FTIR demonstrated different spectra for the free gallic acid sample compared to GANE. GANE showed cytotoxicity for the A549 carcinoma lung cell line with a low IC₅₀ value. It was found that oral administration of GANE at 32.8 and 82 mg/kg.b.w. and dexamethasone (0.5 mg/kg) provided significant protection against LPS-induced pulmonary fibrosis. GANE enhanced production of superoxide dismutase, GPx, and GSH. It simultaneously reduced the MDA level. The GANE and dexamethasone, induced the production of IL-4, but suppressed TNF-α and IL-6. On the other hand, the lung p38MAPK, TGF-β1, and NF-κB gene expression was downregulated in rats administrated with GANE when compared with the LPS-treated rats. Histological studies confirmed the effective effect of GANE as it had a lung-protective effect against LPS-induced lung fibrosis. It was noticed that GANE can inhibit oxidative stress, lipid peroxidation, and cytokines and downregulate p38MAPK, TGF-β1, and NF-κB gene expression to suppress the proliferation and migration of lung fibrotic cells.

Alternation of the Autonomic Nervous System Is Associated With Pulmonary Sequelae in Patients With COVID-19 After Six Months of Discharge

Previous studies suggest that autonomic dysfunction is associated with disease severity in acute phase in patients with coronavirus disease 2019 (COVID-19). However, the association between autonomic dysfunction and pulmonary sequelae in patients with COVID-19 is unknown. We conducted a prospective study to investigate the association between autonomic dysfunction and pulmonary sequelae in patients with COVID-19 discharged for 6 months. We included 40 eligible participants and collected the following indicators: heart rate variability (HRV), pulmonary function tests (PFTs), lung X-ray computed tomography (CT), routine blood parameters, liver function parameters, and lymphocyte subsets. We found that at 6 months post-discharge, HRV still had a tight correlation with pulmonary fibrosis. There was a significant difference in HRV between patients with and without diffusion dysfunction, but HRV did not differ between patients with or without ventilatory dysfunction. Diffusion dysfunction and pulmonary fibrosis were tightly associated, and HRV index changes in patients with diffusion dysfunction had the same trend as that of patients with pulmonary fibrosis. They had a lower standard deviation of NN intervals (SDNN), the standard deviation of the average NN intervals (SDANN), and the triangular index, but a higher ratio between LF and HF power (LF/HF). In addition, WBC, neutrophils, and CD4/CD8 were correlated with pulmonary fibrosis and HRV. We concluded that autonomic dysfunction is closely associated with pulmonary fibrosis and diffusion dysfunction, and immune mechanisms may potentially contribute to this process.

Fibrosis Is a Basement Membrane-Related Disease in the Cornea: Injury and Defective Regeneration of Basement Membranes May Underlie Fibrosis in Other Organs

Every organ develops fibrosis that compromises functions in response to infections, injuries, or diseases. The cornea is a relatively simple, avascular organ that offers an exceptional model to better understand the pathophysiology of the fibrosis response. Injury and defective regeneration of the epithelial basement membrane (EBM) or the endothelial Descemet's basement membrane (DBM) triggers the development of myofibroblasts from resident corneal fibroblasts and bone marrow-derived blood borne fibrocytes due to the increased entry of TGF beta-1/-2 into the stroma from the epithelium and tears or residual corneal endothelium and aqueous humor. The myofibroblasts, and disordered extracellular matrix these cells produce, persist until the source of injury is removed, the EBM and/or DBM are regenerated, or replaced surgically, resulting in decreased stromal TGF beta requisite for myofibroblast survival. A similar BM injury-related pathophysiology can underly the development of fibrosis in other organs such as skin and lung. The normal liver does not contain traditional BMs but develops sinusoidal endothelial BMs in many fibrotic diseases and models. However, normal hepatic stellate cells produce collagen type IV and perlecan that can modulate TGF beta localization and cognate receptor binding in the space of Dissé. BM-related fibrosis is deserving of more investigation in all organs.

Feibi decoction-medicated serum inhibits lipopolysaccharide-induced inflammation in RAW264.7 cells and BMDMs

Feibi decoction (FBD) is a traditional Chinese herbal medicine and has been clinically used in the treatment of pulmonary fibrosis (PF), which is characterized by diffuse interstitial inflammation and exaggerated collagen accumulation. However, the potential mechanisms remain to be elucidated. The present study aimed to investigate the effect of FBD-medicated serum (FBDS) on lipopolysaccharide (LPS)-induced inflammation in macrophages. In RAW264.7 macrophages and bone marrow-derived macrophages (BMDMs), FBDS treatment significantly inhibited the production of pro-inflammatory cytokines induced by LPS. In addition, it was indicated that FBDS treatment suppressed the activation of NF-κB and Smad2/Smad3 following LPS treatment. Furthermore, FBDS treatment decreased the expression of transforming growth factor-β1 and chitinase-3-like protein 1. In conclusion, the results demonstrated that treatment with FBDS inhibited LPS-induced inflammation in RAW264.7 and BMDM cells. These data may improve understanding of the effect of FBD on anti-inflammation and help determine the mechanisms underlying the alleviation of PF via FBD.

Chlorogenic acid: Potential source of natural drugs for the therapeutics of fibrosis and cancer

Fibrosis and cancer is described by some epidemiological studies as chronic stages of different disease conditions typically characterized by uncontrolled accumulation of extra-cellular matrix (ECM), thereby leading to inflammation of tissues and organ (lungs, heart, liver and kidney) dysfunction. It is highly prevalent, and contributes to increased mortality rate worldwide. Currently, the therapeutical approaches involving selected medications (bemcentinib, pirfenidone and nintedanib) obtained synthetically, and used in clinical practices for fibrosis and cancer management and treatment has shown to be unsatisfactorily, especially during progressive stages of the disease. With regards to finding a more potent, effective, and promising curative for fibrosis and cancer, there is need for continuous experimental studies universally. However, phytochemical constituents’ particularly phenolic compounds [Chlorogenic acid (CGA)] obtained from coffee, and coffee beans have been predominantly utilized in experimental studies, due to its multiple pharmacological properties against various disease forms. Considering its natural source alongside minimal toxicity level, CGA, a major precursor of coffee have gained considerable attention nowadays from researchers worldwide, owing to its wide, efficacious and beneficial action against fibrosis and cancer. Interestingly, the safety of CGA has been proven. Furthermore, numerous experimental studies have also deduced massive remarkable outcomes in the use of CGA clinically, as a potential drug candidate against treatment of fibrosis and cancer. In the course of this review article, we systematically discussed the beneficial contributions of CGA with regards to its source, absorption, metabolism, mechanistic effects, and molecular mechanisms against different fibrosis and cancer categorization, which might be a prospective remedy in the future. Moreover, we also highlighted CGA (in vitro and in vivo analytical studies) defensive effects against various disorders.

Network Pharmacology and Experimental Assessment to Explore the Pharmacological Mechanism of Qimai Feiluoping Decoction Against Pulmonary Fibrosis

Pulmonary fibrosis (PF) is one of the pathologic changes in COVID-19 patients in convalescence, and it is also a potential long-term sequela in severe COVID-19 patients. Qimai Feiluoping decoction (QM) is a traditional Chinese medicine formula recommended in the Chinese national medical program for COVID-19 convalescent patients, and PF is one of its indications. Through clinical observation, QM was found to improve the clinical symptoms and pulmonary function and reduce the degree of PF of COVID-19 convalescent patients. To further explore the pharmacological mechanisms and possible active components of QM in anti-PF effect, UHPLC/Q-TOF-MS was used to analyze the composition of the QM extract and the active components that can be absorbed into the blood, leading to the identification of 56 chemical compounds and 10 active components. Then, network pharmacology was used to predict the potential mechanisms and targets of QM; it predicted that QM exerts its anti-PF effects via the regulation of the epithelial-mesenchymal transition (EMT), extracellular matrix (ECM) degradation, and TGF-β signaling pathway. Finally, TGF-β1-induced A549 cells were used to verify and explore the pharmacological effects of QM and found that QM could inhibit the proliferation of TGF-β1-induced A549 cells, attenuate EMT, and promote ECM degradation by inhibiting the TGF-β/Smad3 pathway.

Evaluating the Therapeutic Mechanisms of Selected Active Compounds in Houttuynia cordata Thunb. in Pulmonary Fibrosis via Network Pharmacology Analysis

Pulmonary fibrosis, a common outcome of pulmonary interstitial disease of various different etiologies, is one of the most important causes of respiratory failure. Houttuynia cordata Thunb. (family: Saururaceae) (H. cordata), as has been reported, is a Chinese herbal medicine commonly used to treat upper respiratory tract infection and bronchitis. Our previous study has proven that sodium houttuyfonate (an additional compound from sodium bisulfite and houttuynin) had beneficial effects in the prevention of pulmonary fibrosis (PF) induced by bleomycin (BLM) in mice. In the present study, network pharmacology was used to investigate the efficiency and potential mechanisms of H. cordata in PF treatment. Upon manual collection from the literature and databases such as TCMSP and TCM-ID, 10 known representative ingredients of H. cordata species were screened. Then, the prediction of the potential active ingredients, action targets, and signaling pathways were conducted through the Gene Ontology (GO), protein–protein interaction (PPI),and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The results of network pharmacology prediction suggested that H. cordata may act through multiple signaling pathways to alleviate PF, including the phosphatidylinositol 3-kinase-protein kinase B (PI3K/AKT) pathways, mitogen-activated protein kinase (MAPK) pathways, the tumor necrosis factor (TNF) pathways, and interleukin-17 (IL-17) signaling pathways. Molecular docking experiments showed that the chemical constituents of H. cordata had good affinity with TNF, MAPK1, and AKT1, and using lipopolysaccharide (LPS)-induced A549 cells, a model was established to verify the anti-pulmonary fibrosis effects and related mechanisms of H. cordata–relevant constituents. Finally, these evidences collectively suggest H. cordata may alleviate PF progression via PI3K/Akt, MAPK, and TNF signaling pathways and provide novel insights to verify the mechanism of H. cordata in the treatment of PF.

Effect of genotype on the disease course in idiopathic pulmonary fibrosis despite antifibrotic treatment

A genetic predisposition has been identified in 30% of idiopathic pulmonary fibrosis (IPF) cases. Although it is highly probable that the genotype affects the disease susceptibility and course in almost all patients, the specific genotype goes undetected. The aim of the present study was to explore the effects of variants of the genes encoding interleukin-4 (IL-4), mucin 5B (MUC5B), toll interacting protein (TOLLIP), surfactant protein A (SFPTA), transforming growth factor-β (TGF-β) and transporters associated with antigen processing (TAP1 and TAP2) on the course of IPF. A total of 50 patients with IPF were enrolled, and variants of these genes were assessed. Lung function at the time of diagnosis and after 6, 12 and 18 months, and the number of acute exacerbations and deaths in each observation period were measured. ANOVA was used to test the association between gene polymorphisms and the decrease in lung function. There was no significant effect of the gene polymorphisms on the outcomes of patients up to 6 months during the observation period. After 12 months, an effect of an IL-4 single nucleotide polymorphism (SNP) (rs 2070874) on patient outcomes was observed [relative risk (RR) for T allele: 5.6; 95% confidence interval (CI), 0.79-39.0; P=0.053]. The RR of progression in patients with the IL-4 SNP (rs 2243250) and the CT and TT genotypes was 4.3 (95% CI, 1.1-17.5; P=0.046). A total of 18 months after the diagnosis of IPF, an effect of the TOLLIP polymorphism on patient outcome was detected (rs 111521887; risk allele GC; RR: 7.2; 95% CI, 0.97-53.6; P=0.052). Thus, IL-4 and TOLLIP gene polymorphisms may represent disease course-modifying factors, but not drivers of IPF.

Genetic and Epidemiological Similarities, and Differences Between Postoperative Intraperitoneal Adhesion Development and Other Benign Fibro-proliferative Disorders

Intraperitoneal adhesions complicate over half of abdominal-pelvic surgeries with immediate, short, and long-term sequelae of major healthcare concern. The pathogenesis of adhesion development is similar to the pathogenesis of wound healing in all tissues, which if unchecked result in production of fibrotic conditions. Given the similarities, we explore the published literature to highlight the similarities in the pathogenesis of intra-abdominal adhesion development (IPAD) and other fibrotic diseases such as keloids, endometriosis, uterine fibroids, bronchopulmonary dysplasia, and pulmonary, intraperitoneal, and retroperitoneal fibrosis. Following a literature search using PubMed database for all relevant English language articles up to November 2020, we reviewed relevant articles addressing the genetic and epidemiological similarities and differences in the pathogenesis and pathobiology of fibrotic diseases. We found genetic and epidemiological similarities and differences between the pathobiology of postoperative IPAD and other diseases that involve altered fibroblast-derived cells. We also found several genes and single nucleotide polymorphisms that are up- or downregulated and whose products directly or indirectly increase the propensity for postoperative adhesion development and other fibrotic diseases. An understanding of the similarities in pathophysiology of adhesion development and other fibrotic diseases contributes to a greater understanding of IPAD and these disease processes. At a very fundamental level, blocking changes in the expression or function of genes necessary for the transformation of normal to altered fibroblasts may curtail adhesion formation and other fibrotic disease since this is a prerequisite for their development. Similarly, applying measures to induce apoptosis of altered fibroblast may do the same; however, apoptosis should be at a desired level to simultaneously ameliorate development of fibrotic diseases while allowing for normal healing. Scientists may use such information to develop pharmacologic interventions for those most at risk for developing these fibrotic conditions.

Mechanism of miR-204-5p in exosomes derived from bronchoalveolar lavage fluid on the progression of pulmonary fibrosis via AP1S2

Background

Exosomes are nanoscale vesicles secreted by various types of cells that are responsible for intracellular communication. Despite that bronchoalveolar lavage fluid (BALF) has been proven to involve in tumor development, more efforts are required to investigate the impact of BALF on pulmonary fibrosis (PF). This study aimed to investigate the mechanism of how exosomal miR-204-5p from BALF facilitates PF progression in rats.

Methods

PF rat model was established by intratracheal injection of bleomycin. BALF-derived exosomes (Exo) were extracted from normal and PF rats. PF-Exo (BALF-derived Exo from PF rats) and miR-204-5p antagomir were injected into rats to investigate the effect of exosomal miR-204-5p on PF. Collagen content in lung tissues of rats was assessed by Masson staining, hydroxyproline (HYP) content assay and immunohistochemistry (IHC). Primary lung fibroblasts were isolated, and treated by TGF-β1. After co-transfection of PF-Exo, miR-204-5p inhibitor and sh-AP1S2, cell proliferation, levels of miR-204-5p, fibrotic markers α-SMA and collagen 1 (Col 1), and proteins of autophagy markers LC3II, LC3I and P62 were measured. The interaction between miR-204-5p and AP1S2 was determined by bioinformatics online software TargetScan and dual-luciferase reporter assay.

Results

miR-204-5p was abundantly expressed in the PF-Exo group. PF-Exo injection potentiated PF progression and proliferation ability of lung fibroblasts in vivo and in vitro. Injection with PF-Exo and miR-204-5p antagomir significantly increased the LC3II/I ratio and decreased the HYP content, proteins of α-SMA, Col 1 and P62, collagen content in rat lung tissues of PF rats. TGF-β1 induction elevated the LC3II/LC3I ratio, suppressed the cell proliferation rate, and decreased the levels of α-SMA, Col 1 and P62. Additionally, AP1S2 was a direct target of miR-204-5p. miR-204-5p inhibitor can counteract the effect of PF-Exo in proliferation of lung fibroblasts, while sh-AP1S2 eliminated the effect of miR-204-5p inhibitor.

Conclusions

Exosomal miR-204-5p from BALF inhibits autophagy to promote the progression of PF rats by targeting AP1S2.

Fibrotic Idiopathic Interstitial Lung Disease: The Molecular and Cellular Key Players

Interstitial lung diseases (ILDs) that are known as diffuse parenchymal lung diseases (DPLDs) lead to the damage of alveolar epithelium and lung parenchyma, culminating in inflammation and widespread fibrosis. ILDs that account for more than 200 different pathologies can be divided into two groups: ILDs that have a known cause and those where the cause is unknown, classified as idiopathic interstitial pneumonia (IIP). IIPs include idiopathic pulmonary fibrosis (IPF), non-specific interstitial pneumonia (NSIP), cryptogenic organizing pneumonia (COP) known also as bronchiolitis obliterans organizing pneumonia (BOOP), acute interstitial pneumonia (AIP), desquamative interstitial pneumonia (DIP), respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), and lymphocytic interstitial pneumonia (LIP). In this review, our aim is to describe the pathogenic mechanisms that lead to the onset and progression of the different IIPs, starting from IPF as the most studied, in order to find both the common and standalone molecular and cellular key players among them. Finally, a deeper molecular and cellular characterization of different interstitial lung diseases without a known cause would contribute to giving a more accurate diagnosis to the patients, which would translate to a more effective treatment decision.