Inhibition of mast cells: a novel mechanism by which nintedanib may elicit anti-fibrotic effects

Recruitment or activation of mast cells in the liver aggravates the accumulation of fibrosis in carbon tetrachloride-induced liver injury

Liver diseases caused by viral infections, alcoholism, drugs, or chemical poisons are a significant health problem: Liver diseases are a leading contributor to mortality, with approximately 2 million deaths per year worldwide. Liver fibrosis, as a common liver disease characterized by excessive collagen deposition, is associated with high morbidity and mortality, and there is no effective treatment. Numerous studies have shown that the accumulation of mast cells (MCs) in the liver is closely associated with liver injury caused by a variety of factors. This study investigated the relationship between MCs and carbon tetrachloride (CCl4)-induced liver fibrosis in rats and the effects of the MC stabilizers sodium cromoglycate (SGC) and ketotifen (KET) on CCl4-induced liver fibrosis. The results showed that MCs were recruited or activated during CCl4-induced liver fibrosis. Coadministration of SCG or KET alleviated the liver fibrosis by decreasing SCF/c-kit expression, inhibiting the TGF-β1/Smad2/3 pathway, depressing the HIF-1a/VEGF pathway, activating Nrf2/HO-1 pathway, and increasing the hepatic levels of GSH, GSH-Px, and GR, thereby reducing hepatic oxidative stress. Collectively, recruitment or activation of MCs is linked to liver fibrosis and the stabilization of MCs may provide a new approach to the prevention of liver fibrosis.

Protective effects of microbial biosurfactants produced by Bacillus halotolerans and Candida parapsilosis on bleomycin-induced pulmonary fibrosis in mice: Impact of antioxidant, anti-inflammatory and anti-fibrotic properties via TGF-β1/Smad-3 pathway and miRNA-326

Idiopathic pulmonary fibrosis (IPF) is an irreversible disease which considered the most fatal pulmonary fibrosis. Pulmonary toxicity including IPF is the most severe adverse effect of bleomycin, the chemotherapeutic agent. Based on the fact that, exogenous surfactants could induce alveolar stabilization in many lung diseases, the aim of this study was to explore the effects of low cost biosurfactants, surfactin (SUR) and sophorolipids (SLs), against bleomycin-induced pulmonary fibrosis in mice due to their antioxidant, and anti-inflammatory properties. Surfactin and sophorolipids were produced by microbial conversion of frying oil and potato peel wastes using Bacillus halotolerans and Candida parapsilosis respectively. These biosurfactants were identified by FTIR, 1H NMR, and LC-MS/MS spectra. C57BL/6 mice were administered the produced biosurfactants daily at oral dose of 200 mg kg-1 one day after the first bleomycin dose (35 U/kg). We evaluated four study groups: Control, Bleomycin, Bleomycin+SUR, Bleomycin+SLs. After 30 days, lungs from each mouse were sampled for oxidative stress, ELISA, Western blot, histopathological, immunohistochemical analyses. Our results showed that the produced SUR and SLs reduced pulmonary oxidative stress and inflammatory response in the lungs of bleomycin induced mice as they suppressed SOD, CAT, and GST activities also reduced NF-κβ, TNF-α, and CD68 levels. Furthermore, biosurfactants suppressed the expression of TGF-β1, Smad-3, and p-JNK fibrotic signaling pathway in pulmonary tissues. Histologically, SUR and SLs protected against lung ECM deposition caused by bleomycin administration. Biosurfactants produced from microbial sources can inhibit the induced inflammatory and fibrotic responses in bleomycin-induced pulmonary fibrosis.

Pyroptosis-related signatures predict immune characteristics and prognosis in IPF

The purpose of this work was to use integrated bioinformatics analysis to screen for pyroptosis-related genes (PRGs) and possible immunological phenotypes linked to the development and course of IPF. Transcriptome sequencing datasets GSE70866, GSE47460 and GSE150910 were obtained from GEO database. From the GSE70866 database, 34 PRGs with differential expression were found in IPF as compared to healthy controls. In addition, a diagnostic model containing 4 genes PRGs (CAMP, MKI67, TCEA3 and USP24) was constructed based on LASSO logistic regression. The diagnostic model showed good predictive ability to differentiate between IPF and healthy, with ROC-AUC ranging from 0.910 to 0.997 in GSE70866 and GSE150910 datasets. Moreover, based on a combined cohort of the Freiburg and the Siena cohorts from GSE70866 dataset, we identified ten PRGs that might predict prognosis for IPF. We constructed a prognostic model that included eight PRGs (CLEC5A, TREM2, MMP1, IRF2, SEZ6L2, ADORA3, NOS2, USP24) by LASSO Cox regression and validated it in the Leuven cohort. The risk model divided IPF patients from the combined cohort into high-risk and low-risk subgroups. There were significant differences between the two subgroups in terms of IPF survival and GAP stage. There is a close correlation between leukocyte migration, plasma membrane junction, and poor prognosis in a high-risk subgroup. Furthermore, a high-risk score was associated with more plasma cells, activated NK cells, monocytes, and activated mast cells. Additionally, we identified HDAC inhibitors in the cMAP database that might be therapeutic for IPF. To summarize, pyroptosis and its underlying immunological features are to blame for the onset and progression of IPF. PRG-based predictive models and drugs may offer new treatment options for IPF.

Unraveling the mechanism of ethyl acetate extract from Prismatomeris connata Y. Z. Ruan root in treating pulmonary fibrosis: insights from bioinformatics, network pharmacology, and experimental validation

Introduction

Pulmonary fibrosis is a terminal lung disease characterized by fibroblast proliferation, extracellular matrix accumulation, inflammatory damage, and tissue structure destruction. The pathogenesis of this disease, particularly idiopathic pulmonary fibrosis (IPF), remains unknown. Macrophages play major roles in organ fibrosis diseases, including pulmonary fibrosis. The phenotype and polarization of macrophages are closely associated with pulmonary fibrosis. A new direction in research on anti-pulmonary fibrosis is focused on developing drugs that maintain the stability of the pulmonary microenvironment.

Methods

We obtained gene sequencing data and clinical information for patients with IPF from the GEO datasets GSE110147, GSE15197, GSE24988, GSE31934, GSE32537, GSE35145, GSE53845, GSE49072, GSE70864, and GSE90010. We performed GO, KEGG enrichment analysis and GSEA analysis, and conducted weighted gene co-expression network analysis. In addition, we performed proteomic analysis of mouse lung tissue. To verify the results of bioinformatics analysis and proteomic analysis, mice were induced by intratracheal instillation of bleomycin (BLM), and gavaged for 14 days after modeling. Respiratory function of mice in different groups was measured. Lung tissues were retained for histopathological examination, Western Blot and real-time quantitative PCR, etc. In addition, lipopolysaccharide, interferon-γ and interleukin-4 were used to induce RAW264.7 cells for 12h in vitro to establish macrophage inflammation and polarization model. At the same time, HG2 intervention was given. The phenotype transformation and cytokine secretion of macrophages were investigated by Western Blot, RT-qPCR and flow cytometry, etc.

Results

Through bioinformatics analysis and experiments involving bleomycin-induced pulmonary fibrosis in mice, we confirmed the importance of macrophage polarization in IPF. The analysis revealed that macrophage polarization in IPF involves a change in the phenotypic spectrum. Furthermore, experiments demonstrated high expression of M2-type macrophage-associated biomarkers and inducible nitric oxide synthase, thus indicating an imbalance in M1/M2 polarization of pulmonary macrophages in mice with pulmonary fibrosis.

Discussion

Our investigation revealed that the ethyl acetate extract (HG2) obtained from the roots of Prismatomeris connata Y. Z. Ruan exhibits therapeutic efficacy against bleomycin-induced pulmonary fibrosis. HG2 modulates macrophage polarization, alterations in the TGF-β/Smad pathway, and downstream protein expression in the context of pulmonary fibrosis. On the basis of our findings, we believe that HG2 has potential as a novel traditional Chinese medicine component for treating pulmonary fibrosis.

In vitro co-culture studies and the crucial role of fibroblast-immune cell crosstalk in IPF pathogenesis

IPF is a fatal lung disease characterized by intensive remodeling of lung tissue leading to respiratory failure. The remodeling in IPF lungs is largely characterized by uncontrolled fibrosis. Fibroblasts and their contractile phenotype the myofibroblast are the main cell types responsible for typical wound healing responses, however in IPF, these responses are aberrant and result in the overactivation of fibroblasts which contributes to the inelasticity of the lung leading to a decrease in lung function. The specific mechanisms behind IPF pathogenesis have been elusive, but recently the innate and adaptive immunity have been implicated in the fibrotic processes of the disease. In connection with this, several in vitro co-culture models have been used to investigate the specific interactions occurring between fibroblasts and immune cells and how this contributes to the pathobiology of IPF. In this review, we discuss the in vitro models that have been used to examine the abnormal interactions between fibroblasts and cells of the innate and adaptive immune system, and how these contribute to the fibrotic processes in the lungs of IPF patients.

The Role of Immune Cells in the Pathogenesis of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a devastating disease of unknown etiology with limited treatment options. The role of the immune system in IPF has received increasing attention. Uncontrolled immune responses drive the onset and progression of IPF. This article provides an overview of the role of innate immune cells (including macrophages, neutrophils, mast cells, eosinophils, dendritic cells, nature killer cells, nature kill cells and γδ T cells) and adaptive immune cells (including Th1 cells, Th2 cells, Th9 cells, Th17 cells, Th22 cells, cytotoxic T cells, B lymphocytes and Treg cells) in IPF. In addition, we review the current status of pharmacological treatments for IPF and new developments in immunotherapy. A deeper comprehension of the immune system's function in IPF may contribute to the development of targeted immunomodulatory therapies that can alter the course of the disease.

Phenotypic evaluation of mast cells in bovine mammary tissue and mastitis in the context of fibrosis

This research paper addresses the hypothesis that mast cells (MCs) contribute to the formation of mammary fibrosis. MCs are important immune regulatory and immune modulatory cells that play major roles in the inflammatory process. Since there is no detailed knowledge, this research study aimed to comparatively investigate the presence, localization, and immunophenotypes of MCs in healthy and mastitic mammary tissues. A total of 264 mammary samples were evaluated for the examination of mast cells and fibrosis. The mean mast cell number in both acute and chronic mastitis samples were very significantly higher than the control group P < 0.001). A 7.9-fold increase in the number of mast cells was found when the chronic mastitis group was compared with the control (healthy) group. Immunohistochemistry revealed presence of all three immune phenotypes in control and mastitic mammary samples (tryptase + (MCT), chymase + (MCC) and both chymase and tryptase + (MCTC). The mean MCT, MCC, and MCTC numbers in the chronic mastitis group were found to be significantly higher than the control (P < 0.001 for all three phenotypes) but did not differ significantly between control and acute mastitis samples. When the mean numbers of MCT, MCC, and MCTC in the control group and chronic mastitis group were compared, a 10.5, 7.8, and a 4.1-fold increase was observed, respectively. The amount of connective tissue was strongly increased in tissues with chronic mastitis and a 3.01-fold increase was detected compared to the control group. A statistically significant relation was also found between the amount of fibrosis and the increased number of total MCs (P < 0.001).

PTX3 shapes profibrotic immune cells and epithelial/fibroblast repair and regeneration in a murine model of pulmonary fibrosis

The long pentraxin 3 (PTX3) is protective in different pathologies but was not analyzed in-depth in Idiopathic Pulmonary Fibrosis (IPF). Here, we have explored the influence of PTX3 in the bleomycin (BLM)-induced murine model of IPF by looking at immune cells (macrophages, mast cells, T cells) and stemness/regenerative markers of lung epithelium (SOX2) and fibro-blasts/myofibroblasts (CD44) at different time points that retrace the progression of the disease from onset at day 14, to full-blown disease at day 21, to incomplete regression at day 28. We took advantage of transgenic PTX3 overexpressing mice (Tie2-PTX3) and Ptx3 null ones (PTX3-KO) in which pulmonary fibrosis was induced. Our data have shown that PTX3 overexpression in Tie2-PTX3 compared to WT or PTX3-KO: reduced CD68+ and CD163+ macrophages and the Tryptase+ mast cells during the whole experimental time; on the contrary, CD4+ T cells are consistently present on day 14 and dramatically decreased on day 21; CD8+ T cells do not show significant differences on day 14, but are significantly reduced on day 21; SOX2 is reduced on days 14 and 21; CD44 is reduced on day 21. Therefore, PTX3 could act on the proimmune and fibrogenic microenvironment to prevent fibrosis in BLM-treated mice.

Nintedanib in an elderly non-small-cell lung cancer patient with severe steroid-refractory checkpoint inhibitor-related pneumonitis: A case report and literature review

Immune checkpoint inhibitors tremendously improve cancer prognosis; however, severe-grade immune-related adverse events may cause premature death. Current recommendations for checkpoint inhibitor-related pneumonitis (CIP) treatment are mainly about immunosuppressive therapy, and anti-fibrotic agents are also needed, especially for patients with poor response to corticosteroids and a longer pneumonitis course. This is because fibrotic changes play an important role in the pathological evolution of CIP. Here, we report a case demonstrating that nintedanib is a promising candidate drug for CIP management or prevention, as it has potent anti-fibrotic efficacy and a safety profile. Moreover, nintedanib could partially inhibit tumor growth in patients with non-small-cell lung cancer, and its efficacy can be improved in combination with other anti-tumor therapies.

Prognostic value of tripartite motif (TRIM) family gene signature from bronchoalveolar lavage cells in idiopathic pulmonary fibrosis

BACKGROUND

Tripartite motif (TRIM) family genes get involved in the pathogenesis and development of various biological processes; however, the prognostic value of TRIM genes for idiopathic pulmonary fibrosis (IPF) needs to be explored.

METHODS

We acquired gene expression based on bronchoalveolar lavage (BAL) cells and clinical data of three independent IPF cohorts in the GSE70866 dataset from the Gene expression omnibus (GEO) database. Differentially expressed TRIM genes (DETGs) between IPF patients and healthy donors were identified and used to establish a risk signature by univariate and multivariate Cox regression analysis in the training cohort. The risk signature was further validated in other IPF cohorts, and compared with previously published signatures. Moreover, we performed functional enrichment analysis to explore the potential mechanisms. Eventually, the quantitative real time PCR was conducted to validate the expressions of the key genes in BAL from 12 IPF patients and 12 non-IPF controls from our institution.

RESULTS

We identified 4 DETGs including TRIM7, MEFV, TRIM45 and TRIM47 significantly associated with overall survival (OS) of IPF patients (P < 0.05). A multiple stepwise Cox regression analysis was performed to construct a 4-TRIM-gene prognostic signature. We categorized IPF patients into one low-risk group and the other high-risk group as per the average risk value of the TRIM prognostic signature in the training and validation cohorts. The IPF individuals in the low-risk group demonstrated an obvious OS advantage compared with the high-risk one (P < 0.01). The time-dependent receiver operating characteristic approach facilitated the verification of the predictive value of the TRIM prognostic signature in the training and validation cohorts, compared with other published signatures. A further investigation of immune cells and IPF survival displayed that higher proportion of resting memory CD4+ T cells and resting mast cells harbored OS advantage over lower proportion, however lower proportion of neutrophils, activated dendritic cells and activated NK cells indicated worse prognosis.

CONCLUSION

The TRIM family genes are significant for the prognosis of IPF and our signature could serve as a robust model to predict OS.

Persistent alveolar type 2 dysfunction and lung structural derangement in post-acute COVID-19

SARS-CoV-2 infection can manifest as a wide range of respiratory and systemic symptoms well after the acute phase of infection in over 50% of patients. Key questions remain on the long-term effects of infection on tissue pathology in recovered COVID-19 patients. To address these questions we performed multiplexed imaging of post-mortem lung tissue from 12 individuals who died post-acute COVID-19 (PC) and compare them to lung tissue from patients who died during the acute phase of COVID-19, or patients who died with idiopathic pulmonary fibrosis (IPF), and otherwise healthy lung tissue. We find evidence of viral presence in the lung up to 359 days after the acute phase of disease, including in patients with negative nasopharyngeal swab tests. The lung of PC patients are characterized by the accumulation of senescent alveolar type 2 cells, fibrosis with hypervascularization of peribronchial areas and alveolar septa, as the most pronounced pathophysiological features. At the cellular level, lung disease of PC patients, while distinct, shares pathological features with the chronic pulmonary disease of IPF. which may help rationalize interventions for PC patients. Altogether, this study provides an important foundation for the understanding of the long-term effects of SARS-CoV-2 pulmonary infection at the microanatomical, cellular, and molecular level.

Effect of M6A regulators on diagnosis, subtype classification, prognosis and novel therapeutic target development of idiopathic pulmonary fibrosis

Molecular biology studies show that RNA N6-methyladenosine (m6A) modifications may take part in the incidence and development of idiopathic pulmonary fibrosis (IPF). Nonetheless, the roles of m6A regulators in IPF are not fully demonstrated. In this study, 12 significant m6A regulators were filtered out between healthy controls and IPF patients using GSE33566 dataset. Random forest algorithm was used to identify 11 candidate m6A regulators to predict the incidence of IPF. The 11 candidate m6A regulators included leucine-rich PPR motif-containing protein (LRPPRC), methyltransferase-like protein 3, FTO alpha-ketoglutarate dependent dioxygenase (FTO), methyltransferase-like 14/16, zinc finger CCCH domain-containing protein 13, protein virilizer homolog, Cbl proto-oncogene like 1, fragile X messenger ribonucleoprotein 1 and YTH domain containing 1/2. A nomogram model was constructed based on 11 candidate m6A regulators and considered beneficial to IPF patients using decision curve analysis. Consensus clustering method was used to distinctly divide IPF patients into two m6A patterns (clusterA and clusterB) based on 12 significant m6A regulators. M6A scores of all IPF patients were obtained using principal component analysis to quantify the m6A patterns. Patients in clusterB had higher m6A scores than those in clusterA. Furthermore, patients in clusterB were correlated with Th17 and Treg cell infiltration, innate immunity and Th1 immunity, while those in clusterA were correlated with adaptive immunity and Th2 immunity. Patients in clusterB also had higher expressions of mesenchymal markers and regulatory factors of fibrosis but lower expressions of epithelial markers. Lastly and interestingly, two m6A regulators, LRPPRC (p = 0.011) and FTO (p = 0.042), were identified as novel prognostic genes in IPF patients for the first time using an external GSE93606 dataset. Both of them had a positive correlation with a better prognosis and may serve as therapy targets. Thus, we conducted virtual screening to discover potential drugs targeting LRPPRC and FTO in the treatment of IPF. In conclusion, m6A regulators are crucial to the onset, development and prognosis of IPF. Our study on m6A patterns may provide clues for clinical diagnosis, prognosis and targeted therapeutic drugs development for IPF.

Pleiotropic effects of DCLK1 in cancer and cancer stem cells

Doublecortin-like kinase 1 (DCLK1), a protein molecule, has been identified as a tumor stem cell marker in the cancer cells of gastrointestinal, pancreas, and human colon. DCLK1 expression in cancers, such as breast carcinoma, lung carcinoma, hepatic cell carcinoma, tuft cells, and human cholangiocarcinoma, has shown a way to target the DCLK1 gene and downregulate its expression. Several studies have discussed the inhibition of tumor cell proliferation along with neoplastic cell arrest when the DCLK1 gene, which is expressed in both cancer and normal cells, was targeted successfully. In addition, previous studies have shown that DCLK1 plays a vital role in various cancer metastases. The correlation of DCLK1 with numerous stem cell receptors, signaling pathways, and genes suggests its direct or an indirect role in promoting tumorigenesis. Moreover, the impact of DCLK1 was found to be related to the functioning of an oncogene. The downregulation of DCLK1 expression by using targeted strategies, such as embracing the use of siRNA, miRNA, CRISPR/Cas9 technology, nanomolecules, specific monoclonal antibodies, and silencing the pathways regulated by DCLK1, has shown promising results in both in vitro and in vivo studies on gastrointestinal (GI) cancers. In this review, we will discuss about the present understanding of DCLK1 and its role in the progression of GI cancer and metastasis.

Role of Mesenchymal Stem Cells and Extracellular Vesicles in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial fibrotic disease that leads to disability and death within 5 years of diagnosis. Pulmonary fibrosis is a disease with a multifactorial etiology. The concept of aberrant regeneration of the pulmonary epithelium reveals the pathogenesis of IPF, according to which repeated damage and death of alveolar epithelial cells is the main mechanism leading to the development of progressive IPF. Cell death provokes the migration, proliferation and activation of fibroblasts, which overproduce extracellular matrix, resulting in fibrotic deformity of the lung tissue. Mesenchymal stem cells (MSCs) and extracellular vesicles (EVs) are promising therapies for pulmonary fibrosis. MSCs, and EVs derived from MSCs, modulate the activity of immune cells, inhibit the expression of profibrotic genes, reduce collagen deposition and promote the repair of damaged lung tissue. This review considers the molecular mechanisms of the development of IPF and the multifaceted role of MSCs in the therapy of IPF. Currently, EVs-MSCs are regarded as a promising cell-free therapy tool, so in this review we discuss the results available to date of the use of EVs-MSCs for lung tissue repair.

Mast cells as a therapeutic target in myeloproliferative neoplasms

Mast cells have been implicated as mediators of bone marrow fibrosis and pruritus in myeloproliferative neoplasms (MPNs) with JAK2V617F or calreticulin mutations. We hypothesize that potent KIT inhibitors, already in clinical use for systemic mastocytosis, have therapeutic potential for the treatment of MPNs by directly targeting mast cells.

Dynamically upregulated mast cell CPA3 patterns in chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis

Background

The mast cell-specific metalloprotease CPA3 has been given important roles in lung tissue homeostasis and disease pathogenesis. However, the dynamics and spatial distribution of mast cell CPA3 expression in lung diseases remain unknown.

Methods

Using a histology-based approach for quantitative spatial decoding of mRNA and protein single cell, this study investigates the dynamics of CPA3 expression across mast cells residing in lungs from control subjects and patients with severe chronic obstructive pulmonary disease (COPD) or idiopathic lung fibrosis (IPF).

Results

Mast cells in COPD lungs had an anatomically widespread increase of CPA3 mRNA (bronchioles p &lt; 0.001, pulmonary vessels p &lt; 0.01, and alveolar parenchyma p &lt; 0.01) compared to controls, while granule-stored CPA3 protein was unaltered. IPF lungs had a significant upregulation of both mast cell density, CPA3 mRNA (p &lt; 0.001) and protein (p &lt; 0.05), in the fibrotic alveolar tissue. Spatial expression maps revealed altered mast cell mRNA/protein quotients in lung areas subjected to disease-relevant histopathological alterations. Elevated CPA3 mRNA also correlated to lung tissue eosinophils, CD3 T cells, and declined lung function. Single-cell RNA sequencing of bronchial mast cells confirmed CPA3 as a top expressed gene with potential links to both inflammatory and protective markers.

Conclusion

This study shows that lung tissue mast cell populations in COPD and IPF lungs have spatially complex and markedly upregulated CPA3 expression profiles that correlate with immunopathological alterations and lung function. Given the proposed roles of CPA3 in tissue homeostasis, remodeling, and inflammation, these alterations are likely to have clinical consequences.

CDK4/CDK6 Inhibitors Synergize with Midostaurin, Avapritinib, and Nintedanib in Inducing Growth Inhibition in KIT D816V+ Neoplastic Mast Cells

Simple Summary

Advanced systemic mastocytosis (AdvSM) is a rare malignant disease with a poor prognosis due to the drug resistance of neoplastic mast cells. We found that drugs targeting the cell cycle regulators CDK4 and CDK6 profoundly suppress the growth and survival of neoplastic mast cells. Furthermore, these drugs can overcome resistance against KIT D816V-targeting drugs, including midostaurin, in neoplastic mast cells. Finally, the CDK4/CDK6 inhibitors applied induced apoptosis in CD34+/CD38− stem cells in AdvSM. Based on these results, we believe that CDK4/CDK6 inhibition may be a new and interesting therapeutic approach with curative potential for AdvSM. Whether combinations of KIT D816-targeting drugs and CDK4/CDK6 inhibitors can induce long-term remission in patients with AdvSM remains to be determined in clinical trials.

Abstract

In most patients with advanced systemic mastocytosis (AdvSM), neoplastic mast cells (MC) express KIT D816V. However, despite their disease-modifying potential, KIT D816V-targeting drugs, including midostaurin and avapritinib, may not produce long-term remissions in all patients. Cyclin-dependent kinase (CDK) 4 and CDK6 are promising targets in oncology. We found that shRNA-mediated knockdown of CDK4 and CDK6 results in growth arrest in the KIT D816V⁺ MC line HMC-1.2. The CDK4/CDK6 inhibitors palbociclib, ribociclib, and abemaciclib suppressed the proliferation in primary neoplastic MC as well as in all HMC-1 and ROSA cell subclones that were examined. Abemaciclib was also found to block growth in the drug-resistant MC line MCPV-1, whereas no effects were seen with palbociclib and ribociclib. Anti-proliferative drug effects on MC were accompanied by cell cycle arrest. Furthermore, CDK4/CDK6 inhibitors were found to synergize with the KIT-targeting drugs midostaurin, avapritinib, and nintedanib in inducing growth inhibition and apoptosis in neoplastic MCs. Finally, we found that CDK4/CDK6 inhibitors induce apoptosis in CD34+/CD38− stem cells in AdvSM. Together, CDK4/CDK6 inhibition is a potent approach to suppress the growth of neoplastic cells in AdvSM. Whether CDK4/CDK6 inhibitors can improve clinical outcomes in patients with AdvSM remains to be determined in clinical trials.

Discovery and Anticancer Activity of Novel 1,3,4-Thiadiazole- and Aziridine-Based Indolin-2-ones via In Silico Design Followed by Supramolecular Green Synthesis

Three crucial anticancer scaffolds, namely indolin-2-one, 1,3,4-thiadiazole, and aziridine, are explored to synthesize virtually screened target molecules based on the c-KIT kinase protein. The stem cell factor receptor c-KIT was selected as target because most U.S. FDA-approved receptor tyrosine kinase inhibitors bearing the indolin-2-one scaffold profoundly inhibit c-KIT. Molecular hybrids of indolin-2-one with 1,3,4-thiadiazole (IIIa-m) and aziridine (VIa and VIc) were afforded through a modified Schiff base green synthesis using β-cyclodextrin-SO₃H in water as a recyclable proton-donor catalyst. A computational study found that indolin-2,3-dione forms a supramolecular inclusion complex with β-cyclodextrin-SO₃H through noncovalent interactions. A molecular docking study of all the synthesized compounds was executed on the c-KIT kinase domain, and most compounds displayed binding affinities similar to that of Sunitinib. On the basis of the pharmacokinetic significance of the aryl thioether linkage in small molecules, 1,3,4-thiadiazole hybrids (IIIa-m) were extended to a new series of 3-((5-(phenylthio)-1,3,4-thiadiazol-2-yl)imino)indolin-2-ones (IVa-m) via thioetherification using bis(triphenylphosphine)palladium(II)dichloride as the catalyst for C-S bond formation. Target compounds were tested against NCI-60 human cancer cell lines for a single-dose concentration. Among all three series of indolin-2-ones, the majority of compounds demonstrated broad-spectrum activity toward various cancer cell lines. Compounds IVc and VIc were further evaluated for a five-dose anticancer study. Compound IVc showed a potent activity of IC₅₀ = 1.47 μM against a panel of breast cancer cell lines, whereas compound VIc exhibited the highest inhibition for a panel of colon cancer cell lines at IC₅₀ = 1.40 μM. In silico ADME property descriptors of all the target molecules are in an acceptable range. Machine learning algorithms were used to examine the metabolites and phase I and II regioselectivities of compounds IVc and VIc, and the results suggested that these two compounds could be potential leads for the treatment of cancer.

Pulmonary Protein Oxidation and Oxidative Stress Modulation by Lemna minor L. in Progressive Bleomycin-Induced Idiopathic Pulmonary Fibrosis

Bleomycin (BLM) administration is associated with multifunctional proteins inflammations and induction of idiopathic pulmonary fibrosis (IPF). Lemna minor L. extract, a free-floating monocot macrophyte possesses antioxidant and anti-inflammatory potential. The aim of the study was to examine the protective effect of L. minor extract on lung protein oxidation and oxidative stress modulation by BLM-induced pulmonary fibrosis in Balb/c mice. For this purpose, the protein carbonyl content, advanced glycation end product, nitroxide protein oxidation (5-MSL), and lipid peroxidation (as MDA and ROS), in lung cells were examined. The histological examinations, collagen deposition, and quantitative measurements of IL-1β, IL-6, and TNF in lung tissues and blood were investigated. Intraperitoneal, BLM administration (0.069 U/mL; 0.29 U/kg b.w.) for 33 days, caused IPF induction in Balb/c mice. Pulmonary combining therapy was administered with L. minor at dose 120 mg/mL (0.187 mg/kg b.w.). L. minor histologically ameliorated BLM induced IPF in lung tissues. L. minor significantly modulated (p < 0.05) BLM-alterations induced in lung hydroxyproline, carbonylated proteins, 5-MSL-protein oxidation. Oxidative stress decreased levels in antioxidant enzymatic and non-enzymatic systems in the lung were significantly regulated (p < 0.05) by L. minor. L. minor decreased the IL-1β, IL-6, and TNF-α expression in lung tissues and plasma. The L. minor improves the preventive effect/defense response in specific pulmonary protein oxidation, lipid peroxidation, ROS identifications, and cytokine modulation by BLM-induced chronic inflammations, and could be a good antioxidant, anti-inflammatory, and anti-fibrotic alternative or IPF prevention involved in their pathogenesis.

Decline in Mast Cell Density During Diffuse Alveolar Damage in Idiopathic Pulmonary Fibrosis

Mast cells (MCs) are known to be involved in the pathogenesis of idiopathic pulmonary fibrosis (IPF), although their role in acute exacerbations of IPF has not been investigated. The aims of the study were to evaluate the numbers of MCs in fibrotic and non-fibrotic areas of lung tissue specimens of idiopathic pulmonary fibrosis (IPF) patients with or without an acute exacerbation of IPF, and to correlate the MC density with clinical parameters. MCs of IPF patients were quantified from surgical lung biopsy (SLB) specimens (n = 47) and lung tissue specimens taken at autopsy (n = 7). MC density was higher in the fibrotic areas of lung tissue compared with spared alveolar areas or in controls. Female gender, low diffusion capacity for carbon monoxide, diffuse alveolar damage, and smoking were associated with a low MC density. MC densities of fibrotic areas had declined significantly in five subjects in whom both SLB in the stable phase and autopsy after an acute exacerbation of IPF had been performed. There were no correlations of MC densities with survival time or future acute exacerbations. The MC density in fibrotic areas was associated with several clinical parameters. An acute exacerbation of IPF was associated with a significant decline in MC counts. Further investigations will be needed to clarify the role of these cells in IPF and in the pathogenesis of acute exacerbation as this may help to identify some potential targets for medical treatment for this serious disease.

Beyond TGFβ1 - novel treatment strategies targeting lung fibrosis

Fibrosis is a key feature of chronic lung diseases and occurs as a consequence of aberrant wound healing. TGFβ1 plays a major role in promoting fibrosis and is the primary target of current treatments that slow, but do not halt or reverse the progression of disease. Accumulating evidence suggests that additional mechanisms, including excessive airway contraction, inflammation and infections including COVID-19, can contribute to fibrosis. This review summarises experimental and clinical studies assessing the potential beneficial effects of novel drugs that possess a unique suite of complementary actions to oppose contraction, inflammation and remodelling, along with evidence that they also limit fibrosis. Translation of these promising findings is critical for the repurposing and development of improved therapeutics for fibrotic lung diseases.

Antifibrotic Role of Nintedanib in Tracheal Stenosis After a Tracheal Wound

OBJECTIVES/HYPOTHESIS

Tracheal stenosis is an obstructive disease of the upper airway that commonly develops as a result of abnormal wound healing. We evaluated the anti-inflammatory and antifibrotic properties of nintedanib on tracheal stenosis both in vitro and in vivo.

STUDY DESIGN

Prospective controlled animal study and in vitro comparative study of human cells.

METHODS

An animal model of tracheal stenosis was induced via tracheal trauma. Postsurgical rats were orally administered with nintedanib (10 or 20 mg/kg/d) or saline (negative control) for 2 weeks, and tracheal specimens were harvested after 3 weeks. Degree of stenosis, collagen deposition, fibrotic surrogate markers expression, and T-lymphocytic infiltration were evaluated. Human fetal lung fibroblast-1 (HFL-1) cells were cultured to determine the effects of nintedanib on changes of cellular biological function induced by transforming growth factor-β1 (TGF-β1).

RESULTS

Rat tracheal stenotic tissues exhibited thickened lamina propria with irregular epithelium, characterized by significantly increased collagen deposition and elevated TGF-β1, collagen I, α-SMA and fibronectin expressions. Nintedanib markedly attenuated the tracheal stenotic lesions, reduced the collagen deposition and the expression of fibrotic marker proteins, and mitigated CD4+ T-lymphocyte infiltration. Additionally, cellular proliferation and migration were decreased dose-dependently in TGF-β1-stimulated HFL-1 cells when treated with nintedanib. Furthermore, nintedanib inhibited TGF-β1-induced HFL-1 differentiation and reduced the mRNA levels of the profibrotic genes. TGF-β1-activated phosphorylation of the TGF-β/Smad2/3 and ERK1/2 pathways were also blocked by nintedanib.

CONCLUSION

Nintedanib effectively prevented tracheal stenosis in rats by inhibiting fibrosis and inflammation. The antifibrotic effect of nintedanib may be achieved by inhibiting fibroblasts' proliferation, migration and differentiation and suppressing the TGF-β1/Smad2/3 and ERK1/2 signaling pathways.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E2496-E2505, 2021.

Regulatory Immune Cells in Idiopathic Pulmonary Fibrosis: Friends or Foes?

The immune system is receiving increasing attention for interstitial lung diseases, as knowledge on its role in fibrosis development and response to therapies is expanding. Uncontrolled immune responses and unbalanced injury-inflammation-repair processes drive the initiation and progression of idiopathic pulmonary fibrosis. The regulatory immune system plays important roles in controlling pathogenic immune responses, regulating inflammation and modulating the transition of inflammation to fibrosis. This review aims to summarize and critically discuss the current knowledge on the potential role of regulatory immune cells, including mesenchymal stromal/stem cells, regulatory T cells, regulatory B cells, macrophages, dendritic cells and myeloid-derived suppressor cells in idiopathic pulmonary fibrosis. Furthermore, we review the emerging role of regulatory immune cells in anti-fibrotic therapy and lung transplantation. A comprehensive understanding of immune regulation could pave the way towards new therapeutic or preventive approaches in idiopathic pulmonary fibrosis.

Hypoxia Inducible Factor 1A Supports a Pro-Fibrotic Phenotype Loop in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with poor prognosis. The IPF-conditioned matrix (IPF-CM) system enables the study of matrix–fibroblast interplay. While effective at slowing fibrosis, nintedanib has limitations and the mechanism is not fully elucidated. In the current work, we explored the underlying signaling pathways and characterized nintedanib involvement in the IPF-CM fibrotic process. Results were validated using IPF patient samples and bleomycin-treated animals with/without oral and inhaled nintedanib. IPF-derived primary human lung fibroblasts (HLFs) were cultured on Matrigel and then cleared using NH₄OH, creating the IPF-CM. Normal HLF-CM served as control. RNA-sequencing, PCR and western-blots were performed. HIF1α targets were evaluated by immunohistochemistry in bleomycin-treated rats with/without nintedanib and in patient samples with IPF. HLFs cultured on IPF-CM showed over-expression of ‘HIF1α signaling pathway’ (KEGG, p < 0.0001), with emphasis on SERPINE1 (PAI-1), VEGFA and TIMP1. IPF patient samples showed high HIF1α staining, especially in established fibrous tissue. PAI-1 was overexpressed, mainly in alveolar macrophages. Nintedanib completely reduced HIF1α upregulation in the IPF-CM and rat-bleomycin models. IPF-HLFs alter the extracellular matrix, thus creating a matrix that further propagates an IPF-like phenotype in normal HLFs. This pro-fibrotic loop includes the HIF1α pathway, which can be blocked by nintedanib.

The Role of Anti-angiogenesis in the Treatment Landscape of Non-small Cell Lung Cancer - New Combinational Approaches and Strategies of Neovessel Inhibition

Tumor progression depends primarily on vascular supply, which is facilitated by angiogenic activity within the malignant tissue. Non-small cell lung cancer (NSCLC) is a highly vascularized tumor, and inhibition of angiogenesis was projected to be a promising therapeutic approach. Over a decade ago, the first anti-angiogenic agents were approved for advanced stage NSCLC patients, however, they only produced a marginal clinical benefit. Explanations why anti-angiogenic therapies only show modest effects include the highly adaptive tumor microenvironment (TME) as well as the less understood characteristics of the tumor vasculature. Today, advanced methods of in-depth characterization of the NSCLC TME by single cell RNA sequencing (scRNA-Seq) and preclinical observations enable a detailed characterization of individual cancer landscapes, allowing new aspects for a more individualized inhibition of angiogenesis to be identified. Furthermore, the tumor vasculature itself is composed of several cellular subtypes, which closely interact with other cellular components of the TME, and show distinct biological functions such as immune regulation, proliferation, and organization of the extracellular matrix. With these new insights, combinational approaches including chemotherapy, anti- angiogenic and immunotherapy can be developed to yield a more target-oriented anti-tumor treatment in NSCLC. Recently, anti-angiogenic agents were also shown to induce the formation of high endothelial venules (HEVs), which are essential for the formation of tertiary lymphoid structures, and key components in triggering anti-tumor immunity. In this review, we will summarize the current knowledge of tumor-angiogenesis and corresponding anti-angiogenic therapies, as well as new aspects concerning characterization of tumor-associated vessels and the resulting new strategies for anti-angiogenic therapies and vessel inhibition in NSCLC. We will further discuss why anti-angiogenic therapies form an interesting backbone strategy for combinational therapies and how anti-angiogenic approaches could be further developed in a more personalized tumor-oriented fashion with focus on NSCLC.

Integrated plasma proteomics and lung transcriptomics reveal novel biomarkers in idiopathic pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease with a significant unmet medical need. Development of transformational therapies for IPF is challenging in part to due to lack of robust predictive biomarkers of prognosis and treatment response. Importantly, circulating biomarkers of IPF are limited and none are in clinical use.

METHODS

We previously reported dysregulated pathways and new disease biomarkers in advanced IPF through RNA sequencing of lung tissues from a cohort of transplant-stage IPF patients (n = 36) in comparison to normal healthy donors (n = 19) and patients with acute lung injury (n = 11). Here we performed proteomic profiling of matching plasma samples from these cohorts through the Somascan-1300 SomaLogics platform.

RESULTS

Comparative analyses of lung transcriptomic and plasma proteomic signatures identified a set of 34 differentially expressed analytes (fold change (FC) ≥  ± 1.5, false discovery ratio (FDR) ≤ 0.1) in IPF samples compared to healthy controls. IPF samples showed strong enrichment of chemotaxis, tumor infiltration and mast cell migration pathways and downregulated extracellular matrix (ECM) degradation. Mucosal (CCL25 and CCL28) and Th2 (CCL17 and CCL22) chemokines were markedly upregulated in IPF and highly correlated within the subjects. The mast cell maturation chemokine, CXCL12, was also upregulated in IPF plasma (fold change 1.92, FDR 0.006) and significantly correlated (Pearson r = - 0.38, p = 0.022) to lung function (%predicted FVC), with a concomitant increase in the mast cell Tryptase, TPSB2. Markers of collagen III and VI degradation (C3M and C6M) were significantly downregulated (C3M p < 0.001 and C6M p < 0.0001 IPF vs control) and correlated, Pearson r = 0.77) in advanced IPF consistent with altered ECM homeostasis.

CONCLUSIONS

Our study identifies a panel of tissue and circulating biomarkers with clinical utility in IPF that can be validated in future studies across larger cohorts.