Thalidomide has a therapeutic effect on interstitial lung fibrosis: evidence from in vitro and in vivo studies

Therapeutic effects of thalidomide on patients with systemic sclerosis-associated interstitial lung disease

Objective

To evaluate the clinical efficacy of thalidomide in patients with systemic sclerosis-associated interstitial lung disease.

Methods

Ninety-six systemic sclerosis-associated interstitial lung disease patients who received basic glucocorticoid treatment and admitted between 2016 and 2020 were included in this study, including 48 cases in the thalidomide group (combination of thalidomide and cyclophosphamide) and 48 cases in control group (cyclophosphamide monotherapy). Evaluation items included clinical symptoms, modified Rodnan skin score, pulmonary function test, chest high-resolution computed tomography scores, and adverse effects between two groups after 24 weeks of treatment.

Results

Remarkable improvements in several aspects were found in the thalidomide group, including modified Rodnan skin score, expiratory dyspnea score, cough visual analog scale score, total ground-glass opacity score, and total interstitial lung disease score. Compared to the control group, improvements in the thalidomide group were found, such as significantly decreased cough visual analog scale score and expectoration; increased number of platelets; improved pulmonary fibrosis (p = 0.056), and reduced carbon monoxide diffusing capacity (p = 0.053). There were no statistically significant differences in the expiratory dyspnea score and predicted forced vital capacity between the two groups. Patients who experienced at least one adverse event in the control group and thalidomide group were 33.3% and 64.6% (p = 0.002); while those with serious adverse events were 8.3% versus 12.5% (p = 0.504). Venous thrombosis was found in one case in the thalidomide group.

Conclusion

Thalidomide combined with cyclophosphamide can improve the symptoms of cough and expectoration in patients with systemic sclerosis-associated interstitial lung disease, and may slightly delay the progression of pulmonary fibrosis, but with the possibility of an increased risk of adverse events.

Thalidomide interaction with inflammation in idiopathic pulmonary fibrosis

The "Thalidomide tragedy" is a landmark in the history of the pharmaceutical industry. Despite limited clinical trials, there is a continuous effort to investigate thalidomide as a drug for cancer and inflammatory diseases such as rheumatoid arthritis, lepromatous leprosy, and COVID-19. This review focuses on the possibilities of targeting inflammation by repurposing thalidomide for the treatment of idiopathic pulmonary fibrosis (IPF). Articles were searched from the Scopus database, sorted, and selected articles were reviewed. The content includes the proven mechanisms of action of thalidomide relevant to IPF. Inflammation, oxidative stress, and epigenetic mechanisms are major pathogenic factors in IPF. Transforming growth factor-β (TGF-β) is the major biomarker of IPF. Thalidomide is an effective anti-inflammatory drug in inhibiting TGF-β, interleukins (IL-6 and IL-1β), and tumour necrosis factor-α (TNF-α). Thalidomide binds cereblon, a process that is involved in the proposed mechanism in specific cancers such as breast cancer, colon cancer, multiple myeloma, and lung cancer. Cereblon is involved in activating AMP-activated protein kinase (AMPK)-TGF-β/Smad signalling, thereby attenuating fibrosis. The past few years have witnessed an improvement in the identification of biomarkers and diagnostic technologies in respiratory diseases, partly because of the COVID-19 pandemic. Hence, investment in clinical trials with a systematic plan can help repurpose thalidomide for pulmonary fibrosis.

MALAT1-miR-30c-5p-CTGF/ATG5 axis regulates silica-induced experimental silicosis by mediating EMT in alveolar epithelial cells

Epithelial-mesenchymal transdifferentiation of alveolar type Ⅱ epithelial cells is a vital source of pulmonary myofibroblasts, and myofibroblasts formation is recognized as an important phase in the pathological process of silicosis. miR-30c-5p has been determined to be relevant in the activation of the epithelial-mesenchymal transition (EMT) in numerous disease processes. However, elucidating the role played by miR-30c-5p in the silicosis-associated EMT process remains a great challenge. In this work, based on the establishment of mouse silicosis and A549 cells EMT models, miR-30c-5p was interfered with in vivo and in vitro models to reveal its effects on EMT and autophagy. Moreover, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), connective tissue growth factor (CTGF), autophagy-related gene 5 (ATG5), and autophagy were further interfered with in the A549 cells models to uncover the possible molecular mechanism through which miR-30c-5p inhibits silicosis associated EMT. The results demonstrated the targeted binding of miR-30c-5p to CTGF, ATG5, and MALAT1, and showed that miR-30c-5p could prevent EMT in lung epithelial cells by acting on CTGF and ATG5-associated autophagy, thereby inhibiting the silicosis fibrosis process. Furthermore, we also found that lncRNA MALAT1 might competitively absorb miR-30c-5p and affect the EMT of lung epithelial cells. In a word, interfering with miR-30c-5p and its related molecules (MALAT1, CTGF, and ATG5-associated autophagy) may provide a reference point for the application of silicosis intervention-related targets.

The mighty fibroblast and its utility in scleroderma research

Fibroblasts are the effector cells of fibrosis characteristic of systemic sclerosis (SSc, scleroderma) and other fibrosing conditions. The excess production of extracellular matrix (ECM) proteins is the hallmark of fibrosis in different organs, such as skin and lung. Experiments designed to assess the pro-fibrotic capacity of factors, their signaling pathways, and potential inhibitors of their effects that are conducted in fibroblasts have paved the way for planning clinical trials in SSc. As such, fibroblasts have proven to be valuable tools in the search for effective anti-fibrotic therapies for fibrosis. Herein we highlight the characteristics of fibroblasts, their role in the etiology of fibrosis, utility in experimental assays, and contribution to drug development and clinical trials in SSc.

Genome-wide DNA methylation analysis in lung fibroblasts co-cultured with silica-exposed alveolar macrophages

Background

Exposure to crystalline silica is considered to increase the risk of lung fibrosis. The primary effector cell, the myofibroblast, plays an important role in the deposition of extracellular matrix (ECM). DNA methylation change is considered to have a potential effect on myofibroblast differentiation. Therefore, the present study was designed to investigate the genome-wide DNA methylation profiles of lung fibroblasts co-cultured with alveolar macrophages exposed to crystalline silica in vitro.

Methods

AM/fibroblast co-culture system was established. CCK8 was used to assess the toxicity of AMs. mRNA and protein expression of collagen I, α-SMA, MAPK9 and TGF-β1 of fibroblasts after AMs exposed to 100 μg /ml SiO₂ for 0–, 24–, or 48 h were determined by means of quantitative real-time PCR, immunoblotting and immunohistochemistry. Genomic DNA of fibroblasts was isolated using MeDIP-Seq to sequence. R software, GO, KEGG and Cytoscape were used to analyze the data.

Results

SiO₂ exposure increased the expression of collagen I and α-SMA in fibroblasts in co-culture system. Analysis of fibroblast methylome identified extensive methylation changes involved in several signaling pathways, such as the MAPK signaling pathway and metabolic pathways. Several candidates, including Tgfb1 and Mapk9, are hubs who can connect the gene clusters. MAPK9 mRNA expression was significantly higher in fibroblast exposed to SiO₂ in co-culture system for 48 h. MAPK9 protein expression was increased at both 24-h and 48-h treatment groups. TGF-β1 mRNA expression of fibroblast has a time-dependent manner, but we didn’t observe the TGF-β1 protein expression.

Conclusion

Tgfb1 and Mapk9 are helpful to explore the mechanism of myofibroblast differentiation. The genome-wide DNA methylation profiles of fibroblasts in this experimental silicosis model will be useful for future studies on epigenetic gene regulation during myofibroblast differentiation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-017-0576-z) contains supplementary material, which is available to authorized users.

Interstitial lung disease in systemic sclerosis: where do we stand?

Interstitial lung disease (ILD) is common in systemic sclerosis (SSc) patients and despite recent advances in the treatment is, at present, the major cause of death. Today, an early diagnosis of ILD is possible, and is mandatory to improve the prognosis of the disease. Pulmonary function tests and high-resolution computed tomography remain the mainstay for the diagnosis of SSc-ILD, but there is a growing interest in lung ultrasound. Recently, the correlation between severity of fibrosis and some peripheral blood biomarkers has been described. Nonselective immunosuppressors are still the main treatment for ILD, with cyclophosphamide (CYC) most widely used to obtain remission. Novel therapies towards specific molecular and cellular targets have been suggested; in particular, rituximab (RTX) has shown promising results, but further research is needed. It is of paramount importance to define the severity of the disease and the risk of progression in order to define the need for treatment and the treatment intensity. We propose the division of the treatment strategies at our disposal to induce remission into three categories: high intensity (haematopoietic stem cell transplantation), medium intensity (CYC and RTX) and low intensity (azathioprine (AZA) and mycophenolate mofetil (MMF)). After obtaining remission, maintenance treatment with AZA or MMF should be started. In this review we explore new advances in the pathogenesis, diagnosis and treatment of SSc-ILD.

The inhibition effect and mechanism of SY0916 on pulmonary fibrosis

SY0916 is a new platelet-activating factor receptor antagonist developed by our institute. In this study, the inhibitory effect of SY0916 on pulmonary fibrosis was investigated in epithelial-mesenchymal transition (EMT) induced by transforming growth factor beta 1 (TGF-β1) in vitro and a pulmonary fibrosis animal model induced by bleomycin (BLM). The results showed that SY0916 could inhibit the EMT of A549 cells induced with TGF-β1. In vivo, SY0916 administration significantly ameliorated the BLM-mediated histological changes, reduced main biochemical parameters related to pulmonary fibrosis such as hydroxyproline and glutathione, and also notably attenuated the expression of key pro-fibrotic mediator, TGF-β1. These findings demonstrated that SY0916 could possibly be developed as a promising candidate for the treatment of pulmonary fibrosis.

Protease-activated receptor-2 induces myofibroblast differentiation and tissue factor up-regulation during bleomycin-induced lung injury: potential role in pulmonary fibrosis

Idiopathic pulmonary fibrosis constitutes the most devastating form of fibrotic lung disorders and remains refractory to current therapies. The coagulation cascade is frequently activated during pulmonary fibrosis, but this observation has so far resisted a mechanistic explanation. Recent data suggest that protease-activated receptor (PAR)-2, a receptor activated by (among others) coagulation factor (F)Xa, plays a key role in fibrotic disease; consequently, we assessed the role of PAR-2 in the development of pulmonary fibrosis in this study. We show that PAR-2 is up-regulated in the lungs of patients with idiopathic pulmonary fibrosis and that bronchoalveolar lavage fluid from these patients displays increased procoagulant activity that triggers fibroblast survival. Using a bleomycin model of pulmonary fibrosis, we show that bleomycin induces PAR-2 expression, as well as both myofibroblast differentiation and collagen synthesis. In PAR-2-/- mice, both the extent and severity of fibrotic lesions are reduced, whereas myofibroblast differentiation is diminished and collagen expression is decreased. Moreover, fibrin deposition in the lungs of fibrotic PAR-2-/- mice is reduced compared with wild-type mice due to differential tissue factor expression in response to bleomycin. Taken together, these results suggest an important role for PAR-2 in the development of pulmonary fibrosis, and the inhibition of the PAR-2-coagulation axis may provide a novel therapeutic approach to treat this devastating disease.